24,909 results on '"XU Lei"'
Search Results
2. A review of lithium-ion battery state of health and remaining useful life estimation methods based on bibliometric analysis
- Author
-
Xu Lei, Fangjian Xie, Jialong Wang, and Chunling Zhang
- Subjects
Lithium-ion battery ,State of health ,Remaining useful life ,Estimation ,Bibliometric analysis ,Transportation engineering ,TA1001-1280 - Abstract
In recent years, research on the state of health (SOH) and remaining useful life (RUL) estimation methods for lithium-ion batteries has garnered significant attention in the new energy sector. Despite the substantial volume of annual publications, a systematic approach to quantifying and analyzing these contributions is lacking. This study focuses on selecting pertinent literature related to lithium-ion battery SOH and RUL estimation from CNKI and WOS databases, spanning January 2010 to December 2023. Employing bibliometric tools such as VOSviewer and CiteSpace, we conduct visual analyses to elucidate the current state, development trends, and research frontiers in this domain. Our examination encompasses scholarly activity, year-wise literature distribution, international collaboration networks, structural dissemination, and journal contributions. The findings indicate an upward trend in annual publication output, with China, the United States, the United Kingdom, and Canada at the forefront of collaborative research efforts. China is increasingly recognized as a pivotal hub for global scholarly partnerships. Notably, Harbin Institute of Technology, Beijing Institute of Technology, Chongqing University, Chinese Academy of Sciences, and Beijing Jiaotong University are the top institutions in China and the world in terms of publications. The Journal of Energy Storage emerges as a prominent periodical, acclaimed both domestically and internationally for its rigorous standards and high-quality articles. Based on the research content from CNKI and WOS, VOSviewer clusters the main research directions into three themes: aging mechanisms, SOH estimation methods, and RUL prediction methods. Keywords such as ‘online estimation’, ‘hybrid models’, and ‘artificial neural networks’ feature prominently, signaling a strong emphasis on artificial intelligence strategies. The study concludes with a prospective outlook on imminent research trajectories regarding the health and longevity estimations of lithium-ion batteries, highlighting the critical need for ongoing innovation and collaboration in this essential field.
- Published
- 2024
- Full Text
- View/download PDF
3. Edge-centric connectome-genetic markers of bridging factor to comorbidity between depression and anxiety
- Author
-
Zhiyi Chen, Yancheng Tang, Xuerong Liu, Wei Li, Yuanyuan Hu, Bowen Hu, Ting Xu, Rong Zhang, Lei Xia, Jing-Xuan Zhang, Zhibing Xiao, Ji Chen, Zhengzhi Feng, Yuan Zhou, Qinghua He, Jiang Qiu, Xu Lei, Hong Chen, Shaozheng Qin, and Tingyong Feng
- Subjects
Science - Abstract
Abstract Depression-anxiety comorbidity is commonly attributed to the occurrence of specific symptoms bridging the two disorders. However, the significant heterogeneity of most bridging symptoms presents challenges for psychopathological interpretation and clinical applicability. Here, we conceptually established a common bridging factor (cb factor) to characterize a general structure of these bridging symptoms, analogous to the general psychopathological p factor. We identified a cb factor from 12 bridging symptoms in depression-anxiety comorbidity network. Moreover, this cb factor could be predicted using edge-centric connectomes with robust generalizability, and was characterized by connectome patterns in attention and frontoparietal networks. In an independent twin cohort, we found that these patterns were moderately heritable, and identified their genetic connectome-transcriptional markers that were associated with the neurobiological enrichment of vasculature and cerebellar development, particularly during late-childhood-to-young-adulthood periods. Our findings revealed a general factor of bridging symptoms and its neurobiological architectures, which enriched neurogenetic understanding of depression-anxiety comorbidity.
- Published
- 2024
- Full Text
- View/download PDF
4. Improving the flow pattern in the inlet forebay with diffusion angle in the Xuliu Irrigation Station
- Author
-
XU Pengfei, DUAN Hongfei, ZHANG Yunfeng, TAO Juan, ZHU Bo, and XU Lei
- Subjects
xuliu irrigation station ,forebay ,large diffusion angle ,flow pattern ,rectification measures ,numerical simulation ,Agriculture (General) ,S1-972 ,Irrigation engineering. Reclamation of wasteland. Drainage ,TC801-978 - Abstract
【Objective】 The inlet forebay with a diffusion angle is a component of pump stations that helps distribute water flow evenly before it reaches the pump. We present a method in this paper to optimize the design of the inlet forebay, using the Xuliu Irrigation Station as a case study. 【Method】 The proposed method utilized the Navier-Stokes equations and the RNG k-ε turbulence model. Three-dimensional water flow in the forebay was numerically simulated under various scenarios, including the current configuration, modifications to the guide walls, and the addition of support columns. The optimal forebay design was determined by comparing the flow patterns generated in each scenario. 【Result】 Both guide walls and support columns improve flow patterns. Installing support columns increases the uniformity of average axial flow velocity distribution and the velocity-weighted average angle at the channel outlet to 97.74% and 88.42°, respectively, slightly surpassing the performance of the guide wall scheme and improving by 1.14% and 1.25° over the current configuration. At the channel inlet, the uniformity of average axial flow velocity distribution and velocity-weighted average angle were 62.86% and 65.82°, respectively, which were significantly higher than those achieved with the guide wall scheme and represented increases of 26.4% and 36.9° over the current configuration. The support column scheme also reduced the proportion of the vortex area in the forebay to 5%, compared to 7% with the guide wall scheme and 45% with the current configuration. 【Conclusion】 Installing support columns effectively improves the uniformity of water flow diffusion and reduces vortex areas, enhancing flow patterns in the forebay compared to the guide wall scheme. These results provide guidance for renovating the forebay at the Xuliu Irrigation Station and similar irrigation projects.
- Published
- 2024
- Full Text
- View/download PDF
5. Advantages of the split-leg supine position single-port plus one laparoscopic surgery approach
- Author
-
Wang Xin, Yu Yongkui, Qin Zimin, Xu Lei, Wang Haojie, Xie Jinyi, Wu Yiju, Xu Zihou, Chen Peinan, Liu Qi, Li Haomiao, Wang Zongfei, Chen Yongfeng, Xing Wenqun, and Meng Fanyu
- Subjects
Split-leg supine position ,Single-port plus one laparoscopic surgery ,Esophageal cancer ,Medicine ,Science - Abstract
Abstract The goal of this study was to compare the advantages of conventional laparoscopic surgery (CLS) and the split-leg supine position single-port plus one laparoscopic surgery (SSP SILS + 1) in esophageal surgery. This study enrolled 73 patients who previously underwent radical esophagectomy for esophageal cancer from August 2021 to February 2023. Among them, 36 patients underwent SSP SILS + 1, whereas the remaining 37 patients underwentCLS. Surgical time, bleeding volume, number of dissected lymph nodes, incision length, and postoperative abdominal pain score between the two groups of patients were compared using either the Student’s t-test or chi-square test. Time of abdominal incision (1.4 ± 0.2 min vs. 5.2 ± 0.7 min, p 0.01) between the two groups. The SSP SILS + 1 intervention offers multiple benefits over conventional surgical procedures, encompassing shorter incision length and pain scores on POD 1. In accelerated rehabilitation surgery for esophageal cancer, this surgical procedure demonstrated high safety, feasibility.
- Published
- 2024
- Full Text
- View/download PDF
6. Effects of compound fungi inoculant application on growth, root configuration, and photosynthetic characteristics of Chinese flowering cabbage cultivated in continuous cropping soil
- Author
-
XU Lei, WANG Jitao, DING Zengwei, LUO Yuan, CHEN Qiwei, and YE Lin
- Subjects
chinese flowering cabbage ,continuous cropping ,compound bacterial agents ,growth ,root system configuration ,photosynthetic characteristics ,Biology (General) ,QH301-705.5 ,Botany ,QK1-989 - Abstract
Abstract [Objective] The study aims to explore the effects of compound fungi inoculant application on the growth, root morphology, and photosynthetic characteristics of Chinese flowering cabbage seedlings, and provide a theoretical basis for the application of compound fungi inoculant to alleviate the obstacle of continuous cropping of Chinese flowering cabbage. [Methods] The Chinese flowering cabbage variety ‘Jianye- 70’, with which microbial agents and soil had been continuously cropped for 9 years, were used in pot experiments. Four treatments were set up: No compound microbial agents (control), foliar spraying, soil spraying, and foliar spraying plus soil spraying. The plant growth indicators, root system configuration, and leaf photosynthetic characteristics were observed after sowing for 30 days. [Results] Every application method could increase growth indicators, root system conformation, leaf photosynthetic characteristics net photosynthetic rate (Pn), actual photochemical efficiency (ΦPSⅡ ), and photochemical quenching coefficient (qp) etc., as well as decrease transpiration rate (Tr), intercellular carbon dioxide concentration (Ci), and non photochemical quenching coefficient (NPQ) etc. Among the application methods, foliar spraying had the best effect. Its above-ground and underground dry weight and root length were significantly increased by 128.57%, 85.71%, and 91.81%. Pn, qp, and ΦPSⅡ were significantly increased by 24.55%, 22.68%, and 23.93%, while Tr, Ci, and NPQ were significantly decreased by 72.73%, 20.01%, and 39.78%, respectively. [Conclusion] Foliar spraying of compound fungi can effectively promote the growth of continuous cropping cabbage seedlings, improve root configuration, enhance plant photosynthetic efficiency, which is the best way of compound fungi application
- Published
- 2024
- Full Text
- View/download PDF
7. Association between hs-CRP/HDL-C ratio and three-month unfavorable outcomes in patients with acute ischemic stroke: a second analysis based on a prospective cohort study
- Author
-
Huang Luwen, Xu Lei, Ouyang Qing-Rong, Li Linlin, and Yu Ming
- Subjects
Acute ischemic stroke ,hs-CRP/HDL-C ,Prognosis ,Association ,mRS ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Objective The associations between the ratio of blood high-sensitivity C-reactive protein (hs-CRP) to high-density lipoprotein cholesterol (HDL-C) (hs-CRP/HDL-C ratio) and outcomes in patients with acute ischemic stroke (AIS) have yet to be established. This study is the first to examine the relationship between the hs-CRP/HDL-C ratio and three-month unfavorable outcomes in patients with AIS. Methods This secondary analysis utilized data from a prospective cohort study involving 1559 AIS patients recruited at a South Korean hospital between January 2010 and December 2016. We constructed a binary logistic regression model to explore the association between the hs-CRP/HDL-C ratio and unfavorable outcomes in patients with AIS. An attempt was made to use a generalized additive model (GAM) with smooth curve fitting to elucidate potential nonlinear interactions. Furthermore, inflection points were identified via a recursive method, and binary logistic regression models were developed for each side of these inflection points. Ultimately, a log-likelihood ratio test was used to identify the most appropriate model for explaining the connection between the hs-CRP/HDL-C ratio and unfavorable outcomes in patients with AIS. Results The incidence of unfavorable outcomes was 24.5%, with a median hs-CRP/HDL-C ratio of 3.64. After accounting for other factors, the binary logistic regression model revealed a statistically significant positive association between the hs-CRP/HDL-C ratio and the likelihood of poor outcomes in AIS patients (OR = 1.013, 95% CI: 1.005–1.022; P = 0.002). A nonlinear relationship was observed, with the first inflection point of the hs-CRP/HDL-C ratio at 42.74. Each 1-unit increase in the hs-CRP/HDL-C ratio was associated with a 2.4% greater risk of unfavorable outcomes (OR = 1.024, 95% CI: 1.011–1.038, P
- Published
- 2024
- Full Text
- View/download PDF
8. Ventilatory pressure parameters impact the association between acute gastrointestinal injury and all-cause mortality in mechanically ventilated patients
- Author
-
Shao Ziqiang, Li Jiale, Sun Renhua, Wu Aiping, Ni Yin, Liu Jingquan, Guo Feng, Ying Lijun, Ge Guoping, Ding Aijun, Shi Yunchao, Liu Changwen, Xu Lei, Jiang Ronglin, Lu Jun, Lin Ronghai, Zhu Yannan, Wu Weidong, Xie Bo, and Hu Bangchuan
- Subjects
Mechanical ventilation ,Acute gastrointestinal injury ,All-cause mortality ,Plateau pressure ,Driving pressure ,Positive end-expiratory pressure ,Medicine ,Science - Abstract
Abstract Acute gastrointestinal injury (AGI) is common in mechanically ventilated (MV) patients, but the potential association between ventilatory pressure parameters and AGI grade and their impact on mortality remains unclear. This study aimed to explore the association between ventilatory pressure parameters and AGI grade, and their interaction on all-cause mortality in MV patients. This study was a secondary analysis of a multicenter, prospective, observational study that enrolled adult patients with an expected duration of mechanical ventilation ≥ 48 h from 14 general intensive care units in Zhejiang Province between March and August 2014. The AGI grade was assessed daily on the basis of gastrointestinal symptoms, intra-abdominal pressures, and feeding intolerance in the first week of admission to the ICU. This study included 331 patients (69.2% men; mean age, 64.6 ± 18.9 years). Multivariate regression analysis showed that plateau pressure (Pplat) (OR 1.044, 95% CI 1.009–1.081, P = 0.013), serum creatinine (OR 1.003, 95% CI 1.001–1.006, P = 0.042) and APACHE II score (OR 1.035, 95% CI 1.021–1.072, P = 0.045) were independently associated with global AGI grade III/IV within 7 days of ICU admission. Moreover, global AGI grade (HR 2.228, 95% CI 1.561–3.182, P
- Published
- 2024
- Full Text
- View/download PDF
9. Semantic associative abilities and executive control functions predict novelty and appropriateness of idea generation
- Author
-
Xueyang Wang, Qunlin Chen, Kaixiang Zhuang, Jingyi Zhang, Robert A. Cortes, Daniel D. Holzman, Li Fan, Cheng Liu, Jiangzhou Sun, Xianrui Li, Yu Li, Qiuyang Feng, Hong Chen, Tingyong Feng, Xu Lei, Qinghua He, Adam E. Green, and Jiang Qiu
- Subjects
Biology (General) ,QH301-705.5 - Abstract
Abstract Novelty and appropriateness are two fundamental components of creativity. However, the way in which novelty and appropriateness are separated at behavioral and neural levels remains poorly understood. In the present study, we aim to distinguish behavioral and neural bases of novelty and appropriateness of creative idea generation. In alignment with two established theories of creative thinking, which respectively, emphasize semantic association and executive control, behavioral results indicate that novelty relies more on associative abilities, while appropriateness relies more on executive functions. Next, employing a connectome predictive modeling (CPM) approach in resting-state fMRI data, we define two functional network-based models—dominated by interactions within the default network and by interactions within the limbic network—that respectively, predict novelty and appropriateness (i.e., cross-brain prediction). Furthermore, the generalizability and specificity of the two functional connectivity patterns are verified in additional resting-state fMRI and task fMRI. Finally, the two functional connectivity patterns, respectively mediate the relationship between semantic association/executive control and novelty/appropriateness. These findings provide global and predictive distinctions between novelty and appropriateness in creative idea generation.
- Published
- 2024
- Full Text
- View/download PDF
10. Morroniside promotes skin wound re-epithelialization by facilitating epidermal stem cell proliferation through GLP-1R-mediated upregulation of β-catenin expression
- Author
-
Yu Chenghao, Yu Siyuan, Liu Zuohua, Xu Lei, Zhang Zhiqiang, Wan Jiaming, Ji Pengxiang, Zhang Ping, Fu Yi, Le Yingying, and Hou Ruixing
- Subjects
morroniside ,wound healing ,epidermal stem cells ,cell proliferation ,glucagon-like peptide-1 receptor ,β-catenin ,Biochemistry ,QD415-436 ,Genetics ,QH426-470 - Abstract
Epidermal stem cells (EpSCs) play a vital role in skin wound healing through re-epithelialization. Identifying chemicals that can promote EpSC proliferation is helpful for treating skin wounds. This study investigates the effect of morroniside on cutaneous wound healing in mice and explores the underlying mechanisms. Application of 10‒50 μg/mL of morroniside to the skin wound promotes wound healing in mice. In vitro studies demonstrate that morroniside stimulates the proliferation of mouse and human EpSCs in a time- and dose-dependent manner. Mechanistic studies reveal that morroniside promotes the proliferation of EpSCs by facilitating the cell cycle transition from the G1 to S phase. Morroniside increases the expression of β-catenin via the glucagon-like peptide-1 receptor (GLP-1R)-mediated PKA, PKA/PI3K/AKT and PKA/ERK signaling pathways, resulting in an increase in cyclin D1 and cyclin E1 expression, either directly or by upregulating c-Myc expression. This process ultimately leads to EpSC proliferation. Administration of morroniside to mouse skin wounds increases the phosphorylation of AKT and ERK, the expressions of β-catenin, c-Myc, cyclin D1, and cyclin E1, as well as the proliferation of EpSCs, in periwound skin tissue, and accelerates wound re-epithelialization. These effects of morroniside are mediated by the GLP-1R. Overall, these results indicate that morroniside promotes skin wound healing by stimulating the proliferation of EpSCs via increasing β-catenin expression and subsequently upregulating c-Myc, cyclin D1, and cyclin E1 expressions through GLP-1R signaling pathways. Morroniside has clinical potential for treating skin wounds.
- Published
- 2024
- Full Text
- View/download PDF
11. Enhanced diversity on connector hubs following sleep deprivation: Evidence from diffusion and functional magnetic resonance imaging
- Author
-
Yun Tian, Xue-Rui Peng, Zihan Tang, Zhiliang Long, Chao Xie, and Xu Lei
- Subjects
Functional connectivity ,Structural connectivity ,Connector hub ,Sleep deprivation ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Sleep deprivation has been demonstrated to exert widespread and intricate impacts on the brain network. The human brain network is a modular network composed of interconnected nodes. This network consists of provincial hubs and connector hubs, with provincial hubs having diverse connectivities within their own modules, while connector hubs distribute their connectivities across different modules. The latter is crucial for integrating information from various modules and ensuring the normal functioning of the modular brain. However, there has been a lack of systematic investigation into the impact of sleep deprivation on brain connector hubs. In this study, we utilized functional connectivity from resting-state functional magnetic resonance imaging, as well as structural connectivity from diffusion-weighted imaging, to systematically explore the variation of connector hub properties in the cerebral cortex after one night of sleep deprivation. The normalized participation coefficients (PCnorm) were utilized to identify connector hubs. In both the functional and structural networks, connector hubs exhibited a significant increase in average PCnorm, indicating the diversity enhancement of the connector hub following sleep deprivation. This enhancement is associated with increased network cost, reduced modularity, and decreased small-worldness, but enhanced global efficiency. This may potentially signify a compensatory mechanism within the brain following sleep deprivation. The significantly affected connector hubs were primarily observed in both the Control Network and Salience Network. We believe that the observed results reflect the increasing demand on the brain to invest more effort at preventing performance deterioration after sleep loss, in exchange for increased communication efficiency, especially involving systems responsible for neural resource allocation and cognitive control. These results have been replicated in an independent dataset. In conclusion, this study has enhanced our understanding of the compensatory mechanism in the brain response to sleep deprivation. This compensation is characterized by an enhancement in the connector hubs responsible for inter-modular communication, especially those related to neural resource and cognitive control. As a result, this compensation comes with a higher network cost but leads to an improvement in global communication efficiency, akin to a more random-like network manner.
- Published
- 2024
- Full Text
- View/download PDF
12. A resting-state EEG dataset for sleep deprivation
- Author
-
Chuqin Xiang, Xinrui Fan, Duo Bai, Ke Lv, and Xu Lei
- Subjects
Science - Abstract
Abstract To investigate the impact of sleep deprivation (SD) on mood, alertness, and resting-state electroencephalogram (EEG), we present an eyes-open resting-state EEG dataset. The dataset comprises EEG recordings and cognitive data from 71 participants undergoing two testing sessions: one involving SD and the other normal sleep. In each session, participants engaged in eyes-open resting-state EEG. The Psychomotor Vigilance Task (PVT) was employed for alertness measurement. Emotional and sleepiness were measured using Positive and Negative Affect Scale (PANAS) and Stanford Sleepiness Scale (SSS). Additionally, to examine the influence of individual sleep quality and traits on SD, Pittsburgh Sleep Quality Index (PSQI) and Buss-Perry Aggression Questionnaire (BPAQ) were utilized. This dataset’s sharing may contribute to open EEG measurements in the field of SD.
- Published
- 2024
- Full Text
- View/download PDF
13. An adaptability evaluation method for voltage regulation measures in distribution networks based on interval and probability power flow analysis
- Author
-
QIU Dong, JIA Yongyong, HAN Shaohua, ZHU Dandan, and XU Lei
- Subjects
interval power flow ,probability power flow ,the optimal reactive power dispatch ,ahp ,adaptability evaluation of voltage regulation measures ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
With the large-scale integration of renewable energy, distribution networks are faced with frequent voltage limit violations. In response to this challenge, it is urgent to study whether new voltage regulation measures, represented by photovoltaic inverters, can meet the daily voltage regulation needs of distribution networks. To objectively evaluate the adaptability of voltage regulation measures in distribution systems, a method based on interval and probability power flow analysis is proposed. This method enables a comprehensive analysis of voltage regulation effectiveness and cost. Firstly, based on the results of interval and probability power flow, indicators for voltage regulation effectiveness evaluation in distribution networks are constructed. Secondly, the corresponding cost of the optimal reactive power scheme is used as the cost benchmark value to construct the evaluation index of the voltage regulation cost of the distribution network. On this basis, the analytic hierarchy process (AHP) is employed to weight the effectiveness and cost indicators and thus establish a comprehensive evaluation indicator system for voltage regulation adaptability in distribution network. Finally, based on the constructed evaluation indicators, adaptability analysis of voltage regulation measures in distribution networks is conducted. The rationality of the proposed method is validated through comparative evaluations under multiple scenarios.
- Published
- 2024
- Full Text
- View/download PDF
14. Single-layer outer edge waterflooding development model of complex fault block reservoirs with high water cut
- Author
-
YAO Xiutian, XU Lei, WANG Ranran, YAN Sen, WANG Mingpeng, and YANG Qinwen
- Subjects
single-layer outer edge waterflooding ,development model ,periodic waterflooding ,numerical simulation ,complex fault block reservoir ,Chemical technology ,TP1-1185 ,Petroleum refining. Petroleum products ,TP690-692.5 ,Geology ,QE1-996.5 - Abstract
In the late stage of development, the complex fault block reservoir faces a series of problems, such as high comprehensive water cut, lack of formation energy, complex remaining oil distribution, and poor well pattern suitability. In this paper, based on the oil-water distribution status of the waterflooding reservoir, such as water-in-oil and oil-in-water, the development mode of single-layer outer edge waterflooding was studied through theoretical model derivation and numerical simulation methods by taking Ken71 fault block reservoir in the middle of Zhanhua Sag of Jiyang Depression as an example. The results show that the reasonable water injection volume, fluid production volume, and spacing between injection and production wells during single-layer development can be obtained through the force analysis of the fluid production end and the water injection end. The key factors affecting the remaining oil saturation and the water saturation are reasonable water injection pressure difference, water injection volume, and fluid production volume of single-layer development systems. It is essential in controlling the reasonable formation pressure level and the secondary enrichment of the remaining oil. The spacing between injection and production wells increases to the periphery of the oil-water boundary, and 2.9 times the width of the oil-bearing strip is the critical value of reasonable spacing between injection and production wells. An asymmetric periodic injection and production method with short injection and long standing is adopted to establish a single-layer outer edge waterflooding development model, which is beneficial to maintain the stability of the pressure system and increase the sweep efficiency of the remaining oil of the single-layer, so as to improve the oil recovery. Field application shows that after applying the single-layer outer edge waterflooding development model, the daily production of Ken71 fault block increases to 254 t, the water cut is controlled to 93.7%, the recovery increases to 31.53%, and the oil recovery rate is increased by 4.9%, which shows an excellent yield-increasing effect. The single-layer outer edge waterflooding model solves the problems in the development of complex fault block reservoirs with high water cut, such as dispersed remaining oil distribution, low waterflooding sweep efficiency, and poor well pattern suitability and can provide guidance and reference for complex fault block reservoir development.
- Published
- 2024
- Full Text
- View/download PDF
15. A Study on Panoramic Camera System of ROV Platform
- Author
-
GUO Xu, TU Shaoping, and XU Lei
- Subjects
panoramic imaging ,underwater rov ,image processing ,data transmission ,Control engineering systems. Automatic machinery (General) ,TJ212-225 ,Technology - Abstract
Unlike imaging in air, underwater panoramic imaging faces great challenges arising from water pressure and diminished light, necessitating special lens packaging and focused underwater illumination. The processing of underwater images from multiple channels necessitates adaptations to existing image processing algorithms to mitigate color cast, noisy points, and other imaging defects. And based on the hot research of panoramic video transmission, the underwater panoramic imaging system on the ROV platform holds great development potential.Based on the technical research of underwater panoramic photography, this paper first elaborates on the generation and transmission of underwater panoramic images and discusses two camera layouts: distributed and integrated, utilizing the remotely operated vehicle (ROV) platform as the carrier, through an analysis of camera hardware requirements. Subsequently, it introduces the creation of panoramic images from multiple channels of image data through a process involving image preprocessing, stitching, and fusion. Lastly, taking into account of remote video transmission through water boundaries, a self-adaptive multi-rate transmission scheme is presented, based on the stream division into slices (Tile stream) for panoramic videos. From the development of underwater panoramic technology, with the improvement of panoramic technologies such as lossless image stitching, iterative computing speed of image processors, image restoration, ultra bandwidth connection, and panoramic video transmission, ROV platform panoramic camera systems will be widely applied.
- Published
- 2024
- Full Text
- View/download PDF
16. Understanding Fatigue, Insomnia, and COVID-19 PTSS Among Mainland Chinese During Initial Post-Zero-COVID Infection Wave: A Multi-Group Analysis
- Author
-
Shuo Wang, Yuanyuan Xu, Simon Theodor Jülich, Linman Weng, Qiao Jin, Yuxian Wei, and Xu Lei
- Subjects
insomnia symptoms ,fatigue ,COVID-19 PTSS ,infected and uninfected comparison ,Psychology ,BF1-990 - Abstract
In early 2023, China experienced its first widespread COVID-19 outbreak after a policy shift. This study examines the relationship between fatigue and COVID-19-related post-traumatic stress symptoms (PTSS) in infected and uninfected individuals, exploring the potential mediating role of insomnia symptoms. An online survey of 5953 Chinese participants was conducted from 10 to 16 January 2023. Participants reported their COVID-19 infection status, fatigue, insomnia symptoms, and PTSS. Multi-group structural equation modeling (SEM) was used to test whether the mediation paths differed between infected and uninfected groups. The prevalence of fatigue, insomnia symptoms, and COVID-19 PTSS were 30.0%, 36.4%, and 5.8%. The SEM based on the bootstrapping showed that after controlling for demographics, chronic fatigue positively associated with COVID-19 PTSS in a significant way, with insomnia symptoms playing a mediating role. The multi-group analyses further revealed a partial mediation effect of insomnia symptoms on the relationship between fatigue and COVID-19 PTSS in the uninfected group (UG). However, for the infected group (IG), insomnia symptoms fully mediated the relationship between fatigue and COVID-19 PTSS. Infected individuals were more subject to the aforementioned mechanism than uninfected individuals. Addressing chronic fatigue, insomnia, and developing targeted interventions are crucial for supporting mental health across different infection statuses.
- Published
- 2024
- Full Text
- View/download PDF
17. miR-153 promotes neural differentiation by activating the cell adhesion/Ca2+ signaling pathway and targeting ion channel activity in HT-22 cells by bioinformatic analysis
- Author
-
Li Jiao, Zhang Junfang, Li Yanna, Jin Caixia, Zhang Chen, Jia Song, Xu Jie, Yan Xiaoli, Gui Xin, Xing Libo, Wang Feng, Lu lixia, Xu Chunli, and Xu Lei
- Subjects
miR-153 ,Bioinformatic analysis ,Neural differentiation ,Neural cell adhesion ,Receptor tyrosine kinase ,Ion channel ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
MicroRNAs have been studied extensively in neurodegenerative diseases. In a previous study, miR-153 promoted neural differentiation and projection formation in mouse hippocampal HT-22 cells. However, the pathways and molecular mechanism underlying miR-153-induced neural differentiation remain unclear. To explore the molecular mechanism of miR-153 on neural differentiation, we performed RNA sequencing on miR-153-overexpressed HT-22 cells. Based on RNA sequencing, differentially expressed genes (DEGs) and pathways in miR-153-overexpressed cells were identified. The Database for Annotation, Visualization and Integrated Discovery and Gene Set Enrichment Analysis were used to perform functional annotation and enrichment analysis of DEGs. Targetscan predicted the targets of miR-153. The Search Tool for the Retrieval of Interacting Genes and Cytoscape, were used to construct protein-protein interaction networks and identify hub genes. Q-PCR was used to detect mRNA expression of the identified genes. The expression profiles of the identified genes were compared between embryonic days 9.5 (E9.5) and E11.5 in the embryotic mouse brain of the GDS3442 dataset. Cell Counting Kit-8 assay was used to determine cell proliferation and cellular susceptibility to amyloid β-protein (Aβ) toxicity in miR-153-overexpressed cells. The results indicated that miR-153 increased cell adhesion/Ca2+ (Cdh5, Nrcam, and P2rx4) and Bdnf/Ntrk2 neurotrophic signaling pathway, and decreased ion channel activity (Kcnc3, Kcna4, Clcn5, and Scn5a). The changes in the expression of the identified genes in miR-153-overexpressed cells were consistent with the expression profile of GDS3442 during neural differentiation. In addition, miR-153 overexpression decreased cellular susceptibility to Aβ toxicity in HT-22 cells. In conclusion, miR-153 overexpression may promote neural differentiation by inducing cell adhesion and the Bdnf/Ntrk2 pathway, and regulating electrophysiological maturity by targeting ion channels. MiR-153 may play an important role in neural differentiation; the findings provide a useful therapeutic direction for neurodegenerative diseases.
- Published
- 2024
- Full Text
- View/download PDF
18. Green formulation of copper nanoparticles by Pistacia khinjuk leaf aqueous extract: Introducing a novel chemotherapeutic drug for the treatment of prostate cancer
- Author
-
Wang Zhuoqun, Li Ming, Zhang Qi, and Xu Lei
- Subjects
copper nanoparticles ,cytotoxicity ,pistacia khinjuk ,prostate cancer ,Chemistry ,QD1-999 - Abstract
Prostate cancer is a cancer prevalent form characterized by serious clinical symptoms. The discovery of a novel supplement or medication for prostate cancer within the realm of chemotherapeutic drugs holds significant value. Our research involved the synthesis of copper nanoparticles (CuNPs) infused with Pistacia khinjuk leaf extract to explore their potential anti-prostate cancer, cytotoxic, and antioxidant properties. The green-formulated CuNPs were characterized by TEM, UV-Vis spectrophotometry, FE-SEM, FTIR. The FE-SEM and TEM findings prove the spherical structure with a size of 10–70 nm. The DPPH assay was carried out to examine the effectiveness of antioxidants. CuNPs exhibited the ability to inhibit 50% of DPPH at 215 µg/mL. To assess the anti-prostate cancer properties of CuNPs, an MTT assay was performed on NCI-H660, DU 145, LNCaP clone FGC, and LNCaP clone FGC-Luc2 cells. CuNPs exhibited remarkable efficacy in inhibiting prostate cancer growth, while demonstrating negligible toxicity towards normal cells. The LNCaP clone FGC cell line displayed the most potent anti-prostate cancer effects of CuNPs. IC50 of CuNPs was 322, 365, 247, and 273 on NCI-H660, DU 145, LNCaP clone FGC, and LNCaP clone FGC-Luc2 prostate cancer cells. CuNPs containing Pistacia khinjuk were found to possess noteworthy anti-prostate carcinoma characteristics and presented excellent antioxidant potentials, as highlighted by this study.
- Published
- 2024
- Full Text
- View/download PDF
19. An Optimization Method for Thrust Allocation of ROV Based on Genetic Algorithm
- Author
-
XU Lei, SONG Junhui, TU Shaoping, ZHU Jun, and LI Renxiong
- Subjects
rov ,pseudo inverse method ,thrust allocation ,genetic algorithm ,simulation analysis ,Control engineering systems. Automatic machinery (General) ,TJ212-225 ,Technology - Abstract
To address the problem of output saturation in the thrust allocation of remotely operated vehicles (ROVs), this paper introduces a thrust distribution optimization technique based on genetic algorithm. Initially, a mathematical model describing the horizontal and vertical thrust of an ROV is established, using the spatial configuration of a miniaturized electric ROV's propellers as foundation. Subsequently, genetic algorithm is employed to optimize thrust allocation for the ROV's horizontal and vertical propellers, with results compared to outcomes from a pseudo-inverse method of thrust allocation. Simulation analysis reveals that the thrust allocation optimized via the genetic algorithm can effectively prevent output saturation and ensures that the resultant force or torque from each propeller's output aligns almost exactly with the intended combined force or torque, maintaining an error within ±1%.
- Published
- 2023
- Full Text
- View/download PDF
20. Covariance patterns between sleep health domains and distributed intrinsic functional connectivity
- Author
-
Yulin Wang, Sarah Genon, Debo Dong, Feng Zhou, Chenyu Li, Dahua Yu, Kai Yuan, Qinghua He, Jiang Qiu, Tingyong Feng, Hong Chen, and Xu Lei
- Subjects
Science - Abstract
Abstract Sleep health is both conceptually and operationally a composite concept containing multiple domains of sleep. In line with this, high dependence and interaction across different domains of sleep health encourage a transition in sleep health research from categorical to dimensional approaches that integrate neuroscience and sleep health. Here, we seek to identify the covariance patterns between multiple sleep health domains and distributed intrinsic functional connectivity by applying a multivariate approach (partial least squares). This multivariate analysis reveals a composite sleep health dimension co-varying with connectivity patterns involving the attentional and thalamic networks and which appear relevant at the neuromolecular level. These findings are further replicated and generalized to several unseen independent datasets. Critically, the identified sleep-health related connectome shows diagnostic potential for insomnia disorder. These results together delineate a potential brain connectome biomarker for sleep health with high potential for clinical translation.
- Published
- 2023
- Full Text
- View/download PDF
21. Older Adult Tourism to Older Adult Sojourn: A New Discuss Based on the Life-Span Theory of Control
- Author
-
Liu Bin, Xu Lei, and Chen Hao
- Subjects
older adult sojourn ,older adult tourism ,life-span theory of control ,resource-willpower input ,Geography (General) ,G1-922 - Abstract
The autonomy and travel conditions for older adult tourists have significantly improved, leading to a diversification of their tourism activities. Among these, the concept of a free and comfortable sojourn has gained popularity. Despite the complex concept of older adult sojourns being established in related research, the concepts often overlap and are fragmented, leading to a disjointed understanding of the phenomenon. This study aims to incorporate the life-span theory of control and its optimization strategy framework from a life-span development perspective in older adults. By deeply connecting research on older adults with tourism research through life-span development thinking, we aim to explore methods of coordinating and analyzing older adult sojourns. This approach will allow us to systematically reshape existing conceptual knowledge. Based on the results of this coordinated analysis, we aim to gain a systematic understanding of older adult sojourns and propose future research directions. The study revealed that older adult tourism exhibits strategic traits consistent with the life-span theory of control, where resource allocation and willpower investment are crucial elements. This forms a resource-willpower investment framework that categorizes 16 different older adult tourism behavior patterns. Using this framework, by comparing the characteristics of older adult travel with the 16 classification results, the resource and willpower investment framework is focused on the amount of resources invested in the destination and the distance of the trip. This further refines the corresponding older adult travel patterns into four types: relatively high investment in travel to distant areas, relatively high investment in travel to nearby areas, relatively low investment in travel to distant areas, and relatively low investment in travel to nearby areas. The study reveals that the four categories represent varying lifestyle demands and participation limitations for older adults. Those who invest more and travel longer distances tend to face greater participation challenges, have fewer companions, require more from their destinations, and have limited choices. Conversely, those who invest less and travel shorter distances experience the opposite. The four categories of older adult travel display different scene transitions and state changes, each with unique participation challenges, social choices, and destination requirements. Overall, the categorization of older adult tourism types and the comprehensive analysis of older adult travel types constitute a process of knowledge creation. The research employs deductive methods for progressive exploration, building a comprehensive classification framework. This framework lays a cognitive foundation for future research and provides key directions. The innovative research approach, in conjunction with the life-span theory of control, provides a method for pattern analysis to understand ongoing tourism behaviors and phenomena that are constantly evolving and enriching. Older adult sojourn is one of the few forms of tourism that is notably age-friendly. The prospects for research and industrial development of this phenomenon are promising, but there is currently a lack of discussion about the phenomenon itself. Future research can build upon this initial understanding to further investigate behavioral characteristics, values related to aging, and local response needs. By examining behavior, subject, and space, a study can be conducted on behavior, motivation, space, and their interactive results, leading to more systematic findings and enhancing the practical value of the guidance.
- Published
- 2023
- Full Text
- View/download PDF
22. Advances in nonlinear metasurfaces for imaging, quantum, and sensing applications
- Author
-
Zheng Ze, Rocco Davide, Ren Hang, Sergaeva Olga, Zhang Yipei, Whaley K. Birgitta, Ying Cuifeng, de Ceglia Domenico, De-Angelis Constantino, Rahmani Mohsen, and Xu Lei
- Subjects
nonlinear metasurfaces ,nonlinear imaging ,spontaneous parametric down-conversion ,sensing ,Physics ,QC1-999 - Abstract
Metasurfaces, composed of artificial meta-atoms of subwavelength size, can support strong light–matter interaction based on multipolar resonances and plasmonics, hence offering the great capability of empowering nonlinear generation. Recently, owing to their ability to manipulate the amplitude and phase of the nonlinear emission in the subwavelength scale, metasurfaces have been recognized as ultra-compact, flat optical components for a vast range of applications, including nonlinear imaging, quantum light sources, and ultrasensitive sensing. This review focuses on the recent progress on nonlinear metasurfaces for those applications. The principles and advances of metasurfaces-based techniques for image generation, including image encoding, holography, and metalens, are investigated and presented. Additionally, the overview and development of spontaneous photon pair generation from metasurfaces are demonstrated and discussed, focusing on the aspects of photon pair generation rate and entanglement of photon pairs. The recent blossoming of the nonlinear metasurfaces field has triggered growing interest to explore its ability to efficiently up-convert infrared images of arbitrary objects to visible images and achieve spontaneous parametric down-conversion. This recently emerged direction holds promising potential for the next-generation technology in night-vision, quantum computing, and biosensing fields.
- Published
- 2023
- Full Text
- View/download PDF
23. Coagulation markers as independent predictors of prostate cancer aggressiveness: a retrospective cohort study
- Author
-
Xu Lei, Tengfei Zhang, Zhixuan Deng, Tao Jiang, Yang Hu, and Ning Yang
- Subjects
Medicine ,Science - Abstract
Abstract Coagulation system activation is commonly observed in tumor patients, including prostate cancer (PCa), with coagulation markers proposed as potential prognostic indicators for cancer severity. However, the correlation between these markers and clinicopathological features in PCa remains unclear. Thus, this study investigates the association between comprehensive coagulation markers and clinicopathological characteristics in PCa patients. A retrospective evaluation of 162 PCa patients diagnosed and categorized into low-intermediate-risk or high-risk groups based on clinical and pathological features was conducted. Coagulation markers, including fibrinogen (FIB), d-dimer (DD), activated partial thromboplastin time (APTT), prothrombin time (PT), prothrombin activity (PTA), thrombin time (TT), platelet count (PLT), and international normalized ratio (INR), were assessed. Univariate and multivariate logistic regression analyses were performed to determine associations with clinicopathological features. FIB and DD were confirmed as independent factors associated with high-risk PCa. Furthermore, FIB and DD levels showed significant positive correlations with clinical parameters, including PSA levels, ISUP grade, T stage, N stage, and M stage. Our findings suggest that FIB and DD hold promise as independent prognostic biomarkers for risk stratification in PCa. These coagulation markers may aid in assessing PCa severity and guiding personalized treatment strategies.
- Published
- 2023
- Full Text
- View/download PDF
24. A 2-year follow-up analysis of diabetic patients and high-risk groups in a community in Shanghai
- Author
-
YAO Youhua, XU Lei, WANG Shiping, and BAO Yong
- Subjects
diabetes ,high-risk population ,follow-up ,risk factor ,health education ,Medicine - Abstract
ObjectiveA high-risk group of diabetes in a community in Shanghai was followed up for 2 years. The level of blood glucose control was monitored, the incidence and risk factors of the high-risk group were analyzed, and the incidence and risk factors distribution in the community were studied. The results will provide a basis for the community to formulate strategies for early prevention and treatment of diabetes in Shanghai.MethodsA total of 580 subjects were collected, according to the criteria of high-risk groups of diabetes. Among them, 77 people whose blood glucose had reached the diagnostic criteria for diabetes entered the patient group, and the rest 503 people entered the high-risk group. Corresponding intervention methods such as outpatient follow-up and health education were given, and blood glucose monitoring was repeated at the 12th month and 24th month after enrollment. Blood glucose control, new-onset diabetes and the effect of intervention were analyzed.ResultsThe patients’ venous fasting blood glucose level at the 12th and 24th month was significantly lower than that at the baseline survey, and there was no significant change in body mass index (BMI) and waist circumference. Subjects in patient group were older and had a higher proportion of a history of impaired glycemic regulation, family history of diabetes, hypertension, and hyperlipidemia than those in high-risk group. In the high-risk group of 503 cases, 74 (14.7%) were new-onset diabetics during the follow-up period, A higher proportion of new-onset diabetics were male, BMI, a combined history of impaired glucose regulation and gestational diabetes history of gestational diabetes mellitus (women only) was a contributing factor to the onset of diabetes.ConclusionHigh-risk groups are more susceptible to diabetes; patients in the diabetes group have better control of fasting blood glucose levels during the 2-year follow-up period, and outpatient follow-up combined with comprehensive interventions helps diabetic patients to control blood glucose.
- Published
- 2023
- Full Text
- View/download PDF
25. Differences in attentional function between experienced mindfulness meditators and non-meditators
- Author
-
Xiaohui Luo, Jia Zhao, Dongfang Zhao, Li Wang, Yi Hou, Yong Liu, Jing Zeng, Hong Yuan, and Xu Lei
- Subjects
mindfulness ,meditation ,attention ,electroencephalography ,P2 ,P3 ,Psychiatry ,RC435-571 - Abstract
IntroductionAttentional enhancement has often been identified as the central cognitive mechanism underlying the benefits of mindfulness meditation. However, the extent to which this enhancement is observable in the neural processes underlying long-term meditation is unclear. This current study aimed to examine differences in attentional performance between meditators and controls (non-meditators) using a visual oddball task with concurrent electroencephalography (EEG) recordings.MethodsThirty-four participants were recruited, including 16 meditators and 18 healthy controls, who were non-meditators. The participants completed a visual oddball task, using visual stimuli, and EEG recording.ResultsSelf-reports revealed that meditators had higher mindful attention scores than did the control group. The behavioral results showed that the meditators demonstrated faster reaction times than the non-meditators did. Neural findings indicated a higher P2 amplitude in the meditators than in the controls. The meditators demonstrated a significantly higher P3 in the target trials than in the distractor trials, which was not observed in the controls. Additionally, the time-frequency analysis demonstrated that the delta and theta powers in the meditators were significantly higher than those in the controls.ConclusionsThe study suggests the meditators exhibited greater attentional performance than the controls did, as revealed by EEG and behavioral measures. This study extends previous research on the effects of mindfulness meditation on attention and adds to our understanding of the effects of long-term mindfulness meditation.
- Published
- 2024
- Full Text
- View/download PDF
26. CT-guided percutaneous microwave ablation combined with bone cement injection for the treatment of transverse metastases: A case report
- Author
-
Hu Hongtao, Xu Lei, Guo Xiang, Teng Haijun, and Liu Wenhua
- Subjects
metastatic tumor ,microwave ablation ,bone cement ,transverse process ,Medicine - Abstract
Metastatic diseases of the spine are becoming increasingly common with an aging population and improvements in systemic cancer therapies. Microwave and vertebroplasty are the mainstay modalities for treating painful spine metastases. Most early spinal metastases predominantly attack the adnexa, but there are few reports on its treatment. This report presents a case of a 56-year-old female who had experienced severe thoracic back pain for several days and was diagnosed with a metastatic tumor of the right transverse process of T7. Percutaneous microwave ablation in combination with bone cement injection was used to treat the metastatic tumor under CT guidance. The postoperative pain on the Visual Analogue Scale was 1/10, without nerve or vessel damage and bone cement leakage during the operation.
- Published
- 2023
- Full Text
- View/download PDF
27. Hierarchical fluctuation shapes a dynamic flow linked to states of consciousness
- Author
-
Ang Li, Haiyang Liu, Xu Lei, Yini He, Qian Wu, Yan Yan, Xin Zhou, Xiaohan Tian, Yingjie Peng, Shangzheng Huang, Kaixin Li, Meng Wang, Yuqing Sun, Hao Yan, Cheng Zhang, Sheng He, Ruquan Han, Xiaoqun Wang, and Bing Liu
- Subjects
Science - Abstract
Abstract Consciousness arises from the spatiotemporal neural dynamics, however, its relationship with neural flexibility and regional specialization remains elusive. We identified a consciousness-related signature marked by shifting spontaneous fluctuations along a unimodal-transmodal cortical axis. This simple signature is sensitive to altered states of consciousness in single individuals, exhibiting abnormal elevation under psychedelics and in psychosis. The hierarchical dynamic reflects brain state changes in global integration and connectome diversity under task-free conditions. Quasi-periodic pattern detection revealed that hierarchical heterogeneity as spatiotemporally propagating waves linking to arousal. A similar pattern can be observed in macaque electrocorticography. Furthermore, the spatial distribution of principal cortical gradient preferentially recapitulated the genetic transcription levels of the histaminergic system and that of the functional connectome mapping of the tuberomammillary nucleus, which promotes wakefulness. Combining behavioral, neuroimaging, electrophysiological, and transcriptomic evidence, we propose that global consciousness is supported by efficient hierarchical processing constrained along a low-dimensional macroscale gradient.
- Published
- 2023
- Full Text
- View/download PDF
28. Dynamic Load Performance of a Face Gear Drive in a Spent Fuel Reactor
- Author
-
Guo Mingchao, Zhang Ju, Xu Lei, and Kan Chen
- Subjects
Spent fuel ,Reactor ,Face gear drive ,Meshing stiffness ,Dynamic load coefficient ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
The main transmission system in a spent fuel reactor is a face gear drive, which works in concentrated nitric acid with high-temperature, and requires not to be damaged under earthquake. To design its strength reasonably, the dynamic performance of the face gear drive is studied. Its meshing principle and characteristics are briefly elaborated. The dynamic model of the face gear drive is established based on the centralized mass method.The influence of factors such as manufacturing errors and misalignments, time-varying meshing stiffness, corrosion on tooth surfaces, earthquakes on the dynamic performance are taken into consideration to deduce the differential equations of the face gear drive. Runge-Kutta method is applied to solve the differential equation, the dynamic loads under excitations of misalignment, earthquake and corrosion are obtained, and the influence law of these excitations on the dynamic load coefficient is further analyzed. The corrosion and earthquake are the key factors that cause significant increase of dynamic load coefficients, the dynamic load caused by the combined action of the considered various factors is less than twice the driving load.
- Published
- 2023
- Full Text
- View/download PDF
29. Significant elevated CXCL14 and decreased IL-39 levels in patients with tuberculosis
- Author
-
Ding Min, Wang Hong-xu, Gao Si-jia, Lai Xiao-fei, Li An-long, Bao Jia-jia, Hosyanto Felycia-Fernanda, and Xu Lei
- Subjects
il-39 ,cxcl14 ,tuberculosis ,bcg ,cytokine ,biomarker ,Biology (General) ,QH301-705.5 - Abstract
To explore the serum levels of IL-39, CXCL14, and IL-19 in patients with tuberculosis (TB) along with their clinical significances and their concentration changes in macrophages after Bacille Calmette-Guérin vaccine (BCG) or Mycobacterium tuberculosis (M. tb) H37Rv stimulation in vitro. The serum levels of IL-39, CXCL14, and IL-19 of 38 TB patients, and 20 healthy staff members were measured by enzyme-linked immunosorbent assay. Moreover, the levels of IL-19, CXCL14, and IL-39 in cultured THP-1 macrophages were detected at 12, 24, and 48 h after stimulation with BCG or M. tb H37Rv strains. It was found the serum level of IL-39 was significantly reduced and CXCL14 was remarkably elevated in TB patients. In vitro, at 48 h after stimulation, IL-39 level of cultured THP-1 macrophages in the H37Rv group was significantly lower than that in the BCG and control groups, and the CXCL14 level of cultured THP-1 macrophages in the H37Rv stimulation group was remarkably higher than that in the control group. Therefore, IL-39 and CXCL14 may be involved the pathogenesis of TB, and serum IL-39 and CXCL14 could potentially serve as a new biomarker of TB.
- Published
- 2023
- Full Text
- View/download PDF
30. Quasi-bound states in the continuum with a stable resonance wavelength in dimer dielectric metasurfaces
- Author
-
You Shaojun, Zhou Mimi, Xu Lei, Chen Deliang, Fan Menghui, Huang Jing, Ma Wenbin, Luo Shengyun, Rahmani Mohsen, Zhou Chaobiao, Miroshnichenko Andrey E., and Huang Lujun
- Subjects
all-dielectric metasurfaces ,bound states in the continuum ,stable resonance wavelengths ,Physics ,QC1-999 - Abstract
Symmetry-protected bound states in the continuum (SP-BICs) are one of the most intensively studied BICs. Typically, SP-BICs must be converted into quasi-BICs (QBICs) by breaking the unit cell’s symmetry so that they can be accessed by the external excitation. The symmetry-broken usually results in a varied resonance wavelength of QBICs which are also highly sensitive to the asymmetry parameters. In this work, we demonstrate that QBICs with a stable resonance wavelength can be realized by breaking translational symmetry in an all-dielectric metasurface. The unit cell of metasurface is made of a silicon nanodisk dimer. The Q-factor of QBICs is precisely tuned by changing the interspacing of two nanodisks while their resonance wavelength is quite stable against the interspacing. We also find that such BICs show weak dependence on the shape of the nanodisk. Multiple decompositions indicate that the toroidal dipole dominates this type of QBIC. The resonance wavelengths of QBICs can be tuned only by changing either the lattice constants or the radius of nanodisk. Finally, we present experimental demonstrations on such a QBIC with a stable resonance wavelength. The highest measured Q-factor of QBICs is >3000. Our results may find promising applications in enhancing light–matter interaction.
- Published
- 2023
- Full Text
- View/download PDF
31. Geochemical Characteristics and Environmental Risk Assessment of Heavy Metals in Weathering Profiles of Alkali-enriched Porphyry in Central Yunnan
- Author
-
XU Lei, ZHAO Mengsheng, XU Jie, CHENG Yanxun, QU Qiang, CHEN Weizhi, ZHANG Ya, WANG Haoyu, BA Yong, WEN Fangping, and QIAN Kun
- Subjects
alkali-enriched porphyry ,weathering ,heavy metals ,inductively coupled plasma-mass spectrometry/optical emission spectrometryy ,atomic fluorescence spectrometry ,x-ray fluorescence spectrometry ,geochemical behavior characteristics ,environmental risk assessment ,Geology ,QE1-996.5 ,Ecology ,QH540-549.5 - Abstract
BACKGROUND The contents of many heavy metals in soil in many areas of southwest China are much higher than the national soil background value, and related studies show that most heavy metals in soil are in a state of “high background and low activity”, which is closely related to the special geological process in the area. Most scholars have concentrated more on the weathering process and post-weathering heavy metals of granite, basalt, carbonate rocks and other geological bodies with high background value of heavy metals in southwest China. However, alkali-enriched porphyry also has the characteristics of high background value of heavy metals, and the geochemical behavior characteristics of heavy metals in the weathering process of alkali-enriched porphyry are less studied. The ecological and environmental effects of heavy metal element migration and transformation during weathering are still unclear. There is a large-scale alkali-enriched porphyry belt located in southwest China. Most of the alkali-enriched porphyry areas have precious metals such as gold and silver, and polymetallic deposits such as copper, lead and zinc. Therefore, soil in alkali-enriched porphyry areas usually has the characteristic of high background value of heavy metals. OBJECTIVES For identifying geochemical characteristics of heavy metal elements and a series of ecological and environmental problems during the soil-forming process of alkali-enriched porphyry, to provide a scientific basis for the prevention and control of heavy metal pollution in alkali-enriched porphyry areas and rational planning of agricultural planting. METHODS For sufficient hydrothermal conditions and strong soil-forming in Yunnan Province, a rock weathering profile of Yao’an alkali-enriched porphyry in central Yunnan Province was selected as the research object. The contents of As, Cd, Cr, Cu, Hg, Ni, Pb, Zn, Al2O3, TFe2O3, CaO, Na2O, K2O, MgO, SiO2, organic carbon and pH in rock/soil samples were determined by inductively coupled plasma-mass spectrometry/optimal emission spectrometry (ICP-MS/OES), atomic fluorescence spectrometry (AFS), X-ray fluorescence spectrometry (XRF) and volumetric method. Multivariate statistics method and mass migration coefficient were used to study the distribution characteristics, migration and enrichment rules of heavy metal elements in the weathering profile, as well as the factors affecting the migration and enrichment of heavy metals. RESULTS Based on the analysis of the content and distribution characteristics of eight heavy metals in the weathering profile of Yao’an alkali-enriched porphyry, the migration and enrichment mechanism of heavy metals during the weathering process was identified, and the environmental risk assessment of the surface soil in the area was carried out. (1) In the weathering profile, all the weathering strata have the same source as the bedrock material, and there is no exogenous addition. Different degrees of desiliconization and aluminum-iron enrichment occur in the whole weathering process, especially in the surface layer. In the bottom-up evolution process, all of the heavy metal elements except Cd show an overall trend of increasing content. As, Cr, Cu, Hg and Ni are enriched to different degrees during weathering, while Cd, Pb and Zn are leaching out. The order of heavy metal migration capacity from strong to weak is Cd>Zn>Pb>Hg>Cu>As>Ni>Cr. As, Cr, Cu, and Hg have similar geochemical behavior, as do Cd, Pb, and Zn. (2) Cd, Pb and Zn occur mainly in feldspar minerals and lead-zinc metallic minerals and exhibit the characteristics of migration and leaching under acidic and strong leaching conditions. Although the bedrock is obviously deficient in Cu, Cr, Ni and Hg, it is eventually enrichedin-situ in clay minerals and Al and Fe oxides/hydroxides with weathering due to its own chemical properties and the effect of desilication to enrich aluminum and iron. The enrichment of As is mainly controlled by aluminum-Fe enrichment, and the strong aluminum-Fe enrichment in the study area results in the in-situ secondary enrichment of As. (3) The soil ecological environment in the study area may be polluted by As and Pb due to the high content of Pb in the bedrock and the effect of aluminum-iron enrichment. CONCLUSIONS The risk of As and Pb pollution may exist in the soil ecological environment of the study area, and a large amount of Pb leaching may migrate into the Dragonling River with surface runoff. It is necessary to strengthen the monitoring of heavy metals such as As and Pb in the overlying soil of alkali-enriched porphyry and heavy metals such as Pb and Zn in the rivers around alkali-enriched porphyry so as to ensure ecological safety.
- Published
- 2023
- Full Text
- View/download PDF
32. A New Strategy: Remaining Useful Life Prediction of Wind Power Bearings Based on Deep Learning under Data Missing Conditions
- Author
-
Xuejun Li, Xu Lei, Lingli Jiang, Tongguang Yang, and Zhenyu Ge
- Subjects
wind power bearing ,remaining useful life prediction ,data missing ,average similarity ,Mathematics ,QA1-939 - Abstract
With its formidable nonlinear mapping capabilities, deep learning has been widely applied in bearing remaining useful life (RUL) prediction. Given that equipment in actual work is subject to numerous disturbances, the collected data tends to exhibit random missing values. Furthermore, due to the dynamic nature of wind turbine environments, LSTM models relying on manually set parameters exhibit certain limitations. Considering these factors can lead to issues with the accuracy of predictive models when forecasting the remaining useful life (RUL) of wind turbine bearings. In light of this issue, a novel strategy for predicting the remaining life of wind turbine bearings under data scarcity conditions is proposed. Firstly, the average similarity (AS) is introduced to reconstruct the discriminator of the Generative Adversarial Imputation Nets (GAIN), and the adversarial process between the generative module and the discriminant is strengthened. Based on this, the dung beetle algorithm (DBO) is used to optimize multiple parameters of the long-term and short-term memory network (LSTM), and the complete data after filling is used as the input data of the optimized LSTM to realize the prediction of the remaining life of the wind power bearing. The effectiveness of the proposed method is verified by the full-life data test of bearings. The results show that, under the condition of missing data, the new strategy of AS-GAIN-LSTM is used to predict the RUL of wind turbine bearings, which has a more stable prediction performance.
- Published
- 2024
- Full Text
- View/download PDF
33. Kinetics of phenol hydroxylation reaction of open mesoporous TS-1 with high backbone titanium content
- Author
-
Wang Shuai, Yang Zhenyuan, Xu Lei, Wang Na, Mu Shenglong, and Jiao Yilai
- Subjects
ts-1 ,aged dry gel domain-limited transformation ,phenol hydroxylation ,intrinsic kinetics ,68t05 ,Mathematics ,QA1-939 - Abstract
High skeletal titanium content, open mesoporous TS-1 titanosilica molecular sieves with more accessible active centres exhibit higher catalytic activity, target product selectivity and resistance to coking deactivation in green catalytic oxidation reactions using hydrogen peroxide as oxidant. In this paper, TS-1 titania-silica molecular sieves without anatase, with the highest theoretical skeletal titanium content (2.0 wt%) and open mesopores (mesopore volume 0.71 cm3/g) were synthesised based on the ageing dry gel limited domain conversion method invented in previous research work. The intrinsic kinetics of the catalytic reaction of phenol with hydrogen peroxide for direct hydroxylation of benzenes was investigated. The effects of stirring rate, phenol concentration, hydrogen peroxide concentration, catalyst dosage and reaction temperature on the initial conversion rate of phenol were investigated, and the experimental data were fitted with a power function equation to obtain the intrinsic kinetic equation of the catalyst (r=2.98×106 exp (−56.43×103RT)c1.07(Phenol)c0.10(H2O2))\left( {{\rm{r}} = 2.98 \times {{10}^6}\,\exp \,\left( { - {{56.43 \times {{10}^3}} \over {RT}}} \right){c^{1.07}}\left( {{\rm{Phenol}}} \right){c^{0.10}}\left( {{{\rm{H}}_2}{{\rm{O}}_2}} \right)} \right). Under the condition of eliminating the effect of internal and external diffusion, the reaction was 1.07 and 0.10 for phenol and hydrogen peroxide, respectively, with a reaction activation energy of 56.43 kJ/mol. This study provides a theoretical basis for the reactor and process design of hydroxylation of phenol to benzenediol based on this new catalyst.
- Published
- 2024
- Full Text
- View/download PDF
34. Research on the Application of Knowledge Graph in Demand-Side Flexible Resource Profiling and Aggregation Techniques
- Author
-
Yang Chao, Wang Libin, Feng Lida, Xu Lei, Yao Tao, Lv Yuntong, and Lei Shuya
- Subjects
demand side ,flexible resources ,aggregation techniques ,knowledge graphs ,68t05 ,Mathematics ,QA1-939 - Abstract
This paper commences by assessing the current landscape of power system development, focusing on the theory, principles, and structures of demand-side flexible resources and their aggregation technology. Utilizing network crawler technology within a knowledge graph framework, the research data pertinent to demand-side flexible resources and aggregation technology are extracted. These data undergo a meticulous cleaning process before being stored, culminating in the development of a knowledge graph tailored to the imaging and technology of demand-side flexible resources. The findings reveal a response rate of 7.25% ± 1.15%, with an uncertainty interval of 2.33%. Variations in air-conditioning load states appear to exert minimal impact on the response time lag. Following the issuance of a response signal, all systems can rapidly initiate appropriate response actions, demonstrating an uncertainty interval of approximately 52s±11s and 22s. The duration of the responses averages around 75s±11s, with an uncertainty interval of about 30s. This study fulfills the power system criteria for standards of demand-side flexible resources and augments the competitiveness of China’s power market.
- Published
- 2024
- Full Text
- View/download PDF
35. Study on the Role of Public Sector Human Resource Management in Educational Management Reforms
- Author
-
Xu Lei
- Subjects
factor analysis method ,factor loadings ,resource allocation ,education management ,68t05 ,Mathematics ,QA1-939 - Abstract
The principles and methods of human resource management have been introduced into the field of education for some time, but the analysis of the current state of research, specifically on educational management, is still insufficient. The first part of this paper analyzes the measures that are related to human resource management in education management reform in each sector and further investigates the factor analysis method in the public sector human resource management system. By constructing the factor analysis model and factor calculation method, we can provide an algorithmic basis for studying the role of public sector human resource management in education management reform. The article utilizes the factor analysis method to conduct an empirical study by using the educational resources of different schools in 11 cities of Province A as test objects. According to the study, the first principal component has seven-factor loadings that are higher than 0.72, which indicates that all seven factors have a positive impact on the allocation efficiency of higher vocational education. The second principal component has four-factor loadings greater than 0.80, suggesting that all four factors have a positive effect on the allocation efficiency output of higher vocational education. From the sample data of the school education resource allocation status of each city, it can be obtained that the school education resource allocation status of city A is the most favorable, with the highest overall score of 43,153.1, followed by city B and city D, with 25,431.9 and 12,136.4, respectively. This indicates that the education resource allocation effect of these three cities is better and belongs to the upstream level in province Z.
- Published
- 2024
- Full Text
- View/download PDF
36. Spa therapy improves sleep quality: evidence from questionnaire and actigraphy
- Author
-
Suchen Yao, Jie Wang, and Xu Lei
- Subjects
insomnia ,hot spring ,passive body heating ,actigraphy ,pre-sleep thoughts inventory ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Background Sleep-wake rhythm is highly correlated with core body temperature, and bathing in the hot spring can effectively manipulate core body temperature to improve sleep quality. However, there is still a lack of experimental research on the influencing factors of utilizing hot spring facilities to positively affect sleep. Methods In this study, we aimed to explore the factors improving sleep quality via hot spring bathing in terms of both subjective (self-rating scales) and objective (actigraphy) measures, 33 insomniacs were recruited and randomly divided into the afternoon (AG) and evening bathing groups (EG). Results The results showed that after the intervention, subjective sleep quality was improved significantly in both groups, and the evening bathing group had a better performance. In contrast, neither group had a significant change in objective sleep measures. Moreover, we found that hot spring spa therapy is particularly effective in reducing pre-sleep thoughts inventory and shortening sleep onset latency, and it is more applicable to people with difficulty falling asleep. Conclusion This study identified the timing and individual's behaviour traits as the important factors, and these formed practical guidance for sleep improvement by spa therapy.
- Published
- 2023
- Full Text
- View/download PDF
37. Sleep loss and lack of social interaction: a summary interview
- Author
-
Yiqi Mi and Xu Lei
- Subjects
sleep deprivation ,social relationships ,social pain ,loneliness ,brain networks ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Sleep loss is popular in modern society, and this health problem may further lead to social dysfunctions. In this article, we present some interesting behavioral and fMRI studies in the field of sleep and social functions. In light of these studies, we provide a dynamic framework for understanding the relationship between sleep loss and social interaction. In this framework, four sequential stages construct a life circle of interaction. The effects of sleep loss have distinct functions in each stage and correspond to different brain networks. These functions include the desire for social interaction, social withdrawal, subjective perceptions of social relationships, and loneliness. More importantly, we identify the core behavioral factors may be sleepiness, social-emotional processing, memory control, and rumination. For the brain networks, default mode network, negative affective network, inhibitory control network, and near-space networks may contribute to the relation between sleep loss and social interaction. In the future, experiments based on ecological sampling, and tracking studies based on the life cycle of interaction may be helpful for our understanding of this framework. The applications of some new technologies such as brain stimulation and neural feedback can be taken at different stages of social interactions.
- Published
- 2023
- Full Text
- View/download PDF
38. Takeoff performance analysis and optimization of civil aircraft at plateau airport
- Author
-
WANG Tianbo, ZHAO Tao, XU Lei, LIU Chao, and DING Yaxiu
- Subjects
civil aircraft ,takeoff performance ,plateau airport operation ,one engine inoperative ,Motor vehicles. Aeronautics. Astronautics ,TL1-4050 - Abstract
In the operation of civil aircraft at plateau airport, the climbing gradient is required to be high, and the load loss is serious.Therefore, it is of great significance to optimize the takeoff performance and increase the takeoff weight in terms of economic benefits.In this paper, based on theoretical analysis, the takeoff performance is optimized under the premise of meeting the airworthiness requirements by reducing the flap deflection or using the improved climb method, and the takeoff distances, acceleration stop distances, and takeoff weights of different flap configurations and different climb methods are calculated and analyzed.The results show that the effective optimization can significantly improve the takeoff weight and performance, also yield good economic returns.
- Published
- 2023
- Full Text
- View/download PDF
39. Application Research of Mathematica Software in Calculus Teaching
- Author
-
Xu Lei and Chen Kan
- Subjects
mathematica ,symbolic computation ,calculus teaching ,numerical computation ,68n30 ,Mathematics ,QA1-939 - Abstract
Under the background of teaching in the new era, image recognition, operation, and processing of experimental data are still the focus of calculus teaching. Mathematica has powerful functions as mathematical software and was developed by Wolfram Research. Aiming at the complex symbols and data operation problems in many fields, the software flexibly combines mathematics branches such as geometry and algebra, dramatically simplifying the operation process. This paper takes Mathematica’s existing mathematical software as a reference to discuss whether the addition of such software helps improve the effectiveness of daily teaching. The study found that using this software can stimulate students’ interest and enhance the quality of education.
- Published
- 2023
- Full Text
- View/download PDF
40. Zirconium-modified attapulgite was used for removing of Cr(vi) in aqueous solution
- Author
-
Liu Yani, Xu Lei, Wang Qingyun, Zou Tong, Cao Cheng, Fang Qiqi, Zhang Nan, and Wang Yongcheng
- Subjects
attapulgite ,adsorption ,chromium ions ,dft calculation ,Chemistry ,QD1-999 - Published
- 2022
- Full Text
- View/download PDF
41. Enhanced rich club connectivity in mild or moderate depression after nonpharmacological treatment: A preliminary study
- Author
-
Zhiliang Long, Danni Chen, and Xu Lei
- Subjects
depression ,functional MRI ,nonpharmacological treatment ,rich club ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Abstract Introduction It has been suggested that the rich club organization in major depressive disorder (MDD) was altered. However, it remained unclear whether the rich club organization could be served as a biomarker that predicted the improvement of clinical symptoms in MDD. Methods The current study included 29 mild or moderate patients with MDD, who were grouped into a treatment group (receiving cognitive behavioral therapy or real‐time fMRI feedback treatment) and a no‐treatment group. Resting‐state MRI scans were obtained for all participants. Graph theory was employed to investigate the treatment‐related changes in network properties and rich club organization. Results We found that patients in the treatment group had decreased depressive symptom scores and enhanced rich club connectivity following the nonpharmacological treatment. Moreover, the changes in rich club connectivity were significantly correlated with the changes in depressive symptom scores. In addition, the nonpharmacological treatment on patients with MDD increased functional connectivity mainly among the salience network, default mode network, frontoparietal network, and subcortical network. Patients in the no‐treatment group did not show significant changes in depressive symptom scores and rich club organization. Conclusions Those results suggested that the remission of depressive symptoms after nonpharmacological treatment in MDD patients was associated with the increased efficiency of global information processing.
- Published
- 2023
- Full Text
- View/download PDF
42. Partial cystectomy for bladder squamous cell carcinoma with a 10-year follow-up: a case report
- Author
-
Na Yin, Wei Zhao, Tao He, Tingchao Li, Xu Lei, Hao He, Zongmin Long, and Yan Wang
- Subjects
partial resection ,urinary bladder neoplasms ,carcinoma ,squamous cell ,diagnosis ,pathology ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Squamous cell carcinoma (SCC) of the bladder is a rare malignancy of the urinary system. It is prone to invasion and metastasis in the early stage and has a poor prognosis. This case reports a 65-year-old female patient with SCC of the bladder who was free of disease recurrence and metastasis 10 years after partial cystectomy (PC) combined with left ureteral reimplantation. The treatment plan and admission of this patient were retrospectively analyzed in order to provide some reference significance for the treatment plan for the SCC of the bladder.
- Published
- 2023
- Full Text
- View/download PDF
43. A test-retest resting, and cognitive state EEG dataset during multiple subject-driven states
- Author
-
Yulin Wang, Wei Duan, Debo Dong, Lihong Ding, and Xu Lei
- Subjects
Science - Abstract
Measurement(s) resting and cogntive state EEG Technology Type(s) electroencephalography (EEG) Factor Type(s) session Sample Characteristic - Organism human being
- Published
- 2022
- Full Text
- View/download PDF
44. Inflammation-related research within the field of bladder cancer: a bibliometric analysis
- Author
-
Zhixuan Deng, Ning Tang, Wanyan Xiong, Xu Lei, Tengfei Zhang, and Ning Yang
- Subjects
bladder cancer ,inflammation ,bibliometrics ,CiteSpace ,VOSviewer ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
BackgroundIn recent years, the link between inflammation and bladder cancer(BC) has received much attention. However, there were no relevant bibliometric studies to analyze the inflammation-related research within this field of BC.MethodsWe selected Web of Science Core Collection (WOSCC) as the data source to obtain articles and reviews on inflammation-related research within te field of BC from WOSCC’s inception to October 10, 2022. The collected data were meticulously and manually screened, after which we used VOSviewer, CiteSpace, Biblioshiny and an online analysis platform (https://bibliometric.com/) to perform bibliometric analysis on the data and visualize the results.ResultsA total of 4301 papers related to inflammation-related research within this field of BC were included in this study.The number of publications has steadily increased over the last decades (R²=0.9021). The top contributing country was the United States, O’Donnell, Michael A was the most published authors, the leading contributing institution was the University of Texas, and the leading contributing journal was JOURNAL OF UROLOGY. The keywords co-occurrence analysis indicated that “immunotherapy,” “inflammation-related biomarkers,” and “tumor microenvironment” were the hot spots and frontiers of research in this field.ConclusionThis study clarifies the contribution of countries, institutions, authors, and journals in inflammation-related research within this field of BC through a bibliometric approach and identifies research hotspots and frontiers in the field. Notably, these findings can help researchers to understand more clearly the relationship between inflammation and BC.
- Published
- 2023
- Full Text
- View/download PDF
45. Can daily actigraphic profiles distinguish between different mood states in inpatients with bipolar disorder? An observational study
- Author
-
Yinlin Zhang, Xinyi Deng, Xueqian Wang, Huirong Luo, Xu Lei, and Qinghua Luo
- Subjects
bipolar disorder ,actigraphy ,motor activity ,Mania ,depression ,mixed-state ,Psychiatry ,RC435-571 - Abstract
BackgroundCriterion A changes for bipolar disorder (BD) in the Diagnostic and Statistical Manual of Mental Disorders–Fifth Edition yield new difficulties in diagnosis. Actigraphy has been used to capture the activity features of patients with BD. However, it remains unclear whether long-term actigraphic data could distinguish between different mood states in hospitalized patients with BD.MethodsIn this observational study, 30 hospitalized patients with BD were included. Wrist-worn actigraphs were used to monitor motor activity. The patients were divided into bipolar disorder–depression (BD-D), bipolar disorder–mania (BD-M), and bipolar disorder–mixed state (BD-MS) groups. Motor activity differences were estimated using non-parametric analyses between and within the three groups.ResultsThe mean 24 h activity level differed between the groups. In the between-group analysis, the intra-individual fluctuation and minute-to-minute variability in the morning and the mean activity level and minute-to-minute variability in the evening significantly differed between the BD-M and BD-MS groups. In the within-group analysis, the BD-M group showed a disrupted rhythm and reduced activity complexity at night. Both the BD-D and BD-MS groups demonstrated significant differences between several parameters obtained in the morning and evening.ConclusionThe mean activity levels during the relatively long monitoring period and the intra-day variation within the groups could reflect the differences in motor activity. Sustained activity monitoring may clarify the emotional states and provide information for clinical diagnosis.
- Published
- 2023
- Full Text
- View/download PDF
46. Microstructure and refinement mechanism of Al–5Ti–1B alloys
- Author
-
LI Yang, GUO Xu-qiang, XU Lei, LI Chang-yun, and LIU Xiao-fei
- Subjects
hot extrusion ,grain refiner ,al–ti–b alloys ,powder metallurgy ,refinement mechanism ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Two kinds of Al–5Ti–1B alloys were prepared by powder mixing + hot extrusion and powder mixing + gas atomization + hot extrusion, respectively. The microstructures of the Al–5Ti–1B alloys prepared by two kinds of processes were studied, and the grain refinement properties were assessed. The results show that, the TiB2 particles can be uniformly distributed and the growth of TiAl3 phase can be inhibited by these two kinds of processes. The Al–5Ti–1B alloys with the mass fraction of 0.2% are added to the melt of 7050 aluminum alloys. The grain refinement effect of the Al–5Ti–1B alloys prepared by powder mixing + hot extrusion is not obvious, and the grain size of 7050 aluminum alloys is still up to 1400 μm. The grain refinement effect of the Al–5Ti–1B alloys prepared by powder mixing+ gas atomization + hot extrusion is very good, the average grain size of 7050 aluminum alloys is only 176 μm. According to this experimental phenomenon, a new explanation for the grain refinement and double nucleation mechanism of the Al–Ti–B alloys is proposed.
- Published
- 2022
- Full Text
- View/download PDF
47. Preparation of the micro-size flake silver powders by using a micro-jet reactor
- Author
-
Li Jun, Li Na, Wan Xiaoxi, Tian Shihong, Liu Jianhua, Xu Lei, Wang Qin, and Ju Shaohua
- Subjects
micro-jet reactor ,flake silver powder ,micro-size ,sulfuric acid ,lauric acid ,Chemistry ,QD1-999 - Abstract
The micro-size flake silver powders were prepared through wet-chemical reduction method by using a micro-jet reactor. Herein ascorbic acid was used as a reducing agent, and sulfuric acid was used as a stabilizer. And the lauric acid was used as a dispersing agent to prevent particles’ agglomeration. The micro-jet reactor collides the two solutions together and uniformly mixes outside the reactor, to avoid the problem of clogging in the microchannel. The effects of dispersant addition and micro-jet flow rate on the morphology, particle size, and other parameters of silver powder is investigated in the present work. Interestingly, the addition of dispersant agent and stabilizer have a significant impact on the morphology and parameter of the silver particles. Under the conditions of micro-jet flow rate of 50 mL·min−1, sulfuric acid addition amount of 2%, and lauric acid addition amount of 0.8% by the weight of silver nitrate, a kind of flake silver powders with 4.40–4.70 μm can be prepared. The volume resistivity of the silver paste prepared from the obtained flake silver powders is in the range of 1.4–1.6 × 10−4 Ω·cm−1, which meets the application test requirements of conductive silver paste.
- Published
- 2022
- Full Text
- View/download PDF
48. Buyuan decoction inhibits autophagy in a rat model of chronic obstructive pulmonary disease
- Author
-
Huang Chunyan, Li Shaofeng, Xu Chao, Song Wenlong, Xu Lei, Lan Zhihui, and Liu Liangji
- Subjects
buyuan decoction ,chronic obstructive pulmonary disease (copd) ,autophagy ,pi3k pathway ,lipopolysaccharide (lps) ,Biology (General) ,QH301-705.5 - Abstract
Efforts have been made to find a better therapeutic approach with fewer side effects in treating chronic obstructive pulmonary disease (COPD). This study investigated the effect of Buyuan decoction (BYD) on autophagy in COPD rats. An experimental model with Sprague-Dawley rats was established by lipopolysaccharide (LPS) injection and cigarette smoke exposure. Rats were randomly allocated into blank control (normal control), experimental model, low-dose BYD (8.0 g/kg/day), medium-dose BYD (16.0 g/kg/day), high-dose BYD (32.0 g/kg/day) and 3-MA (methyladenine) groups (6 rats/group). Cell and tissue morphology were observed using hematoxylin and eosin staining. Autophagic vesicles were examined with a transmission electron microscope. Protein expression of LC3-II/I, BNIP- 1, ATG7, p62, PI3K and p-PI3K in lung tissue was detected by Western blotting. Compared with the experimental model group, the inflammatory infiltrate in lung tissue was reduced, the nuclei of the pulmonary epithelial cells were restored to normal, and the expression of LC3, BNIP1, ATG7 and p-PI3K was significantly downregulated, while p62 expression was significantly upregulated after treatment with the BYD. The effect was most significant in the low-dose BYD group (P
- Published
- 2022
- Full Text
- View/download PDF
49. Study on observation system of seismic forward prospecting in tunnel: A case on tailrace tunnel of Wudongde hydropower station
- Author
-
Yang Senlin, Cao Hongyi, Zhang Yi, Chen Lei, Xu Xinji, Song Jie, and Xu Lei
- Subjects
Geology ,QE1-996.5 - Abstract
Seismic method is a major approach for detecting the seismic geological features ahead of the tunnel, understanding the distribution of unfavorable geology, and ensuring the safety of tunnel construction. Observation system is the key for seismic detection, many studies have been conducted to optimize the observation system; however, most of them focused on the surface seismic investigation and numerical simulation rather than in tunnel field environment (limited aperture and full space environment). How to obtain better wavefield information with limited observation aperture is a great challenge. In this study numerical simulation and instrumental techniques (GPR, DC, etc.) were implemented to further check the result of seismic detection at the 1# tailrace tunnel at the Wudongde hydropower station. In the field case, observation detectors were arranged spatially in the tunnel and source points were placed in four ways: linearly along a single side, on the tunnel face, in front of the detectors, and behind the detectors. Then, after data acquisition, the data processing is conducted to carry out the migration results. The imaging results indicate that the observation system with sources and detectors in liner arrangement (with equal interval) helps to suppress artifacts, further supporting the advantages of spatial observation system with liner observation line (detectors). Moreover, the study provides suggestions for geological prospecting in similar tunnel projects.
- Published
- 2022
- Full Text
- View/download PDF
50. RESEARCH ON POST-PROCESSING METHOD OF CONTINUUM STRUCTURE TOPOLOGY OPTIMIZATION BASED ON VARIABLE DENSITY METHOD
- Author
-
ZHANG GuoFeng, XU Lei, WANG Xin, and XIAO NaiXin
- Subjects
Continuum ,Variable density method ,Post-processing ,Curve fitting ,Mechanical engineering and machinery ,TJ1-1570 ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
The variable density method has become an effective method to solve the topology optimization problem of continuum structure due to its advantages such as few design variables and high efficiency. Aiming at the problem of the gray unit and sawtooth boundary in the optimization process of the variable density method, a post-processing method of variable density method for continuum topology optimization is proposed in this paper. The topology optimization model is binarized and the sawtooth shape boundary line is extracted, and the target discrete corner point set is obtained, used as the sample point for curve fitting to obtain the optimized structure with smooth boundary. Experimental results show that this method effectively avoids the zigzag boundary and intermediate density of the optimization result, and improves the manufacturability of the optimization result under the premise of ensuring that the structural performance is within the allowable range.
- Published
- 2022
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.