90 results on '"Chen, Lijun"'
Search Results
2. Atrial Septal Defect Detection in Children Based on Ultrasound Video Using Multiple Instances Learning
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Liu, Yiman, Huang, Qiming, Han, Xiaoxiang, Liang, Tongtong, Zhang, Zhifang, Chen, Lijun, Wang, Jinfeng, Stefanidis, Angelos, Su, Jionglong, Chen, Jiangang, Li, Qingli, and Zhang, Yuqi
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FOS: Computer and information sciences ,Computer Science - Machine Learning ,Computer Vision and Pattern Recognition (cs.CV) ,Image and Video Processing (eess.IV) ,Computer Science - Computer Vision and Pattern Recognition ,FOS: Electrical engineering, electronic engineering, information engineering ,Electrical Engineering and Systems Science - Image and Video Processing ,Machine Learning (cs.LG) - Abstract
Purpose: Congenital heart defect (CHD) is the most common birth defect. Thoracic echocardiography (TTE) can provide sufficient cardiac structure information, evaluate hemodynamics and cardiac function, and is an effective method for atrial septal defect (ASD) examination. This paper aims to study a deep learning method based on cardiac ultrasound video to assist in ASD diagnosis. Materials and methods: We select two standard views of the atrial septum (subAS) and low parasternal four-compartment view (LPS4C) as the two views to identify ASD. We enlist data from 300 children patients as part of a double-blind experiment for five-fold cross-validation to verify the performance of our model. In addition, data from 30 children patients (15 positives and 15 negatives) are collected for clinician testing and compared to our model test results (these 30 samples do not participate in model training). We propose an echocardiography video-based atrial septal defect diagnosis system. In our model, we present a block random selection, maximal agreement decision and frame sampling strategy for training and testing respectively, resNet18 and r3D networks are used to extract the frame features and aggregate them to build a rich video-level representation. Results: We validate our model using our private dataset by five-cross validation. For ASD detection, we achieve 89.33 AUC, 84.95 accuracy, 85.70 sensitivity, 81.51 specificity and 81.99 F1 score. Conclusion: The proposed model is multiple instances learning-based deep learning model for video atrial septal defect detection which effectively improves ASD detection accuracy when compared to the performances of previous networks and clinical doctors.
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- 2023
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3. Corrigendum to 'Primary squamous cell carcinoma of the thyroid: A systematic review' [Asian J. Surg. 45(4) (2022) 1016–1017]
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Zeng Lu, Chen Lijun, Da Dezhuan, and Cai Hongyi
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Surgery - Published
- 2022
4. Back-Calculation Method of Rock Mass Pressure in a Shallow-Buried Super Large-Span Tunnel Using Upper-Bench CD Method
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Yunfei Wu, Jianxun Chen, Yanbin Luo, Yao Li, Chen Lijun, Weiwei Liu, Dong Fangfang, and Zhou Shi
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Stress field ,Bearing (mechanical) ,Deformation (mechanics) ,law ,Mode (statistics) ,Diaphragm (mechanical device) ,Geotechnical engineering ,Excavation ,Span (engineering) ,Rock mass classification ,Geology ,Civil and Structural Engineering ,law.invention - Abstract
Rock mass pressure has always been a research hotspot in the field of tunnel engineering, especially in the super large-span tunnel, which is characterized by flat section, large excavation span, and complex stress field. Based on the Letuan Tunnel (a bi-directional tunnel with eight traffic lanes) of Binlai expressway expansion project in Shandong Province, China, this paper focused on the calculation method of rock mass pressure and the evolution law of load release in the construction process of the super large-span tunnel excavated by upper-bench central diaphragm (CD) method. Based on field measured data of Letuan Tunnel, the deformation behavior of primary lining and the distribution state of rock mass pressure during the tunnel construction were analyzed. According to the bearing mode of supporting structure, the mechanical models of different construction stages were established. Then, the rock mass pressures in different construction stages were back-calculated using mechanical models and compared with the measured values, and the evolution law of load release during the tunnel construction was discussed. The study results show that the tunnel deformation and rock mass pressure were significantly affected by the construction process and support form, and the excavation span was the key factor affecting the stability of rock mass. For the shallow-buried super large-span tunnel constructed by upper-bench CD method, the primary support of upper bench was under eccentric pressure. The comparison between the back-calculated value and the field measured value indicated that they were similar, and the average relative error was 17.23%. According to the concept of load release coefficient proposed in this paper, the load release coefficient after the pilot tunnel ahead (Part I) excavation reached 63%, and the load release coefficient after the pilot tunnel behind excavation (Part II) was 37%, which means that the rock mass pressure of Part I is increased about 59% due to the excavation of Part II.
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- 2021
5. The Microbial Community Structure of Rhizosphere Soil was Influenced by Different Sugarcane Varieties with Different Ratooning Abilities
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Shasha Luo, Yuxing An, Chen Lijun, Jihu Lia, Lu Yinglin, Sixing Daia, and Donglei Sun
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chemistry.chemical_classification ,Rhizosphere ,biology ,Soil carbon ,biology.organism_classification ,Ratooning ,Microbial population biology ,chemistry ,Agronomy ,Organic matter ,Cane ,Sugar ,Agronomy and Crop Science ,Nitrogen cycle - Abstract
Strong ratoon ability is the key factor in improving sugarcane productivity and reducing production costs. Soil microorganisms are sensitive to environmental changes and play an important role in regulating soil ecological functions. However, the impacts of sugarcane varieties with different ratooning abilities on soil microorganisms are poorly understood. Therefore, two common cultivated varieties with different ratooning abilities (Yuetang 94-128 with strong ratooning ability and Yuetang 03-373 with low ratooning ability) were selected to study the effects of sugarcane varieties on sugarcane yield and microbial community structure from 2017 to 2019 in South China. The Illumina MiSeq platform was applied in the present study to detect the diversity and community structure of rhizosphere soil bacteria and fungi in the different sugarcane varieties in 2019. The results showed that sugarcane cane yield and sugar yield were higher in Yuetang 94-128 during the three years, whereas the sugar content was lower in Yuetang 94-128 than in Yuetang 03-373 during this time. Different years influenced cane yield and sugar yield, while the sucrose content remained stable during the different years. The pH, organic matter (SOM) and total nitrogen (TN) contents were significantly lower in Yuetang 03-373 than in Yuetang 94-128, whereas the other indices had no significant difference between the different varieties. The α-diversity of sugarcane rhizosphere soil bacteria and fungi was not significantly different between the different varieties. Compared with Yuetang 03-373, the increase in bacterial taxa associated with the soil carbon and nitrogen cycles may be one of the reasons for the strong ratooning of Yuetang 94-128. The difference in rare fungal taxa between the two sugarcane varieties may lead to different ecological functions in the soil. Redundancy analysis (RDA) and Mantel test showed that the soil physical and chemical properties did not significantly influence the microbial community structure, which could indicate that sugarcane variety was the primary variable responsible for microbial community structure. This study provided important information on the rhizosphere soil microbial community structure of different sugarcane varieties with different ratooning abilities and provided a theoretical basis for improving the ratooning ability of sugarcane varieties from the perspective of improving soil microbial community.
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- 2021
6. Experience Report
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Chen, Lijun, Grochow, Joshua A., Layer, Ryan, and Levet, Michael
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FOS: Computer and information sciences ,Computer Science - Computers and Society ,Computers and Society (cs.CY) ,ComputingMilieux_COMPUTERSANDEDUCATION ,97-02, 97D40, 97D60, 97P20 ,K.3.2 - Abstract
We report our experiences implementing standards-based grading at scale in an Algorithms course, which serves as the terminal required CS Theory course in our department's undergraduate curriculum. The course had 200-400 students, taught by two instructors, eight graduate teaching assistants, and supported by two additional graders and several undergraduate course assistants. We highlight the role of standards-based grading in supporting our students during the COVID-19 pandemic. We conclude by detailing the successes and adjustments we would make to the course structure., Comment: This is an extended version of our paper, which will appear in ITiCSE 2022
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- 2022
7. CamLiFlow: Bidirectional Camera-LiDAR Fusion for Joint Optical Flow and Scene Flow Estimation
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Liu, Haisong, Lu, Tao, Xu, Yihui, Liu, Jia, Li, Wenjie, and Chen, Lijun
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FOS: Computer and information sciences ,Computer Vision and Pattern Recognition (cs.CV) ,Computer Science - Computer Vision and Pattern Recognition - Abstract
In this paper, we study the problem of jointly estimating the optical flow and scene flow from synchronized 2D and 3D data. Previous methods either employ a complex pipeline that splits the joint task into independent stages, or fuse 2D and 3D information in an "early-fusion" or "late-fusion" manner. Such one-size-fits-all approaches suffer from a dilemma of failing to fully utilize the characteristic of each modality or to maximize the inter-modality complementarity. To address the problem, we propose a novel end-to-end framework, called CamLiFlow. It consists of 2D and 3D branches with multiple bidirectional connections between them in specific layers. Different from previous work, we apply a point-based 3D branch to better extract the geometric features and design a symmetric learnable operator to fuse dense image features and sparse point features. Experiments show that CamLiFlow achieves better performance with fewer parameters. Our method ranks 1st on the KITTI Scene Flow benchmark, outperforming the previous art with 1/7 parameters. Code is available at https://github.com/MCG-NJU/CamLiFlow., Comment: Accepted to CVPR 2022 (Oral)
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- 2022
8. Corrigendum: Phylogeny and Taxonomy on Cryptic Species of Forked Ferns of Asia
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Wei, Zuoying, Xia, Zengqiang, Shu, Jiangping, Shang, Hui, Maxwell, Stephen J., Chen, Lijun, Zhou, Xile, Xi, Wang, Adjie, Bayu, Yuan, Quan, Cao, Jianguo, and Yan, Yuehong
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Plant Science - Published
- 2022
9. Effect of physiological aging on binocular vision
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Chen Lijun, Shuhan Fan, Yifan Wu, Chang-Bing Huang, Hongyu Lv, and Fang-Fang Yan
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Binocular rivalry ,Aging ,Vision, Binocular ,Vision Disparity ,genetic structures ,05 social sciences ,eye diseases ,050105 experimental psychology ,Large sample ,03 medical and health sciences ,0302 clinical medicine ,Stereopsis ,Physiological Aging ,Younger adults ,Humans ,Optometry ,0501 psychology and cognitive sciences ,Psychology ,Binocular vision ,030217 neurology & neurosurgery ,General Psychology ,Aged - Abstract
We see the world with two eyes. Binocular vision provides more ample information through interocular interaction. Previous studies have shown that aging impairs a variety of visual functions, but how aging affects binocular vision is still unclear. In this study, we measured three typical binocular functions-binocular combination, binocular rivalry, and stereo vision-to investigate aging-related effects on binocular vision in a relatively large sample (48 younger adults and 27 older adults) with normal or corrected-to-normal distance vision and no ophthalmological and mental diseases. We found that there were no consistent aging-related declines in binocular vision, with the worst effect on alternation frequency in binocular rivalry and no effect on binocular phase combination and stereo vision tested by Titmus. In addition, aging changed the correlation pattern among some of these binocular functions. These results reflected (at least partially) different aging-related mechanism(s) in binocular vision.
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- 2021
10. Deformation Behaviors and Mechanical Mechanisms of Double Primary Linings for Large-Span Tunnels in Squeezing Rock: A Case Study
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Yunfei Wu, Zhou Shi, Chen Lijun, Weiwei Liu, Jianxun Chen, and Yanbin Luo
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Stress (mechanics) ,Large deformation ,Computer simulation ,Schist ,Geology ,Geotechnical engineering ,Vertical displacement ,Deformation (meteorology) ,Geotechnical Engineering and Engineering Geology ,Span (engineering) ,Control methods ,Civil and Structural Engineering - Abstract
Large deformation has always been a focus and difficult issue in the construction of deep-buried tunnels in squeezing rock. Previous studies mainly focused on the large deformation of medium and small span railway/highway tunnels in soft ground. However, there are limited researches on the large deformation control methods for large-span (three-lane) highway tunnels constructed in unfavorable geological environment. Based on the Lianchengshan Tunnel of the Baoji-Hanzhong expressway in Shaanxi Province, China, this paper studied the deformation behaviors and mechanical mechanisms of a large-span tunnel excavated in chlorite schist formation with single primary lining method and double primary lining method by in-situ test and numerical simulation. The achieved results indicate that the double primary lining method is much more effective than that of the single primary lining method in restraining the deformation of surrounding rock, and the maximum vertical displacement and horizontal convergence are reduced by 67% and 66%, respectively. The support method of double HK200b-type steel sets combined with large-diameter foot reinforcement bolt (FRB) and deep invert could effectively control the large deformation of the case tunnel, which effectively avoided the supporting structure failure, repeated clearance invasion and multiple reshaping work caused by the single primary lining method and conformed to the energy-saving construction concept of “no clearance interfering, no support reshaping” of tunnels in squeezing ground. Simulation analysis of surrounding rock deformation, supporting structure stress and plastic zone distribution was performed to evaluate the support effect of the two deformation-controlled methods. Finally, the deformation and stress characteristic curves of rock-support of the two deformation-controlled methods were established, which revealed the supporting mechanism of double primary linings for large-span tunnels in chlorite schist. The research results can provide a theoretical basis and practical reference for the large-deformation control of similar large-span tunnels in squeezing rock.
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- 2021
11. Performance of Tunnel Feet-Lock Pipe (TFP) in Sharing Vertical Foundation Load
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Yao Li, Chen Lijun, Yongjun Mu, Jianxun Chen, Wang Chuanwu, Hu Taotao, and Yanbin Luo
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Bearing (mechanical) ,Settlement (structural) ,0211 other engineering and technologies ,Foundation (engineering) ,Vertical load ,02 engineering and technology ,Lock (computer science) ,law.invention ,Subgrade reaction ,law ,021105 building & construction ,Geotechnical engineering ,Bearing capacity ,Total factor productivity ,021101 geological & geomatics engineering ,Civil and Structural Engineering ,Mathematics - Abstract
During the tunnel construction in soft ground, the insufficient bearing capacity of tunnel foundation usually causes a series of settlement problems. Tunnel feet-lock pipe (TFP) has been widely used to take the vertical load acting at the foundation of a tunnel foot. However, the detailed bearing performance of TFP is still not clear, and there is a lack of quantitative research. In this paper, a simple analytical approach is adopted to evaluate the performance of the TFP, and the main parameters affecting the supporting performance of the TFP are analyzed. The results show that the ϕ42–ϕ140 TFP with the angle of 10° can take 3.8%–40.4% of vertical load. TFP has an effective length of 1.7 m–2.8 m, which is related to the relative stiffness between the TFP and the stratum. With the increase of the installation angle, the TFP shares more vertical load. This trend is more obvious when the angle of the TFP is greater than 20°. If the proportion coefficient of the subgrade reaction coefficient is doubled, the vertical load shared by the TFP can be increased by 34%–38%. For every 10 cm increase in overbreak behind the steel rib, the vertical load shared by TFP is reduced by 16%.
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- 2021
12. Effects of Pesticide–Fertilizer Combinations on the Rhizosphere Microbiome of Sugarcane: A Preliminary Study
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Weijuan Huang, Yuxing An, Lu Yinglin, Donglei Sun, Chen Lijun, and Dai Sixing
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0106 biological sciences ,Soil health ,Rhizosphere ,business.industry ,Clothianidin ,04 agricultural and veterinary sciences ,Biology ,engineering.material ,Pesticide ,01 natural sciences ,Biotechnology ,chemistry.chemical_compound ,chemistry ,040103 agronomy & agriculture ,engineering ,0401 agriculture, forestry, and fisheries ,Fertilizer ,Microbiome ,business ,Agronomy and Crop Science ,Organic fertilizer ,Nitrogen cycle ,010606 plant biology & botany - Abstract
A functional pesticide–fertilizer combination is in high demand due to the many potential advantages, including the dual reduction in pesticide and fertilizer inputs, increased crop yield, safe to use, and environmental friendly. To investigate the impact of a pesticide–fertilizer on the soil environment of sugarcane, the effects of clothianidin and/or organic fertilizer treatments on the diversity, structure, and function of the rhizosphere bacterial community were studied using 16S rRNA gene sequencing in 2019 at Guangzhou Sugarcane Research Institute. The bacterial community treated with the pesticide–fertilizer displayed a higher diversity compared with the control treatments (added with pesticide or fertilizer only). The dynamic changes of the bacterial community structure revealed that the pesticide–fertilizer treatment showed a significant variation in the second week. Functional analysis demonstrated that four bacterial genera, including Dyella, Mucilaginibacter, Massilia, and Telmatospirillum, could play an important role in degrading clothianidin and improving soil health. The relative abundance of nitrogen cycle genes showed that the nitrification-related gene pmoA-amoA and denitrification-related genes nirK and norB were increased significantly in the pesticide–fertilizer treatment compared with that of the control treatments. This preliminary study provides a good basis to understand the effect of a pesticide–fertilizer integration on the soil rhizosphere microbiome which would be helpful for the evaluation of its application in the field.
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- 2020
13. Study on the negative effect of internal-control willingness on enterprise risk-taking
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Chen, Lijun, Li, Yanxi, and Liu, Bin
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General Psychology - Abstract
In the traditional cognition, the factors that affect the level of internal control are usually based on the objective factors such as corporate characteristics, financial status, and governance structure. However, the internal control defects of many famous companies expose the phenomenon of subjective manipulation, and this leads us to focus on the subjective factor of internal control, which we call internal-control willingness. We define “internal-control willingness” as the degrees of subjective initiative of the internal-control construction and execution activities. Additionally, we propose a method for measuring internal-control willingness, using text analysis and machine learning. Then, we examine the impact of internal-control willingness on enterprise risk-taking, through the internal-control, financial, and market data of China A-share main board enterprises in 2011–2018. The study found that (1) internal-control willingness has a significant positive impact on internal-control level, which can fairly achieve the measurement of internal-control subjective initiative. (2) It confirms that internal-control willingness lowers corporate risk-taking. (3) Further research finds that state-owned enterprises strengthen internal-control willingness and their risk-taking level is significantly lower than that of non-state-owned enterprises. This paper suggests that the regulatory authorities actively urge the board of directors to strengthen internal-control willingness.
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- 2022
14. Lightning Protection Safety Risk Assessment Method for Key Units of Meteorological Disaster Prevention
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Jin Lin, Zhang Xinxin, Chen Lijun, and Hu Xiaowan
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- 2022
15. sj-docx-1-pss-10.1177_09567976211056620 – Supplemental material for Identifying Long- and Short-Term Processes in Perceptual Learning
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Yang, Jia, Yan, Fang-Fang, Chen, Lijun, Fan, Shuhan, Wu, Yifan, Jiang, Lei, Xi, Jie, Zhao, Junlei, Zhang, Yudong, Lu, Zhong-Lin, and Huang, Chang-Bing
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FOS: Psychology ,FOS: Clinical medicine ,170199 Psychology not elsewhere classified ,110319 Psychiatry (incl. Psychotherapy) ,110904 Neurology and Neuromuscular Diseases ,Neuroscience - Abstract
Supplemental material, sj-docx-1-pss-10.1177_09567976211056620 for Identifying Long- and Short-Term Processes in Perceptual Learning by Jia Yang, Fang-Fang Yan, Lijun Chen, Shuhan Fan, Yifan Wu, Lei Jiang, Jie Xi, Junlei Zhao, Yudong Zhang, Zhong-Lin Lu and Chang-Bing Huang in Psychological Science
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- 2022
- Full Text
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16. sj-docx-1-pss-10.1177_09567976211056620 – Supplemental material for Identifying Long- and Short-Term Processes in Perceptual Learning
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Yang, Jia, Yan, Fang-Fang, Chen, Lijun, Fan, Shuhan, Wu, Yifan, Jiang, Lei, Xi, Jie, Zhao, Junlei, Zhang, Yudong, Lu, Zhong-Lin, and Huang, Chang-Bing
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FOS: Psychology ,FOS: Clinical medicine ,170199 Psychology not elsewhere classified ,110319 Psychiatry (incl. Psychotherapy) ,110904 Neurology and Neuromuscular Diseases ,Neuroscience - Abstract
Supplemental material, sj-docx-1-pss-10.1177_09567976211056620 for Identifying Long- and Short-Term Processes in Perceptual Learning by Jia Yang, Fang-Fang Yan, Lijun Chen, Shuhan Fan, Yifan Wu, Lei Jiang, Jie Xi, Junlei Zhao, Yudong Zhang, Zhong-Lin Lu and Chang-Bing Huang in Psychological Science
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- 2022
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17. Variation of Rock Mass Pressure during Tunnel Construction in Phyllite Stratum
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Chen Lijun, Zeguang Song, Wang Chuanwu, Yao Li, Jianxun Chen, Yanbin Luo, and Diao Pengsheng
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Article Subject ,Phyllite ,Settlement (structural) ,General Mathematics ,0211 other engineering and technologies ,General Engineering ,Excavation ,02 engineering and technology ,Deformation (meteorology) ,Engineering (General). Civil engineering (General) ,021105 building & construction ,QA1-939 ,Geotechnical engineering ,Bearing capacity ,TA1-2040 ,Arch ,Rock mass classification ,Mathematics ,Geology ,021101 geological & geomatics engineering ,Stratum - Abstract
In this paper, the field monitoring method is used to study the variation of rock mass pressure during the construction of a tunnel in phyllite stratum, and three functions are used to fit and analyze the variation of rock mass pressure with deformation, excavation time, and space. The results show the following (1) When the deformation increases significantly, the rock mass pressure decreases firstly and then increases. This is caused by the insufficient bearing capacity of the rock mass in the arch foot of the supporting structure after the excavation of the upper bench, which leads to a settlement of supporting structure and surrounding rock. (2) Compared with other kinds of fitting functions, the logistic function can better characterize the variation of the pressure of surrounding rock with deformation, excavation time, and distance from the face. This paper provides a reliable reference for the design and construction of the tunnel in phyllite stratum. The logistic function can be used to present and predict the change of rock mass pressure with deformation, excavation time, and space in similar rock mass conditions.
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- 2020
18. Lycium barbarum Polysaccharide Inhibited Hypoxia-Inducible Factor 1 in COPD Patients
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Hui-Fang Zhang, Yuan Xu, Yan-Hong Liu, Xiao-Bo Huang, Ma Xiuqin, Chao Chen, Ya-Ping Li, Wang Xu, Li-Jun Wang, Geng-Geng Yu, Chen Lijun, Li-Ting Ma, and Jie Wu
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COPD ,medicine.medical_specialty ,biology ,business.industry ,Copd patients ,Healthy subjects ,General Medicine ,medicine.disease ,biology.organism_classification ,Gastroenterology ,pCO2 ,Pathophysiology ,Lycium barbarum polysaccharide ,respiratory tract diseases ,03 medical and health sciences ,0302 clinical medicine ,030228 respiratory system ,Oral administration ,Internal medicine ,Medicine ,030212 general & internal medicine ,Lycium ,business - Abstract
Background Chronic obstructive pulmonary disease (COPD) is a chronic airway inflammatory disease characterized by irreversible airflow obstruction. Pathogenic mechanisms underlying COPD remain largely unknown. Objective The current study was designed to explore serum concentration of hypoxia-inducible factor 1α (HIF-1α) in stable COPD patients and the potential effect of Lycium barbarum polysaccharides (LBP) on HIF-1α protein expression. Methods Serum HIF-1α was quantified by ELISA in 102 stable COPD patients before and after 2-week orally taken LBP (100 mL/time, twice daily, 5-15 mg/mL). Correlation of serum LBP and lung function (FEV1%) or blood gas (PO2 and PCO2) was also analyzed. As a control, 105 healthy subjects were also enrolled into this study. Results Serum concentration of HIF-1α was significantly higher in the stable COPD patients (37.34 ± 7.20 pg/mL) than that in the healthy subjects (29.55 ± 9.66 pg/mL, P
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- 2020
19. Nonlinear deformation behaviors and a new approach for the classification and prediction of large deformation in tunnel construction stage: a case study
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Jianxun Chen, Yunfei Wu, Chen Lijun, Zhou Shi, Weiwei Liu, and Yanbin Luo
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Environmental Engineering ,Large deformation ,Fuzzy analytic hierarchy process ,Computer science ,business.industry ,0211 other engineering and technologies ,02 engineering and technology ,Structural engineering ,Tunnel construction ,Important research ,Order (business) ,Nonlinear deformation ,021105 building & construction ,Stage (hydrology) ,business ,021101 geological & geomatics engineering ,Civil and Structural Engineering - Abstract
Reasonable evaluation and prediction of squeezing condition to avoid large deformation disaster in tunnels have been an important research issue. In order to accurately and rapidly predict the larg...
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- 2020
20. Failure Mechanisms and Modes of Tunnels in Monoclinic and Soft-Hard Interbedded Rocks: A Case Study
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Yao Li, Chen Lijun, Weiwei Liu, Gao Haijiang, Yanbin Luo, Jianxun Chen, and Daochuan Zhong
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0211 other engineering and technologies ,Magnetic dip ,02 engineering and technology ,Slip (materials science) ,Spall ,Instability ,Transverse plane ,Shear (geology) ,Buckling ,021105 building & construction ,Geotechnical engineering ,Geology ,021101 geological & geomatics engineering ,Civil and Structural Engineering ,Monoclinic crystal system - Abstract
The issue of large deformation mechanism in soft rock tunnels has puzzled tunnel scholars for decades. Previous studies have not evolved a clear and common understanding. Therefore, detailed on-site measurement, full investigation and statistical analysis have been conducted on the instability and failure of Muzhailing Tunnel since its construction, whose length is beyond 15 km. The study aims at systematically analyzing the failure mechanisms and modes of Muzhailing Tunnel in monoclinic and soft-hard interbedded rock strata. Study results show that the angle between strata strike and tunnel axis greatly determines the magnitude of deformation, the dip direction significantly controls the bias direction and maximum deformation direction, and the dip angle deeply affects the deformation form. The failure modes of surrounding rock mainly include four types: spalling and overturning failure, bending failure, shear slip failure and buckling failure. Large deformation characteristics are summarized from six aspects: failure form, groundwater, sensitivity to influencing factors, deformation degree, deformation speed and deformation duration. The instability modes of primary lining include in-plane (transverse) instability and out-plane (longitudinal) instability. Finally, the causes of large deformation are analyzed from geological, structural, engineering and human factors.
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- 2020
21. Supervision’s Guidance Style and Graduated Students’ Academic Motivation: Mediating Role of the Negative Academic Emotion
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Jiang Xiaoliu and Chen Lijun
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Rehabilitation ,Physical Therapy, Sports Therapy and Rehabilitation ,General Medicine ,Psychology ,Social psychology ,Style (sociolinguistics) - Published
- 2020
22. Constrained Reinforcement Learning for Vehicle Motion Planning with Topological Reachability Analysis
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Shangding Gu, Guang Chen, Lijun Zhang, Jing Hou, Yingbai Hu, Alois Knoll
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ddc - Published
- 2021
23. Primary squamous cell carcinoma of the thyroid: A systematic review
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Zeng, Lu, Chen, Lijun, Da, Dezhuan, and Cai, Hongyi
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Carcinoma, Squamous Cell ,Humans ,Surgery ,Thyroid Neoplasms - Published
- 2022
24. Super-radiation Terahertz Source Based On Sub-picosecond Electron Beam At CTFEL
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Xingfan Yang, Lanbin Li, Ming Li, Jie Liu, Yong Xu, Xuming Shen, Hanbin Wang, Peng Zhang, Chenglong Lao, Yu Liu, Chen Lijun, Kui Zhou, Dexin Xiao, Dai Wu, Peng Li, Jianxin Wang, Lijun Shan, Zheng Zhou, Xing Luo, Longgang Yan, and Tianhui He
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Range (particle radiation) ,Optics ,Materials science ,business.industry ,Terahertz radiation ,Picosecond ,Free-electron laser ,Cathode ray ,Undulator ,Radiation ,business - Abstract
China Academy of Engineering Physics Terahertz Free Electron Laser (CTFEL) works in the range of 0.7~4.2 THz. To expand the range below 0.1 THz, we developed a super-radiation terahertz (THz) source based on sub-picosecond electron beam behind CTFEL. The sub-picosecond electron beam was generated by velocity compression and then injected into undulator to provide THz wave. In this proceeding, the preliminary experimental results of super-radiation terahertz source were reported.
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- 2021
25. Impact of pesticide/fertilizer mixtures on the rhizosphere microbial community of field-grown sugarcane
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Yuxing An, Lu Yinglin, Weijuan Huang, Donglei Sun, and Chen Lijun
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Rhizosphere ,biology ,Clothianidin ,Environmental Science (miscellaneous) ,engineering.material ,Pesticide ,biology.organism_classification ,Agricultural and Biological Sciences (miscellaneous) ,Paenibacillus ,chemistry.chemical_compound ,Microbial population biology ,chemistry ,Agronomy ,engineering ,Original Article ,Fertilizer ,Microbiome ,Organic fertilizer ,Biotechnology - Abstract
The rhizosphere microbial community is important for plant health and is shaped by numerous environmental factors. This study aimed to unravel the effects of a pesticide/fertilizer mixture on the soil rhizosphere microbiome of field-grown sugarcane. A field trial on sugarcane was conducted in Zhanjian City, Guangdong Province, China, and soil samples from the rhizosphere were collected after clothianidin pesticide and/or organic fertilizer treatments. The effects of pesticide and/or organic fertilizer treatments on the composition, diversity, and predictive function of the rhizosphere microbial communities were examined using 16S rRNA gene and ITS1 amplicon sequencing. Compared with the controls (no pesticide or fertilizer used), the microbial community that resulted from treatment with the pesticide/fertilizer mixture (SPF) had a higher relative bacterial diversity and fungal richness, and contributed more beneficial functions to sugarcane, including xenobiotics biodegradation and metabolism of amino acids. The bacterial and fungal compositions at various taxonomic levels were not significantly different in SPF and SP (pesticide only) treatments compared to treatments without the pesticide, suggesting that the clothianidin addition did not cause a detrimental impact on the soil microbiome. Moreover, five bacterial genera, including Dyella, Sphingomonas, Catenulispora, Mucilaginibacter, and Tumebacillus, were significantly more abundant in the SPF and SP treatments, which could be associated with the pesticide addition. With the addition of organic fertilizers in SPF, the abundances of some soil-beneficial bacteria Bacillus, Paenibacillus, and Brevibacillus were highly increased. Our study provides insights into the interactions between the rhizosphere soil microbiome and pesticide-fertilizer integration, which may help improve the application of pesticide-fertilizer to sugarcane fields. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02770-3.
- Published
- 2021
26. Improved Simple Sample Pretreatment Method for Quantitation of Major Human Milk Oligosaccharides Using Ultrahigh Pressure Liquid Chromatography with Fluorescence Detection
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Yanhui Han, Chen Lijun, Hang Xiao, Yang Chunying, Juncai Hou, Tiemin Jiang, Qiao Weicang, Baoli Zhu, and Huang Xunwen
- Subjects
0106 biological sciences ,Ultrafiltration ,Oligosaccharides ,Centrifugation ,Pretreatment method ,01 natural sciences ,Matrix (chemical analysis) ,Simple sample ,Humans ,Sample preparation ,Chromatography, High Pressure Liquid ,health care economics and organizations ,chemistry.chemical_classification ,Chromatography ,Milk, Human ,010401 analytical chemistry ,General Chemistry ,Oligosaccharide ,Fluorescence ,0104 chemical sciences ,chemistry ,Female ,General Agricultural and Biological Sciences ,010606 plant biology & botany - Abstract
Human milk oligosaccharides (HMOs) maintain and promote infant health. Most of the current methods for HMOs quantitation require labor-intensive and time-consuming steps for sample preparation. This study presents two very simple and easy-to-operate pretreatment methods, requiring either ultrafiltration or centrifugation to separate free oligosaccharides from whole fat human milk and other milk matrix before oligosaccharides labeling for quantifying HMOs using ultrahigh pressure liquid chromatography with fluorescence detection. A single chromatography run quantified 15 sialylated and neutral HMOs with high sensitivity (with an LOD less than 8 pg for all HMOs tested: about 1 pg for 2'-fucosyllactose, 3-fucosyllactose, 4'-galactosyllactose, 3'-galactosyllactose, and 6'-galactosyllactose) and good linearity with coefficient of correlation above 0.999. Accuracy and precision were satisfactory for both pretreatment methods. Overall, the centrifugation pretreatment was efficient and reliable for samples with high levels of oligosaccharides, and the ultrafiltration pretreatment was especially suitable for samples with low oligosaccharide abundance.
- Published
- 2019
27. Synthesis and Properties of Cross-linked Fluorine and Silicon VAc-VeoVa Polymer Latex Emulsified by Green Mixed Surfactant
- Author
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Xiuming Wang, Chen Lijun, Yilu Gong, Zhijuan Sun, and Tantan Shao
- Subjects
chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,chemistry ,Silicon ,Chemical engineering ,Pulmonary surfactant ,Materials Chemistry ,Fluorine ,chemistry.chemical_element ,Polymer - Published
- 2019
28. Species inventory and assessment of large- and medium-size mammals and pheasants using camera trapping in the Chebaling National Nature Reserve, Guangdong Province
- Author
-
Chen Lijun, Xiao Ronggao, Xiao Zhishu, Shu Zufei, Huang Xiaoqun, and Song Xiangjin
- Subjects
Fishery ,Nature reserve ,Geography ,Ecology ,Trapping ,Ecology, Evolution, Behavior and Systematics ,National nature reserve ,Nature and Landscape Conservation - Published
- 2019
29. Preliminary surveys of mammals and birds by infrared camera traps in the Sichuan Baishuihe National Nature Reserve
- Author
-
Song Dazhao, Xiao Zhishu, Hu Daming, Deng Yue, Wang Xingzhe, Chen Yuelong, Yang Weihe, Luo Xiuhai, and Chen Lijun
- Subjects
Fishery ,Geography ,Ecology ,Ecology, Evolution, Behavior and Systematics ,National nature reserve ,Nature and Landscape Conservation - Published
- 2019
30. Using occupancy models in wildlife camera-trapping monitoring and the study case
- Author
-
Shu Zufei, Zhang Yingming, Xiao Zhishu, Chen Lijun, Xiao Wenhong, Yao Wutao, and Ma Yong
- Subjects
Ecology ,biology ,Occupancy ,Wildlife ,Camera trap ,Environmental science ,Trapping ,Masked palm civet ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation ,Remote sensing - Published
- 2019
31. Application of camera-trapping data to study daily activity patterns of Galliformes in Guangdong Chebaling National Nature Reserve
- Author
-
Shu Zufei, Chen Lijun, and Xiao Zhishu
- Subjects
Galliformes ,Geography ,Ecology ,biology ,Kernel density estimation ,Trapping ,Physical geography ,biology.organism_classification ,Ecology, Evolution, Behavior and Systematics ,National nature reserve ,Nature and Landscape Conservation - Published
- 2019
32. The Mechanism Study of Rounded AA Damage Defect after POLY Loop
- Author
-
Zheng Haichang, Zhang Chi, Zhu Xiaobin, Chen Lijun, Wang Xiaolong, and Zhang Yu
- Subjects
Loop (topology) ,Mechanism (engineering) ,Materials science ,CMOS ,Ultra-high vacuum ,Particle ,Wafer ,Composite material ,Layer (electronics) - Abstract
AA damage is a common defect caused by particle residue, charge accumulation, abnormal etch and so on. In the actual production process, on different products such as logical and CMOS, it is found that the AA damage with the same characteristics can be observed after POLY loop to show regular circular and annular distribution, but impact wafer cannot find the regularity. In this paper, for the same form AA damage defect occurring after the POLY Loop, according to the impact wafer condition, and the information such as the condition of the front film, the etch condition and the pretreatment mode are deeply investigated, and the reasons for the AA damage defect are obtained: insufficient etch selection ratio, high vacuum cavity operation in the front layer and the influence of particle. The experimental results show that the generation of this type of AA damage can be effectively improved by prohibiting the operation of high vacuum cavity, adopting the pretreatment of removing particle and selecting the high selection ratio when the process is established.
- Published
- 2021
33. The photoresist developing ability study at different contact angle and mask transmission rate
- Author
-
Zheng Haichang, Chen Jiawen, Qin Lipeng, Yin Pengteng, Chen Lijun, and Wang Xiaolong
- Subjects
chemistry.chemical_classification ,Contact angle ,Materials science ,Pulmonary surfactant ,Resist ,chemistry ,Wafer ,Polymer ,Edge (geometry) ,Photoresist ,Composite material ,Layer (electronics) - Abstract
The PFOA surfactant (chemical structure: (polymer backbone)-C8F17) using in photoresist is forbade own to every country need protect environment, so the PFOA surfactant is replaced by non PFOA type (chemical structure: (polymer)-(CF2) n2 -CF3, n2
- Published
- 2021
34. Smoothed Least-Laxity-First Algorithm for EV Charging
- Author
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Chen, Niangjun, Kurniawan, Christian, Nakahira, Yorie, Chen, Lijun, and Low, Steven H.
- Subjects
Optimization and Control (math.OC) ,FOS: Electrical engineering, electronic engineering, information engineering ,FOS: Mathematics ,Systems and Control (eess.SY) ,Electrical Engineering and Systems Science - Systems and Control ,Mathematics - Optimization and Control - Abstract
Adaptive charging can charge electric vehicles (EVs) at scale cost effectively, despite the uncertainty in EV arrivals. We formulate adaptive EV charging as a feasibility problem that meets all EVs' energy demands before their deadlines while satisfying constraints in charging rate and total charging power. We propose an online algorithm, smoothed least-laxity-first (sLLF), that decides the current charging rates without the knowledge of future arrivals and demands. We characterize the performance of the sLLF algorithm analytically and numerically. Numerical experiments with real-world data show that it has a significantly higher rate of feasible EV charging than several other existing EV charging algorithms. Resource augmentation framework is employed to assess the feasibility condition of the algorithm. The assessment shows that the sLLF algorithm achieves perfect feasibility with only a 0.07 increase in resources., Comment: 14 pages, 4 figures
- Published
- 2021
- Full Text
- View/download PDF
35. sj-pdf-1-crd-10.1177_14799731211060051 ��� Supplemental Material for The association of blood urea nitrogen levels upon emergency admission with mortality in acute exacerbation of chronic obstructive pulmonary disease
- Author
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Chen, Lan, Chen, Lijun, Zheng, Han, Wu, Sunying, and Wang, Saibin
- Subjects
110203 Respiratory Diseases ,endocrine system ,viruses ,FOS: Clinical medicine ,111702 Aged Health Care ,FOS: Health sciences - Abstract
Supplemental Material, sj-pdf-1-crd-10.1177_14799731211060051 for The association of blood urea nitrogen levels upon emergency admission with mortality in acute exacerbation of chronic obstructive pulmonary disease by Lan Chen, Lijun Chen, Han Zheng, Sunying Wu and Saibin Wang in Chronic Respiratory Disease
- Published
- 2021
- Full Text
- View/download PDF
36. Hot-spots and cutting-edge of forest park tourism research in China
- Author
-
陈丽军,万志芳 CHEN Lijun
- Subjects
Ecology ,Ecology, Evolution, Behavior and Systematics - Published
- 2021
37. Design and Realization of a Nanosatellite for Malaysia SiswaSAT Competition 2020
- Author
-
Kamal Hazim Kamal Bahrin, Mai Nurul Fareesya Mohamad Anuar, Muhammad Syukri Johari, Hariz Azamuddin Shafie, Mohamed Okasha, Muhammad Saalihaan Zil Kamal, Nur Aqilah Azman Shah, Chen Lijun, Mohamad Nurmirza Asyraaf Sulong, and Nurul Najihah Bakar
- Subjects
Payload ,Group method of data handling ,Computer science ,Control system ,Mission analysis ,Systems engineering ,Satellite ,Electric power ,Realization (systems) ,Space exploration - Abstract
This paper provides the conceptualization and the development of IIUMSAT-2, a nanosatellite that is designed by a group of engineering students from International Islamic University Malaysia (IIUM) to simulate an actual satellite ability in space. IIUMSAT-2 is an integrated system comprising Mechanical Subsystem, Payload Subsystem, Communication and Data Handling Subsystem (CDH), Electrical Power Subsystem, and Ground Control System. The nanosatellite is developed based on the Space Mission Analysis and Design (SMAD) approach. IIUMSAT-2 is able to communicate at a 200m distance, transmitting pressure, temperature, altitude, humidity, location, attitude, and flight images to the ground station wirelessly.
- Published
- 2020
38. Time-of-day Dependent Light Effects on Subjective Affect and Comfort
- Author
-
Jia Yang, Hua Yang, Changbing Huang, Yifan Wu, Chen Lijun, Fangfang Yan, and Shuhan Fan
- Subjects
medicine.medical_specialty ,Time of day ,education ,medicine ,Audiology ,Psychology ,Affect (psychology) ,Light effect - Abstract
Light, one of the key environmental components for both life and work, played significant role in subjective feelings (e.g. affect and comfort), but the exact effects and mechanisms were still to be determined. The present study screened thirty healthy adults (13 females, 22.45 ± 3.26 years) and examined subjective affect and comfort under short-term white lights with different combination of correlated color temperature (CCT) and illuminance at different times of day (e.g. morning, afternoon, and evening). Our results showed a significant interaction between illuminance level and time-of-day on subjective comfort. Participants felt more comfortable under 50 lx and 100 lx instead of 500 lx in the evening, and more comfortable under 500 lx in the morning and afternoon. In addition, a positive correlation between illuminance and comfort in the morning and a negative correlation between them in the evening were found. No significant effect of CCT on any subjective feeling was revealed. Our results necessitate the consideration of time-of-day in understanding lighting effects and application of healthy lighting in daily life.
- Published
- 2020
39. VCANet: Vanishing-Point-Guided Context-Aware Network for Small Road Object Detection
- Author
-
Guang Chen, Kai Chen, Lijun Zhang, Liming Zhang, Alois Knoll
- Subjects
ddc - Published
- 2020
40. Voltage optimization Strategy of Distribution Network Considering the Reactive Power of Energy Storage
- Author
-
Meng Yang, Chen Lijun, Guohua Cui, Hongfen Cui, Bo Yang, and Haoming Liu
- Subjects
Distribution networks ,Computer science ,020209 energy ,Node (networking) ,020208 electrical & electronic engineering ,02 engineering and technology ,Voltage optimisation ,AC power ,Energy storage ,Control theory ,Limit (music) ,0202 electrical engineering, electronic engineering, information engineering ,Voltage regulation ,Voltage - Abstract
More and more distributed generations (DGs) access to distribution networks makes the voltage regulation becomes more and more complicated. In order to solve the over limit problem of voltage, this paper proposes a method to optimize the reactive power and voltage of the distribution network by utilizing the reactive power capacity of energy storage. First, the influence of DG access on voltage and the reactive power capacity of energy storage are analyzed. Second, the coordination method of reactive power regulating resources in distribution network is proposed. Then, a voltage optimization model with energy storage participating in is established with the aim of minimizing the node voltage deviation in the distribution network and considering the equality and inequality constraints. Finally, the simulation results show that the proposed method can utilize the reactive power of energy storage and optimize the network voltage.
- Published
- 2020
41. The Efficacy Analysis of Transbronchoscopic Large Volume Lung Lavage in Treatment of Pneumoconiosis Complicated with Chronic Obstructive Pulmonary Disease
- Author
-
Xiaoyong Ma, Ma Xiuqin, Yan-Hong Liu, Chao Chen, Chen Lijun, and Wang Xu
- Subjects
COPD ,medicine.medical_specialty ,business.industry ,Pneumoconiosis ,Pulmonary disease ,medicine.disease ,respiratory tract diseases ,Quality of life ,Internal medicine ,Medicine ,Observation group ,Respiratory system ,business ,After treatment ,Volume lung - Abstract
Objective: To evaluate the efficacy of transbronchoscopic large volume lung lavage in the treatment of pneumoconiosis complicated with chronic obstructive pulmonary disease (COPD). Methods: The clinical data of 80 patients with pneumoconiosis complicated with COPD admitted to our hospital from June 2017 to January 2019 were retrospectively analyzed. 40 patients in the control group were treated with conventional drugs and 40 patients in the observation group treated with conventional drugs plus transbronchoscopic large-volume lung lavage. Dyspnea score and healthy quality of life were compared between the two groups. Results: the scores of dyspnea in the observation group were significantly lower than those in the control group at 12, 24 and 48 weeks after treatment, and the (SGRQ) scores of George's respiratory problems questionnaire in the observation group were significantly lower than those in the control group at 12, 24 and 48 weeks after treatment. Conclusion: Thetransbronchoscopic large volume of lung lavage has a significant effect on the treatment of pneumoconiosis patients with COPD, which can effectively reduce the degree of dyspnea and improve the quality of life.
- Published
- 2020
42. A Smoothed Analysis of Online Lasso for the Sparse Linear Contextual Bandit Problem
- Author
-
Liu, Zhiyuan, Wang, Huazheng, Waggoner, Bo, Youjian, Liu, and Chen, Lijun
- Subjects
FOS: Computer and information sciences ,Computer Science - Machine Learning ,Statistics - Machine Learning ,Machine Learning (stat.ML) ,Machine Learning (cs.LG) - Abstract
We investigate the sparse linear contextual bandit problem where the parameter $\theta$ is sparse. To relieve the sampling inefficiency, we utilize the "perturbed adversary" where the context is generated adversarilly but with small random non-adaptive perturbations. We prove that the simple online Lasso supports sparse linear contextual bandit with regret bound $\mathcal{O}(\sqrt{kT\log d})$ even when $d \gg T$ where $k$ and $d$ are the number of effective and ambient dimension, respectively. Compared to the recent work from Sivakumar et al. (2020), our analysis does not rely on the precondition processing, adaptive perturbation (the adaptive perturbation violates the i.i.d perturbation setting) or truncation on the error set. Moreover, the special structures in our results explicitly characterize how the perturbation affects exploration length, guide the design of perturbation together with the fundamental performance limit of perturbation method. Numerical experiments are provided to complement the theoretical analysis., Comment: 16 pages, 2 figures
- Published
- 2020
- Full Text
- View/download PDF
43. Pretreatment of printing and dyeing wastewater by Fe/C micro-electrolysis combined with H2O2 process
- Author
-
Chen Lijun, Wang Yan, Lan Tianxiang, Xianwei Wu, Jie Dai, and Ju Yi
- Subjects
chemistry.chemical_classification ,021110 strategic, defence & security studies ,Electrolysis ,Environmental Engineering ,Chemical oxygen demand ,0211 other engineering and technologies ,chemistry.chemical_element ,02 engineering and technology ,Biological Oxygen Demand Analysis ,010501 environmental sciences ,01 natural sciences ,law.invention ,chemistry ,law ,Degradation (geology) ,Organic matter ,Response surface methodology ,Carbon ,0105 earth and related environmental sciences ,Water Science and Technology ,Nuclear chemistry ,Waste disposal - Abstract
A novel iron-carbon (Fe/C) micro-electrolysis combined with H2O2 (ICMH) process was proposed to pretreat the printing and dyeing wastewater (PDW), using a micro-electrolysis filling. The effects of H2O2 concentration, reaction time, initial pH, and Fe/C dosage on chemical oxygen demand (COD) removal rate of PDW were optimized by response surface methodology (RSM). The maximum COD removal rate was approximately 77.65% after 186 min treatment, when the concentration of H2O2, initial pH and the dosage of Fe/C were 8.88 g/L, 1.5 and 837 g/L, respectively. Analysis of variance (ANOVA) showed a high coefficient of determination value (R2 = 0.9780). And H2O2 concentration and initial pH were the key factors to improve the treatment effect. UV-Vis spectra indicated that a significant blue shift at 220 nm, attributing that fused aromatic hydrocarbons were degraded effectively. 3D-EEM spectra analysis showed that the water samples of PDW mainly contained three kinds of organic matter: refractory fulvic acid, soluble microbial metabolites and aromatic proteins, and the degradation rate of these was 81.76%, 53.78% and 70.83%, respectively.
- Published
- 2018
44. Facile synthesis of polyamide 6 (PA6)-based thermoplastic elastomers with a well-defined microphase separation structure by melt polymerization
- Author
-
Faxue Li, Ruchao Yuan, Wu Dequn, Chen Lijun, Xueli Wang, Yu Jianyong, and Fan Shuo
- Subjects
Materials science ,Polymers and Plastics ,Organic Chemistry ,Mesophase ,Bioengineering ,02 engineering and technology ,Dynamic mechanical analysis ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Elastomer ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Differential scanning calorimetry ,Chemical engineering ,Polymerization ,Phase (matter) ,Polyamide ,Thermoplastic elastomer ,0210 nano-technology - Abstract
A facile “2-step” melt polymerization method with high efficiency, easy accessibility, little pollution and low cost was proposed to fabricate thermoplastic elastomers (TPAEs) composed of polyamide 6 (PA6) and poly(tetramethylene glycol) (PTMG). To elucidate the thermal properties of these TPAEs measured by differential scanning calorimetry (DSC), a three-phase system was represented: a “pure” PA6 crystalline phase, a phase-separated mesophase (soft phase domains embedded in a PA6 ordered phase matrix) and a mixed phase (PA6 disordered phase + soft segments). The X-ray technology, dynamic mechanical analysis (DMA) and transmission electron microscopy (TEM) results offered further support to the morphological structural interpretation. The soft segment weight fraction in the mixed phase (WSS) was found to be equal to the overall soft segment weight concentration (CSS). The multiple melting transitions (TM and TMMT) occurring in these TPAEs were assigned to the disruption of the “pure” PA6 crystalline phase and the phase-separated mesophase, respectively. Additionally, the prepared TPAEs demonstrated better thermal and mechanical properties than PEBAX®, one of the commercial elastomers, presenting the potential to be widely used in various industrial fields.
- Published
- 2018
45. Adaptive Feedback Linearization-based Predictive Control for Greenhouse Temperature
- Author
-
Chen Lijun, Du Shangfeng, Liang Meihui, and He Yaofeng
- Subjects
0209 industrial biotechnology ,Temperature control ,Computer science ,020209 energy ,Greenhouse ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,02 engineering and technology ,Energy consumption ,Kalman filter ,Root mean square ,Model predictive control ,020901 industrial engineering & automation ,Control and Systems Engineering ,Control theory ,0202 electrical engineering, electronic engineering, information engineering ,Feedback linearization ,Affine transformation ,Efficient energy use - Abstract
For a greenhouse temperature model with high non-linearity, strong uncertainties and varying parameters, a general framework for adaptive feedback linearization-based predictive controller design for indoor temperature system is presented. Firstly, a first-principle physical greenhouse temperature model is described and transferred to a standard affine non-linear system. Then, the well-known unscented Kalman filter is used for automatic, online estimation of parameter and state in the temperature model, which allows the control strategy to be applied in an adaptive way. In addition, based on the adaptive greenhouse temperature system, model predictive control with state feedback linearization is incorporated to address the reference deviation and energy consumption. At last, various simulation tests are applied to gain some insight into the performance of the developed approach as compared to the predictive control combining feedback linearization without the unscented Kalman filter estimation, resulting in the greenhouse temperature tracking root mean square errors as 1.0 °C and 1.2 °C, respectively. The simulation results show that the proposed approach can provide fast and accurate tracking of set points adaptively to time-varying phenomena and can improve the energy efficiency of the greenhouse temperature control.
- Published
- 2018
46. Greenhouse modelling and control based on T-S model
- Author
-
Chen Lijun, Liang Meihui, He Yaofeng, Du Shangfeng, and Qiao Xiaohui
- Subjects
Mathematical optimization ,Relation (database) ,Computer science ,020209 energy ,Greenhouse ,02 engineering and technology ,Fuzzy logic ,Set (abstract data type) ,Variable (computer science) ,Model predictive control ,Control and Systems Engineering ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Cluster analysis ,Membership function - Abstract
To resolve the problem that greenhouse climate is difficult to model and hard to control accurately, a method of greenhouse modelling and control was developed based on Takagi-Sugeno fuzzy model (T-S model). This method is divided into two parts. In the first part, T-S model would be built based on the historical data of greenhouse instead of the physical relation. During this process, membership function was built by c-means clustering which is used to cluster the variable of historical data. The result of clustering determines the composition of both antecedent and consequence of the T-S fuzzy rules, and the parameters of T-S rules would be solved by recursive weighted least squares algorithm. In the second part, model predictive control is adopted with 3 step predictive length. According to simulations, the proposed modelling and control method give good performance and the result close to the set value.
- Published
- 2018
47. The performance study of eco-friendly alkali-activated oil shale cementing materials for wastewater treatment structure
- Author
-
Chen LiJun, Ding Rui, and Jiang YinShan
- Subjects
Waste treatment ,Waste management ,Wastewater ,Environmental science ,Sewage treatment ,Water treatment ,Porosity ,Chemical composition ,Oil shale ,Environmentally friendly - Published
- 2018
48. Linear Quadratic Optimal Control Applied to the Greenhouse Temperature Hierarchal System
- Author
-
Du Shangfeng, Chen Lijun, Liang Meihui, and He Yaofeng
- Subjects
0209 industrial biotechnology ,Set point tracking ,Computer science ,Greenhouse ,02 engineering and technology ,Linear quadratic ,Linear quadratic optimal control ,Set (abstract data type) ,Reduction (complexity) ,020901 industrial engineering & automation ,Control and Systems Engineering ,Control theory ,Limit (music) ,0202 electrical engineering, electronic engineering, information engineering ,Hierarchical control system ,020201 artificial intelligence & image processing ,Affine transformation ,Layer (object-oriented design) - Abstract
Optimal greenhouse temperature management systems as hierarchical systems have been employed to achieve suitable conditions for crop growth. The system is generally decomposed into upper and lower layers. The lower layer usually includes online controllers that try to cancel tracking errors of temperature set points obtained from the upper layer. However, as the greenhouse temperature is highly non-linear, the problem of lower layer controller design becomes very complex and the online computational demands are great, which limit the practical applications of hierarchical systems. This paper presents the design of a practical greenhouse temperature hierarchical control approach. In lower layer, a linear quadratic optimal controller with heater inputs is used. The strategy is based on a linearised model achieved by using an accurate linearisation method for an inside temperature non-linear physical model which can be described as an affine non-linear one. The controller is designed by means of finding a tradeoff between set point tracking and cost requirements reduction. The upper layer calculates optimal temperature trajectories by minimising net costs. Performance of the hierarchical control system is studied in simulation. The results show that the upper layer controller can effectively achieve the set point and that the lower layer controller can contribute to a good control performance with a minor cost increment.
- Published
- 2018
49. Quantitative profiling of glycerides, glycerophosphatides and sphingolipids in Chinese human milk with ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry
- Author
-
Liu Qian, Tiemin Jiang, Junying Zhao, Hao Zhou, Nan Li, Tie Lin, Liu Yan, Chen Lijun, Juncai Hou, Kai Yang, Qiao Weicang, and Yuyang Zhao
- Subjects
China ,Spectrometry, Mass, Electrospray Ionization ,Glyceride ,Mass spectrometry ,01 natural sciences ,High-performance liquid chromatography ,Glycerides ,Analytical Chemistry ,0404 agricultural biotechnology ,Molecular level ,Pregnancy ,Humans ,Lactation ,Quadrupole time of flight ,Chromatography, High Pressure Liquid ,Phospholipids ,Sphingolipids ,Chromatography ,Milk, Human ,Chemistry ,010401 analytical chemistry ,04 agricultural and veterinary sciences ,General Medicine ,Polar lipids ,040401 food science ,Sphingolipid ,0104 chemical sciences ,Female ,Energy source ,Chromatography, Liquid ,Food Science - Abstract
Human milk lipids are an important energy source and essential nutrients for the growth and development of infants. The UPLC/Q-TOF-MS was used to qualitatively and quantitatively analyze human milk lipids. Totally, 411 species of lipids were identified, in which the content of OPL was generally higher than that of OPO; SM (75.38 mg/L, 40.39%), PE (51.12 mg/L, 27.39%) and PC (40.10 mg/L, 21.49%) had the highest contents among polar lipids, mainly including SM42:2:2 (22.24 mg/L), PE36:2 (C18:0-C18:2, 21.39 mg/L) and PC36:2 (C18:0-C18:2, 19.80 mg/L). In human milk, TAG56:7 (137.14 mg/L), TAG56:8 (59.49 mg/L), TAG58:8 (65.90 mg/L) and TAG58:9 (49.99 mg/L) were the main sources of AA and DHA; PE was an important source of AA and DHA in polar lipids; and linoleic acyl in glycerides and phospholipids had higher contents than other polyunsaturated fatty acyls. These results provided the scientific basis for the simulation of human milk at molecular level.
- Published
- 2021
50. The Belt and Road Initiative and Production Capacity Cooperation between China and India
- Author
-
Chen Lijun
- Subjects
Production (economics) ,Business ,China ,Agricultural economics - Published
- 2019
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