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A novel FeNi-Mo2C@SiO2 monolith electrocatalyst was constructed to boost the OER due to the increased number of active sites and enhanced intrinsic activity.

Purpose. Inflammation and apoptosis after spinal cord contusion (SCC) are important causes of irreversible spinal cord injury. Interleukin-1β (IL-1β) is a key inflammatory factor that promotes the aggravation of spinal cord contusion. However, the specific role and regulatory mechanism of IL-1β in spinal cord contusion is still unclear. Therefore, this study applied bioinformatics to analyze and mine potential gene targets interlinked with IL-1β, animal experiments and lentiviral interference technology were used to explore whether IL-1β affected the recovery of motor function in spinal cord contusion by interfering with PI3K/AKT1 signaling pathway. Method. This study used bioinformatics to screen and analyze gene targets related to IL-1β. The rat SCC animal model was established by the Allen method, and the Basso Beattie Bresnahan (BBB) score was used to evaluate the motor function of the spinal cord-injured rats. Immunohistochemistry and immunofluorescence were used to localize the expression of IL-1β and AKT1 proteins in spinal cord tissue. Quantitative polymerase chain reaction and Western blot were used to detect the gene and protein expressions of IL-1β, PI3K, and AKT1. RNAi technology was used to construct lentivirus to inhibit the expression of IL-1β, lentiviral interference with IL-1β was used to investigate the effect of IL-1β and AKT1 on the function of spinal cord contusion and the relationship among IL-1β, AKT1, and downstream signaling pathways. Results. Bioinformatics analysis suggested a close relationship between IL-1β and AKT1. Animal experiments have confirmed that IL-1β is closely related to the functional recovery of spinal cord contusion. Firstly, from the phenomenological level, the BBB score decreased after SCC, IL-1β and AKT1 were located in the cytoplasm of neurons in the anterior horn of the spinal cord, and the expression levels of IL-1β gene and protein in the experimental group were higher than those in the sham operation group. At the same time, the expression of AKT1 gene decreased, the results suggested that the increase of IL-1β affected the functional recovery of spinal cord contusion. Secondly, from the functional level, after inhibiting the expression of IL-1β with a lentivirus-mediated method, the BBB score was significantly increased, and the motor function of the spinal cord was improved. Thirdly, from the mechanistic level, bioinformatics analysis revealed the relationship between IL-1β and AKT1. In addition, the experiment further verified that in the PI3K/AKT1 signaling pathway, inhibition of IL-1β expression upregulated AKT1 gene expression, but PI3K expression was unchanged. Conclusion. Inhibition of IL-1β promotes recovery of motor function after spinal cord injury in rats through upregulation of AKT1 expression in the PI3K/AKT1 signaling pathway. Bioinformatics analysis suggested that IL-1β may affect apoptosis and regeneration by inhibiting the expression of AKT1 in the PI3K/AKT1 signaling pathway to regulate the downstream FOXO, mTOR, and GSK3 signaling pathways; thereby hindering the recovery of motor function in rats after spinal cord contusion. It provided a new perspective for clinical treatment of spinal cord contusion in the future.

BackgroundEarly detection of kidney diseases can be challenging as conventional methods such as blood tests or imaging techniques (computed tomography (CT), magnetic resonance imaging (MRI), or ultrasonography) may be insufficient to assess renal function. A single-photon emission CT (SPECT) renal scan provides a means of measuring glomerular filtration rates (GFRs), but its diagnostic accuracy is limited due to its planar imaging modality and semi-quantification property. In this study, we aimed to improve the accuracy of GFR measurement by preparing a positron emission tonometry (PET) tracer 68Ga-Ethylenediaminetetraacetic acid (68Ga-EDTA) and comprehensively evaluating its performance in healthy mice and murine models of renal dysfunction.MethodsDynamic PET scans were performed in healthy C57BL/6 mice and in models of renal injury, including acute kidney injury (AKI) and unilateral ureter obstruction (UUO) using 68Ga-EDTA. In a 30-min dynamic scan, PET images and time-activity curves (TACs) were acquired. Renal function and GFR values were measured using renograms and validated through serum renal function parameters, biodistribution results, and pathological staining.Results68Ga-EDTA dynamic PET imaging quantitatively captured the tracer elimination process. The calculated GFR values were 0.25 ± 0.02 ml/min in healthy mice, 0.01 ± 0.00 ml/min in AKI mice, and 0.25 ± 0.04, 0.29 ± 0.03 and 0.24 ± 0.01 ml/min in UUO mice, respectively. Furthermore, 68Ga-EDTA dynamic PET imaging and GFRPET were able to differentiate mild renal impairment before serum parameters indicated any changes.ConclusionsOur findings demonstrate that 68Ga-EDTA dynamic PET provides a reliable and precise means of evaluating renal function in two murine models of renal injury. These results hold promise for the widespread clinical application of 68Ga-EDTA dynamic PET in the near future.

We successfully fabricated a pure phase 2D perovskite single crystal BA2PbBr4. We applied it as a wafer in the field of X-rays imaging and showed good imaging performance impressive environmental and temperature stability.

Based on the panel data of China from 2003 to 2017, this paper applies the panel vector autoregressive (PVAR) model to the study of the influencing factors of carbon emissions. After the cross-section dependence test, unit root test and cointegration test of panel data, the dynamic relationship between energy consumption, economic growth, urbanization, financial development and CO2 emissions is investigated by using PVAR model. Then, we used the impulse response function tool to better understand the reaction of the main variables of interest, CO2 emissions, aftershocks on four factors. Finally, through the variance decomposition of all factors, the influence degree of a single variable on other endogenous variables is obtained. Overall, the results show that the four factors have a significant and positive impact on carbon emissions. In addition, variance decomposition also showed that energy consumption and economic growth strongly explained CO2 emissions. These results indicate that the financial, economic and energy sectors of China's provinces still make relatively weak contributions to reducing carbon emissions and improving environmental quality. Therefore, several policies are proposed and discussed.

The renin-angiotensin system (RAS) has been suggested to play an important role in cardiac remodeling after acute myocardial infarction (AMI). We have confirmed that bone marrow mesenchymal stem cell-derived exosomes (BMSC-EX) had similar types of repair like effects upon tissues as BMSC, but the mechanisms remain unknown. BMSC were cultured to the third generation and were induced to release exosomes. Rats were injected with exosomes (100 μg/mL) or stem cells (1 × 10

Objective To construct a prediction model for more precise evaluation of prognosis which will allow personalized treatment recommendations for adjuvant therapy in patients following resection of esophageal squamous cell carcinoma (ESCC). Background Marked heterogeneity of patient prognosis and limited evidence regarding survival benefit of various adjuvant therapy regimens pose challenges in the clinical treatment of ESCC. Methods Based on comprehensive clinical data obtained from 4,129 consecutive patients with resected ESCC in a high-risk region in China, we identified predictors for overall survival (OS) through a two-phase selection based on Cox proportional hazard regression and minimization of Akaike information criterion. The model was internally validated using bootstrapping and externally validated in 1,815 patients from a non-high-risk region in China. Results The final model incorporates nine variables: age, sex, primary site, T stage, N stage, number of lymph nodes harvested, tumor size, adjuvant treatment, and hemoglobin level. A significant interaction was also observed between N stage and adjuvant treatment. N1+ stage patients were likely to benefit from addition of adjuvant therapy as opposed to surgery alone, but adjuvant therapy did not improve OS for N0 stage patients. The C-index of the model was 0.729 in the training cohort, 0.723 after bootstrapping, and 0.695 in the external validation cohort. This model outperformed the seventh edition American Joint Committee on Cancer staging system in prognostic prediction and risk stratification. Conclusion The prediction model constructed in this study may facilitate precise prediction of survival and inform decision-making about adjuvant therapy according to N stage.

This paper aims to study the decoupling status and emission reduction potential of China's petrochemical industry from 1996 to 2019. Firstly, the IPCC method is used to calculate the CO

The traditional particle swarm optimization algorithm is fast and efficient, but it is easy to fall into a local optimum. An improved PSO algorithm is proposed and applied in 3D path planning of UAV to solve the problem. Improvement methods are described as follows: combining PSO algorithm with genetic algorithm (GA), setting dynamic inertia weight, adding sigmoid function to improve the crossover and mutation probability of genetic algorithm, and changing the selection method. The simulation results show that the improved PSO algorithm solves better route results and is faster and more stable.

Artificial Intelligence (AI) is deemed to be the commanding point of science and technology in the next era. In recent years, with the enhancement of computer computing power, the improvement of the quantity and quality of big data, and the important breakthroughs in many research fields such as machine learning and speech recognition, AI technology has developed rapidly and has been widely used in all walks of life. In the financial industry, the application of AI technology in risk control, marketing, customer service, transaction, operation, and product optimization of financial institutions is becoming increasingly mature, and some new business models have been created. Starting from the application status and significance of AI in the international financial field, this paper expounds on the application, status quo, and development trend of AI in the financial industry. Then, in view of the risks and practical challenges existing in the development process of AI, based on the reality of international financial development, this paper summarizes the measures to promote the in-depth, healthy, and sustainable development of AI in the financial market. This paper aims to let readers understand the development status of AI in the financial field, and also provide theoretical reference for scholars in this field.

Metal-free perovskites are of interest for their chemical diversity and eco-friendly properties, and recently have been used for X-ray detection with superior carrier behavior. However, the size and shape complexity of the organic components results in difficulties in evaluating their stability in high-energy radiation. Herein, we introduce multiple hydrogen-bond metal-free PAZE-NH

ObjectivesUpper gastrointestinal (G.I.) cancer screening has been conducted in China for decades. However, the economic burden for treatment “intensively” occurred in advance due to screening in resource-limited communities remain unclear.MethodsWe compared the treatment costs for upper G.I. cancers from the screening and control arms of a population-based randomized trial in a high-risk area for esophageal cancer (EC) in China based on claims data from the health insurance system in the local area which included whole population coverage.ResultsThe average out-of-pocket cost per treatment of EC in the screening arm was lower than that in the control arm ($5,972vs.$7,557). This difference was a consequence of down-staging from screening which resulted in lower cost therapy for earlier stage cancers. Moreover, this result is similar for cardial and non-cardial gastric cancer in the two study arms ($7,933vs.$10,605). However, three times as many (103vs.36) families in the screening arm suffered catastrophic health expenditure for all cancer types. The overall treatment cost for all EC patients in the screening arm ($1,045,119) was 2.44 times that in the control arm ($428,292), and the ratio for cardial and non-cardial gastric cancer was 1.12 ($393,261vs.$351,557).ConclusionCancer treatment secondary to screening may triple the likelihood of catastrophic patient medical expenditure, and sharply increase the economic pressure on the local community, particularly for cancer types which are of high prevalence. Financial support for patients and the health insurance system should be taken into consideration when planning budgets for cancer screening programs in communities which are resource-limited.

Wide bandgap (WBG) devices allow power factor correction (PFC) circuits to operate at megahertz (MHz), which improves power density. In low-power applications, critical conduction mode (CrM) boost PFC circuits are widely used due to its simple structure and minimized turn-on loss. Compared with the kilohertz (kHz) operation, MHz PFC in CrM yields larger inductor valley current during the zero voltage or valley switching turn-on, and significant grid current zero-crossing distortion, both of which are not considered in conventional PFC behavioral models. As a result, the conventional PFC design tool shows substantial inaccuracy in the estimation of switching frequency, inductor current envelopes, and power loss. This article analyzes these issues and proposes an improved power loss model to aid the design of MHz CrM PFC. Experimental results are presented to validate the accuracy.

Efficient solar energy capture and utilization is of great importance in various photoenergy conversion systems, such as solar cells and photocatalysts. Herein, we reported a photocatalytic enhancement system by constructing a nanocavity structure with a carrier-selective layer. The photocatalytic hydrogen production activity is improved by ∼13.8 times in comparison to that of Au/CdS due to the construction of a nanocavity structure with a carrier-selective layer, in which the nanocavity structure is mainly used to enhance the utilization efficiency for solar light in the photocatalytic system. The Au–S layer on the one hand effectively transfers the holes, which extends the lifetime of the active species in the semiconductor photocatalyst to accelerate the hydrogen production reaction. On the other hand, it changes the electron transfer pathway between CdS and Au nanoparticles. This system achieved an optimal H2-evolution rate of 0.55 mmol h−1 under visible light irradiation, and its apparent quantum efficiency (AQE) reached 19.1% at 430 nm. As a novel strategy, our study may provide a new design protocol for highly efficient photocatalytic systems.

To evaluate the long-term and short-term outcomes of minimally invasive esophagectomy (MIE) compared with open esophagectomy (OE) in localized esophageal squamous cell carcinoma (ESCC) patients in real-world settings.MIE is an alternative to OE, despite the limited evidence regarding its effect on long-term survival.We recruited 5822 consecutive patients with resectable ESCC in two typical high-volume centers in southern and northern China, 1453 of whom underwent MIE. Propensity score-based overlap weighted regression adjusted for multifaceted confounding factors was used to compare outcomes in the MIE and OE groups.Five-year overall survival (OS) was 62.7% in the MIE group and 57.7% in the OE group. The overlap weighted Cox regression showed slightly better OS in the MIE group (HR 0.93, 95% CI: 0.82-1.06). Although duration of surgery was longer and treatment cost higher in the MIE group than in the OE group, the number of lymph nodes harvested was larger, the proportion of intraoperative blood transfusions lower, and postoperative complications less in the MIE group. 30-day (RR 0.77, 0.38-1.55) and 90-day (RR 0.79, 0.46-1.35) mortality were lower in the MIE group versus the OE group, although not statistically significant. These findings were consistent across different analytic approaches and subgroups, notably in the subset of ESCC patients with large tumors.MIE can be performed safely with OS comparable to OE for patients with localized ESCC, indicating MIE may be recommended as the primary surgical approach for resectable ESCC in health facilities with requisite technical capacity.

LBA661 Background: Liposomal irinotecan administered with 5-fluorouracil/leucovorin (5-FU/LV) is approved in the USA and Europe for mPDAC following progression with gemcitabine-based therapy. A phase 1/2 study (Wainberg et al. Eur J Cancer 2021;151:14–24; NCT02551991) demonstrated promising anti-tumor activity in patients with mPDAC who received first-line liposomal irinotecan 50 mg/m2 + 5-FU 2400 mg/m2 + LV 400 mg/m2 + oxaliplatin 60 mg/m2 (NALIRIFOX). Herein, we present results from NAPOLI-3 (NCT04083235), a randomized, open-label, phase 3 study investigating the efficacy and safety of NALIRIFOX compared with nab-paclitaxel + gemcitabine as first-line therapy in patients with mPDAC. Methods: Eligible patients with histopathologically/cytologically confirmed untreated metastatic PDAC were randomized (1:1) to receive NALIRIFOX on days 1 and 15 of a 28-day cycle or nab-paclitaxel 125 mg/m2 + gemcitabine 1000 mg/m2 (Gem+NabP) on days 1, 8 and 15 of a 28-day cycle. Randomization was stratified by ECOG performance status, geographic region and presence or absence of liver metastases. The primary endpoint was overall survival (OS); secondary endpoints were progression-free survival (PFS), overall response rate (ORR) and safety. OS was evaluated when ≥ 543 events were observed using a stratified log-rank test with an overall 1-sided significance level of 0.025. Results: Overall, 770 patients (NALIRIFOX, n = 383; Gem+NabP, n = 387) were included. Baseline characteristics were well balanced between arms. At a median follow-up of 16.1 months, 544 events had occurred. The median OS was 11.1 months in the NALIFIROX arm as compared with 9.2 months in the Gem+NabP arm (HR 0.84 [95% CI 0.71–0.99]; p = 0.04); PFS was also significantly improved (7.4 months vs 5.6 months; HR 0.70 [0.59–0.84]; p = 0.0001). Grade 3/4 treatment-emergent adverse events (TEAEs) with ≥ 10% frequency in patients receiving NALIRIFOX versus Gem+NabP included diarrhea (20.3% vs 4.5%), nausea (11.9% vs 2.6%), hypokalemia (15.1% vs 4.0%), anemia (10.5% vs 17.4%) and neutropenia (14.1% vs 24.5%). Conclusions: First-line NALIRIFOX demonstrated clinically meaningful and statistically significant improvement in OS and PFS compared with Gem+NabP in treatment-naïve patients with mPDAC. The safety profile of NALIRIFOX was manageable and consistent with the profiles of the treatment components. Funding: Funded by Ipsen. Clinical trial information: NCT04083235 .[Table: see text]

The purpose of this paper is to study the influencing factors of the ecological pressure of the energy carbon footprint (EPECF) of China's whole industry from 2000 to 2018. First, the EPECF of 48 sub industries is calculated, then divides 48 sub-industries into high-, medium-, and low-pressure industries, and uses the logarithmic mean Divisia index (LMDI) method to analyze and summarize the main driving forces of China's industrial EPECF changes. Finally, policy suggestions for the future industrial decompression are put forward. The main results are as follows: (1) Economic development is the most important factor to promote the growth of EPECF of the three major industries. (2) At present, the population pressure factors of forest and grassland have little effect, and the effect of returning farmland to forest and grassland has not been truly played. (3) The adjustment of industrial structure has gradually become a key factor in reducing EPECF of the three industries. (4) The gradual stability of energy intensity has a certain inhibitory effect on the increase of EPECF in high-pressure industry. (5) The adjustment of energy structure in low-pressure industry has gradually worked. Therefore, the government should establish an economic sustainable development system, vigorously develop clean energy, and realize the green transformation of various industries. This provides an empirical example for other countries in the world to reduce the EPECF.

High-performance X-ray detectors have immense potential in medical and security inspections. However, the current X-ray detectors are limited in flexible, high-spatial-resolution large-scale detection, and integration for imaging. Here, nuclear track-etched porous polyethylene terephthalate (PET) is developed as the template for preparing uniform, large-area (≥10

The paper first summarizes the path planning, then divides the path planning algorithm suitable for UAV into global path planning and local path planning in continuous domain. According to the related algorithms, the background, design ideas, advantages and disadvantages are summarized. Finally, the prospect of the development direction of future research.

Oxygen vacancies (O

A novel core-shell magnetic Prussian blue-coated Fe3O4 composites (Fe3O4@PB) were designed and synthesized by in-situ replication and controlled etching of iron oxide (Fe3O4) to eliminate Cd (II) from micro-polluted water. The core-shell structure was confirmed by TEM, and the composites were characterized by XRD and FTIR. The pore diameter distribution from BET measurement revealed the micropore-dominated structure of Fe3O4@PB. The effects of adsorbents dosage, pH, and co-existing ions were investigated. Batch results revealed that the Cd (II) adsorption was very fast initially and reached equilibrium after 4 h. A pH of 6 was favorable for Cd (II) adsorption on Fe3O4@PB. The adsorption rate reached 98.78% at an initial Cd (II) concentration of 100 μg/L. The adsorption kinetics indicated that the pseudo-first-order and Elovich models could best describe the Cd (II) adsorption onto Fe3O4@PB, indicating that the sorption of Cd (II) ions on the binding sites of Fe3O4@PB was the main rate-limiting step of adsorption. The adsorption isotherm well fitted the Freundlich model with a maximum capacity of 9.25 mg·g−1 of Cd (II). The adsorption of Cd (II) on the Fe3O4@PB was affected by co-existing ions, including Cu (II), Ni (II), and Zn (II), due to the competitive effect of the co-adsorption of Cd (II) with other co-existing ions.

68Ga-radiolabeled small molecules that specifically target prostate specific membrane antigen (PSMA) has been extensively investigated, and some of those tracers have been used in diagnosis of prostate cancer with 68Ga-positron emission tomography (68Ga-PET). Nevertheless, current 68Ga-labeled radiotracers show fair detection rates to metastasized prostate cancer lesions, especially to those with lower level of prostate specific antigen (PSA), which often occur in biochemical recurrence of prostate cancer. The goal of this study was to design and synthesize a new PSMA-targeted radiotracer 68Ga-SC691 with high affinity to prostate cancer cells and excellent pharmacokinetics. To this end, structural optimum was made on the bifunctional group, target motif, and linker while high affinity targeting scaffold was remained. In order to explore its potential in clinical, a comparative study was further performed in vitro and in vivo between 68Ga-SC691 and 68Ga-PSMA-11, the clinically approved tracer for PSMA-positive prostate cancer. SC691 was radiolabeled to provide 68Ga-SC691 in 99% radiolabeling yield under mild conditions. High uptake and internalization ratio into LNCaP cells were observed in in vitro studies. In vivo studies showed that 68Ga-SC691 had a favorable biodistribution property and can specifically accumulate on PSMA-positive LNCaP xenografts visualized by micro-PET/CT. This radiotracer showed excellent PET imaging quality and comparable uptake at LNCaP xenografts if not higher than 68Ga-PSMA-11.

68Ga-radiolabeled small molecules that specifically target prostate-specific membrane antigen (PSMA) have been extensively investigated, and some of these tracers have been used in the diagnosis of prostate cancer via 68Ga-positron emission tomography (68Ga-PET). Nevertheless, current 68Ga-labeled radiotracers show only fair detection rates for metastatic prostate cancer lesions, especially those with lower levels of prostate specific antigen (PSA), which often occurs in the biochemical recurrence of prostate cancer. The goal of this study was to design and synthesize a new PSMA-targeted radiotracer, 68Ga-SC691, with high affinity for prostate cancer cells and excellent pharmacokinetics. To this end, structural optimization was carried out on the bifunctional group, target motif, and linker while the high affinity targeting scaffold remained. To explore its potential in the clinic, a comparative study was further performed in vitro and in vivo between 68Ga-SC691 and 68Ga-PSMA-11, a clinically approved tracer for PSMA-positive prostate cancer. SC691 was radiolabeled to provide 68Ga-SC691 in 99% radiolabeling yield under mild conditions. High uptake and a high internalization ratio into LNCaP cells were observed in in vitro studies. In vivo studies showed that 68Ga-SC691 had favorable biodistribution properties and could specifically accumulate on PSMA-positive LNCaP xenografts visualized by micro-PET/CT. This radiotracer showed excellent PET imaging quality and comparable, if not higher, uptake in LNCaP xenografts than 68Ga-PSMA-11.

The analysis of user behavior provides a large amount of useful information. After being extracted, this information is called user knowledge. User knowledge plays a guiding role in implementing user-centric updates for software platforms. A good representation and application of user knowledge can accelerate the development of a software platform and improve its quality. This paper aims to further the utilization of user knowledge by mining the user knowledge that is implicit in user behavior and then constructing a knowledge graph of this behavior. First, the association between a software bug and a software component is mined from the user knowledge. Then, the knowledge entity extraction and relationship extraction are performed from the development code and the user behavior. Finally, the knowledge is stored in the graph database, from which it can be visually retrieved. Relevant experiments on CIFLog, an integrated logging processing software platform, have proved the effectiveness of this research. Constructing a user behavior knowledge graph can improve the utilization of user knowledge as well as the quality of software platform development.

Previous risk prediction models taking esophageal malignant lesions detected during endoscopy as the primary outcome are not always sufficient to identify prevalent cases which are "overlooked" at screening. We aimed to update and externally validate our previous risk prediction model for malignant esophageal lesions by redefining the predicted outcome.15,192 individuals from the Endoscopic Screening for Esophageal Cancer in China randomized controlled trial (ESECC trial, NCT01688908) were included as the training set, and 4576 participants from another population-based esophageal squamous cell carcinoma (ESCC) screening cohort (Anyang Esophageal Cancer Cohort Study, AECCS) served as the external validation set. Lesions with severe dysplasia or worse diagnosed at chromoendoscopy or identified via follow-up within 1 year after screening were defined as main outcome. Logistic regressions were applied to reconstruct the questionnaire-based prediction model using information collected before screening, with Akaike Information Criterion to determine the model structure.The final prediction model included age and its quadratic term, family history of ESCC, low body mass index (≤22 kg/mThe described tool may promote the efficiency of current national screening programs for ESCC and contribute to a precision screening strategy in high-risk regions in China.This work was supported by the National Natural Science Foundation of China (82073626, 81773501), the National ScienceTechnology Fundamental Resources Investigation Program of China (2019FY101102), the National Key RD Program of China (2021YFC2500405), the Beijing-Tianjin-Hebei Basic Research Cooperation Project (J200016), the Digestive Medical Coordinated Development Center of Beijing Hospitals Authority (XXZ0204) and the Beijing Nova Program (Z201100006820093). Sponsors had no role in the study design, data collection, analysis, and interpretation of data.

The identification of sandstone contrasting layers is a key step in the depth calibration of sandstone horizons, whose errors can cause large deviations in positioning results, which in turn affect subsequent drilling and production of oil wells. The identification of a sandstone contrast layer is calculated based on distinct response characteristics of well logging curves in the depth range of the layer. The identification of features of a well logging curve is generally made using the axial geological signals centered on the depth, combined with a time series similarity analysis of the data. However, when the local morphological features indicated and described by the curves corresponding to the depth of the sandstone reservoir are distinctly different, there will be differences in the features to obtained. To improve the accuracy in extracting similar features from well logging curves, we propose a similarity measurement method based on morphological characteristics to comprehensively analyze three morphological features of the curve sequence: the segmentation trend, fluctuation amplitude, and depth span. The similarity of the subsequence is measured according to the weighted slope difference of the comparative sequences. The method treats the attributes of similar waveform characteristics as a whole, which can overcome the shortcomings of conventional time series methods in describing the degree of morphological changes of the curves. Results from processing experimental data show that compared with the conventional method, the proposed method can effectively improve the accuracy in extracting the features of well logging curves and identifying the sandstone contrast layer.

Environmentally stable, low cost, large stokes shift, adjustable area and flexibility are basic factors to prepare scintillator films for their commercial application. Here, a low cost (∼3 $/g) room-temperature ligand-assisted reprecipitation method is used to synthesize one-dimensional crystal structure based on Rb2CuX3 (X = Br, Cl). Rb2CuBr3 exhibits quite high mass yield of 90% with high Photoluminescence quantum yield (PLQY) of 59.06%. Importantly, its bright blue emission (90 nm stokes shift) is consistent with the highest optical detection efficiency wavelength range of commercial SiPM. Further characterizations point out that such effective blue emission comes from the recombination of excitons rather than the defects or combination of electron-hole pairs. And the existing strong exciton-photon coupling is conducive to the formation of self-trapped excitons (STEs). Finally, uniform and adjustable area Rb2CuBr3-polystyrene composite films have been successfully obtained. It's fascinating that the films exhibit ultra-flexibility (unchanged performance after multiple bending of 400 times) and excellent stability (subtle attenuation after 30 days of storage in a harsh environment). As an X-ray imaging screen, it presents a sensitive scintillation response to X-ray signals with superior linearity with high-quality images. Therefore, our prepared Rb2CuBr3 scintillator shows great commercial prospects in the field of flexible X-ray detection.

Dense and fine-grained boron carbide (B4C) ceramics were fabricated via high-pressure hot pressing (100 MPa) using powders, which are prepared by high-energy ball milling. These powders were sintered at a low temperature (1800 °C) without any sintering aid. The dense and fine-grained B4C ceramics demonstrate super high hardness, outstanding fracture toughness and modern flexure strength. The milled powders were characterised by disordered crystal structure and ultrafine particle size that ranges from a few nanometres to a few hundred nanometres. The combined contributions of high pressure and the characteristic of the milled powders guaranteed that the dense fine-grained microstructure was achieved at only 1800 °C. The grain size distribution of the ceramics was inhomogeneous and ranged from 70 nm to 1.6 µm. However, the average grain size was fine at only 430 nm, which partially contributed to the super high hardness of the B4C ceramics. The locally concentrated areas of the small grains changed the fracture mode of the B4C ceramics from the complete transgranular fracture to a mixture of transgranular and intergranular fractures, thereby enhancing the toughness of the B4C ceramics. The relative density, Vickers hardness, flexure strength and fracture toughness of the obtained B4C ceramics reached up to 99.5%, 41.3 GPa, 564 MPa and 4.41 MPa m1/2, respectively.

With offline single-phase power supplies moving toward the megahertz switching frequency range, the converter's bus capacitor becomes the bottleneck of further improvement of power density. Partial constant power operation is effective in reducing the bus capacitance and capacitor current stress for low-power applications. However, its impact on circuit design and operation design has not been studied thoroughly. With the developed circuit operation and loss model, this paper presents design considerations and power loss analysis of megahertz ac/dc converters in partial constant power operation. An adaptive constant power control is also proposed, based on the developed models, to improve the light-load efficiency and power factor. A 65 W, megahertz critical conduction mode GaN-based ac/dc converter prototype has been developed to validate the analysis and circuit operation method. Compared with power factor correction (PFC) operation, partial constant power control exhibits an efficiency drop of less than 1%. However, a 50% reduction of bus capacitance can be realized. With the proposed adaptive constant power control, the light-load efficiency and power factor can be improved to be a level similar to the PFC operation. This paper ends with a discussion of the possibility of extending the proposed operation method to higher power applications.

Ultrafine-grained boron carbide ceramics with ultrahigh hardness were fabricated via a unique combination of high-energy ball milling and self-propagating high-temperature synthesis plus quick pressing (SHS/QP) method. Results show that ultrafine powders obtained by milling possess a disordered character. During the SHS/QP, the tiny particles in the milled powders are integrated into neighbouring large particles to form ceramic grains. The average grain size of the ceramics is approximately 290 nm. After SHS/QP, a few amorphous areas and high-density defects were still observed in ceramics. The ceramics possess high relative density (approximately 99.2%) and ultrafine grain (approximately 290 nm) but with a weak degree of crystallinity which weakens hardness. Heat treatment can improve crystallinity while maintaining the ultrafine grain of the ceramics, thereby increasing the hardness of the ceramics from 31 GPa to 40 GPa.