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Protective effects of baffles with different positions,row spacings,heights on debris flow impact

Journal of Mountain Science 2024年第7期21卷 2352-2367页

作者： SUN Xinpo CHEN Min BI Yuzhang ZHENG lu CHE Chi XU Ao TIAN Zijian jiang Zheyuan College of Civil Engineering Sichuan University of Science and EngineeringZigong 643000China College of Resources and Environment Fujian Agriculture and Forestry UniversityFuzhou 350002China School of Civil Engineering Fuzhou UniversityFuzhou 350108China jiangsu Key Laboratory of Urban Underground Engineering&Environmental Safety Institute of Geotechnical EngineeringSoutheast UniversityNanjing 210096China Beijing Urban Construction Science Technology Promoting Association Beijing 100055China SUSE-BZ Geoenvironmental Engineering Joint Laboratory Sichuan University of Science and EngineeringZigong 643000China

The baffle effectively slowed down debris flow velocity,reduced its kinetic energy,and significantly shortened the distance of debris flow ***,they are widely used for protection against natural hazards such as landslides and *** study,based on the threedimensional DEM(Discrete Element Method),investigated the impact of different baffle positions on debris flow *** flow velocity and kinetic energy variations were studied through single-factor *** baffle positions were preliminarily selected by analyzing the influence of the first-row baffle position on the impact force and accumulation mass of debris ***,based on the selected baffle positions and four factors influencing the effectiveness of baffle protection(baffle position(P),baffle height(h),row spacing(S_(r)),and angle of transit area(α)),an orthogonal design was employed to further explore the optimal arrangement of *** research results indicate that the use of a baffle structure could effectively slow down the motion velocity of debris flows and dissipate their *** the baffle is placed in the transit area,the impact force on the first-row baffle is greater than that when the baffle is placed in the deposition ***,when the baffle is placed in the transit area,the obstruction effect on debris flow mass is also greater than that when the baffle is placed in the deposition *** orthogonal experimental range analysis,when the impact on the first row of baffles is used as the evaluation criterion,the importance of each influencing factor is ranked asα>P>S_(r)>*** the mass of debris flow behind the baffle is regarded as the evaluation criterion,the rank is changed to P>α>S_(r)>*** experimental simulation results show that the optimal baffle arrangement is:P_(5),S_(r)=16,α=35°,h=9.

关键词： Debris flow Baffle Protective effect Discrete element

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Mechanical robust and self-healing flexible perovskite solar cells with efficiency exceeding 23%

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Science China Chemistry 2024年第8期67卷 2670-2678页

作者： Yaohua Wang Ruikun Cao Yuanyuan Meng Bin Han Ruijia Tian Xiaoyi lu Zhenhua Song Shuncheng Yang Congda lu chang Liu Ziyi Ge College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310014China Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices Ningbo Institute of Materials TechnologyEngineeringChinese Academy of SciencesNingbo 315201China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences Beijing 100049China

Flexible perovskite solar cells(f-PSCs) have experienced rapid advancements due to the light-weight, flexibility, and solution processability of the perovskite materials, which prompted the power conversion efficiency(PCE) to 24.08%. However, f-PSCs still face challenges in terms of mechanical and environmental stability. This is primarily due to their inherent brittleness, the presence of residual tensile strain, and the high density of defects along the boundaries of perovskite grains. To this end, we carefully developed a cross-linkable elastomers 3-[(3-acrylamidopropyl)dimethylammonium] propanoate(ADP) with electrostatic dynamic bond, which could be in-situ cross-linked and coordinate with [Pb I6]4-to regulate the crystallization process of perovskite. The cross-linked elastomers attached to the perovskite grain boundaries could release the remaining tensile strains and mechanical stresses, leading to enhanced stability and flexibility of the f-PSCs. More importantly, the electrostatic interaction between positive and negative groups of cross-linked elastomers and hydrogen bond formation between N–H and C=O accelerate the cross-linking of ADP, endowing the flexible perovskite films with self-healing ability under mild treating conditions(60 °C for 30 min). As a result, the device achieves a remarkable PCE of 23.53%(certified 23.16%). Additionally, the device exhibits impressive mechanical sustainability and durability, retaining over 90% of initial PCE even after undergoing8,000 bending cycles.

关键词： Mechanical robust and self-healing flexible perovskite solar cells with efficiency exceeding 23

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Reliability evaluation of IGBT power module on electric vehicle using big data

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Journal of Semiconductors 2024年第5期45卷 50-60页

作者： Li Liu Lei Tang Huaping jiang Fanyi Wei Zonghua Li changhong Du Qianlei Peng Guocheng lu The School of Electrical Engineering Chongqing UniversityChongqing 400044China The Deepal Automobile Technology Co. Ltd.Chongqing 400023China

There are challenges to the reliability evaluation for insulated gate bipolar transistors(IGBT)on electric vehicles,such as junction temperature measurement,computational and storage *** this paper,a junction temperature estimation approach based on neural network without additional cost is proposed and the lifetime calculation for IGBT using electric vehicle big data is *** direct current(DC)voltage,operation current,switching frequency,negative thermal coefficient thermistor(NTC)temperature and IGBT lifetime are *** the junction temperature(T_(j))is *** the rain flow counting method,the classified irregular temperatures are brought into the life model for the failure *** fatigue accumulation method is then used to calculate the IGBT *** solve the limited computational and storage resources of electric vehicle controllers,the operation of IGBT lifetime calculation is running on a big data *** lifetime is then transmitted wirelessly to electric vehicles as input for neural *** the junction temperature of IGBT under long-term operating conditions can be accurately estimated.A test platform of the motor controller combined with the vehicle big data server is built for the IGBT accelerated aging ***,the IGBT lifetime predictions are derived from the junction temperature estimation by the neural network method and the thermal network *** experiment shows that the lifetime prediction based on a neural network with big data demonstrates a higher accuracy than that of the thermal network,which improves the reliability evaluation of system.

关键词： IGBT junction temperature neural network electric vehicles big data

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Impact of ursodeoxycholic acid therapy in autoimmune liver disease patients with COVID-19 and its clinical prognosis

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Biosafety and Health 2024年第3期6卷 165-170页

作者： Minghui Li Weihua Cao Tingting jiang Wen Deng Shiyu Wang Shuling Wu lu Zhang Yao lu Min chang Ruyu Liu Xiaoyan Ding Ge Shen Yuanjiao Gao Hongxiao Hao Xiaoxue Chen Leiping Hu Mengjiao Xu Yuyong jiang Wei Yi Yao Xie Rui Song Department of Hepatology Division 2 Beijing Ditan HospitalCapital Medical UniversityBeijing 100015China Department of Hepatology Division 2 Peking University Ditan Teaching HospitalBeijing 100015China Department of Medical Oncology Beijing Ditan HospitalCapital Medical UniversityBeijing 100015China Center of Integrative Medicine Beijing Ditan HospitalCapital Medical UniversityBeijing 100015China Department of Gynecology and Obstetrics Beijing Ditan HospitalCapital Medical UniversityBeijing 100015China Department of Infectious Disease Beijing Ditan HospitalCapital Medical UniversityBeijing 100015China

To explore the impact of ursodeoxycholic acid(UDCA)on severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection and clinical outcomes in patients with autoimmune liver disease(AILD).Patients diagnosed with AILD were enrolled and divided into a UDCA group and a non-UDCA group based on whether they received UDCA *** data were collected regarding AILD diagnosis,treatment,biochemical indicators,and imaging *** incidence of SARS-CoV-2 infection and the prognosis of AILD patients were observed.A total of 1,138 patients completed *** usage rate of hormone(P=0.003)and immunosuppressant(P=0.001)used for treating AILD in the non-UDCA group was markedly lower than in the UDCA *** UDCA usage rate was markedly lower in SARS-CoV-2 infected patients than in uninfected patients(P=0.003).The rate of SARS-CoV-2 infection in the non-UDCA group was significantly higher than in the UDCA group(P=0.018).Logistic regression analysis showed that UDCA use(P=0.003)was correlated to a lower incidence of SARS-CoV-2,while immunosuppressant use(P=0.017)increased the *** time from SARS-CoV-2 infection was markedly longer for those receiving UDCA treatment than those in the non-UDCA group(P=0.018).UDCA is associated with low SARS-CoV-2 incidence in AILD patients,while immunosuppressant increases its incidence *** receiving UDCA treatment have a longer recovery time after being infected.

关键词： Ursodeoxycholic acid(UDCA) Autoimmune liver disease(AILD) Coronavirus disease 2019(COVID-19) Primary biliary cholangitis(PBC) Autoimmune hepatitis(AIH)

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Cholecystokinin and cholecystokinin-A receptor: An attractive treatment strategy for biliary dyskinesia?

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World Journal of Gastroenterology 2024年第3期30卷 283-285页

作者： Jun chang Yan Liu Ting-Can jiang Lan Zhao Jian-Wei Liu Tianjin Institute of Acupuncture and Moxibustion The First Teaching Hospital of Tianjin University of Traditional Chinese MedicineTianjin 300381China Department of Gastroenterology Tianjin Hospital of Integrated Traditional Chinese and Western Medicine Nankai HospitalTianjin 300100China State Key Laboratory of Component-Based Chinese Medicine Tianjin University of Traditional Chinese MedicineTianjin 301617China School of Integrative Medicine Tianjin University of Traditional Chinese MedicineTianjin 301617China

Biliary dyskinesia is a relatively common gastrointestinal disease that is increas-ing in incidence as living standards ***,its underlying pathogenesis remains unclear,hindering the development of therapeutic ***,“Expression and functional study of cholecystokinin-A receptors on the interstitial Cajal-like cells of the guinea pig common bile duct”demonstrated that cholecystokinin(CCK)regulates the contractile function of the common bile duct through interaction with the CCK-A receptor in interstitial Cajal-like cells,contributing to improving the academic understanding of biliary tract dynamics and providing emerging directions for the pathogenesis and clinical management of biliary *** letter provides a brief overview of the role of CCK and CCK-A receptors in biliary dyskinesia from the perspective of animal experiments and clinical studies,and discusses prospects and challenges for the clinical application of CCK and CCK-A receptors as potential therapeutic targets.

关键词： Cholecystokinin Cholecystokinin-A receptor Biliary dyskinesia Interstitial Cajal-like cell Therapeutic target

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Research Progress in Enantioselective Radical Desymmetrization Reactions

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CCS Chemistry 2024年第7期6卷 1612-1627页

作者： chang-jiang Yang Lin Liu Qiang-Shuai Gu Xin-Yuan Liu Department of Chemistry and Dongguan Key Laboratory for Data Science and Intelligent Medicine Great Bay UniversityDongguan 523000 Shenzhen Grubbs Institute Department of Chemistryand Guangming Advanced Research InstituteSouthern University of Science and TechnologyShenzhen 518055 Academy for Advanced Interdisciplinary Studies and Department of Chemistry Southern University of Science and TechnologyShenzhen 518055

Enantioselective radical desymmetrization is a highly effective approach for rapidly creating enantioenriched molecules,introducing dramatically increased structural complexity from readily available prochiral or meso compound *** strategic modes have been developed for these reactions,which differ in the nature of the stereo-determining *** first category deals primarily with the stereoselective desymmetrization of closed-shell radical precursors or functional reagents,whereas the second category achieves desymmetrization by stereoselectively functionalizing open-shell radical *** mini-review explores the research progress in this growing field,aiming to elucidate mechanistic scenarios related to stereochemical ***,it offers insights into the challenges and opportunities that lie ahead for further development.

关键词： radical desymmetrization enantioselective desymmetrization radical functionalization transition metal catalysis asymmetric catalysis

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Nano polystyrene microplastics could accumulate in Nile tilapia(Oreochromis niloticus):Negatively impacts on the intestinal and liver health through water exposure

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Journal of Environmental Sciences 2024年第3期137卷 604-614页

作者： Di Wu Xing lu Li-Xue Dong Juan Tian Jin Deng Lei Wei Hua Wen Shan Zhong Ming jiang School of Basic Medical Sciences Wuhan UniversityWuhan 430071China Key Laboratory of Freshwater Biodiversity Conservation Ministry of Agriculture and Rural AffairsYangtze River Fisheries Research InstituteChinese Academy of Fishery SciencesWuhan 430223China Hubei Province Key Laboratory of Allergy and Immunology Wuhan 430071China

Microplastics(MPs)have become a significant concern for their potential ***,the correlation between the size of plastic particles and their toxicity remains ***,we investigate the toxic effects of different sizes(80 nm,800 nm,8μm and 80μm)polystyrene MPs(PS-MPs)on the model organism Nile tilapia(Oreochromis niloticus).The results of bioluminescent imaging indicate that the 80 nm PS-MPs are more likely to invade the body.H&E staining shows severe damage on the intestinal villi and distinct hepatic steatosis in the 80 nm *** U labeling shows that the proliferation activity of intestinal and liver cells reduces significantly in the 80 nm *** gut microbiome analysis shows a severe imbalance of gut microbiota homeostasis in the 80 nm *** analysis of liver transcriptomics and metabolomics shows that the liver lipid metabolism is disordered in the 80 nm *** conclusion,this study confirms that the 80 nm PS-MPs are more likely to induce intestinal and liver *** the above lay the foundation for further study on the pathological damage of MPs to other organisms.

关键词： Microplastics(MPs) Intestinal toxicity Liver toxicity Gut microbiome Lipid metabolism

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Ultra-high-temperature application of MXene: Stabilization of 2D Ti_(3)C_(2)T_(x) for cross-scale strengthening and toughening of 3D TiC

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Journal of Advanced Ceramics 2024年第1期13卷 1-10页

作者： lu Liu Guobing Ying Quanguo jiang Dong Wen Peng Wang Meng Wu Ziying Ji Yongting Zheng Xiang Wang Department of Materials Science and Engineering College of Mechanics and MaterialsHohai UniversityNanjing 211100China Key Laboratory of Superlight Materials&Surface Technology Ministry of EducationHarbin Engineering UniversityHarbin 150001China Shenzhen Key Laboratory for Advanced Materials School of Materials Science and EngineeringHarbin Institute of Technology(Shenzhen)Shenzhen 518055China Center for Composite Materials and Structures Harbin Institute of TechnologyHarbin 150001China

Transition metal carbide/nitride cores within MXenes make them considerably useful for ultra-high-temperature ***,extensive research on Ti_(3)C_(2)T_(x) MXene has revealed its tendency to undergo a phase transition to TiCy at temperatures above 800℃due to high activity of a superficial Ti atomic ***,spark plasma sintering of Ti_(3)C_(2)T_(x) and TiC is performed to prevent the Ti_(3)C_(2)T_(x) phase transition at temperatures up to 1900℃through the fabrication of composites at a pressure of 50 *** a focused ion beam scanning electron microscope to separate layered substances in the composites and examining selected area diffraction spots in a transmission electron microscope enabled identification of non-phase-transitioned ***-principles calculations based on density functional theory indicated the formation of strong chemical bonding interfaces between Ti_(3)C_(2)T_(x) and TiC,which imposed a stability constraint on the Ti atomic layer at the Ti_(3)C_(2)T_(x) *** performance tests,such as three-point bending and fracture toughness analysis,demonstrated that the addition of Ti_(3)C_(2)T_(x) can effectively improve the cross-scale strengthening and toughening of the TiC matrix,providing a new path for designing and developing two-dimensional(2D)carbides cross-scale-enhanced three-dimensional(3D)carbides with the same elements relying on a wide variety of MXenes.

关键词： MXene ultra-high-temperature phase stability interface bonding cross-scale strengthening and toughening structural ceramic composites

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Securing offshore resources development: A mathematical investigation into gas leakage in long-distance flexible pipes

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Petroleum Science 2024年第4期21卷 2734-2744页

作者： Xiang-An lu Liang-Liang jiang Jian-Sheng Zhang Min-Gui Wang Guangling College of Yangzhou University Department of Chemical and Petroleum Engineering University of Calgary Department of Energy and Power Engineering Tsinghua University

Gas flexible pipes are critical multi-layered equipment for offshore oil and gas development. Under high pressure conditions, small molecular components of natural gas dissolve into the polymer inner liner of the flexible pipes and further diffuse into the annular space, incurring annular pressure build-up and/or production of acidic environment, which poses serious challenges to the structure and integrity of the flexible pipes. Gas permeation in pipes is a complex phenomenon governed by various factors such as internal pressure and temperature, annular structure, external temperature. In a long-distance gas flexible pipe, moreover, gas permeation exhibits non-uniform features, and the gas permeated into the annular space flows along the metal gap. To assess the complex gas transport behavior in long-distance gas flexible pipes, a mathematical model is established in this paper considering the multiphase flow phenomena inside the flexible pipes, the diffusion of gas in the inner liner, and the gas seepage in the annular space under varying permeable properties of the annulus. In addition, the effect of a variable temperature is accounted. A numerical calculation method is accordingly constructed to solve the coupling mathematical equations. The annular permeability was shown to significantly influence the distribution of annular pressure. As permeability increases, the annular pressure tends to become more uniform, and the annular pressure at the wellhead rises more rapidly. After annular pressure relief followed by shut-in, the pressure increase follows a convex function. By simulating the pressure recovery pattern after pressure relief and comparing it with test results, we deduce that the annular permeability lies between 123 and 512 m D. The results help shed light upon assessing the annular pressure in long distance gas flexible pipes and thus ensure the security of gas transport in the emerging development of offshore resources.

关键词： Offshore resources development Transport security Long-distance flexible pipes Gas leakage Heat and mass transfer model Finite difference calculation

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Characteristics and main controlling factors of helium resources in the main petroliferous basins of the North China Craton

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Acta Oceanologica Sinica 2024年第2期43卷 23-33页

作者： Zihan Gao Zhi Chen Hongyi He Zhaofei Liu chang lu Hanyu Wang Yili luo Ying Li Institute of Earthquake Forecasting China Earthquake AdministrationBeijing 100036China College of Geosciences China University of Petroleum-BeijingBeijing 102249China School of Earth Science and Resources China University of Geosciences(Beijing)Beijing 100083China

At present, the main controlling factors of helium accumulation is one of the key scientific problems restricting the exploration and development of helium reservoir. In this paper, based on the calculation results of He generation rate and the geochemical characteristics of the produced gas, both the similarities and differences between natural gas and He resources in the Bohai Bay, Ordos and the surrounding Songliao Basin are compared and analyzed, discussing the main controlling factors of helium resources in the three main petroliferous basins of the North China Craton. It is found that the three basins of Bohai Bay, Ordos and Songliao have similar characteristics of source rocks, reservoirs and cap rocks, that's why their methane resource characteristics are essentially the same. The calculated ~4He generation per cubic metamorphic crystalline basement in the three basins is roughly equivalent, which is consistent with the measured He resources, and it is believed that the ~4He of radiogenic from the crust is the main factor controlling the overall He accumulation in the three basins;there is almost no contribution of the mantle-derived CH_4, which suggests that the transport and uplift of mantle-derived ~3He carried by the present-day magmatic activities along the deep-large faults is not the main reason for the mantle-derived ~3He mixing in the basins. Combined with the results of regional volcanic and geophysical studies,it is concluded that under the background of the destruction of North China Craton, magma intrusion carried a large amount of mantle-derived material and formed basic volcanic rocks in the Bohai Bay Basin and Songliao Basin, which replenished mantle-derived ~3He for the interior of the basins, and that strong seismic activities in and around the basins also promoted the upward migration of mantle source ~3He. This study suggests that the tectonic zone with dense volcanic rocks in the Cenozoic era and a high incidence of historical strong ear

关键词： Helium Bohai Bay Basin destruction of the North China Craton fault Cenozoic volcanic rocks strong earthquake activity

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