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Investigation of mechanical failure performance of a large-diameter shield tunnel segmental ring

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第5期25卷 411-428页

作者： Binyong GAO Renpeng CHEN Huaina WU Chengcheng ZHANG meng fan Chao XIAO Research Center of Underground Space Advanced Technology Hunan UniversityChangsha 410082China Key Laboratory of Building Safety and Energy Eficiency of the Ministry of Education Hunan UniversityChangsha 410082China Department of Civil Engineering Hunan UniversityChangsha 410082China China Construction No.5 Civil Engineering Co. Ltd.Changsha 410004China

The control criteria for structural deformation and the evaluation of operational safety performance for large-diameter shield tunnel segments are not yet clearly defined.To address this issue,a refined 3D finite element model was established to analyze the transverse deformation response of a large-diameter segmental ring.By analyzing the stress,deformation,and crack distribution of large-diameter segments under overload conditions,the transverse deformation of the segmental ring could be divided into four stages.The main reasons for the decrease in segmental ring stiffness were found to be the extensive development of cracks and the complete formation of four plastic hinges.The deformation control value for the large-diameter shield tunnel segment is chosen as 8%o of the segment's outer diameter,representing the transverse deformation during the formation of the first semi-plastic hinge(i.e.,the first yield point)in the structure.This control value can serve as a reinforcement standard for preventing the failure of large-diameter shield tunnel segments.The flexural bearing capacity characteristic curve of segments was used to evaluate the structural strength of a large-diameter segmental ring.It was discovered that the maximum internal force combination of the segment did not exceed the segment ultimate bearing capacity curve(SUBC).However,the combination of internal force at 9°,85°,and 161°of the joints,and their symmetrical locations about the 0°-180°axis exceeded the joint ultimate bearing capacity curve(JUBC).The results indicate that the failure of the large-diameter segment lining was mainly due to insufficient joint strength,leading to an instability failure.The findings from this study can be used to develop more effective maintenance strategies for large-diameter shield tunnel segments to ensure their long-term performance.

关键词： Finite element model Transverse deformation response Upper overload Plastic hinges Flexural bearing capacity

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Continuous-flow enzymatic synthesis of chiral lactones in a three-dimensional microfluidic reactor

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Chinese Chemical Letters 2024年第3期35卷 299-303页

作者： Xuelei Deng meng fan Miao Wu Xiaoyan Zhang Ya Cheng Jianye Xia Yingping Zhuang Weiping Zhu Xuhong Qian Yunpeng Bai State Key Laboratory of Bioreactor Engineering Shanghai Collaborative Innovation Center for BiomanufacturingEast China University of Science and TechnologyShanghai 200237China The Extreme Optoelectromechanics Laboratory School of Physics and Materials ScienceEast China Normal UniversityShanghai 200241China Tianjin Institute of Industrial Biotechnology Chinese Academy of SciencesTianjin 300308China

A new continuous-flow process for the enzymatic synthesis of optically pureγ-lactones,which are used as flavors and fragrances in the food and cosmetic industries,was developed in a three-dimensional microfluidic reactor.The microchannels(175 mm in length,0.9 mm in depth,and 1.72 mL in volume)were carved precisely inside a single borosilicate glass(90 mm×75 mm×12 mm)with ultrafast femtosecond laser micromachining.The flow field analysis and reaction simulation showed that the mixing of substrates and enzymes was enhanced,allowing the adjustment of residence time in a wide window.SmCR_(V4),a carbonyl reductase with excellent catalytic activity and enantioselectivity towardγ/δ-keto acids,was employed for the asymmetric synthesis of various chiral lactones.30 mmol/L(R)-γ-decalactone(3g)can be obtained in 26 s with a space-time yield(STY)up to 16,877 g L^(-1)d^(-1),which is 14.4 times higher than the highest STY of batch reaction reported previously.This continuous-flow process was applied to the synthesis of 6 chiral lactones.In addition,the scaled-up synthesis of 3g was carried out in 6 cascade microreactors continuously for 6 h,demonstrating the feasibility and stability of the 3D continuous-flow process in enzymatic synthesis of optically pure compounds.

关键词： Continuous-flow Flow chemistry Microreactor Biocatalysis Carbonyl reductase Asymmetric reduction

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Toward Establishing a Low-cost UAV Coordinated Carbon Observation Network(LUCCN):First Integrated Campaign in China

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Advances in Atmospheric Sciences 2024年第1期41卷 1-7页

作者： Dongxu YANG Tonghui ZHAO Lu YAO Dong GUO meng fan Xiaoyu REN Mingge LI Kai WU Jing WANG Zhaonan CAI Sisi WANG Jiaxu GUO Liangfu CHEN Yi LIU Carbon Neutrality Research Center(CNRC) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Key Laboratory of Middle Atmospheric Physics and Global Environment Observation(LAGEO) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Remote Sensing Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100101China National Remote Sensing Center of China Beijing 100036China The Administrative Center for China’s Agenda 21 Beijing 100862China

In this study,we introduce our newly developed measurement-fed-perception self-adaption Low-cost UAV Coordinated Carbon Observation Network(LUCCN)prototype.The LUCCN primarily consists of two categories of instruments,including ground-based and UAV-based in-situ measurement.We use the GMP343,a low-cost non-dispersive infrared sensor,in both ground-based and UAV-based instruments.The first integrated measurement campaign took place in Shenzhen,China,4 May 2023.During the campaign,we found that LUCCN’s UAV component presented significant data-collecting advantages over its ground-based counterpart owing to the relatively high altitudes of the point emission sources,which was especially obvious at a gas power plant in Shenzhen.The emission flux was calculated by a crosssectional flux(CSF)method,the results of which differed from the Open-Data Inventory for Anthropogenic Carbon dioxide(ODIAC).The CSF result was slightly larger than others because of the low sampling rate of the whole emission cross section.The LUCCN system will be applied in future carbon monitoring campaigns to increase the spatiotemporal coverage of carbon emission information,especially in scenarios involving the detection of smaller-scale,rapidly varying sources and sinks.

关键词： CO_(2) measurement networks power station carbon emission cross-sectional flux method

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Towards advanced zinc anodes by interfacial modification strategies for efficient aqueous zinc metal batteries

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Journal of Energy Chemistry 2024年第6期93卷 79-110,I0003页

作者： Changchun fan Weijia meng Jiaye Ye Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology Ministry of EducationSchool of ChemistryBeihang UniversityBeijing 100191China Shaanxi Key Laboratory of New Transportation Energy and Automotive Energy Saving School of Energy and Electrical EngineeringChang’an UniversityXi’an 710061ShaanxiChina School of Chemistry and Physics Faculty of ScienceQueensland University of TechnologyBrisbaneQLD 4001Australia Centre for Materials Science Queensland University of TechnologyBrisbaneQLD 4001Australia

Developing sustainable and clean energy sources(e.g.,solar,wind,and tide energy)is essential to achieve the goal of carbon neutrality.Due to the discontinuous and inco nsistent nature of common clean energy sources,high-performance energy storage technologies are a critical part of achieving this target.Aqueous zinc metal batteries(AZMBs)with inherent safety,low cost,and competitive performance are regarded as one of the promising candidates for grid-scale energy storage.However,zinc metal anodes(ZMAs)with irreversible problems of dendrite growth,hydrogen evolution reaction,self-corrosio n,and other side reactions have seriously hindered the development and commercialization of AZMBs.An increasing number of researchers are focusing on the stability of ZMAs,so assessing the effectiveness of existing research strategies is critical to the development of AZMBs.This review aims to provide a comprehensive overview of the fundamentals and challenges of AZMBs.Resea rch strategies for interfacial modification of ZMAs are systematically presented.The features of artificial interfacial coating and in-situ interfacial coating of ZMAs are compared and discussed in detail,as well as the effect of modified interfacial ZMA on the full-battery performance.Finally,perspectives are provided on the problems and challenges of ZMAs.This review is expected to offer a constructive reference for the further development and commercialization of AZMBs.

关键词： Aqueous zinc metal batteries Zinc metal anode Interfacial modification Artificial interfacial coating In-situ interfacial coating

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Segment-wise learning control for trajectory tracking of robot manipulators under iteration-dependent periods

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Science China(Information Sciences) 2024年第3期67卷 155-166页

作者： fan ZHANG Deyuan meng Kaiquan CAI The Seventh Research Division Beihang University School of Automation Science and Electrical Engineering Beihang University School of Electronics and Information Engineering Beihang University

This paper is concerned with the amplitude boundedness problem of adaptive iterative learning control(AILC) for robot manipulators operating with iteration-dependent periods. By introducing virtual memory slots for storing historical data, a practical AILC method is proposed to achieve the segmentwise learning. This method requires less memory storage for historical information of previous iterations,especially in comparison with that of the conventional AILC methods using point-wise learning strategies.It is shown that not only the energy boundedness but also the amplitude boundedness of estimates and inputs of practical AILC can be guaranteed. Moreover, the practical AILC method can achieve the perfect tracking objective regardless of iteration-dependent periods when the robot manipulators have a persistent full learning property. In addition, a solution to the visual manipulator platform is provided and deployed based on Coppeliasim and Matlab, which helps to show the amplitude boundedness of learning results and the perfect tracking performances of the proposed practical AILC method for robot manipulators.

关键词： amplitude boundedness iteration-dependent period iterative learning control robot manipulator segment-wise virtual memory slot

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Advances in environmental DNA monitoring:standardization,automation,and emerging technologies in aquatic ecosystems

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Science China(Life Sciences) 2024年第7期67卷 1368-1384页

作者： Suxiang Lu Honghui Zeng fan Xiong meng Yao Shunping He State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of SciencesWuhan 430072China Institute of Ecology College of Urban and Environmental SciencesPeking UniversityBeijing 100871China School of Life Sciences Peking UniversityBeijing 100871China Institute of Deep Sea Science and Engineering Chinese Academy of SciencesSanyaChina Center for Excellence in Animal Evolution and Genetics Chinese Academy of SciencesKunmingChina

Environmental DNA(eDNA)monitoring,a rapidly advancing technique for assessing biodiversity and ecosystem health,offers a noninvasive approach for detecting and quantifying species from various environmental samples.In this review,a comprehensive overview of current eDNA collection and detection technologies is provided,emphasizing the necessity for standardization and automation in aquatic ecological monitoring.Furthermore,the intricacies of water bodies,from streams to the deep sea,and the associated challenges they pose for eDNA capture and analysis are explored.The paper delineates three primary eDNA survey methods,namely,bringing back water,bringing back filters,and bringing back data,each with specific advantages and constraints in terms of labor,transport,and data acquisition.Additionally,innovations in eDNA sampling equipment,including autonomous drones,subsurface samplers,and in-situ filtration devices,and their applications in monitoring diverse taxa are discussed.Moreover,recent advancements in species-specific detection and eDNA metabarcoding are addressed,highlighting the integration of novel techniques such as CRISPR-Cas and nanopore sequencing that enable precise and rapid detection of biodiversity.The implications of environmental RNA and epigenetic modifications are considered for future applications in providing nuanced ecological data.Lastly,the review stresses the critical role of standardization and automation in enhancing data consistency and comparability for robust long-term biomonitoring.We propose that the amalgamation of these technologies represents a paradigm shift in ecological monitoring,aligning with the urgent call for biodiversity conservation and sustainable management of aquatic ecosystems.

关键词： eDNA methodology sampler environment biomonitoring ecogenomic sensors ocean observation instrument

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Recent advances in promising drugs for primary prevention of gastroesophageal variceal bleeding with cirrhotic portal hypertension

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Hepatobiliary & Pancreatic Diseases International 2024年第1期23卷 4-13页

作者： Ji-Yao Sheng Zi-fan meng Qiao Li Yong-Sheng Yang Department of Hepatobiliary and Pancreatic Surgery the Second Hospital of Jilin UniversityChangchun 130041China Jilin Engineering Laboratory for Translational Medicine of Hepatobiliary and Pancreatic Diseases the Second Hospital of Jilin UniversityChangchun 130041China

Background:Gastroesophageal variceal bleeding is one of the most severe complications of patients with cirrhosis.Although primary prevention drugs,including non-selectiveβ-blockers,have effectively reduced the incidence of bleeding,their efficacy is limited due to side effects and related contraindications.With recent advances in precision medicine,precise drug treatment provides better treatment efficacy.Data sources:Literature search was conducted in PubMed,MEDLINE and Web of Science for relevant articles published up to May 2022.Information on clinical trials was obtained from https://clinicaltrials.gov/and http://***/.Results:The in-depth understanding of the pathogenesis and advances of portal hypertension has enabled the discovery of multiple molecular targets for promising drugs.According to the site of action,these drugs could be classified into four classes:intrahepatic,extrahepatic,both intrahepatic and extrahepatic targets and others.All these classes of drugs offer advantages over traditional treatments in prevention of gastroesophageal variceal bleeding in patients with cirrhotic portal hypertension.Conclusions:This review classified and summarized the promising drugs,which prevent gastroesophageal variceal bleeding by targeting specific markers of pathogenesis of portal hypertension,demonstrating the significance of using the precision medicine strategy to discover and develop promising drugs for the primary prevention of gastroesophageal variceal bleeding in patients with cirrhotic portal hypertension.

关键词： Cirrhotic portal hypertension Target drug Primary prevention Bleeding

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Endogenous Candida albicans endophthalmitis in a patient with chronic renal failure on hemodialysis

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International Journal of Ophthalmology(English edition) 2024年第5期17卷 979-981页

作者： meng-Ya Liu Zhi-fan Chen Hao-Sheng Liu Qian-Li meng Department of Ophthalmology Guangdong Provincial People’s Hospital(Guangdong Academy of Medical Sciences)Southern Medical UniversityGuangzhou 510080Guangdong ProvinceChina The Fourth Affiliated Hospital of Guangzhou Medical University Guangzhou 511400Guangdong ProvinceChina

Dear Editor,We report a rare case of endogenous endophthalmitis caused by Candida albicans in a patient with chronic renal failure concomitant hemodialysis.A 71-year-old man with a history of hypertension and 2-year chronic renal failure on hemodialysis via a native arteriovenous fistula(AVF)was presented to the local hospital due to fever 3wk ago.No pathogens were detected through blood culture on admission,and his fever gradually subsided with intravenous ceftriaxone sodium.After a week of fever,he experienced progressive blurred vision in both eyes,accompanied by pain and headaches.Subsequent magnetic resonance imaging(MRI)of the brain revealed sinusitis.He had not undergone any previous eye surgeries or trauma.

关键词： hemodialysis albicans fever

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Zn-air batteries for electric vehicles

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Tungsten 2024年第1期6卷 164-173页

作者： Nai-Qi meng Yu-Xin fan Jing-Sheng Cai State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China College of Energy Soochow Institute for Energy and Materials InnovationS(SIEMIS)Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province Soochow UniversitySuzhou 215006China Institute of New Energy for Vehicles School of Materials Science and EngineeringTongji UniversityShanghai 201804China

The increasingly serious environmental challenges have gradually aroused people's interest in electric vehicles.Over the last decade,governments and automakers have collaborated on the manufacturing of electric vehicles with high performance.Cutting-edge battery technologies are pivotal for the performance of electric vehicles.Zn-air batteries are considered as potential power batteries for electric vehicles due to their high capacity.Zn-air battery researches can be classified into three categories:primary batteries,mechanically rechargeable batteries,and chemically rechargeable batteries.The majority of current studies aim at developing and improving chemically rechargeable and mechanically rechargeable Zn-air batteries.Researchers have tried to use catalytic materials design and device design for Zn-air batteries to make it possible for their applications in electric vehicles.This review will highlight the state-of-the-art in primary batteries,mechanically rechargeable batteries,and chemically rechargeable batteries,revealing the prospects of Zn-air batteries for electric vehicles.

关键词： Energy storage Electric vehicles Bifunctional oxygen catalysts Mechanically rechargeable Zn-air batteries Chemically rechargeable Zn-air batteries

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Applications of single-cell RNA sequencing in spermatogenesis and molecular evolution

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Zoological Research 2024年第3期45卷 575-585页

作者： Wen-Bo Chen meng-Fei Zhang fan Yang Jin-Lian Hua College of Veterinary Medicine Shaanxi Centre of Stem Cells Engineering&TechnologyNorthwest A&F UniversityYanglingShaanxi 712100China Key Laboratory of Livestock Biology Northwest A&F UniversityYanglingShaanxi 712100China

Spermatogenic cell heterogeneity is determined by the complex process of spermatogenesis differentiation.However,effectively revealing the regulatory mechanisms underlying mammalian spermatogenic cell development and differentiation via traditional methods is difficult.Advances in technology have led to the emergence of many single-cell transcriptome sequencing protocols,which have partially addressed these challenges.In this review,we detail the principles of 10x Genomics technology and summarize the methods for downstream analysis of single-cell transcriptome sequencing data.Furthermore,we explore the role of single-cell transcriptome sequencing in revealing the heterogeneity of testicular ecological niche cells,delineating the establishment and disruption of testicular immune homeostasis during human spermatogenesis,investigating abnormal spermatogenesis in humans,and,ultimately,elucidating the molecular evolution of mammalian spermatogenesis.

关键词： Single-cell RNA sequencing(scRNA-seq) Spermatogenesis Molecular evolution Sertoli cell

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