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Chemical Research in Chinese Universities 2006年第1期22卷 36-39页

作者： WU Chun-zan HUANG jia-xing ZhanG Qi-han XU jia-xi Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education College of Chemistry and Molecular Engineering Peking University Beijing 100871 P. R. China

The reactions of 2,3-dihydro-1,5-benzothiazepines with ethoxyearbonylcarbene undergo complex rearrangements to produce rlng-opening and ring contraction products. Previously it was presumed that the different products were formed via different mechanisms depending on the kind of substituents at the 2-position of 1,5-benzothiazepines. However, on the basis of the further detailed investigation, it was found that all 1,5-benzothiazepines can undergo the same rearrangement to yield both ring-opening and ring contraction products.

关键词： 1,5-Benzothiazepine Ethoxycarbonylcarbene Rearrangement Ring-contraction Ring-opening

Performance of a small AT-TPC prototype

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Nuclear Science and Techniques 2018年第7期29卷 138-144页

作者： Jin-Yan Xu Qi-Te Li Yan-Lin Ye jian Gao jia-xing han Shi-Wei Bai Ka-Hou Ng School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking University

A small prototype of an active-target time projection chamber detector based on the gas electron multiplier(GEM) readout technique was designed and *** calculations were performed to analyze the electric field distribution and optimize the *** particular,a guard ring installed above the GEM foil may play an important role in shaping the electric field in the gas vessel and improving the overall performance of the *** best results were obtained at a guard-ring voltage of-950 *** using a collimated a-particle source,an energy resolution of 3.6–4.0 ke V can be achieved for deposited energies of 18–21 keV,respectively.A position resolution of less 0.2 mm was observed along the electron drift direction,whereas the resolution in the readout plane was approximately 0.45 mm.A time resolution of less than 20 ns was *** using helium as the primary working gas as well as the target material,a t a elastic scattering events can be clearly imaged.

关键词：原型性能优化设计模拟计算工作气体宝石时间电子

Electrochemical CO_(2)reduction to C_(2+)products over Cu/Zn intermetallic catalysts synthesized by electrodeposition

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Frontiers in Energy 2024年第1期18卷 80-88页

作者： Ting DENG Shuaiqiang jia Shitao han jianxin ZHAI jiapeng jiaO Xiao CHEN Cheng XUE Xueqing xing Wei XIA Haihong WU Mingyuan HE Buxing han School of Chemistry and Molecular Engineering East China Normal UniversityShanghai 200062China Institute of Eco-Chongming Shanghai 202162China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Institute of Chemistry Chinese Academy of SciencesBeijing 100190China

Electrocatalytic CO_(2)reduction(ECR)offers an attractive approach to realizing carbon neutrality and producing valuable chemicals and fuels using CO_(2)as the ***,the lack of cost-effective electrocatalysts with better performances has seriously hindered its ***,a one-step co-electrodeposition method was used to introduce Zn,a metal with weak^(*)CO binding energy,into Cu to form Cu/Zn intermetallic catalysts(Cu/Zn IMCs).It was shown that,using an H-cell,the high Faradaic efficiency of C_(2+)hydrocarbons/alcohols()could be achieved in ECR by adjusting the surface metal components and the applied *** suitable conditions,FEC_(2+)and current density could be as high as 75%and 40 mA/cm^(2),*** with the Cu catalyst,the Cu/Zn IMCs have a lower interfacial charge transfer resistance and a larger electrochemically active surface area(ECSA),which accelerate the ***,the^(*)CO formed on Zn sites can move to Cu sites due to its weak binding with*CO,and thus enhance the C–C coupling on the Cu surface to form C_(2+)products.

关键词： carbon dioxide electroreduction electrochemistry co-electrodeposition intermetallic catalysts value-added chemicals

Construction of flower-like MoS_(2)decorated on Cu doped CoZn-ZIF derived N-doped carbon as superior microwave absorber

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Nano Research 2024年第9期17卷 8250-8260页

作者： Yun han Di Lan Mengjun han Zihao Xia jiaxiao Zou Zirui jia College of Chemistry and Chemical Engineering Qingdao UniversityQingdao 266071China School of Materials Science and Engineering Hubei University of Automotive TechnologyShiyan 442002China

The rational design of composition nanostructures and morphologies of the carbon-based composites materials has a significant potential for tuning electromagnetic parameters and thereby improving their performance as electromagnetic wave(EMW)*** this work,the flower-like Cu/Co-NC/MoS_(2)(NC=N-doped carbon skeleton)composites were successfully prepared by employing CuCoZn-ZIF(ZIF=zeolitic imidazolate framework)as precursor with subsequent annealing and hydrothermal *** unique flower-like morphology and electromagnetic synergy strategy between components enable the as-obtained Cu/Co-NC/MoS_(2)composites to exhibit outstanding microwave absorption ***,the minimum reflection loss of Cu/Co-NC/MoS_(2)reaches-54.36 dB at 2.7 *** the thickness reduces to 2.2 mm,the maximum effective absorption bandwidth can be achieved as large as 6.72 *** research develops useful ideas for optimizing multicomponent microwave absorbing materials.

关键词： ternary metal-organic frameworks(MOFs) MoS_(2) flower-like morphology microwave absorption

Climatic impacts induced by winter wheat irrigation over North China simulated by the nonhydrostatic RegCM4.7

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Advances in Climate Change Research 2024年第2期15卷 197-210页

作者： jia WU Zhen-Yu han Xue-Jie GAO Zheng-jia LIU National Climate Centre China Meteorological AdministrationBeijing 100081China Key Laboratory for Climate Studies China Meteorological AdministrationBeijing 100081China Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

Quantification of the impact of winter wheat irrigation on the climate and the occurrence of extreme climatic events over North China is crucial for regional adaptation *** related studies mainly focused on the impact on surface processes;however,few focused on the effects of extreme events using high-resolution nonhydrostatic regional climate ***,the 9-km-resolution nonhydrostatic RegCM4.7 was coupled with a crop irrigation scheme and an updated winter wheat irrigation dataset to better simulate irrigation *** experiments were conducted with and without winter wheat irrigation to isolate the effects of *** showed that irrigation simulation reduces the model biases in temperature,precipitation,latent heat flux,soil moisture,sensitive heat flux,and top-layer soil ***,it also reduces the bias and increases the correlation with observations obtained in irrigated areas,especially in summer,indicating better representation of irrigation *** wheat irrigation tends to cause substantial cooling of the local surface maximum,minimum,and mean air temperatures(by-1.68,-0.34,and-0.79℃,respectively)over irrigated areas of North China,with the largest changes observed in relation to maximum ***,precipitation is found to increase during spring and summer,which is strongly related to water vapor transport in the lower levels of the *** analyses indicated that the number of annual mean hot days decrease(-13.9 d),whereas the number of both comfort days(+10.2 d)and rainy days(days with total precipitation greater than 1 mm:+6.6 d)increase over irrigated areas,demonstrating beneficial feedback to human perception and ***,although the heat wave risk increases(number of annual mean heat wave days:+5.8 d),the impact is limited to small areas within irrigated ***,no notable change was found in terms of heavy rainfall events and precipitation intensity

关键词： Nonhydrostatic regional climate model Irrigation effect Extreme events North China

A dynamic exploratory hybrid modelling framework for simulating complex and uncertain system

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Journal of Safety Science and Resilience 2024年第2期5卷 167-178页

作者： Gangqiao Wang han xing Yongqiang Chen Yi Liu Institute of Big Data Inteligent Management and Decision-making College of ManagementShenzhen UniversityShenzhen 518060China School of Safety Science Tsinghua UniversityBejing 100084China Department of Mechanics and Engineering Science College of EngineeringPeking UniversityBejing 100871China

Complex disaster systems involve various components and mechanisms that could interact in complex ways and change over time,leading to significant deep *** to deep uncertainty,decision-makers have severe inadequacy of knowledge and often encounter unpredictable surprises that may emerge in the future,thus making it difficult to specify appropriate models and parameters to describe the system of *** this paper,we propose a dynamic exploratory hybrid modeling framework that fits data,models,and computational ex-periments together to simulate complex systems with deep *** the framework,one needs to develop multiple plausible models from a hybrid modeling perspective and perform enormous computational experi-ments to explore the diversity of future ***-time data is then incorporated into diverse forecasts to dynamically adjust the simulation *** ultimately enables an ongoing modeling and analysis process in which deep uncertainty would be gradually *** approach has been applied to a human-involved car-following system simulation under complex traffic *** results show that the proposed approach can improve the prediction accuracy while enhancing the sensitivity of the simulation system to uncertain changes in the system of interest.

关键词： Disaster modeling and analysis Deepuncertainty Hybrid modeling Adaptivesimulation

Enterococcus faecalis provides protection during scavenging in carrion crow (Corvus corone)

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Zoological Research 2024年第3期45卷 451-463页

作者： Bin Hu jia-Min Wang Qing-Xun Zhang Jing Xu Ya-Nan xing Bo Wang Shu-Yi han Hong-Xuan He CAS Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China College of Life Sciences University of Chinese Academy of SciencesBeijing 100049China Beijing Milu Ecological Research Center Beijing 102600China Beijing Capital International Airport Co. Ltd.Beijing 101300China

The gut microbiota significantly influences host physiology and provides essential ecosystem *** diet can affect the composition of the gut microbiota,the gut microbiota can also help the host adapt to specific dietary *** carrion crow(Corvus corone),an urban facultative scavenger bird,hosts an abundance of pathogens due to its scavenging *** this,carrion crows infrequently exhibit illness,a phenomenon related to their unique physiological *** present,however,the role of the gut microbiota remains incompletely *** this study,we performed a comparative analysis using 16S rRNA amplicon sequencing technology to assess colonic content in carrion crows and 16 other bird species with different diets in Beijing,*** findings revealed that the dominant gut microbiota in carrion crows was primarily composed of Proteobacteria(75.51%)and Firmicutes(22.37%).Significant differences were observed in the relative abundance of Enterococcus faecalis among groups,highlighting its potential as a biomarker of facultative scavenging behavior in carrion ***,*** isolated from carrion crows was transplanted into model mice to explore the protective effects of this bacterial community against Salmonella enterica *** showed that *** down-regulated the expression of pro-inflammatory cytokines tumor necrosis factor alpha(TNF-α),interferon gamma(IFN-γ),and interleukin 6(IL-6),prevented *** colonization,and regulated the composition of gut microbiota in mice,thereby modulating the host’s immune regulatory ***,*** exerts immunoregulatory and anti-pathogenic functions in carrion crows engaged in scavenging behavior,offering a representative case of how the gut microbiota contributes to the protection of hosts with specialized diets.

关键词： Carrion crow Facultative scavenger Gut microbiota Enterococcus faecalis 16S rRNA sequencing

Gravity Change Caused by Heavy Rainfall Detected by A gPhone Gravimeter in Zhengzhou,China

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Journal of Earth Science 2024年第4期35卷 1273-1276页

作者： Lelin xing Yufei han Xiaowei Niu Lei Bai Innovation Academy for Precision Measurement Science and Technology Chinese Academy of SciencesWuhan430077China Wuhan Geodesy National Observation and Research Station Wuhan430077China China Earthquake Networks Center Beijing100045China

The short-term effect of heavy rainfall on gPhone gravimeter observation at Zhengzhou Seismic Station is *** to the observation data during Jul.17–20,2021,the corrected gravity residual reflects the gravimetric response caused by heavy *** observed gravity change is dominated by the local effect considering topographic effect on *** deduced water depth near the observation station is about 300 mm.

关键词： gravity gravity change gravimeter heavy rain Zhengzhou

A PDGFRβ-targeting nanodrill system for pancreatic fibrosis therapy

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Chinese Chemical Letters 2024年第10期35卷 353-359页

作者： han han Bi-Te Chen jia-Rong Ding Jin-Ming Si Tian-jiao Zhou Yi Wang Lei xing Hu-Lin jiang State Key Laboratory of Natural Medicines Department of PharmaceuticsChina Pharmaceutical UniversityNanjing 210009China College of Pharmacy .Yanbian UniversityYanji 133002China Department of Nephrology Changhai HospitalNaval Medical UniversityShanghai 200433China

Activated pancreatic stellate cells(PSCs)are the main source of collagen layer deposition and the key target in pancreatic ***,no effective treatment specific to pancreatic fibrosis clinically,owing to the drug accumulation blocked by the collagen barrier and thus it is difficult to inhibit activated PSCs ***,a PSCs-targeting nano-system based on“nanodrill”strategy(LA-PC)was designed to enhance the accumulation of all-trans retinoic acid(ATRA)in PSCs,relying on the platelet-derived growth factor receptor beta(PDGFRβ)-targeting peptide(p PB:C*SRNLIDC*)and collagenase(Col).After being injected into fibrotic mice via tail vein,the Col modified on LA-PC can remove the excess collagen layer,and the drug delivery efficiency through pPB targeting peptide was more than 5 times higher than that of free ATRA,as well as the degree of fibrosis significantly ***,this nano-system effectively inhibited platelet-derived growth factor subunit B(PDGF-BB)/PDGFRβaxis on PSCs via a down-regulated extracellular signal-regulated protein kinase(ERK)pathway,and accordingly reduced the level of ***,the smart platform provided a promising strategy for the treatment of pancreatic fibrosis to achieve the precise regulation of PSCs.

关键词： Pancreatic fibrosis Pancreatic stellate cells Liposome PDGFRβ pPB peptide

Effects of environment and genotype-by-environment interaction on phenotype of Rorippa elata(Brassicaceae),an endemic alpine plant in the Hengduan mountains

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Journal of Plant Ecology 2024年第4期17卷 42-55页

作者： Zhi-Qiang Du Yao-Wu xing Ting-Shen han CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Plant Diversity and Specialty Crops Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China

Global climate change poses a severe threat to mountain *** plasticity and local adaptation are two common strategies for alpine plant to cope with such *** may facilitate organismal adaptation to contrasting environments,depending on the influences of the environment or genotype or their interacted *** this study,we use an endemic alpine plant(Rorippa elata)in the Hengduan mountains(HDM)to unravel its phenotypic basis of adaptation strategy and evaluate the relative contributions of environment and genotype to its *** transplanted 37 genotypes of *** into two common gardens across low and high elevations(2800 vs.3800 m)during *** fitness-related traits were measured,including flowering probability and glucosinolates(GS)*** estimated the environmental or genotypic contributions to the phenotype and identified the main environmental *** results revealed that both environment and genotype-by-environment interactions contributed to the phenotypes of *** heterogeneity was identified as a key factor that explained 24%of the total phenotypic *** particular,genotypes of the northern HDM showed significantly higher plasticity in flowering probability than those of the southern ***,within the southern HDM,GS content indicated local adaptation to herbivory stresses for *** genotypes along *** conclusion,our results suggest that *** may have adapted to the alpine environment through species-level plasticity or regional-level local *** processes were shaped by either complex topography or interactions between genotype and mountain *** study provides empirical evidence on the adaptation of alpine plants.

关键词： alpine plant common garden genotype-by-environment Hengduan mountains local adaptation phenotypic plasticity