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Photocatalytic vinyl radical-mediated multicomponent 1,4-/1,8-carboimination across alkynes and olefins/(hetero)arenes

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Science China Chemistry 2024年第2期67卷 558-567页

作者： shan-shan Li Yu-Shi jiang Xue-Ling Luo Xuming Ran Yuqiang Li Dong Wu Cheng-Xue Pan Peng-Ju Xia School of Chemistry and Pharmaceutical Sciences Guangxi Normal UniversityGuilin541004China shanghai Artificial Intelligence Laboratory Shanghai200433China The Institute for Advanced Studies Wuhan UniversityWuhan430064China

We developed a highly selective and efficient multicomponent transformation by utilizing alkynes and olefins/(hetero)arenes through photoinduced energy-transfer *** reaction involves the formation of three distinct chemical bonds,namely C(sp~3)–C(sp~2),C(sp~2)–C(sp~3),and C(sp~3)–N,in a single coordinated *** strategy used a vinyl radical-mediated radical relay approach under mild conditions,exhibiting a broad substrate scope(>70 examples),excellent functional-group tolerance,and remarkable regio-and *** the utilization of a combination of experimental techniques and density functional theory(DFT),we delved deeper into the mechanistic intricacies of this distinctive *** revealed that the selective radical addition to electron-deficient alkynes,rather than olefins,was governed by the inherent reactivity of alkyl *** discovery presented a highly effective approach for the synthesis of stereodefined multisubstituted alkenes.

关键词： alkyne-olefin coupling DFT studies regio-and anti-stereoselectivity multisubstituted alkenes

Shock-induced chemical reaction characteristics of PTFE-Al-Bi_(2)O_(3)reactive materials

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Defence Technology（防务技术） 2024年第6期36卷 1-12页

作者： Chunlan jiang Rong hu Jingbo Zhang Zaicheng Wang Liang Mao State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

A ternary system of PTFE/Al/Bi_(2)O_(3)is constructed by incorporating PTFE-based reactive material and thermite for enhancing the energy release of the PTFE-based reactive *** effects of Bi_(2)O_(3)in the PTFE/Al/Bi_(2)O_(3)on both mechanical properties and the energy release were investigated through various tests such as thermogravimetry-differential scanning calorimetry,adiabatic oxygen bomb test and split Hopkinson pressure bar *** microstructure observed through scanning electron microscope and Xray diffraction results are used to analyze the ignition and reaction mechanism of PTFE/Al/Bi_(2)O_(3).The results indicate that the PTFE/Al/Bi_(2)O_(3)are capable of triggering the exothermic reaction of molten PTFE/Bi_(2)O_(3)and Al/Bi_(2)O_(3)over the PTFE/Al reactive materials,thereby promoting *** excessive aluminum in the ternary system is beneficial for increasing energy *** ignition of shock-induced chemical reactions in PTFE/Al/Bi_(2)O_(3)is closely related to the material *** dominant mechanism for hot-spot generation under Split Hopkinson Pressure Bar test is the frictional temperature rise at the microcrack after failure.

关键词： PTFE/Al/Bi_(2)O_(3) Shock-induced chemical reaction Energy release

Modular Soft Robotic Crawlers Based on Fluidic Prestressed Composite Actuators

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Journal of Bionic Engineering 2024年第2期21卷 694-706页

作者： Zefeng Xu Linkai hu Longya Xiao Hongjie jiang Yitong Zhou Shien-Ming Wu School of Intelligent Engineering South China University of TechnologyGuangzhou511442China School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou510006China

Soft robotic crawlers have limited payload capacity and crawling *** study proposes a high-performance inchworm-like modular robotic crawler based on fluidic prestressed composite(FPC)*** FPC actuator is precurved and a pneumatic source is used to flatten it,requiring no energy cost to maintain the equilibrium curved *** and depressurizing the actuators generate alternating stretching and bending motions of the actuators,achieving the crawling motion of the robotic ***-modal locomotion(crawling,turning,and pipe climbing)is achieved by modular reconfiguration and gait *** analytical kinematic model is proposed to characterize the quasi-static curvature and step size of a single-module *** configurations of robotic crawlers are fabricated to demonstrate the crawling ability of the proposed design.A set of systematic experiments are set up and conducted to understand how crawler responses vary as a function of FPC prestrains,input pressures,and actuation *** per the experiments,the maximum carrying load ratio(carrying load divided by robot weight)is found to be 22.32,and the highest crawling velocity is 3.02 body length(BL)per second(392 mm/s).Multi-modal capabilities are demonstrated by reconfiguring three soft crawlers,including a matrix crawler robot crawling in amphibious environments,and an inching crawler turning at an angular velocity of 2/s,as well as earthworm-like crawling robots climbing a 20 inclination slope and pipe.

关键词： Soft robot Soft crawler Fluidic prestressed composite Kinematic model Enhanced loading Multi-modal capability

Application of transgenic mice to the molecular pathogenesis of cataract

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International Journal of Ophthalmology(English edition) 2024年第10期17卷 1929-1948页

作者： Yue Zhang Xiao-Ya Chen Yu-Zhu hu Xiao Zhang Shun-Fei Zheng shan-shan hu Mudanjiang Medical University Mudanjiang 157011Heilongjiang ProvinceChina Department of Ophthalmology Hongqi Hospital of Mudanjiang Medical UniversityMudanjiang 157011Heilongjiang ProvinceChina

One of the most prevalent disorders that cause blindness worldwide is cataract,and its essence is the visual disorder caused by the opacity of the *** significant degree of variation in cataracts and the fact that a variety of factors can impact a patient’s lens transparency make it especially crucial to investigate the pathogenesis of cataracts at the molecular *** has been found that more than 60 genes are linked to the formation of cataracts,and the construction of a transgenic mouse model of cataract similar to the selection of human lens clouding due to a variety of causes has become an important means of studying the pathogenesis of ***,the research on the application of transgenic mice to the molecular pathogenesis of cataracts will be the main topic of this review of the literature.

关键词： transgenic mice cataract lens

Natural convection in nanofluid enclosure under magnetic field:Entropy generation and economic analysis

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Propulsion and Power Research 2024年第2期13卷 273-293页

作者： jiang-Tao hu Shuo-Jun Mei School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 519082China School of Civil Engineering Central South University of Forestry and TechnologyChangsha 410004China hunan Province Key Laboratory of Engineering Rheology Central South University of Forestry and TechnologyChangsha 410004China Key Laboratory of Tropical Atmosphere-Ocean System(Sun Yat-sen University) Ministry of EducationZhuhai 519000China

This study investigates the unsteady natural convection and entropy generation under the effects of magnetic field and baffles inside a nanofluid filled E-shaped *** nanofluid flow is driven by time-varying sidewall temperature and is partitioned by *** factors are discussed,including the enclosure aspect ratio(0.2≤AR≤0.7),nanofluid volume fractions(0≤φ≤0.1),Hartmann numbers(0≤Ha≤80),frequency of time-varying side wall temperature(0.01≤ω≤0.1),baffle locations(0≤d≤0.4)and length(0≤l≤0.4).An economic analysis is conducted to show the nanofluid cost of enhancing thermal transfer and reducing entropy *** modelling results show that increasing aspect ratio and nanofluid volume fraction enhance the thermal transfer behavior,while the magnetic field suppresses the nanofluid natural *** entropy generation monotonically decreases with the increasing nanofluid volume fraction and Hartmann *** baffles into horizontal walls can boost the thermal transfer behavior and decrease the total entropy generation.

关键词： Conjugated heat transfer Economic analysis Entropy generation Time-varying sidewall temperature Magneticﬁeld

Hourly land surface temperature retrieval over the Tibetan Plateau using Geo-LightGBM framework: Fusion of Himawari-8 satellite, ERA5 and site observations

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Advances in Climate Change Research 2024年第4期15卷 623-635页

作者： Zhao-hua LIU shan-shan WENG Zhao-Liang ZENG Ming-hu DING Ya-Qiang WANG Zhehao LIANG Civil and Surveying&Mapping Engineering Jiangxi University of Science and TechnologyGanzhou 341000China State Key Laboratory of Severe Weather Chinese Academy of Meteoroogical Sciences Beijing 100081China Space Geodesy and Geoinformation Technical Unviersity of BerlinBerlin 10623Germany

The Tibetan Plateau(TP)is highly sensitive to even minor fluctuations in land surface temperature(LST),which can result in permafrost melting and degradation of alpine grasslands,leading to serious ecological ***,it is crucial to have high-temporal-resolution and seamless hourly estimating and monitoring of LST for a better understanding of climate change on the ***,we employed Himawari-8 satellite,Digital Elevation Model(DEM),ERA5 reanalysis and meteorological station observations data to develop a new LightGBM framework(called Geo-LightGBM)for estimating LST on the TP,and then analyzed the spatiotemporal variations of those ***-LightGBM demonstrated excellent LST estimation accuracy,with an R2(coefficient of determination)of 0.971,RMSE(root-mean-square error)of 2.479℃,and MAE(mean absolute error)of 1.510℃.The estimated LST values for the year 2020 agreed well with observed values,with remarkable differences in hourly LST ***,the estimated LST was more accurate than that from ***,there were two high LST centers,located in the Yarlung Zangbo River Basin and the Qaidam Basin,and a low LST center located in the central *** SHAP(SHapley Additive exPlanations)and correlation analyses revealed DSCS(the mean ground downward shortwave radiation under clear-sky conditions)to be the most importantly input variable for estimating *** dummy variables(e.g.,longitude,latitude,DEM)were also found to be crucial for model accuracy *** findings indicate the potential for constructing a high-precision and seamless 24-h LST real-time retrieval and monitoring platform for the TP by combining satellite and China's independently developed CLDAS(China Land Data Assimilation System)data in future.

关键词： Tibetan Plateau Himawari-8 ERA5 Land surface temperature Geo-LightGBM

Flux phases in the extended hubbard model on the triangular lattice

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Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 148-153页

作者： Yuge Chen Kun jiang Yi Zhang jiangping hu Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China Department of Physics and Institute for Quantum Science and Technology Shanghai UniversityShanghai 200444China shanghai Key Laboratory of High Temperature Superconductors and International Center of Quantum and Molecular Structures Shanghai UniversityShanghai 200444China Kavli Institute of Theoretical Sciences University of Chinese Academy of SciencesBeijing 100190China New Cornerstone Science Laboratory Beijing 100190China

Using the unrestricted Hartree-Fock variational method,we study the extended hubbard model in the triangular lattice at 3/4 *** to the nesting instability of the Fermi surface,various density wave states compatible with the 2×2 supercell are found as the ground state by tuning the onsite and nearest neighbor repulsions U and ***,the flux phases with complex bond order parameters are realized in a wide range of the U-V phase *** also acquire nontrivial topological properties due to the spontaneous breaking of the time-reversal *** study suggests that the flux phases can be stabilized by the interplay between short-range repulsive interactions in correlated electron systems.

关键词： flux state triangular lattice hubbard model

Research on the mechanism of rockburst induced by mined coal-rock linkage of sharply inclined coal seams

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 929-942页

作者： Xingping Lai huicong Xu Pengfei shan Qinxin hu Weixi Ding shangtong Yang Zhongming Yan College of Energy Science and Engineering Xi’an University of Science and TechnologyXi’an 710054China State Key Laboratory of Green Low Carbon Development of Oil-rich Coal in Western China Xi’an 710054China College of Future Technology Xi’an University of Science and TechnologyXi’an 710054China Department of Civil and Environmental Engineering University of StrathclydeGlasgowG11XJUK

In recent years,the mining depth of steeply inclined coal seams in the Urumqi mining area has gradually *** deformation of mining coal-rock results in frequent *** has become a critical issue that affects the safe mining of deep,steeply inclined coal *** this work,we adopt a perspective centered on localized deformation in coal-rock mining and systematically combine theoretical analyses and extensive data mining of voluminous microseismic *** describe a mechanical model for the urgently inclined mining of both the sandwiched rock pillar and the roof,explaining the mechanical response behavior of key disaster-prone zones within the deep working face,affected by the dynamics of deep *** exploring the spatial correlation inherent in extensive microseismic data,we delineate the“time-space”response relationship that governs the dynamic failure of coal-rock during the progression of the sharply inclined working *** results disclose that(1)the distinctive coal-rock occurrence structure characterized by a“sandwiched rock pillar-B6 roof”constitutes the origin of rockburst in the southern mining area of the Wudong Coal Mine,with both elements presenting different degrees of deformation localization with increasing mining depth.(2)As mining depth increases,the bending deformation and energy accumulation within the rock pillar and roof show nonlinear *** localized deformation of deep,steeply inclined coal-rock engenders the spatial superposition of squeezing and prying effects in both the strike and dip directions,increasing the energy distribution disparity and stress asymmetry of the“sandwiched rock pillar-B3+6 coal seam-B6 roof”*** makes worse the propensity for frequent dynamic disasters in the working face.(3)The developed high-energy distortion zone“inner-outer”control technology effectively reduces high stress concentration and energy distortion in the surrounding *** implementation,the averag

关键词： steeply inclined coal seam localized deformation mechanism of induced rockburst prevention and control of rockburst

HTDcr:a job execution framework for high-throughput computing on supercomputers

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Science China(Information Sciences) 2024年第1期67卷 69-85页

作者： Jiazhi jiang Dan huANG hu CHEN Yutong LU Xiangke LIAO School of Computer Science and Engineering Sun Yat-sen University School of Software Engineering South China University of Technology

High-throughput computing(HTC) is a computing paradigm that aims to accomplish jobs by easily breaking them into smaller,independent ***,it requires a large amount of computing power for a long *** existing HTC frameworks are job-oriented without support for coscheduling with hardware architecture and task-level ***,most of the frameworks reach a limited scale,and their usability needs further ***,we present HTDcr,a job execution framework for the HTC on *** study aims to improve the throughput,task dispatching,and usability of the *** detail,the throughput optimizations include a sophisticated designed task management system,a hierarchical scheduler,and the co-optimization of the task-scheduling strategy with the application and hardware *** optimizations for usability include a programable execution workflow,mechanisms for more robust and reliable service qualities,and a fine-grained resource allocation system for the colocation of multiple *** to our evaluations,HTDcr can achieve outstanding scalability and high throughput on large-scale clusters for the HTC *** evaluate HTDcr with several microbenchmarks and real-world applications on Tianhe-2 and Sunway TaihuLight to demonstrate its effects on existing design *** instance,the task scheduling for two real-world applications integrated with the application and hardware characteristics achieves 1.7× and 1.9× speedups over the basic task-scheduling strategy.

关键词： high-throughput computing supercomputer task scheduling middleware password guessing