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Recent advances in transition-metal catalyzed nitrene transfer reactions with carbamates

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Chinese Chemical Letters 2024年第3期35卷 76-86页

作者： Yanshu Luo xinyu zhang Yuanzhi Xia College of Chemistry and Materials Engineering Wenzhou UniversityWenzhou 325035China

Nitrene transfer reactions are powerful tools in synthetic organic *** recent years,transitionmetal catalyzed nitrene transfer reactions with carbamates as the nitrene precursors have been widely *** species undergoes facile C-H amination,aziridination,and bifunctionalization of alkenes under the catalysis of different transition metals including Rh,Fe,Ru and others,enabling the efficient construction of various nitrogen-containing *** this review,the recent developments in nitrene transfer reactions with carbamates via N-O bond cleavage were introduced based on different types of reaction,and the key mechanistic information and synthetic applications of the methodologies were discussed.

关键词： Transition-metal catalysis Nitrene transfer Carbamate C—H amination Aziridination Bifunctionalization

Kriging Model Averaging Based on Leave-One-Out Cross-Validation Method

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Journal of Systems Science & Complexity 2024年第5期37卷 2132-2156页

作者： FENG Ziheng ZONG Xianpeng XIE Tianfa zhang xinyu School of Mathematics Statistics and MechanicsBeijing University of TechnologyBeijing 100124China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China

In recent years,Kriging model has gained wide popularity in various fields such as space geology,econometrics,and computer *** a result,research on this model has *** this paper,the authors propose a model averaging estimation based on the best linear unbiased prediction of Kriging model and the leave-one-out cross-validation method,with consideration for the model *** authors present a weight selection criterion for the model averaging estimation and provide two theoretical justifications for the proposed ***,the estimated weight based on the proposed criterion is asymptotically optimal in achieving the lowest possible prediction ***,the proposed method asymptotically assigns all weights to the correctly specified models when the candidate model set includes these *** effectiveness of the proposed method is verified through numerical analyses.

关键词： Asymptotic optimality best linear unbiased prediction cross-validation Kriging model model averaging

Defusing Triple Pressure to Promote High-Quality Economic Development Rapidly

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2024年第1期19卷 30-58页

作者： WANG Hongju zhang xinyu Schoolof Applied Economics University of Chinese Academyof Social SciencesBeijing 12488China National Academy of Economic Strategy Chinese Academy of Social SciencesBeijing 100006China School of Finance Zhejiang University of Finance&EconomicsHangzhou 310018China

Since the 18th National Congress of the Communist Party of China(CPC),the quality of China's economic development has been continuously ***,the year 2022 witnessed a subdued economic growth *** triple pressures continue to evolve,with contraction in demand as the primary contradiction facing China's macro economy in the short *** contrast to major economies in the world,China grapples with a low economic growth-inflation index combination,a pace of economic expansion trailing behind its potential,and a mounting unemployment *** impact of supply on price increases weakens,while the global industrial and supply chains are amidst continuous *** the consumer confidence index(Ccl)and the purchasing managers'index(PMl)remain *** expectation for the depreciation of the RMB against US dollar is *** 2023,China will continue to improve the financing environment and carry out a proactive fiscal ***,there is a moderation trend in the trajectory of the interest rate of the Federal Reserve System *** together,these factors(triple pressures)are expected to mitigate the contraction in demand,thereby steering the economy toward robust ***,it is crucial to recognize that low economic growth in the long term may compromise the quality of economic *** year 2023 is the first year of accelerating Chinese modernization after the 2Oth National Congress of the *** should integrate the strategy to expand internal demand with its efforts to deepen supply-side structural *** can foster the coordinated growth of both economic quality and speed,making a good start for Chinese modernization.

关键词： high-quality development output gap strategy to expand domestic demand supply-sidestructuralreform

Investigation of Projectile Impact Behaviors of Graphene Aerogel Using Molecular Dynamics Simulations

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3047-3061页

作者： xinyu zhang Wenjie Xia Yang Wang Liang Wang Xiaofeng Liu Department of Engineering Mechanics Shanghai Jiao Tong UniversityShanghai200240China Department of Aerospace Engineering Iowa State UniversityAmesIA50011USA School of Materials Science and Engineering University of Science&Technology BeijingBeijing100083China Zernike Institute for Advanced Materials University of GroningenGroningen9747The Netherlands

Graphene aerogel(GA),as a novel solid material,has shown great potential in engineering applications due to its unique mechanical *** this study,the mechanical performance of GA under high-velocity projectile impacts is thoroughly investigated using full-atomic molecular dynamics(MD)*** study results show that the porous structure and density are key factors determining the mechanical response of GA under impact ***,the impact-induced penetration of the projectile leads to the collapse of the pore structure,causing stretching and subsequent rupture of covalent bonds in graphene ***,the effects of temperature on the mechanical performance of GA have been proven to be minimal,thereby highlighting the mechanical stability of GA over a wide range of ***,the energy absorption density(EAD)and energy absorption efficiency(EAE)metrics are adopted to assess the energy absorption capacity of GA during projectile *** research findings of this work demonstrate the significant potential of GA for energy absorption applications.

关键词： Graphene aerogel molecular dynamics simulation impact response energy absorption

Facilitating prelithiation of silicon carbon anode by localized high-concentration electrolyte for high-rate and long-cycle lithium storage

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Carbon Energy 2024年第6期6卷 216-233页

作者： Yuanxing zhang Borong Wu Jiaying Bi xinyu zhang Daobin Mu Xin-Yu zhang Ling zhang Yao Xiao Feng Wu School of Materials Science and Engineering Beijing Institute of TechnologyBeijingChina Chongqing Innovation Center Beijing Institute of TechnologyChongqingChina College of New Energy Xi′an Shiyou UniversityXi′anChina Institute for Carbon Neutralization College of Chemistry and Materials EngineeringWenzhou UniversityWenzhouChina Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjinChina

The commercialization of silicon-based anodes is affected by their low initial Coulombic efficiency(ICE)and capacity decay,which are attributed to the formation of an unstable solid electrolyte interface(SEI)***,a feasible and cost-effective prelithiation method under a localized highconcentration electrolyte system(LHCE)for the silicon-silica/graphite(Si-SiO_(2)/C@G)anode is designed for stabilizing the SEI layer and enhancing the *** thin SiO_(2)/C layers with-NH_(2) groups covered on nano-Si surfaces are demonstrated to be beneficial to the prelithiation process by density functional theory calculations and electrochemical *** SEI formed under LHCE is proven to be rich in ionic conductivity,inorganic substances,and flexible organic ***,faster Li+transportation across the SEI further enhances the prelithiation effect and the rate performance of Si-SiO_(2)/C@G *** also leads to uniform decomposition and high stability of the SEI with abundant organic *** a result,the prepared anode shows a high reversible specific capacity of 937.5 mAh g^(-1)after 400 cycles at a current density of 1 *** 811‖Li-SSGLHCE full cell achieves a high-capacity retention of 126.15 mAh g^(-1)at 1 C over 750 cycles with 84.82%ICE,indicating the great value of this strategy for Si-based anodes in large-scale applications.

关键词： localized high-concentration electrolytes prelithiation SEI layer silicon anode

Ab Initio Design of Ni-Rich Cathode Material with Assistance of Machine Learning for High Energy Lithium-Ion Batteries

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Energy & Environmental Materials 2024年第6期7卷 74-83页

作者： xinyu zhang Daobin Mu Shijie Lu Yuanxing zhang Yuxiang zhang Zhuolin Yang Zhikun Zhao Borong Wu Feng Wu School of Materials Science and Engineering Beijing Institute of TechnologyBeijing100081 China

With the widespread use of lithium-ion batteries in electric vehicles,energy storage,and mobile terminals,there is an urgent need to develop cathode materials with specific ***,existing material control synthesis routes based on repetitive experiments are often costly and inefficient,which is unsuitable for the broader application of novel *** development of machine learning and its combination with materials design offers a potential pathway for optimizing ***,we present a design synthesis paradigm for developing high energy Ni-rich cathodes with thermal/kinetic simulation and propose a coupled image-morphology machine learning *** paradigm can accurately predict the reaction conditions required for synthesizing cathode precursors with specific morphologies,helping to shorten the experimental duration and *** the model-guided design synthesis,cathode materials with different morphological characteristics can be obtained,and the best shows a high discharge capacity of 206 mAh g^(−1)at 0.1C and 83%capacity retention after 200 *** work provides guidance for designing cathode materials for lithium-ion batteries,which may point the way to a fast and cost-effective direction for controlling the morphology of all types of particles.

关键词： design digital image lithium-ion batteries machine learning NCM cathode

Determining an optimal control strategy for anthropogenic VOC emissions in China based on source emissions and reactivity

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Journal of Environmental Sciences 2024年第2期136卷 248-260页

作者： Ruipeng Wang Xiaoqi Wang Shuiyuan Cheng Jiaxian Zhu xinyu zhang Long Cheng Kai Wang Key Laboratory of Beijing on Regional Air Pollution Control Faculty of Environment and LifeBeijing University of TechnologyBeijing 100124China

An evidence-based control strategy for emission reduction of VOC sources can effectively solve the regional PM2.5and O3compound pollution in *** estimated the anthropogenic VOC emission inventory in China in 2018 and established a source profile database containing 129 sources based on localized detection and the latest research ***,the distribution of the ozone formation potential(OFP)and secondary organic aerosol formation potential(SOAFP)for emission sources was ***,priority control routes for VOC emission sources were proposed for different *** VOC emissions in China reached 27,211.8 Gg in 2018,and small passenger cars,industrial protective coatings,biomass burning,heavy trucks,printing,asphalt paving,oil storage and transportation,coking,and oil refining were the main *** protective coatings,small passenger cars,and biomass burning all contributed significantly to OFP and *** in emission reduction control should be given to industrial protective coatings,small passenger cars,heavy trucks,coking,printing,asphalt paving,chemical fibers,and basic organic chemical sources over the medium and long term in *** addition,the priority control route for VOC emission sources should be adjusted according to the variations in VOC emission characteristics and regional differences,so as to obtain the maximum environmental benefits.

关键词： Volatile organic compounds Anthropogenic emission inventory Reactivity Emission projection Priority control route

Data-driven prediction of dimensionless quantities for semi-infinite target penetration by integrating machine-learning and feature selection methods

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Defence Technology（防务技术） 2024年第10期40卷 105-124页

作者： Qingqing Chen xinyu zhang Zhiyong Wang Jie zhang Zhihua Wang Institute of Applied Mechanics College of Mechanical and Vehicle EngineeringTaiyuan University of TechnologyTaiyuan 030024China Shanxi Key Lab.of Material Strength&structural Impact College of Mechanical and Vehicle EngineeringTaiyuan 030024China Department of Civil and Environmental Engineering National University of Singapore1 Engineering Drive 2117576Singapore

This study employs a data-driven methodology that embeds the principle of dimensional invariance into an artificial neural network to automatically identify dominant dimensionless quantities in the penetration of rod projectiles into semi-infinite metal targets from experimental *** derived mathematical expressions of dimensionless quantities are simplified by the examination of the exponent matrix and coupling relationships between feature *** a physics-based dimension reduction methodology,this way reduces high-dimensional parameter spaces to descriptions involving only a few physically interpretable dimensionless quantities in penetrating *** the relative importance of various dimensionless feature variables on the penetration efficiencies for four impacting conditions is evaluated through feature selection *** results indicate that the selected critical dimensionless feature variables by this synergistic method,without referring to the complex theoretical equations and aiding in the detailed knowledge of penetration mechanics,are in accordance with those reported in the ***,the determined dimensionless quantities can be efficiently applied to conduct semi-empirical analysis for the specific penetrating case,and the reliability of regression functions is validated.

关键词： Data-driven dimensional analysis Penetration Semi-infinite metal target Dimensionless numbers Feature selection

Visibility restoration for real-world hazy images via improved physical model and Gaussian total variation

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Frontiers of Computer Science 2024年第1期18卷 267-269页

作者： Chuan LI Enping HU xinyu zhang Hao ZHOU Hailing XIONG Yun LIU College of Computer and Information Science Southwest UniversityChongqing 400715China School of Big Data and Intelligent Engineering Chongqing College of International Business and EconomicsChongqing 401520China College of Artificial Intelligence Southwest UniversityChongqing 400715China College of Electronic and Information Engineering Southwest UniversityChongqing 400715China

1 Introduction Under real-world haze conditions,the existence of haze particles in the atmosphere reduces the visibility of captured ***,the noise is inevitably introduced into the degraded image,which further deteriorates the visual quality of the *** enhance the visibility and quality of outdoor real-world hazy images,numerous algorithms have been proposed to remove haze from a single input *** existing methods are broadly lumped into two categories:prior-based methods[1,2]and learning-based methods[3–6].Unfortunately,the widely used atmospheric scattering model and the corresponding haze removal methods fail to take the noise interference into account,which may result in poor visibility restoration performance.

关键词： visibility remove noise