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A Reliable Iteration Algorithm for One-Bit Compressive Sensing on the Unit Sphere

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 801-822页

作者： Yan-cheng LU ning BI An-hua WAN School of Mathematics Sun Yat-sen UniversityGuangzhou 510275China

The one-bit compressed sensing problem is of fundamental importance in many areas,such as wireless communication,statistics,and so ***,the optimization of one-bit problem coustrained on the unit sphere lacks an algorithm with rigorous mathematical proof of convergence and *** this paper,an iteration algorithm is established based on difference-of-convex algorithm for the one-bit compressed sensing problem constrained on the unit sphere,with iterating formula■,where C is the convex cone generated by the one-bit measurements andη_(1)>η_(2)>1/*** new algorithm is proved to converge as long as the initial point is on the unit sphere and accords with the measurements,and the convergence to the global minimum point of the l_(1)norm is discussed.

关键词： one-bit compressed sensing difference of convex algorithm iteration algorithm ■1-minimization

Organic Synthesis through Radical Innovation:Frustrated Radical Pairs

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Chinese Journal of Chemistry 2024年第10期42卷 1157-1160页

作者： Zhibin Hu Zengrui cheng ning Jiao State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityBeijing 100191China Shanghai Key Laboratory of Green Chemistry and Chemical Processes East China Normal UniversityShanghai 200062China

Frustrated Lewis Pairs(FLPs)represent a unique class of interactions in Lewis acid-base chemistry,driven by spatial hindrance or incongruent orbital energy levels that hinder the formation of effective coordination *** have received significant attention for their application in activating small molecules and facilitating organic synthesis *** developments have led to the emergence of Frustrated Radical Pairs(FRPs)as an extension of the radical *** are formed from FLPs through Single Electron Transfer(SET)and exhibit the ability to activate a variety of chemical *** research on FLPs is well-established,investigations into FRPs in organic reactions remain *** review highlights the current state of FRPs in organic synthesis,delves into mechanistic insights,explores their potential,and underscores the challenges in this emerging field.

关键词： Radicals Frustrated Lewis Pairs Frustrated Radical Pairs Methodology and reactions Reaction mechanisms

Sustainable production of high-energy-density jet fuel via cycloaddition reactions

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Journal of Energy Chemistry 2024年第8期95卷 712-722,I0016页

作者： Yan-cheng Hu Yingying Zhao ning Li Jing-Pei Cao School of Chemical Engineering and Technology China University of Mining and TechnologyXuzhou 221116JiangsuChina School of Education Science Jiangsu Normal UniversityXuzhou 221116JiangsuChina CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina

Developing an energy supply-chain based on renewable biomass holds great potential to build a low carbon ***-energy-density(HED)jet fuel,featuring unique fused/strained cycloalkanes,is of great significance for volume-limited military aircrafts,as their high density and combustion heat can extend flight duration and increase the ***,the exploration of biomass-based routes towards HED fuel has drawn much attention over the past *** reaction features rapid construction of various carbocycles in an atom-and step-economical *** elegant strategy has been widely applied in the manufacture of sustainable HED *** we carefully summarize the progress achieved in this fascinating area and the review is categorized by the cycloaddition patterns including[4+2],[2+2],[4+4],and[2+1]***,the energy densities of the as-prepared biofuels and petroleumbased fuels(conventional Jet-A and advanced JP-10)are also *** review will provide important insights into rational design of new HED fuel with different ring-types/sizes and inspire the chemists to turn those literature studies into practical applications in military field.

关键词： High-energy-density fuel Biomass-based chemicals Cycloaddition Cycloalkanes Catalysis

Exploration of microscopic physical processes of Z-pinch by a modified electrostatic direct implicit particle-in-cell algorithm

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Chinese Physics B 2024年第9期33卷 433-442页

作者： Kaixuan Li cheng ning Ye Dong Chuang Xue Institute of Applied Physics and Computational Mathematics Beijing 100088China

For investigating efficiently the stagnation kinetic-process of Z-pinch,we develop a novel modified electrostatic implicit particle-in-cell algorithm in radial one-dimension for Z-pinch simulation in which a small-angle cumulative binary collision algorithm is *** our algorithm,the electric field in z-direction is solved by a parallel electrode-plate model,the azimuthal magnetic field is obtained by Ampere’s law,and the term for charged particle gyromotion is approximated by the cross product of the averaged velocity and magnetic *** simulation results of 2 MA deuterium plasma shell Zpinch,the mass-center implosion trajectory agrees generally with that obtained by one-dimensional MHD simulation,and the plasma current also closely aligns with the external *** phase space diagrams and radial-velocity probability distributions of ions and electrons are *** main kinetic characteristic of electron motion is thermal equilibrium and oscillation,which should be oscillated around the ions,while that of ion motion is implosion *** the region of stagnation radius,the radial-velocity probability distribution of ions transits from the non-equilibrium to equilibrium state with the current increasing,while of electrons is basically the equilibrium *** the initial ion density and current peak are not high enough,the ions may not reach their thermal equilibrium state through collisions even in its stagnation phase.

关键词： Z-pinch particle-in-cell ion heating charged particle collisions

Unveiling evapotranspiration patterns and energy balance in a subalpine forest of the Qinghai-Tibet Plateau:observations and analysis from an eddy covariance system

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Journal of Forestry Research 2024年第3期35卷 175-188页

作者： Niu Zhu Jinniu Wang Dongliang Luo Xufeng Wang cheng Shen ning Wu ning Zhang Binghui Tian Aihong Gai chengdu Institute of Biology Chinese Academy of SciencesChengdu 610041People's Republic of China College of Resources and Environmental Sciences Gansu Agricultural UniversityLanzhou 730070People's Republic of China Mangkang Ecological Monitoring Station Tibet Ecological Security Barrier Ecological Monitoring NetworkQamdo 854500People's Republic of China Northwest Institute of Eco Environmental Resources Chinese Academy of SciencesLanzhou 730000People's Republic of China

Evapotranspiration is an important parameter used to characterize the water cycle of *** under-stand the properties of the evapotranspiration and energy balance of a subalpine forest in the southeastern Qinghai-Tibet Plateau,an open-path eddy covariance system was set up to monitor the forest from November 2020 to October 2021 in a core area of the Three Parallel Rivers in the Qing-hai-Tibet *** results show that the evapotranspira-tion peaked daily,the maximum occurring between 11:00 and 15:*** factors had significant effects on evapotranspiration,among them,net radiation the greatest(R^(2)=0.487),and relative humidity the least(R^(2)=0.001).The energy flux varied considerably in different seasons and sensible heat flux accounted for the main part of turbulent *** energy balance ratio in the dormant season was less than that in the growing season,and there is an energy imbalance at the site on an annual time scale.

关键词： Evapotranspiration Energy balance Subalpine forest Three Parallel Rivers region Southeast Qinghai-Tibet Plateau

Learning-based user association and dynamic resource allocation in multi-connectivity enabled unmanned aerial vehicle networks

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Digital Communications and Networks 2024年第1期10卷 53-62页

作者： Zhipeng cheng Minghui Liwang ning Chen Lianfen Huang Nadra Guizani Xiaojiang Du Department of Information and Communication Engineering Xiamen UniversityXiamen361005China School of Electrical and Computer Engineering University of Texas at ArlingtonArlingtonTX76019USA Department of Electrical and Computer Engineering Stevens Institute of TechnologyHobokenNJ07030USA

Unmanned Aerial Vehicles(UAvs)as aerial base stations to provide communication services for ground users is a flexible and cost-effective paradigm in ***,dynamic resource allocation and multi-connectivity can be adopted to further harness the potentials of UAVs in improving communication capacity,in such situations such that the interference among users becomes a pivotal disincentive requiring effective *** this end,we investigate the Joint UAV-User Association,Channel Allocation,and transmission Power Control(J-UACAPC)problem in a multi-connectivity-enabled UAV network with constrained backhaul links,where each UAV can determine the reusable channels and transmission power to serve the selected ground *** goal was to mitigate co-channel interference while maximizing long-term system *** problem was modeled as a cooperative stochastic game with hybrid discrete-continuous action space.A Multi-Agent Hybrid Deep Reinforcement Learning(MAHDRL)algorithm was proposed to address this *** simulation results demonstrated the effectiveness of the proposed algorithm and showed that it has a higher system utility than the baseline methods.

关键词： UAV-user association Multi-connectivity Resource allocation Power control Multi-agent deep reinforcement learning

Molecular simulation study on the evolution process of hydrate residual structures into hydrate

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Chinese Journal of Chemical Engineering 2024年第5期69卷 79-91页

作者： Liwei cheng Yunfei Li Jinlong Cui Huibo Qin Fulong ning Bei Liu Guangjin Chen Faculty of Engineering China University of GeosciencesWuhan 430074China State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China College of Science Nanchang Institute of TechnologyNanchang 330099China School of Chemical Engineering Guangdong University of Petrochemical TechnologyMaoming 525000China National Center for International Research on Deep Earth Drilling and Resource Development China University of Geosciences(Wuhan)Wuhan 430074China

The clathrate hydrate memory effect is a fascinating phenomenon with potential applications in carbon capture,utilization and storage(CCUS),gas separation,and gas storage as it can accelerate the secondary formation of clathrate ***,the underlying mechanism of this effect remains *** gain a better understanding of the mechanism,we conducted molecular dynamic simulations to simulate the initial formation and reformation processes of methane *** this work,we showed the evolution process of hydrate residual structures into hydrate *** simulation results indicate that the residual structures are closely related to the existence of hydrate memory effect,and the higher the contribution of hydrate dissociated water to the hydrate nucleation process,the faster the hydrate *** hydrate dissociation,the locally ordered structures still exist after hydrate dissociation and can promote the formation of cluster structures,thus accelerating hydrate ***,the nucleation process of hydrate and the formation process of clusters are *** size of clusters composed of cup-cage structures is critical for hydrate *** residence time at high temperature after hydrate decomposition will affect the strength of the hydrate memory *** simulation results provide microscopic insights into the occurrence of the hydrate memory effect and shed light on the hydrate reformation process at the molecular scale.

关键词： Memory effect Molecular simulation Hydrate reformation Residual structures

The effect of seismic action on stability of saline soil subgrade in cold region based on isothermal stratification method

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Earthquake Research Advances 2024年第3期4卷 66-81页

作者： Jie cheng Yu Zhang Ying Ma Xuerui Chen ning An School of Traffic and Transportation Lanzhou Jiaotong UniversityLanzhou730070China Key Laboratory of Railway Industry of Plateau Railway Transportation Intelligent Management and Control Lanzhou Jiaotong UniversityLanzhou730070China Gansu Institute of Engineering Geology Lanzhou730030China

With the change of seasons, the shear strength of saline soil subgrade filler will change with the change of external temperature, which will aggravate the adverse effects of seismic on the subgrade. To explore the influence of seismic action on the stability of saline soil subgrade under the influence of temperature on the strength of saline soil subgrade filler, this paper first carried out saline soil shear tests at different temperatures to obtain the influence of temperature on the shear strength of saline soil. Then, the temperature field of the saline soil subgrade was simulated, and then based on the subgrade isothermal stratification model and FLAC3D, the displacement and acceleration amplification effects of seismic action on the shady slope, sunny slope and subgrade of saline soil subgrade in different months were analyzed. The following conclusions were finally drawn: under the action of seismic, In the process of the change of subgrade temperature of Qarhan-Golmud Expressway between 7.7°C and 27°C, the change of saline soil cohesion is the main factor affecting the stability of subgrade slope, and the maximum and minimum values of subgrade surface settlement appear in September and June of each year,respectively. In August, the differences of settlement between the shady slope and the sunny slope shoulder of the subgrade were the largest, and the acceleration of the shady slope and the sunny slope and the inside of the subgrade changed most significantly in the vertical direction. Special attention should be paid to the seismic early warning in the above key months;In the range from both sides of the shoulder to the centerline of the roadbed,the acceleration amplification effect starts to increase significantly from about 3m from the centerline of the roadbed to the centerline, so it is necessary to pay attention to the seismic design of this range.

关键词： Subgrade stability Saline soils Acceleration amplification effect Seismic design

Late-stage modification of bioactive compounds:Improving druggability through efficient molecular editing

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Acta Pharmaceutica Sinica B 2024年第3期14卷 1030-1076页

作者： Tongyu Huo Xinyi Zhao Zengrui cheng Jialiang Wei Minghui Zhu Xiaodong Dou ning Jiao State Key Laboratory of Natural and Biomimetic Drugs School of Pharmaceutical SciencesPeking UniversityBeijing 100191China Changping Laboratory Beijing 102206China Shanghai Key Laboratory of Green Chemistry and Chemical Processes East China Normal UniversityShanghai 200062China

Synthetic chemistry plays an indispensable role in drug discovery,contributing to hit compounds identification,lead compounds optimization,candidate drugs preparation,and so *** Nobel Prize laureate James Black emphasized,“the most fruitful basis for the discovery of a new drug is to start with an old drug”***-stage modification or functionalization of drugs,natural products and bioactive compounds have garnered significant interest due to its ability to introduce diverse elements into bioactive compounds *** modifications alter the chemical space and physiochemical properties of these compounds,ultimately influencing their potency and *** enrich a toolbox of chemical modification methods for drug discovery,this review focuses on the incorporation of halogen,oxygen,and nitrogen—the ubiquitous elements in pharmacophore components of the marketed drugs—through late-stage modification in recent two decades,and discusses the state and challenges faced in these *** also emphasize that increasing cooperation between chemists and pharmacists may be conducive to the rapid discovery of new activities of the functionalized ***,we hope this review would serve as a valuable resource,facilitating the application of late-stage modification in the construction of novel molecules and inspiring innovative concepts for designing and building new drugs.

关键词： Late-stage modification Drug space Halogenation Oxygenation Nitrogenation Synthetic chemistry