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Effect of geomorphologic features and climate change on vegetation distribution in the arid hot valleys of Jinsha River,Southwest China

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Journal of Mountain Science 2022年第10期19卷 2874-2885页

作者： ZHOU Yang YI Yu-jun LIU hong-xi TANG Cai-hong ZHU Yu-long zhang shang-hong School of Water Resources and Hydropower Engineering North China Electric Power UniversityBeijing 102206China State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBejing 100875China Advanced Institute of Natural Sciences Beijing Normal UniversityZhuhai 519087China

Rapid change of climate in vertical and considerable geomorphologic features form a typical diversity and distribution of biota in mountain ecosystems,i.e.,the subalpine forest zone(SFZ),the valley savanna zone(VSZ),and the transition zone between *** arid hot valley in the middle and lower reaches of Jinsha River,China represents a well target area to study distribution and the driving factors in these typical mountain ***,this study selects four sub-sample areas in the arid-hot valley to explore the distinctive changes of vegetation during 1990 to 2020,and their driving factors in the three different vegetation zones on spatiotemporal *** the spatial scale,the Moran’s index was applied to identify the transition zone between the SFZ and the *** show that the VSZ at low altitudes(less than 600-1000 m from the valley bottom)is mainly affected by geomorphologic features,especially the slope *** increase in altitude,the climate factors(e.g.,humidity,temperature,etc.)play a more significant role in the development of the SFZ,while the effect of geomorphologic features gradually *** the time scale,The SFZ at higher altitudes experienced more rapid changes in temperature(temperature increase of 1.41°C over the last 60 years)than the VSZ at lower altitudes(temperature increase of 0.172°C over the past 60 years).It caused the forest cover increase faster than that of savanna *** and heat conditions are altered by topography and climate conditions,which shapes the development and physiology of plants as they adapt to the different climatic ***,according to the driving factors(geomorphologic and climate factors)of vegetation distribution found in this study,it suggests that suitable tree species should be planted in the transition zone to evolve into the forest zone and making the forest zone to recover from high to low altitudes gradually.

关键词： Mountain vegetation distribution Subalpine forest zone Valley savanna zone Geomorphologic features Climate change

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High-precision parallel computing model of solute transport based on GPU acceleration

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Journal of Hydrodynamics 2024年第1期36卷 202-212页

作者： shang-hong zhang Rong-qi zhang Wen-da Li Xi-yan Yang Yang Zhou School of Water Resources and Hydropower Engineering North China Electric Power UniversityBeijing102206China Hubei Key Laboratory of Intelligent Yangtze and Hydroelectric Science China Yangtze Power Co.Ltd.Yichang443133China

The scenario simulation analysis of water environmental emergencies is very important for risk prevention and control,and emergency *** quickly and accurately simulate the transport and diffusion process of high-intensity pollutants during sudden environmental water pollution events,in this study,a high-precision pollution transport and diffusion model for unstructured grids based on Compute Unified Device Architecture(CUDA)is *** finite volume method of a total variation diminishing limiter with the Kong proposed r-factor is used to reduce numerical diffusion and oscillation errors in the simulation of pollutants under sharp concentration conditions,and graphics processing unit acceleration technology is used to improve computational *** advection diffusion process of the model is verified numerically using two benchmark cases,and the efficiency of the model is evaluated using an engineering *** results demonstrate that the model perform well in the simulation of material transport in the presence of sharp ***,it has high computational *** acceleration ratio is 46 times the single-thread acceleration effect of the original *** efficiency of the accelerated model meet the requirements of an engineering application,and the rapid early warning and assessment of water pollution accidents is achieved.

关键词： Pollution transport and diffusion model parallel computing Compute Unified Device Architecture(CUDA) pollution event

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Operando measurement of lattice deformation profiles of synchrotron radiation monochromator

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Nuclear Science and Techniques 2024年第7期35卷 8-19页

作者： Yue zhang Zhong-Liang Li shang-Yu Si Lian Xue hong-Xin Luo Xiao-Wei zhang Jun Hu shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai201204China shanghaiTech University Shanghai201210China University of the Chinese Academy of Sciences Beijing100049China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of ScienceBeijing100049China

This study presents a new method for characterizing the thermal lattice deformation of a monochromator with high precision under service conditions and first reports the operando measurements of nanoscale thermal lattice deformation on a double-crystal monochromator at different incident *** nanoscale thermal lattice deformation of the monochromator first crystal was obtained by analyzing the intensity of the distorted DuMond *** diagrams of the 333 diffraction index,sensitive to lattice deformation,were obtained directly using a 2D detector and an analyzer crystal orthogonal to the *** increasing incident power and power density,the maximum height of the lattice deformation increased from 3.2 to 18.5 nm,and the deformation coefficient of the maximum height increased from 1.1 to 3.2 nm/*** maximum relative standard deviation was 4.2%,and the maximum standard deviation was 0.1 *** on the measured thermal deformations,the flux saturation phenomenon and critical point for the linear operation of the monochromator were predicted with increasing incident *** study provides a simple solution to the problem of the lower precision of synchrotron radiation monochromator characterizations compared to simulations.

关键词： Synchrotron radiation Monochromator Lattice deformation X-ray dynamic diffraction

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Review on Security Defense Technology Research in Edge Computing Environment

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Chinese Journal of Electronics 2024年第1期33卷 1-18页

作者： Ke shang Weizhen HE Shuai zhang National Digital Switching System Engineering and Technological R&D Center

Edge computing, which achieves quick data processing by sinking data computing and storage to the network edge, has grown rapidly along with the Internet of things. The new network architecture of edge computing brings new security challenges. Based on this, this paper investigates the edge computing security literature published in recent years and summarizes and analyzes research work on edge computing security from different attack surfaces. We start with the definition and architecture of edge computing. From the attack surface between device and edge server, as well as on edge servers, the research describes the security threats and defense methods of edge computing. In addition, the cause of the attack and the pros and cons of defense methods is introduced. The challenges and future research directions of edge computing are given.

关键词： Cloud computing Systems architecture Computer architecture Network architecture Data processing Security Servers

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Target parameter estimation for OTFS-integrated radar and communications based on sparse reconstruction preprocessing

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Frontiers of Information Technology & Electronic Engineering 2024年第5期25卷 742-754页

作者： Zhenkai zhang Xiaoke shang Yue XIAO Ocean College Jiangsu University of Science and TechnologyZhenjiang 212003China

Orthogonal time-frequency space(OTFS)is a new modulation technique proposed in recent years for high Doppler wireless *** solve the parameter estimation problem of the OTFS-integrated radar and communications system,we propose a parameter estimation method based on sparse reconstruction preprocessing to reduce the computational effort of the traditional weighted subspace fitting(WSF)***,an OTFS-integrated echo signal model is ***,the echo signal is transformed to the time domain to separate the target angle from the range,and the range and angle of the detected target are coarsely estimated by using the sparse reconstruction ***,the WSF algorithm is used to refine the search with the coarse estimate at the center to obtain an accurate *** simulations demonstrate the effectiveness and superiority of the proposed parameterestimation algorithm.

关键词： Integrated radar and communications system Orthogonal time-frequency space Target parameter estimation Sparse reconstruction Weighted subspace fitting

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Activation and coreceptor expression of T lymphocytes induced by highly active antiretroviral therapy in Chinese HIV/AIDS patients

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Chinese Medical Journal 2006年第23期119卷 1966-1971页

作者： zhang Zi-ning shang hong JIANG Yong-jun LIU Jing DAI Di DIAO Ying-ying GENG Wen-qing JIN Xin WANG Ya-nan Key Laboratory of Immunology of AIDS Ministry of Health FirstAffiliated Hospital China Medical University Shenyang 110001China

Background At the end of 2005, 650 000 people lived with human immunodeficiency virus type-1 （HIV-1） in China, of whom 75 000 were AIDS patients. Many AIDS patients received highly active antiretroviral therapy （HAART） supported by the ＂China CARES＂ program but the immune responses of HAART were seldom reported. This study investigated the effect of HAART on the activation and coreceptor expression of T lymphocytes in Chinese HIV/AIDS patients and evaluated its effect on immune reconstitution. Methods Seventeen HIV/AIDS patients were enrolled and three-color-flow cytometry was used to detect the activation of HLA-DR CD38 and the coreceptor CCR5, CXCR4 expression on T lymphocytes in whole blood samples taken from the patients before and after 3- or 6-month HAART. Results The activation percents of CD4^＋, CD8^＋ T lymphocytes were significantly higher before therapy than the normal controls （HLA-DR/CD4： 40.47±18.85 vs 11.54±4.10; CD38/CD4： 81.34± 10.86 vs 53.34± 11.44; HLA-DR/CD8：63.94±12.71 vs 25.67±9.18; CD38/CD8： 86.56± 11.41 vs 58.84±6.16,. all P〈0.01）. After 6-month combined antiretroviral treatment, the activation of T lymphocytes in HIV/AIDS patients was significantly decreased （HLA-DR/CD4：28.31± 13.48; CD38/CD4：69.88 ± 12.64; HLA-DR/CD8： 46.56± 18.64; CD38/CD8： 70.17±14.54, all P〈0.01 compared with the pre-treatment values）. Before the treatment, CCR5 expression on CD8^＋ T lymphocytes was up-regulated while CXCR4 expression on CD8^＋ T lymphocytes downregulated in HIV/AIDS patients compared with the normal controls （CD8/CCR5：70.91 ± 10.03 vs 52.70± 7.68; CD8/CXCR4：24.14±11.08 vs 50.05±11.68, all P〈0.01）. After 6-month HAART, CCR5 expression on CD8^＋ T lymphocytes significantly decreased （56.35±2.96, P〈0.01）, while CXCR4 expression on CD8^＋ T lymphocytes increased （36.95±9.96, P〈0.05） compared with the pre-treatment and the normal controls. A significant statistical relationship was observed between the expression of activation markers, CCR5 and the CD4^＋ T lym

关键词： human immunodeficiency virus type-l antiretroviral therapy, highly active T-lymphocytes activation analysis

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Effectiveness of urban distributed runoff model for discharge and water depth calculation in urban drainage pipe networks

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Journal of Hydrodynamics 2024年第3期36卷 582-591页

作者： Yang Zhou Yi-ling Leng Peng-yu Wang shang-hong zhang Yu-long Zhu Yu-jun Yi School of Water Resources and Hydropower Engineering North China Electric Power UniversityBeijing102206China State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing100875China

Effective urban land-use re-planning and the strategic arrangement of drainage pipe networks can significantly enhance urban flood defense *** at reducing the potential risks of urban flooding,this paper presents a straightforward and efficient approach to an urban distributed runoff model(UDRM).The model is developed to quantify the discharge and water depth within urban drainage pipe networks under varying rainfall intensities and land-use *** Nash efficiency coefficient of UDRM exceeds 0.9,which indicates its high computational efficiency and potential benefit in predicting urban *** prediction of drainage conditions under both current and re-planned land-use types is achieved by adopting different flood recurrence *** findings reveal that the re-planned land-use strategies could effectively diminish flood risk upstream of the drainage pipe network across 20-year and 50-year flood recurrence ***,in the case of extreme rainfall events(a 100-year flood recurrence),the re-planned land-use approach fell short of fulfilling the requirements necessary for flood disaster *** these instances,the adoption of larger-diameter drainage pipes becomes an essential requisite to satisfy drainage ***,the proposed UDRM effectively combines land-use information with pipeline data to give practical suggestions for pipeline modification and land-use optimization to combat urban ***,this methodology warrants further promotion in the field of urban re-planning.

关键词： Stormwater runoff water depth urban distributed runoff model urban drainage pipe networks urban land-use re-planning

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Highly cycle-stable VOPO_(4)-based cathodes for magnesium ion batteries:Insight into the role of interlayer engineering in batteries performance

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Nano Research 2024年第7期17卷 6127-6138页

作者： Jiahe zhang Jing shang Xiaojun zhang Ke Wang Yihe zhang Engineering Research Center of Ministry of Education for Geological Carbon Storage and Low Carbon Utilization of Resources Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid WastesNational Laboratory of Mineral MaterialsSchool of Materials Science and TechnologyChina University of Geosciences(Beijing)Beijing 100083China

It is the sluggish ion migration kinetics that seriously affects the practical performance of the magnesium ion *** though an electrode material design using rational interlayer engineering method could effectively solve this issue,the optimal interlayer distance remains ***,various VOPO_(4)-based electrodes with expanded interlayer spacing were fabricated and the relationship between interlayer structure and battery performance was *** analysis combined with computations unveils the existence of an optimal interlayer structure,as inadequate expansion failed to fully utilization of the material performance,while excessive expansion degraded the electrode *** them,the electrode with triethylene glycol(TEG)intercalation exhibited optimized performance,maintaining excellent cycling stability(191.3 mAh·g^(−1)after 800 cycles).Density functional theory(DFT)demonstrated the effectiveness and limitations to lowering the migration energy barrier by expanding the interlayer *** addition,systematic mechanism research revealed the Mg^(2+)storage process:The stepwise shuttling of Mg^(2+)along the directions that lie in(001)plane triggers two pairs of redox processes,namely V^(5+)/V^(4+)and V^(4+)/V^(3+).This study,regulation of layer spacing to achieve the best integrated performance of electrodes,could deepen the understanding of interlayer engineering and guide the design of advanced multivalent-ion batteries.

关键词： magnesium ion batteries layered electrodes interlayer engineering energy storage mechanisms high kinetics

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Unveiling the Contribution of Lactic Acid to the Passivation Behavior of Ti-6Al-4V Fabricated by Laser Powder Bed Fusion in Hank’s Solution

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 102-118页

作者： Yu-Hang Chu Liang-Yu Chen Bo-Yuan Qin Wenbin Gao Fanmin shang hong-Yu Yang Lina zhang Peng Qin Lai-Chang zhang School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang212100China Foshan(Southern China)Institute for New Materials Foshan528200China Key Laboratory of Automobile Materials Ministry of Education and Department of Materials Science and EngineeringJilin UniversityChangchun130025China Centre for Advanced Materials and Manufacturing School of EngineeringEdith Cowan University270 Joondalup DriveJoondalupPerthWA6027Australia

In actual physiological environments,bacteria can activate the immune system and release lactic ***,the detailed contribution of lactic acid to the passivation behavior of titanium(Ti)alloys is still *** current work investigated the in vitro passivation behavior of Ti-6Al-4V(TC4)alloys fabricated by laser powder bed fusion in Hank's solution with and without adding lactic *** methods,inductively coupled plasma atomic emission spectrometer,and X-ray photoelectron spectroscopy were jointly *** lactic acid decreases the corrosion resistance of samples by degrading the formed passive *** film formed in the(lactic acid)-containing solution exhibits a higher level of oxygen vacancies and a lower thickness,attributed to the suppressed formation of Ti^(4+)transformed from Ti^(3+)and Ti^(2+).Moreover,the presence of lactic acid would increase the open circuit potential,relieve the ions release,and hinder the deposition of calcium phosphates within 24 h immersion.

关键词： Titanium alloy Corrosion behavior Passive film Lactic acid Laser powder bed fusion

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Capacity Market Mechanism Design,Considering Network Optimization and Energy Transition

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1676-1687页

作者： Nan shang Yihang Song Xiang zhang You Lin China Southern Power Grid Co. Ltd.Guangzhou 510663China Southern Methodist University Junkins 3086251 Airline Road DallasTX 75205US

The coordination of enrgy transition,fixed cost recovery,and sufficient generation supply leads to a new challenge for a traditional capacity market ***,in order to better match network expansion at the same time,it is crucial to redesign the capacity market mechanism considering system *** this paper,a novel capacity market mechanism is proposed considering spot market operations,network expansion,and energy transition,which can minimize the total cost of capacity investment,network expansion,and generation operations,while satisfying the energy transition constraints and topology ***,the capacity market mechanism co-ordinated with spot market operations is illustrated,in which the energy transition and network constraints are ***,a bi-level optimization model is established where the trade organizers minimize the total cost of both investment and operations,subject to the spot power market simultaneously minimizing the local dispatching *** numerical results of a test system show that more economical capacity portfolios can be obtained by constructing reasonable transmission lines,thereby obtaining a more optimal market cost.A detailed multi-scenario simulation is further analyzed to verify the effectiveness of the proposed market mechanism.

关键词： Capacity market energy transition network expansion spot market operation

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