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锂离子电池负极材料ZnSnO_(3)/C复合物的制备与性能

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工程科学学报 2024年第1期46卷 81-88页

作者：岳红伟邢若冰耿壮壮铁伟伟朱聪旭谢文合陈淑君许昌学院化工与材料学院许昌461000 信阳师范学院物理电子工程学院信阳464000

锡基双金属氧化物作为锂离子电池负极材料因具有高的理论比容量、嵌脱锂电位适中、储量丰富、价格低廉、安全性高以及环保等优点,已经受到了广泛的关注.本研究采用一步原位水热法制备了碳包覆的ZnSnO_(3)复合材料(ZnSnO_(3)/C).利用扫... 详细信息

锡基双金属氧化物作为锂离子电池负极材料因具有高的理论比容量、嵌脱锂电位适中、储量丰富、价格低廉、安全性高以及环保等优点,已经受到了广泛的关注.本研究采用一步原位水热法制备了碳包覆的ZnSnO_(3)复合材料(ZnSnO_(3)/C).利用扫描电子显微镜、透射电子显微镜、X射线衍射、拉曼光谱、X射线光电子能谱分析和恒流充放电测试等一系列表征测试方法对材料的微观形貌、物相组成、结构和电化学性能进行分析.电化学测试结果表明:当作为锂离子电池负极材料时,ZnSnO_(3)/C复合电极的储锂性能优于纯ZnSnO_(3)电极.在200 mA·g^(-1)电流密度下,ZnSnO_(3)/C复合电极经200次循环后可逆容量可达1274.9 mA·h·g^(-1),即使在大电流5000 mA·g^(-1)下经500次循环仍然提供663.2 mA·h·g^(-1)的放电比容量,同时也表现出卓越的倍率性能.优异的储量性能归因于ZnSnO_(3)/C复合材料中具有高电导率的C不仅提高了整个电极的导电性,有利于电子的传输,而且增大了电解液与活性材料之间的接触面积,缩短了锂离子的扩散距离;同时碳包覆层可有效缓冲ZnSnO_(3)在嵌脱锂过程中由于体积变化产生的应力,也能在一定程度上抑制ZnSnO_(3)在循环过程中的团聚.

关键词：锡酸锌碳复合材料负极锂离子电池

Deep structure of the Southeast Asian curved subduction system and its dynamic process

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Journal of Oceanology and Limnology 2024年第3期42卷 701-704页

作者： weiwei DING Key Laboratory of Submarine Geoscience&Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200030China

The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical *** on the deep seismic tomography using long-period natural earthquake data,in this study,the deep structure and material circulation of the curved subduction system in Southeast Asia was studied,and the dynamic processes since 100 million years ago was *** is pointed out that challenges still exist in the precise reconstruction of deep mantle structures of the study area,the influence of multi-stage subduction on deep material exchange and shallow magma activity,as well as the spatiotemporal evolution and coupling mechanism of multi-plate *** work should focus on high-resolution land-sea joint 3-D seismic tomography imaging of the curved subduction system in the Southeast Asia,combined with geochemical analysis and geodynamic modelling works.

关键词： curved subduction system deep structure material recycling dynamic process Southeast Asia

Loss-of-function mutation of rice SLAC7 decreases chloroplast stability and induces a photoprotection mechanism in rice

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Journal of Integrative Plant Biology 2015年第12期57卷 1063-1077页

作者： Xiaolei Fan Jiemin Wu Taiyu Chen weiwei tie Hao Chen Fei Zhou Yongjun Lin National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research Huazhong Agricultural University Institute of Tropical Bioscience and Biotechnology Chinese Academy of Tropical Agricultural Sciences

Plants absorb sunlight to power the photochem- ical reactions of photosynthesis, which can potentially damage the photosynthetic machinery. However, the mech- anism that protects chloroplasts from the damage remains unclear. In this work, we demonstrated that rice （Oryza sativa L.） SLAC7 is a generally expressed membrane protein. Loss- of-function of SLAC7 caused continuous damage to the chloroplasts of mutant leaves under normal light conditions. Ion leakage indicators related to leaf damage such as H^O2 and abscisic acid levels were significantly higher in slac7-1 than in the wild type. Consistently, the photosynthesis efficiency and Fv/Fm ratio of slac7-1 were significantly decreased （similar to photoinhibition）. In response to chloroplast damage, slat7- 1 altered its leaf morphology （curled or fused leaf） by the synergy between plant hormones and transcriptional factors to decrease the absorption of light, suggesting that a photoprotection mechanism for chloroplast damage was activated in slac7-1. When grown in dark conditions, slac7-1 displayed a normal phenotype. 5LAC7 under the control of the AtSLAC1 promoter could partially complement thephenotypes of Arabidopsis slacl mutants, indicating a partial conservation of SLAC protein functions. These results suggest that SLAC7 is essential for maintaining the chloroplast stability in rice.

关键词： Anion transport chloroplast cytokinin Oryza sativa L photoinhibition SLAC1

A Server Placement Algorithm for Reducing Risk and Improving Power Utilization in Data Centers

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Tsinghua Science and Technology 2024年第1期29卷 158-173页

作者： Rui Chen Huikang Huang Xiaoxuan Luo weiwei Lin School of Computer Science and Engineering South China University of TechnologyGuangzhou 510006China Peng Cheng Laboratory Shenzhen 518066China

As the power demand in data centers is increasing,the power capacity of the power supply system has become an essential resource to be *** many data centers use power oversubscription to make full use of the power capacity,there are unavoidable power supply risks associated with ***,how to improve the data center power capacity utilization while ensuring power supply security has become an important *** solve this problem,we first define it and propose a risk evaluation metric called Weighted Power Supply Risk(WPSRisk).Then,a method,named Hybrid Genetic Algorithm with Ant Colony System(HGAACS),is proposed to improve power capacity utilization and reduce power supply risks by optimizing the server placement in the power supply *** uses historical power data of each server to find a better placement solution by population *** possesses not only the remarkable local search ability of Ant Colony System(ACS),but also enhances the global search capability by incorporating genetic operators from Genetic Algorithm(GA).To verify the performance of HGAACS,we experimentally compare it with five other placement *** experimental results show that HGAACS can perform better than other algorithms in both improving power utilization and reducing the riskof powersupply system.

关键词： server placement power utilization power supply risk swarm intelligence algorithm

Microearthquake reveals the lithospheric structure at midocean ridges and oceanic transform faults

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Journal of Oceanology and Limnology 2024年第3期42卷 697-700页

作者： Zhiteng YU Jiabiao LI weiwei DING Key Laboratory of Submarine Geosciences&Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China

Mid-ocean ridge and oceanic transforms are among the most prominent features on the seafloor surface and are crucial for understanding seafloor spreading and plate tectonic dynamics,but the deep structure of the oceanic lithosphere remains poorly *** large number of microearthquakes occurring along ridges and transforms provide valuable information for gaining an indepth view of the underlying detailed seismic structures,contributing to understanding geodynamic processes within the oceanic *** studies have indicated that the maximum depth of microseismicity is controlled by the 600-℃***,this perspective is being challenged due to increasing observations of deep earthquakes that far exceed this suggested isotherm along mid-ocean ridges and oceanic transform *** mechanisms have been proposed to explain these deep events,and we suggest that local geodynamic processes(e.g.,magma supply,mylonite shear zone,longlived faults,hydrothermal vents,etc.)likely play a more important role than previously thought.

关键词： microearthquake mid-ocean ridge oceanic transform fault oceanic lithosphere thermal structure earthquake location

Cooperative Covert Communication in Multi-Antenna Broadcast Channels

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China Communications 2024年第6期21卷 246-260页

作者： Qiao Sen Liu Guangjie Ji Xiaopeng Liu weiwei School of Electrical and Information Engineering Nanjing University of Information Science and TechnologyNanjing 210044China School of Automation Nanjing University of Science and TechnologyNanjing 210094China

With the gradual popularization of 5G communications,the application of multi-antenna broadcasting technology has become ***,this study aims to investigate the wireless covert communication in the two-user cooperative multi-antenna broadcast *** focus on the issue that the deteriorated reliability and undetectability are mainly affected by the transmission *** tackle this issue,we design a scheme based on beamforming to increase the reliability and undetectability of wireless covert communication in the multi-antenna broadcast *** first modeled and analyzed the cooperative multi-antenna broadcasting system,and put forward the target *** we use the SCA(successive convex approximation)algorithm to transform the target problem into a series of convex *** the convex problems are solved and the covert channel capacity is *** order to verify the effectiveness of the scheme,we conducted simulation *** simulation results show that the proposed beamforming scheme can effectively improve the reliability and undetectability of covert communication in multi-antenna broadcast channels.

关键词： beamforming covert communication multi-antenna broadcast channels OFDM

Heterogeneous data-driven aerodynamic modeling based on physical feature embedding

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Chinese Journal of Aeronautics 2024年第3期37卷 1-6页

作者： weiwei ZHANG Xuhao PENG Jiaqing KOU Xu WANG School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Institute of Aerodynamics RWTH Aachen UniversityAachen 52062Germany

Aerodynamic surrogate modeling mostly relies only on integrated loads data obtained from simulation or experiment,while neglecting and wasting the valuable distributed physical information on the *** make full use of both integrated and distributed loads,a modeling paradigm,called the heterogeneous data-driven aerodynamic modeling,is *** essential concept is to incorporate the physical information of distributed loads as additional constraints within the end-to-end aerodynamic *** heterogenous data,a novel and easily applicable physical feature embedding modeling framework is *** framework extracts lowdimensional physical features from pressure distribution and then effectively enhances the modeling of the integrated loads via feature *** proposed framework can be coupled with multiple feature extraction methods,and the well-performed generalization capabilities over different airfoils are verified through a transonic *** with traditional direct modeling,the proposed framework can reduce testing errors by almost 50%.Given the same prediction accuracy,it can save more than half of the training ***,the visualization analysis has revealed a significant correlation between the discovered low-dimensional physical features and the heterogeneous aerodynamic loads,which shows the interpretability and credibility of the superior performance offered by the proposed deep learning framework.

关键词： Transonic flow Data-driven modeling Feature embedding Heterogenous data Feature visualization

Distributed Fault Estimation for Nonlinear Systems With Sensor Saturation and Deception Attacks Using Stochastic Communication Protocols

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IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1865-1876页

作者： weiwei Sun Xinci Gao Lusong Ding Xiangyu Chen Institute of Automation Qufu Normal UniversityQufu 273165China

This paper is aimed at the distributed fault estimation issue associated with the potential loss of actuator efficiency for a type of discrete-time nonlinear systems with sensor *** the distributed estimation structure under consideration,an estimation center is not necessary,and the estimator derives its information from itself and neighboring nodes,which fuses the state vector and the measurement *** an effort to cut down data conflicts in communication networks,the stochastic communication protocol(SCP)is employed so that the output signals from sensors can be ***,a recursive security estimator scheme is created since attackers randomly inject malicious signals into the selected *** this basis,sufficient conditions for a fault estimator with less conservatism are presented which ensure an upper bound of the estimation error covariance and the mean-square exponential boundedness of the estimating ***,a numerical example is used to show the reliability and effectiveness of the considered distributed estimation algorithm.

关键词： Actuator fault deception attacks distributed estimation sensor saturation stochastic communication protocol(SCP).

Energy-absorbing porous materials:Bioinspired architecture and fabrication

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Nano Research 2024年第2期17卷 679-690页

作者： Junheng Zhao Meng Li Jiewei Chen weiwei Gao Hao Bai State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310058China Department of Polymer Science and Engineering Zhejiang UniversityHangzhou 310058China

Energy-absorbing materials are widely used in transportations,sports,and the military ***,porous materials,including natural and artificial materials,have attracted tremendous attentions due to their light weight and excellent energy absorption *** review summarizes the recent progresses in the natural and artificial energy-absorbing porous ***,we review the typical natural porous materials including cuttlebone,bighorn sheep horn,pomelo peel,and sunflower stem *** architectures,energy absorption abilities,and mechanisms of these typical natural materials and their bioinspired materials are ***,we provide a review on the fabrication methods of artificial energy-absorbing porous materials,such as conventional foaming and three-dimensional(3D)***,we address the challenges and prospects for the future development of energy-absorbing porous *** importantly,our review provides a direct guidance for the design and fabrication of energy-absorbing porous materials required for various engineering applications.

关键词： energy-absorbing porous materials natural materials natural structures bioinspired materials