检索结果-南通市图书馆

Journal of Integrative Plant Biology 2009年第4期51卷 423-432页

作者： Qing-Ming Sun Rong-Hua Zhou Li-Feng Gao guang-yao zhao Ji-Zeng Jia College of Biological Sciences China Agricultural University Beijing 100094 China Department of Crop Molecular Biology Institute of Crop Sciences Chinese Academy of Agricultural Sciences Beijing 100081 China

The frequency and distribution of the major vernalization requirement genes and their effects on growth habits were studied. Of the 551 bread wheat genotypes tested, seven allelic combinations of the three Vrn-1 genes were found to be responsible for the spring habit, three for the facultative habit and one for the winter habit. The three Vrn-1 genes behaved additiveiy with the dominant allele of Vrn-A1 exerting the strongest effect. The allele combinations of the facultative genotypes and the discovery of spring genotypes with ＂winter＂ allele of Vrn-1 implied the presence of as yet unidentified alleles/genes for vernalization response. The dominant alleles of the three Vrn-1 genes were found in all ten ecological regions where wheat is cultivated in China, with Vrn-D1 as the most common allele in nine and Vrn-A1 in one. The combination of vrn-A1vrn-B1Vrn-D1 was the predominant genotype in seven of the regions. Compared with landraces, improved varieties contain a higher proportion of the spring type. This was attributed by a higher frequency of the dominant Vrn-A1 and Vrn-B1 alleles in the latter, Correlations between Vrn-1 allelic constitutions and heading date, spike length, plant type as well as cold tolerance were established.

关键词： common wheat genotyping geographical distribution vernalization.

Cycling hydrogen desorption properties and microstructures of MgH_(2)-AlH_(3)-NbF_(5) hydrogen storage materials

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2021年第4期40卷 1003-1007页

作者： Xiao-Sheng Liu Hai-Zhen Liu Ning Qiu Yan-Bing Zhang guang-yao zhao Li Xu Zhi-Qiang Lan Jin Guo guangxi Novel Battery Materials Research Center of Engineering Technology School of Physical Science and TechnologyGuangxi UniversityNanning 530004China guangxi Key Laboratory of Processing for Non-ferrous Metallic and Featured Materials School of Physical Science and TechnologyGuangxi UniversityNanning 530004China guangxi Colleges and Universities Key Laboratory of Novel Energy Materials and Related Technology School of Physical Science and TechnologyGuangxi UniversityNanning 530004China State Key Laboratory of Advanced Power Transmission Technology Global Energy Interconnection Research Institute Co.LtdBeijing 102209China Department of AC Construction State Grid Co.LtdBeijing 100031China State Grid DC Project Construction Branch Company Beijing 100052China

Magnesium hydride(MgH_(2)) is a candidate material for hydrogen ***_(2)-AlH_(3) composite shows superior hydrogen desorption properties than pure MgH_(2).However,this composite still suffers from poor cycling *** this work,NbF_(5) was utilized to improve the cycling properties of the MgH_(2)-AlH_(3) *** hydrogen desorption studies show that NbF_(5) significantly improves the cycling stability of MgH_(2)-AlH_(3).The MgH_(2)-AlH_(3)-NbF_(5) composite can release about 2.7 wt% of hydrogen at 300℃ for 1 h and the hydrogen desorption capacity can maintain at 2.7 wt% for more than100 *** comparison,the hydrogen desorption capacity of the MgH_(2)-AlH_(3) composite is decreasing with the cycle number *** capacity is reduced from a maximum value of 3.3 wt% to about 1.0 wt% after 40 ***-Emmett-Teller(BET) surface area measurements show that the particle size of MgH_(2)-AlH_(3) composite decreases after cycling,which means pulverization of the ***_(5) can to some extent suppress the pulverization of the composite during cycling,which partially contributes to the improvement of the cycling hydrogen desorption properties of the material.

关键词： Hydrogen storage materials Magnesium hydride Aluminum hydride Niobium fluoride Cycling properties

Limits of Uneven Battery Power in Modular Multilevel Converter-based Battery Energy Storage Systems

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第2期10卷 686-695页

作者： yao Pan Xiaofeng Sun Wei zhao Xin Li yao Cai Institute of Electrical Engineering Yanshan UniversityQinhuangdao 066004China

For modular multilevel converter-based battery energy storage systems (MMC-BESS), uneven power among batteries of SMs will be deduced by battery aging, battery fault, etc., which will degrade performance and even lead to system failure. For maintaining the balance of capacitor voltage, this paper analyzes the limits of the uneven power of batteries, which are presented as the current limits in this paper. According to analysis, an analytical method is proposed that only the dc and fundamental frequency components of the arm current are used to calculate current limits. With the current limits it is able to evaluate the reasonability of power distribution among batteries. Meanwhile, increase of fundamental frequency component will enhance the current limits, and the dc component determines the size relationship between the absolute values of the upper and lower current limits. Finally, simulation model and experiment prototype are built for verifying the theoretical analysis and current limits calculation method, and satisfactory results are provided.

关键词： Arm current balance of capacitor voltage current limits MMC-BESS uneven power

State estimation for delayed switched positive systems: delayed radius approach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第8期67卷 190-205页

作者： Weizhong CHEN Zhongyang FEI Xudong zhao Zheng-guang WU School of Electronics and Information Xi'an Polytechnic University Research Institute of Intelligent Control and Systems Harbin Institute of Technology Key Laboratory of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education Dalian University of Technology School of Control Science and Engineering Dalian University of Technology State Key Laboratory of Industrial Control Technology Institute of Cyber-Systems and ControlZhejiang University

In this paper, an interval estimation scheme is developed for delayed switched positive systems（DSPS） with mode-dependent average dwell time switching. A lossless zonotopic estimation approach is proposed for the delayed intersection zonotope with the positive generator matrix. First, considering the existence of asynchronism between the system mode and the correction matrix mode, the mismatched intersection zonotope is constructed for DSPS to verify the consistency between the system model and ***, by utilizing the introduced radius definitions, the ?∞performance is addressed to optimize the size of delayed intersection zonotopes. Subsequently, we present a joint-design approach of switching signals and the mode-dependent correction matrix by constructing positive generator matrix-based delayed radius functions. Furthermore, guaranteed nonnegative state bounds are derived for the considered DSPS based on the proposed lossless zonotopic estimation criteria. Finally, detailed simulations are conducted to validate the feasibility and superiority of the developed methods.

关键词： delayed switched positive systems interval estimation asynchronous correction matrix zonotopes mode-dependent average dwell time

Event-Triggered Bipartite Consensus Tracking and Vibration Control of Flexible Timoshenko Manipulators Under Time-Varying Actuator Faults

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1190-1201页

作者： Xiangqian yao Hao Sun Zhijia zhao Yu Liu School of Automation Science and Engineering South China University of TechnologyGuangzhou 510640China Yongjiang Laboratory Ningbo 315202 School of Astronautics Harbin Institute of TechnologyHarbin 150001China School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou 510006China

For bipartite angle consensus tracking and vibration suppression of multiple Timoshenko manipulator systems with time-varying actuator faults,parameter and modeling uncertainties,and unknown disturbances,a novel distributed boundary event-triggered control strategy is proposed in this *** contrast to the earlier findings,time-varying consensus tracking and actuator defects are taken into account *** addition,the constructed event-triggered control mechanism can achieve a more flexible design because it is not required to satisfy the input-to-state *** achieve the control objectives,some new integral control variables are given by using back-stepping technique and boundary ***,adaptive neural networks are applied to estimate system *** the proposed event-triggered scheme,control inputs can reduce unnecessary ***,tracking errors and vibration states of the closed-looped network can be exponentially convergent into some small fields,and Zeno behaviors can be *** last,some simulation examples are given to state the effectiveness of the control algorithms.

关键词： Vibration satisfy bipartite

Electromagnetic fields in ultra-peripheral relativistic heavy-ion collisions

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第2期35卷 103-109页

作者： Jie zhao Jin-Hui Chen Xu-guang Huang Yu-Gang Ma Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics NSFC and Fudan UniversityShanghai 200438China Physics Department and Center for Particle Physics and Field Theory Fudan UniversityShanghai 200438China

Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic *** these collisions,highly charged fast-moving ions carry strong electromagnetic fields that can be effectively treated as photon *** exchange of photons can induce photonuclear and two-photon interactions and excite *** excitation of the ions results in Coulomb dissociation with the emission of photons,neutrons,and other ***,the electromagnetic fields generated by the ions can be sufficiently strong to enforce mutual interactions between the two colliding ***,the two colliding ions experience an electromagnetic force that pushes them in opposite directions,causing a back-to-back correlation in the emitted *** a Monte Carlo simulation,we qualitatively demonstrate that the above electromagnetic effect is large enough to be observed in UPCs,which would provide a clear means to study strong electromagnetic fields and their effects.

关键词： Electromagnetic fields Neutrons Ultra-peripheral relativistic heavy-ion collisions(UPC)

Applying deep learning technique to chiral magnetic wave search

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第8期48卷 170-176页

作者： Yuan-Sheng zhao Xu-guang Huang Physics Department and Center for Particle Physics and Field Theory Fudan UniversityShanghai 200433China Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Fudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics National Natural Science Foundation of China and Fudan UniversityShanghai 200438China

The chiral magnetic wave(CMW)is a collective mode in quark-gluon plasma originated from the chiral magnetic effect(CME)and chiral separation *** detection in heavy-ion collisions is challenging owing to significant background ***[*** et al.,***.C 106,L051901(2022)],we constructed a neural network that accurately identifies the CME-related signal from the final-state pion *** this study,we have generalized this neural network to the case of CMW *** show that,after an updated training,the neural network effectively recognizes the CMW-related ***,we have assessed the performance of the neural network in comparison with other known methods for CMW search.

关键词： deep learning chiral magnetic wave relativistic heavy-ion collisions

Fracture propagation and evolution law of indirect fracturing in the roof of broken soft coal seams

在线全文

学校读者我要写书评

暂无评论

International Journal of Coal Science & Technology 2024年第1期11卷 78-102页

作者： Haifeng zhao Pengyue Li Xuejiao Li Wenjie yao College of Petroleum Engineering China University of Petroleum(Beijing)Beijing102249China Oil and Gas Exploration Company Shanxi Yanchang Petroleum(Group)Co.LTDYan’an716000China

Indirect fracturing in the roof of broken soft coal seams has been demonstrated to be a feasible *** this work,the No.5 coal seam in the Hancheng block was taken as the research *** on the findings of true triaxial hydraulic fracturing experiments and field pilot under this technology and the cohesive element method,a 3D numerical model of indirect fracturing in the roof of broken soft coal seams was established,the fracture morphology propagation and evolution law under different conditions was investigated,and analysis of main controlling factors of fracture parameters was conducted with the combination weight method,which was based on grey incidence,analytic hierarchy process and entropy weight *** results show that“士”-shaped fractures,T-shaped fractures,cross fractures,H-shaped fractures,and“干”-shaped fractures dominated by horizontal fractures were *** parameter combinations can form different fracture *** the coal seam permeability is lower and the minimum horizontal principal stress difference between layers and fracturing fluid injection rate are both larger,it tends to form“士”-shaped *** the coal seam permeability and minimum horizontal principal stress between layers and perforation position are moderate,cross fractures are easily *** fracture parameters have different main controlling *** factors of perforation location,fracturing fluid injection rate and viscosity are the dominant factors of hydraulic fracture shape *** study can provide a reference for the design of indirect fracturing in the roof of broken soft coal seams.

关键词： Indirect fracturing Roof of coal seam Fracture propagation and evolution Coalbed methane Cohesive element method Combination weight method

Current Loop Disturbance Suppression for Dual Three Phase Permanent Magnet Synchronous Generators Based on Modified Linear Active Disturbance Rejection Control

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electrical Engineering 2024年第1期10卷 101-113页

作者： Dezhi Xu Hu yao Yang He Wenxiang zhao School of Electrical and Information Engineering Jiangsu UniversityZhenjiang 212013China

A modified four-dimensional linear active disturbance rejection control(LADRC)strategy is proposed for a dual three-phase permanent magnet synchronous generator(DTP-PMSG)system to reduce cross-coupling between the d and q axis currents in the d-q subspace and harmonic currents in the x-y *** the d-q subspace,the proposed strategy uses a model-based LADRC to enhance the decoupling effect between the d and q axes and the disturbance rejection ability against parameter *** the x-y subspace,the 5th and 7th harmonic current suppression abilities are improved by using quasi-resonant units parallel to the extended state observer of the traditional *** proposed modified LADRC strategy improved both the steady-state performance and dynamic response of the DTP-PMSG *** experimental results demonstrate that the proposed strategy is both feasible and effective.

关键词： Dual three-phase permanent magnet synchronous generator current loop decoupling control harmonic suppression linear active disturbance rejection control

Image Inpainting Technique Incorporating Edge Prior and Attention Mechanism

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第1期78卷 999-1025页

作者： Jinxian Bai yao Fan Zhiwei zhao Lizhi Zheng College of Information Engineering Xizang Minzu UniversityXianyang712000China

Recently,deep learning-based image inpainting methods have made great strides in reconstructing damaged ***,these methods often struggle to produce satisfactory results when dealing with missing images with large holes,leading to distortions in the structure and blurring of *** address these problems,we combine the advantages of transformers and convolutions to propose an image inpainting method that incorporates edge priors and attention *** proposed method aims to improve the results of inpainting large holes in images by enhancing the accuracy of structure restoration and the ability to recover texture *** method divides the inpainting task into two phases:edge prediction and image ***,in the edge prediction phase,a transformer architecture is designed to combine axial attention with standard *** design enhances the extraction capability of global structural features and location *** also balances the complexity of self-attention operations,resulting in accurate prediction of the edge structure in the defective *** the image inpainting phase,a multi-scale fusion attention module is *** module makes full use of multi-level distant features and enhances local pixel continuity,thereby significantly improving the quality of image *** evaluate the performance of our *** experiments are conducted on several datasets,including CelebA,Places2,and *** experiments show that our method outperforms the other mainstream ***,it improves Peak Signal-to-Noise Ratio(PSNR)and Structure Similarity Index Measure(SSIM)by 1.141~3.234 db and 0.083~0.235,***,it reduces Learning Perceptual Image Patch Similarity(LPIPS)and Mean Absolute Error(MAE)by 0.0347~0.1753 and 0.0104~0.0402,*** experiments reveal that our method excels at reconstructing images with complete structural information and c

关键词： Image inpainting transformer edge prior axial attention multi-scale fusion attention