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High order moment closure for Vlasov-Maxwell equations

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Frontiers of Mathematics in China 2015年第5期10卷 1087-1100页

作者： Yana DI Zhenzhong kou Ruo LI The State Key Laboratory of Scientific and Engineering Computing Chinese Academy of Sciences Beijing 100190 China National Center for Mathematics and Interdisciplinary Sciences Chinese Academy of Sciences Beijing 100190 China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190 China HEDPS & CAPT LMAM & School of Mathematical Sciences Peking University Beijing 100871 China

The extended magnetohydrodynamic models are derived based on the moment closure of the Vlasov-Maxwell （VM） equations. We adopt the Grad type moment expansion which was firstly proposed for the Boltzmann equation. A new regularization method for the Grad＇s moment system was recently proposed to achieve the globally hyperbolicity so that the local well-posedness of the moment system is attained. For the VM equations, the moment expansion of the convection term is exactly the same as that in the Boltzmann equation, thus the new developed regularization applies. The moment expansion of the electromagnetic force term in the VM equations turns out to be a linear source term, which can preserve the conservative properties of the distribution function in the VM equations perfectly.

关键词： Moment closure Vlasov-Maxwell (VM) equations Boltzmannequation extended magnetohydrodynamics

10k‐level integrated rice database shows power for exploiting rare variants^(FA)

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Journal of Integrative Plant Biology 2023年第12期65卷 2539-2540页

作者： Hong Yu Liquan kou Jiayang Li State Key Laboratory of Plant Genomics National Center for Plant Gene ResearchInstitute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Yazhouwan National Laboratory Sanya 572024China

Rice is one of the most important staple crops,feeding half of the world's *** the 1990s,rice became a model plant to study monocots due to its relatively small genome and efficient transformation system(Izawa and Shimamoto,1996).Rice is the first crop with a sequenced and assembled reference genome(Wang and Han,2022),and rice genes have been cloned via the map‐based cloning system,showing that key regulators in rice play critical roles in determining important agronomic traits(Guo et al.,2018;Chen et al.,2022).

关键词： crops population agronomic

A dynamic-mode-decomposition-based acceleration method for unsteady adjoint equations at low Reynolds numbers

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Theoretical & Applied Mechanics Letters 2023年第5期13卷 353-356页

作者： Wengang Chen Jiaqing kou Wenkai Yang Changzhou Institute of Technology Changzhou 213032China Institute of Aerodynamics RWTH Aachen UniversityWüllnerstraße 5a52062 AachenGermany

The computational cost of unsteady adjoint equations remains high in adjoint-based unsteady aerodynamic *** this letter,the solution of unsteady adjoint equations is accelerated by dynamic mode decomposi-tion(DMD).The pseudo-time marching of every real-time step is approximated as an infinite-dimensional linear dynamical ***,DMD is utilized to analyze the adjoint vectors sampled from these pseudo-time ***-order zero frequency mode is selected to accelerate the pseudo-time marching of unsteady adjoint equations in every real-time *** flow past a stationary circular cylinder and an unsteady aerodynamic shape optimization example,the efficiency of solving unsteady adjoint equations is significantly ***-sults show that one hundred adjoint vectors contains enough information about the pseudo-time dynamics,and the adjoint dominant mode can be precisely predicted only by five snapshots produced from the adjoint vectors,which indicates DMD analysis for pseudo-time marching of unsteady adjoint equations is efficient.

关键词： Acceleration method Unsteady adjoint Dynamic mode decomposition Optimization efficiency

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兽用抗菌复方制剂研究进展

中国兽医杂志 2025年第1期61卷 106-114页

作者：王茹寇紫艳田校源黄玲利华中农业大学动物医学院国家兽药残留基准实验室湖北武汉430070 国家兽药安全评价实验室湖北武汉430070 农业农村部兽药残留检测重点实验室湖北武汉430070

随着动物感染性疾病的复杂化和细菌耐药性的发展,兽医临床急需对混合感染和耐药菌有效的新型抗菌药物,但新药开发难度大、费用高、周期长。抗菌药联合使用既可以增加抗菌谱,又可以防止耐药性出现,在疾病治疗中起着重要的作用。复方制剂... 详细信息

随着动物感染性疾病的复杂化和细菌耐药性的发展,兽医临床急需对混合感染和耐药菌有效的新型抗菌药物,但新药开发难度大、费用高、周期长。抗菌药联合使用既可以增加抗菌谱,又可以防止耐药性出现,在疾病治疗中起着重要的作用。复方制剂是抗菌药联合使用的简易形式,因此兽用复方制剂研制具有广阔发展空间。本文总结了兽用抗菌复方制剂研发、批准和使用情况的研究进展,提出了兽用抗菌复方制剂研发中存在的主要问题,为今后相关的科学研究和产品研发提供了一定的参考。

关键词：兽药复方制剂抗菌药联合用药

Genetic Algorithms for Auto-Clustering in KDD

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Journal of Systems Engineering and Electronics 2000年第3期11卷 53-58页

作者： Li, Minqiang Li, Jianwu kou, Jisong Tianjin Univ Tianjin China

In solving the clustering problem in the context of knowledge discovery in databases (KDD), the traditional methods, for example, the K-means algorithm and its variants, usually require the users to provide the number of clusters in advance based on the pro-information. Unfortunately, the number of clusters in general is unknown to the users who are usually short of pro-information. Therefore, the clustering calculation becomes a tedious trial-and-error work, and the result is often not global optimal especially when the number of clusters is large. In this paper, a new dynamic clustering method based on genetic algorithms (GA) is proposed and applied for auto-clustering of data entities in large databases. The algorithm can automatically cluster the data according to their similarities and find the exact number of clusters. Experiment results indicate that the method is of global optimization by dynamically clustering logic.

关键词： Data reduction Database systems Error analysis Optimization

Rank-One Cross Commutators on Backward Shift Invariant Subspaces on the Bidisk

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Acta Mathematica Sinica,English Series 2009年第5期25卷 693-714页

作者： Kei Ji IZUCHI kou Hei IZUCHI Department of Mathematics Niigata University Graduate School of Science and Technology Niigata University Department of Mathematics Graduate School of ScienceHokkaido University

For a backward shift invariant subspace N in H^2（Г^2）, the operators Sz and Sw on N are defined by Sz = PNTz｜N and Sw, = PNTw｜N, where PN is the orthogonal projection from L^2（Г^2） onto N. We give a characteri... 详细信息

关键词： backward shift invariant subspace invariant subspace Hardy space cross commutator rank-one operator

Detection approach for unusable shared bikes enabled by reinforcement learning and PageRank algorithm

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Journal of Safety Science and Resilience 2023年第2期4卷 220-227页

作者： Yu Zhou Ran Zheng Gang kou Colege of Economics and Management Inner Mongolia UniversityHohhot 010021China School of Business Administration Southwestern University of Finance and EconomicsChengdu 611130China

Existing research models can neither indicate the availability of shared bikes nor detect unusable ones owing to a lack of information on bike maintenance and *** improve awareness regarding the availability of shared bikes,we propose an innovative approach for detecting unusable shared bikes based on reinforcement learning and the PageRank *** proposed method identifies unusable shared bikes depending on the local travel data and provides a ranking of the shared bikes according to their availability *** a sliding time window,the value function for the reinforcement learning model was determined by considering the cumulative number of unavailable shared bikes,the proportion of rental cancelations at the same stations,and the mean time between the *** learning was then used to identify shared bikes with the worst *** availability ranking for the shared bikes below the reward threshold was performed using the PageRank *** proposed detection approach was applied to a trip dataset of a real-world bike-sharing system to illustrate the modeling process and its *** detection results of unusable shared bikes in the absence of failure and feedback data can provide essential information to support the maintenance management decisions regarding shared bikes.

关键词： Bike-sharing system Bike availability Maintenance Failure Shared bike Intelligent transportation Reinforcement learning PageRank algorithm Detection

Click chemistry approach to functionalize two-dimensional macromolecules of graphene oxide nanosheets

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Nano-Micro Letters 2010年第3期2卷 177-183页

作者： Liang kou Hongkun He Chao Gao MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Zhejiang University

A facile "click chemistry" approach to functionalize 2D macromolecules of graphene oxide nanosheets with poly(ethylene glycol) of different molecular weights,polystyrene,palmitic acid and various amino acids was ***,TGA,Raman spectroscopy,XPS,XRD,TEM,AFM and SEM were utilized to characterize the *** degree of functionalization was achieved on the flat surfaces of graphene oxide,affording polymer-grafted 2D brushes and amino acids-immobilized nanosheets,which show improved solubility in organic *** click chemistry strategy reported herein provides a facile and general method for functionalization of graphene oxide with macromolecules and desired biomolecules.

关键词： Graphene Click chemistry Chemical modification PEG Amino acids

Diffuse axonal injury after traumatic cerebral microbleeds: an evaluation of imaging techniques

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Neural Regeneration Research 2014年第12期9卷 1222-1230页

作者： Jun Liu Zhifeng kou Yongquan Tian Department of Radiology Second Xiangya Hospital Central South University Department of Biomedical Engineering and Radiology School of Medicine Wayne State University School of Public Administration Central South University

Previous neuropathological studies regarding traumatic brain injury have primarily focused on changes in large structures, for example, the clinical prognosis after cerebral contusion, intrace- rebral hematoma, and epidural and subdural hematoma. In fact, many smaller injuries can also lead to severe neurological disorders. For example, cerebral microbleeds result in the dysfunc- tion of adjacent neurons and the disassociation between cortex and subcortical structures. These tiny changes cannot be adequately visualized on CT or conventional MRI. In contrast, gradient echo sequence-based susceptibility-weighted imaging is very sensitive to blood metabolites and microbleeds, and can be used to evaluate traumatic cerebral microbleeds with high sensitivity and accuracy. Cerebral microbleed can be considered as an important imaging marker for dif- fuse axonal injury with potential relevance for prognosis. For this reason, based on experimental and clinical studies, this study reviews the role of imaging data showing traumatic cerebral microbleeds in the evaluation of cerebral neuronal injury and neurofunctional loss.

关键词： nerve regeneration neuroimaging traumatic brain injury cerebral microbleeds diffuse axonal injury gradient-recalled-echo susceptibility weighted imaging review neural regeneration