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Applied Mathematics and Mechanics(English Edition) 2017年第3期38卷 343-362页

作者： Wei SU zhenyu tang Bijiao HE Guobiao CAI School of Astronautics Beihang University Beijing 100191 China Beijing Institute of Spacecraft Environment Engineering Beijing 100094 China

A stable high-order Runge-Kutta discontinuous Galerkin(RKDG) scheme that strictly preserves positivity of the solution is designed to solve the Boltzmann kinetic equation with model collision integrals. Stability is kept by accuracy of velocity discretization, conservative calculation of the discrete collision relaxation term, and a limiter. By keeping the time step smaller than the local mean collision time and forcing positivity values of velocity distribution functions on certain points, the limiter can preserve positivity of solutions to the cell average velocity distribution functions. Verification is performed with a normal shock wave at a Mach number 2.05, a hypersonic flow about a two-dimensional(2D) cylinder at Mach numbers 6.0 and 12.0, and an unsteady shock tube flow. The results show that, the scheme is stable and accurate to capture shock structures in steady and unsteady hypersonic rarefied gaseous flows. Compared with two widely used limiters, the current limiter has the advantage of easy implementation and ability of minimizing the influence of accuracy of the original RKDG method.

关键词： model equation hypersonic flow discontinuous Galerkin (DG) conservative discretization positivity-preserving limiter Courant-Friedrichs-Lewy (CFL) condition

Analysis and Simulations of Open-Source Intelligence Process System Dynamics from User’s Perspective

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Computer Modeling in Engineering & Sciences 2023年第1期134卷 541-558页

作者： Huan Liu zhenyu tang Ning Zhao Wei Qian Northeast Agricultural University Harbin150030China Harbin Institute of Technology Library Harbin150001China

In today’s society with advanced Internet,the amount of information increases dramatically with each passing day,which leads to increasingly complex processes of open-source ***,it is more important to rationalize the operation mode and improve the operation efficiency of open-source intelligence under the premise of satisfying users’*** paper focuses on the simulation study of the process system of opensource intelligence from the user’s ***,the basic concept and development status of open-source intelligence are introduced in ***,six existing intelligence operation process models are summarized and their advantages and disadvantages are compared in *** on users’preference,the open-source intelligence system simulation theory model is constructed from four aspects:intelligence collection,intelligence processing,intelligence analysis,and intelligence ***,the dynamics model of the open-source intelligence process system is constructed based on the open-source intelligence system simulation theoretical model,which specifically includes five parts:determination of system boundary,construction of causal loop diagram,construction of stock flow diagram,writing ofmathematical equations,and system sensitivity ***,the system simulation results were *** was found that improving the system of intelligence agencies,opening up government affairs,improving the professional level of intelligence personnel,strengthening the communication and cooperation among personnel of various intelligence departments,and expressing intelligence products through diverse forms can effectively improve the operational efficiency of the open-source intelligence process system.

关键词： Open-source intelligence system dynamics feedback user demand deviation

Experimental and numerical analysis of the heat flux characteristic of the plume of a 120-N thruster

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Science China(Technological Sciences) 2019年第10期62卷 1854-1860页

作者： ZHANG MingXing CAI GuoBiao HE BiJiao tang zhenyu ZHOU Hao Beijing Institute of Space Long March Vehicle Beijing100076China School of Astronautics Beihang UniversityBeijing100191China Beijing Institute of Spacecraft Environment Engineering Beijing100094China

The convective heat transfer of the plume of a 120-N thruster is investigated experimentally and numerically. Numerical results agree well with experimental results in that there is a nonlinear decrease in convective heat transfer with an increasing cone angle. It is also found that convective heat transfer decreases with increasing distance from the thruster outlet. Furthermore, the convective heat transfer of the plume mainly concentrates within a 35° cone angle and the heat flux decreases to the same order as solar radiation at the Earth’s surface when the cone angle exceeds 60°. The results of the study will help improve spacecraft design.

关键词： vacuum plume heat flux computational fluid dynamics/direct simulation Monte Carlo method shock wave

Cyclic Autoencoder for Multimodal Data Alignment Using Custom Datasets

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Computer Systems Science & Engineering 2021年第10期39卷 37-54页

作者： zhenyu tang Jin Liu Chao Yu Y.Ken Wang College of Information Engineering Shanghai Maritime UniversityShanghai200135China Division of Management and Education University of PittsburghBradford16701USA

The subtitle recognition under multimodal data fusion in this paper aims to recognize text lines from image and audio *** existing multimodal fusion methods tend to be associated with pre-fusion as well as post-fusion,which is not reasonable and difficult to *** believe that fusing images and audio before the decision layer,i.e.,intermediate fusion,to take advantage of the complementary multimodal data,will benefit text line *** this end,we propose:(i)a novel cyclic autoencoder based on convolutional neural *** feature dimensions of the two modal data are aligned under the premise of stabilizing the compressed image features,thus the high-dimensional features of different modal data are fused at the shallow level of the model.(ii)A residual attention mechanism that helps us improve the performance of the *** of interest in the image are enhanced and regions of disinterest are weakened,thus we can extract the features of the text regions without further increasing the depth of the model(iii)a fully convolutional network for video subtitle *** choose DenseNet-121 as the backbone network for feature extraction,which effectively enabling the recognition of video subtitles in complex *** experiments are performed on our custom datasets,and the automatic and manual evaluation results show that our method reaches the state-of-the-art.

关键词： Deep learning convolutional neural network multimodal text recognition

Neuroprotective role of edaravone and the effects of endoplasmic reticulum stress in an adult rat model of focal cerebral ischemia/reperfusion

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Neural Regeneration Research 2010年第3期5卷 197-204页

作者： Xiangmin Shen Liming Tan Yunhai Liu Hainan Zhang Chunyu Wang Qidong Yang QingHuang Lin Zhou zhenyu tang Department of Neurology Xiangya Hospital Central South University Changsha 410008 Hunan Province China Department of Neurology Second Xiangya Hospital Central South University Changsha 410011 Hunan Province China

BACKGROUND： Endoplasmic reticulum （ER） stress impairs ER functions and leads to the accumulation of unfolded or misfolded proteins in the ER lumen. ER stress-induced cell death plays an important role in cerebral ischemia. Edaravon （3-methyl-1-phenyl-2-pyrazolin-5-one） is a potent and novel scavenger of free radicals that inhibit delayed neuronal death, as demonstrated by in vitro and animal studies. However, its effect on ER stress and induced neuronal apoptosis in a rat model of brief middle cerebral artery occlusion remains unclear. OBJECTIVE： To explore the effects of edaravone on the expression of ER stress-related factors and neuronal apoptosis, based on the hypothesis that edaravone influences ER stress in a rat model of cerebral ischemia/reperfusion. DESIGN, TIME AND SETTING： A randomized, controlled, animal study was performed at the Laboratory of Department of Neurology, Xiangya Hospital and the Department of Laboratory Animals, Xiangya Medical College, Central South University in China from June 2005 to May 2006. MATERIALS： Edaravone was purchased from Simcere Pharmaceutical Group, China. METHODS： A total of 216 adult, male, Sprague Dawley rats were randomly assigned to sham-surgery, model and edaravone groups, with 72 rats in each group, Brief middle cerebral artery occlusion was established in the model and edaravone groups. In addition, the edaravone group rats were injected with 3 mg/kg edaravone through the tail vein. MAIN OUTCOME MEASURES： RNA-dependent protein kinase-like endoplasmic reticulum eukaryotic translation initiation factor 2a kinase （PERK） and C/EBP homology protein （CHOP） mRNA expression in the ischemic parietal cortex was determined by reverse transcriptionpolymerase chain reaction; phosphorylated PERK and CHOP protein expression was detected by immunohistochemistry; neuronal apoptosis was detected by TdT-mediated-dUTP nick end labeling. RESULTS： Neurological deficit scores were significantly reduced in the edaravone group compared to

关键词： edaravone cerebral ischemia/reperfusion endoplasmic reticulum stress RNA-dependent protein kinase-like endoplasmic reticulum elF2a kinase C/EBP homology protein brain injury neural regeneration

两种用于NS-DSMC耦合方法的连续失效参数对比

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北京航空航天大学学报 2014年第3期40卷 389-393页

作者：唐振宇蔡国飙北京航空航天大学宇航学院北京100191

NS-DSMC(Navier Stokes-Direct Simulation Monte Carlo)耦合方法是计算连续-稀薄跨流域流动的主要方法,应用过程中如何确定连续流域和稀薄流域的界面是此方法的关键问题之一,界面位置通常通过连续失效参数来判定.为合理选择连续失效参... 详细信息

NS-DSMC(Navier Stokes-Direct Simulation Monte Carlo)耦合方法是计算连续-稀薄跨流域流动的主要方法,应用过程中如何确定连续流域和稀薄流域的界面是此方法的关键问题之一,界面位置通常通过连续失效参数来判定.为合理选择连续失效参数,对目前广泛使用的两种连续失效参数KnQ和B参数进行了理论上的分析和比较,表明虽然他们建立的出发点不同,但在数学形式上具有一定相似性.通过圆柱绕流问题的数值试验进一步验证了两种连续失效参数具有一定对应关系.KnQ和B两种连续失效参数在NS-DSMC耦合方法中应用效果相差不大,但KnQ的阈值0.05适用范围较广,而B参数的阈值对不同流动问题会有变化.

关键词：直接模拟蒙特卡罗 NS—DSMC耦合方法连续失效参数 Chapman-Enskog 速度分布函数

CYP46A1 intron-2 T/C polymorphism and Alzheimer's disease:an updated meta-analysis of 16 studies including 3960 cases and 3828 controls

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CYP46A1 intron-2 T/C polymorphism and Alzheimer's disease:an...

区域创新中高校图书馆科技资源整合共享的对策研究

中华医学会第十七次全国神经病学学术会议

作者： Min Li Wei Wang zhenyu tang Department of Neurology The Second Affiliated HospitalSchool of MedicineNanchang University

Whether the variations in the cholesterol24S-hydroxylase(CYP46A1)gene would raise Alzheimer’s risk is still undetermined,A previous meta-analysis about the association between AD susceptibility and CYP46A1 intron-2 TIC(rs754203)has led to inconsistent *** assess the relationship between the CYP46A1 rs754203polymorphism and AD risk more exactly,relevant

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科技管理研究 2008年第9期28卷 53-56页

作者：唐振宇哈尔滨工业大学图书馆黑龙江哈尔滨150001

高校图书馆在区域创新中发挥着重要的作用。文章阐述了区域创新条件下高校文献信息资源整合的重要意义,分析了高校图书馆对区域创新的影响、区域创新对高校图书馆及其科技文献的要求、区域创新中文献整合方面高校图书馆存在的问题和面... 详细信息

高校图书馆在区域创新中发挥着重要的作用。文章阐述了区域创新条件下高校文献信息资源整合的重要意义,分析了高校图书馆对区域创新的影响、区域创新对高校图书馆及其科技文献的要求、区域创新中文献整合方面高校图书馆存在的问题和面临的挑战。在理论分析与调查数据统计的基础上,提出了区域创新中高校图书馆实现科技资源整合共享的策略与途径。

关键词：高校图书馆区域创新资源整合资源共享

Mutations in the HFE Gene and Sporadic Amyotrophic Lateral Sclerosis Risk:A Meta-Analysis of Observational Studies

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Mutations in the HFE Gene and Sporadic Amyotrophic Lateral S...

Hyperuricemia and risk of stroke:a systematic review and meta-analysis of prospective studies

中华医学会第十七次全国神经病学学术会议

作者： Min Li Lei Wang Wei Wang Xueliang Qi zhenyu tang Department of Neurology The Second Affiliated HospitalSchool of MedicineNanchang University

Background Iron homeostasis dysregulation has been regarded as an important mechanism in neurodegenerative *** H63D and C282Y polymorphisms in the HFE gene may be involved in the development of sporadic amyotrophic la...

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Hyperuricemia and risk of stroke:a systematic review and met...