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一类tVD型组合差分方法及其在磁流体数值计算中的应用

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空间科学学报 2002年第4期22卷 300-308页

作者：冯学尚范全林魏奉思姚久胜 s.t.wu 中国科学院空间科学与应用研究中心北京100080 CsPAR The University of Alabama in Huntsville USA

根据太阳风数值模拟的特点,考虑到算法的质量（收敛速度、稳定性、精度等）,结合磁流体数值计算的特性,对三维球坐标下磁流体动力学（MHD）方程组中的流体部分采用一种修正Lax-Friedrichs差分法而对磁场部分采用MacCormack格式,发展了... 详细信息

根据太阳风数值模拟的特点,考虑到算法的质量（收敛速度、稳定性、精度等）,结合磁流体数值计算的特性,对三维球坐标下磁流体动力学（MHD）方程组中的流体部分采用一种修正Lax-Friedrichs差分法而对磁场部分采用MacCormack格式,发展了一类快捷的具有tVD特性的组合数值新方法.作为格式的检验,在一维情况下,将其与PPM格式进行了比较,对一维快慢磁流体激波问题得到了与PPM格式精度相同的结果,然后将其应用到定态太阳风的数值模拟上,在不同等离子体β情形下,可得到理想的太阳风定态结构,为今后将此数值模式应用到具有复杂磁场位型或三维真实太阳风暴的数值模拟研究奠定了基础.

关键词：计算 tVD型组合差分格式磁流体数值模拟太阳风

太阳磁场演化和湍动大气中的耀斑能量积累(英文)

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紫金山天文台台刊 1994年第2期13卷 59-69页

作者： C.L.Yin s.t.wu Purple Mountain Observatory the University of Alabama In Huntsville

In this paper we present the results of both evolution of Bibolar Magnetic Regions and flare energy buildup with supergranular diffusion. Based on these results we find (i) MHD processes including diffusion and cyclonic of turbulence play a significant role for the development of the complexities of an active region. the meridional flow controls the poleward migration of magnetic field of the active regions, (ii) the diffusion of photosphere field and the magnitude of the shear speed have important effects on the total energy storage in the solar corona.

关键词：磁场演化能量积累耀斑太阳英文湍动 defines Mathema Regions requires

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平面磁通量压缩流体动力学的数值模拟

爆炸与冲击 1991年第4期11卷 297-308页

作者： L.L.Altgilbers s.t.wu Y.C.Xiao 美国阿拉巴马大学空间等离子体和高层大气物理研究中心和机械工程系 35899

磁压缩发电机(MCGs)是一种应用炸药爆炸压缩导体包围的磁场,从而产生几百兆高斯强磁场并可作为初级能源,产生几百兆焦耳的能量和兆安培的电流。Chernyshev等指出如作为初级能源做某些应用,产生兆安培电流脉冲的上升时间的数量级必须要... 详细信息

磁压缩发电机(MCGs)是一种应用炸药爆炸压缩导体包围的磁场,从而产生几百兆高斯强磁场并可作为初级能源,产生几百兆焦耳的能量和兆安培的电流。Chernyshev等指出如作为初级能源做某些应用,产生兆安培电流脉冲的上升时间的数量级必须要达到微秒量级,但典型的一端燃烧型(end—burn)的磁压缩发电机电流脉冲的上升时间要几百微秒,所以不能满足要求,1978年Pavlovskii等提出应用轴上(axial initiation)起爆的磁压缩发电机,其上升时间可大为缩短。本文为应用数值模拟方法研究一端燃烧型和轴上起爆型两种磁压缩发电机的物理过程。计算模型根据磁流体动力学理论,用二维平面模型,并假设初始磁场均匀分布在等离子体内。假设(x=L)的边界是固定的,在另一边界(x=0)上加压力脉冲.对一端燃烧磁压缩发电机,压力脉冲作用在另一边界的底部,该边界以(?)向上运动。对轴上起爆的磁压缩发电机则压力均匀地加在另一边上,应用理想磁流体动力学方程式组和物态方程 t=(?)p/Rp 式中 D/Dt=(?)/(?)+(?)·▽ ρ,p,t,(?),R和γ相应地为密度,压力,温度,速度,磁感应强度,平均原子量,理想气体常数和比热比,计算时忽略了耗散效应如扩散和热传导等,以及其它外力如重力等。计算程序基本上根据新发展的sINIL格式,用拉氏网格。

关键词：磁通量压缩流体动力学数值模拟

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结构物在sH波作用下的动态偏心距

世界地震工程 1987年第1期 49-55页

作者： s.t.wu E.V.Leyendecker 刘巍赵新平

引言地震时建筑物因扭转效应而导致严重破坏的例子屡见不鲜。因此建筑物结构相应地增加抗扭能力是很必要的。建筑标准或建筑规范中有关扭转效应的现行设计准则主要根据工程判断。这些条款还不很完善。为了避免结构物在地震中倒塌,必须... 详细信息

引言地震时建筑物因扭转效应而导致严重破坏的例子屡见不鲜。因此建筑物结构相应地增加抗扭能力是很必要的。建筑标准或建筑规范中有关扭转效应的现行设计准则主要根据工程判断。这些条款还不很完善。为了避免结构物在地震中倒塌,必须进行这方面的研究——模拟结构物在地震波作用下的实际特性。近来,为了确定平-扭耦联结构系统的动态反应,提出了各种准确的解析模型。例如Kan和Chopra广泛研究了线性与非线性系统质心和刚心间几何偏心的反应效应;Kung和Pecknold根据随机地面

关键词：偏心距剪力长宽比几何偏心结构物 sH

targeting gut microbiota in osteoporosis:impact of the microbial based functional food ingredients

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Food science and Human Wellness 2024年第1期13卷 1-15页

作者： Pauline Duffuler Khushwant s.Bhullar Jianping wu Department of Agricultural Food&Nutritional science University of AlbertaEdmonton T6G 2P5Canada

Osteoporosis is the most common bone disorder,characterized by low bone mineral density and microarchitectural deterioration of the bone tissue,which increases the susceptibility to *** the past decade,emerging research findings reported the implication of gut microbiota on bone health and osteoporosis *** patients or individuals with a lower bone mineral density exhibit an alteration of the gut microbiota at several taxonomic *** reports demonstrate that gut microbiota regulates bone metabolism through the modulation of the gut function(mineral availability and absorption,gut integrity),the immune system,and the endocrine ***,based on the vital role of gut microbiota on bone health,it has emerged as a novel therapeutic target for the prevention of bone loss and the treatment of ***-based functional food ingredients,such as probiotics,prebiotics,synbiotics,and fermented foods,have been developed to alter the gut microbiota composition and function and thus,to provide benefits to the host bone *** promising initial results,microbial-based therapies are still under ***,additional animal studies and clinical trials are needed to understand the interactions between gut microbiota and bone metabolism before further applications.

关键词： Dysbiosis Bone health Probiotic Prebiotic Fermented food synbiotic

sOLAR WIND MODELLING:A NOVEL NUMERICAL sIP-CEsE Model

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SOLAR WIND MODELLING:A NOVEL NUMERICAL SIP-CESE Model

Probing the Bardeen-Kiselev black hole with the cosmological constant caused by Einstein equations coupled with nonlinear electrodynamics using quasinormal modes and greybody bounds

第十二届全国日地空间物理学术讨论会

作者： Xueshang Feng~1 YufenZhou~1 Yanqi Hu~1 s.t.wu~2 (1 state Key Laboratory for space Weather,CssAR,Chinese Academy of science,Beijing 100080) (2 Center for space Plasma and Aeronomic Research,the University of Alabama in Huntsville,Huntsville,AL 35899)

＜正＞Here,we report a new version of the space time Conservative Method（stCM）.In this method,we set numerical discretization by using GAUss’ law,and form a three-dimensional numerical *** wind parameters and their...

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Communications in theoretical Physics 2024年第6期76卷 102-119页

作者： s R wu B Q Wang Z W Long College of Physics Guizhou UniversityGuiyang 550025China College Pharmacy Guizhou University of Traditional Chinese MedicineGuiyang 550025China

In this work,we investigate a static and spherically symmetric Bardeen-Kiselev black hole(BH)with the cosmological constant,which is a solution of the Einstein-non-linear Maxwell field *** compute the quasinormal frequencies for the Bardeen-Kiselev BH with the cosmological constant due to electromagnetic and gravitational *** varying the BH parameters,we discuss the behavior of both real and imaginary parts of the BH quasinormal frequencies and compare these frequencies with the Reissner-Nordström-de sitter BH surrounded by quintessence(RN-dsQ).Interestingly,it is shown that the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dsQ under electromagnetic perturbations are different when the charge parameter q,the state parameter w and the normalization factor c are varied;however,for the gravitational perturbations,the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dsQ are different only when the charge parameter q is ***,compared with the gravitational perturbations,the electromagnetic perturbations can be used to understand nonlinear and linear electromagnetic fields in curved spacetime *** interesting observation is that,due to the presence of Kiselev quintessence,the electromagnetic perturbations around the Bardeen-Kiselev BH with the cosmological constant damps faster and oscillates slowly;for the gravitational perturbations,the quasinormal mode decays slowly and oscillates *** also study the reflection and transmission coefficients along with the absorption cross section in the Bardeen-Kiselev BH with the cosmological constant;it is shown that the transmission coefficients will increase due to the presence of Kiselev quintessence.

关键词： quasinormal modes greybody factors Bardeen-Kiselev black hole with cosmological constant

Weighted Probability Density Estimator with Updated Bandwidths

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Journal of systems science & Complexity 2024年第2期37卷 886-906页

作者： wu Yi YU Wei WANG Xuejun PRAKAsA RAO B L s school of Big Data and Artificial Intelligence Chizhou UniversityChizhou 247000China school of Big Data and statistics Anhui UniversityHefei 230601China CR Rao Advanced Institute of Mathematics Statistics and Computer ScienceHyderabad 500046India

In this paper,the authors study a class of weighted version of probability density *** is shown that the weighted estimator contains some existing estimators of probability density,no matter they are recursive or *** statistical results including weak consistency,strong consistency,rate of strong consistency,and asymptotic normality are established under some mild ***,the random weighted estimator is also *** numerical simulations and a real data analysis are presented to study the numerical performances of the estimators.

关键词： Asymptotic normality consistency numerical simulation probability density real data analysis updated bandwidths weighted estimator

two-dimensional atomically thin Pt layers on MXenes: the role of electronic effects during catalytic dehydrogenation of ethane and propane

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Nano Research 2024年第3期17卷 1251-1258页

作者： Zhe Li tobias K.Misicko Fan Yang Xiaopeng Liu Zhenwei wu Xiaoyang Gao tao Ma Jeffrey t.Miller Daniela s.Mainardi Collin D.Wick Zhenhua Zeng Yang Xiao Yue wu Department of Chemical and Biological Engineering Iowa State University618 Bissell RoadAmesIA 50011USA Institute for Micromanufacturing Louisiana Tech University505 Tech DriveRustonLA 71272USA Davidson school of Chemical Engineering Purdue University480 Stadium Mall DriveWest LafayetteIN 47907USA Michigan Center for Materials Characterization University of Michigan2800 Plymouth RdAnn Arbor MI 48109USA College of Engineering and science Louisiana Tech UniversityRustonLA 71272USA

Atomically thin Pt nanolayers were synthesized on the surface of Mo2tiC2 MXenes and used for the catalytic dehydrogenation of ethane and propane into ethylene and propylene,two important chemicals for the petrochemical *** compared with Pt nanoparticles,the atomically thin Pt nanolayer catalyst showed superior coke-resistance(no deactivation for 24 h),high activity(turnover frequencies(tOFs)of 0.4–1.2 s^(-1)),and selectivity(>95%)toward ethylene and *** unique Pt nanolayer has a similar geometric surface to Pt nanoparticles,enabling the investigations of the electronic effect on the catalytic performance,where the geometric effect is *** is found that the electronic effect plays a critical role in dehydrogenative product selectivity and catalyst *** metal–support interaction is found dependent on the substrate and metal components,providing wide opportunities to explore high-performance MXene-supported metallic catalysts.

关键词： MXene catalysis alkane dehydrogenation nanolayers