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Extension of the High-Order Space-Time Discontinuous Galerkin Cell Vertex Scheme to Solve Time Dependent Diffusion Equations

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Communications in Computational Physics 2012年第5期11卷 1503-1524页

作者： shuangzhang tu Gordon W.Skelton Qing Pang Department of Computer Engineering Jackson State UniversityJacksonMS 39217USA

In this paper,the high-order space-time discontinuous Galerkin cell vertex scheme(DG-CVS)developed by the authors for hyperbolic conservation laws is extended for time dependent diffusion *** the extension,the treatment of the diffusive flux is exactly the same as that for the advective *** to the Riemannsolver-free and reconstruction-free features of DG-CVS,both the advective flux and the diffusive flux are evaluated using continuous information across the cell *** a result,the resulting formulation with diffusive fluxes present is still consistent and does not need any extra ad hoc techniques to cure the common“variational crime”problem when traditional DG methods are applied to diffusion *** this reason,DG-CVS is conceptually simpler than other existing DG-typed *** numerical tests demonstrate that the convergence order based on the L_(2)-norm is optimal,i.e.O(h^(p+1))for the solution and O(h^(p))for the solution gradients,when the basis polynomials are of odd *** even-degree polynomials,the convergence order is sub-optimal for the solution and optimal for the solution *** same odd-even behaviour can also be seen in some other DG-typed methods.

关键词： High-order method space-time method discontinuous Galerkin(DG)method cellvertex scheme(CVS) diffusion equations

A Compact High Order Space-Time Method for Conservation Laws

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Communications in Computational Physics 2011年第2期9卷 441-480页

作者： shuangzhang tu Gordon W.Skelton Qing Pang Department of Computer Engineering Jackson State UniversityJacksonMS 39217USA

This paper presents a novel high-order space-time method for hyperbolic conservation *** important concepts,the staggered space-time mesh of the space-time conservation element/solution element(CE/SE)method and the local discontinuous basis functions of the space-time discontinuous Galerkin(DG)finite element method,are the two key ingredients of the new *** staggered spacetime mesh is constructed using the cell-vertex structure of the underlying spatial *** universal definitions of CEs and SEs are independent of the underlying spatial mesh and thus suitable for arbitrarily unstructured *** solution within each physical time step is updated alternately at the cell level and the vertex *** this solution updating strategy and the DG ingredient,the new scheme here is termed as the discontinuous Galerkin cell-vertex scheme(DG-CVS).The high order of accuracy is achieved by employing high-order Taylor polynomials as the basis functions inside each *** present DG-CVS exhibits many advantageous features such as Riemann-solver-free,high-order accuracy,point-implicitness,compactness,and ease of handling boundary *** numerical tests including the scalar advection equations and compressible Euler equations will demonstrate the performance of the new method.

关键词： High order method space-time method cell-vertex scheme(CVS) conservation laws

Increased excitatory amino acid transporter 2 levels in basolateral amygdala astrocytes mediate chronic stress–induced anxiety-like behavior

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Neural Regeneration Research 2025年第6期20卷 1721-1734页

作者： Xirong Xu Shoumin Xuan Shuai Chen Dan Liu Qian Xiao Jie tu Shenzhen Key Laboratory of Neuroimmunomodulation for Neurological Diseases Shenzhen-Hong Kong Institute of Brain ScienceShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina CAS Key Laboratory of Brain Connectome and Manipulation Brain Cognition and Brain Disease Institute(BCBDI)Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina Guangdong Provincial Key Laboratory of Brain Connectome and Behavior the Brain Cognition and Brain Disease Institute(BCBDI)Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina University of Chinese of Academy of Sciences BeijingChina Faculty of Life and Health Sciences Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina

The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with ***, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1D promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal *** knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was ob

关键词： anxiety astrocytes basolateral amygdala behavior dihydrokainic acid excitatory amino acid transporter 2 fiber photometry glutamate LDN-212320 transporter

Extramedullary plasmacytoma with the uvula as first affected site:A case report

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World Journal of Clinical Oncology 2025年第1期16卷 53-58页

作者： Jing Yang Hui Peng Sheng-Ke tu Min Li Kui Song Department of Hematology The First Affiliated Hospital of Jishou UniversityJishou 416000Hunan ProvinceChina Department of Pharmacy The First Affiliated Hospital of Jishou UniversityJishou 416000Hunan ProvinceChina

BACKGROUND Extramedullary plasmacytoma(EMP)represents one of the rarer forms of plasma cell malignancies,capable of impacting a variety of tissues and organs throughout the *** majority of EMP cases are predominantly found in the head and neck region,especially within the laryngopharynx,as well as in the gastrointestinal *** there have been documented instances of oropharyngeal involvement in EMP cases in the academic literature,it is important to note that EMP specifically affecting the uvula is exceedingly ***,it is noteworthy that over 60% of epithelial carcinomas in the upper respiratory tract and oropharynx tend to metastasize to the cervical lymph nodes,indicating a propensity for regional spread in these types of *** this context,we present a rare case of extramedullary plasmacytoma where the uvula served as the initially affected *** case emphasizes the need for heightened awareness among clinicians regarding such unusual comorbidities,as early recognition and diagnosis can significantly influence patient management and treatment *** addition,a review of the relevant literature is included to further educate and inform healthcare professionals about this rare presentation,ultimately aiming to enhance clinical understanding and improve patient care in similar *** SUMMARY A 51-year-old man was admitted to our hospital because of a slowly enlarging neck mass.A physical examination revealed a palpable left lymph node,and magnetic resonance imaging(MRI)of the oropharynx and the neck showed a soft tissue mass in the oropharynx and enlargement of multiple lymph nodes in the *** soft tissue mass was diagnosed as plasmacytoma by immunohistochemical *** immunoglobulins and bone marrow biopsy showed normal ***,we diagnosed that as EMP of the *** four cycles of adjuvant chemotherapy dominated by bortezomib,MRI reexamination showed a significant reduction of the mass

关键词： Extramedullary plasmacytoma Plasmacytoma Uvula Multiple myeloma Case report

De novo synthesis of atropisomeric benzofurans via Cu/SPDO complex catalyzed asymmetric formal [3 + 2] annulation

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Science China Chemistry 2025年第01期 174-180页

作者： Fan-Xiao Meng Xing-Yu Wang Ka Lu Ju-Song Yang Fu-Min Zhang Ai-Jun Ma Bao Du Yong-Qiang tu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering Lanzhou University School of Chemistry and Chemical Engineering Shanghai Jiao Tong University School of Biotechnology and Health Sciences Wuyi University

Herein, the de novo synthesis of atropisomeric benzofurans through the Cu/spirocyclic-pyrrolidine-oxazoline(SPDO) complex catalyze asymmetric formal [3 + 2] cycloaddition between quinones and ynamides is explored, producing a range of structurally diverse axially chiral benzofurans in satisfactory yields with good to excellent enantioselectivities. Furthermore, density functional theory calculations were applied to explain the possible reaction mechanism.

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柳江盆地髫髻山组凝灰岩地球化学与熔体包裹体水含量特征

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岩矿测试 2025年第1期44卷 88-101页

作者：赵汇珍陈勇涂聪冯艳伟中国石油大学(华东)深层油气全国重点实验室山东青岛266580 中国石油大学(华东)地球科学与技术学院山东青岛266580 中国科学技术大学地球和空间科学学院安徽合肥230026

水作为岩浆体系中最主要的挥发组分,对岩浆的形成和演化有重要的影响,柳江盆地髫髻山组岩浆岩是燕山期火山活动的重要产物,尽管前人对其地球化学特征进行了大量研究,但关于柳江盆地燕山期岩浆中的水含量仍不清楚。熔体包裹体记录了原始... 详细信息

水作为岩浆体系中最主要的挥发组分,对岩浆的形成和演化有重要的影响,柳江盆地髫髻山组岩浆岩是燕山期火山活动的重要产物,尽管前人对其地球化学特征进行了大量研究,但关于柳江盆地燕山期岩浆中的水含量仍不清楚。熔体包裹体记录了原始岩浆信息,是获取岩浆水含量特征的最直接样品。本文基于全岩地球化学分析,利用标准样品建立了显微激光拉曼光谱定量熔体包裹体水含量的标定曲线,并对柳江盆地髫髻山组下部流纹质岩屑-晶屑凝灰岩中石英斑晶内的原生熔体包裹体进行了水含量定量分析。结果表明:髫髻山组下部凝灰岩样品具有富Si、Al、大离子亲石元素富集、高场强元素亏损、轻稀土富集、重稀土亏损、负Eu异常、Sr含量低等特点;熔体包裹体中水含量的定量分析结果为0.99%~4.98%,平均水含量为2.62%,与前人统计的酸性岩浆水含量基本一致。地球化学特征和熔体包裹体水含量分析结果共同揭示了研究区髫髻山期早期为富水酸性岩浆。结合髫髻山期样品的熔体包裹体水含量测定结果及其早期的大规模火山喷发背景,本文认为岩浆中高含水量增强了岩浆系统的喷发动力,是诱发研究区髫髻山期早期大规模火山爆发的有利因素之一。

关键词：柳江盆地髫髻山组凝灰岩熔体包裹体水含量显微激光拉曼光谱法

Mechanisms of support failure and prevention measures under double-layer room mining gobs——A case study: Shigetai coal mine

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International Journal of Mining Science and Technology 2019年第6期29卷 955-962页

作者： Defu Zhu Shihao tu Hongsheng tu Zhenqian Yang State Key Laboratory of Deep Coal Resource China University of Mining and Technology

In the practice of mining shallow buried ultra-close seams,support failure tends to occur during the process of longwall undermining beneath two layers of room mining goaf(TLRMG).In this paper,the factors causing support failure are summarized into geology and mining *** column lithology and composite beam theory,the key stratum of the rock strata is determined.A finite element numerical simulation is used to analyze the overlying load distribution rule of the main roof for different plane positions of the upper and lower room mining *** tributary area theory(TAT)is adopted to analyze the vertical load distribution of each pillar,and dynamic models of coal pillar instability and main roof fracture are *** key block instability analysis,two critical moments are established,of which critical moment A has the greater dynamic load *** economic losses and safety hazards are created by the dynamic load of the fracturing of the main *** reduce these negative effects,a method of pulling out supports is developed and two alternative measures for support failure prevention are proposed:reinforcing stope supports in conjunction with reducing mining height,or drilling ground holes to pre-split the main *** on a comprehensive consideration of economic factors and the two categories of support failure causes,the method of reinforcing stope supports while reducing mining height was selected for use on the mining site.

关键词： Multiple room mining goaf Mechanism of supports failure Numerical simulation Prevention measure

Creep behavior of plasma sprayed NiCr and NiCrAl coating-based systems

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Acta Metallurgica Sinica(English Letters) 2011年第3期24卷 183-189页

作者： Shan-tung tu Key Laboratory of Safety Science of Pressurized System Ministry of EducationEast China University of Science and Technology

The creep behavior of the plasma sprayed NiCr and NiCrA1 coating/Nickel alloy 690 substrate systems at 1033 K was investigated. Results showed that there was almost no difference in the creep lives between the NiCr and NiCrA1 coated specimens at a given stress level, since the contents of Cr used in the NiCr and NiCrA1 powders are almost same. The relationship between the minimum creep rate and the applied stress followed the well-known Norton＇s power law, εmin=Aσ^n, with the values of A=2.66×10^-16 MPa^-n·h^-1 and n=6.48. The relation between the applied stress and time to rupture of the coated specimens can be estimated by using Larson-Miller equation. The θ projection method can be used to accurately characterize the creep behavior of the coated specimens.

关键词： Creep Coating θ projection method Minimum creep strainrate

Creep crack growth in a Cr-Mo-V type steel: experimental observation and prediction

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Acta Metallurgica Sinica(English Letters) 2011年第2期24卷 81-91页

作者： Shan-tung tu Key Laboratory of Safety Science of Pressurized System Ministry of Education School of Mechanical and Power Engineering East China University of Science and Technology

In this study, the creep crack growth （CCG） properties and fracture mechanism of a Cr-Mo-V steel at 566 C in compact tension （CT） specimens were investigated, and the CCG rate was predicted by using the NSW model. The results show that the CCG rate measured by CT specimens is much lower than that predicted by the NSW model under plane-strain state. This means that the NSW model prediction for the CCG rate of the steel is over-conservative. In addition, the CCG rate da/dt versus C measured by the experiments shows the piecewise linear relation on log-log scale instead of a single linear relation predicted by the NSW model. The main reasons for these results are that the actual creep fracture mechanism of the steel and the actual creep crack tip stress field in the CT specimens have not been fully captured in the NSW model. The experimental observation shows that the creep crack propagates in a discontinuous way （step by step） at meso-scale, and the cracks at micro-scale are usually formed by the growth and coalescence of voids on grain boundaries. The NSW model based on the creep ductility exhaustion approach may not correctly describe this creep fracture process. In addition, the opening stress and triaxial stress ahead of crack tips calculated by three-dimensional finite element method is lower than those predicted by the HRR stress field which is used in the NSW model under plane-strain state. The use of the high HRR stress field will cause high CCG rates. The change in the creep fracture mechanism at micro-scale in different ranges of C may cause the piecewise linear relation between the da/dt and C . Therefore, it is necessary to study the actual CCG mechanism in a wide range of C and the actual creep crack tip stress field to establish accurate CCG prediction models.

关键词： Creep crack growth Prediction NSW model Fracture mechanism Finite element method