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Vanishing theorems for f-CC harmonic maps with potential H into sub-Riemannian manifolds
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作者 LI Jing HE Guo-qing ZHAO Pei-biao 《Applied Mathematics(A Journal of Chinese Universities)》 2025年第4期802-817,共16页
In this paper,we introduce the notion of f-CC harmonic maps with potential H from a Riemannian manifold into sub-Riemannian manifolds,and achieve some vanishing theorems for f-CC harmonic maps with potential H via the... In this paper,we introduce the notion of f-CC harmonic maps with potential H from a Riemannian manifold into sub-Riemannian manifolds,and achieve some vanishing theorems for f-CC harmonic maps with potential H via the stress-energy tensor and the monotonicity formulas. 展开更多
关键词 f-CC harmonic map with potential stress energy tensor sub-riemannian manifold
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RESEARCH ANNOUNCEMENTS ON "UPPER BOUND ESTIMATES OF EIGENVALUES FOR HORMANDER OPERATORS ON NON-EQUIREGULAR SUB-RIEMANNIAN MANIFOLDS"
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作者 CHEN Hua CHEN Hong-ge LI Jin-ning 《数学杂志》 2022年第1期1-5,共5页
1 Introduction and Main Results For n≥2,let M be a n-dimensional connected smooth manifold.We take a fixed smooth measure on M with strictly positive density,and write dx as the measure when we integrate.Also,we simp... 1 Introduction and Main Results For n≥2,let M be a n-dimensional connected smooth manifold.We take a fixed smooth measure on M with strictly positive density,and write dx as the measure when we integrate.Also,we simply denote the measure of a set E?M by|E|. 展开更多
关键词 manifold. simply STRICTLY
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Federated Multi-Label Feature Selection via Dual-Layer Hybrid Breeding Cooperative Particle Swarm Optimization with Manifold and Sparsity Regularization
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作者 Songsong Zhang Huazhong Jin +5 位作者 Zhiwei Ye Jia Yang Jixin Zhang Dongfang Wu Xiao Zheng Dingfeng Song 《Computers, Materials & Continua》 2026年第1期1141-1159,共19页
Multi-label feature selection(MFS)is a crucial dimensionality reduction technique aimed at identifying informative features associated with multiple labels.However,traditional centralized methods face significant chal... Multi-label feature selection(MFS)is a crucial dimensionality reduction technique aimed at identifying informative features associated with multiple labels.However,traditional centralized methods face significant challenges in privacy-sensitive and distributed settings,often neglecting label dependencies and suffering from low computational efficiency.To address these issues,we introduce a novel framework,Fed-MFSDHBCPSO—federated MFS via dual-layer hybrid breeding cooperative particle swarm optimization algorithm with manifold and sparsity regularization(DHBCPSO-MSR).Leveraging the federated learning paradigm,Fed-MFSDHBCPSO allows clients to perform local feature selection(FS)using DHBCPSO-MSR.Locally selected feature subsets are encrypted with differential privacy(DP)and transmitted to a central server,where they are securely aggregated and refined through secure multi-party computation(SMPC)until global convergence is achieved.Within each client,DHBCPSO-MSR employs a dual-layer FS strategy.The inner layer constructs sample and label similarity graphs,generates Laplacian matrices to capture the manifold structure between samples and labels,and applies L2,1-norm regularization to sparsify the feature subset,yielding an optimized feature weight matrix.The outer layer uses a hybrid breeding cooperative particle swarm optimization algorithm to further refine the feature weight matrix and identify the optimal feature subset.The updated weight matrix is then fed back to the inner layer for further optimization.Comprehensive experiments on multiple real-world multi-label datasets demonstrate that Fed-MFSDHBCPSO consistently outperforms both centralized and federated baseline methods across several key evaluation metrics. 展开更多
关键词 Multi-label feature selection federated learning manifold regularization sparse constraints hybrid breeding optimization algorithm particle swarm optimizatio algorithm privacy protection
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Every Sub-Riemannian Manifold Is the Gromov–Hausdorff Limit of a Sequence Riemannian Manifolds 被引量:1
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作者 Yong Hong HUANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2017年第11期1565-1568,共4页
In this paper, we will show that every sub-Riemannian manifold is the Gromov-Hausdorff limit of a sequence of Riemannian manifolds.
关键词 Riemannian manifold sub-riemannian manifold Gromov-Hausdorff convergence
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Non-embedding theorems of nilpotent Lie groups and sub-Riemannian manifolds
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作者 Yonghong HUANG Shanzhong SUN 《Frontiers of Mathematics in China》 SCIE CSCD 2020年第1期91-114,共24页
Wo prove that there do not exist quasi-isometric embeddings of connected nonabelian nilpotent Lie groups equipped with left invariant Riemannian metrics into a metric measure space satisfying the curvature-dimension c... Wo prove that there do not exist quasi-isometric embeddings of connected nonabelian nilpotent Lie groups equipped with left invariant Riemannian metrics into a metric measure space satisfying the curvature-dimension condition RCD(Q,N)with N∈R and N>1.In fact,we can prove that a sub-Riemannian manifold whose generic degree of nonholonomy is not smaller than 2 cannot be bi-Lipschitzly embedded in any Banach space with the Radon-Nikodym property.We also get that every regular sub-Riemannian manifold do not satisfy the curvature-dimension condition CD(K,N),where K,N∈R and N>1.Along the way to the proofs,we show that the minimal weak upper gradient and the horizontal gradient coincide on the Carnot-Caratheodory spaces which may have independent interests. 展开更多
关键词 NILPOTENT LIE group curvature-dimension condition bi-Lipschitz embedding sub-riemannian manifold
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Sub-Riemannian Limits,Connections with Torsion and the Gauss-Bonnet Theorem for Four Dimensional Twisted BCV Spaces
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作者 LI Hong-feng LIU Ke-feng WANG Yong 《Chinese Quarterly Journal of Mathematics》 2025年第2期111-134,共24页
In this paper,we compute sub-Riemannian limits of some important curvature variants associated with the connection with torsion for four dimensional twisted BCV spaces and derive a Gauss-Bonnet theorem for four dimens... In this paper,we compute sub-Riemannian limits of some important curvature variants associated with the connection with torsion for four dimensional twisted BCV spaces and derive a Gauss-Bonnet theorem for four dimensional twisted BCV spaces. 展开更多
关键词 Gauss-Bonnet theorem sub-riemannian limit Twisted BCV spaces Orthogonal connections with torsion
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Effects of Manifold Structures on Velocity Distribution of V-and A-Type Microchannel Plates
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作者 Pingnan Huang Liqing Ye 《Journal of Electronic Research and Application》 2025年第5期38-46,共9页
Flow velocity uniformity of the microchannel plate is a major factor affecting the performance of microchannel devices.In order to improve the velocity distribution uniformity of the microchannel plate,we designed two... Flow velocity uniformity of the microchannel plate is a major factor affecting the performance of microchannel devices.In order to improve the velocity distribution uniformity of the microchannel plate,we designed two new microchannel structures:V-type and A-type.The effects of various structural parameters of the manifolds on the velocity distribution are reported.The V-type and A-type microchannel plates had a more uniform velocity distribution compared to the Z-type microchannel plate.The final result showed that it is beneficial for the V-type microchannel plate to obtain a more uniform velocity distribution when the manifold structure parameters are X_(in)=-1,X_(out)=0,Y_(in)=10,Y_(out)=6,Hin=4,H_(out)=1,and R=0.5. 展开更多
关键词 MICROCHANNEL Velocity distribution manifoldS Structure optimization
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Manifold-Optimized Error-State Kalman Filter for Robust Pose Estimation in Unmanned Aerial Vehicles
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作者 Bolin Jia Zongwen Bai +5 位作者 Yiqun Gao Dong Wang Meili Zhou Peiqi Gao Pei Zhang Zhang Yang 《Journal of Electronic Research and Application》 2025年第2期247-257,共11页
This paper presents a manifold-optimized Error-State Kalman Filter(ESKF)framework for unmanned aerial vehicle(UAV)pose estimation,integrating Inertial Measurement Unit(IMU)data with GPS or LiDAR to enhance estimation ... This paper presents a manifold-optimized Error-State Kalman Filter(ESKF)framework for unmanned aerial vehicle(UAV)pose estimation,integrating Inertial Measurement Unit(IMU)data with GPS or LiDAR to enhance estimation accuracy and robustness.We employ a manifold-based optimization approach,leveraging exponential and logarithmic mappings to transform rotation vectors into rotation matrices.The proposed ESKF framework ensures state variables remain near the origin,effectively mitigating singularity issues and enhancing numerical stability.Additionally,due to the small magnitude of state variables,second-order terms can be neglected,simplifying Jacobian matrix computation and improving computational efficiency.Furthermore,we introduce a novel Kalman filter gain computation strategy that dynamically adapts to low-dimensional and high-dimensional observation equations,enabling efficient processing across different sensor modalities.Specifically,for resource-constrained UAV platforms,this method significantly reduces computational cost,making it highly suitable for real-time UAV applications. 展开更多
关键词 UAV pose estimation Error-State Kalman Filter manifold GPS LIDAR
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A Note on Cohomological Mirror Symmetry of Toric Manifolds
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作者 Hao Wen 《Communications in Mathematical Research》 2025年第3期271-286,共16页
In this note we describe a logarithmic version of mirror Landau-Ginzburg model for semi-projective toric manifolds and show in an elementary and explicit way that the state space ring of the Landau-Ginzburg mirror is ... In this note we describe a logarithmic version of mirror Landau-Ginzburg model for semi-projective toric manifolds and show in an elementary and explicit way that the state space ring of the Landau-Ginzburg mirror is isomorphic to the C-valued cohomology of the toric manifold. 展开更多
关键词 Mirror symmetry Landau-Ginzburg model toric manifold
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VANISHING THEOREMS OF THE BASIC P-HARMONIC FORMS ON COMPLETE FOLIATED RIEMANNIAN MANIFOLDS
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作者 NIE Yan-ci SHEN Zheng-han 《数学杂志》 2025年第3期195-204,共10页
In this paper,we study the basic p-harmonic forms on the complete foliated Riemannian manifolds.By using the method in[1],we show that if the basic mean curvature form is bounded and co-closed,and the transversal curv... In this paper,we study the basic p-harmonic forms on the complete foliated Riemannian manifolds.By using the method in[1],we show that if the basic mean curvature form is bounded and co-closed,and the transversal curvature operator is nonnegative and positive at least one point,then we obtain a vanishing theorem for L^(p)-integrably p-harmonic r-forms. 展开更多
关键词 basic p-harmonic form vanishing theorem foliated Riemannian manifold
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A Compact Manifold Mixup Feature-Based Open-Set Recognition Approach for Unknown Signals
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作者 Yang Ying Zhu Lidong +1 位作者 Li Chengjie Sun Hong 《China Communications》 2025年第4期322-338,共17页
There are all kinds of unknown and known signals in the actual electromagnetic environment,which hinders the development of practical cognitive radio applications.However,most existing signal recognition models are di... There are all kinds of unknown and known signals in the actual electromagnetic environment,which hinders the development of practical cognitive radio applications.However,most existing signal recognition models are difficult to discover unknown signals while recognizing known ones.In this paper,a compact manifold mixup feature-based open-set recognition approach(OR-CMMF)is proposed to address the above problem.First,the proposed approach utilizes the center loss to constrain decision boundaries so that it obtains the compact latent signal feature representations and extends the low-confidence feature space.Second,the latent signal feature representations are used to construct synthetic representations as substitutes for unknown categories of signals.Then,these constructed representations can occupy the extended low-confidence space.Finally,the proposed approach applies the distillation loss to adjust the decision boundaries between the known categories signals and the constructed unknown categories substitutes so that it accurately discovers unknown signals.The OR-CMMF approach outperformed other state-of-the-art open-set recognition methods in comprehensive recognition performance and running time,as demonstrated by simulation experiments on two public datasets RML2016.10a and ORACLE. 展开更多
关键词 manifold mixup open-set recognition synthetic representation unknown signal recognition
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Deep Fusion of Intrinsic Vibration Information and Grassmann Manifold-based Similarity for Fault Identification of Reciprocating Compressor
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作者 Ying Zhang Jinchen Ji Xiaowang Chen 《Journal of Dynamics, Monitoring and Diagnostics》 2025年第1期1-10,共10页
This paper introduces a new method based on deep belief networks(DBNs)to integrate intrinsic vibration information and assess the similarity of subspaces established on the Grassmann manifold for intelligent fault dia... This paper introduces a new method based on deep belief networks(DBNs)to integrate intrinsic vibration information and assess the similarity of subspaces established on the Grassmann manifold for intelligent fault diagnosis of a reciprocating compressor(RC).Initially,raw vibration signals undergo empirical mode decomposition to break them down into multiple intrinsic mode functions(IMFs).This operation can reveal inherent vibration patterns of fault and other components hidden in the original signals.Subsequently,features are refined from all the IMFs and concatenated into a high-dimensional representative vector,offering localized and comprehensive insights into RC operation.Through DBN,the fault-sensitive information is further refined from the features to enhance their performance in fault identification.Finally,similarities among subspaces on the Grassmann manifold are computed to match fault types.The efficacy of the method is validated usingfield data.Comparative analysis with traditional approaches for feature dimension reduction,feature extraction,and Euclidean distance-based fault identification underscores the effectiveness and superiority of the proposed method in RC fault diagnosis. 展开更多
关键词 deep belief network empirical mode decomposition fault diagnosis Grassmann manifold intrinsic vibration reciprocating compressor
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C^(2)estimates for a class of degenerate k-Hessian equations with gradient terms on closed Hermitian manifolds
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作者 WU Hanqing XU Lu 《纯粹数学与应用数学》 2025年第1期25-45,共21页
In this article,we are concerned with the C^(2)estimates for the k-convex solutions of a class of degenerate k-Hessian equations on closed Hermitian manifolds,whose function in the right-hand side is relevant to the u... In this article,we are concerned with the C^(2)estimates for the k-convex solutions of a class of degenerate k-Hessian equations on closed Hermitian manifolds,whose function in the right-hand side is relevant to the unknown function and its gradient.We will get C^(0)estimate by promoting others′results,and get the“HMW estimate”of this equation such that the conditions of using blow-up analysis are satisfied,and the gradient estimate and second-order estimate will be obtained.Such an estimate will be helpful to study the existence for the solution of the equation. 展开更多
关键词 C^(2)estimates degenerate k-Hessian equation closed Hermitian manifold
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3D numerical manifold method for crack propagation in rock materials using a local tracking algorithm
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作者 Boyi Su Tao Xu +3 位作者 Genhua Shi Michael J.Heap Xianyang Yu Guanglei Zhou 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第6期3449-3463,共15页
The modeling of crack growth in three-dimensional(3D)space poses significant challenges in rock mechanics due to the complex numerical computation involved in simulating crack propagation and interaction in rock mater... The modeling of crack growth in three-dimensional(3D)space poses significant challenges in rock mechanics due to the complex numerical computation involved in simulating crack propagation and interaction in rock materials.In this study,we present a novel approach that introduces a 3D numerical manifold method(3D-NMM)with a geometric kernel to enhance computational efficiency.Specifically,the maximum tensile stress criterion is adopted as a crack growth criterion to achieve strong discontinuous crack growth,and a local crack tracking algorithm and an angle correction technique are incorporated to address minor limitations of the algorithm in a 3D model.The implementation of the program is carried out in Python,using object-oriented programming in two independent modules:a calculation module and a crack module.Furthermore,we propose feasible improvements to enhance the performance of the algorithm.Finally,we demonstrate the feasibility and effectiveness of the enhanced algorithm in the 3D-NMM using four numerical examples.This study establishes the potential of the 3DNMM,combined with the local tracking algorithm,for accurately modeling 3D crack propagation in brittle rock materials. 展开更多
关键词 3D numerical manifold method(3D NMM) Crack propagation Local tracking algorithm Brittle materials
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多层金属垫片的高温压缩-回弹特性分析
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作者 覃文洁 华青格乐 张金歌 《北京理工大学学报》 北大核心 2026年第1期103-110,共8页
垫片的压缩—回弹曲线是分析螺栓法兰接头的接触情况所必需的,而柴油机排气歧管前端法兰组件中垫片部位的温度通常达到500℃左右,难以通过实验获得.为此针对某高功率柴油机排气歧管前端法兰的多层金属垫片,建立了模拟该垫片压缩-回弹实... 垫片的压缩—回弹曲线是分析螺栓法兰接头的接触情况所必需的,而柴油机排气歧管前端法兰组件中垫片部位的温度通常达到500℃左右,难以通过实验获得.为此针对某高功率柴油机排气歧管前端法兰的多层金属垫片,建立了模拟该垫片压缩-回弹实验的有限元模型,通过接触动力学分析得到了其在室温和200℃下的压缩—回弹曲线,并与相应的实验结果对比,验证了所建模型的准确性,进一步分析得到了高温下该垫片的压缩−回弹曲线.结果表明常温时垫片的最大压缩量为0.522 mm,温度升至700℃时最大压缩量则升至0.762 mm,同时中间层垫片发生塑性变形的临界载荷减小,曲线的压缩段与回弹段的间距也增大.使用室温以及500℃下的垫片压缩—回弹曲线计算柴油机排气歧管前端法兰的接触应力,得到垫片最小接触应力分别为5.57 MPa和6.95 MPa,误差达到20%,说明采用不同温度的垫片压缩-回弹曲线对排气歧管前端法兰的接触应力分布计算会造成较大影响. 展开更多
关键词 多层金属垫片 排气歧管前端法兰 压缩-回弹 高温影响
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Singular Points, Closed Orbits, Stable Manifolds and Unstable Manifolds of Second Order Autonomous Birkhoff Systems 被引量:1
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作者 陈向炜 梅凤翔 《Journal of Beijing Institute of Technology》 EI CAS 1998年第4期330-336,共7页
Aim To study singular points, closed orbits, stable manifolds and unstable manifolds of a second order autonomous Birkhoff system. Methods Qualitative methods of ordinary differential equation were used. Results and ... Aim To study singular points, closed orbits, stable manifolds and unstable manifolds of a second order autonomous Birkhoff system. Methods Qualitative methods of ordinary differential equation were used. Results and Conclusion The criteria for singular points, closed orbits and hyperbolic equilibrium points of a second order autonomous Birkhoff system are given. Moreover the stability of equilibria, stable manifolds and unstable manifolds are obtained. 展开更多
关键词 Birkhoff system singular point closed orbit stable manifold unstable manifold
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基于Manifold Ranking和结合前景背景特征的显著性检测 被引量:7
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作者 朱征宇 汪梅 《计算机应用》 CSCD 北大核心 2016年第9期2560-2565,共6页
针对基于图和流形排序(Manifold Ranking)的显著性检测算法(MR算法)过度依赖边界节点的背景特征的问题,提出一种改进的结合前景背景特征的显著性检测算法。首先,对图像进行超像素分割,建立闭环图模型;然后利用流形排序算法根据图像前景... 针对基于图和流形排序(Manifold Ranking)的显著性检测算法(MR算法)过度依赖边界节点的背景特征的问题,提出一种改进的结合前景背景特征的显著性检测算法。首先,对图像进行超像素分割,建立闭环图模型;然后利用流形排序算法根据图像前景特征和背景特征分别得出前景种子和背景种子;再通过亮度和颜色特征对两类种子进行结合,筛选出更为准确的查询节点;最后再利用流形排序算法进行显著值计算,得到最终的显著图。实验表明,改进方法与MR算法相比在精确率、召回率、F值等多个评价指标上均有明显提升,得到的显著图更接近真值。 展开更多
关键词 显著性检测 流形排序 查询节点 显著图 显著区域
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CR-submanifolds in Almost Hermitian Manifold
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作者 许志才 徐森林 《Chinese Quarterly Journal of Mathematics》 CSCD 2001年第3期1-7,共7页
Studies are made of the cohomology of CR_ submanifolds and integrability of the distribution D of CR_submanifolds. When dim D⊥】1, the totally umbilical non-trival CR-submanifold i n nea r Kaehler manifold is totall... Studies are made of the cohomology of CR_ submanifolds and integrability of the distribution D of CR_submanifolds. When dim D⊥】1, the totally umbilical non-trival CR-submanifold i n nea r Kaehler manifold is totally geodesic. In the end, we get:If is n ear Kaehler manifold with B】0, then is not permitt ed to have fixed foliate non-trival CR-submanifold. 展开更多
关键词 SUBmanifold complex manifold almost complex manifold DISTRIBUTION INTEGRABILITY
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基于流固耦合的特高压节流压井管汇强度分析
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作者 戴启平 张绪亮 +3 位作者 刘鸣 魏军会 张耀明 甯尤军 《石油矿场机械》 2026年第1期39-45,共7页
针对特高压节流压井管汇系统的流场载荷特性及管道强度等问题,利用Ansys Workbench软件对节流压井管汇的管道进行流固耦合进行模拟分析。为验证不同介质对管道流场和管道受力特性的影响,模拟了三种流体介质(钻井液、甲烷以及钻井液与甲... 针对特高压节流压井管汇系统的流场载荷特性及管道强度等问题,利用Ansys Workbench软件对节流压井管汇的管道进行流固耦合进行模拟分析。为验证不同介质对管道流场和管道受力特性的影响,模拟了三种流体介质(钻井液、甲烷以及钻井液与甲烷的两相流)的流动情况和管道受力状况;为研究出口闭合对流场及管道的影响,分析了不同出口开闭组合的管道流场特性和管道受力特性。结果表明,甲烷流体产生的流场局部流速更大,对管道的压力也更大;出口开启越小,管道受到的压力越大,管道的危险性越大;在甲烷流体作用下,节流压井管汇管道会在管道相贯处出现局部屈服,但管道大部分区域仍处于弹性范围内。研究成果可为特高压管道的设计、制造及工程应用提供理论依据。 展开更多
关键词 特高压 节流压井管汇 流固耦合 载荷特性 管道强度
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On the Comparison Theorems for the Volume of Tubes in Kahlerian Manifolds
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作者 陈维桓 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第2期91-100,共10页
In this note we give some comparison theorems for the volume of tubes around a complex submanifold in a Kahlerian monifold.
关键词 Kahlerian manifold TUBE VOLUME comparison theorem
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