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钟鸣鼎食的贾府何以衰败

文史杂志 2025年第1期235卷 52-56页

作者：杨武四川华奥科普传媒研究所研究室

《红楼梦》作为中国古典四大名著之一,其深刻描绘的贾府兴衰史一直为读者津津乐道。然而,它关于贾府衰败的具体原因却并未完全交代清楚。历来的红学者和读者在探讨贾府衰败问题时,多认为经济破产是其重要原因,其实皇权压迫、政治失势才... 详细信息

《红楼梦》作为中国古典四大名著之一,其深刻描绘的贾府兴衰史一直为读者津津乐道。然而,它关于贾府衰败的具体原因却并未完全交代清楚。历来的红学者和读者在探讨贾府衰败问题时,多认为经济破产是其重要原因,其实皇权压迫、政治失势才是主要原因。

关键词：红学曹雪芹经济收支官场争斗勋贵世家

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跨境电子商务质量保障标准化现状及需求

质量与认证 2025年第1期 30-31页

作者：吴杨汪莉中国质量认证中心

本文分析中国跨境电商质量保障标准化的现状和需求,指出市场准入和后市场监管阶段的质量保障挑战,并有针对性地提出了应对措施。在标准化工作现状方面,总结国家和国际层面已经制定的一系列标准。在标准化需求方面,强调跨境电商产品合规... 详细信息

本文分析中国跨境电商质量保障标准化的现状和需求,指出市场准入和后市场监管阶段的质量保障挑战,并有针对性地提出了应对措施。在标准化工作现状方面,总结国家和国际层面已经制定的一系列标准。在标准化需求方面,强调跨境电商产品合规的新要求,并给出下一步标准化方向建议。

关键词：跨境电子商务跨境电商市场监管质量保障标准化方向标准化工作市场准入应对措施

Structural Nonlinear Flutter Characteristics Analysis for an Actuator-fin System with Dynamic Stiffness

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Chinese Journal of Aeronautics 2011年第5期24卷 590-599页

作者： yang Ning wu Zhigang yang Chao School of Aeronautic Science and Engineering Beihang University Beijing 100191 China

The flutter characteristics of an actuator-fin system are investigated with structural nonlinearity and dynamic stiffness of the electric motor. The component mode substitution method is used to establish the nonlinear governing equations in time domain and frequency domain based on the fundamental dynamic equations of the electric motor and decelerator. The existing describing function method and a proposed iterative method are used to obtain the flutter characteristics containing preload freeplay nonlinearity when the control command is zero. A comparison between the results of frequency domain and those of time domain is studied. Simulations are carried out when the control command is not zero and further analysis is conducted when the freeplay angle is changed. The results show that structural nonlinearity and dynamic stiffness have a significant influence on the flutter characteristics. Limit cycle oscillations （LCOs） are observed within linear flutter boundary. The response of the actuator-fin system is related to the initial disturbance. In the nonlinear condition, the amplitude of the control command has an influence on the flutter characteristics.

关键词： aeroelasticity flutter actuators dynamic stiffness structural nonlinearity component mode substitution method describing functions

Curvature, Diameter and Bounded Betti Numbers

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Chinese Annals of Mathematics,Series B 2006年第2期27卷 143-152页

作者： Jyh-yang wu Dedicated to the memory of Shiing-Shen Chern

In this paper, we introduce the notion of bounded Betti numbers, and show that the bounded Betti numbers of a closed Riemannian n-manifold （M, g） with Ric （M） ≥ -（n - 1） and Diam （M） ≤D are bounded by a number depending on D and n. We also show that there are only finitely many isometric isomorphism types of bounded cohomology groups （H（M）,Ⅱ·Ⅱ∞） among closed Riemannian manifold （M, g） with K（M） ≥ -1 and Diam （M） ≤ D.

关键词： Diameter Ricci curvature Sectional curvature Bounded cohomology Bounded Betti number

Two-dimensional semiconductor heterostructures for photocatalytic CO_(2)conversion

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Science China Chemistry 2024年第8期67卷 2434-2447页

作者： yang wu Mingyu wu Yongfu Sun Yi Xie Hefei National Research Center for Physical Sciences at Microscale University of Science and Technology of ChinaHefei 230026China

The CO_(2)reduction into carbon-contained fuel via solar energy offers the powerful tools to realize the zero-emission carbon *** to the intriguing features of the two-dimensional(2D)heterostructures,it is susceptible to modulate the electronic structure as well as the surface geometry for optimizing the photocatalytic CO_(2)*** this perspective,we surveyed the fundamental insights of 2D semiconductor heterostructures,involving the fabrication strategies and classification of the 2D semiconductor ***,we have detailly discussed the overview of 2D semiconductor heterostructure for optimizing CO_(2)photocatalytic influenced factors,including the solar energy utilization,photogenerated carriers separation,and redox reaction ***,we showed the significant advantages of 2D heterostructures in elevating CO_(2)photoreduction performance,focusing on activity,selectivity and *** analyzing the limitations and developments,we ended by putting forward insights into the further researches about the CO_(2)photocatalysts and reactor design,even industrial applications.

关键词： two-dimensional semiconductor heterostructures photocatalysis CO_(2)conversion

NUMERICAL SIMULATION OF A HORIZONTAL MOMENTUM JET IN CROSS-FLOW

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Journal of Hydrodynamics 2006年第1期18卷 118-125页

作者： XIAO yang TANG Hong-wu College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China

The mixing characteristics of a Horizontal Momentum Jet in Cross flow （HMJC） were investigated using the CFD code Fluent. The realizable k-ε model was employed for turbulent closure of the Reynolds-averaged Navier-Stokes equations. The computed results, including concentration field and velocity field, agree well with the relations of dimen sional analysis, as well as the experimental results by Sherif and Pletcher, Ali and Yu et al.

关键词： horizontal momentum jet cross-flow realizable k-ε model LIF PIV

C^1 conforming quadrilateral finite elements with complete secondorder derivatives on vertices and its application to Kirchhoff plates

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Science China(Technological Sciences) 2020年第6期63卷 1066-1084页

作者： wu yang XING YuFeng LIU Bo Institute of Solid Mechanics Beihang UniversityBeijing 100191China

The classical problem of the construction of C^1 conforming single-patch quadrilateral finite elements has been solved in this investigation by using the blending function interpolation *** order to achieve the C^1 conformity on the interfaces of quadrilateral elements,complete second-order derivatives are used at the element vertices,and the information of geometrical mapping is also considered into the construction of shape *** is found that the shape functions and the polynomial spaces of the present elements vary with element ***,the developed quadrilateral elements are at least third order for general quadrilateral shapes and fifth order for rectangular ***,very fast convergence can be achieved.A promising feature of the present elements is that they can be used in cooperation with those high-precision rectangular and triangular *** the present elements are over conforming on element vertices,an approach for handling problems of material discontinuity is also *** examples of Kirchhoff plates are employed to demonstrate the computational performance of the present elements.

关键词： finite element method quadrilateral elements C^1 conforming Kirchhoff plates

CR-Morph: Controllable Rigid Morphing for 2D Animation

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Journal of Computer Science & Technology 2019年第5期34卷 1109-1122页

作者： Wen-wu yang Jing Hua Kun-yang Yao School of Computer and Information Engineering Zhejiang Gongshang UniversityHangzhou 310012China Department of Computer Science Wayne State UniversityMichigan 48202U.S.A.

This paper presents a rigidity-preserving morphing technique that blends a pair of 2D shapes in a controllable manner. The morphing is controllable in two aspects: 1) motion dynamics in the interpolation sequences can be effectively enhanced through an intuitive skeleton control and 2) not only the boundaries but also the interior features of the source and target shapes are precisely aligned during the morphing. We introduce a new compatible triangulation algorithm to decompose the source and target shapes into isomorphic triangles. Moreover, a robust and motion-controllable rigiditypreserving transformation scheme is proposed to blend the compatible triangulations, ultimately leading to a morphing sequence which is appearance-preserving and with the desired motion dynamics. Our approach constitutes a powerful and easy-to-use morphing tool for two-dimensional animation. We demonstrate its versatility, effectiveness and visual accuracy through a variety of examples and comparisons to prior work.

关键词： compatible triangulation disc-based interpolation rigid morphing skeleton-based dynamics

A polypyrrole-coated acetylene black/sulfur composite cathode material for lithium–sulfur batteries

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Journal of Energy Chemistry 2018年第3期27卷 813-819页

作者： wu yang Wang yang Jiani Feng Xiujuan Qin Hebei Key Laboratory of Applied Chemistry College of Environmental and Chemical Engineering Yanshan University State key Laboratory of Metastable Materials Science and Technology Yanshan University

Lithium–sulfur batteries are promising next-generation energy storage devices beyond conventional lithium ion batteries. However, it suffers from rapid capacity fading and poor cyclic stability. Here we report a facile in situ sulfur deposition and chemical oxidative polymerization method for preparing acetylene black/sulfur@polypyrrole（AB/S@PPy） composite as a cathode material for lithium–sulfur batteries. It is demonstrated that PPy is covered uniformly onto the surface of the AB/S composite forming a core–shell structure. In the structure, AB in the matrix and PPy on the surface acts as a combined conductive framework to provide ions and electrons transport pathways, and to inhibit the dissolution or diffusion of polysulfide into the electrolyte. The as-designed AB/S@PPy composite exhibits excellent rate capability and cyclic stability. The initial discharge specific capacity is as high as 1179.4 m Ah/g, and remains at769.3 m Ah/g after 80 cycles at 0.2 C. Even at a high rate（0.5 C）, a maximum discharge capacity of 811.1 m Ah/g is still achieved for the AB/S@PPy composite after activation, and the capacity retention is over62.5% after 200 cycles.

关键词： Lithium-sulfur batteries Acetylene black Polypyrrole Core–shell