检索结果-南通市图书馆

Anisotropic Curl-free Wavelet Bases on the Unit Cube

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2013年第4期29卷 801-814页

作者： ying Chun jiang School of Mathematics and Computational Science Guilin University of Electronic Technology

This paper deals with the construction of anisotropic curl-free wavelets on the cube [0,1]3, which satisfies the specific boundary conditions. First, one constructs curl-free wavelets on the unit cube based on one dimensional wavelets on the interval [0,1] with some boundary conditions. Then, the stability of the corresponding wavelets in curl-free space and the characterization of Sobolev spaces are studied. Finally, one gives a Helmholtz decomposition and the representation of curl and div operators in wavelet coordinates.

关键词： Wavelets anisotropic curl-free cube Helmholtz decomposition

Particle Distribution Informed by Chain Rigidity in Diblock Copolymer Melts: The Effect of Entropy

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第3期42卷 388-399,I0009页

作者： Yuguo Chen Shuanhu Qi ying jiang School of Chemistry Beihang UniversityBeijing 100191China

We study the effect of chain rigidity on tailoring the nanoparticle locations for neutral and selective particles embedded in the lamellar morphology formed by semiflexible diblock copolymer chains using self-consistent field calculations. The nanoparticles are modeled through a cavity function, and the semiflexible chains are represented by the continuous Kratsky-Porod chain model. In general situation, the nanoparticles prefer to stay at the interface in order to reduce the interface areas and thus the system free energy. However, the particle distribution at the domain center is subtle, and the underlying physics is intrinsically different depending on the polymer flexibility. In the case of flexible chains, the entropy just contributes a constant shift to the free energy when the nanoparticles move around the domain center indicating that the local metastable state if appears at the domain center is wholly attributed to the local minimum in the enthalpy. If the polymers are rigid, the variation of the particle distribution at the domain center has a close relation with the polymer rigidity and nanoparticle size. In the case of strongly rigid polymers with small nanoparticles, a nearly uniform particle distribution at the domain center is observed, while in other cases, a local enhancement of particle distribution there is found. In contrast to the case of flexible chains, further analysis reveals the crucial role of entropy in controlling the shape of particle distributions at the phase domain. Specifically, the local metastable state appears in the domain center is determined by the large entropy there which arises from the weak coupling of bond orientations that allows the polymer chains to be relatively relaxed. When the particle becomes selective, its distribution in the phase domain exhibits a shift almost uniformly rather than changes its profile, and the underlying physics still holds. In all, our study establishes a strong coupling between the chain rigi

关键词： Semiflexible diblock copolymer Nanoparticle distribution Self-consistent field theory Entropic effect

Ultrafast optical investigation of carrier and spin dynamics in low-dimensional perovskites

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第1期67卷 2-18页

作者： FU JinYue jiang ying FANG HongHua Key Laboratory for Micro-Nano Physics and Technology of Hunan Province School of Physics and ElectronicsHunan UniversityChangsha 410012China State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China

Low-dimensional perovskite(PVK)materials have attracted significant research interest,because of their quantum-confined effect,tunable band gap structures,and higher stability than that of three-dimensional(3D)*** semiconductor optoelectronic devices,high speed and small size are closely *** development of high-speed devices requires researchers to fully understand the properties of materials,especially the dynamic processes such as carrier recombination,separation,and transport,which often play a crucial role in the performance of *** an indispensable part of dynamic research,spin relaxation is also of great significance in studying the properties of materials and explore possible *** halide PVK materials have strong spin-orbit coupling(SOC),which provides a basis for information storage and processing by using spin degrees of ***,studying the carrier and spin dynamics of low-dimensional PVKs is an effective way to understand the internal properties of low-dimensional PVKs *** paper summarizes the latest research progress on the ultrafast carrier and spin dynamics in low-dimensional PVKs,to comprehensively understand their carrier and spin behaviors and present an outlook for relevant studies in this area.

关键词： low-dimensional perovskites carrier dynamics spin dynamics optoelectronic devices

3D analytical solution for a rotating transversely isotropic annular plate of functionally graded materials

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第7期8卷 1038-1043页

作者： CHEN jiang-ying CHEN Wei-qiu Faculty of Engineering Ningbo University Ningbo 315211 China Department of Civil Engineering Zhejiang University Hangzhou 310027 China

The analytical solution for an annular plate rotating at a constant angular velocity is derived by means of direct displacement method from the elasticity equations for axisymmetric problems of functionally graded transversely isotropic media. The displacement components are assumed as a linear combination of certain explicit functions of the radial coordinate, with seven undetermined coefficients being functions of the axial coordinate z. Seven equations governing these z-dependent functions are derived and solved by a progressive integrating scheme. The present solution can be degenerated into the solution of a rotating isotropic functionally graded annular plate. The solution also can be degenerated into that for transversely isotropic or isotropic homogeneous materials. Finally, a special case is considered and the effect of the material gradient index on the elastic field is illustrated numerically.

关键词： Functionally graded materials Transversely isotropic Rotating annular plate Analytical solution

A fully abstract semantics for value-passing CCS for trees

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2019年第4期13卷 828-849页

作者： ying jiang Shichao LIU Thomas EHRHARD State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China CNRS IRIF UMR 8243 Univ Paris Diderot Sorbonne Paris Cite F-75205 Paris France

We propose a fully abstract semantics for valuepassing CCS for trees (VCCTS) with the feature that processes are located at the vertices of a graph whose edges describe possible interaction capabilities. The operational semantics is given both in terms of a reduction semantics and in terms of a labelled transition semantics. We develop a theory of behavioral equivalences by introducing both weak barbed congruence and weak bisimilarity. In particular, we show that, on image-finite processes, weak barbed congruence coincides with weak bisimilarity. To illustrate potential applications and the powerful expressiveness of VCCTS, we formally compare VCCTS with some well-known models, e.g., dynamic pushdown networks, top-down tree automata and value-passing CCS.

关键词： process calculus non-interleaving semantics barbed congruence bisimulation

Atomic-level characterization of liquid/solid interface

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第11期29卷 25-36页

作者： Jiani Hong ying jiang International Center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China Collaborative Innovation Center of Quantum Matter Beijing 100871China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100190China

The detailed understanding of various underlying processes at liquid/solid interfaces requires the development of interface-sensitive and high-resolution experimental techniques with atomic *** this perspective,we review the recent advances in studying the liquid/solid interfaces at atomic level by electrochemical scanning tunneling microscope(EC-STM),non-contact atomic force microscopy(NC-AFM),and surface-sensitive vibrational *** from the ultrahigh vacuum and cryogenic experiments,these techniques are all operated in situ under ambient condition,making the measurements close to the native state of the liquid/solid *** the end,we present some perspectives on emerging techniques,which can defeat the limitation of existing imaging and spectroscopic methods in the characterization of liquid/solid interfaces.

关键词： liquid/solid interface atomic scale scanning tunneling microscope(STM) atomic force microscopy(AFM)

Adaptive Wavelet Solution to the Stokes Problem

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2008年第4期24卷 613-626页

作者： ying-chun jiang Youming Liu College of Mathematics and Computer Sciences Guilin University of Electronic Technology Cuilin 541004 China Department of Applied Mathematics Beijing University of Technology Beijing 100022 China

This paper deals with the design and analysis of adaptive wavelet method for the Stokes problem. First, the limitation of Richardson iteration is explained and the multiplied matrix M0 in the paper of Bramble and Pasciak is proved to be the simplest possible in an appropiate sense. Similar to the divergence operator, an exact application of its dual is shown; Second, based on these above observations, an adaptive wavelet algorithm for the Stokes problem is designed. Error analysis and computational complexity are given; Finally, since our algorithm is mainly to deal with an elliptic and positive definite operator equation, the last section is devoted to the Galerkin solution of an elliptic and positive definite equation. It turns out that the upper bound for error estimation may be improved.

关键词： Richardson iteration adaptive algorithm wavelets Stokes problem Galerkin solution

Generation of Non-Gaussian Random Vibration Excitation Signal for Reliability Enhancement Test

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2007年第3期20卷 236-239页

作者： YU ying-yang jiang Tong-min Department of System Engineering of Engineering Technolog） Beijing University of Aeronautics and Astronautics Beijing 100083 China

During environment testing, the time histories of some dynamic environments follow non-Gaussian distribution. It is always assumed that the random vibration simulated follows Gaussian distribution, because the traditional digital random vibration control system can only supply the random vibration excitation signal of Gaussian. Yo simulate the real environment of product, a method is developed in this paper that can generate non-Gaussian random signal with specified power spectrum density （PSD）, skewness and kurtosis by shot noise. In this way, non-Gaussian random vibration can be produced on traditional electrodynamic shaker. It solves the problems of spectral valley and energy shortage in low frequency on omni-axis shaker. At last, the wavelet is used to analyze the non-Gaussian signal

关键词： non-Gaussian shot noise skewness kurtosis wavelet

Recent Progress on Highly Selective and Sensitive Electrochemical Aptamer-based Sensors

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2022年第4期38卷 866-878页

作者： TANG Tianwei LIU yinghuan jiang ying College of Chemistry Beijing Normal UniversityBeijing 100875P.R.China Beijing National Laboratory for Molecular Sciences Beijing 100190P.R.China

Highly selective,sensitive,and stable biosensors are essential for the molecular level understanding of many physiological activities and *** aptamer-based(E-AB)sensor is an appealing platform for measurement in biological system,attributing to the combined advantages of high selectivity of the aptamer and high sensitivity of electrochemical *** review summarizes the latest development of E-AB sensors,focuses on the modification strategies used in the fabrication of sensors and the sensing strategies for analytes of different sizes in biological system,and then looks forward to the challenges and prospects of the future development of electrochemical aptamerbased sensors.

关键词： Electrochemical biosensor Aptamer Biomolecular recognition Biological system