检索结果-南通市图书馆

Meshing stiffness property and meshing status simulation of harmonic drive under transmission loading

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2022年第2期17卷 145-163页

作者： Xiaoxia chen Yunpeng YAO Jingzhong xing School of Mechanical Engineering Tiangong UniversityTianjin 300387China Tianjin Key Laboratory of Modern Mechatronics Equipment Technology Tiangong UniversityTianjin 300387China

The multitooth meshing state of harmonic drive (HD) is an important basic characteristic of its high transformation precision and high bearing capacity. Meshing force distribution affects the load sharing of the tooth during meshing, and theoretical research remains insufficient at present. To calculate the spatial distributed meshing forces and loading backlashes along the axial direction, an iterative algorithm and finite element model (FEM) is proposed to investigate the meshing state under varied transmission loading. The displacement formulae of meshing point under tangential force are derived according to the torsion of the flexspline cylinder and the bending of the tooth. Based on the relationship of meshing forces and circumferential displacements, meshing forces and loading backlashes in three cross-sections are calculated with the algorithm under gradually increased rotation angles of circular spline, and the results are compared with FEM. Owing to the taper deformation of the cup-shaped flexspline, the smallest initial backlash and the earliest meshing point appear in the front cross-section far from the cup bottom, and then the teeth in the middle cross-section of the tooth rim enter the meshing and carry most of the loading. Theoretical and numerical research show that the flexibility is quite different for varied meshing points and tangential force amplitude because of the change of contact status between the flexspline and the wave generator. The meshing forces and torsional stiffness of the HD are nonlinear with the torsional angle.

关键词： harmonic drive meshing flexibility matrix meshing force loading backlash flexspline contact analysis

Variational Principle for Topological Pressure on Subsets of Free Semigroup Actions

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2021年第9期37卷 1401-1414页

作者： xing Fu ZHONG Zhi Jing chen School of Mathematics and Statistics Guangdong University of Foreign StudiesGuangzhou 510006P.R.China School of Mathematics and Systems Science Guangdong Polytechnic Normal UniversityGuangzhou 510665P.R.China

We investigate the relations between Pesin–Pitskel topological pressure on an arbitrary subset and measure-theoretic pressure of Borel probability measures for finitely generated semigroup ***(X,G)be a system,where X is a compact metric space and G is a finite family of continuous maps on *** a continuous function f on X,we define Pesin–Pitskel topological pressure PG(Z,f)for any subset Z■X and measure-theoretical pressure Pμ,G(X,f)for anyμ∈M(X),where M(X)denotes the set of all Borel probability measures on *** any non-empty compact subset Z of X,we show that PG(Z,f)=sup{Pμ,G(X,f):μ∈M(X),μ(Z)=1}.

关键词： Topological pressure measure-theoretic pressure semigroup of continuous maps variational principle

Theoretical study on anomalous thermal expansion of two AB_(2)-type compounds

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第11期17卷 9830-9833页

作者： Xin chen Yili Cao Xianran xing Beijing Advanced Innovation Center for Materials Genome Engineering and Institute of Solid State Chemistry University of Science and Technology Beijing Beijing 100083 China

Anomalous thermal expansion,or other words,negative thermal expansion(NTE),resulting from the lattice contraction upon temperature increasing,has been an enduring topic for material science and *** variation of a lattice go with the temperature is straightly originated from its electronic structures and is inseparable from those physical *** the past several decades,many efforts have been made to searching new series of NTE compounds or control the thermal expansion performance in order to supply various demands of different extreme *** development of new NTE systems also dependences on the theoretical ***,we carried out theoretical calculation on CrB_(2) and FeZr_(2) with anisotropic negative thermal ***,theoretical calculations reveal that the binding of either Cr-Cr pair or Fe-Fe pair is relatively *** results reveal that the origin of NTE is the ordered magnetic state during the increasing of *** localized electrons would prevent the lattice parameters increase with heating,which shows macroscopic NTE phenomenon.

关键词： negative thermal expansion(NTE) theoretical calculation magnet state transition band structures

Robust Local Light Field Synthesis via Occlusion-aware Sampling and Deep Visual Feature Fusion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Machine Intelligence Research 2023年第3期20卷 408-420页

作者： Wenpeng xing Jie chen Yike Guo Department of Computer Science Hong Kong Baptist UniversityHong Kong 999077China Data Science Institute Imperial College LondonLondon SW72AZUK

Novel view synthesis has attracted tremendous research attention recently for its applications in virtual reality and immersive *** a locally immersive light field(LF)based on arbitrary large baseline RGB references is a challenging problem that lacks efficient solutions with existing novel view synthesis *** this work,we aim at truthfully rendering local immersive novel views/LF images based on large baseline LF captures and a single RGB image in the target *** fully explore the precious information from source LF captures,we propose a novel occlusion-aware source sampler(OSS)module which efficiently transfers the pixels of source views to the target view′s frustum in an occlusion-aware *** attention-based deep visual fusion module is proposed to fuse the revealed occluded background content with a preliminary LF into a final refined *** proposed source sampling and fusion mechanism not only helps to provide information for occluded regions from varying observation angles,but also proves to be able to effectively enhance the visual rendering *** results show that our proposed method is able to render high-quality LF images/novel views with sparse RGB references and outperforms state-of-the-art LF rendering and novel view synthesis methods.

关键词： Novel view synthesis light field(LF)imaging multi-view stereo occlusion sampling deep visual feature(DVF)fusion

Effects of built-in electric field and donor impurity on linear and nonlinear optical properties of wurtzite InxGa1-xN/GaN nanostructures

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8期29卷 479-484页

作者： Xiao-chen Yang Yan xing School of Physical Science and Technology Inner Mongolia UniversityHohhot 010021China

The linear and nonlinear optical absorption coefficients(ACs)and refraction index changes(RICs)of 1s-1p,1p-1d,and 1f-1d transitions are investigated in a wurtzite InxGa1-xN/GaN core-shell quantum dot(CSQD)with donor impurity by using density matrix *** effects of built-in electric field(BEF),ternary mixed crystal(TMC),impurity,and CSQD size are studied in *** finite element method is used to calculate the ground and excited energy state energy and wave *** results reveal that the BEF has a great influence on the linear,nonlinear,and total ACs and *** presence of impurity leads the resonant peaks of the ACs and RICs to be blue-shifted for all transitions,especially for 1s-1p *** is also found that the resonant peaks of the ACs and RICs present a red shift with In-composition decreasing or core radius ***,the amplitudes of the ACs and RICs are strongly affected by the incident optical *** absorption saturation is more sensitive without the impurity than with the impurity,and the appearance of absorption saturation requires a larger incident optical intensity when considering the BEF.

关键词： core-shell quantum dot linear and nonlinear optical properties impurity ternary mixed crystal

Damping of Magnetorheological Elastomers

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2008年第6期21卷 581-585页

作者： Lin chen xing-long Gong Wei-hua Li CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern Me- chanics University of Science and Technology of China Hefei 230027 China School of Mechanical Materials and Mechatronic Engineering University of Wollongong Wollongong NSW 2522 Australia

The damping property of magnetorheological （MR） elastomers is characterized by a modified dynamic mechanical-magnetic coupled analyzer. The influences of the external magnetic flux density, damping of the matrix, content of iron particles, dynamic strain, and driving frequency on the damping properties of MR elastomers were investigated experimentally. The experimental results indicate that the damping properties of MR elastomers greatly depend on the interfacial slipping between the inner particles and the matrix. Different from general composite materials, the interracial slipping in MR elastomers is affected by the external applied magnetic field.

关键词： Magnetorheological elastomers Damping property Interfacial slipping

Superconvergence of Mixed Methods for Optimal Control Problems Governed by Parabolic Equations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2011年第4期3卷 401-419页

作者： Xiaoqing xing Yanping chen School of Mathematical Sciences South China Normal UniversityGuangzhou 510631GuangdongChina

In this paper,we investigate the superconvergence results for optimal control problems governed by parabolic equations with semidiscrete mixed finite element *** use the lowest order mixed finite element spaces to discrete the state and costate variables while use piecewise constant function to discrete the control *** estimates for both the state variable and its gradient variable are obtained.

关键词： Optimal control mixed finite element superconvergence parabolic equations

Configuration Assignment of Superdeformed Bands in Odd-A Hg nuclei

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 journal of nuclear physics 1994年第2期16卷 133-138页

作者： chen, xingqu xing, Zheng Lanzhou Univ Lanzhou China

-By using particle-rotor model,the configuration of the superderformed(SD)bands in odd-A Hg nuclei is *** is shown that the electromagnetic transitionproperties of the SD bands can be used to further identify the conf... 详细信息

关键词： Nuclear structure Superdeformed bands Particle-rotor model Configuration assignment

Nanomaterial Labels in Lateral Flow Immunoassays for Point-of-Care-Testing

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第1期60卷 90-104页

作者： Jiuchuan Guo Shuqin chen Jinhong Guo xing Ma School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 610054China Flexible Printed Electronic Technology Center&School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China Shenzhen Bay Laboratory No.9 Duxue RoadShenzhen 518055China

Lateral flow immunoassays(LFIAs) have been developed rapidly in recent years and used in a wide range of application at point-of-care-testing(POCT),where small biomolecules can be conveniently examined on a test *** with other biochemical detection methods such as ELISA(enzyme linked immunosorbent assay) or mass spectrometry method,LFIAs have the advantages of low cost,easy operation and short ***,it suffers from low sensitivity since conventional LFIA can only realize qualitative detection based on colorimetric *** the increasing demand for more accurate and sensitive determination,novel nanomaterials have been used as labels in LFIAs due to their unique advantages in physical and chemical *** gold,fluorescent nano particles,SERSactive nanomaterials,magnetic nanoparticles and carbon nanomaterials are utilized in LFIAs to produce different kinds of signals for quantitative or semi-quantitative *** review paper first gives a description of the LFIA principles,and then focuses on the state-of-the-art nanomaterial labelling technology in *** last,the conclusion and outlook are given to inspire exploration of more advanced nanomaterials for the development of future LFIAs.

关键词： lateral flow immunoassays(LFIA) point-of-care-testing(POCT) nanomaterial labelling technology quantitative detection