检索结果-南通市图书馆

On a Criterion of Universal Spectra

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2013年第7期29卷 1323-1328页

作者： jian lin LI College of Mathematics and Information Science Shaanxi Normal University

For positive integers N1,N2,...,Nn, let L = Z^n ＋ A and A =- N1Z x -…… x NnZ ＋ F be two rational periodic sets, where A ∩ （1/N1）Z x ... x （1/Nn）Z and F ∩ Z^n are finite sets with （A- A）∩Z^n = {0} and （F- F）N （N1Z x.. x NnZ） = {0}. In this note, we shall determine conditions under which the tiling set L has universal spectrum A. We first obtain a criterion of universal spectra. This criterion combined with the properties of compatible pair yields many necessary and sufficient conditions for A to be a universal spectrum for L. We then show that, under some mild additional conditions, the conjecture of Lagarias and Szab5 is true. The results here extend the corresponding results of Lagarias, Szabo and Wang.

关键词： Spectral set periodic set tiling universal spectrum

Distance Sets Relating to Orthogonal Exponentials

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2011年第12期27卷 2409-2414页

作者： jian lin LI College of Mathematics and Information Science Shaanxi Normal University Xi＇an 710062 P. R. China

The aim of this paper is to investigate the size properties of a planar set whose distance set has some prescribed arithmetic combinatorics. Such research is motivated by the conjecture that the disk has no more than 3 orthogonal exponentials. By proving a shifted version of ErdSs-Solymosi＇s theorem on the distance sets, we give some grounds on the conjecture. The results obtained here extend the corresponding results of Iosevich and Jaming in a simple manner.

关键词： Distance sets orthogonal exponentials convex sets algebraic number and transcendental number

Rh single atom catalyst for direct conversion of methane to oxygenates

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

Science China Materials 2018年第5期61卷 758-760页

作者： jian lin Xiaodong Wang State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences

Along with the fast development of economy and growthof world＇s population, the demand for energy is sig-nificantly enhanced. The conventional petroleum andcoal resources are unrenewable and bring about severepollution to the environment. In the past decade, thetechnological advances in drilling and exploitation lead toa significant increase in the production capacity of shalegas worldwide.

关键词：中国科学材料科学

Support vector classification algorithm based on variable parameter linear programming

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2007年第2期18卷 355-359页

作者： Xiao jianhua lin jian Systems Science and Technology Inst. Wuyi Univ. Jiangmen 529020 P. R. China School of Economy and Management Beijing Univ. of Aeronautics and Astronautics Beijing 100083 P. R. China

To solve the problems of SVM in dealing with large sample size and asymmetric distributed samples, a support vector classification algorithm based on variable parameter linear programming is proposed. In the proposed algorithm, linear programming is employed to solve the optimization problem of classification to decrease the computation time and to reduce its complexity when compared with the original model. The adjusted punishment parameter greatly reduced the classification error resulting from asymmetric distributed samples and the detailed procedure of the proposed algorithm is given. An experiment is conducted to verify whether the proposed algorithm is suitable for asymmetric distributed samples.

关键词： Support vector machine linear programming Classification Variable parameter.

A unified analysis of a micro-beam,droplet and CNT ring adhered on a substrate:Calculation of variation with movable boundaries

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2013年第1期29卷 62-72页

作者： jian-lin Liu Re Xia School of Pipeline and Civil Engineering China University of Petroleum School of Power and Mechanical Engineering Wuhan University

In this study, we developed a general method to analytically tackle a kind of movable boundary problem from the viewpoint of energy variation. Having grouped the adhesion of a micro-beam, droplet and carbon nanotube （CNT） ring on a substrate into one framework, we used the developed line of reasoning to investigate the adhesion behaviors of these systems. Based upon the derived governing equations and transversality conditions, explicit solutions involving the critical parameters and morphologies for the three systems are successfully obtained, and then the parameter analogies and common characteristics of them are thor- oughly investigated. The presented method has been verified via the concept of energy release rate in fracture mechanics. Our analyses provide a new approach for exploring the mechanism of different systems with similarities as well as for understanding the unity of nature. The analysis results may be beneficial for the design of nano-structured materi- als, and hold potential for enhancing their mechanical, chemical, optical and electronic properties.

关键词： Variational theory - Transversality condition Beam adhesion Droplet adhesion Carbon nanotube ring adhesion

Effects of compressibility on the Rayleigh-Taylor instability in Z-pinch implosions

在线全文

学校读者我要写书评

暂无评论

核聚变与等离子体物理 2006年第2期26卷 87-94页

作者： HUANG lin jian Guang-de Southwestern Institute of Physics Chengdu 61004 1

The effects of compressibility on the Rayleigh-Taylor instability in Z-pinch implosion plasmas are investigated by means of simple slab *** linear mode equation,which includes main steady-state quantities and their gradients,is *** solutions are *** incompressible fluid result is also *** results indicate that the linear growth rate of the Rayleigh-Taylor instability for the compressible magnetohydrodynamic fluid is far larger than one in the incompressible ***,the compressible systems are all more unstable than the incompressible ones.

关键词： Z-pinch Rayleigh-Taylor instability Compressibility Growth rate.

A PROJECTION-TYPE METHOD FOR SOLVING VARIOUS WEBER PROBLEMS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2006年第4期24卷 527-538页

作者： jian-lin jiang Bo Chen Department of Mathematics Nanjing University Nanjing 210093 China

This paper investigates various Weber problems including unconstrained Weber problems and constrained Weber problems under l1, l2 and l∞-norms. First with a transformation technique various Weber problems are turned into a class of monotone linear variational inequalities. By exploiting the favorable structure of these variational inequalities, we present a new projection-type method for them. Compared with some other projection-type methods which can solve monotone linear variational inequality, this new projection-type method is simple in numerical implementations and more efficient for solving this class of problems; Compared with some popular methods for solving unconstrained Weber problem and constrained Weber problem, a singularity would not happen in this new method and it is more reliable by using this new method to solve various Weber problems.

关键词： linear variational inequality Various Weber problems Projection-type method Slack technique.

Low-temperature conversion of methane to oxygenates by supported metal catalysts: From nanoparticles to single atoms

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 Journal of Chemical Engineering 2021年第10期34卷 18-29页

作者： Geqian Fang jian lin Xiaodong Wang CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China

Direct cost-effective conversion of abundant methane to high value-added oxygenates(methanol,formic acid,acetic acid,etc.)under mild conditions is prospective for optimizing the structure of energy ***,the CAH bond of products is more reactive than that of high thermodynamic stable *** an appropriate approach to eliminate the‘‘seesaw effect"between methane conversion and oxygenate selectivity is *** this review,we briefly summarize the research progress in the past decade on low-temperature direct conversion of methane to oxygenates in gas-solid-liquid phase over various transition metal(Fe,Cu,Rh,Pd,Au Pd,etc.)based nanoparticle or single-atom ***,the prospects of catalyst design and catalysis process are also discussed.

关键词： Methane Oxygenates Supported metal catalysts Nanoparticle Single-atom catalysts

Recent progress in self-propelled particles

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第1期36卷 61-77页

作者： Zhen-yu Ouyang jian-zhong lin Laboratory of Impact and Safety Engineering Ministry of EducationNingbo UniversityNingbo315201China Department of Mechanics State Key Laboratory of Fluid Power and Mechatronic SystemsZhejiang UniversityHangzhou310027China

Self-propelled particles are commonly found in a large number of planktonic organisms such as bacteria,fungi,and algae in nature,and researchers have taken a long interest in exploring their swimming mechanisms for more than a *** in the past 20 years,with the development of computational fluid dynamics and flow display technology,as well as the need for the design of synthetic self-propelled particles and micro-swimming devices,self-propelled particles have become the forefront and hotspot of current research in the field of fluid *** paper first introduces the swimming characteristics of common self-propelled particles,leading to a classic“squirmer”type self-propelled particle *** this basis,a systematic introduction and summary of the theoretical and numerical simulation research of“squirmer”will be ***,the main challenges and opportunities faced by the current research will be summarized.

关键词： Self-propelled particles multiphase flow hydrodynamic interaction