|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | 基于dq锁相环的改进型光伏电站并网点电压跌落检测方法研究显示文摘快速准确检测出并网点电压不同类型的跌落故障是光伏电站实现低电压穿越的前提。针对电压负序分量导致基于dq锁相环的常规检测方法无法检测电压不对称跌落的问题,采用二阶广义积分法对电压进行相序分离,滤除负序分量让正序分量进入锁相环,实现对电压不对称跌落故障的检测。基于Matlab/Simulink搭建了仿真平台,仿真结果表明上述方法对多种类型的电压跌落故障有较高检测精度,验证了该方法的可行性。 | 罗劲松 王金梅 张小娥 | 2014 | 电测与仪表2014，51，5： | 15 |
| 2 | Orbital angular momentum of the laser beam and the second order intensity moments显示文摘From the wave equation of a generalized beam the orbital angular momentum is studied. It is shown that the orbital angular momentum exists not only in the Laguerre-Gaussian beam, but in any beam with an angular-dependent structure. By calculating the second order intensity moments of the beam the relation between the orbital angular momentum and the second order moments 〈xθy〉, 〈yθx〉 is given. As an example the orbital angular momentum of the general astigmatic Gaussian beam is studied. | 高春清 魏光辉 HorstWeber | 2000 | Science China Mathematics2000，43，12： | 6 |
| 3 | THE SINGULAR SECOND ORDER NONLINEAR EIGENVALUE PROBLEM WITH INFINITELY MANY POSITIVE SOLUTIONS显示文摘In this paper we consider the existence of infinitely many positive solutions for second order nonlinear eigenvalue problem with singular coefficient function. By the use of Krasnosel’skii fixed point theorem of cone expansion-compression type we give several sufficient conditions. | 姚庆六 | 2001 | Annals of Differential Equations2001，17，3： | 6 |
| 4 | Analysis of chaos behaviors of a bistable piezoelectric cantilever power generation system by the second-order Melnikov function显示文摘By applying the second order Melnikov function,the chaos behaviors of a bistable piezoelectric cantilever power generation system are analyzed. Firstly, the conditions for emerging chaos of the system are derived by the second order Melnikov function. Secondly, the effects of each item in chaos threshold expression are analyzed. The excitation frequency and resistance values, which have the most influence on chaos threshold value, are found. The result from the second order Melnikov function is more accurate compared with that from the first order Melnikov function. Finally, the attraction basins of large amplitude motions under different exciting frequency, exciting amplitude, and resistance parameters are given. | Shu Sun Shu-Qian Cao | 2017 | Acta Mechanica Sinica2017，33，1： | 5 |
| 5 | INTEGRABILITY OF SECOND ORDER AUTONOMOUS SYSTEM显示文摘The Liouville’s integrability of the second order autonomous system is studied. It isproved that a second order polynomial system is Liouville integrable if and only if thereis an integral factor μ(x, y), such that or a rational function in x and y. | 管克英 雷锦志 | 2002 | Annals of Differential Equations2002，18，2： | 5 |
| 6 | Process mineralogy as a key factor affecting the flotation kinetics of copper sulfide minerals显示文摘The aim of this study is to apply process mineralogy as a practical tool for further understanding and predicting the flotation kinetics of the copper sulfide minerals. The minerals' composition and association, grain distribution, and liberation within the ore samples were analyzed in the feed, concentrate, and the tailings of the flotation processes with two pulp densities of 25 wt% and 30 wt%. The major copper-bearing minerals identified by microscopic analysis of the concentrate samples included chalcopyrite(56.2 wt%), chalcocite(29.1 wt%),covellite(6.4 wt%), and bornite(4.7 wt%). Pyrite was the main sulfide gangue mineral(3.6 wt%) in the concentrates. A 95% degree of liberation with d_(80) > 80 μm was obtained for chalcopyrite as the main copper mineral in the ore sample. The recovery rate and the grade in the concentrates were enhanced with increasing chalcopyrite particle size. Chalcopyrite particles with a d_(80) of approximately 100 μm were recovered at the early stages of the flotation process. The kinetic studies showed that the kinetic second-order rectangular distribution model perfectly fit the flotation test data. Characterization of the kinetic parameters indicated that the optimum granulation distribution range for achieving a maximum flotation rate for chalcopyrite particles was between the sizes 50 and 55 μm. | Ataallah Bahrami Mirsaleh Mirmohammadi Yousef Ghorbani Fatemeh Kazemi Morteza Abdollahi Abolfazl Danesh | 2019 | International Journal of Minerals,Metallurgy and Materials2019，26，4： | 4 |
| 7 | HIGH ACCURACY FINITE VOLUME ELEMENT METHOD FOR TWO-POINT BOUNDARY VALUE PROBLEM OF SECOND ORDER ORDINARY DIFFERENTIAL EQUATIONS显示文摘In this paper, a high accuracy finite volume element method is presented for two-point boundary value problem of second order ordinary differential equation, which differs from the high order generalized difference methods. It is proved that the method has optimal order error estimate O(h3) in H1 norm. Finally, two examples show that the method is effective. | Wang Tongke(王同科) | 2002 | Numerical Mathematics A Journal of Chinese Universities(English Series)2002，11，2： | 4 |
| 8 | Error estimate of the homogenization solution for elliptic problems with small periodic coefficients on L~∞(Ω)显示文摘In this paper,we discuss the multi-scale homogenization theory for the second order elliptic problems with small periodic coefficients of the form xi(aij(xε) uεx(jx)) = f(x).Assuming n = 2 and u0 ∈ W 1,∞(Ω),we present an error estimate between the homogenization solution u0(x) and the exact solution uε(x) on the Sobolev space L∞(Ω). | HE WenMing1,2 & CUI JunZhi3 1Department of Mathematics,Wenzhou University,Wenzhou 325035,China 2School of Aeronautics and Astronautics,Zhejiang University,Hangzhou 310027,China 3LSEC,ICMSEC,Academy of Mathematics and Systems Science,Chinese Academy of Sciences,Beijing 100190,China | 2010 | Science China Mathematics2010，53，5： | 4 |
| 9 | A Second Main Theorem on P^n for difference operator显示文摘The main result of this article is an extension of the Second Main Theorem,of Halburd and Korhonen,for meromorphic functions of finite order.Their result replaces the counting function of the ramification divisor Nramf(r)in the classical Second Main Theorem by the counting function of a finite difference divisor Npair(r).In this article,the Second Main Theorem of Halburd and Korhonen is extended to the case of holomorphic maps into Pn of finite order. | WONG Pit-Mann LAW Hiu-Fai WONG Philip P.W. | 2009 | Science China Mathematics2009，52，12： | 2 |
| 10 | METHOD OF NONCONFORMING MIXED FINITE ELEMENTFOR SECOND ORDER ELLIPTIC PROBLEMSMETHOD OF NONCONFORMING MIXED FINITE ELEMENTFOR SECOND ORDER ELLIPTIC PROBLEM显示文摘In this paper, the method of non-conforming mixed finite element for second order elliptic problems is discussed and a format of real optimal order for the lowest order error estimate. | Zhen-dong Luo (Department of Mathematics, Capital Normal University, Beijing 100057, China) | 2000 | Journal of Computational Mathematics2000，18，5： | 2 |
| 11 | Spectral analysis and numerical simulation for second order elliptic operator with highly oscillating coefficients in perforated domains with a periodic structure显示文摘This paper discusses the spectral properties and numerical simulation for the second order elliptic operators with rapidly oscillating coefficients in the domains which may contain small cavities distributed periodically with period ε. A multiscale asymptotic analysis formula for this problem is obtained by constructing properly the boundary layer. Finally, numerical results are given, which provide a strong support for the analytical estimates. | 曹礼群 崔俊芝 诸德超 罗剑兰 | 2002 | Science China Mathematics2002，45，12： | 2 |
| 12 | Second Order Sliding Mode Control for Discrete Decouplable Multivariable Systems via Input-output Models显示文摘The problem of the chattering phenomenon is still the main drawback of the classical sliding mode control. To resolve this problem, a discrete second order sliding mode control via input-output model is proposed in this paper. The proposed control law is synthesized for decouplable multivariable systems. A robustness analysis of the proposed discrete second order sliding mode control is carried out. Simulation results are presented to illustrate the effectiveness of the proposed strategy. | Houda Romdhane Khadija Dehri Ahmed Said Nouri | 2015 | International Journal of Automation and computing2015，12，6： | 2 |
| 13 | OSCILLATION THEOREMS FOR A CLASS OF TWO-DIMENSIONAL DELAY DIFFERENTIAL SYSTEMS显示文摘By Riccati transformation, we establish some oscillation theorems for a class of two-dimensional nonlinear delay differential systems. The results obtained generalize some relatively known results. | Jinchang Yu | 2013 | Annals of Differential Equations2013，29，1： | 2 |
| 14 | Maximal regularity of second order delay equations in Banach spaces显示文摘We give necessary and sufficient conditions of Lp-maximal regularity(resp.B sp ,q-maximal regularity or F sp ,q-maximal regularity) for the second order delay equations:u″(t)=Au(t) + Gu't + F u t + f(t), t ∈ [0, 2π] with periodic boundary conditions u(0)=u(2π), u′(0)=u′(2π), where A is a closed operator in a Banach space X,F and G are delay operators on Lp([-2π, 0];X)(resp.Bsp ,q([2π, 0];X) or Fsp,q([-2π, 0;X])). | BU ShangQuan ? & FANG Yi Department of Mathematical Sciences, Tsinghua University, Beijing 100084, China Department of Mathematical Sciences, Tsinghua University, Beijing 100084, China | 2010 | Science China Mathematics2010，53，1： | 2 |
| 15 | PERIODIC BOUNDARY VALUE PROBLEMS FOR A SECOND ORDER IMPLICIT DIFFERENTIAL EQUATION显示文摘In this paper we describe a constructive method which yields two monotone sequences that converge uniformly to extremal solutions to the periodic boundary value problem in the presence of an upper solution βand lower solution a with β a. | 刘辉昭 赵宏亮 赵胜民 | 1999 | Annals of Differential Equations1999，15，2： | 2 |
| 16 | A Theoretical Study of Nonlinear Second-Order Optical Properties of Substituted Silanes显示文摘ATheoreticalStudyofNonlinearSecond┐OrderOpticalPropertiesofSubstitutedSilanes*SupportedbytheNationalNaturalScienceFoundationo... | FENG Ji kang, WANG Hai chuan, WEI Jia you, XIAO Chang yong XU Wen guo and SUN Chia chung (Department of Chemistry and Institute of Theoretical Chemistry, Jilin University, Changchun, 130023) | 1997 | Chemical Research in Chinese Universities1997，13，1： | 1 |
| 17 | A SECOND ORDER STATIONARY SOLUTION OF THE THREE DIMENSIONAL WAVE DIFFRACTION POTENTIAL显示文摘A theory on the second order wave diffraction by a three dimensional body fixed in a regular seahas been developed in the present paper. By regarding the sinusoidal disturb potential as a stationary solu-tion of an initial value problem, and using Laplace transformation method and Tauberian theorem, theboundary value problems of stationary solution of the first and second order diffraction potential have been de-rived in this paper. Furthermore, the explicit solution of the second order stationary diffraction potential hasbeen obtained with the method of the double Fourier transformation. It is found that the asymptoticbehaviour of the second order stationary solution at far field is dependent on two wave systems, the first is'free wave', travelling independently of the first order wave system, the other is 'phase locked waves',which accompany the first order waves. At the same time, the radiation conditions of the second orderdiffraction problems are derived. We also find that one can still pursue a steady state formulation with theinclusion of Rayleigh damping. Finally, as an example, the second order wave forces upon a fixed vertical cir-cular cylinder have been calculated, and the numerical results agree well with the experimental data. | | 1991 | Acta Mechanica Sinica1991，7，1： | 1 |
| 18 | OSCILLATION CRITERIA FOR SECOND ORDER NONLINEAR NEUTRAL PERTURBED DYNAMIC EQUATIONS ON TIME SCALES显示文摘In this paper,we discuss the oscillatory behavior of a class of nonlinear neutral perturbed dynamic equations on time scales.Some new oscillation criteria are obtained for such dynamic equations.Finally,an example that dwells upon the sharp conditions of our result is also included. | Xiuping Yu 1,Hongyu Yang 2,Jianmei Zhang 1,Chengmin Hou 3 1.Dept.of Math.and Physics,Hebei Institute of Architecture and Civil Engineering,Zhangjiakou 075024,Hebei 2.Dept.of Mechanic and Engineering,Zhangjiakou Vocational Technology Institute,Zhangjiakou 075031,Hebei 3.Dept.of Math.,Yanbian University,Yanji 133002,Jilin, | 2012 | Annals of Differential Equations2012，28，4： | 1 |
| 19 | Effects of Second Order Scattered Wave in Stratified Ocean显示文摘By using the theories on Stokes multicolored water waves and taking the two- layer ocean as a basic model of stratified ocean, the paper analyzes the problems related to the effects of the nonlinear water wave on offshore structures. A mathematical expression is presented to describe second order wave radiation conditions. Using integral principle, the analytical integral solutions are given to evaluate second order scattered wave loads on general vertical circular cylinders in the two-layer ocean, and the special recurrence formulas for infinite integrals over free and stratified surfaces are derived. | 黄华 詹杰民 朱顶金 廖德驹 | 2001 | Marine Science Bulletin2001，3，1： | 1 |
| 20 | PREPARATION AND SECOND-ORDER OPTICAL NONLINEARITY OF NOVEL PHENOXYSILICON NETWORKS BY SOL-GEL PROCESS显示文摘Four phenoxysilicon networks for nonlinear optical (NLO) applications were designed and prepared by an extended sol-gel process without additional H20 and catalyst. All poled polymer network films possess high second-order nonlinear optical coefficients (d33) of 10-?~10-8 esu. The investigation of NLO temporal stability at room temperature and elevated temperature (120°C) indicated that these films exhibit high d33 stability because the orientation of the chromophores are locked in the phenoxysilicon organic/inorganic networks. | Xiao Huang Jian Wang Ling-zhi Zhang Zhi-gang Cai Zhao-xi Lianga | 2001 | Chinese Journal of Polymer Science2001，19，1： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员