期刊文献+
共找到31篇文章
< 1 2 >
每页显示 20 50 100
耦合mKdV系统的非奇异正子解、负子解及复子解 被引量:4
1
作者 张玲 桑本文 胡恒春 《上海理工大学学报》 CAS 北大核心 2012年第1期76-80,87,共6页
研究从二层流体模型中导出的变系数耦合mKdV模型,利用达布变换法,并依据系统中Lax对的谱参数的性质,给出了耦合mKdV系统的正子解、负子解、复子解及这些解的具体结构图形.其中所得到的耦合mKdV系统的正子解、负子解和复子解都是解析的,... 研究从二层流体模型中导出的变系数耦合mKdV模型,利用达布变换法,并依据系统中Lax对的谱参数的性质,给出了耦合mKdV系统的正子解、负子解、复子解及这些解的具体结构图形.其中所得到的耦合mKdV系统的正子解、负子解和复子解都是解析的,而复子解可看作一种形式的周期波解. 展开更多
关键词 正子解 耦合KdV系统
下载PDF
子午弧长正反解幂级数公式的简单形式
2
作者 王政梅 李晓 高亮 《交通科技》 2002年第1期15-17,共3页
采用幂级数减缩法对一组可算至任意精度的子午弧长正反解幂级数展开式进行减缩 ,得出适用于全球的减缩公式以及适用于我国的减缩公式。减缩式不仅形式简单、使用方便 。
关键词 幂级数公式 午弧长 午弧长反 幂级数减缩法
下载PDF
Initial Value Problem of Singular n-Laplacian Equation
3
作者 王宏洲 葛渭高 《Journal of Beijing Institute of Technology》 EI CAS 2001年第3期225-232,共8页
To show some theorems on the existence of singular initial value problem with n Laplacian operator, topology method and methods of analysis are employed. Some existence theorems for initial value problems... To show some theorems on the existence of singular initial value problem with n Laplacian operator, topology method and methods of analysis are employed. Some existence theorems for initial value problems with n Laplacian operators are established in three singular cases. 展开更多
关键词 initial value problem n Laplacian operator positive solution CONE
下载PDF
Existence of Multiple Positive Solutions for Higher-Order p-Laplacian Boundary Value Problems
4
作者 贺小明 葛渭高 《Journal of Beijing Institute of Technology》 EI CAS 2002年第2期212-216,共5页
The existence of multiple positive solutions for a class of higher order p Laplacian boundary value problem is studied. By means of the Leggett Williams fixed point theorem in cones, existence criteria which e... The existence of multiple positive solutions for a class of higher order p Laplacian boundary value problem is studied. By means of the Leggett Williams fixed point theorem in cones, existence criteria which ensure the existence of at least three positive solutions of the boundary value problem are established. 展开更多
关键词 positive solutions cone Leggett Williams fixed point theorem p Laplacian boundary value problems
下载PDF
Representations and Classification of Traveling Wave Solutions to sinh-Grdon Equation 被引量:4
5
作者 LIU Cheng-Shi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第1期153-158,共6页
Two concepts named atom solution and combinatory solution are defined. The classification of all single traveling wave atom solutions to sinh-Gordon equation is obtained, and qualitative properties of solutions are di... Two concepts named atom solution and combinatory solution are defined. The classification of all single traveling wave atom solutions to sinh-Gordon equation is obtained, and qualitative properties of solutions are discussed. In particular, we point out that some qualitative properties derived intuitively from dynamic system method are not true. Finally, we prove that our solutions to sinh-Gordon equation include all solutions obtained in the paper [Z.T. Fu, et al., Commun. Theor. Phys. (Beijing, China) 45 (2006) 55]. Through an example, we show how to give some new identities on Jacobian elliptic functions. 展开更多
关键词 traveling wave solution atom solution exact solution sinh-GSrdon equation elliptic function
下载PDF
Instantaneous Bethe-Salpeter Equation and Its Exact Solution 被引量:2
6
作者 CHANGChao-Hsi CHENJiao-Kai +1 位作者 LIXue-Qia WANGGuo-Li 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第1期113-118,共6页
We present an approach to solve Bethe-Salpeter (BS) equations exactly withoutany approximation if the kernel of the BS equations exactly is instantaneous, and take positroniumas an example to illustrate the general fe... We present an approach to solve Bethe-Salpeter (BS) equations exactly withoutany approximation if the kernel of the BS equations exactly is instantaneous, and take positroniumas an example to illustrate the general features of the exact solutions. The key step for theapproach is from the BS equations to derive a set of coupled and well-determined integrationequations in linear eigenvalue for the components of the BS wave functions equivalently, which maybe solvable numerically under a controlled accuracy, even though there is no analytic solution. Forpositronium, the exact solutions precisely present corrections to those of the correspondingSchrodinger equation in order υ~1 (υ is the relative velocity) for eigenfunctions, in order υ~2for eigenvalues, and the mixing between S and D components in J~(PC) = 1~(--) states etc.,quantitatively. Moreover, we also point out that there is a questionable step in some existentderivations for the instantaneous BS equations if one is pursuing the exact solutions. Finally, weemphasize that one should take the O(υ) corrections emerging in the exact solutions into accountaccordingly if one is interested in the relativistic corrections for relevant problems to the boundstates. 展开更多
关键词 instantaneous BS equation exact solutions POSITRONIUM relativisticcorrections
下载PDF
Several Properties of p-w-hyponormal Operators 被引量:1
7
作者 LI Hai-ying YANG Chang-sen 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2008年第2期195-201,共7页
In this paper, let T be a bounded linear operator on a complex Hilbert H. We give and prove that every p-w-hyponormal operator has Bishop's property(β) and spectral properties; Quasi-similar p-w-hyponormal operat... In this paper, let T be a bounded linear operator on a complex Hilbert H. We give and prove that every p-w-hyponormal operator has Bishop's property(β) and spectral properties; Quasi-similar p-w-hyponormal operators have equal spectra and equal essential spectra. Finally, for p-w-hyponormal operators, we give a kind of proof of its normality by use of properties of partial isometry. 展开更多
关键词 Aluthge transformation Bishop's property(β) quasi-similar w-hyponormal operators p-w-hyponormal operators
下载PDF
On the Representation of Some Subnormal Operators
8
作者 席俊 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第2期36-40,共5页
Let T be pure subnormal operator. In this paper necessary and sufficiert conditions that T=N+K are given,where N is normal, K is quasinormal and NK=KN.
关键词 subnormal operators self-dual subnormal operators
下载PDF
Positive Solutions of p-Laplacian Functional Difference Equations 被引量:1
9
作者 SONG Chang-xiu 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2007年第4期475-481,共7页
In this paper, the author studies the boundary value problems for a p-Laplacian functional difference equation. By using a fixed point theorem in cones, sufficient conditions are established for the existence of the p... In this paper, the author studies the boundary value problems for a p-Laplacian functional difference equation. By using a fixed point theorem in cones, sufficient conditions are established for the existence of the positive solutions. 展开更多
关键词 p-Laplacian operator functional difference equations positive solution CONE
下载PDF
Aircraft attitude estimation of MEMS sensor based on modified particle filter 被引量:3
10
作者 MA Wen-gang WANG Xiao-peng +1 位作者 ZHANG Yong-fang CHENG Dong-liang 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2018年第2期180-187,共8页
The non-linearity problem of aircraft system could not be overcome by using the MEMS sensor only.In order to improve the accuracy of aerial vehicle attitude,an aircraft attitude estimation of the MEMS sensor based on ... The non-linearity problem of aircraft system could not be overcome by using the MEMS sensor only.In order to improve the accuracy of aerial vehicle attitude,an aircraft attitude estimation of the MEMS sensor based on modified particle filter is proposed.The aircraft attitude is optimized by the conjugate gradient method,and the drift error of gyroscope is reduced.Moreover,the particle weight is updated by the observed value to obtain an optimized state estimate.Finally,the conjugate gradient method and the modified particle filter are weightily combined to determine the optimal weighting factor.The attitude estimation is carried out with STM32 and MEMS sensor as the core to design system.The experimental results show that the static and dynamic attitude estimation performances of the aircraft are improved.The performances are well,the attitude data is relatively stable,and the tracking characteristics are better.Moreover,it has better robustness and stability. 展开更多
关键词 aircraft attitude estimation modified particle filter MEMS sensor conjugate gradient method weighted fusion
下载PDF
Electronic-Positron (Pairino's) Structure of Nuclear Substance (Matter)
11
作者 Chuvilskaya Tatjana Victorovna 《Journal of Physical Science and Application》 2015年第4期283-287,共5页
Decrease or enlargement of the number of pairinos in nuclei and as free nucleons, pairinos, electrinos, positpinos is a factor of destabilization in the matter and or environment. For the benefit of a electronic-posit... Decrease or enlargement of the number of pairinos in nuclei and as free nucleons, pairinos, electrinos, positpinos is a factor of destabilization in the matter and or environment. For the benefit of a electronic-positron structure the representations about an annihilation of the electronic-positron pairs, formation in substance electronic-positron of pairs under activity action of a gamma radiation, electronic and positron character of a beta radiation in nuclei are worked. Terminology: positrino, electrino, pairino. The new mechanism of a physical phenomenon, well explored to the present moment, with the conventional interpretation - mechanism of an annihilation of a free positron on electrons of substance is offered. That is the conventional point of view is those, that during annihilation the electron bums down, disappears or is transmuted into a gamma-quantum. In opinion of the author any facts or the proofs of such interpretation do not exist. The following mechanism therefore is offered: an electron and positron at coming together are discharged by two gamma-quantum and form pairino (unloaded electron - positron state with gravitational mass "m" about 2 eV, with compensation by electric charge, about an electrino by positrino interaction); that is the mechanism "cold" (low, is less than 10 KeV, energies) synthesis of pairino. The given mechanism of phenomenon of annihilation is more realistic. 展开更多
关键词 Positrino electrino pairino.
下载PDF
Optimizing pyrolysis of resin carbon for anode of lithium ion batteries 被引量:1
12
作者 郭华军 李新海 +3 位作者 张新明 王志兴 彭文杰 张宝 《Journal of Central South University of Technology》 EI 2006年第1期58-62,共5页
Pyrolytic resin carbon anode for lithoum ion batteries was prepared from thermosetting phenolic resin. Pyrolysis of the primary phenolic resin and the dewatered one was studied by thermal gravimetric analysis. Structu... Pyrolytic resin carbon anode for lithoum ion batteries was prepared from thermosetting phenolic resin. Pyrolysis of the primary phenolic resin and the dewatered one was studied by thermal gravimetric analysis. Structures and characteristics of the carbon materials were determined by X-ray diffraction, Brunauer-Emmer-Teller surface area analysis and electrochemical measurements. With the increase of pyrolyzing temperature and soaking time, the resin carbon material has larger crystallite sizes of L_c and L_a, lower specific surface area, smaller irreversible capacity and higher initial coulombic efficiency. The pyrolyzing temperature and soaking time are optimized to be 1050℃ and 2h. The resin carbon anode obtained under the optimum conditions shows good electrochemical performances with reversible capacity of 387mA·h/g and initial coulombic efficiency of 69.1%. 展开更多
关键词 lithium ion battery CARBON phenolic resin ANODE
下载PDF
New Multiple Soliton-like and Periodic Solutions for (2+l)-Dimensional Canonical Generalized KP Equation with Variable Coefficients 被引量:3
13
作者 ZHANG Li-Hua LIU Xi-Qiang BAI Cheng-Lin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第5X期793-798,共6页
In this paper, the generalized ranch function method is extended to (2+1)-dimensianal canonical generalized KP (CGKP) equation with variable coetfficients. Taking advantage of the Riccati equation, many explicit ... In this paper, the generalized ranch function method is extended to (2+1)-dimensianal canonical generalized KP (CGKP) equation with variable coetfficients. Taking advantage of the Riccati equation, many explicit exact solutions, which contain multiple soliton-like and periodic solutions, are obtained for the (2+1)-dimensional OGKP equation with variable coetffcients. 展开更多
关键词 (2+1)-dimensional canonical generalized (CGKP) equation with variable coefficients tanh function method Riccati equation soliton-like and periodic solutions
下载PDF
FM Space Depend on Operator T and the Normal Solvability of Operator Polynomial P(T)
14
作者 Han Liubing(Dept. of Appl. Math. Southwest Jiaotong University, Chengdu, 610031 ) 《Chinese Quarterly Journal of Mathematics》 CSCD 1996年第1期78-81,共4页
In this paper,generalized the ideas of theory of distributions,defined locally convex space depend on operator T,given a new method to change the study of a unbounded operator to a bounded operator, and proved the nor... In this paper,generalized the ideas of theory of distributions,defined locally convex space depend on operator T,given a new method to change the study of a unbounded operator to a bounded operator, and proved the normal solvability of operator polynomial P (T) on FM space that depend on operator T. 展开更多
关键词 FM space:operator T
下载PDF
A Note on Generalized Aluthge Transformation for p-hyponormal and Log-hyponormal Operators
15
作者 DAI Hui-ya YANG Chang-sen 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2008年第4期525-532,共8页
We shall give some results on generalized aluthge transformation for phyponormal and log-hyponormal operators. We shall also discuss the best possibility of these results.
关键词 positive operator Furuta inequality Aluthge transformation best possibility
下载PDF
New Explicit Exact Solutions for the (2+1)-Dimensional Higher-Order Broer-Kaup System
16
作者 BAICheng-Lin ZHAOHong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第4期521-526,共6页
Using the modified extended tanh-function method,explicit and exact traveling wave solutions for the(2+1)-dimensional higher-order Broer-Kaup(HBK)system,comprising new soliton-like and period-form solutions,are obtained.
关键词 modified extended tanh-function method (2+1)-dimensional HBK system soliton-like solutions period-form solutions
下载PDF
Shocks and Solitons in Ultradense Degenerate Electron-Positron-Ion Plasmas
17
作者 S.A.Khan Arshad M.Mirza 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第1期151-157,共7页
The formation and propagation of shocks and solitons are investigated in an unmagnetized, ultradense plasma containing degenerate Fermi gas of electrons and positrons, and classical ion gas by employing Thomas-Fermi m... The formation and propagation of shocks and solitons are investigated in an unmagnetized, ultradense plasma containing degenerate Fermi gas of electrons and positrons, and classical ion gas by employing Thomas-Fermi model. For this purpose, a deformed Korteweg-de Vries-Berger (dKdVB) equation is derived using the reductive perturbative technique for cold, adiabatic, and isothermal ions. Localized analytical solutions of dKdVB equation in planar geometry are obtained for dispersion as well as dissipation dominant cases. For nonplanar (cylindrical and spherical) geometry, time varying numerical shock wave solution of dKdVB equation is found. Its dispersion dominant case leading to the soliton solution is also discussed. The effect of ion temperature, positron concentration and dissipation is found significant on these nonlinear structures. The relevance of the results to the systems of scientific interest is pointed out. 展开更多
关键词 degenerate plasma nonplanar geometry SHOCKS SOLITONS
下载PDF
Synthesis of ITQ-2 Zeolites and Catalytic Performance in n-Dodecane Cracking
18
作者 郝江鸽 王莹 +3 位作者 刘国柱 张靖雯 李国柱 马雪松 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第8期869-874,共6页
ITQ-2 zeolites were prepared by sequential alkali-swelling and ultrasonic-delamination of precursor MCM-22 and characterized by X-ray powder diffraction, scanning electron microscopy, nitrogen adsorption-desorption, a... ITQ-2 zeolites were prepared by sequential alkali-swelling and ultrasonic-delamination of precursor MCM-22 and characterized by X-ray powder diffraction, scanning electron microscopy, nitrogen adsorption-desorption, ammonia temperature-programmed desorption and in-situ Fourier-transform infrared spectroscopy. The delamination induced a change in the morphology of ITQ-2 zeolites from aggregated thin platelets to scattered platelets, together with a significant increase in external specific surface area, which reached a plateau at the ultrasonic treatment time of 3 h. The catalytic cracking of n-dodecane over ITQ-2 zeolites was evaluated with ITQ-2 coated on the inside wall of a tubular reactor at 550 ℃ and 4 MPa. The sample obtained by ultrasonic treatment of 3 h (ITQ-2-3) gave the highest initial conversion of n-dodecane, whereas those of 5 h and I h gave the conversion even lower than MCM-22, which was in agreement with the trend of the ratio of strong Lewis acid to the total acid amount. Although the amount of cokes deposited on ITQ-2-3 was larger than that on MCM-22, the former deactivated slowly, suggesting that a large external specific surface area benefits the stability of zeolite coatings, 展开更多
关键词 MCM-22 zeolite ITQ-2 zeolite SWELLING DELAMINATION Catalytic cracking N-DODECANE
下载PDF
Significant contributions of the petroleum industry to volatile organic compounds and ozone pollution:Insights from year-long observations in the Yellow River Delta
19
作者 Jinghao Tang Hengqing Shen +7 位作者 Hong Li Yuanyuan Ji Xuelian Zhong Min Zhao Yuhong Liu Mingzhi Guo Fanyi Shang Likun Xue 《Atmospheric and Oceanic Science Letters》 2024年第6期39-44,共6页
The petroleum industry is a significant source of anthropogenic volatile organic compounds(VOCs),but up to now,its exact impact on urban VOCs and ozone(O_(3))remains unclear.This study conducted year-long VOC ob-serva... The petroleum industry is a significant source of anthropogenic volatile organic compounds(VOCs),but up to now,its exact impact on urban VOCs and ozone(O_(3))remains unclear.This study conducted year-long VOC ob-servations in Dongying,China,a petroleum industrial region.The VOCs from the petroleum industry(oil and gas volatilization and petrochemical production)were identified by employing the positive matrix factorization model,and their contribution to O_(3) formation was quantitatively evaluated using an observation-based chemical box model.The observed annual average concentration of VOCs was 68.6±63.5 ppbv,with a maximum daily av-erage of 335.3 ppbv.The petroleum industry accounted for 66.5%of total VOCs,contributing 54.9%from oil and gas evaporation and 11.6%from petrochemical production.Model results indicated that VOCs from the petroleum industry contributed to 31%of net O_(3) production,with 21.3%and 34.2%contributions to HO_(2)+NO and RO_(2)+NO pathways,respectively.The larger impact on the RO_(2) pathway is primarily due to the fact that OH+VOCs ac-count for 86.9%of the primary source of RO_(2).This study highlights the critical role of controlling VOCs from the petroleum industry in urban O_(3) pollution,especially those from previously overlooked low-reactivity alkanes. 展开更多
关键词 Petroleum industry Volatile organic compounds Ozone pollution Positive matrix factorization Observation-based model
下载PDF
Multiple Positive Solutions to a Nonlinear Two-point Boundary Value Problem with p-Laplacian 被引量:4
20
作者 李志艳 严树林 葛渭高 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2006年第3期480-488,共9页
By a simple application of a new three functionals fixed point theorem, sufficient conditions axe obtained to guarantee the existence of at least three positive solutions for p-Laplacian equation: (φp(u′))′ +... By a simple application of a new three functionals fixed point theorem, sufficient conditions axe obtained to guarantee the existence of at least three positive solutions for p-Laplacian equation: (φp(u′))′ + α(t)f(t,u(t)) = 0 subject to nonlinear boundary value conditions. An example is presented to illustrate the theory. 展开更多
关键词 boundary value problem p-Laplacian operator positive solution the threefunctionals fixed point theorem.
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部