期刊文献+
共找到448篇文章
< 1 2 23 >
每页显示 20 50 100
Research on the completeness of earthquake data in the Chinese mainland(I)──North China
1
作者 黄玮琼 李文香 曹学锋 《Acta Seismologica Sinica(English Edition)》 CSCD 1994年第3期351-359,共9页
In terms of the temporal-spatial distribution features of earthquakes, we study the completeness of historical data in North China where there is the most plenty historical data and with the longest record history by ... In terms of the temporal-spatial distribution features of earthquakes, we study the completeness of historical data in North China where there is the most plenty historical data and with the longest record history by some meth ods of analysis and comparison. The results are obtained for events with Ms≥4 are largely complete since 1484 in North China (except Huanghai sea region and remote districts, such as Nei Mongol Autonomous region), but quakes with Ms≥6 are largely complete since 1291 in the middle and lower reaches of the Yellow River. 展开更多
关键词 completeNESS earthquake data record capability mean annual rate proportionality factor
下载PDF
A New Kind of k-Quantum Nonlinear Coherent States: Their Generation and PhysicalMeaning
2
作者 WANGJi-Suo LIUTang-Kun +2 位作者 FENGJian SUNJin-Zuo ZHANMing-Sheng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第6期935-940,共6页
A new kind of k-quantum nonlinear coherent states,i.e.,the k eigenstates of the k-th power~k (k≥3) of the generalized annihilation operator=1/f() of f-oscillators,are obtained and their properties are discussed.The c... A new kind of k-quantum nonlinear coherent states,i.e.,the k eigenstates of the k-th power~k (k≥3) of the generalized annihilation operator=1/f() of f-oscillators,are obtained and their properties are discussed.The completeness of the k states is investigated.An alternative method to construct them is proposed.It is shown that these states may form a complete Hilbert space,and all of them can be generated by a linear superposition of k Roy-type nonlinear coherent states.Physically,they can be generated by a linear superposition of the time-dependent Roy-type nonlinear coherent states at different instants. 展开更多
关键词 orthonormalized eigenstate k-quantum nonlinear coherent states completeNESS physical meaning
下载PDF
Sharp power-type Heronian and Lehmer means inequalities for the complete elliptic integrals
3
作者 ZHAO Tie-hong CHU Yu-ming 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第3期467-474,共8页
In the article,we prove that the inequalities H_(p)(K(r);E(r))>π/2;L_(q)(K(r);E(r))>π/2 hold for all r 2(0;1)if and only if p≥3=4 and q≥3=4,where Hp(a;b)and Lq(a;b)are respectively the p-th power-type Heroni... In the article,we prove that the inequalities H_(p)(K(r);E(r))>π/2;L_(q)(K(r);E(r))>π/2 hold for all r 2(0;1)if and only if p≥3=4 and q≥3=4,where Hp(a;b)and Lq(a;b)are respectively the p-th power-type Heronian mean and q-th Lehmer mean of a and b,and K(r)and E(r)are respectively the complete elliptic integrals of the first and second kinds. 展开更多
关键词 power-type Heronian mean Lehmer means complete elliptic integrals
下载PDF
On the Mean Value of High-Powers of a Special Character Sum Modulo a Prime
4
作者 Xiaodan Yuan Wenpeng Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第7期943-953,共11页
In this paper,we use the elementary methods,the properties of Dirichlet character sums and the classical Gauss sums to study the estimation of the mean value of high-powers for a special character sum modulo a prime,a... In this paper,we use the elementary methods,the properties of Dirichlet character sums and the classical Gauss sums to study the estimation of the mean value of high-powers for a special character sum modulo a prime,and derive an exact computational formula.It can be conveniently programmed by the“Mathematica”software,by which we can get the exact results easily. 展开更多
关键词 Quadratic character the classical gauss sums the mean value of high-power computational formula
下载PDF
Written Treasures of the Mawangdui Han Tomb
5
《China & The World Cultural Exchange》 1993年第3期24-25,共2页
BEFORE paper-makingwas invented in China,bamboo or wooden slipsand silk were used for writtenmaterials.The following an-cient writings were all doneon bamboo slips:documentsunearthed in the Chu tombs inBaoshan in Hube... BEFORE paper-makingwas invented in China,bamboo or wooden slipsand silk were used for writtenmaterials.The following an-cient writings were all doneon bamboo slips:documentsunearthed in the Chu tombs inBaoshan in Hubei Province;Artof War by Sunzi,a famousChinese classic about militarystrategy and tactics,unearthedin the Han tombs in Yinques- 展开更多
关键词 bamboo classic HUBEI CEREMONY woven ancient SUGGESTION completed seldom CIRCLES
下载PDF
Study on Microsatellite Distribution in Complete Genomes of Tobacco Vein Clearing Virus 被引量:7
6
作者 杨纪青 《Agricultural Science & Technology》 CAS 2010年第7期132-135,共4页
MATLAB software and optimal complete subgraph algorithm were used to extract and reveal the microsatellite distribution features in the complete genomes of the tobacco vein clearing virus (NC-003 378.1) from the NCB... MATLAB software and optimal complete subgraph algorithm were used to extract and reveal the microsatellite distribution features in the complete genomes of the tobacco vein clearing virus (NC-003 378.1) from the NCBI database.The results showed that the repetitions number and their location of the N-base group has been extracted and displayed.The largest repetitions of N-base group in the complete genomes of the tobacco vein clearing virus was decreased as the exponential function with the increasing of N.The method used in this study could be applied to the extraction and revealing of the microsatellite distribution features in the complete genomes of other viruses,thereby provided a basis for the research of the structure and the law of function,inheritance and variation by the using of the microsatellite distribution features. 展开更多
关键词 Tobacco vein clearing virus complete genomes Microsatellite distribution Means of genetic algorithms Optimal complete subgraph algorithm
下载PDF
Quantum Corrections on Relativistic Mean Field Theory for Nuclear Matter 被引量:1
7
作者 张启仁 高春媛 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第5期765-770,共6页
We propose a quantization procedure for the nucleon-scMar meson system, in which an arbitrary mean scalar meson field Ф is introduced. The equivalence of this procedure with the usual one is proven for any given valu... We propose a quantization procedure for the nucleon-scMar meson system, in which an arbitrary mean scalar meson field Ф is introduced. The equivalence of this procedure with the usual one is proven for any given value of qS. By use of this procedure, the scalar meson field in the Walecka's MFA and in Chin's RHA are quantized around the mean field, Its corrections on these theories are considered by perturbation up to the second order. The arbitrariness of Ф makes us free to fix it at any stage in the calculation. When we fix it in the way of Walecka's MFA, the quantum corrections are big, and the result does not converge. When we fix it in the way of Chin's RHA, the quantum correction is negligibly small, and the convergence is excellent. It shows that RHA covers the leading part of quantum field theory for nuclear systems and is an excellent zeroth order approximation for further quantum corrections, while the Walecka's MFA does not. We suggest to fix the parameter Ф at the end of the whole calculation by minimizing the total energy per-nucleon for the nuclear matter or the total energy for the finite nucleus, to make the quantized relativistic mean field theory (QRMFT) a variational method. 展开更多
关键词 relativistic mean field theory quantum corrections quantization around a classical value
下载PDF
Elementary Introduction to the differences in Vocabulary between British English and American English
8
作者 姚金玲 《辽宁省交通高等专科学校学报》 2001年第2期39-40,,36,,共3页
With the development of the two countries, the differences in some fields are clear and are also reflected in their languages. This paper discusses the differences in vocabulary between British English and American En... With the development of the two countries, the differences in some fields are clear and are also reflected in their languages. This paper discusses the differences in vocabulary between British English and American English through three aspects - - - the same words but different meaning, the same meanings but different words,characteistic words. 展开更多
关键词 英语 词义 词汇 多义词 语言表达
下载PDF
The Hybrid Power Mean Involving the Character Sum of Polynomials and a Sum Analogous to Kloosterman Sum
9
作者 LU Xingxing ZHANG Wenpeng 《数学进展》 CSCD 北大核心 2024年第6期1199-1209,共11页
The main purpose of this paper is using the properties of the classical Gauss sum and the analytic methods to study the computational problem of one kind of hybrid power mean involving the character sum of polynomials... The main purpose of this paper is using the properties of the classical Gauss sum and the analytic methods to study the computational problem of one kind of hybrid power mean involving the character sum of polynomials and a sum analogous to Kloosterman sum mod p,an odd prime,and give two sharp asymptotic formulae for them. 展开更多
关键词 character sum of polynomials a sum analogous to Kloosterman sum hybrid power mean the classical Gauss sum analytic method asymptotic formula
原文传递
SHARP BOUNDS FOR TOADER-TYPE MEANS IN TERMS OF TWO-PARAMETER MEANS 被引量:2
10
作者 Yueying YANG Weimao QIAN +1 位作者 Hongwei ZHANG Yuming CHU 《Acta Mathematica Scientia》 SCIE CSCD 2021年第3期719-728,共10页
In the article,we prove that the double inequalities Gp[λ1a+(1-λ1)b,λ1 b+(1-λ1)a]A1-p(a,b)<T[A(a,b),G(a,b)]<Gp[μ1 a+(1-μ1)b,μ1b+(1-μ1)a]A1-p(a,b),Cs[λ^(2) a+(1-λ2)b,λ2 b+(1-λ2)a]A1-s(a,b)<T[A(a,b)... In the article,we prove that the double inequalities Gp[λ1a+(1-λ1)b,λ1 b+(1-λ1)a]A1-p(a,b)<T[A(a,b),G(a,b)]<Gp[μ1 a+(1-μ1)b,μ1b+(1-μ1)a]A1-p(a,b),Cs[λ^(2) a+(1-λ2)b,λ2 b+(1-λ2)a]A1-s(a,b)<T[A(a,b),Q(a,b)]<Cs[μ2 a+(1-μ2)b,μ2 b+(1-μ2)a]A1-p(a,b)hold for all a,b>0 with a≠b if and only ifλ1≤1/2-(1-(2/π)2/p)1/2/2,μ1≥1/2-(2p)1/2/(4 p),λ2≤1/2+(2(3/(2 s)(E(21/2/2)/π)1/s)-1)1/2/2 andμ2≥1/2+s1/2/(4 s)ifλ1,μ1∈(0,1/2),λ2,μ2∈(1/2,1),p≥1 and s≥1/2,where G(a,b)=(ab)1/2,A(a,b)=(a+b)/2,T(a,b)=∫0π/2(a2 cos2 t+b2 sin2)1/2 tdt/π,Q(a,b)=((a2+b2)/2)1/2,C(a,b)=(a2+b2)/(a+b)and E(r)=∫0π/2(1-r^(2) sin^(2))1/2 tdt. 展开更多
关键词 Geometric mean arithmetic mean Toader mean ontraharmonic mean complete elliptic integral
下载PDF
A novel noise reduction technique for underwater acoustic signals based on complete ensemble empirical mode decomposition with adaptive noise,minimum mean square variance criterion and least mean square adaptive filter 被引量:8
11
作者 Yu-xing Li Long Wang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第3期543-554,共12页
Underwater acoustic signal processing is one of the research hotspots in underwater acoustics.Noise reduction of underwater acoustic signals is the key to underwater acoustic signal processing.Owing to the complexity ... Underwater acoustic signal processing is one of the research hotspots in underwater acoustics.Noise reduction of underwater acoustic signals is the key to underwater acoustic signal processing.Owing to the complexity of marine environment and the particularity of underwater acoustic channel,noise reduction of underwater acoustic signals has always been a difficult challenge in the field of underwater acoustic signal processing.In order to solve the dilemma,we proposed a novel noise reduction technique for underwater acoustic signals based on complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN),minimum mean square variance criterion(MMSVC) and least mean square adaptive filter(LMSAF).This noise reduction technique,named CEEMDAN-MMSVC-LMSAF,has three main advantages:(i) as an improved algorithm of empirical mode decomposition(EMD) and ensemble EMD(EEMD),CEEMDAN can better suppress mode mixing,and can avoid selecting the number of decomposition in variational mode decomposition(VMD);(ii) MMSVC can identify noisy intrinsic mode function(IMF),and can avoid selecting thresholds of different permutation entropies;(iii) for noise reduction of noisy IMFs,LMSAF overcomes the selection of deco mposition number and basis function for wavelet noise reduction.Firstly,CEEMDAN decomposes the original signal into IMFs,which can be divided into noisy IMFs and real IMFs.Then,MMSVC and LMSAF are used to detect identify noisy IMFs and remove noise components from noisy IMFs.Finally,both denoised noisy IMFs and real IMFs are reconstructed and the final denoised signal is obtained.Compared with other noise reduction techniques,the validity of CEEMDAN-MMSVC-LMSAF can be proved by the analysis of simulation signals and real underwater acoustic signals,which has the better noise reduction effect and has practical application value.CEEMDAN-MMSVC-LMSAF also provides a reliable basis for the detection,feature extraction,classification and recognition of underwater acoustic signals. 展开更多
关键词 Underwater acoustic signal Noise reduction Empirical mode decomposition(EMD) Ensemble EMD(EEMD) complete EEMD with adaptive noise(CEEMDAN) Minimum mean square variance criterion(MMSVC) Least mean square adaptive filter(LMSAF) Ship-radiated noise
下载PDF
On the Mean Value of the Complete Trigonometric Sums with Dirichlet Characters 被引量:1
12
作者 Zhe Feng XU 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2007年第7期1341-1344,共4页
The main purpose of this paper is, using the analytic method, to study the mean value properties of the complete trigonometric sums with Dirichlet characters, and give an exact calculating formula for its fourth power... The main purpose of this paper is, using the analytic method, to study the mean value properties of the complete trigonometric sums with Dirichlet characters, and give an exact calculating formula for its fourth power mean. 展开更多
关键词 complete trigonometric sums Dirichlet character mean value
原文传递
ON COMPLETE SUBMANIFOLDS WITH PARALLEL MEAN CURVATURE IN NEGATIVE PINCHED MANIFOLDS 被引量:2
13
作者 Leng Yan Xu Hongwei Zhejiang University, Center of Mathematical Sciences Eangzhou 310027, China +1 位作者 Zhejiang University, Center of Mathematical Sciences Eangzhou 310027, China 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2007年第2期153-162,共10页
A rigidity theorem for oriented complete submanifolds with parallel mean curvature in a complete and simply connected Riemannian (n + p)-dimensional manifold N^n+p with negative sectional curvature is proved. For ... A rigidity theorem for oriented complete submanifolds with parallel mean curvature in a complete and simply connected Riemannian (n + p)-dimensional manifold N^n+p with negative sectional curvature is proved. For given positive integers n(≥ 2), p and for a constant H satisfying H 〉 1 there exists a negative number τ(n,p, H) ∈ (-1, 0) with the property that if the sectional curvature of N is pinched in [-1, τ-(n,p, H)], and if the squared length of the second fundamental form is in a certain interval, then N^n+p is isometric to the hyperbolic space H^n+P(-1). As a consequence, this submanifold M is congruent to S^n(1√H^2 - 1) or the Veronese surface in S^4(1/√H^2-1). 展开更多
关键词 complete submanifold rigidity theorem mean curvature second fundamental form pinchedRiemannian manifold
下载PDF
Simplifications of CQC method and CCQC method 被引量:5
14
作者 俞瑞芳 周锡元 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2007年第1期65-76,共12页
The response-spectrum mode superposition method is widely used for seismic response analyses of linear systems. In using this method, the complete quadratic combination (CQC) is adopted for classically damped linear... The response-spectrum mode superposition method is widely used for seismic response analyses of linear systems. In using this method, the complete quadratic combination (CQC) is adopted for classically damped linear systems and the complex complete quadratic combination (CCQC) formula is adopted for non-classically damped linear systems. However, in both cases, the calculation of seismic response analyses is very time consuming. In this paper, the variation of the modal correlation coefficients of displacement, velocity and displacement-velocity with frequency and damping ratios of two modes of interest are studied, Moreover, the calculation errors generated by using CQC and square-root-of-the-sum-of-thesquares (SRSS) methods (or CCQC and CSRSS methods) for different damping combinations are compared. In these analyses, some boundary lines for classically and non-classically damped systems are plotted to distinguish the allowed minimum frequency ratio at given geometric mean of the damping ratios of both modes if their relativity is neglected. Furthermore, the simplified method, which is a special mode quadratic combination method considering only relativity of adjacent modes in CQC method and named simplified CQC or partial quadratic combination (PQC) method for classically damped linear system, is proposed to improve computational efficiency, and the criterion for determination of how many correlated modes should be adopted is proposed. Similarly, the simplified CCQC or complex partial quadratic combination (CPQC) method for the non-classically damped linear system and the corresponding criterion are also deduced. Finally, a numerical example is given to illustrate the applicability, computational accuracy and efficiency of the PQC and CPQC methods. 展开更多
关键词 mode superposition non-classical damping complex complete quadratic combination partial quadraticcombination (PQC)
下载PDF
ON THE COMPLETE INTEGRABILITY OF NONLINEARIZED LAX SYSTEMS FOR THE CLASSICAL BOUSSINESQ HIERARCHY 被引量:1
15
作者 马文秀 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 1993年第1期92-96,共5页
The N involutive integrals of motion with linearly independent gradients for the nonlin earized eigenvalue problem corresponding to the classical Boussinesq (CB) hierarchy are given. It is shown that when n=1,2,3, the... The N involutive integrals of motion with linearly independent gradients for the nonlin earized eigenvalue problem corresponding to the classical Boussinesq (CB) hierarchy are given. It is shown that when n=1,2,3, the nonlinearized time parts of Lax systems for the CB hierarchy are transformed into three finite-dimensional integrable Hamiltonian systems under the constraint of the nonlinearized spatial part. 展开更多
关键词 ON the complete INTEGRABILITY of NONLINEARIZED LAX SYSTEMS FOR the CLASSICAL BOUSSINESQ HIERARCHY
原文传递
G-CPT Symmetry of Quantum Emergence and Submergence—An Information Conservational Multiagent Cellular Automata Unification of CPT Symmetry and CP Violation for Equilibrium-Based Many-World Causal Analysis of Quantum Coherence and Decoherence 被引量:2
16
作者 Wen-Ran Zhang 《Journal of Quantum Information Science》 2016年第2期62-97,共36页
An equilibrium-based YinYang bipolar dynamic Generalization of CPT (G-CPT) symmetry is introduced based on energy/information conservational quantum emergence-submergence. As a bottleneck of quantum computing, quantum... An equilibrium-based YinYang bipolar dynamic Generalization of CPT (G-CPT) symmetry is introduced based on energy/information conservational quantum emergence-submergence. As a bottleneck of quantum computing, quantum decoherence or collapse has been plaguing quantum mechanics for decades. It is suggested that the crux of the problem can trace its origin back to the incompleteness of CPT symmetry due to the lack of holistic representation for equilibrium-based bipolar coexistence. In this work, the notion of quantum emergence-submergence is coined as two opposite processes with bipolar energy/information conservation. The new notion leads to G-CPT symmetry supported by a Bipolar Quantum Cellular Automata (BQCA) interpretation of quantum mechanics. It is shown that the new interpretation further leads to the unification of electromagnetic particle-antiparticle bipolarity and gravitational action-reaction bipolarity as well as CPT symmetry and CP violation into a philosophically, geometrically and logically different quantum gravity theory. On one hand, G-CPT symmetry enables a Bipolar Quantum Agent (BQA) to emerge as a bipolar quantum superposition or entanglement coupled to a globally coherent BQCA;on the other hand, G-CP violation supports a causal theory of BQA submergence or decoupling from the global coherence. In turn, BQAs can submerge from one world but emerge in another within YinYang bipolar quantum geometry. It is suggested that all logical, physical, social, biological and mental worlds are bipolar quantum entangled under G-CPT symmetry. It is contended that G-CPT symmetry constitutes an analytical paradigm of quantum mechanics and quantum gravity—a fundamental departure from “what goes around comes around”. The new paradigm leads to a number of predictions and challenges. 展开更多
关键词 Negative-Positive Energy/Information Unification Information Conservation Equilibrium-Based Generalization complete Background-Independence Bipolar Quantum Geometry Bipolar Quantum Superposition Quantum Emergence-Submergence Quantum Coherence-Decoherence Classical World and Quantum World Symmetrical Measurement
下载PDF
Complete hypersurfaces in a 4-dimensional hyperbolic space
17
作者 XU Hong-wei1 ZHAO En-tao2 Center of Mathematical Sciences,Zhejiang University,Hangzhou 310027,China 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2009年第3期370-378,共9页
This paper gives a classification of complete hypersurfaces with nonzero constant mean curvature and constant quasi-Gauss-Kronecker curvature in the hyperbolic space H4(-1),whose scalar curvature is bounded from below.
关键词 complete hypersurface mean curvature quasi-Gauss-Kronecker curvature
下载PDF
COMPLETE MONOTONICITY OF THE PROBABILITY OF RUIN AND DE FINETTI'S DIVIDEND PROBLEM
18
作者 Hua DONG Chuancun YIN 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2012年第1期178-185,共8页
This paper studies the complete monotonicity of the probability of ruin in the the classical risk model and the classical risk model that is perturbed by a diffusion. As a byproduct, the authors give an alternative p... This paper studies the complete monotonicity of the probability of ruin in the the classical risk model and the classical risk model that is perturbed by a diffusion. As a byproduct, the authors give an alternative proof to a result on the optimal dividend problem due to Loeffen (2008). 展开更多
关键词 Barrier strategy classical risk model complete monotonicity LOG-CONVEXITY optimaldividend problem perturbed classical risk model.
原文传递
THE COMPLETE LANGLANDS PARAMETERS CORRESPONDING TO THE REPRESENTATIONS OF THE CLASSICAL GROUPS WITH INTEGRAL REGULAR INFINITESIMAL CHARACTERS
19
作者 HOUZIXIN ZHAOQIANG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 1996年第1期53-62,共10页
The authors determine all the complete Langlands parameters corresponding to the representations of the classical groups with integral regular infintesimal characters, and get all L-packts in that case.
关键词 L-packet complete Langlands parameter Classical group
原文传递
Comparison of Four Methods for Handing Missing Data in Longitudinal Data Analysis through a Simulation Study
20
作者 Xiaoping Zhu 《Open Journal of Statistics》 2014年第11期933-944,共12页
Missing data can frequently occur in a longitudinal data analysis. In the literature, many methods have been proposed to handle such an issue. Complete case (CC), mean substitution (MS), last observation carried forwa... Missing data can frequently occur in a longitudinal data analysis. In the literature, many methods have been proposed to handle such an issue. Complete case (CC), mean substitution (MS), last observation carried forward (LOCF), and multiple imputation (MI) are the four most frequently used methods in practice. In a real-world data analysis, the missing data can be MCAR, MAR, or MNAR depending on the reasons that lead to data missing. In this paper, simulations under various situations (including missing mechanisms, missing rates, and slope sizes) were conducted to evaluate the performance of the four methods considered using bias, RMSE, and 95% coverage probability as evaluation criteria. The results showed that LOCF has the largest bias and the poorest 95% coverage probability in most cases under both MAR and MCAR missing mechanisms. Hence, LOCF should not be used in a longitudinal data analysis. Under MCAR missing mechanism, CC and MI method are performed equally well. Under MAR missing mechanism, MI has the smallest bias, smallest RMSE, and best 95% coverage probability. Therefore, CC or MI method is the appropriate method to be used under MCAR while MI method is a more reliable and a better grounded statistical method to be used under MAR. 展开更多
关键词 MCAR MAR complete CASE Mean SUBSTITUTION LOCF Multiple IMPUTATION
下载PDF
上一页 1 2 23 下一页 到第
使用帮助 返回顶部