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741.
Using numerically exact solution of the time-dependent Schrödinger equation together with time-dependent quantum Monte Carlo (TDQMC) calculations, here we compare the effects of spatial nonlocality versus nonlocal causality for the ground state and for real-time evolution of two entangled electrons in parabolic potential in one spatial dimension. It was found that the spatial entanglement quantified by the linear quantum entropy is predicted with good accuracy using the spatial nonlocality, parameterized naturally within the TDQMC approach. At the same time, the nonlocal causality predicted by the exact solution leads to only small oscillations in the quantum trajectories which belong to the idler electron as the driven electron is subjected to a strong high frequency electric field, without interaction between the electrons.  相似文献   
742.
中国金融结构与产业结构经济结构关系的实证研究   总被引:9,自引:0,他引:9  
毛定祥 《运筹与管理》2006,15(5):122-127
本文依据协整理论,利用向量误差修正模型,对中国金融结构与产业结构、经济结构之间的关系进行了实证研究.Granger因果检验的结果表明,中国正处于从转轨经济向成熟的市场经济过渡的发展阶段.同时,中国的金融结构与经济结构之间存在不协调.据此我们得出了相应的政策含义.  相似文献   
743.
Air‐plasma‐sprayed (APS) thermal barrier coatings (TBCs) under the conditions of without TBC, as‐sprayed and preoxidized, were tested under tensile loading, and their acoustic emission (AE) responses were monitored. AE parameters including event count, amplitude, and frequency spectrum realized by Fast Fourier Transformation (FFT) were analyzed for information regarding the fracture behavior of TBCs. On the basis of AE behavior, the fracture process of TBCs and corresponding cracking patterns in TBCs subjected to tensile tests were evaluated. AE results also showed that the bondcoating oxidation not only promotes the cracking but also changes the failure mode in TBCs. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
744.
The complexes formed by combining Pd(OAc)2 and iminophosphine ligands (P^N) are active catalysts in Suzuki–Miyaura cross-coupling reactions under mild conditions. Aryl bromides and iodides, as well as benzyl chlorides give the corresponding coupled products in high yields at low temperatures (25–50 °C) using these catalysts. Iminophosphines containing the most sterically demanding groups attached to the N-imino moiety were the most effective ligands. New divalent Pd complexes of known iminophosphines were synthesised and their activity was compared with the in situ generated catalyst system. The complex resulting from the oxidative addition of 4-bromo anisole [Pd(4-CH3OC6H4)Br(P^N)] was more active than the in situ generated system. However, palladacycles containing the iminophosphine ligand (e.g., {[C6H4CH(Me)2St-Bu]Pd(P^N)}+PF6) were less active than the in situ generated catalyst due to the greater stability of the complexes that involve two bidentate ligands. Poisoning tests demonstrated that homogeneous mononuclear palladium species containing the iminophsophine ligand were responsible for the catalytic activity.  相似文献   
745.
In accelerated life tests (ALTs), test units are often tested in multiple test chambers along with different stress conditions. The nonhomogeneity of test chambers precludes the complete randomized experiment and may affect the life‐stress relationship of the test product. The chamber‐to‐chamber variation should be taken into account for ALT planning so as to obtain more accurate test results. In this paper, planning ALTs under a nested experimental design structure with random test chamber effects is studied. First, by a 2‐phase approach, we illustrate to what extent different test chamber assignments to stress conditions may impact the estimation of unknown parameters. Then, D‐optimal test plans with 2 test chambers are considered. To construct the optimal design, we establish the generalized linear mixed model for failure‐time data and apply a quasi‐likelihood method, where test chamber assignments, as well as other decision variables that are required for planning ALTs, are simultaneously determined.  相似文献   
746.
This paper explores the co-movement of Shanghai stock market and China Yuan (CNY) exchange rates. First, we find that stock price and exchange rate are significantly cross-correlated. Second, employing a cointegration test allowing for a structural break, we find that the Shanghai Composite Index (SCI) is not cointegrated with the exchange rate of CNY/USD. The so-called “cointegration” found in previous studies is just caused by the shock of the recent financial crisis. Third, using linear and nonlinear Granger causality tests, we find no causality between stock prices and exchange rates during the period before the recent financial crisis. After the financial crisis, a unidirectional causality behavior running from exchange rates to stock index is present.  相似文献   
747.
The primary aim of this paper is to expose the use and the value of spatial statistical analysis in business and especially in designing economic policies in rural areas. Specifically, we aim to present under a unified framework, the use of both point and area‐based methods, in order to analyze in‐depth economic data, as well as, to drive conclusions through interpreting the analysis results. The motivating problem is related to the establishment of women‐run enterprises in a rural area of Greece. Moreover, in this article, the spatial scan statistic is successfully applied to the spatial economic data at hand, in order to detect possible clusters of small women‐run enterprises in a rural mountainous and disadvantaged region of Greece. Then, it is combined with Geographical Information System based on Local Indicator of Spatial Autocorrelation scan statistic for further exploring and interpreting the spatial patterns. The rejection of the random establishment of women‐run enterprises and the interpretation of the clustering patterns are deemed necessary, in order to assist government in designing policies for rural development. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
748.
We calculate the contribution of pions to the $\bar qq$-expectation value κ(ρ) =<Mq q|M> in symmetric nuclear matter. We employ exact pion propagator renormalized by nucleon-hole and isobar-hole excitations. Conventional straightforward calculation leads to the “pion condensation” at unrealistically small values of densities, causing even earlier restoration of chiral symmetry. This requires a self-consistent approach, consisting in using the models, which include direct dependence of in-medium mass values on κ(ρ), e.g. the Nambu–Jona-Lasinio–model. We show, that in the self-consistent approach the ρ-dependence of the condensate is described by a smooth curve. The “pion condensate” point is removed to much higher values of density. The chiral restoration does not take place at least while ρ < 2.8ρ0 with ρ0 being the saturation value. Validity of our approach is limited by possible accumulation of heavier baryons (delta isobars) in the ground state of nuclear matter. For the value of effective nucleon mass at the saturation density we found m *0) = 0.6m, consistent with nowadays results of other authors. Received: 8 October 1998  相似文献   
749.
We consider a two-factor experiment in which the factors have the same levels with a natural ordering among the levels. Likelihood ratio tests for testing equality of the main effects with a one-sided alternative and for testing the one-sided hypothesis as a null hypothesis are studied. Closed form expressions for the maximum likelihood estimates under the various hypotheses are obtained. The null hypothesis distributions for these test statistics are derived.The efforts of the first author were supported by the NSERC of Canada. The efforts of the second author were supported by the Office of Naval Research under Contract ONR N00014-80-C-0321. The efforts of the third author were supported by the Office of Naval Research under Contract ONR N00014-80-C-0322.  相似文献   
750.
Some goodness-of-fit tests based on the L 1-norm are considered. The asymptotic distribution of each statistic under the null hypothesis is the distribution of the L 1-norm of the standard Wiener process on [0,1]. The distribution function, the density function and a table of some percentage points of the distribution are given. A result for the asymptotic tail probability of the L 1-norm of a Gaussian process is also obtained. The result is useful for giving the approximate Bahadur efficiency of the test statistics whose asymptotic distributions are represented as the L 1-norms of Gaussian processes.  相似文献   
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