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231.
The profitability of investment projects in the modified Cantor-Lipman model is analyzed. The possibility of making lower estimates of the investment project profitability by searching for periodic trajectories is studied. The necessary and sufficient conditions for the existence of a trajectory with the period 2 are derived. The sufficient conditions ensuring the existence of a certain trajectory with the period 2 are derived in the form of explicit requirements on the investment project structure. 相似文献
232.
Methodology and Computing in Applied Probability - Consider a problem of estimation of a cumulative distribution function of a random variable supported on a finite interval, with a circular random... 相似文献
233.
234.
Aditya Kaushik 《Numerical Methods for Partial Differential Equations》2008,24(1):217-238
This paper deals with the construction of a nonstandard numerical method to compute the travelling wave solutions of nonlinear reaction diffusion equations at high wave speeds. Related general properties are studied using the perturbation approximation. At high wave speed the perturbation parameter approaches to zero and the problem exhibits a multiscale character. That is, there are thin layers where the solution varies rapidly, while away from these layers the solution behaves regularly and varies slowly. Most of the conventional methods fail to capture this layer behavior. Thus, the quest for some new numerical techniques that may handle the travelling wave solutions at high wave speeds earns relevance. In this paper, one such parameter robust nonstandard numerical scheme is constructed, in the sense that its numerical solution converges in the maximum norm to the exact solution uniformly well for all finite wave speeds. To overcome the difficulty due to the nonlinearity, the problem is linearized using the quasilinearization process followed by nonstandard finite difference discretization. An extensive amount of analysis is carried out which uses a suitable decomposition of the error into smooth and singular component and a comparison principle combined with appropriate barrier functions. The error estimates are obtained, which ensures uniform convergence of the method. A set of numerical experiment is carried out in support of the predicted theory that validates computationally the theoretical results. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007 相似文献
235.
236.
State and parameter estimations of non-linear dynamical systems, based on incomplete and noisy measurements, are considered using Monte Carlo simulations. Given the measurements, the proposed method obtains the marginalized posterior distribution of an appropriately chosen (ideally small) subset of the state vector using a particle filter. Samples (particles) of the marginalized states are then used to construct a family of conditionally linearized system of equations and thus obtain the posterior distribution of the states using a bank of Kalman filters. Discrete process equations for the marginalized states are derived through truncated Ito-Taylor expansions. Increased analyticity and reduced dispersion of weights computed over a smaller sample space of marginalized states are the key features of the filter that help achieve smaller sample variance of the estimates. Numerical illustrations are provided for state/parameter estimations of a Duffing oscillator and a 3-DOF non-linear oscillator. Performance of the filter in parameter estimation is also assessed using measurements obtained through experiments on simple models in the laboratory. Despite an added computational cost, the results verify that the proposed filter generally produces estimates with lower sample variance over the standard sequential importance sampling (SIS) filter. 相似文献
237.
We investigate the uniform convergence of the density of the empirical measure of an ergodic diffusion. It is known that under
certain conditions on the drift and diffusion coefficients of the diffusion, the empirical density f
t converges in probability to the invariant density f, uniformly on the entire real line. We show that under the same conditions, uniform convergence of f
t to f on compact intervals takes place almost surely. Moreover, we prove that under much milder conditions (the usual linear growth
condition on the drift and diffusion coefficients and a finite second moment of the invariant measure suffice), we have the
uniform convergence of f
t to f on compacta in probability.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
238.
导出了具有正定对称核的积分方程最小特征值的一个下界估计式,为此为基础,获得了相应特征值的一种算法。 相似文献
239.
研究随机设计下噪声为厚尾随机变量时非参数函数中的变点估计问题.首先,通过设计变换将随机设计转化为等间距固定设计,进而利用小波方法估计变换后的变点的位置,再利用逆设计变换求得随机设计下变点位置的估计,并给出估计的收敛速度.模拟研究结果说明对于无穷方差厚尾过程中的变点估计问题小波方法是有效的. 相似文献
240.