全文获取类型
收费全文 | 651篇 |
免费 | 23篇 |
国内免费 | 10篇 |
专业分类
化学 | 2篇 |
晶体学 | 1篇 |
力学 | 5篇 |
数学 | 561篇 |
物理学 | 115篇 |
出版年
2023年 | 5篇 |
2022年 | 7篇 |
2021年 | 7篇 |
2020年 | 41篇 |
2019年 | 41篇 |
2018年 | 25篇 |
2017年 | 23篇 |
2016年 | 17篇 |
2015年 | 28篇 |
2014年 | 48篇 |
2013年 | 101篇 |
2012年 | 26篇 |
2011年 | 31篇 |
2010年 | 19篇 |
2009年 | 32篇 |
2008年 | 31篇 |
2007年 | 38篇 |
2006年 | 27篇 |
2005年 | 18篇 |
2004年 | 10篇 |
2003年 | 13篇 |
2002年 | 13篇 |
2001年 | 15篇 |
2000年 | 17篇 |
1999年 | 8篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 8篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有684条查询结果,搜索用时 15 毫秒
101.
We characterize the value function and the optimal stopping time for a large class of optimal stopping problems where the underlying process to be stopped is a fairly general Markov process. The main result is inspired by recent findings for Lévy processes obtained essentially via the Wiener–Hopf factorization. The main ingredient in our approach is the representation of the β-excessive functions as expected suprema. A variety of examples is given. 相似文献
102.
Fouzia Baghery 《随机分析与应用》2013,31(3):705-717
Abstract We study the problem of optimal control of a jump diffusion, that is, a process which is the solution of a stochastic differential equation driven by Lévy processes. It is required that the control process is adapted to a given subfiltration of the filtration generated by the underlying Lévy processes. We prove two maximum principles (one sufficient and one necessary) for this type of partial information control. The results are applied to a partial information mean-variance portfolio selection problem in finance. 相似文献
103.
Andrew S. Dickinson 《随机分析与应用》2013,31(5):1109-1128
Abstract In this article, a theorem is proved that describes the optimal approximation (in the L 2(?)-sense) of the second iterated integral of a standard two-dimensional Wiener process, W, by a function of finitely many elements of the Gaussian Hilbert space generated by W. This theorem has some interesting corollaries: First of all, it implies that Euler's method has the optimal rate of strong convergence among all algorithms that depend solely on linear functionals of the Wiener process, W; second, it shows that the approximation of the second iterated integral based on Karhunen–Loève expansion of the Brownian bridge is asymptotically optimal. 相似文献
104.
V. Schwämmle F. D. Nobre C. Tsallis 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,66(4):537-546
The stability of q-Gaussian distributions as particular solutions of the
linear diffusion equation and its generalized nonlinear form, , the porous-medium equation, is investigated through both numerical
and analytical approaches. An analysis of the kurtosis of the distributions strongly suggests that an initial q-Gaussian, characterized by an index qi, approaches asymptotically the
final, analytic solution of the porous-medium equation, characterized by an index q, in such a way that the relaxation rule for
the kurtosis evolves in time according to a q-exponential, with a relaxation index qrel ≡qrel(q). In some cases, particularly when one attempts to transform an infinite-variance distribution (qi ≥ 5/3) into a finite-variance
one (q < 5/3), the relaxation towards the asymptotic solution may occur very slowly in time. This fact might shed some light
on the slow relaxation, for some long-range-interacting many-body Hamiltonian systems, from long-standing quasi-stationary
states to the ultimate thermal equilibrium
state. 相似文献
105.
《Stochastic Processes and their Applications》2020,130(8):4766-4792
We consider Malliavin smoothness of random variables , where is a pure jump Lévy process and the function is either bounded and Hölder continuous or of bounded variation. We show that Malliavin differentiability and fractional differentiability of depend both on the regularity of and the Blumenthal–Getoor index of the Lévy measure. 相似文献
106.
Vi Le Etienne Pardoux 《Stochastics An International Journal of Probability and Stochastic Processes》2020,92(6):852-875
Consider a general continuous-state branching process with additional interaction, which destroys the branching property. We give precise conditions on the interaction term, in order to decide whether the extinction time of the process remains or not bounded as the initial value tends to infinity, and similarly for the total mass of the process. 相似文献
107.
《Stochastic Processes and their Applications》2020,130(12):7547-7574
108.
We adopt a new approach to find Laplace transforms of joint occupation times over disjoint intervals for spectrally negative Lévy processes. The Laplace transforms are expressed in terms of scale functions. 相似文献
109.
110.
We provide new closed‐form approximations for the pricing of spread options in three specific instances of exponential Lévy markets, ie, when log‐returns are modeled as Brownian motions (Black‐Scholes model), variance gamma processes (VG model), or normal inverse Gaussian processes (NIG model). For the specific case of exchange options (spread options with zero strike), we generalize the well‐known Margrabe formula (1978) that is valid in a Black‐Scholes model to the VG model under a homogeneity assumption. 相似文献