全文获取类型
收费全文 | 2110篇 |
免费 | 89篇 |
国内免费 | 211篇 |
专业分类
化学 | 169篇 |
晶体学 | 4篇 |
力学 | 89篇 |
综合类 | 31篇 |
数学 | 1794篇 |
物理学 | 323篇 |
出版年
2023年 | 26篇 |
2022年 | 28篇 |
2021年 | 17篇 |
2020年 | 33篇 |
2019年 | 52篇 |
2018年 | 26篇 |
2017年 | 51篇 |
2016年 | 52篇 |
2015年 | 32篇 |
2014年 | 73篇 |
2013年 | 163篇 |
2012年 | 76篇 |
2011年 | 96篇 |
2010年 | 95篇 |
2009年 | 101篇 |
2008年 | 103篇 |
2007年 | 142篇 |
2006年 | 109篇 |
2005年 | 102篇 |
2004年 | 87篇 |
2003年 | 99篇 |
2002年 | 88篇 |
2001年 | 66篇 |
2000年 | 98篇 |
1999年 | 69篇 |
1998年 | 84篇 |
1997年 | 68篇 |
1996年 | 44篇 |
1995年 | 26篇 |
1994年 | 36篇 |
1993年 | 24篇 |
1992年 | 17篇 |
1991年 | 27篇 |
1990年 | 11篇 |
1989年 | 8篇 |
1988年 | 15篇 |
1987年 | 17篇 |
1986年 | 12篇 |
1985年 | 26篇 |
1984年 | 22篇 |
1983年 | 4篇 |
1982年 | 12篇 |
1981年 | 11篇 |
1980年 | 13篇 |
1979年 | 17篇 |
1978年 | 12篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1975年 | 2篇 |
1974年 | 3篇 |
排序方式: 共有2410条查询结果,搜索用时 15 毫秒
111.
利用锥上不动点定理讨论了二阶常微分方程组多点边值问题正解的存在性,所得结论推广了最近的一些结果. 相似文献
112.
N. G. Fytas A. Malakis 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,61(1):111-120
The one-parametric Wang-Landau (WL) method is
implemented together with an extrapolation scheme to yield
approximations of the two-dimensional (exchange-energy,
field-energy) density of states (DOS) of the 3D bimodal
random-field Ising model (RFIM). The present approach generalizes
our earlier WL implementations, by handling the final stage of the
WL process as an entropic sampling scheme, appropriate for the
recording of the required two-parametric histograms. We test the
accuracy of the proposed extrapolation scheme and then apply it to
study the size-shift behavior of the phase diagram of the 3D
bimodal RFIM. We present a finite-size converging approach and a
well-behaved sequence of estimates for the critical disorder
strength. Their asymptotic shift-behavior yields the critical
disorder strength and the associated correlation length's
exponent, in agreement with previous estimates from ground-state
studies of the model. 相似文献
113.
For a translation invariant Gibbs measure on the configuration space X of a lattice finite spin system, we consider the set X
of generic points. Using a Breiman type convergence theorem on the set X
of generic points of an arbitrary translation invariant probability measure on X, we evaluate the Hausdorff dimension of the set X
with respect to any metric out of a wide class of scale metrics on X (including Billingsley metrics generated by Gibbs measures). 相似文献
114.
We compute renormalization-group fixed points and their spectrum in an ultralocal approximation. We study a case of two competing nontrivial fixed points for a three-dimensional real N-component field: the O(N)-invariant fixed point vs. the cubic-invariant fixed point. We compute the critical value N
c of the cubic
4-perturbation at the O(N)-fixed point. The O(N)-fixed point is stable under a cubic
4-perturbation below N
c; above N
c it is unstable. The Critical value comes out as 2.219435<N
c<2.219436 in the ultralocal approximation. We also compute the critical value of N at the cubic invariant fixed point. Within the accuracy of our computations, the two values coincide. 相似文献
115.
We present an algorithm for variational inequalities VI(
, Y) that uses a primal-dual version of the Analytic Center Cutting Plane Method. The point-to-set mapping
is assumed to be monotone, or pseudomonotone. Each computation of a new analytic center requires at most four Newton iterations, in theory, and in practice one or sometimes two. Linear equalities that may be included in the definition of the set Y are taken explicitly into account.We report numerical experiments on several well—known variational inequality problems as well as on one where the functional results from the solution of large subproblems. The method is robust and competitive with algorithms which use the same information as this one. 相似文献
116.
117.
118.
119.
Van Roie B Denolf K Pitsi G Thoen J 《The European physical journal. E, Soft matter》2005,16(4):361-364
We investigated the smectic-A-hexatic-B (SmA-HexB) transition in the liquid-crystal n-hexyl-4-n-pentyloxybiphenyl-4-carboxilate (65OBC) with adiabatic scanning calorimetry. We were able to prove in a direct way that this transition is indeed very weakly first order, as was already suggested in the literature. The latent heat at the transition was determined to be HL = 0.04±0.02 J/g. Our experiments confirm the high value for the heat capacity critical exponent earlier reported, yielding = 0.64±0.05. 相似文献
120.
For problems in the calculus of variations with
isoperimetric side constraints, we provide in this paper a set of
points whose emptiness, independently of nonsingularity assumptions,
is equivalent to the nonnegativity of the second variation along
admissible variations. The main objective of introducing a
characterization of this condition should be, of course, to obtain a
simpler way of verifying it. There are two other sets of points
available in the literature, introduced by Loewen and Zheng (1994)
and Zeidan (1996), for which this necessary condition implies their
emptiness. However, we show that verifying membership of these sets
may be more difficult than checking directly if that condition
holds. Contrary to this behavior, we prove that the desired
objective of characterizing that condition is achieved by means of
the set introduced in this paper. 相似文献