全文获取类型
收费全文 | 3954篇 |
免费 | 349篇 |
国内免费 | 307篇 |
专业分类
化学 | 356篇 |
晶体学 | 5篇 |
力学 | 324篇 |
综合类 | 65篇 |
数学 | 2892篇 |
物理学 | 968篇 |
出版年
2024年 | 4篇 |
2023年 | 30篇 |
2022年 | 71篇 |
2021年 | 101篇 |
2020年 | 79篇 |
2019年 | 91篇 |
2018年 | 76篇 |
2017年 | 92篇 |
2016年 | 116篇 |
2015年 | 65篇 |
2014年 | 135篇 |
2013年 | 359篇 |
2012年 | 176篇 |
2011年 | 214篇 |
2010年 | 201篇 |
2009年 | 240篇 |
2008年 | 260篇 |
2007年 | 278篇 |
2006年 | 236篇 |
2005年 | 203篇 |
2004年 | 159篇 |
2003年 | 198篇 |
2002年 | 170篇 |
2001年 | 129篇 |
2000年 | 119篇 |
1999年 | 109篇 |
1998年 | 119篇 |
1997年 | 101篇 |
1996年 | 70篇 |
1995年 | 53篇 |
1994年 | 39篇 |
1993年 | 41篇 |
1992年 | 28篇 |
1991年 | 21篇 |
1990年 | 25篇 |
1989年 | 20篇 |
1988年 | 28篇 |
1987年 | 23篇 |
1986年 | 15篇 |
1985年 | 25篇 |
1984年 | 14篇 |
1983年 | 9篇 |
1982年 | 17篇 |
1981年 | 9篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 9篇 |
1973年 | 5篇 |
排序方式: 共有4610条查询结果,搜索用时 7 毫秒
21.
Suppose r ≥ 2 is a real number. A proper r‐flow of a directed multi‐graph is a mapping such that (i) for every edge , ; (ii) for every vertex , . The circular flow number of a graph G is the least r for which an orientation of G admits a proper r‐flow. The well‐known 5‐flow conjecture is equivalent to the statement that every bridgeless graph has circular flow number at most 5. In this paper, we prove that for any rational number r between 2 and 5, there exists a graph G with circular flow number r. © 2003 Wiley Periodicals, Inc. J Graph Theory 43: 304–318, 2003 相似文献
22.
We study the maximal term of the Hadamard composition of Dirichlet series with real exponents. We obtain a lower estimate for the sum of a Dirichlet series over a curve arbitrarily approaching the convergence line. 相似文献
23.
A. Aizpuru F.J. Pérez-Fernández 《Journal of Mathematical Analysis and Applications》2003,284(1):89-96
Several classical results on uniform convergence of unconditionally Cauchy series are generalized to weakly unconditionally Cauchy series. This uniform convergence is characterized through subalgebras and subfamilies of . A generalization of the Orlicz-Pettis theorem is also proved by mean of subalgebras of . 相似文献
24.
Using multiple q-integrals and a determinant evaluation, we establish a nonterminating 8φ7 summation for the root system Cr. We also give some important specializations explicitly. 相似文献
25.
With some applications in view, the following problem is solved in some special case which is not too special. LetF(s) =Σ
n
∞
=1an
λ
n
−s
be a generalized Dirichlet series with 1 =λ
1 <λ
2 < …,λ
n≤Dn, andλ
n+1 -λ
n ≥D
− 1
λ
n+1
− a
where α>0 andD(≥ 1) are constants. Then subject to analytic continuation and some growth conditions, a lower bound is obtained for
. These results will be applied in other papers to appear later. 相似文献
26.
Examples of exact expressions for the moments (mainly of the mean) of functions of sample moments are given. These provide checks on alternative developments such as asymptotic series for n, and simulation processes. Exact expressions are given for the mean of the square of the sample coefficient of variation, particularly in uniform sampling; Frullani integrals studied by G. H. Hardy arise. It should be kept in mind that exact results for (joint) moment generating functions (mgfs) are of interest as they produce a means of obtaining exact results for (cross) moments—including moments with negative indices. Thus an exact expression for the joint mgf of the 1st two noncentral moments can be used to obtain the mean of the (c.v.)2 (but not for the mean of the c..). A general expression is given for the moment generating function of the sample variance. The limitations of Fisher's symbolic formula for the characteristic function of sample moments (or more general statistics) are noted.This research was sponsored by the Applied Mathematical Sciences Research program, Office of Energy Research, U. S. Department of Energy under contract DE-AC0584OR21400 with the Martin Marietta Energy Systems. Inc. 相似文献
27.
Feng Dejun 《分析论及其应用》2003,19(4)
1 IntroductionForany 0 <λ <1 ,letνλ denotethedistributionof ∞n=0 εnλn wherethecoefficientsεnareeither0or1 ,chosenindependentlywithprobability12 foreach .Itistheinfiniteconvo lutionproductofthedistributions 12 (δ0 +δλn) ,givingrisetotheterm“infiniteBernoulliconvolution”orsimply“Bernoulliconvolution” .TheBernoulliconvolutioncanbeexpressedasaself similarmeasureνλsatisfyingtheequationνλ =12 νλ φ- 10 + 12 νλ φ- 11,( 1 .1 )whereφ0 (x) =λxand φ1(x) =λx + 1 .Thisme… 相似文献
28.
Michel Talagrand 《Journal of Theoretical Probability》1992,5(2):327-331
Consider a (complex) Banach spaceX, such thatX CO, and vectors(X
i
)
i
ofX. Consider an independent standard normal sequence(g
i
)
i
. Then if anX-valued random Fourier series |k|
n
e
ikt
g
k
x
k
satisfies
相似文献
29.
Tonghai Yang 《Transactions of the American Mathematical Society》2003,355(7):2663-2674
In this paper, we give an explicit formula for the first two terms of the Taylor expansion of a classical Eisenstein series of weight for . Both the first term and the second term have interesting arithmetic interpretations. We apply the result to compute the central derivative of some Hecke -functions.
30.
|