全文获取类型
收费全文 | 2599篇 |
免费 | 88篇 |
国内免费 | 16篇 |
专业分类
化学 | 1575篇 |
晶体学 | 14篇 |
力学 | 52篇 |
数学 | 504篇 |
物理学 | 558篇 |
出版年
2024年 | 5篇 |
2023年 | 30篇 |
2022年 | 74篇 |
2021年 | 87篇 |
2020年 | 71篇 |
2019年 | 121篇 |
2018年 | 87篇 |
2017年 | 81篇 |
2016年 | 99篇 |
2015年 | 82篇 |
2014年 | 110篇 |
2013年 | 137篇 |
2012年 | 178篇 |
2011年 | 193篇 |
2010年 | 118篇 |
2009年 | 91篇 |
2008年 | 169篇 |
2007年 | 146篇 |
2006年 | 142篇 |
2005年 | 125篇 |
2004年 | 112篇 |
2003年 | 70篇 |
2002年 | 63篇 |
2001年 | 26篇 |
2000年 | 37篇 |
1999年 | 24篇 |
1998年 | 21篇 |
1997年 | 28篇 |
1996年 | 20篇 |
1995年 | 16篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1981年 | 10篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1977年 | 8篇 |
1975年 | 12篇 |
1974年 | 7篇 |
1973年 | 4篇 |
1972年 | 6篇 |
1971年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有2703条查询结果,搜索用时 0 毫秒
91.
M. I. Shirokov 《International Journal of Theoretical Physics》2003,42(4):705-710
In order to obtain sum rules and spectral representations the Hermiticity property , A = A, of observables is used. It is shown that for certain and the property turns out to be inconsistent with the commutation relations that contain A. The known Schwinger paradox is explained by this inconsistency. 相似文献
92.
2,3-Di(pyrrole-2-yl)quinoxaline anion sensors with extended chromophores display dramatic enhancement in fluorescence intensity (sensing output), increased affinity for inorganic anions as well as strong selectivity for pyrophosphate over phosphate anion. 相似文献
93.
Electrospray ionization mass spectrometry (ESI‐MS) was successfully applied to the structural analysis of lignin. The structure of oligomers fractionated from Eucalyptus globulus dioxane lignin was elucidated using tandem mass spectrometry, and the information on fragmentation patterns was provided by experiments on dimeric model compounds. Data obtained revealed a significant abundance in the lignin macromolecules of linear fragments that were composed of 8‐O‐4′‐linked syringyl/guaiacyl units and syringaresinol.
94.
We study a class of $E_0$ -semigroups of endomorphisms of a von Neumann factor $\mathcal{M}$ possessing the following property: an $e_0$ -semigroup of endomorphisms of $\mathcal{B}\left( \mathcal{H} \right)$ , where $\mathcal{H}$ is the standard representation space for $\mathcal{M}$ , and a product system of Hilbert spaces can be associated with each of these $E_0$ -semigroups. 相似文献
95.
We introduce the notion of the
-prolongation of Lie algebras of differential operators on homogeneous spaces. The
-prolongations are topological invariants that coincide with one-dimensional cohomologies of the corresponding Lie algebras in the case where V is a homogeneous space. We apply the obtained results to the spaces S
1 (the Virasoro algebra) and
. 相似文献
96.
N. A. Shirokov 《Journal of Mathematical Sciences》2003,115(2):2287-2295
A function
analytic in the unit disk is called (p, A)-lacunary if the inequalities n
k Ak
p hold for all k 0 with some 1 < p < and A > 0. In this paper, for 1 < p < 2 and A > 0, we construct a (p, A)-lacunary function f
1,p,A
(z) decreasing as x 1 – 0 at a rate close to the optimal rate for (p, A)-lacunary functions. Bibliography: 6 titles. 相似文献
97.
We define the Krichever-Novikov-type Lie algebras of differential operators and pseudodifferential symbols on Riemann surfaces,
along with their outer derivations and central extensions. We show that the corresponding algebras of meromorphic operators
and symbols have many invariant traces and central extensions, given by the logarithms of meromorphic vector fields. Very
few of these extensions survive after passing to the algebras of operators and symbols holomorphic away from several fixed
points. We also describe the associated Manin triples and KdV-type hierarchies, emphasizing the similarities and differences
with the case of smooth symbols on the circle. 相似文献
98.
The paper introduces singular integral operators of a new type defined in the space L p with the weight function on the complex plane. For these operators, norm estimates are derived. Namely, if V is a complex-valued function on the complex plane satisfying the condition |V(z) ? V(??)| ?? w|z ? ??| and F is an entire function, then we put $$P_F^* f(z) = \mathop {\sup }\limits_{\varepsilon > 0} \left| {\int\limits_{\left| {\zeta - z} \right| > \varepsilon } {F\left( {\frac{{V(\zeta ) - V(z)}} {{\zeta - z}}} \right)\frac{{f(\zeta )}} {{\left( {\zeta - z} \right)^2 }}d\sigma (\zeta )} } \right|.$$ It is shown that if the weight function ?? is a Muckenhoupt A p weight for 1 < p < ??, then $$\left\| {P_F^* f} \right\|_{p,\omega } \leqslant C(F,w,p)\left\| f \right\|_{p,\omega } .$$ . 相似文献
99.
100.
Ryabukhin SV Plaskon AS Volochnyuk DM Shivanyuk AN Tolmachev AA 《The Journal of organic chemistry》2007,72(19):7417-7419
A convenient one-pot method for the synthesis of 2,3-dihydro-1H-benzimidazoles has been elaborated. A set of 2,3-dihydro-1H-benzimidazoles was prepared from various ortho-dialkylaminoanilines and aldehydes using Me3SiCl as a condensation agent and pyridine as a basic medium. 相似文献