全文获取类型
收费全文 | 3320篇 |
免费 | 109篇 |
国内免费 | 23篇 |
专业分类
化学 | 2200篇 |
晶体学 | 24篇 |
力学 | 73篇 |
数学 | 603篇 |
物理学 | 552篇 |
出版年
2023年 | 18篇 |
2021年 | 24篇 |
2020年 | 40篇 |
2019年 | 53篇 |
2018年 | 43篇 |
2017年 | 31篇 |
2016年 | 71篇 |
2015年 | 63篇 |
2014年 | 101篇 |
2013年 | 194篇 |
2012年 | 153篇 |
2011年 | 183篇 |
2010年 | 123篇 |
2009年 | 117篇 |
2008年 | 170篇 |
2007年 | 158篇 |
2006年 | 154篇 |
2005年 | 146篇 |
2004年 | 119篇 |
2003年 | 95篇 |
2002年 | 56篇 |
2001年 | 22篇 |
2000年 | 28篇 |
1999年 | 26篇 |
1998年 | 25篇 |
1997年 | 44篇 |
1996年 | 54篇 |
1995年 | 50篇 |
1994年 | 45篇 |
1993年 | 48篇 |
1992年 | 48篇 |
1991年 | 54篇 |
1990年 | 37篇 |
1989年 | 45篇 |
1988年 | 51篇 |
1987年 | 41篇 |
1986年 | 49篇 |
1985年 | 51篇 |
1984年 | 58篇 |
1983年 | 39篇 |
1982年 | 35篇 |
1981年 | 41篇 |
1980年 | 51篇 |
1979年 | 41篇 |
1978年 | 39篇 |
1977年 | 36篇 |
1976年 | 31篇 |
1975年 | 27篇 |
1974年 | 22篇 |
1973年 | 22篇 |
排序方式: 共有3452条查询结果,搜索用时 31 毫秒
1.
Potential Analysis - In the present paper, we are going to show that outside a slim set in the sense of Malliavin (or quasi-surely), the signature path (which consists of iterated path integrals in... 相似文献
2.
Letters in Mathematical Physics - We consider the dynamical properties of Quantum Walks defined on the d-dimensional cubic lattice, or the homogeneous tree of coordination number 2d, with... 相似文献
3.
4.
5.
6.
Joachim Loup Uttam Dhawa Fabio Pesciaioli Joanna Wencel‐Delord Lutz Ackermann 《Angewandte Chemie (International ed. in English)》2019,58(37):12803-12818
Molecular syntheses largely rely on time‐ and labour‐intensive prefunctionalization strategies. In contrast, C?H activation represents an increasingly powerful approach that avoids lengthy syntheses of prefunctionalized substrates, with great potential for drug discovery, the pharmaceutical industry, material sciences, and crop protection, among others. The enantioselective functionalization of omnipresent C?H bonds has emerged as a transformative tool for the step‐ and atom‐economical generation of chiral molecular complexity. However, this rapidly growing research area remains dominated by noble transition metals, prominently featuring toxic palladium, iridium and rhodium catalysts. Indeed, despite significant achievements, the use of inexpensive and sustainable 3d metals in asymmetric C?H activations is still clearly in its infancy. Herein, we discuss the remarkable recent progress in enantioselective transformations via organometallic C?H activation by 3d base metals up to April 2019. 相似文献
7.
Mathematical Programming - The aim of this paper is to show that every representative function of a maximally monotone operator is the Fitzpatrick transform of a bifunction corresponding to the... 相似文献
8.
9.
10.
Kapil Shyam Lokare Nicolas Frank Beatrice Braun‐Cula Itziar Goikoetxea Joachim Sauer Christian Limberg 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2016,128(40):12513-12517
To gain molecular level insights into the properties of certain functions and units of extended oxides/hydroxides, suitable molecular model compounds are needed. As an attractive route to access such compounds the trapping of early intermediates during the hydrolysis of suitable precursor compounds with the aid of stabilizing ligands is conceivable, which was tested for the aluminum(III)/water system. Indeed, trisilanols proved suitable trapping reagents: their presence during the hydrolysis of AliBu2H in dependence on the amount of water used allowed for the isolation of tri‐ and octanuclear aluminum hydroxide cluster complexes [Al3(μ2‐OH)3(THF)3(PhSi(OSiPh2O)3)2] ( 1 ) and [Al8(μ3‐OH)2(μ2‐OH)10(THF)3(p‐anisylSi(OSiPh2O)3)4] ( 2 ). 1 can be regarded as the Al(OH)3 cyclic trimer, where six protons have been replaced by silyl residues. While 2 features a unique [Al8(μ3‐OH)2(μ2‐OH)10]12+ core. In contrast to most other known aggregates of this type, 1 and 2 can be readily prepared at reasonable scales, dissolve in common solvents, and retain an intact framework even in the presence of excessive amounts of water. This finding paves the way to future research addressing the reactivity of the individual functional groups. 相似文献