全文获取类型
收费全文 | 3488篇 |
免费 | 182篇 |
国内免费 | 52篇 |
专业分类
化学 | 2281篇 |
晶体学 | 14篇 |
力学 | 85篇 |
数学 | 504篇 |
物理学 | 838篇 |
出版年
2024年 | 3篇 |
2023年 | 23篇 |
2022年 | 32篇 |
2021年 | 112篇 |
2020年 | 101篇 |
2019年 | 154篇 |
2018年 | 130篇 |
2017年 | 118篇 |
2016年 | 170篇 |
2015年 | 130篇 |
2014年 | 165篇 |
2013年 | 221篇 |
2012年 | 304篇 |
2011年 | 327篇 |
2010年 | 170篇 |
2009年 | 177篇 |
2008年 | 255篇 |
2007年 | 238篇 |
2006年 | 207篇 |
2005年 | 185篇 |
2004年 | 141篇 |
2003年 | 92篇 |
2002年 | 90篇 |
2001年 | 25篇 |
2000年 | 24篇 |
1999年 | 23篇 |
1998年 | 25篇 |
1997年 | 24篇 |
1996年 | 18篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有3722条查询结果,搜索用时 31 毫秒
1.
Prants Sergey V. Kon’kov Leonid E. Didov Aleksandr A. 《Journal of Russian Laser Research》2021,42(5):558-568
Journal of Russian Laser Research - We examine the coherent dynamics of cold atoms in a three-dimensional (3D) optical lattice (OL) without interference between counter-propagating laser beams. The... 相似文献
2.
Zherikova Kseniya V. Verevkin Sergey P. 《Journal of Thermal Analysis and Calorimetry》2019,138(6):4045-4059
Journal of Thermal Analysis and Calorimetry - Experimental thermodynamic properties of halogenosubstituted benzoic acids have been evaluated with the help of complementary in silico methods. The... 相似文献
3.
The reactions of 3-tert-butyl-7-R1-8-R2-pyrazolo[5,1-c][1,2,4]triazines (R1 = H, Br; R2 = Me, n-Bu) with N-bromosuccinimide in the presence of R3CO2H (R3 = Me, t-Bu, Ph) afforded novel diastereomerically pure 3-tert-butyl-7-R1-8-R2-3,4-dihydropyrazolo[5,1-c][1,2,4]triazine-3,4-diyl dicarboxylates. The structures of the isolated products were established on the basis of IR, 1H, 13C, 2D NOESY NMR, high resolution mass spectrometry and X-ray single-crystal analysis. The steric and mechanistic origins of the observed regio- and stereoselectivity were also discussed. 相似文献
4.
5.
Sandugash K. Kodanova Moldir K. Issanova Tlekkabul S. Ramazanov Askar K. Khikmetov Sergey A. Maiorov 《等离子体物理论文集》2019,59(6)
In this paper, the relaxation properties of a fully ionized, hot, ideal plasma have been studied using the molecular dynamics method. As an example, the classical problem of equalization of the electron and ion temperatures for various mass ratios is considered, the relaxation times for temperatures is determined, and the influence of the number of particles and the type of boundary conditions on the simulation results is studied. The simulation results are compared with the available theoretical results. 相似文献
6.
Monika Kořenková Dr. Ing. Martin Hejda Prof. Milan Erben Dr. Ing. Robert Jirásko Prof. Dr. Roman Jambor Prof. Aleš Růžička Dr. Elena Rychagova Prof. Sergey Ketkov Prof. Libor Dostál 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(56):12884-12888
The reaction of N,C,N-chelated stibinidene ArSb ( 1 ) (Ar=C6H3-2,6-(CH=NtBu)2) with selected N-alkyl/aryl-maleimides RN(C(O)CH)2 (R=Me, tBu, Ph) gave the addition products with bridged bicyclic [2.2.1] structure containing an antimony atom at the bridgehead position, fused with a 6-membered benzene and a 5-membered N-alkyl/aryl-pyrrolidine ring. These compounds were completely characterized. More importantly, additional studies showed that these reactions are reversible in solution, thereby representing an unprecedented reversible activation of a C=C bond by an antimony(I) compound. 相似文献
7.
Sergey I. Lopatin Sergey M. Shugurov Andrej I. Panin 《Journal of mass spectrometry : JMS》2019,54(6):507-519
Gaseous CePO2 has been identified by Knudsen effusion mass spectrometry during vaporization of CeO2 and magnesium diphosphate from tungsten double, two‐temperature effusion cell. Structure and molecular parameters of gaseous cerium phosphate under study were determined using quantum chemical calculations. On the basis of equilibrium constants measured for gas‐phase reaction, standard formation enthalpy of CePO2 was determined to be ?508 ± 41 kJ ? mol?1 at the temperature 298 K. 相似文献
8.
9.
10.
Bumagin Nikolay A. Petkevich Sergey K. Kletskov Alexey V. Alekseyev Roman S. Potkin Vladimir I. 《Chemistry of Heterocyclic Compounds》2019,55(6):508-516
Chemistry of Heterocyclic Compounds - N-(4,6-Dimethylpyrimidin-2-yl)-5-phenylisoxazole-3-carboxamide was used as a ligand for obtaining bimetallic boron-containing heterogeneous catalysts... 相似文献