全文获取类型
收费全文 | 2851篇 |
免费 | 106篇 |
国内免费 | 15篇 |
专业分类
化学 | 1819篇 |
晶体学 | 15篇 |
力学 | 123篇 |
数学 | 438篇 |
物理学 | 577篇 |
出版年
2023年 | 28篇 |
2022年 | 19篇 |
2021年 | 54篇 |
2020年 | 60篇 |
2019年 | 62篇 |
2018年 | 41篇 |
2017年 | 32篇 |
2016年 | 73篇 |
2015年 | 69篇 |
2014年 | 62篇 |
2013年 | 123篇 |
2012年 | 159篇 |
2011年 | 190篇 |
2010年 | 93篇 |
2009年 | 75篇 |
2008年 | 174篇 |
2007年 | 158篇 |
2006年 | 182篇 |
2005年 | 141篇 |
2004年 | 80篇 |
2003年 | 82篇 |
2002年 | 57篇 |
2001年 | 51篇 |
2000年 | 28篇 |
1999年 | 30篇 |
1998年 | 36篇 |
1997年 | 30篇 |
1996年 | 33篇 |
1995年 | 27篇 |
1994年 | 24篇 |
1993年 | 25篇 |
1992年 | 29篇 |
1991年 | 29篇 |
1990年 | 26篇 |
1989年 | 20篇 |
1988年 | 22篇 |
1987年 | 27篇 |
1986年 | 32篇 |
1985年 | 25篇 |
1984年 | 26篇 |
1983年 | 19篇 |
1982年 | 20篇 |
1981年 | 33篇 |
1980年 | 35篇 |
1978年 | 30篇 |
1977年 | 31篇 |
1976年 | 26篇 |
1975年 | 23篇 |
1974年 | 22篇 |
1972年 | 16篇 |
排序方式: 共有2972条查询结果,搜索用时 31 毫秒
101.
102.
Journal of Radioanalytical and Nuclear Chemistry - 相似文献
103.
104.
Morgan A. Higgins Christopher R. Maroon Jacob Townsend Xinyi Wang Konstantinos D. Vogiatzis Brian K. Long 《Journal of polymer science. Part A, Polymer chemistry》2020,58(18):2644-2653
Polymeric membranes have shown tremendous promise for the separation of CO2 from flue gas streams. However, few systematic studies have been conducted to better understand the impact that chemical functionalities have on membrane-based gas separation performance. To address this gap, we herein describe the synthesis and gas separation performance of a series of vinyl-addition polynorbornenes bearing various CO2-philic functional groups. To facilitate direct comparison between functional groups, each material was designed to maintain a common polymer backbone. Though the incorporation of CO2-philic moieties within a dense polymeric membrane is frequently hypothesized to enhance CO2 solubility, and thereby increase CO2/N2 selectivity, our results demonstrate that the incorporation of CO2-philic groups onto a common polymer backbone do not necessarily result in increased gas separation performance. Experimental and computational results demonstrate that the incorporation of amidoxime groups onto a polynorbornene backbone increase CO2/N2 selectivity, whereas commonly employed ethereal side chains only increased permeability. 相似文献
105.
106.
Maywald Jacob D. Reiman Adam D. Overstreet Robert E. Johnson Alan W. 《Annals of Operations Research》2019,274(1-2):425-445
Annals of Operations Research - We consider the use of the new C-130J-30 aircraft for long distance (strategic) cargo movement. Currently, only large aircraft, the C-5 and the C-17, are identified... 相似文献
107.
108.
Different methods for the interpretation of linear dichroic spectra of molecules incorporated in uniaxial matrices are discussed. A method based on the combination of both polarized absorption and emission measurements is described for the resolution of absorption and emission spectra into their different polarized components, and for the investigation of molecular distributions in the oriented matrix. The distributions of some planar molecules of different shapes incorporated in stretched polyethylene films are presented. 相似文献
109.
110.
Recent measurements of charge-dependent azimuthal correlations in high-energy heavy-ion collisions have indicated charge-separation signals perpendicular to the reaction plane, and have been related to the chiral magnetic effect(CME). However, the correlation signal is contaminated with the background caused by the collective motion(flow) of the collision system, and an effective approach is needed to remove the flow background from the correlation. We present a method study with simplified Monte Carlo simulations and a multi-phase transport model,and develop a scheme to reveal the true CME signal via event-shape engineering with the flow vector of the particles of interest. 相似文献