全文获取类型
收费全文 | 275928篇 |
免费 | 3495篇 |
国内免费 | 1452篇 |
专业分类
化学 | 126232篇 |
晶体学 | 4429篇 |
力学 | 14708篇 |
综合类 | 68篇 |
数学 | 44686篇 |
物理学 | 90752篇 |
出版年
2021年 | 1537篇 |
2020年 | 1736篇 |
2019年 | 1872篇 |
2018年 | 10964篇 |
2017年 | 11864篇 |
2016年 | 7591篇 |
2015年 | 3155篇 |
2014年 | 3690篇 |
2013年 | 8415篇 |
2012年 | 10688篇 |
2011年 | 19853篇 |
2010年 | 12577篇 |
2009年 | 12618篇 |
2008年 | 17509篇 |
2007年 | 20780篇 |
2006年 | 6765篇 |
2005年 | 12440篇 |
2004年 | 8740篇 |
2003年 | 8182篇 |
2002年 | 6058篇 |
2001年 | 5561篇 |
2000年 | 4355篇 |
1999年 | 3187篇 |
1998年 | 2702篇 |
1997年 | 2571篇 |
1996年 | 2577篇 |
1995年 | 2356篇 |
1994年 | 2303篇 |
1993年 | 2191篇 |
1992年 | 2460篇 |
1991年 | 2389篇 |
1990年 | 2341篇 |
1989年 | 2260篇 |
1988年 | 2252篇 |
1987年 | 2242篇 |
1986年 | 2132篇 |
1985年 | 2742篇 |
1984年 | 2806篇 |
1983年 | 2490篇 |
1982年 | 2597篇 |
1981年 | 2398篇 |
1980年 | 2385篇 |
1979年 | 2536篇 |
1978年 | 2573篇 |
1977年 | 2415篇 |
1976年 | 2505篇 |
1975年 | 2413篇 |
1974年 | 2376篇 |
1973年 | 2592篇 |
1972年 | 1661篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Galkina E. G. Zaspel C. E. Ivanov B. A. Kulagin N. E. Lerman L. M. 《JETP Letters》2019,110(7):481-486
JETP Letters - The motion of domain walls in GdFeCo-type ferrimagnets near the point of compensation of sublattice spins s1 and s2, when the effects of the exchange increase in the limiting wall... 相似文献
62.
J. Conrad J. Cohen-Tanugi L. E. Strigari 《Journal of Experimental and Theoretical Physics》2015,121(6):1104-1135
The launch of the gamma-ray telescope Fermi Large Area Telescope (Fermi-LAT) started a pivotal period in indirect detection of dark matter. By outperforming expectations, for the first time a robust and stringent test of the paradigm of weakly interacting massive particles (WIMPs) is within reach. In this paper, we discuss astrophysical targets for WIMP detection and the challenges they present, review the analysis tools which have been employed to tackle these challenges, and summarize the status of constraints on and the claimed detections in the WIMP parameter space. Methods and results will be discussed in comparison to Imaging Air Cherenkov Telescopes. We also provide an outlook on short term and longer term developments. 相似文献
63.
64.
Jigneshkumar P. Patel Zou Guo Xiang Shaw Ling Hsu Andrew B. Schoch Sena Ada Carleen Dean Matsumoto 《Journal of Polymer Science.Polymer Physics》2015,53(21):1519-1526
A uniform dispersion of reactants is necessary to achieve a complete reaction involving multicomponents. In this study, we have examined the role of plasticizer in the reaction of two seemingly unlikely reactants: a highly crystalline hexamethylenetetramine (HMTA) and a strongly hydrogen bonded phenol formaldehyde resin. By combining information from NMR, infrared spectroscopy and differential scanning calorimetry, we were able to determine the role of specific intermolecular interactions necessary for the plasticizer to dissolve the highly crystalline HMTA and to plasticize the phenol formaldehyde resin in this crosslinking reaction. The presence of the plasticizer increased the segmental mobility, disrupted the hydrogen bonded matrix, and freed the hydroxyl units, which further increased the solubility of the HMTA. Both the endothermic and exothermic transitions are accounted for in the calorimetric data obtained. For the first time, it is possible to obtain the effective molar ratio of each component needed to complete the crosslinking reaction efficiently. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 1519–1526 相似文献
65.
S. V. Panin I. V. Vlasov V. P. Sergeev B. B. Ovechkin P. O. Marushchak Sunder Ramasubbu P. S. Lyubutin V. V. Titkov 《Physical Mesomechanics》2015,18(3):261-272
The structure and properties of 12Cr1MoV steel irradiated with a zirconium ion beam were studied by optical microscopy, scanning electron microscopy, and micro- and nanoindentation. It is shown that the modification covers the entire cross-section of the irradiated specimens to a depth of 1 mm. The data on irradiation-induced structural changes are used to interpret the changes in mechanical properties of the irradiated specimens under static and cyclic loading. Particular attention is given to analysis of strain estimation by the digital image correlation method. 相似文献
66.
67.
68.
69.
70.
Kinetics and Catalysis - Boron and barium were employed as dopants for the VMgO system. The catalysts were characterized by ICP-OES, BET, IR, powder XRD, EDX, TPR-H2, TPD-NH3, XPS, and 51V MAS NMR.... 相似文献