全文获取类型
收费全文 | 16430篇 |
免费 | 268篇 |
国内免费 | 76篇 |
专业分类
化学 | 6120篇 |
晶体学 | 363篇 |
力学 | 1013篇 |
综合类 | 3篇 |
数学 | 1557篇 |
物理学 | 7718篇 |
出版年
2023年 | 69篇 |
2022年 | 209篇 |
2021年 | 180篇 |
2020年 | 100篇 |
2019年 | 129篇 |
2018年 | 224篇 |
2017年 | 193篇 |
2016年 | 308篇 |
2015年 | 216篇 |
2014年 | 366篇 |
2013年 | 729篇 |
2012年 | 927篇 |
2011年 | 1188篇 |
2010年 | 848篇 |
2009年 | 821篇 |
2008年 | 937篇 |
2007年 | 940篇 |
2006年 | 953篇 |
2005年 | 762篇 |
2004年 | 671篇 |
2003年 | 525篇 |
2002年 | 496篇 |
2001年 | 913篇 |
2000年 | 611篇 |
1999年 | 503篇 |
1998年 | 333篇 |
1997年 | 345篇 |
1996年 | 265篇 |
1995年 | 222篇 |
1994年 | 212篇 |
1993年 | 168篇 |
1992年 | 182篇 |
1991年 | 163篇 |
1990年 | 146篇 |
1989年 | 128篇 |
1988年 | 100篇 |
1987年 | 92篇 |
1986年 | 78篇 |
1985年 | 82篇 |
1984年 | 58篇 |
1983年 | 42篇 |
1982年 | 30篇 |
1981年 | 34篇 |
1980年 | 22篇 |
1978年 | 24篇 |
1977年 | 24篇 |
1976年 | 33篇 |
1975年 | 28篇 |
1974年 | 25篇 |
1973年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Experimental Mechanics - Identification of impact force is essential for various engineering applications, such as performance evaluation, design optimisation, noise suppression, and vibration... 相似文献
992.
Journal of Optimization Theory and Applications - We study the split common fixed point problem for Bregman relatively nonexpansive operators in real reflexive Banach spaces. Using Bregman... 相似文献
993.
Experimental Mechanics - Background: Experimental modelling techniques are still rare for composite structures under complex thermal environments. Objective: In this paper, by taking a... 相似文献
994.
Nonlinear Dynamics - Aiming to isolate disturbance vibration for heavy machines with low frequency, a novel hydro-pneumatic vibration isolator with high-static and low-dynamic (HSLD) stiffness is... 相似文献
995.
996.
Wang C. Cheng S. Y. Zhao W. W. Yang X. N. Zhou K. Z. Tian J. J. Jiang D. F. Ma P. H. 《Crystallography Reports》2020,65(7):1156-1160
Crystallography Reports - This paper reports on the supramolecular self-assembly of cyclopentano cucurbit[5]uril (CyP5Q[5]), L-phenylalanine (L-Phe), and cadmium ions. The crystal structure is... 相似文献
997.
998.
999.
X. Y. Lai Q. Y. Cai M. S. Zhan 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,53(3):393-396
Many nonlinear quantum phenomena of intense laser-atom
physics can be intuitively explained with the concept of trajectory.
In this paper, Bohmian mechanics (BM) is introduced to study a
multiphoton process of atoms interacting with the intense laser
field: above-threshold ionization (ATI). Quantum trajectory of an
atomic electron in intense laser field is obtained from the
Bohm-Newton equation first and then the energy of the photoelectron
is gained from its trajectory. With energies of an ensemble of
photoelectrons, we obtain the ATI spectrum which is consistent with
the previous theoretical and experimental results. Comparing BM with
the classical trajectory Monte-Carlo method, we conclude that
quantum potential may play a key role to reproduce the spectrum of
ATI. Our work may present a new approach to understanding quantum
phenomena in intense laser-atom physics with the image of
trajectory. 相似文献
1000.
Khizar-ul-Haq M.A. Khan Z.L. Zhang X.W. Zhang J.M. Wei Jun Li 《Journal of luminescence》2009,129(10):1158-1162
Blue organic light-emitting devices based on wide bandgap host material, 2-(t-butyl)-9, 10-di-(2-naphthyl) anthracene (TBADN), blue fluorescent styrylamine dopant, p-bis(p-N,N-diphenyl-amino-styryl)benzene (DSA-Ph) have been realized by using molybdenum oxide (MoO3) as a buffer layer and 4,7-diphenyl-1,10-phenanthroline (BPhen) as the ETL. The typical device structure used was glass substrate/ITO/MoO3 (5 nm)/NPB (30 nm)/[TBADN: DSA-Ph (3 wt%)](35 nm)/BPhen (12 nm)/LiF (0.8 nm)/Al (100 nm). It was found that the MoO3∥BPhen-based device shows the lowest driving voltage and highest power efficiency among the referenced devices. At the current density of 20 mA/cm2, its driving voltage and power efficiency are 5.4 V and 4.7 Lm/W, respectively, which is independently reduced 46%, and improved 74% compared with those the m-MTDATA∥Alq3 is based on, respectively. The J-V curves of ‘hole-only’ devices reveal that a small hole injection barrier between MoO3∥NPB leads to a strong hole injection, resulting low driving voltage and high power efficiency. The results strongly indicate that carrier injection ability and balance shows a key significance in OLED performance. 相似文献