全文获取类型
收费全文 | 18123篇 |
免费 | 3028篇 |
国内免费 | 2023篇 |
专业分类
化学 | 12718篇 |
晶体学 | 205篇 |
力学 | 1266篇 |
综合类 | 88篇 |
数学 | 1909篇 |
物理学 | 6988篇 |
出版年
2024年 | 63篇 |
2023年 | 385篇 |
2022年 | 674篇 |
2021年 | 685篇 |
2020年 | 710篇 |
2019年 | 679篇 |
2018年 | 628篇 |
2017年 | 565篇 |
2016年 | 955篇 |
2015年 | 849篇 |
2014年 | 1075篇 |
2013年 | 1309篇 |
2012年 | 1653篇 |
2011年 | 1615篇 |
2010年 | 1094篇 |
2009年 | 1024篇 |
2008年 | 1211篇 |
2007年 | 1042篇 |
2006年 | 956篇 |
2005年 | 843篇 |
2004年 | 608篇 |
2003年 | 498篇 |
2002年 | 502篇 |
2001年 | 397篇 |
2000年 | 355篇 |
1999年 | 348篇 |
1998年 | 284篇 |
1997年 | 253篇 |
1996年 | 292篇 |
1995年 | 280篇 |
1994年 | 200篇 |
1993年 | 152篇 |
1992年 | 157篇 |
1991年 | 152篇 |
1990年 | 129篇 |
1989年 | 102篇 |
1988年 | 85篇 |
1987年 | 76篇 |
1986年 | 57篇 |
1985年 | 47篇 |
1984年 | 36篇 |
1983年 | 35篇 |
1982年 | 23篇 |
1981年 | 21篇 |
1980年 | 13篇 |
1978年 | 10篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1968年 | 6篇 |
1957年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
31.
32.
Wenping Deng Gang Xu Lei Wan Anwen Liu Bo Gao Junhe Du Shuiming Hu Yang Chen 《Acta Physico》2008,24(8):1329-1334
Apparatus integrating a Fourier transform-infrared (FT-IR) spectrometer and a mid-infrared difference frequency generation (DFG) laser spectrometer was built for the study of the matrix isolation spectrum in solid molecular hydrogen. A 3-cm-long molecular hydrogen crystal was grown in a liquid-helium Dewar, and its infrared absorption spectrum in the 1-5 μm region was recorded to test the system. The W0(0) (ν=0←0, J=6←0) line around 2410 cm−1 of solid hydrogen was investigated with the DFG laser spectroscopy. High-resolution matrix isolation spectrum of CO2 co-deposited with hydrogen on a BaF2 cold plate at liquid-helium temperature was studied. 相似文献
33.
34.
光照与彩陶俑表面色变关系的实验研究 总被引:1,自引:0,他引:1
本文以秦彩俑表面色彩为研究对象,通过光照实验与色彩变化的色度测量,分析了光照引起彩俑颜料色变的规律,为秦彩俑这一大型重点文物的色彩保护提供了科学理论依据. 相似文献
35.
The goal of this paper is to compute the shape Hessian for a generalized Oseen problem with nonhomogeneous Dirichlet boundary
condition by the velocity method. The incompressibility will be treated by penalty approach. The structure of the shape gradient
and shape Hessian with respect to the shape of the variable domain for a given cost functional are established by an application
of the Lagrangian method with function space embedding technique.
This work was supported by the National Natural Science Fund of China (No. 10371096) for ZM Gao and YC Ma. 相似文献
36.
37.
Trirubidium diyttrium triborate contains zigzag chains of corner‐sharing [Y2O10] dimers. The chains are reinforced by one independent BO3 group and crosslinked by the other two types of BO3 groups to form a three‐dimensional framework. Channels along the [100] direction accommodate the Rb+ cations. 相似文献
38.
Suoyuan Lian Lei Gao Zhenhui Kang Di Wu Yang Lan Lin Xu 《Solid State Communications》2004,132(6):375-378
Single-crystal magnetite nanowires with average diameter of ca. 20 nm and length of up to several micrometers were prepared by a simple alkaline surfactant-free hydrothermal process. The crystallinity, purity, morphology, and structural features of the as-prepared magnetite nanowires were investigated by powder X-ray diffraction, transmission electron microscopy (TEM) and selected area electron diffraction. The composition and length of nanowires depends on the pH, with higher pH favoring longer nanowires composed entirely of Fe3O4. A mechanism for nanowire growth is proposed. 相似文献
39.
40.
Guilin Wen Qing-Guo Wang Chong Lin Xu Han Guangyao Li 《Chaos, solitons, and fractals》2006,29(5):1142-1146
Synchronization under output feedback control with multiple random time delays is studied, using the paradigm in nonlinear physics—Chua’s circuit. Compared with other synchronization control methods, output feedback control with multiple random delay is superior for a realistic synchronization application to secure communications. Sufficient condition for global stability of delay-dependent synchronization is established based on the LMI technique. Numerical simulations fully support the analytical approach, in spite of the random delays. 相似文献