全文获取类型
收费全文 | 14214篇 |
免费 | 3043篇 |
国内免费 | 4511篇 |
专业分类
化学 | 10761篇 |
晶体学 | 596篇 |
力学 | 971篇 |
综合类 | 450篇 |
数学 | 1795篇 |
物理学 | 7195篇 |
出版年
2024年 | 31篇 |
2023年 | 166篇 |
2022年 | 454篇 |
2021年 | 472篇 |
2020年 | 554篇 |
2019年 | 554篇 |
2018年 | 494篇 |
2017年 | 636篇 |
2016年 | 648篇 |
2015年 | 767篇 |
2014年 | 894篇 |
2013年 | 1202篇 |
2012年 | 1252篇 |
2011年 | 1322篇 |
2010年 | 1190篇 |
2009年 | 1277篇 |
2008年 | 1365篇 |
2007年 | 1134篇 |
2006年 | 1127篇 |
2005年 | 1021篇 |
2004年 | 781篇 |
2003年 | 572篇 |
2002年 | 572篇 |
2001年 | 598篇 |
2000年 | 592篇 |
1999年 | 349篇 |
1998年 | 198篇 |
1997年 | 172篇 |
1996年 | 156篇 |
1995年 | 163篇 |
1994年 | 128篇 |
1993年 | 133篇 |
1992年 | 125篇 |
1991年 | 90篇 |
1990年 | 104篇 |
1989年 | 78篇 |
1988年 | 54篇 |
1987年 | 61篇 |
1986年 | 49篇 |
1985年 | 41篇 |
1984年 | 33篇 |
1983年 | 31篇 |
1982年 | 16篇 |
1981年 | 19篇 |
1980年 | 20篇 |
1979年 | 18篇 |
1978年 | 12篇 |
1966年 | 7篇 |
1965年 | 7篇 |
1964年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Yong LU Hong WANG Ye LIU Ming Yuan HE 《中国化学快报》2006,17(10):1397-1400
Recently, miniature H2 generator to power fuel cells for portable/micro electronic devices and passenger propulsion has been the focus of intense research activities1-3. One of the strategies is to find simple CO-free H2 production with novel microreactor… 相似文献
83.
Suppression of Chaos and Phase Locking in Two Coupled Nonidentical Neurons under Periodic Input
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dynamical behaviour of two coupled neurons with at least one of them being chaotic is presented. Bifurcation diagrams and Lyapunov exponents are calculated to diagnose the dynamical behaviour of the coupled neurons with the increasing coupling strength. It is found that when the coupling strength increases, a chaotic neuron can be controlled by the coupling between neurons. At the same time, phase locking is studied by the maxima of the differences of instantaneous phases and average frequencies between two coupled neurons, and the inherent connection of phase locking and the suppression of chaos is formulated. It is observed that the onset of phase locking is closely related to the suppression of chaos. Finally, a way for suppression of chaos in two coupled nonidentical neurons under periodic input is suggested. 相似文献
84.
高固体分羟基丙烯酸树脂的合成 总被引:1,自引:0,他引:1
以过氧化二苯甲酰(BPO)/过氧化二异丙苯(DCP)(质量比为2:3)为复合引发剂,二甲苯为溶剂,选用适量含羟基单体和分子量调节剂,以减缓树脂合成聚合反应中的自动加速现象,合成了分子量为3000-4000,多分散性指数d〈2的高固体分羟基丙烯酸树脂.该树脂与缩二脲多异氰酸酯(HDI)的配漆实验证明,所得漆膜鲜映性好、丰满度高、色泽好、雾影值低、综合性能较好. 相似文献
85.
Jin Hu Gang Liu Jixiu Zhang Lingchao Kong Weidong Fei 《Applied Surface Science》2006,253(5):2792-2795
The microstructure of a laser treated Al18B4O33w/2024Al composite has been investigated using transmission electron microscope (TEM), low-angle (glancing angle) X-ray diffraction (XRD) techniques. Various surface microstructures were observed in the laser treated composite. The Al18B4O33 whisker on the surface of the composite was decomposed during laser surface melting, various decomposition products were studied in the laser treated composite. Eutectic phases and the precipitation in the matrix of the composite with laser-treated were observed. The main phases detected in the molten zone were aluminum and decomposition products Al2O3. The effect of laser treatment on the hardness of the composite was also examined. A surface hardness of 400 Hv was noted. 相似文献
86.
87.
标度系统一致性矩阵容量的计算方法 总被引:4,自引:0,他引:4
吕跃进 《数学的实践与认识》2003,33(9):102-107
本文研究正互反矩阵的变换性质 ,提出一种保持正互反矩阵一致性程度的等价分类 ,为计算各种标度系统下的一致矩阵容量提供了计算方法 相似文献
88.
89.
Qingfa Wang Li Wang Yaquan Wang Fei He Zhenhua Li Zhentao Mi 《Reaction Kinetics and Catalysis Letters》2004,81(2):297-304
Deactivated palladium catalysts in the hydrogenation of anthraquinione were regenerated with ethanol, nitric acid, hydrogen
peroxide, boiling water and steam, respectively. The deactivated and regenerated catalysts were characterized by XPS, ICP,
TG, FTIR, TPD, XRD, etc., and studied in the hydrogenation of anthraquinone. The results showed that the main cause of catalyst deactivation is the
coverage of the active component by deposits. The treatments by hydrogen peroxide and boiling water can effectively regenerate
the deactivated catalysts.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
90.