全文获取类型
收费全文 | 14909篇 |
免费 | 1423篇 |
国内免费 | 740篇 |
专业分类
化学 | 9897篇 |
晶体学 | 152篇 |
力学 | 538篇 |
综合类 | 49篇 |
数学 | 2179篇 |
物理学 | 4257篇 |
出版年
2023年 | 201篇 |
2022年 | 280篇 |
2021年 | 332篇 |
2020年 | 394篇 |
2019年 | 372篇 |
2018年 | 391篇 |
2017年 | 356篇 |
2016年 | 633篇 |
2015年 | 518篇 |
2014年 | 644篇 |
2013年 | 1131篇 |
2012年 | 1126篇 |
2011年 | 1234篇 |
2010年 | 715篇 |
2009年 | 689篇 |
2008年 | 921篇 |
2007年 | 899篇 |
2006年 | 793篇 |
2005年 | 675篇 |
2004年 | 495篇 |
2003年 | 345篇 |
2002年 | 355篇 |
2001年 | 284篇 |
2000年 | 257篇 |
1999年 | 213篇 |
1998年 | 193篇 |
1997年 | 160篇 |
1996年 | 154篇 |
1995年 | 182篇 |
1994年 | 147篇 |
1993年 | 131篇 |
1992年 | 132篇 |
1991年 | 112篇 |
1990年 | 114篇 |
1989年 | 85篇 |
1988年 | 92篇 |
1987年 | 81篇 |
1986年 | 75篇 |
1985年 | 91篇 |
1984年 | 89篇 |
1983年 | 73篇 |
1982年 | 81篇 |
1981年 | 55篇 |
1980年 | 60篇 |
1979年 | 54篇 |
1978年 | 78篇 |
1977年 | 47篇 |
1976年 | 59篇 |
1975年 | 47篇 |
1974年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Wei-yi SU~ 《中国科学A辑(英文版)》2007,50(7):1005-1014
The Lipschitz class Lipαon a local field K is defined in this note,and the equivalent relationship between the Lipschitz class Lipαand the Holder type space C~α(K)is proved.Then,those important characteristics on the Euclidean space R~n and the local field K are compared,so that one may interpret the essential differences between the analyses on R~n and K.Finally,the Cantor type fractal functionθ(x)is showed in the Lipschitz class Lip(m,K),m<(ln 2/ln 3). 相似文献
62.
用解偏振光强法和差示扫描量热法(DSC)分别研究了聚甲醛和聚甲醛助剂P的等温结晶动力学和非等温结晶动力学。探讨了助剂P对聚甲醛的结晶成核作用。 相似文献
63.
The kinetic behaviour of aluminum naphthenate/benzene system in the process of gelation and degradation was systematically studied. The results obtained from the kinetic experiments indicated that the gelation stage was in accordance with a kinetic model of an auto-catalytic first-order reaction, and the degradation stage was a simple first-order reaction. The rate constants in these two stages at various temperaturs were measured. And the determined apparent activation energies for the gelation stage and for the degradation stage are 27.5±2.0 and 37.7±2.3 kJ/mol, respectively. 相似文献
64.
65.
V. V. Panić A. B. Dekanski S. K. Milonjić V. B. Mišković-Stanković B. Ž. Nikolić 《Russian Journal of Electrochemistry》2006,42(10):1055-1060
Electrocatalytic properties of RuO2/Ti anode with different coating masses, which are prepared by the alkoxide sol-gel procedure, are investigated in chlorine
and oxygen evolution reactions by polarization measurements and electrochemical impedance spectroscopy in H2SO4 and NaCl electrolytes. According to polarization measurements, the activity of anodes at overpotentials below 100 mV is independent
of coating mass. However, impedance measurements above 100 mV reveal changes in the activity of anodes in chlorine evolution
reaction for different coating masses. The diffusion limitations related to the evolved chlorine are registered in low-frequency
domain at 1.10 V (SCE), diminishing with the increase in potential to the 1.15 V (SCE). The observed impedance behavior is
discussed with respect to the activity model for activated titanium anodes in chlorine evolution reaction involving formation
of gas channels within porous coating structure. Gas channels enhance the mass transfer rate similarly to the forced convection,
which also increases the activity of anode. This is more pronounced for the anode of greater coating mass due to its more
compact surface structure. The more compact structure appears to be beneficial for gas channels formation.
Published in Russian in Elektrokhimiya, 2006, Vol. 42, No. 10, pp. 1173–1179.
The text was submitted by the authors in English. 相似文献
66.
G. Bilalbegović 《Zeitschrift für Physik B Condensed Matter》1987,69(1):117-120
The interfacial tension of a three-dimensional Ising model in the whole temperature region is calculated by the real-space renormalisation group methods. The cumulant and the finite-cluster approximations with different projection rules are used. The results are consistent with expected low-temperature and global behaviour of the interfacial tension in the three-dimensional model. 相似文献
67.
68.
Wei Gang SU Huai Jie ZHONG 《数学学报(英文版)》2006,22(2):515-522
This paper introduces the concept of the generalized Riesz operators and the concept of the generalized West decomposition of a general operator which generalizes the definition of the West decomposition of Riesz operators, and proves that the following three statements are equivalent on a general Banach space:
(a) Every generalized Riesz operator has the generalized West decomposition;
(b) Every operator makes strong Stampfli theorem true; Every operator has Apostol's compact correction. 相似文献
69.
Ching-Cherng Sun You-Nian Lin Shih-Po Yeh Wei-Chia Su Yuh Ouyang 《Optics & Laser Technology》2002,34(7):523-526
High longitudinal selectivity of the shifting multiplexing with spherical reference wave is proposed and demonstrated. A simplified method based on wave optics is used for calculating the selectivity, and the result fits well the experimental measurement. Under the paraxial condition, a simple formula for the longitudinal selectivity is introduced. With use of an object lens with effective NA=0.817, we obtain that an FWHM of selectivity is as small as 1 μm. 相似文献
70.