全文获取类型
收费全文 | 104049篇 |
免费 | 6685篇 |
国内免费 | 5503篇 |
专业分类
化学 | 60144篇 |
晶体学 | 1508篇 |
力学 | 5875篇 |
综合类 | 419篇 |
数学 | 12497篇 |
物理学 | 35794篇 |
出版年
2023年 | 798篇 |
2022年 | 1923篇 |
2021年 | 2207篇 |
2020年 | 2555篇 |
2019年 | 2770篇 |
2018年 | 3091篇 |
2017年 | 3078篇 |
2016年 | 3795篇 |
2015年 | 2716篇 |
2014年 | 3836篇 |
2013年 | 5416篇 |
2012年 | 5646篇 |
2011年 | 5944篇 |
2010年 | 4711篇 |
2009年 | 4711篇 |
2008年 | 4882篇 |
2007年 | 4525篇 |
2006年 | 4081篇 |
2005年 | 3625篇 |
2004年 | 3230篇 |
2003年 | 2851篇 |
2002年 | 2952篇 |
2001年 | 2641篇 |
2000年 | 2049篇 |
1999年 | 1674篇 |
1998年 | 1563篇 |
1997年 | 1364篇 |
1996年 | 1340篇 |
1995年 | 1122篇 |
1994年 | 1176篇 |
1993年 | 1116篇 |
1992年 | 1070篇 |
1991年 | 1138篇 |
1990年 | 1129篇 |
1989年 | 1047篇 |
1988年 | 919篇 |
1987年 | 916篇 |
1986年 | 883篇 |
1985年 | 927篇 |
1984年 | 917篇 |
1983年 | 827篇 |
1982年 | 802篇 |
1979年 | 801篇 |
1978年 | 812篇 |
1977年 | 806篇 |
1976年 | 919篇 |
1975年 | 812篇 |
1974年 | 844篇 |
1973年 | 847篇 |
1972年 | 752篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
121.
Optics and Spectroscopy - The relationship between the parameters of quadripoles (mirrors, for example) ensuring the fulfillment of the energy conservation law are considered. Apart from the... 相似文献
122.
123.
A. L. Apanasenko A. V. Kuznichenko Yu. B. Govyadovskii V. G. Yakunin 《Journal of Applied Spectroscopy》1991,54(3):271-276
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 54, No. 3, pp. 438–444, March, 1991. 相似文献
124.
Yu. K. Voron'ko A. B. Kudryavtsev V. V. Osiko E. V. Sorokin 《Journal of Applied Spectroscopy》1991,55(4):953-957
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 55, No. 4, pp. 535–540, October, 1991. 相似文献
125.
126.
文章提出了大学研究性物理实验与创新心理品质培养的主题,介绍了大学研究性物理实验的特点,论述了大学研究性物理实验对大学生创新心理品质的影响。 相似文献
127.
Qipeng Guo Fei Chen Ke Wang Ling Chen 《Journal of Polymer Science.Polymer Physics》2006,44(21):3042-3052
An amphiphilic poly(ethylene oxide)‐block‐poly(dimethylsiloxane) (PEO–PDMS) diblock copolymer was used to template a bisphenol A type epoxy resin (ER); nanostructured thermoset blends of ER and PEO–PDMS were prepared with 4,4′‐methylenedianiline (MDA) as the curing agent. The phase behavior, crystallization, hydrogen‐bonding interactions, and nanoscale structures were investigated with differential scanning calorimetry, Fourier transform infrared spectroscopy, transmission electron microscopy, and small‐angle X‐ray scattering. The uncured ER was miscible with the poly(ethylene oxide) block of PEO–PDMS, and the uncured blends were not macroscopically phase‐separated. Macroscopic phase separation took place in the MDA‐cured ER/PEO–PDMS blends containing 60–80 wt % PEO–PDMS diblock copolymer. However, the composition‐dependent nanostructures were formed in the cured blends with 10–50 wt % PEO–PDMS, which did not show macroscopic phase separation. The poly(dimethylsiloxane) microdomains with sizes of 10–20 nm were dispersed in a continuous ER‐rich phase; the average distance between the neighboring microdomains was in the range of 20–50 nm. The miscibility between the cured ER and the poly(ethylene oxide) block of PEO–PDMS was ascribed to the favorable hydrogen‐bonding interaction. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3042–3052, 2006 相似文献
128.
The excitation of eigen surface waves by tubular electron beams in cylindrical discharge devices is studied. The influence of the wave‐field azimuthal structure on the excitation efficiency and nonlinear stage of the plasmabeam instability is investigated both numerically and analytically. Analytical expressions for the saturation amplitude and excitation efficiency of the wave under study are derived. They are found to agree well with results obtained by numerical modelling of the plasma‐beam interaction presented in this paper. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
129.
V. Yu. Baranovskii L. L. Yasina M. V. Motyakin I. I. Aliev S. Shenkov M. Dimitrov N. Lambov A. M. Wasserman 《Polymer Science Series A》2006,48(12):1304-1309
Partially water-swellable polymer networks were synthesized on the basis of poly(acrylic acid) and various macrodiisocyanates. Hydrophilic and hydrophobic local regions were revealed in swollen networks (hydrogels) by means of the spin probe technique. The local mobility in hydrophobic regions depends on the macrodiisocyanate structure; however, it is substantially lower than that in hydrophilic regions for all gels. It was assumed that the presence of hydrophobic and hydrophilic regions and the difference in their local dynamics must have a substantial effect on the pharmacokinetics of release of drugs immobilized in these hydrogels. 相似文献
130.