全文获取类型
收费全文 | 18871篇 |
免费 | 3192篇 |
国内免费 | 3276篇 |
专业分类
化学 | 14145篇 |
晶体学 | 317篇 |
力学 | 1082篇 |
综合类 | 320篇 |
数学 | 2571篇 |
物理学 | 6904篇 |
出版年
2024年 | 35篇 |
2023年 | 326篇 |
2022年 | 571篇 |
2021年 | 655篇 |
2020年 | 757篇 |
2019年 | 729篇 |
2018年 | 630篇 |
2017年 | 664篇 |
2016年 | 872篇 |
2015年 | 939篇 |
2014年 | 1145篇 |
2013年 | 1408篇 |
2012年 | 1697篇 |
2011年 | 1839篇 |
2010年 | 1379篇 |
2009年 | 1245篇 |
2008年 | 1412篇 |
2007年 | 1241篇 |
2006年 | 1133篇 |
2005年 | 922篇 |
2004年 | 780篇 |
2003年 | 716篇 |
2002年 | 788篇 |
2001年 | 617篇 |
2000年 | 414篇 |
1999年 | 402篇 |
1998年 | 247篇 |
1997年 | 205篇 |
1996年 | 239篇 |
1995年 | 194篇 |
1994年 | 177篇 |
1993年 | 147篇 |
1992年 | 135篇 |
1991年 | 118篇 |
1990年 | 95篇 |
1989年 | 84篇 |
1988年 | 50篇 |
1987年 | 48篇 |
1986年 | 44篇 |
1985年 | 53篇 |
1984年 | 22篇 |
1983年 | 15篇 |
1982年 | 14篇 |
1981年 | 12篇 |
1980年 | 8篇 |
1963年 | 7篇 |
1959年 | 12篇 |
1958年 | 11篇 |
1957年 | 16篇 |
1956年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 453 毫秒
101.
The fission barrier for ^240pu is investigated beyond the second saddle point in the potentiM energy surface by the constrained relativistic mean field method with the newly proposed parameter set PK1. The microscopic correction for the centre-of-mass motion is essentiM to provide the correct potential energy surface. The shell effects that stabilize the nuclei against the fission is also investigated by the Strutinsky method. The shapes for the ground state, fission isomer and saddle-points, etc, are studied in detail. 相似文献
102.
Quantum gravity can modify the usual energy-momentum dispersion relation. We provide evidence for the argument that the modified dispersion relation is constrained by the black hole thermodynamics, for consistency of quantum gravity. 相似文献
103.
104.
Hong Ming ZHANG Xian Hong WANG Xiao Jiang ZHAO Ji LI Fo Song WANG 《中国化学快报》2006,17(4):437-440
A novel method for the preparation of oligothiophene molecular wires is described via a bi-directional solid-phase synthesis. Using an alternating sequence of bromination and Stille coupling reactions, oligomers were obtained up to the heptamer in excellent yield and purity. 相似文献
105.
106.
107.
用射频磁控溅射法在80℃衬底温度下制备出MgxZn1-xO(x=0.16)薄膜,用X射线衍射(XRD)、光致发光(PL)和透射谱研究了退火温度对MgxZn1-xO薄膜结构和光学性质的影响.测量结果显示,MgxZn1-xO薄膜为单相六角纤锌矿结构,并且具有沿c轴的择优取向;随着退火温度的升高,(002)XRD峰强度、平均晶粒尺寸和紫外PL峰强度增大,(002)XRD峰半高宽(F
关键词:
xZn1-xO薄膜')" href="#">MgxZn1-xO薄膜
射频磁控溅射
退火 相似文献
108.
Kyung Hwa Hong Jong Lyoul Park In Hwan Sul Ji Ho Youk Tae Jin Kang 《Journal of Polymer Science.Polymer Physics》2006,44(17):2468-2474
Polyvinyl alcohol (PVA) nanofibers containing Ag nanoparticles were prepared by electrospinning PVA/silver nitrate (AgNO3) aqueous solutions, followed by short heat treatment, and their antimicrobial activity was investigated for wound dressing applications. Since PVA is a water soluble and biocompatible polymer, it is one of the best materials for the preparation of wound dressing nanofibers. After heat treatment at 155 °C for 3 min, the PVA/AgNO3 nanofibers became insoluble, while the Ag+ ions therein were reduced so as to produce a large number of Ag nanoparticles situated preferentially on their surface. The residual Ag+ ions were reduced by subsequent UV irradiation for 3 h. The average diameter of the Ag nanoparticles after the heat treatment was 5.9 nm and this value increased slightly to 6.3 nm after UV irradiation. It was found that most of the Ag+ ions were reduced by the simple heat treatment. The PVA nanofibers containing Ag nanoparticles showed very strong antimicrobial activity. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2468–2474, 2006 相似文献
109.
Jiří Rais 《Journal of Radioanalytical and Nuclear Chemistry》2006,270(3):709-710
Dr. Miroslav Kyrš, DrSc. passed away prematurely and unexpectedly in August 2006 at age of 75. He was a leading person of
the Czech radiochemistry during the second half of the 20th century and his results have of world-wide impact. His diligence,
intelligence and permanent activity led him to be at first a laboratory chief and subsequently for about 25 years to be a
chief of the Radiochemical Department of Czech Nuclear Research Institute (NRI) at Řež near Prague. 相似文献
110.