全文获取类型
收费全文 | 1487篇 |
免费 | 36篇 |
国内免费 | 9篇 |
专业分类
化学 | 972篇 |
晶体学 | 5篇 |
力学 | 29篇 |
数学 | 200篇 |
物理学 | 326篇 |
出版年
2020年 | 16篇 |
2019年 | 20篇 |
2018年 | 15篇 |
2017年 | 12篇 |
2016年 | 24篇 |
2015年 | 20篇 |
2014年 | 15篇 |
2013年 | 41篇 |
2012年 | 75篇 |
2011年 | 58篇 |
2010年 | 47篇 |
2009年 | 35篇 |
2008年 | 84篇 |
2007年 | 66篇 |
2006年 | 57篇 |
2005年 | 67篇 |
2004年 | 42篇 |
2003年 | 55篇 |
2002年 | 42篇 |
2001年 | 30篇 |
2000年 | 30篇 |
1999年 | 32篇 |
1998年 | 24篇 |
1997年 | 16篇 |
1996年 | 20篇 |
1995年 | 22篇 |
1994年 | 20篇 |
1993年 | 24篇 |
1992年 | 13篇 |
1991年 | 17篇 |
1990年 | 16篇 |
1989年 | 16篇 |
1988年 | 17篇 |
1987年 | 17篇 |
1986年 | 23篇 |
1985年 | 30篇 |
1984年 | 19篇 |
1983年 | 19篇 |
1981年 | 12篇 |
1980年 | 20篇 |
1979年 | 26篇 |
1978年 | 16篇 |
1977年 | 22篇 |
1976年 | 16篇 |
1975年 | 16篇 |
1974年 | 24篇 |
1973年 | 16篇 |
1971年 | 13篇 |
1970年 | 10篇 |
1885年 | 17篇 |
排序方式: 共有1532条查询结果,搜索用时 15 毫秒
131.
On the Reaction of W3O with Iodine: Preparation, Crystal Structure, and Properties of WOI3 The novel tungsten oxide iodide WOI3 is obtained from the reaction of the metalrich tungsten oxide W3O (also known as ‘β-tungsten’) with iodine in a sealed glass tube placed in a temperature gradient (440–400°C). In the low-temperature region WOI3 is formed as mouse-grey intergrown needle-like crystals. WOI3 crystallizes in the tetragonal NbOCl3 structure type, space group P42/mnm, with a = 12.346(2), c = 3.765(1) Å (20°C). The crystal structure at – 130°C was determined from single-crystal diffractometer data (R = 0.023). Results of magnetic susceptibility and vibrational spectroscopic measurements are given together with the mass spectrum of WOI3 obtained on heating. 相似文献
132.
We demonstrate how the two-photon correlated emission laser (CEL) can be understood from a simple physical picture in a quasirigorous fashion. We use semiclassical arguments to derive correct expressions for the phase and amplitude diffusion in a simple way. We then illustrate how noise suppression is achieved in the two-photon CEL. 相似文献
133.
134.
Hall algebras and quantum groups 总被引:8,自引:0,他引:8
Claus Michael Ringel 《Inventiones Mathematicae》1990,101(1):583-591
135.
Despite considerable improvements in the tolerance and efficacy of novel chemotherapeutic agents, the mortality of hematological malignancies is still high due to therapy relapse, which is associated with bad prognosis. Dietary polyphenolic compounds are of growing interest as an alternative approach, especially in cancer treatment, as they have been proven to be safe and display strong antioxidant properties. Here, we provide evidence that both resveratrol and curcumin possess huge potential for application as both chemopreventive agents and anticancer drugs and might represent promising candidates for future treatment of leukemia. Both polyphenols are currently being tested in clinical trials. We describe the underlying mechanisms, but also focus on possible limitations and how they might be overcome in future clinical use--either by chemically synthesized derivatives or special formulations that improve bioavailability and pharmacokinetics. 相似文献
136.
137.
138.
139.
140.