首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   124篇
  免费   2篇
化学   36篇
晶体学   2篇
力学   4篇
数学   44篇
物理学   40篇
  2022年   1篇
  2021年   1篇
  2019年   3篇
  2016年   2篇
  2015年   1篇
  2014年   2篇
  2013年   4篇
  2012年   5篇
  2011年   10篇
  2010年   4篇
  2009年   5篇
  2008年   9篇
  2007年   2篇
  2006年   5篇
  2005年   1篇
  2004年   1篇
  2003年   2篇
  2002年   3篇
  2001年   3篇
  2000年   1篇
  1999年   3篇
  1998年   4篇
  1997年   1篇
  1996年   2篇
  1995年   2篇
  1994年   4篇
  1993年   3篇
  1992年   1篇
  1990年   6篇
  1989年   3篇
  1986年   1篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
  1981年   1篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
  1975年   4篇
  1974年   2篇
  1973年   1篇
  1972年   2篇
  1971年   1篇
  1966年   1篇
  1934年   1篇
  1917年   2篇
  1895年   2篇
  1889年   1篇
  1885年   1篇
排序方式: 共有126条查询结果,搜索用时 15 毫秒
41.
Differential cross sections for center of mass scattering angles near 90° are presented for the reactions K?°p → π+Λ°, K?°p → π+Σ° and KL°p → KS°p in the momentum interval 1.0 to 7.5 GeV/c. The energy dependences of these cross sections are found to be equally well described by the parameterization: (dσdΩ)90° ∞ s?2 or (dσdΩ)90°exp(? bp).  相似文献   
42.
43.
The degradation of mechanical properties and the moisture absorption of a carbon/epoxy composite is studied through immersion of specimens in two common types of glycol-based (corn-based and synthetic) deicing fluids at two temperatures. Test results indicate that the effects of the fluids are similar at room temperature, while at elevated temperatures, the specimens immersed in the corn-based deicing fluid show a greater drop in the tensile strength. Moreover, gravimetric analysis results show a mass gain in all specimens, with a significantly lower gain from the corn-based deicing fluid than from the synthetic one at the two temperatures selected in this study.  相似文献   
44.
A hash structure, Overflow Indexing (OVI), using an index for the overflows is presented. The index contains one entry (key, bucket number) for each overflow. Formulas for computing the expected number of entries in the index and the standard deviation are derived and the numerical results obtained using these formulae are presented in a graph. It is concluded that storing the index in the main memory when operating on the file is feasible for small to medium-sized, and sometimes even large files. The number of probes for both a successful and unsuccessful search is one. Deletion requires two probes and insertion two or three probes. Details of OVI are presented and illustrated by simulation experiments. The structure of the index is discussed and one possible structure, hashing with dynamic buckets, is presented.  相似文献   
45.
46.
47.
Human anamorsin was implicated in cytosolic iron-sulfur (Fe/S) protein biogenesis. Here, the structural and metal-binding properties of anamorsin and its interaction with Mia40, a well-known oxidoreductase involved in protein trapping in the mitochondrial intermembrane space (IMS), were characterized. We show that (1), anamorsin contains two structurally independent domains connected by an unfolded linker; (2), the C-terminal domain binds a [2Fe-2S] cluster through a previously unknown cysteine binding motif in Fe/S proteins; (3), Mia40 specifically introduces two disulfide bonds in a twin CX(2)C motif of the C-terminal domain; (4), anamorsin and Mia40 interact through an intermolecular disulfide-bonded intermediate; and (5), anamorsin is imported into mitochondria. Hence, anamorsin is the first identified Fe/S protein imported into the IMS, raising the possibility that it plays a role in cytosolic Fe/S cluster biogenesis also once trapped in the IMS.  相似文献   
48.
We study the Kobayashi pseudodistance for orbifolds, proving an orbifold version of Brody’s theorem and classifying which one-dimensional orbifolds are hyperbolic.  相似文献   
49.
At the (001) surface of the alloy Ni(50)Mn(50), a noncollinear spin density is observed in real space by spin-polarized scanning tunneling microscopy. The spin density of individual atoms also varies in both size and direction as a function of bias voltage, indicating a noncollinearity in the energy domain. The noncollinearity is driven by a surface reconstruction which breaks the otherwise high surface symmetry. First-principles electronic-structure calculations support the experimental observations and evidence the interplay of reconstruction and spin-orbit coupling.  相似文献   
50.
In an interferometric pump-probe experiment, we demonstrate the phase tuning of the spin polarization of photoelectrons emitted in a three-photon process from Cu(001). A phase shift of pi between delayed ultrafast circularly polarized light pulses can switch the spin polarization from +/-20% to -/+40%. In the delay regime of overlapping pulses, we show the dominating role of optical interference effects in determining the spin polarization. For longer delays, we detect the influence of the coherent material response, manifested in both the final state electron population as well as the final state spin polarization.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号