全文获取类型
收费全文 | 179篇 |
免费 | 5篇 |
国内免费 | 9篇 |
专业分类
化学 | 90篇 |
晶体学 | 5篇 |
力学 | 8篇 |
数学 | 54篇 |
物理学 | 36篇 |
出版年
2023年 | 1篇 |
2022年 | 6篇 |
2021年 | 5篇 |
2020年 | 8篇 |
2019年 | 12篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 1篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 6篇 |
2011年 | 14篇 |
2010年 | 5篇 |
2009年 | 7篇 |
2008年 | 9篇 |
2007年 | 9篇 |
2006年 | 14篇 |
2005年 | 13篇 |
2004年 | 12篇 |
2003年 | 3篇 |
2002年 | 6篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 8篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1983年 | 1篇 |
排序方式: 共有193条查询结果,搜索用时 0 毫秒
191.
Bogdan M. Leu Graeme R.A. Wyllie W.Robert Scheidt E.Ercan Alp J.Timothy Sage 《Journal of Physics and Chemistry of Solids》2005,66(12):2250-2256
High-resolution X-ray measurements near a nuclear resonance reveal the complete vibrational spectrum of the probe nucleus. Because of this, nuclear resonance vibrational spectroscopy (NRVS) is a uniquely quantitative probe of the vibrational dynamics of reactive iron sites in proteins and other complex molecules. Our measurements of vibrational fundamentals have revealed both frequencies and amplitudes of 57Fe vibrations in proteins and model compounds. Information on the direction of Fe motion has also been obtained from measurements on oriented single crystals, and provides an essential test of normal mode predictions. Here, we report the observation of weaker two-quantum vibrational excitations (overtones and combinations) for compounds that mimic the active site of heme proteins. The predicted intensities depend strongly on the direction of Fe motion. We compare the observed features with predictions based on the observed fundamentals, using information on the direction of Fe motion obtained either from DFT predictions or from single crystal measurements. Two-quantum excitations may become a useful tool to identify the directions of the Fe oscillations when single crystals are not available. 相似文献
192.
We prove that a finite solvable group G admitting a Frobenius group FH of automorphisms of coprime order with kernel F and complement H such that [G, F] = G and C C G (F)(h) = 1 for all nonidentity elements h ∈ H, is of nilpotent length equal to the nilpotent length of the subgroup of fixed points of H. 相似文献
193.
Soner Buytoz Fethi Dagdelen Serkan Islak Mediha Kok Durmus Kir Ercan Ercan 《Journal of Thermal Analysis and Calorimetry》2014,117(3):1277-1283
Copper matrix with an individual addition of TiC particles was prepared by means of powder metallurgy and hot pressing process, and the effect of TiC addition on microstructure, thermal properties, and electrical conductivity of Cu–TiC composites was investigated. The TiC quantity was changed as 1, 3, 5, 10, and 15 Cu (in mass%), and Cu–TiC powder mixtures were hot-pressed for 4 min at 700 °C under an applied pressure of 50 MPa. Microstructure studies revealed that TiC particles were distributed uniformly in the Cu matrix. Thermal Analysis result showed that there were two exothermic peaks and with rising TiC rate, oxidation amount of Cu composite decreased. With the increasing addition of TiC, hardness of composites changed between 58.6 HV0.1 and 87.8 HV0.1. The highest electrical conductivity for Cu–TiC composites was obtained in the Cu-1 mass% TiC composite, with approximately 81.2 % IACS. 相似文献