全文获取类型
收费全文 | 434篇 |
免费 | 9篇 |
专业分类
化学 | 330篇 |
晶体学 | 2篇 |
力学 | 21篇 |
数学 | 15篇 |
物理学 | 75篇 |
出版年
2020年 | 5篇 |
2019年 | 9篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2014年 | 4篇 |
2013年 | 10篇 |
2012年 | 19篇 |
2011年 | 26篇 |
2010年 | 14篇 |
2009年 | 10篇 |
2008年 | 21篇 |
2007年 | 34篇 |
2006年 | 17篇 |
2005年 | 28篇 |
2004年 | 21篇 |
2003年 | 25篇 |
2002年 | 16篇 |
2001年 | 18篇 |
2000年 | 13篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 7篇 |
1995年 | 6篇 |
1994年 | 9篇 |
1992年 | 3篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 7篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 8篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1964年 | 2篇 |
排序方式: 共有443条查询结果,搜索用时 15 毫秒
441.
Yoshimasa Tani Kazunori Sato Hiroshi Katayama-Yoshida 《Physica B: Condensed Matter》2012,407(15):3056-3058
Based on ab initio electronic structure calculations by self-interaction-corrected local-density-approximation (SIC-LDA) with the Korringa–Kohn–Rostoker coherent potential approximation (KKR-CPA), we propose a materials design for high efficiency photovoltaic solar cells (PVSCs). It is shown that (i) the concentration dependence of the mixing energy of CuIn1−xGaxSe2 shows upward convexity, thus this system favors phase separation. Due to the type II band alignment between CuInSe2 and CuGaSe2, efficient electron–hole separation is realized in decomposed phase of this system. (ii) CuIn1−xZn0.5xSn0.5xSe2 has a direct band gap and no impurity state appears in the gap. Therefore, cost reduction is possible by using Zn and Sn instead of In. (iii) n-type CuAl1−xSnxS2 and p-type Cu1−xVCuxAlS2 have negative activation energy for doped impurities and are expected to be low-resistive transparent conducting sulfides, which should be useful for CuInSe2-based PVSCs. 相似文献
442.
Yasuhiro Miwa Tomoki Nagahama Harumi Sato Atsushi Tani Kei Takeya 《Molecules (Basel, Switzerland)》2022,27(15)
Semi-clathrate hydrates are attractive heat storage materials because the equilibrium temperatures, located above 0 °C in most cases, can be changed by selecting guest cations and anions. The equilibrium temperatures are influenced by the size and hydrophilicity of guest ions, hydration number, crystal structure, and so on. This indicates that intermolecular and/or interionic interaction in the semi-clathrate hydrates may be related to the variation of the equilibrium temperatures. Therefore, intermolecular and/or interionic interaction in semi-clathrate hydrates with quaternary onium salts was directly observed using low-frequency Raman spectroscopy, a type of terahertz spectroscopy. The results show that Raman peak positions were mostly correlated with the equilibrium temperatures: in the semi-clathrate hydrates with higher equilibrium temperatures, Raman peaks around 65 cm−1 appeared at a higher wavenumber and the other Raman peaks at around 200 cm−1 appeared at a lower wavenumber. Low-frequency Raman observation is a valuable tool with which to study the equilibrium temperatures in semi-clathrate hydrates. 相似文献
443.
David Austrup Dr. Fumito Saito 《Angewandte Chemie (International ed. in English)》2023,62(51):e202315123
Sulfur monoxide (SO) is a highly reactive species that cannot be isolated in bulk. However, SO can play a pivotal role as a fundamental building block in organic synthesis. Reported herein is the design and application of a sulfinylhydrazine reagent as an easily prepared sulfur monoxide surrogate. We show facile thermal SO transfer from this reagent to dienes where a reaction using a mechanistic probe suggests the generation of singlet SO. Combined with Grignard reagents and appropriate carbon or nitrogen electrophiles, the reagent serves as an effective “SO” donor to enable the one-pot, three-component synthesis of sulfoxides and sulfinamides. 相似文献