全文获取类型
收费全文 | 340篇 |
免费 | 19篇 |
专业分类
化学 | 232篇 |
晶体学 | 1篇 |
力学 | 1篇 |
数学 | 15篇 |
物理学 | 110篇 |
出版年
2023年 | 7篇 |
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 8篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2016年 | 14篇 |
2015年 | 15篇 |
2014年 | 10篇 |
2013年 | 29篇 |
2012年 | 22篇 |
2011年 | 18篇 |
2010年 | 14篇 |
2008年 | 11篇 |
2007年 | 16篇 |
2006年 | 8篇 |
2005年 | 13篇 |
2004年 | 7篇 |
2003年 | 9篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 7篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 9篇 |
1995年 | 12篇 |
1994年 | 12篇 |
1993年 | 11篇 |
1992年 | 11篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1981年 | 2篇 |
1978年 | 4篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1972年 | 5篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1938年 | 2篇 |
1916年 | 2篇 |
1889年 | 1篇 |
1883年 | 2篇 |
1871年 | 1篇 |
1869年 | 1篇 |
排序方式: 共有359条查询结果,搜索用时 15 毫秒
71.
72.
From an Icosahedron to a Plane: Flattening Dodecaiodo‐dodecaborate by Successive Stripping of Iodine
Dr. Pau Farràs Dr. Nina Vankova Lei Liu Zeonjuk Jonas Warneke Dr. Thomas Dülcks Prof. Dr. Thomas Heine Prof. Dr. Clara Viñas Prof. Dr. Francesc Teixidor Prof. Dr. Detlef Gabel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(41):13208-13212
It has been shown by electrospray ionization–ion‐trap mass spectrometry that B12I122? converts to an intact B12 cluster as a result of successive stripping of single iodine radicals or ions. Herein, the structure and stability of all intermediate B12In? species (n=11 to 1) determined by means of first‐principles calculations are reported. The initial predominant loss of an iodine radical occurs most probably via the triplet state of B12I122?, and the reaction path for loss of an iodide ion from the singlet state crosses that from the triplet state. Experimentally, the boron clusters resulting from B12I122? through loss of either iodide or iodine occur at the same excitation energy in the ion trap. It is shown that the icosahedral B12 unit commonly observed in dodecaborate compounds is destabilized while losing iodine. The boron framework opens to nonicosahedral structures with five to seven iodine atoms left. The temperature of the ions has a considerable influence on the relative stability near the opening of the clusters. The most stable structures with five to seven iodine atoms are neither planar nor icosahedral. 相似文献
73.
A systematic theoretic study on clusters containing edge-bridged octahedral metal units [Nb6Cl12] n (n?=?2, 3, or 4) and a large variety of ligands has been performed. The benchmark results on the [Nb6Cl 12 i ] n+ and [Nb6Cl 12 i Cl 6 a ] n (n?=?2, 3 or 4) cluster units demonstrated the reliability of GGA PBE functional in combination with ZORA TZP basis set for the Nb-containing coordination compounds. The geometrical, electronic, and vibrational properties of large variety of substituted Nb6Cl 12 i Y 6 a clusters have been provided. One- and two-dimensional structures with a [Nb6Cl 12 i (Bipyr) x Cl 6?x a ] (x?=?2 and 4) building blocks have been proposed as good and stable candidates for new coordination polydimensional materials. 相似文献
74.
75.
3 , β-BaB2O4, and LiB3O5 yielded a maximum output power of 550 mW at 473 nm with β-BaB2O4 as the nonlinear crystal.
Received: 15 September 1997 相似文献
76.
77.
78.
79.
Janet Heine Barnett 《Periodica Mathematica Hungarica》1995,30(3):171-176
It is consistent that 1(1,(:n))2 holds in any random extension for n finite and countable. 相似文献
80.