全文获取类型
收费全文 | 175篇 |
免费 | 6篇 |
专业分类
化学 | 147篇 |
数学 | 1篇 |
物理学 | 33篇 |
出版年
2021年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 2篇 |
2012年 | 12篇 |
2011年 | 21篇 |
2010年 | 9篇 |
2009年 | 3篇 |
2008年 | 12篇 |
2007年 | 11篇 |
2006年 | 10篇 |
2005年 | 15篇 |
2004年 | 9篇 |
2003年 | 9篇 |
2002年 | 12篇 |
2001年 | 3篇 |
2000年 | 7篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1989年 | 3篇 |
1986年 | 1篇 |
1982年 | 2篇 |
1979年 | 1篇 |
1975年 | 2篇 |
1974年 | 3篇 |
排序方式: 共有181条查询结果,搜索用时 15 毫秒
101.
102.
Xueyang Li Hongyu Yu Feng Lou Junsheng Feng Myung-Hwan Whangbo Hongjun Xiang 《Molecules (Basel, Switzerland)》2021,26(4)
The effective spin Hamiltonian method has drawn considerable attention for its power to explain and predict magnetic properties in various intriguing materials. In this review, we summarize different types of interactions between spins (hereafter, spin interactions, for short) that may be used in effective spin Hamiltonians as well as the various methods of computing the interaction parameters. A detailed discussion about the merits and possible pitfalls of each technique of computing interaction parameters is provided. 相似文献
103.
Electronic structure calculations were performed to examine the origin of a band gap present in most 18-electron half-Heusler compounds and its absence in NaTl. In these compounds of diamond-like structures, the presence or absence of a band gap is controlled by the sigma antibonding between the valence s orbitals, and the bonding characteristics of the late-main-group elements depend on the extent of their ns/np hybridization. Implications of these observations on the formal oxidation state and the covalent bonding of the transition-metal atoms in 18-electron half-Heusler and related compounds were discussed. 相似文献
104.
Corrigendum: Structure and Composition of the 200 K‐Superconducting Phase of H2S at Ultrahigh Pressure: The Perovskite (SH−)(H3S+)
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
105.
Yuemei Zhang Erjun Kan Hongjun Xiang Antoine Villesuzanne Myung‐Hwan Whangbo 《ChemInform》2011,42(16):no-no
106.
Jamie L. Manson Tom Lancaster Stephen J. Blundell Yiming Qiu John Singleton Pinaki Sengupta Francis L. Pratt Jinhee Kang Changhoon Lee Myung-Hwan Whangbo 《Polyhedron》2010
The magnetic properties of α-Cu(dca)2(pyz) were examined by magnetic susceptibility, magnetization, inelastic neutron scattering (INS), muon-spin relaxation (μSR) measurements and by first-principles density functional theoretical (DFT) calculations and quantum Monte Carlo (QMC) simulations. The χ versus T curve shows a broad maximum at 3.5 K, and the data between 2 and 300 K is well described by an S = 1/2 Heisenberg uniform chain model with g = 2.152(1) and J/kB = −5.4(1) K. μSR measurements, conducted down to 0.02 K and as a function of longitudinal magnetic field, show no oscillations in the muon asymmetry function A(t). This evidence, together with the lack of spin wave formation as gleaned from INS data, suggests that no long-range magnetic order takes place in α-Cu(dca)2(pyz) down to the lowest measured temperatures. Electronic structure calculations further show that the spin exchange is significant only along the Cu–pyz–Cu chains, such that α-Cu(dca)2(pyz) can be described by a Heisenberg antiferromagnetic chain model. Further support for this comes from the M versus B curve, which is strongly concave owing to the reduced spin dimensionality. α-Cu(dca)2(pyz) is a molecular analogue of KCuF3 owing to dx2-y2 orbital ordering where nearest-neighbor magnetic orbital planes of the Cu2+ sites are orthogonal in the planes perpendicular to the Cu–pyz–Cu chains. 相似文献
107.
Zhao Q Darriet J Whangbo MH Ye L Stackhouse C zur Loye HC 《Journal of the American Chemical Society》2011,133(51):20981-20994
In this paper we report the crystal growth, structure determination, and magnetic properties of the 2H-perovskite related oxides, Sr(5)Co(4)O(12) and Sr(6)Co(5)O(15), as well as the charge disproportionation and associated phase transition of Sr(5)Co(4)O(12). Sr(5)Co(4)O(12) and Sr(6)Co(5)O(15) are the (m = 2, n = 3) and (m = 1, n = 1) members of the A(3m+3n)A'(n)B(3m+n)O(9m+6n) family, respectively. Sr(6)Co(5)O(15) crystallizes in the space group R32 with lattice parameters of a = 9.5020(10) ? and c = 12.379(8) ?. The structure solution shows that Sr(6)Co(5)O(15) is isostructural with Sr(6)Rh(5)O(15). Magnetic measurements do not indicate any long-range magnetic order, although the Weiss temperature of -248 K indicates the presence of dominant antiferromagnetic interactions. Sr(5)Co(4)O(12) crystallizes in the space group P-3c1 with lattice parameters of a = 9.4705(10) ? and c = 20.063(5) ? at room temperature. The single crystal structure solution revealed that the cobalt ions in the trigonal prismatic sites of Sr(5)Co(4)O(12) undergo a structural transition at ~170 K, where the cobalt atoms are in the center of the trigonal prisms below this temperature and move partially toward the faces above this temperature. This structure transition is accompanied by a change in the magnetic moment of the oxide and can be related to a valence disproportionation of the cobalt ions and a concomitant Jahn-Teller distortion. In addition, specific heat, Seebeck coefficient, electric conductivity, and magnetic measurements as well as bond valence sum calculations were carried out for Sr(5)Co(4)O(12). Sr(5)Co(4)O(12) exhibits strong magnetic anisotropy but no long-range magnetic order. 相似文献
108.
109.
110.
Two‐Orbital Three‐Electron Stabilizing Interaction for Direct Co2+As3+ Bonds involving Square‐Planar CoO4 in BaCoAs2O5
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Rénald David Houria Kabbour Alain Pautrat Nadia Touati Myung‐Hwan Whangbo Olivier Mentré 《Angewandte Chemie (International ed. in English)》2014,53(12):3111-3114
The quest for new oxides with cations containing active lone‐pair electrons (E) covers a broad field of targeted specificities owing to asymmetric electronic distribution and their particular band structure. Herein, we show that the novel compound BaCoAs2O5, with lone‐pair As3+ ions, is built from rare square‐planar Co2+O4 involved in direct bonding between As3+E and Co2+ dz2 orbitals (Co? As=2.51 Å). By means of DFT and Hückel calculations, we show that this σ‐type overlapping is stabilized by a two‐orbital three‐electron interaction allowed by the high‐spin character of the Co2+ ions. The negligible experimental spin‐orbit coupling is expected from the resulting molecular orbital scheme in O3AsE–CoO4 clusters. 相似文献