全文获取类型
收费全文 | 67篇 |
免费 | 2篇 |
专业分类
化学 | 42篇 |
晶体学 | 2篇 |
数学 | 3篇 |
物理学 | 22篇 |
出版年
2019年 | 1篇 |
2018年 | 1篇 |
2014年 | 1篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2010年 | 2篇 |
2009年 | 1篇 |
2008年 | 7篇 |
2007年 | 7篇 |
2006年 | 5篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1984年 | 2篇 |
1980年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1937年 | 1篇 |
1935年 | 1篇 |
1932年 | 1篇 |
1903年 | 1篇 |
排序方式: 共有69条查询结果,搜索用时 0 毫秒
21.
22.
23.
S. T. Bromley G. Sankar C. R. A. Catlow Th. Maschmeyer B. F. G. Johnson J. M. Thomas 《Chemical physics letters》2001,340(5-6):524-530
An ensemble of Ru12Cu4C2 bimetallic clusters derived from organometallic precursors and anchored within mesoporous silica is investigated with molecular mechanics (MM) and ab initio techniques. The computational study, guided by experiment, yields a representative cluster structure which is compared with EXAFS data. The comparison yields possible insights into the effects of cluster structure upon the thermal decomposition of the carbonyl ligands. Density functional theory (DFT) calculations suggest an unexpected structural modification of the silica-supported cluster upon removal of the attendent carbonyl ligands, in particular the displacement of the central carbido atoms. 相似文献
24.
A new form of finite silica with edge-sharing SiO2 units connected in a ring is proposed. High-level density-functional calculations for (SiO2)(N), N=4-14, show the rings to be energetically more stable than the corresponding (SiO2)(N) linear chains for N>11. The rings display frequency modes in remarkable agreement with infrared bands measured on dehydrated silica surfaces indicating their potential as models of strained extended silica systems. Silica rings, if synthesized, may also be useful precursors for new bulk-silica polymorphs with tubular or porous morphologies. 相似文献
25.
van den Berg AW Flikkema E Jansen JC Bromley ST 《The Journal of chemical physics》2005,122(20):204710
The self-diffusion coefficient of molecular hydrogen through the all-silica microporous dodecasil 3C structure is calculated by means of molecular-dynamics (MD) calculations, allowing for full framework flexibility, in order to assess the material's feasibility as a hydrogen storage medium. The hydrogen uptake rate into dodecasil 3C is compared to that previously calculated for sodalite and it is found that the latter performs significantly better. The reason for this variation in performance is found to lie in intrinsic topological differences between each framework type. This is explicitly demonstrated by means of a simplified version of transition state theory helping to succinctly rationalize the MD data. 相似文献
26.
Interaction of SiO2 with single-walled carbon nanotubes 总被引:1,自引:0,他引:1
The effects of coating of a single-walled carbon nanotube (SWNT) with a nonbonded layer of silica are investigated via model system employing fully coordinated silica clusters. The geometric and electronic structures of the SWNT@SiO(2) composite system are calculated using periodic density functional (DF) calculations for a range of confining silica coatings. We show that silica can provide a protective bound coating to a single walled nanotube, which, importantly, only weakly perturbs the underlying properties of both components. Detailed analysis of the charge redistribution and changes in electronic structure upon coating the SWNT are performed to support this conclusion. Furthermore, as allowed by our versatile model system, the energetics of rotating a silica "bearing" around a nanotube "spindle" is also calculated to indicate the possibilities for SWNT@SiO(2)-based nanomechanical devices. 相似文献
27.
We predict that tetrahedral Ce(n)O(2n) nanoparticles <2 nm in size become more stable than those experimentally observed at larger sizes with truncated octahedral morphologies, based on global optimisation and density functional calculations. 相似文献
28.
Angie?S?Mah Andrew?EH?Elia Geeta?Devgan Jason?Ptacek Mike?Schutkowski Michael?Snyder Michael?B?Yaffe Raymond?J?DeshaiesEmail author 《BMC biochemistry》2005,6(1):22
Background
The mitotic exit network (MEN) is a group of proteins that form a signaling cascade that is essential for cells to exit mitosis in Saccharomyces cerevisiae. The MEN has also been implicated in playing a role in cytokinesis. Two components of this signaling pathway are the protein kinase Dbf2 and its binding partner essential for its kinase activity, Mob1. The components of MEN that act upstream of Dbf2-Mob1 have been characterized, but physiological substrates for Dbf2-Mob1 have yet to be identified. 相似文献29.
M.C. Mermaz M. Ruscev M. Gai J.F. Ennis K.N. Gamadia J.F. Shriner N. Tsoupas S.M. Sterbenz D.A. Bromley 《Nuclear Physics A》1984,429(2):351-364
The 24Mg(12C, α)32S reaction has been studied in the region of the Coulomb barrier. Three angular distributions for the α-particle groups populating the ground and first-excited 2+ state of 32S have been measured spanning the apparent resonant structure observed at Ec.m = 14.20 MeV. Regge-pole and phase-shift analyses suggest a spin assignment of 8 for the corresponding resonance at Ex = 30.51 MeV in 36Ar. 相似文献
30.