全文获取类型
收费全文 | 100篇 |
免费 | 0篇 |
专业分类
化学 | 47篇 |
晶体学 | 1篇 |
力学 | 1篇 |
数学 | 7篇 |
物理学 | 44篇 |
出版年
2016年 | 2篇 |
2013年 | 4篇 |
2012年 | 2篇 |
2011年 | 7篇 |
2010年 | 4篇 |
2009年 | 1篇 |
2008年 | 4篇 |
2007年 | 5篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 1篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1978年 | 1篇 |
1973年 | 2篇 |
1935年 | 2篇 |
1933年 | 3篇 |
1931年 | 1篇 |
1930年 | 1篇 |
1928年 | 1篇 |
排序方式: 共有100条查询结果,搜索用时 3 毫秒
61.
62.
63.
Logsdon LA Schardon CL Ramalingam V Kwee SK Urbach AR 《Journal of the American Chemical Society》2011,133(42):17087-17092
This paper describes the molecular recognition of phenylalanine derivatives and their peptides by the synthetic receptor cucurbit[7]uril (Q7). The 4-tert-butyl and 4-aminomethyl derivatives of phenylalanine (tBuPhe and AMPhe) were identified from a screen to have 20-30-fold higher affinity than phenylalanine for Q7. Placement of these residues at the N-terminus of model tripeptides (X-Gly-Gly), resulted in no change in affinity for tBuPhe-Gly-Gly, but a remarkable 500-fold increase in affinity for AMPhe-Gly-Gly, which bound to Q7 with an equilibrium dissociation constant (K(d)) value of 0.95 nM in neutral phosphate buffer. Structure-activity studies revealed that three functional groups work in a positively cooperative manner to achieve this extraordinary stability (1) the N-terminal ammonium group, (2) the side chain ammonium group, and (3) the peptide backbone. Addition of the aminomethyl group to Phe substantially improved the selectivity for peptide versus amino acid and for an N-terminal vs nonterminal position. Importantly, Q7 binds to N-terminal AMPhe several orders of magnitude more tightly than any of the canonical amino acid residues. The high affinity, single-site selectivity, and small modification in this system make it attractive for the development of minimal affinity tags. 相似文献
64.
H. P. Urbach 《Studies in Applied Mathematics》1990,82(2):121-180
The problem of optimum thrust generation by means of a rigid profile performing small arbitrarily periodic motions in an inviscid incompressible fluid is studied. The motions considered have to generate a prescribed mean value of thrust and must be such that the contribution to this mean thrust by the suction at the leading edge does not exceed a certain given value. Furthermore, the motions are in general subjected to a maximum type constraint on their amplitude. For this infinite dimensional, nonconvex and nonsmooth optimization problem, a generalized Lagrange multiplier rule is derived. In case the constraint on the amplitude is omitted, the optimum motions are calculated analytically; for the general case a number of properties of the solutions are derived from the Lagrange multiplier rule. 相似文献
65.
Eine einfache diastereoselektive synthese von (1sr,3sr,5sr)-2-azabicyclo [3.3.0] Octan-3-carbonsäure
(1SR,3SR,5SR)-2-Azabicyclo [3.3.0] octane-3-carboxylic acid, precursor of the angiotensin-converting-enzyme inhibitor Hoe 498, is easily prepared from 1-chloro-1-cyclopentene-2-carbaldehyde in three steps. 相似文献
66.
T. Chiarappa F. Farchioni K. Jansen I. Montvay E.E. Scholz L. Scorzato T. Sudmann C. Urbach 《The European Physical Journal C - Particles and Fields》2007,50(2):373-383
A first study of numerical Monte Carlo simulations with two quark doublets, a mass-degenerate one and a mass-split one, interpreted
as u, d, s and c quarks, is carried out in the framework of the twisted mass Wilson lattice formulation. Tuning the bare parameters
of this theory is explored on 123·24 and 163·32 lattices at lattice spacings a≃0.20 fm and a≃0.15 fm, respectively. 相似文献
67.
68.
69.
70.