全文获取类型
收费全文 | 45篇 |
免费 | 0篇 |
国内免费 | 2篇 |
专业分类
化学 | 14篇 |
数学 | 23篇 |
物理学 | 10篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2017年 | 3篇 |
2015年 | 2篇 |
2013年 | 2篇 |
2012年 | 3篇 |
2011年 | 3篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 3篇 |
2004年 | 2篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有47条查询结果,搜索用时 15 毫秒
1.
Changho Yoo Henry M. Dodge Alexandra H. Farquhar Kristen E. Gardner Alexander J. M. Miller 《Chemical science》2020,11(44):12130
A unique chain-rupturing transformation that converts an ether functionality into two hydrocarbyl units and carbon monoxide is reported, mediated by iridium(i) complexes supported by aminophenylphosphinite (NCOP) pincer ligands. The decarbonylation, which involves the cleavage of one C–C bond, one C–O bond, and two C–H bonds, along with formation of two new C–H bonds, was serendipitously discovered upon dehydrochlorination of an iridium(iii) complex containing an aza-18-crown-6 ether macrocycle. Intramolecular cleavage of macrocyclic and acyclic ethers was also found in analogous complexes featuring aza-15-crown-5 ether or bis(2-methoxyethyl)amino groups. Intermolecular decarbonylation of cyclic and linear ethers was observed when diethylaminophenylphosphinite iridium(i) dinitrogen or norbornene complexes were employed. Mechanistic studies reveal the nature of key intermediates along a pathway involving initial iridium(i)-mediated double C–H bond activation.A unique chain-rupturing transformation that converts an ether functionality into two hydrocarbyl units and carbon monoxide is reported. 相似文献
2.
For a smooth projective irreducible algebraic curve C of odd gonality, the maximal possible dimension of the variety of special linear systems W
d
r
(C) is d-3r by a result of M. Coppens et al. Furthermore it is known that if the maximum dimension of W(C) for a curve C of odd gonality is attained then C is of very special type of curves by the recent progress made by G. Martens. The purpose of this paper is to chase an extension of the result of G. Martens; if dim W(C)=d-3r-1 for a curve C of odd gonality for some dg-4 and r1, then C must be either a smooth plane sextic, a pentagonal curve of bounded genus or a smooth plane octic. 相似文献
3.
Edoardo Ballico Changho Keem Seungsuk Park 《Proceedings of the American Mathematical Society》2004,132(11):3153-3158
Let be a smooth projective algebraic curve of genus and an integer with . For all integers we prove the existence of a double covering with a smooth curve of genus and the existence of a degree morphism that does not factor through . By the Castelnuovo-Severi inequality, the result is sharp (except perhaps the bound ).
4.
It is the aim of this note to determine all smooth curves of genus g admitting a birational space model of degree g + 1 whose plane sections define a complete linear series. And we add criteria when there is a smooth such model. 相似文献
5.
Changho Keem 《manuscripta mathematica》1991,71(1):307-316
Partially supported by Korea Science & Engineering Foundation. The author is grateful to the Max-Planck-Institut für Mathematik
for the support, where a major part of this paper was written during his stay there. 相似文献
6.
J. Flasck J. Wood A.S. Edelstein J.E. Keem F.P. Missell 《Solid State Communications》1982,44(5):649-652
We have co-sputtered amorphous films of several Mo and W-based superconducting alloys. Measurements of Tc, ()Tc and the normal state resistivity near Tc were made on a number of these alloys. Our results and other data from the literature are studied to examine the correlation between Tc and the dressed density of states at the Fermi level. 相似文献
7.
The initial slopes of the acoustic phonon dispersion curves in (V0.98Cr0.02)2O3 have been measured at room temperature in several of the high symmetry directions by inelastic neutron scattering. From these data several sound velocities and four independent elastic constants have been determined. Although the Cr doped specimen is in the insulating phase and pure V2O3 is metallic, these results are in good agreement with recent data (1) obtained by ultrasonic measurements on pure V2O3. 相似文献
8.
H. Sadate-Akhavi J.T. Chen A.M. Kadin J.E. Keem S.R. Ovshinsky 《Solid State Communications》1984,50(11):975-978
We have observed that an rf current of frequency 1–5 MHz, passing through a sputtered binary superconducting film, can induce a dc voltage as large as 1 mV across the film for temperatures near the critical temperature TC. The largest induced voltage has been observed in films which are microscopically inhomogeneous, such as Mo63C37 films which exhibit columnar microstructure. We suggest that the effect may be due to an inverse ac Josephson effect in a randomly connected series array of many microscopic superconducting weak links that are expected to exist close to TC. 相似文献
9.
10.
Archiv der Mathematik - We denote by $$\mathcal {H}_{d,g,r}$$ the Hilbert scheme of smooth curves, which is the union of components whose general point corresponds to a smooth irreducible and... 相似文献