全文获取类型
收费全文 | 51篇 |
免费 | 4篇 |
专业分类
化学 | 35篇 |
力学 | 10篇 |
数学 | 5篇 |
物理学 | 5篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2018年 | 1篇 |
2016年 | 2篇 |
2014年 | 3篇 |
2013年 | 1篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 3篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2006年 | 4篇 |
2005年 | 1篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有55条查询结果,搜索用时 15 毫秒
1.
Berger A Djukic JP Pfeffer M de Cian A Kyritsakas-Gruber N Lacour J Vial L 《Chemical communications (Cambridge, England)》2003,(5):658-659
In the presence of large amounts of [Me4N]Cl, the reaction of ortho-chloromercurated 2-[(eta6-phenyl)tricarbonylchromium]pyridine with mu-chloro cyclopalladated aromatic compounds yields a series of new heteroleptic heterodinuclear cis-(C--N)2Pd(II) complexes, which are valuable precursors of planar chiral cyclopalladated (eta6-arene)Cr(CO)3 complexes. 相似文献
2.
3.
Dr. Franck Ulm Dr. Yann Cornaton Dr. Jean-Pierre Djukic Prof. Michael J. Chetcuti Prof. Vincent Ritleng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(41):8916-8925
The pentamethylcyclopentadienyl N-heterocyclic carbene nickel complex [Ni(η5-C5Me5)Cl(IMes)] (IMes=1,3-dimesitylimidazol-2-ylidene) efficiently catalyses the anti-Markovnikov hydroboration of alkenes with catecholborane in the presence of a catalytic amount of potassium tert-butoxide, and joins the very exclusive club of nickel catalysts for this important transformation. Interestingly, the regioselectivity can be reversed in some cases by using pinacolborane instead of catecholborane. Mechanistic investigations involving control experiments, 1H and 11B NMR spectroscopy, cyclic voltammetry, piezometric measurements and DFT calculations suggest an initial reduction of the NiII precursor to a NiI active species with the concomitant release of H2. The crucial role of the alkoxo-catecholato-borohydride species resulting from the reaction of potassium tert-butoxide with catecholborane in the formation of an intermediate nickel-hydride species that would then be reduced to the NiI active species, is highlighted. 相似文献
4.
de Cian A Djukic JP Fischer J Pfeffer M Dötz KH 《Chemical communications (Cambridge, England)》2002,(6):638-639
The reactions of bis-cyclomanganated 2,3-diphenylquinoxaline with diazodiphenylmethane and 9-diazofluorene allowed the formation of a new oligomeric and dinuclear manganospiralene and the ready preparation of a pentacyclic helix comprising two (eta 5-fluorenyl)Mn(CO)3 fragments, whose helicity can be locked upon one-dimensional linear coordination to silver cation. 相似文献
5.
Djordje S. Djukic 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1974,25(4):532-535
Summary Using Noether's theorem and the generalized Killing equations [1], new first integrals of the differential equation of motion for a class of non-conservative mechanical systems with one degree of freedom, a special case of which is a simple pendulum of variable length, are obtained. These integrals are identified as Lyapunov's functions for non-autonomous systems. The stability conditions are established.
Zusammenfassung Mit Hilfe des Noetherschen Satzes und den verallgemeinerten Killingschen Gleichungen werden neue erste Integrale der Bewegungsdifferentialgleichungen für eine Klasse von nichtkonservativen mechanischen Systemen mit einem Freiheitsgrad, die das Pendel mit veränderlicher Länge als Sonderfall enthält, hergeleitet. Diese Integrale stellen Ljapunovsche Funktionen dar, mit denen sich die Stabilitätsbedingungen ergeben.相似文献
6.
Jean-Pierre Djukic Michel Pfeffer Nathalie Gruber-Kyritsakas André de Cian 《Journal of organometallic chemistry》2011,696(20):3268-3273
A Mn(I) tricarbonyl complex of a 1,3-diferrocenyl-1-oxopentadienyl ligand was synthesised adventitiously by what seems to be an in-situ aldol-like condensation of two acetylferrocene units promoted by benzyl-Mn(CO)5. X-ray structural analysis of this unexpected product confirms the η5 coordination of the 1,3-diferrocenyl-1-oxopentadienyl ligand to the Mn(CO)3 moiety. The nature of the metal-ligand bonding relationship was studied by theoretical calculations; it outlines the charge unbalance (polarisation) at the oxopentadienyl moiety as well as the lack of ketone character of the latter Mn-bound ligand. 相似文献
7.
In this paper the procedure for the dynamic analysis of body separation is introduced. Based on the general laws of classical
dynamics, the method for obtaining the velocity and the angular velocity of the remainder body during separation is developed.
Due to the discontinual mass variation, the jump-like change of the velocity and the angular velocity of the body is evident.
Various types of motion of the separated body are considered. Depending on the type of motion of the separated body the dynamic
properties of the remainder body are obtained. As a special case the in-plane motion of the body before and after separation
is considered. The theoretical considerations are applied for the separation analysis of a rotor (a shaft-disc system). The
transient motion of the body after separation is investigated. To prove the correctness of the procedure suggested in the
paper, the case when the mass and the moment of inertia of the separated body are infinitesimal is analyzed. The obtained
differential equations are the same as those previously obtained. 相似文献
8.
Error bounds for a wide class of nonlinear one-dimensional boundary value problems are derived from a new extremum variational principle. A new least-squares approximate technique, based on a weighted mean square residual, is established. Also, the value of the weighted mean square residual and value of the classical mean square residual are used for error estimate. The results are illustrated by four examples. 相似文献
9.
This critical review provides a systematic classification of the synthetic routes to planar-chiral five-membered metallacycles into several routes, namely C-H bond activation, oxidative addition, transmetallation and optical resolution. As a characteristic of these bulk compounds is that they are synthesized as binary mixtures of enantiomers in proportions varying from the racemate to enantiopure, a review of absolute-configuration determination of the title planar-chiral scalemates is presented. This review is of interest to organic and organometallic synthetic chemists involved in asymmetric synthesis (97 references). 相似文献
10.
Djukic JP Iali W Pfeffer M Le Goff XF 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(19):6063-6078
Facial selectivity during the π-coordination of pseudo-tetrahedral iridacycles by neutral (Cr(CO)(3)), monocationic (Cp*Ru(+)), and biscationic (Cp*Ir(2+)) metal centers was directly influenced by the coulombic imbalance in the coordination sphere of the chelated Ir center. We also showed by using theoretical calculations that the feasibility of the related metallacycles that displayed metallocenic planar chirality was dependent to the presence of an electron-donating group, such as NMe(2), which contributed to the overall stability of the complexes. When the π-bonded moiety was the strongly electron-withdrawing Cp*Ir(2+) group, the electron donation from NMe(2) resulted in major conformational changes, with a barrier to rotation of about 17?kcal mol(-1) for this group that became spectroscopically diastereotopic (high-field (1)H?NMR spectroscopy). This peculiar property is proposed as a means to introduce a new type of constitutional chirality at the nitrogen center: planar chirality at tertiary aromatic amines. 相似文献