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101.
Volodymyr V. Lyubashenko 《Communications in Mathematical Physics》1995,172(3):467-516
An example of a finite dimensional factorizable ribbon Hopf -algebra is given by a quotientH=u
q
(g) of the quantized universal enveloping algebraU
q
(g) at a root of unityq of odd degree. The mapping class groupM
g,1
of a surface of genusg with one hole projectively acts by automorphisms in theH-moduleH
*g
, ifH
* is endowed with the coadjointH-module structure. There exists a projective representation of the mapping class groupM
g,n
of a surface of genusg withn holes labeled by finite dimensionalH-modulesX
1, ...,X
n
in the vector space Hom
H
(X
1 ... X
n
,H
*g
). An invariant of closed oriented 3-manifolds is constructed. Modifications of these constructions for a class of ribbon Hopf algebras satisfying weaker conditions than factorizability (including most ofu
q
(g) at roots of unityq of even degree) are described.This work was supported in part by the EPSRC research grant GR/G 42976. 相似文献
102.
103.
Dmytro S. Nesterov Volodymyr N. Kokozay Brian W. Skelton 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(6):m246-m248
The crystal structure of the title compound, triacetato‐1κO;3κ4O,O′‐(2,2′‐iminodiethanol)‐1κ3O,N,O′‐bis(μ‐2,2′‐iminodiethanolato)‐1κ2O:2κ6O,N,O′:3κ2O′‐cobalt(III)copper(II)zinc(II), [CoCuZn(C4H9NO2)2(C2H3O2)3(C4H11NO2)], shows a molecule with a triangular three‐metal core. The metal sites were refined with full occupancies, but the possibility that the Zn and Cu positions are actually mixed Cu/Zn sites cannot be excluded. The intermetallic Cu⋯Co and Co⋯Zn distances are 2.924 (3) and 2.906 (3) Å, respectively. The neutral molecules are held together by N—H⋯O hydrogen bonds involving amine groups from the 2,2′‐iminodiethanol ligands and acetate groups to build two‐dimensional layers. 相似文献
104.
Taras I. Chaban Volodymyr V. Ogurtsov Ihor G. Chaban Olena V. Klenina Josef D. Komarytsia 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):1611-1620
Abstract 5,7-Dimethyl-3H-thiazolo[4,5-b]pyridine-2-one was obtained under the reaction of 4-iminothiazolidin-2-one with acetylacetone. Further structural modifications include the introduction of diversity at the N3 and C6 positions. The antioxidant activity of the synthesized compounds was evaluated in vitro by the method of scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. [Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the following free supplemental files: Additional figures] 相似文献
105.
106.
107.
108.
Sergey Holovach Dr. Kostiantyn P. Melnykov Artem Skreminskiy Maksym Herasymchuk Olha Tavlui Danylo Aloshyn Dr. Petro Borysko Prof. Dr. Alexander B. Rozhenko Prof. Dr. Sergey V. Ryabukhin Prof. Dr. Dmitriy M. Volochnyuk Prof. Dr. Oleksandr O. Grygorenko 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(19):e202200331
Physico-chemical properties important to drug discovery (pKa, LogP, and aqueous solubility), as well as metabolic stability, were studied for a series of functionalized gem-difluorinated cycloalkanes and compared to those of non-fluorinated and acyclic counterparts to evaluate the impact of the fluorination. It was found that the influence of the CF2 moiety on the acidity/basicity of the corresponding carboxylic acids and amines was defined by inductive the effect of the fluorine atoms and was nearly the same for acyclic and cyclic aliphatic compounds. Lipophilicity and aqueous solubility followed more complex trends and were affected by the position of the fluorine atoms, ring size, and even the nature of the functional group present; also, significant differences were found for the acyclic and cyclic series. Also, gem-difluorination either did not affect or slightly improved the metabolic stability of the corresponding model derivatives. The presented results can be used as a guide for rational drug design employing fluorine and establish the first chapter in a catalog of the key in vitro properties of fluorinated cycloalkanes. 相似文献
109.
Dr. Piotr A. Guńka Dr. Anna Olejniczak Dr. Samuele Fanetti Prof. Dr. Roberto Bini Dr. Ines E. Collings Dr. Volodymyr Svitlyk Dr. Kamil F. Dziubek 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(3):1094-1102
High-pressure behavior of hexamethylenetetramine (urotropine) was studied in situ using angle-dispersive single-crystal synchrotron X-ray diffraction (XRD) and Fourier-transform infrared absorption (FTIR) spectroscopy. Experiments were conducted in various pressure-transmitting media to study the effect of deviatoric stress on phase transformations. Up to 4 GPa significant damping of molecular librations and atomic thermal motion was observed. A first-order phase transition to a tetragonal structure was observed with an onset at approximately 12.5 GPa and characterized by sluggish kinetics and considerable hysteresis upon decompression. However, it occurs only in non-hydrostatic conditions, induced by deviatoric or uniaxial stress in the sample. This behavior finds analogies in similar cubic crystals built of highly symmetric cage-like molecules and may be considered a common feature of such systems. DFT computations were performed to model urotropine equation of state and pressure dependence of vibrational modes. The first successful Hirshfeld atom refinements carried out for high-pressure diffraction data are reported. The refinements yielded more realistic C−H bond lengths than the independent atom model even though the high-pressure diffraction data are incomplete. 相似文献
110.
Jonas Köhling Dr. Volodymyr Kozel Dr. Vladislav Jovanov Dr. Romana Pajkert Dr. Sergey N. Tverdomed Oleg Gridenco Malte Fugel Prof. Dr. Simon Grabowsky Prof. Dr. Gerd-Volker Röschenthaler Prof. Dr. Veit Wagner 《Chemphyschem》2019,20(5):665-671
A blue-light emitting material based on a boron complex containing heteroaromatic phosphonate ligand is synthesized and characterized. The Phospho-Fries rearrangement is used in the synthesis route of the ligand as a convenient method of introducing phosphonate groups into phenols. Structural, thermal and photophysical properties of the resulting oxazaborinin phosphonate compound have been characterized. DFT geometry optimizations were studied as well as the spatial position and symmetry of the HOMO and LUMO. Good thermal stability up to 250 °C enables vacuum deposition methods next to solution processing. Combining the work function with the optical band gap from UV-Vis measurements shows that band alignment is possible with standard contact materials. Photoluminescence reveals an emission peak at 428 nm, which is suitable for a blue light-emitter. 相似文献