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51.
N,N -Dimethylglycinato Complexes of Platinum(IV) The aquapentachloroplatinic acid (H3O)-[PtCl5(H2O)] · 2(18-cr-6) · 6 H2O ( 1 ) reacts with N,N-dimethylglycine (Me2glyH) to give cis-[PtCl2(N,O-Me2gly)2] · (18-cr-6) ( 6 ) and (Me2glyH2)[PtCl4(N,O-Me2gly)] ( 7 ). Complexes 6 and 7 are characterized by microanalysis, 1H-NMR and IR spectroscopy as well as by X-ray structure analysis. In both complexes the N,N-dimethylglycinato ligands are N,O-coordinated. In 6 , the amino groups are mutually trans and the carboxylato groups are cis (configuration index: OC-6–22). In the crystal, there are only weak C–H…O interactions between the N-methyl groups of the [PtCl2(N,O-Me2gly)2] complex and the oxygen atoms of the crown ether (shortest C…O contacts: 3.10(2) Å and 3.21(2) Å). In the solid state, 7 exhibits strong cation-anion interactions: The carboxyl group of the cation (Me2glyH2)+ forms a strong O–H…O bridge to the exocyclic oxygen atom of the carboxylate group of the glycinato ligand (O…O 2.61(1) Å). 相似文献
52.
Synthesis and Molecular Structure of [Li(THF)4][{(CO)4Mo}2(μ-PPh2)(μ-PPh2PPh2)]: The First Compound with an 1,3-Dimetalla-cyclopentaphosphane Ring [Mo(CO)4(NBD)] (NBD = norbornadiene) reacts with LiPPh2 and PPh2PPh2 in THF at –80 °C to give [Li(THF)4][{(CO)4Mo}2(μ-PPh2)(μ-PPh2PPh2)] ( 1 ). 1 exhibits an A2X coupling pattern in the 31P NMR spectrum. A crystal structure determination showed the presence of bridging phosphanido (PPh2) and diphosphane ligands (PPh2PPh2). The central Mo2P3 five-membered ring adopts a half-chair conformation and thus resembles an inorganic cyclopentane. 相似文献
53.
Krishna P. Singh Lokesh Baweja Olaf Wolkenhauer Qamar Rahman Shailendra K. Gupta 《Journal of computer-aided molecular design》2018,32(3):487-496
Graphene-based nanomaterials (GBNMs) are widely used in various industrial and biomedical applications. GBNMs of different compositions, size and shapes are being introduced without thorough toxicity evaluation due to the unavailability of regulatory guidelines. Computational toxicity prediction methods are used by regulatory bodies to quickly assess health hazards caused by newer materials. Due to increasing demand of GBNMs in various size and functional groups in industrial and consumer based applications, rapid and reliable computational toxicity assessment methods are urgently needed. In the present work, we investigate the impact of graphene and graphene oxide nanomaterials on the structural conformations of small hepcidin peptide and compare the materials for their structural and conformational changes. Our molecular dynamics simulation studies revealed conformational changes in hepcidin due to its interaction with GBMNs, which results in a loss of its functional properties. Our results indicate that hepcidin peptide undergo severe structural deformations when superimposed on the graphene sheet in comparison to graphene oxide sheet. These observations suggest that graphene is more toxic than a graphene oxide nanosheet of similar area. Overall, this study indicates that computational methods based on structural deformation, using molecular dynamics (MD) simulations, can be used for the early evaluation of toxicity potential of novel nanomaterials. 相似文献
54.
55.
In this paper, differences of the mechanical behaviour of several batches of 51CrV4 are shown in elongational controlled tests. The consequences of modelling the behaviour are treated with a viscoelastic-plastic model. For each batch, a new parameter set was obtained using an evolution based optimization strategy. Here, the average parameter set is shown to be inaccurate in case of using it for all batches. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
56.
Olaf Steinbach 《Numerische Mathematik》2002,90(4):775-786
Summary. In this paper we investigate a stability estimate needed in hybrid finite and boundary element methods, especially in hybrid
coupled domain decomposition methods including mortar finite elements. This stability estimate is equivalent to the stability
of a generalized projection in certain Sobolev spaces. Using piecewise linear trial spaces and appropriate piecewise constant test spaces,
the stability of the generalized projection is proved assuming some mesh conditions locally.
Received April 11, 2000 / Revised version received February 15, 2001 / Published online July 25, 2001 相似文献
57.
Olaf Hansen 《Mathematical Methods in the Applied Sciences》2002,25(12):1075-1090
In this article we study the radiosity operator along an edge between two adjacent half‐planes. First we show that the radiosity operator is invertible in a whole scale of anisotropic Sobolev spaces. In the absence of any shadows we are able to derive regularity properties of the solution, which depend only on the angle between the half‐planes, the reflectivity coefficients and the right‐hand side. This work can be considered as a supplement to the article of Rathsfeld (Mathematical Methods in the Applied Sciences 1999; 22 : 217–241). Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
58.
59.
Olaf Bröcker 《Journal of Geometry》1998,61(1-2):32-38
This note shows that a theorem of miquelian type known as (M2) holds in a certain non miquelian Laguerre plane of shear type as defined by Löwen and Pfüller[1].Dedicated to Professor H. Karzel on the occasion of his 70th birthday 相似文献
60.
Olaf Steinbach 《Numerische Mathematik》2000,84(4):679-695
Summary. In this paper we study a symmetric boundary element method based on a hybrid discretization of the Steklov–Poincaré operator
well suited for a symmetric coupling of finite and boundary elements. The representation used involves only single and double
layer potentials and does not require the discretization of the hypersingular integral operator as in the symmetric formulation.
The stability of the hybrid Galerkin discretization is based on a BBL–like stability condition for the trial spaces. Numerical
examples confirm the theoretical results.
Received December 15, 1997 / Revised version received December 21, 1998/ Published online November 17, 1999 相似文献