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131.
Wojciech Samotij 《Random Structures and Algorithms》2014,44(3):269-289
Two years ago, Conlon and Gowers, and Schacht proved general theorems that allow one to transfer a large class of extremal combinatorial results from the deterministic to the probabilistic setting. Even though the two papers solve the same set of long‐standing open problems in probabilistic combinatorics, the methods used in them vary significantly and therefore yield results that are not comparable in certain aspects. In particular, the theorem of Schacht yields stronger probability estimates, whereas the one of Conlon and Gowers also implies random versions of some structural statements such as the famous stability theorem of Erd?s and Simonovits. In this paper, we bridge the gap between these two transference theorems. Building on the approach of Schacht, we prove a general theorem that allows one to transfer deterministic stability results to the probabilistic setting. We then use this theorem to derive several new results, among them a random version of the Erd?s‐Simonovits stability theorem for arbitrary graphs, extending the result of Conlon and Gowers, who proved such a statement for so‐called strictly 2‐balanced graphs. The main new idea, a refined approach to multiple exposure when considering subsets of binomial random sets, may be of independent interest.Copyright © 2012 Wiley Periodicals, Inc. Random Struct. Alg., 44, 269‐289, 2014 相似文献
132.
In the present paper a Computational Aero Acoustics approach based on Lighthill's and Curle's Acoustic Analogies was implemented in OpenFOAM 2.1.1. The novel developed OpenFOAM application solvers acousticFoam and acousticRhoFoam can be used for transient incompressible and compressible simulations respectively. The CAA approach takes High Performance Computing environment into account and realize the computation of flow and acoustic fields within the acoustical near field on one mesh only. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
133.
Henryk Krawczyk Marcin
liwiski Wojciech M. Wolf 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):o897-o899
The title compound, C11H16O2, adopts a semifolded conformation with the δ‐lactone and cyclohexane rings almost perpendicular to one another. The β‐methyl substituent occupies an axial position with respect to the cyclohexane ring. The δ‐lactone moiety adopts a slightly distorted half‐chair arrangement, while the cyclohexane ring exists in an almost ideal chair conformation. 相似文献
134.
135.
Wojciech Kiciński Mateusz Szala Marcin Nita 《Journal of Sol-Gel Science and Technology》2011,58(1):102-113
The impact of solvent composition as well as inorganic salt content and type on carbon xerogel structure was investigated.
Carbon xerogels were derived from the sol–gel polycondensation of resorcinol with furfural in a water–methanol–inorganic salt
solution. As inorganic salts, NaCl, NH4ClO4 and FeCl3 were used. In order to conduct an accurate examination of the carbon xerogel structures and textures, inorganic salts were
removed prior to carbonization. The xerogel structures can be tailored according to the water/methanol ratio and, to a lesser
extent, according to the inorganic salt content and type in the starting solution. As a result, a significant amount of salt
can be introduced to the gel network of the desired structure. The morphology and physical properties of the organic xerogels,
carbon xerogels and their composites were characterized by means of SEM, N2 sorption and XRD. It was found that samples derived from mixtures with FeCl3 manifest well developed mesoporosity and depleated microporosity in comparison to samples prepared from mixtures with NaCl
and NH4ClO4. Iron ions chemically bond to the xerogel matrix and cause its partial graphitization during the carbonization process, resulting
in enhanced mesoporosity. 相似文献
136.
Wojciech szczepinski 《基于设计的结构力学与机械力学》2013,41(1):35-53
ABSTRACT The technique of statically admissible plastic stress fields is used in the plastic design of complex connections -of steel structures. An appropriate stress field gives a safe estimate of the shape of the connection design. Complex three-dimensional stress fields are composed of elementary subfields. Thus the procedure of plastic design consists in appropriate arrangement of subfields into a complex system of stresses. 相似文献
137.
A practical molar scale syntheses of the commercially unavailable dichloro- and dibromopyromellitic acids are described in detail. 相似文献
138.
Karolina Hyz Robert Kawȩcki Elżbieta Bednarek Wojciech Bocian Jerzy Sitkowski Lech Kozerski 《Magnetic resonance in chemistry : MRC》2010,48(8):575-584
Topotecan (TPT) is in clinical use as an antitumor agent, hycamtin?. Because of this, it requires both biologically and chemically useful information to be available. TPT acts by binding to the covalent complex formed by nicked DNA and topoisomerase I. This has a poisonous effect since inserted into the single‐strand nick and TPT inhibits its religation. We used NMR to trace TPT dynamics, tautomerism and solvolysis products in various solvents and conditions. Chemical stability was assessed in methanol and DMSO as compared to water, and the regioselectivity of the N‐ and O‐methylation was studied using various alkylating agents. The reaction products of quaternization of the nitrogen atom and methylation of the oxygen atom were characterized by means of ESI MS, 1H/13C‐HMBC and ‐HSQCAD NMR. We have focused on the NMR characterization of TPT with an anticipation that its aggregation, tumbling properties and the intramolecular dipolar interactions will be a common feature for other compounds described in this article. These features can also be useful in tracing the interactions of this class of topoisomerase I (TopoI) poisons with DNA. Moreover, the results explained shed light on the recently disclosed problem of lack of stability of TPT in the heart tissue homogenate samples using the analytical assays developed for this class of compounds carried out in the presence of methanol. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
139.
140.
T. Suski E. Litwin-Staszewska P. Perlin P. Wisniewski H. Teisseyre I. Grzegory M. Bockowski S. Porowski K. Saarinen J. Nissil 《Journal of Crystal Growth》2001,230(3-4):368-371
Highly resistive GaN : Be was obtained by means of synthesis of Ga+Be with atomic nitrogen under high nitrogen pressure. Activation energy of resistivity is about 1.5 eV. This material exhibits features very different from those observed in highly resistive bulk GaN : Mg. Up to 300 K strong yellow band dominates photoluminescence spectrum in resistive GaN : Be crystals. Positron annihilation studies point to the presence of gallium vacancies, VGa. In highly resistive GaN:Mg neither yellow band with considerable intensity, nor detectable concentration of VGa was found. We also discuss the puzzling findings in highly resistive bulk GaN : Be of morphological features typical for highly conducting bulk n-GaN material. 相似文献