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The influence of surface structure of technical materials on results and statements of surface analytical methods has been investigated. Especially surface roughness as a typical property of rolled products has been observed. For this purpose samples of steel (technical surface, roughness up to 5 m) and silicon wafers (polished surface) have been analyzed by SNMS and GDOS in order to get information about changes of the surface roughness as function of the sputtering time and their influence on the statements about the depth profiles obtained. 相似文献
33.
Crh.J.W. Koch 《Thermochimica Acta》1985,95(2):395-400
Samples of synthetic goethite have been studied by combined DTA-EGA. The total CO2 content of the samples ranged between 1.0 and 2.7 %wt. The origin of the evolved CO2 is discussed and it is proposed that the samples contain CO2 as surface complexes and incorporated in the crystal structure. 相似文献
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Inhaltsübersicht. Das erstmals hergestellte B(SeCF3)3 zerfällt unter dem katalytischen Einfluß von Alkalifluoriden zu F2C=Se und BF3. In Anwesenheit von BF3 polymerisiert F2CSe bereits. bei ?;80°C. Oberhalb 150°C depolymerisiert (F2CSe)n wieder zu F2C=Se und. Durch Halogenaddition an F2C = Se gewinnt man F2XCSeX (X = Cl, Br). Das in der Reihe Cl3–nFnCSeCl noch fehlende Cl2FCSeCl wird durch Umsetzung von CSe2, ClF und Cl2 synthetisiert. FnCl3–nCSeCl (n = 1. 2) liefert mit Zinn die entsprechenden symmetrischen Diselane, mit AgCN die Selenocyanate. Durch Halogenaustausch mit BX3 (X = Cl, Br) wird umgewandelt. XC(S)Cl reagiert mit Hg(SeCF3)2 zu CF3SeC(S)X (X = F, Cl. CF3Se). Daraus werden durch Chloraddition die entsprechenden Sulfenylchloride synthetisiert. IR-NMR- und Massenspektren der neu hergestellten Substanzen werden angegeben. Preparation and Reactions of SeCF2 and its Cyclic Dimer 2,2,4,4-Tetrafluoro-1,3-diselenetane Abstract. B(SeCF3)3, prepared for the first time, decomposes under the influence of alkali metal fluorides to F2C=Se and BF3. In presence of BF3, SeCF2 polymerizes even at ?80°C. Above 150°C (F2CSe)n depolymerizes to F2C = Se and Halogen addition to F2C=Se produces F2XCSeX (X = Cl, Br). The compound Cl2FCSeCl could be synthesized by the reaction of CSe2 with ClF and Cl2. These selenenylchlorides react with tin producing the corresponding symmetric diselenides whereas with AgCN the selenocyanates are formed. can be transformed to through halogen exchange reaction with BX3 (X = Cl, Br). XC(S)Cl reacts with Hg(SeCF3)2 to give CF3SeC(S)X (X = F, Cl. CF3Se), from which the corresponding sulfenylchlorides can be synthesized by chlorine addition. I.r., n.m.r., and mass spectra of the newly prepared compounds are reported. 相似文献
35.
Daniel Koch Massimiliano Cutugno Samuel Karlson Saahil Patel Laura Wessing Paul M. Alsing 《Entropy (Basel, Switzerland)》2022,24(7)
We study an oracle operation, along with its circuit design, which combined with the Grover diffusion operator boosts the probability of finding the minimum or maximum solutions on a weighted directed graph. We focus on the geometry of sequentially connected bipartite graphs, which naturally gives rise to solution spaces describable by Gaussian distributions. We then demonstrate how an oracle that encodes these distributions can be used to solve for the optimal path via amplitude amplification. And finally, we explore the degree to which this algorithm is capable of solving cases that are generated using randomized weights, as well as a theoretical application for solving the Traveling Salesman problem. 相似文献
36.
Stephen D. Pastor David N. Rahni Nancy Khoury Stephen A. Koch 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1951-1956
The X-ray crystallographic analysis of 6,6-dimethyl-2,4,8,10-tetra-tert-octyl-dibenzo[d,f][1,3,2]dioxagermepin, 1 is reported. In the solid-state conformation of 1, the dihedral angle about the C─C sp2-sp 2 σ bond connecting the two aryl rings is 50.1°. The observed C2 symmetry in the solid-state conformation of 1 is consistent with the previously suggested solution conformation. 相似文献
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C. Baumgarten B. Braun G. Court G. Ciullo P. Ferretti G. Graw W. Haeberli M. Henoch R. Hertenberger N. Koch H. Kolster P. Lenisa A. Nass S.P. Pod'yachev D. Reggiani K. Rith M.C. Simani E. Steffens J. Stewart T. Wise 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2002,18(1):37-49
The use of storage cells has become a standard technique for internal gas targets in conjunction with high energy storage
rings. In case of spin-polarized hydrogen and deuterium gas targets the interaction of the injected atoms with the walls of
the storage cell can lead to depolarization and recombination. Thus the number of wall collisions of the atoms in the target
gas is important for modeling the processes of spin relaxation and recombination. It is shown in this article that the diffusion
process of rarefied gases in long tubes or storage cells can be described with the help of the one-dimensional diffusion equation.
Mathematical methods are presented that allow one to calculate collision age distributions (CAD) and their moments analytically.
These methods provide a better understanding of the different aspects of diffusion than Monte Carlo calculations. Additionally
it is shown that measurements of the atomic density or polarization of a gas sample taken from the center of the tube allow
one to determine the possible range of the corresponding density weighted average values along the tube. The calculations
are applied to the storage cell geometry of the HERMES internal polarized hydrogen and deuterium gas target.
Received 9 July 2001 and Received in final form 18 September 2001 相似文献