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51.
The lifetime spectroscopy of slow positron accelerated with linear accelerator and pulse punch system was first used to analyze the vacancies in the thin surface layer of silicon heavily doped with arsenic. The results demonstrated that no mono-vacancy was detected to support the arsenic-vacancy complex models for explaining the electrical deactivation mechanism of arsenic-heavily-doped silicon. 相似文献
52.
J. Ball C. D. Lac F. Lehar A. de Lesquen L. van Rossum P. Chaumette J. Derégel J. Fabre M. de Mali J. M. Fontaine F. Perrot P. Bach G. Gaillard R. Hess D. Rapin Ph. Sormani V. Ghazikhanian C. A. Whitten R. Peschina E. Rössle 《Zeitschrift fur Physik C Particles and Fields》1988,40(2):193-197
We present the measurements of the spin correlation parameterA ookk (np). A longitudinally polarized beam of free neutrons obtained from the break-up of polarized deuterons was scattered on the longitudinally polarized Saclay frozen-spin proton target. Measurements were carried out at SATURNE II, at neutron beam kinetic energies of 0.63, 0.88, 0.98 and 1.08 GeV. The data points cover the angular region from about 40° to 110° CM. The observed angular dependence ofA ookk (np) at 0.63 GeV agree with the phase shift analysis predictions except at small angles. 相似文献
53.
Molecular-orbital methods are used to provide the geometric structures and electron distributions, to improve understanding of the chemical behaviour of molecular systems. Semi-empirical algorithms, based on modified (or complete) neglect of differential overlap (MNDO and CNDO/Fischer-Kollmar) methods were applied for investigating structures and infrared spectroscopic properties of formamide, oxirene, and olefin π-complexes of nickel. By considering alternative structures (isomers), it is possible to recognize the relationships between spatial structures and their dynamics (e.g., molecular vibrations), but structure and dynamics cannot be fully separated. 相似文献
54.
The behaviour of an arc cathode in a coaxial gas stream is investigated experimentally in a pressure and current range of 15 to 120 mms Hg and 400 to 1000 A, respectively. Argon and hydrogen are used as ambient test gases. Particular phenomena occurring during the short instationary ignition period are described. Stationary operation characterized by a diffused cathode attachment covering a relatively large area is more closely studied. Measurements of the extension of the arc attachment and the distribution of the cathode temperature are made and evaluated quantitatively. Average current densities in the attachment are presented, as functions of pressure and current, by empirical expressions. Using a quasi-onedimensional approach, an interior energy balance of the cathode is set up and heat entering the cathode in the attachment region is calculated. Finally, under further simplifying assumptions, the cathode drop voltage and the fraction of current carried by ions are estimated and the so-called Richardson constant is determined assuming electron emission according to the Richardson-Schottky-equation. All data discussed depends — in general, strongly — on ambient pressure and current, and the type of gas has a substantial qualitative and quantitative influence. 相似文献
55.
56.
W. Brügel H. Bergmann H. H. G. Jellinek J. Abicht W. Koch G. W. Wolf H. Zwicky J. Abicht R. Hähnel D. Koschel 《Colloid and polymer science》1973,251(8):613-621
Ohne Zusammenfassung 相似文献
57.
CO2 laser-induced plasma CVD synthesis of diamond 总被引:1,自引:0,他引:1
V.I. Konov A.M. Prokhorov S.A. Uglov A.P. Bolshakov I.A. Leontiev F. Dausinger H. Hügel B. Angstenberger G. Sepold S. Metev 《Applied Physics A: Materials Science & Processing》1998,66(5):575-578
2 laser maintenance of a stationary optical discharge in a gas stream, exhausting over a substrate into the air (laser plasmatron).
Nano- and polycrystalline-diamond films were deposited on tungsten substrates from atmospheric-pressure Xe(Ar):H2:CH4 gas mixtures at flow rates of 2 ?/min. A 2.5-kW CO2 laser focused beam produced plasma. The deposition area was about 1 cm2 and growth rates were up to 30–50 μm/h. Peculiarities and advantages of laser plasmatrons are discussed.
Received: 15 January 1998/Accepted: 16 January 1998 相似文献
58.
59.
von Bergmann K Heinze S Bode M Vedmedenko EY Bihlmayer G Blügel S Wiesendanger R 《Physical review letters》2006,96(16):167203
We have observed a novel magnetic structure in the pseudomorphic Fe monolayer on Ir(111). Using spin-polarized scanning tunneling microscopy we find a nanometer-sized two-dimensional magnetic unit cell. A collinear magnetic structure is proposed consisting of 15 Fe atoms per unit cell with 7 magnetic moments pointing in one and 8 moments in the opposite direction. First-principles calculations verify that such an unusual magnetic state is indeed lower in energy than all solutions of the classical Heisenberg model. We demonstrate that the complex magnetic structure is induced by the strong Fe-Ir hybridization. 相似文献
60.
Moulay A. Barkatou Gary Broughton Eckhard Pflügel 《Mathematics in Computer Science》2010,4(2-3):267-288
This paper deals with the local analysis of systems of pseudo-linear equations. We define regular solutions and use this as a unifying theoretical framework for discussing the structure and existence of regular solutions of various systems of linear functional equations. We then give a generic and flexible algorithm for the computation of a basis of regular solutions. We have implemented this algorithm in the computer algebra system Maple in order to provide novel functionality for solving systems of linear differential, difference and q-difference equations given in various input formats. 相似文献