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71.
Adam NE Alexander JP Berkelman K Cassel DG Crede V Duboscq JE Ecklund KM Ehrlich R Fields L Galik RS Gibbons L Gittelman B Gray R Gray SW Hartill DL Heltsley BK Hertz D Jones CD Kandaswamy J Kreinick DL Kuznetsov VE Mahlke-Krüger H Meyer TO Onyisi PU Patterson JR Peterson D Phillips EA Pivarski J Riley D Ryd A Sadoff AJ Schwarthoff H Shi X Shepherd MR Stroiney S Sun WM Urner D Wilksen T Weaver KM Weinberger M Athar SB Avery P Breva-Newell L Patel R Potlia V Stoeck H Yelton J Rubin P Cawlfield C 《Physical review letters》2006,96(8):082004
We observe signals for the decays psi(3770) --> XJ/psi from data acquired with the CLEO detector operating at the CESR e+ e- collider with square root of s = 3773 MeV. We measure the following branching fractions Beta(psi(3770) --> XJ/psi and significances: (189 +/- 20 +/- 20) x 10(-5) (11.6sigma) for X = pi+ pi-, (80 +/- 25 +/- 16) x 10(-5) (3.4sigma) for X = pi0 pi0, and (87 +/- 33 +/- 22) x 10(-5) (3.5sigma) for X = eta, where the errors are statistical and systematic, respectively. The radiative return process e+ e- --> gamma psi(2S) populates the same event sample and is used to measure Gamma ee[psi(2S)] = (2.54 +/- 0.03 +/- 0.11) keV. 相似文献
72.
Nelsen SF Weaver MN Luo Y Pladziewicz JR Ausman LK Jentzsch TL O'Konek JJ 《The journal of physical chemistry. A》2006,110(41):11665-11676
Sixty-five electron-transfer reactions including 27 new 0, +1 couples have been added to our data set of cross-reactions between 0 and +1 couples, bringing it to 206 reactions involving 72 couples that have been studied by stopped-flow kinetics in acetonitrile containing supporting electrolyte at 25 degrees C, formal potentials determined by cyclic voltammetry, and analyzed using Marcus cross-rate theory. Perhaps surprisingly, a least-squares analysis demonstrates that intrinsic rate constants exist that predict the cross-rate constants to within a factor of 2 of the observed ones for 93% of the reactions studied, and only three of the reactions have a cross-rate constant that lies outside of the factor of 3, that corresponds to a factor of 10 uncertainty in the rate constant for an unknown couple. Many triarylamines, which have very high intrinsic reactivity, are included among the newly studied couples. The enthalpy contribution to the Marcus reorganization energy, lambda'v, has been calculated for 46 of the couples studied, at the (U)B3LYP/6-31+G (or for the larger and lower barrier compounds, at the less time-consuming (U)B3LYP/6-31G) level. In combination with a modified Levich and Dogodnadze treatment that assumes that the rate constant is proportional to (KeHab2/lambda1/2) exp[-DeltaG/RT], this allows estimation of the electronic coupling (Hab) at the transition state for intermolecular electron transfer, (more properly H'ab, the product of the square root of the encounter complex formation constant times Hab) for these couples. Although the principal factor affecting intermolecular electron-transfer rate constants is clearly lambda, H'ab effects are easily detectable, and the dynamic range in our estimates of them is over a factor of 600. 相似文献
73.
Lockard JV Valverde G Neuhauser D Zink JI Luo Y Weaver MN Nelsen SF 《The journal of physical chemistry. A》2006,110(1):57-66
Excited state mixed valence (ESMV) occurs in molecules in which the ground state has a symmetrical charge distribution but the excited state possesses two or more interchangeably equivalent sites that have different formal oxidation states. Although mixed valence excited states are relatively common in both organic and inorganic molecules, their properties have only recently been explored, primarily because their spectroscopic features are usually overlapped or obscured by other transitions in the molecule. The mixed valence excited state absorption bands of 2,3-di-p-anisyl-2,3-diazabicyclo[2.2.2]octane radical cation are well-separated from others in the absorption spectrum and are particularly well-suited for detailed analysis using the ESMV model. Excited state coupling splits the absorption band into two components. The lower energy component is broader and more intense than the higher energy component. The absorption bandwidths are caused by progressions in totally symmetric modes, and the difference in bandwidths is caused by the coordinate dependence of the excited state coupling. The Raman intensities obtained in resonance with the high and low energy components differ significantly from those expected based on the oscillator strengths of the bands. This unexpected observation is a result of the excited state coupling and is explained by both the averaging of the transition dipole moment orientation over all angles for the two types of spectroscopies and the coordinate-dependent coupling. The absorption spectrum is fit using a coupled two-state model in which both symmetric and asymmetric coordinates are included. The physical meaning of the observed resonance Raman intensity trends is discussed along with the origin of the coordinate-dependent coupling. The well-separated mixed valence excited state spectroscopic components enable detailed electronic and resonance Raman data to be obtained from which the model can be more fully developed and tested. 相似文献
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76.
Anthony Weaver 《Geometriae Dedicata》2013,163(1):141-158
One-vertex maps (a type of dessin d’enfant) give a uniform characterization of certain well-known algebraic curves, including those of Klein, Wiman, Accola–Maclachlan and Kulkarni. The characterization depends on a new classification of one-vertex (dually, one-face or unicellular) maps according to the size of the group of map automorphisms. We use an equivalence relation appropriate for studying the faithful action of the absolute Galois group on dessins, although we do not pursue that line of inquiry here. 相似文献
77.
This paper presents a model of the strategic behavior of firms operating in a spatial supply chain network. The manufacturing and retailing firms engage in an oligopolistic, noncooperative game by sharing customer demand such that a firm’s decisions impact the product prices, which in turn result in changes in all other firms’ decisions. Each firm’s payoff is to maximize its own profit and we show that, in response to such changes in prices and to exogenous environmental taxes, the manufacturing firms may strategically alter a variety of choices such as ’make-buy’ decisions with respect to intermediate inputs, spatial distribution of production, product shipment patterns and inventory management, environmental tax payment vs recycling decisions, and timing of all such choices to sustainably manage the profit and the environmental regulations. An important implication is that effects of a tax depends on the oligopolistic game structure. With respect to methods, we show that this dynamic game can be represented as a set of differential variational inequalities (DVIs) that motivate a computationally efficient nonlinear complementarity (NCP) approach that enables the full exploitation of above-mentioned salient features. We also provide a numerical example that confirms the utility of our proposed framework and shows substantial strategic reaction can be expected to a tax on pollution stocks. 相似文献
78.
C Vasilakis C Pagel S Gallivan D Richards A Weaver M Utley 《The Journal of the Operational Research Society》2013,64(7):1049-1059
We describe a modelling toolkit that was developed with the aim of assisting those responsible for introducing stepped care systems to local mental health services in the UK. The toolkit was pre-populated with real patient flow data collected from four sites that piloted the stepped care system design. Two analytical models were developed and coded as part of the toolkit to provide insights concerning workload, patient throughput, and changes in waiting times and waiting list size. An interface was built to allow users to specify their own stepped care system and input their own estimates or data of service demands and capacities at different steps. Despite the challenges and limitations, the use of modelling to inform the design of new service configurations is an important step in the right direction and we would recommend this as a reasonable way forward. 相似文献
79.
80.
J. Matzerath Niels Jörgen Traberg Arthur Wilhelmi G. Wempe Gasmotorenfabrik Deutz F. D. Harger Greiner Friedrichs Hammermann E. J. Goegg H. C. Deming E. Mauguin Otto Johannsen H. N. Gilbert G. A. Burrell E. R. Weaver J. D. Edwards R. Henr Forrières A. H. Elliot G. H. Oberfell G. Frerichs E. Mannheim F. W. Richardson A. Jaffée H. Kaesbohrer H. Droop Richmond E. Hembrough Harold Heath Gray G. Schuhmacher Jens O. Neuberg A. Jacquerod Tourpaïan Contzen G. T. Baxter H. W. Storkweather Société Roubaisienne d'Eclairage 《Analytical and bioanalytical chemistry》1919,58(2):70-78