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31.
《Spectrochimica Acta Part B: Atomic Spectroscopy》1986,41(10):1089-1113
An improved, continuous-flow ultrasonic nebulizer equipped with a desolvation system for generating dehydrated aerosol particles prior to their injection into analytical inductively coupled plasmas is described. Results of a critical evaluation of the performance of the nebulizer-desolvation system are also presented. Compared to the commonly used pneumatic nebulizers studied in this work, the ultrasonic version described in this paper provided superior powers of detection, ranging from factors of 5–50, and yielded comparable to superior short and long term reproducibility for dilute acid and high salt content solutions. Clean out times for the ultrasonic nebulizer were marginally longer, by 15–20 s, than those observed for pneumatic nebulizers. “Memory effects” and “desolvation interferences” were generally reducible to negligible proportions through the application of various expediencies discussed in this paper. When substantial changes in concomitant concentrations caused measurable interelement effects, the magnitude of these effects tended to be slightly higher for the ultrasonic system. However, when the samples destined for ultrasonic nebulization were diluted by factors of ~ 10, which corresponds approximately to the superiority of the nebulization efficiency of the ultrasonic nebulizer, the magnitudes of the interelement effects were comparable. 相似文献
32.
《Superlattices and Microstructures》1986,2(4):363-368
By repeated deposition of several Å of Ni below 100 °C and subsequent annealing to typically 350 °C, thin continuous NiSi2-layers have been grown epitaxially on Si (111). Thicknesses exceeding ∼- 70 Å require a different procedure due to the increasing importance of lateral growth, spoiling the layer quality. We show that MBE at substrate temperatures above 500 °C is not a viable technique to increase the thickness of the ultrathin layers. The reason is found to lie in the insufficient stability of the NiSi2 templates, disintegrating into islands at temperatures above 500 °C. Perfectly smooth layers up to 1000 Å have, however, been grown by a new method in which alternate layers of Ni and Si (typically 1 Å and 4 Å respectively) are deposited onto the initial template at substrate temperatures between 350 °C and 380 °C. 相似文献
33.
《International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry》1986,27(4):287-295
The selective adsorption of blood group antibodies can be realized on immobilized red bloods cells on polycationic supports. Different supports containing dimethyl amino ethyl methacrylate (DMAEMA) has been obtained according to various proceedings : grafting on PVC, bulk polymerization, suspension polymerization.Physical characteristics and specific adsorption yields have been compared.This study has led to perfect specific and performant immunoadsorbents. 相似文献
34.
35.
《Chemical physics》1986,108(3):417-428
The molcules NSF, NSO−, NSCl, HNSF+, HNSO, CH3NSF+, CH3NSO are investigated at the SCF level and partly with inclusion of electron correlation effects. Equilibrium geometries and relative stabilities of isomers and conformers are reported. Structure constants and relative energies are discussed in connection with the molecular electronic structure as characterized by the results of population analyses. 相似文献
36.
《Chemical physics》1986,101(2):279-289
The phenomenon of laser-induced hole filling (LIHF) is reported and discussed in detail for rhodamine 640, Nd3+, Pr3+ and the mixed system of rhodamine 560 and cresyl violet. Importantly, LIHF does not show any spectral diffusion (i.e. broadening). Possible mechanisms (thermal heating, site reversion and energy transfer) involved in LIHF are discussed and are argued to have insignificant contribution. A tentative model is developed to explain these results. The model basically invokes a connectivity between spatially removed extrinsic (impurity) two-level systems (TLS) via an ensemble of intrinsic (host) TLS (the glassy state). Additionally, a correlation between impurity excitation energies and absolute glassy state energies is imposed. 相似文献
37.
《European Journal of Operational Research》1986,24(2):288-294
This paper shows how the notion of ‘relative importance of attributes’ can be defined within the framework of the noncompensatory approach to multiple criteria decision making. The problem of weights then appears as a problem of functional representation of relations. We state some theoretical results concerning this problem and outline a practical decision-aid (Tactic) based on the ideas introduced in the paper. 相似文献
38.
《European Journal of Operational Research》1986,23(3):301-309
The paper is concerned with a two-level corporate model. At the lower level, divisions produce for the external market. They require certain technical services. The divisions are coordinated by a central unit at the top level. The central unit must determine the integral plan of technical services i.e. firm-wide optimal make-or-buy decisions, without having complete information on the divisions.We present a decomposition-based planning procedure during which the central unit gathers information to derive an optimal make-or-buy decision while allocating the costs of internal technical services.The model formulation has substantial significance for the real world: A similar organizational structure, information dispersal among subunits and coupling of divisions and departments is commonly observed in existing firms. The resulting planning procedure can be interpreted in terms of planning and budgeting in real organizations. 相似文献
39.
《European Journal of Operational Research》1986,23(3):391-395
A problem of the maximization of the ratio of a concave function to a convex function is considered, subject to an upper bound on a single convex constraint function; all these functions are assumed to be differentiable. An incremental algorithm is defined, which solves the problem parametrically for different values of the constraint function by the solution of a set of ordinary first order differential equations. If K is the number of variables in the problem and B(K) is an upper bound—dependent of K —of the time needed to evaluate any function value or any first or second order derivative, the complexity of the algorithm is of the order O[(B(K)K + K)a], where a is the number of integration steps applied in the solution of the differential equations. In particular, a cost-effectiveness resource allocation problem with separable functions is solved numerically in a time of the order O[Ka] if B(K) is independent of K; an example of such a problem is given with analytically solvable differential equations. 相似文献
40.
《Nuclear Physics A》1986,452(4):573-590
By means of a streamer chamber exposed to the LEAR antiproton beams, the total reaction cross sections, the charged-prong multiplicity distributions and lower limits for the production of negative pions and Ks0 in the p̄-Ne interaction were measured at 19.6, 48.7 and 179.6 MeV. Annihilation was found to be dominant over all other non-elastic p̄-Ne processes. An analysis of Ne and other nuclei data in the frame of the Glauber theory allowed us to determine the ratio between the p̄-n and the p̄-p cross sections. An analysis in the light of INC model predictions allowed us to show up events which can be interpreted as annihilations having occurred deeply inside the nuclei. 相似文献