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61.
F. Ricoul A. Subrenat O. Joubert A. Le Gal La Salle 《Journal of Solid State Electrochemistry》2018,22(9):2789-2800
The aim of this work is to study the reactivity of a Ni-YSZ-based solid oxide fuel cell (SOFC) fueled with gaseous mixtures having the same composition as the syngas issued from a fixed-bed downdraft and staged gasification pilot. The syngas issued from the gasifier contains some ppm(v) of H2S, and in order to adapt the purification process, the influence of this compound on the Ni-YSZ-based SOFCs is evaluated at 600 and 850 °C. The influence of H2S depends on fuel composition, temperature but also of current density. In H2–N2 mixtures and only at 600 °C, a significant decrease of cell performances is observed for H2S?>?4.5 ppm(v). For H2–CO–CO2–N2 mixtures, the influence is more important since a small decrease of performance can be observed for 1 ppm(v) of H2S even at 850 °C. Nevertheless, at 600 °C, it is possible to avoid damage by limiting the current density. Aging experiments, realized at 750 °C, show that the influence of 1 and 2 ppm(v) of H2S is more important during the first 20 h and is reversible: at this temperature, after poisoning with 1 ppm(v) of H2S during 72 h, the cell recovers 91% of its initial power density after 100 h in pure hydrogen, and after subsequent poisoning with 2 ppm(v) of H2S during 77 h, the cell recovers 94% of its initial power density after 168 h in pure hydrogen. 相似文献
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63.
A systematic analysis of the electrostatic interaction between 27 natural DNA base pairs was carried out, based on ab initio correlated wave functions and the topology of the electron density. Using high rank multipole moments we show that the atomic partitioning of the interaction energy contains many substantial contributions between distant atoms. Profiles of cumulative energy versus internuclear distance show large fluctuations and provide an electrostatic fingerprint of the partitioning of interaction energy in a complex. A quantified comparison between each pair of energy profiles, one for each base pair, makes clear that there is no correlation between the total base pair interaction energy and the shape of the profile. In other words, base pairs with similar interaction energy are not stable for the same reasons in terms of atomic partitioning. In summary, simple rules to rationalize the pattern of energetic stability of naturally occurring base pairs in terms of subsets of atoms are elusive. Our work cautions against inappropriate use of Jorgensen's secondary interaction hypothesis. 相似文献
64.
Haines TJ Bionta RM Blewitt G Bratton CB Casper D Claus R Cortez BG Errede S Foster GW Gajewski W Ganezer KS Goldhaber M Jones TW Kielczewska D Kropp WR Learned JG Lehmann E LoSecco JM Matthews J Park HS Price LR Reines F Schultz J Seidel S Shumard E Sinclair D Sobel HW Stone JL Sulak L Svoboda R van der Velde JC Wuest C 《Physical review letters》1986,57(16):1986-1989
65.
Marie-Florence Grenier-Loustalot Marguerite Gillard Frdrric Joubert Philippe Grenier 《Journal of polymer science. Part A, Polymer chemistry》1993,31(11):2839-2854
We have synthesized and studied the ring dehydration mechanisms and kinetics of polyamic acid models in solution and in the solid state using 13C-NMR (solid and liquid), HPLC, FTIR, and x-ray diffraction. Results obtained in solution show the role of temperature, catalysts, and the basicity of the amine in ring dehydration mechanisms and kinetics, as well as conformation and intramolecular bonds in the amic acid bond in the solid state. © 1993 John Wiley & Sons, Inc. 相似文献
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68.
Observation of a neutrino burst in coincidence with supernova 1987A in the Large Magellanic Cloud 总被引:1,自引:0,他引:1
Bionta RM Blewitt G Bratton CB Casper D Ciocio A Claus R Cortez B Crouch M Dye ST Errede S Foster GW Gajewski W Ganezer KS Goldhaber M Haines TJ Jones TW Kielczewska D Kropp WR Learned JG LoSecco JM Matthews J Miller R Mudan MS Park HS Price LR Reines F Schultz J Seidel S Shumard E Sinclair D Sobel HW Stone JL Sulak LR Svoboda R Thornton G van der Velde JC Wuest C 《Physical review letters》1987,58(14):1494-1496
69.
A new series of perovskite-like compounds CMn7O12 have been synthesized under high pressure and high temperature conditions. C is a large divalent or trivalent cation such as Ca, Cd, Sr, La and Nd. The structures of the quenched materials have been determined from powder X-ray data. They are distortions of the NaMn7O12 cubic structure. The [C2+Mn3+3](Mn3+3Mn4+)O12 compounds are trigonal (). The C2+ and Mn3+ as well as the Mn3+ and Mn4+ cations are ordered on the corresponding A and B sites of the perovskite structure, respectively. The [C3+Mn3+3] (Mn3+4)O12 compounds are monoclinic (). In these compounds the order exists only in the A sites. It is shown that the lower symmetry may be the result of a cooperative Jahn-Teller effect of the Mn3+ cations occupying the B sites. 相似文献
70.
An alternating direction scheme on a nonuniform mesh for reaction-diffusion parabolic problems 总被引:1,自引:0,他引:1
Clavero C; Jorge JC; Lisbona F; Shishkin={paragraph} GI 《IMA Journal of Numerical Analysis》2000,20(2):263-280
In this paper we develop a numerical method for two-dimensionaltime-dependent reaction-diffusion problems. This method, whichcan immediately be generalized to higher dimensions, is shownto be uniformly convergent with respect to the diffusion problems.This method, which can immediately be generalized to higherdimensions, is shown to be uniformly convergent with respectto the diffusion parameter. 相似文献