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171.
Following the recent work of Chandleret al on quasi probability distributions for spin-1/2 particles, we show that polarized light can be interpreted in terms of trivariate
probability distributions in two different ways by choosing the variates to correspond to (i) the co-ordinates on the Poincare
sphere, (ii) the components of the spin operator of the photon. In either case, it is shown that the Margenau-Hill procedure
leads to probability mass functions while the Wigner-Weyl approach leads to probability density functions and the well-known
Stokes parameters are also realised as appropriate averages with respect to these distribution functions. 相似文献
172.
M. P. Ramachandran 《Applied mathematics and computation》1990,40(2):105-116
End conditions are shown to be generated from the conditions on the derivatives of a class of piecewise cubic interpolatory polynomial approximations to the given function near the two end points. The new approach is illustrated by obtaining a number of end conditions, which include those discussed with special interest by Behforooz and Papamichael. 相似文献
173.
Hema Ramachandran 《Pramana》2002,58(2):313-323
Experimental realization of mirrorless lasers in the last decade have resulted in hectic activity in this field, due to their
novelty, simplicity and ruggedness and their great potential for application. In this article, I will review the various developments
in this field in roughly chronological order, and discuss some possible applications of this exciting phenomenon, also termed
as ‘random lasing’. 相似文献
174.
P. N. Ramachandran 《Periodica Mathematica Hungarica》1982,13(4):335-340
175.
176.
Abstract— Oxidation of acetone under Baeyer-Villager conditions produces a new species which is capable of epoxidizing olefins. It is suggested that this intermediate is acetone carbonyl oxide or its isomer dimethyldioxirane. 相似文献
178.
We investigate the asymmetries arising due to electromagnetic interactions in largeP
T pion inclusive processes. The hardqcd processes that contribute to such asymmetries areq+g→q+γ,q+q→g+γ etc. which are suspected to be substantial, as indicated by theqcd predictions for a significant and increasingγ/π
o ratio at largeP
T. We calculate the expected isospin related asymmetries and propose tests that might detect them. Our estimates indicate that
the effects are much smaller than may be naively expected. We also observe a remarkable scaling of asymmetries in the variableP
T/(s)1/2. 相似文献
179.
Stephen P Vijayan R Bhat A Subbarao N Bamezai RN 《Journal of computer-aided molecular design》2008,22(9):647-660
Pyruvate phosphate dikinase (PPDK) is the key enzyme essential for the glycolytic pathway in most common and perilous parasite Entamoeba histolytica. Inhibiting the function of this enzyme could control the wide spread of intestinal infections caused by Entamoeba histolytica in humans. With this objective, we modeled the three dimensional structure of the PPDK protein. We used templates with 51% identity and 67% similarity to employ homology-modeling approach. Stereo chemical quality of protein structure was validated by protein structure validation program PROCHECK and VERIFY3D. Experimental proof available in literature along with the in silico studies indicated Lys21, Arg91, Asp323, Glu325 and Gln337 to be the probable active sites in the target protein. Virtual screening was carried out using the genetic docking algorithm GOLD and a consensus scoring function X-Score to substantiate the prediction. The small molecule libraries (ChemDivision database, Diversity dataset, Kinase inhibitor database) were used for screening process. Along with the high scoring results, the interaction studies provided promising ligands for future experimental screening to inhibit the function of PPDK in Entamoeba histolytica. Further, the phylogeny study was carried out to assess the possibility of using the proposed ligands as inhibitors in related pathogens. 相似文献
180.
Pasumansky L Collins CJ Pratt LM Nguyên NV Ramachandran B Singaram B 《The Journal of organic chemistry》2007,72(3):971-976
The influence of temperature and solvent effects on the reduction and amination mechanisms of iodomethane by lithium N,N-diisopropylaminoborohydride (iPr-LAB) was examined in varying concentrations of THF and dioxane. The reactions of benzyl chloride and trimethylsilyl chloride with iPr-LAB in THF were also studied. The amination of iodomethane is favored over reduction at low and room temperatures in pure THF and with increasing the amount of dioxane in THF. At higher temperatures, the reduction reaction appears to compete with the amination. In dioxane solvent, however, iodomethane yields exclusively the amination product regardless of temperature. On the other hand, reduction by iPr-LAB to the aminoborane is the only product observed in THF when benzyl chloride and trimethylsilyl chloride are used. To understand the solvent effects on the product distribution, ab initio and density functional theory (DFT) calculations were used to examine the mechanisms of reduction and amination of chloromethane and bromomethane by lithium dimethylaminoborohydride (LAB) in THF and dioxane. The results of these calculations show that the relative reaction barrier heights are significantly affected by the nature of the coordinated solvent molecule and thus lend support to the experimental observations. 相似文献