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51.
Morpholine is a base of moderate strength, comparable with that of ammonia, and capable of forming -onium-type salts. Extensive studies [1,2] have been made on the thermal stability of ammonium perchlorate because of its technological use as an oxidant in solid state rocket propellants. The preparation, characterization and thermal behaviour of morpholinium perchlorate are reported in this note. The study was followed by XRD, IR, TG, DTA and mass spectral techniques. 相似文献
52.
Dynamic mechanical studies of cholesteric liquid crystalline substances in the solid state have been reported using Du Pont's Dynamic Mechanical Analyser, DMA-981. All the substances showed multiple transitions. There is no common transition though the parent structure was similar in the compounds. These weak transitions are not detectable by DSC and hence appear to be second order transitions possibly arising due to rotation of the molecules around the long axis. Alternatively the lattice defects may also be responsible for such transitions. 相似文献
53.
Abstract SO4 2?/SnO2 was employed for the acylation of a variety of alcohols, phenols, and amines under solvent‐free conditions at room temperature. This method showed preferential selectivity for acetylation of the amino group in the presence of a hydroxyl group. The reported method is simple, mild, and environmentally viable, using several other acid anhydrides at room temperature. 相似文献
54.
We study CP violation in a multi-Higgs doublet model based on aS
3×Z
3 horizontal symmetry. We consider two mechanisms for CP violation in this model: a) CP violation due to complex Yukawa couplings;
and b) CP violation due to scalarpseudoscalar mixings. We find that the predictions for ε′/ε, CP violation in B decays and
the electric dipole moments of neutron and electron are different between these two mechanisms. These predictions are also
dramatically different from the minimal Standard Model predictions. 相似文献
55.
S. Deshpande G. Hofstra R. A. Fletcher E. W. Abrahamson 《Photochemistry and photobiology》1991,54(3):485-488
Light scattering relaxation spectrophotometry has proven to be a useful technique to monitor rapid cytophysical changes in chloroplast suspensions brought about by flash illumination. This paper compares the Mg-ATP dependent light scattering behaviour of cholorplasts isolated from control and triazole-treated wheat seedlings. Our results suggest that triazole-treatment enhances Mg-ATP dependent activity. This same enhancement in control chloroplasts can be brought about by introducing potassium ion in the presence of valinomycin. Therefore, the potassium ion might account for part of the stress resistance conferred by triazole treatment. 相似文献
56.
V. K. Deshpande 《Ionics》2004,10(1-2):20-26
The electrical conductivity results of lithium borosilicate glasses with addition of Li2SO4 and LiCl have been critically analyzed. In general, it is observed that the factors viz. lithium fraction, fLi and the number of non-bridging oxygens (NBOs) govern the ionic conductivity in the lithium conducting glasses. For the same
fLi, the presence of mixed formers in the glass gives higher conductivity compared to that of the glass with only one former.
Thus the competitive network of glass in mixed former systems provides higher mobilities for lithium ions and hence high ionic
conductivity. The addition of Li2SO4 and LiCl in the lithium borosilicate glasses gave enhancement in the conductivity. However, the mechanism of enhancement
in conductivity is different in the two glass systems. The comparison of the result of binary, ternary and quaternary glass
systems suggests that in general, the decrease in activation energy, increase in fLi and increase in NBOs gives rise to enhancement in conductivity. For the same value of fLi the higher conductivity is exhibited by glasses with lower value of K (K=SiO2/B2O3).
Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003. 相似文献
57.
Chuen‐Jinn Tsai Jyh‐Shyan Lin C. G. Deshpande Li‐Chun Liu 《Particle & Particle Systems Characterization》2005,22(5):293-298
An aerosol charge analyzer has been constructed to measure the charge distribution of NaCl particles generated in the laboratory. A radioactive electrostatic charge neutralizer utilizing Po‐210 was used to neutralize the electrostatic charge of the particles. The atomization technique was used to generate NaCl particles with diameters of 0.2 to 0.8 μm, while the evaporation and condensation method was adopted to generate particles of 0.01 to 0.2 μm in diameter. The experimental data demonstrates that the absolute average particle charge depends on the particle diameter, and is higher than that calculated by the Boltzmann charge equilibrium for particles within the range of 0.2 to 0.8 μm. The charge increases with decreasing NaCl concentration. When these particles are neutralized using the Po‐210 neutralizer, it is found that the electrostatic charge reaches the Boltzmann charge equilibrium. For 0.01 to 0.2 μm NaCl particles generated using the evaporation and condensation method, test results show that the absolute average particle charge is higher than that calculated by the Boltzmann charge equilibrium for particles larger than 0.03 to 0.05 μm in diameter, while it is lower than that predicted by the Fuchs theory [1], for particles smaller than 0.03 to 0.05 μm. However, after charge neutralization, particles with diameter above 0.05 μm reach the Boltzmann charge equilibrium condition, and the charges for particles with diameters of 0.010 to 0.05 μm, agree well with Fuchs' theory. 相似文献
58.
Z-scan studies on porphyrin derivative 总被引:2,自引:0,他引:2
K. Kandasamy K. Divakar Rao Rekha Deshpande P.N. Puntambekar Bhanu P. Singh Shankar J. Shetty T.S. Srivastava 《Applied physics. B, Lasers and optics》1997,64(4):479-484
Received: 10 January 1996 / Revised version: 15 June 1996 相似文献
59.
It has been shown in this paper that a test proposed by Barlow and Doksum (1972) based on the exponential scores statistic for testing exponentiality against increasing failure rate distributions is consistent for the much wider class of harmonic new better than used in expectation distributions. 相似文献
60.
We present a grand unified model of the strong, electromagnetic and weak interactions based on a local SU(8)L×SU(8)R gauge theory which possesses a global U(8)L × U(8)R invariance. We break the symmetry down to the standard SU(3)C × SU(2)L × U(1) model, with the proton remaining stable and the left-handed neutrinos obliged to remain massless. A novel feature of our model is the simultaneous absence of both strong CP violations and of axions. 相似文献