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排序方式: 共有67条查询结果,搜索用时 62 毫秒
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This paper is devoted to the existence and nonexistence of positive solutions for a semilinear elliptic system involving critical Sobolev exponent and weights. We study the effect of the behavior of weights near their minima on the existence of solutions for the considered problem. 相似文献
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C. P. Burgess M. Frank C. Hamzaoui 《Zeitschrift fur Physik C Particles and Fields》1996,70(1):145-158
We compute, at one loop, the CP-violating anomalous trilinear gauge-boson form factors which couple theW (or theZ) to the photon and theZ. In order to see which form factors are generated by which types of underlying interactions, we work with as general an underlying model as is possible. After identifying which form factors can arise at one loop in a completely general renormalizable model of spin-half and spin-zero particles, we provide explicit formulae for the induced form factors in a very broad class of such models. Our results include some previous calculations as special cases, and we identify errors in some of these. 相似文献
25.
Nicolas Charalambakis George Chatzigeorgiou Yves Chemisky Fodil Meraghni 《Continuum Mechanics and Thermodynamics》2018,30(1):1-51
In this paper, a review of papers on mathematical homogenization of dissipative composites under small strains and on the interplay between homogenization procedure and dissipation due to mechanical work is presented. Moreover, a critical survey on the links between mathematical homogenization and computational homogenization is attempted. 相似文献
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The structure of (E)-N-[(E)-3-[(lR,2R)-2-(3,4-dibromo-phenyl)-l-fluro-cyclopropyl]- allylidene]-2-0-tolyl-acetamide (C21HIsONFBrz, Mr = 479.18) has been determined by X-ray single- crystal diffraction and theoretical calculations to establish the configuration, stereochemistry and a stable conformation of the molecule. The compound crystallizes in the monoclinic space group P21/c, a = 28.3452(10), b = 4.9311(10), c = 14.257(2) A, fl = 102.7654(10), V = 1943.5(5) A3 and Z = 4. The structure has been refined to the final R = 0.05 for the observed structure factors with 1 〉 30(/). Theoretical calculations in the ground state have been carried out for the compound studied using the Hartree-Fock (HF) and density functional theory (DFT) (B3LYP) with 6-31G(d,p) basis sets. The results show that the studied compound prefers the keto form. The compound involves intra- and intermolecular hydrogen bonding of C-H.-.O and C-H-..F types, which further stabilize the structure and display a trans configuration for the C=N and C=C double bonds. The calculated results show that the predicted geometry can well reproduce the structural parameters. 相似文献
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Souheil Behij Ahmed Hichem Hamzaoui Ridha Rokbani Adel M’nif 《Russian Journal of Inorganic Chemistry》2011,56(6):991-998
Solubility of sodium, potassium and calcium sulfates and chlorides in 28% ammonia solution was determined through monitoring
conductivity measurements and kinetics of solids dissolution as a function of temperature and stirring time. The major findings
of the present study show that Na2SO4 and K2SO4 solutions conductivity follow straight linear segments with different slopes. However, in case of NaCl, KC1, CaCl2 and CaSO4 · 2H2O, conductivity curves were continuous, monotonous and reach constants maximum values. The hypothesis of complex formation
or dissolution via intermediaries such as NaNH4SO4 and KNH4SO4 salts seams to be true, through X-ray diffraction study of resulting deposits. Furthermore, the dissolution rates at 25°C
of potassium and calcium chlorides in ammonia solution are higher than that reported in the literature for water. In fact,
ammonia significantly reduces the solubility of K2SO4; conversely, a slight increase in this parameter was observed for CaSO4. 相似文献
30.
N. H. Arabi A. Iratni H. El Hamzaoui B. Capoen M. Bouazaoui M. Halbwax J. P. Vilcot S. Bastide 《Journal of Sol-Gel Science and Technology》2012,62(1):24-30
In this paper, antireflective TiO2 thin films have been prepared on single crystal silicon, and textured polycrystal silicon by sol–gel route using the dip-coating
technique. The thickness and the refractive index of the films have been optimised to obtain low reflexion in the visible
region, by controlling both the concentration of the titanium isopropoxide (Ti(iOPr)4), and the annealing temperature. We showed that the use of a TiO2 single layer with a thickness of 64.5 nm, heat-treated at 450 or 300 °C, reduces the reflection on single crystal silicon
at a level lower than 3% over the broadband spectral ranges 670–830 nm and 790–1010 nm, respectively. In order to broaden
the spectral minimum reflectance as much as possible, we have proposed to texture polycrystal silicon wafers, and to coat
these wafers by a TiO2 single layer with a thickness of 73.4 nm. In this case, the reflectance has been reduced from 27 to 13% in the spectral range
460–1000 nm. 相似文献