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31.
A. Ghoshal P. Mandal 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(2):251-258
An exponential correlated basis set is tested within the framework
of multi-channel Schwinger variational principle in the momentum space.
It is found that inclusion of only the
positron-electron correlation in the basis set is
enough to obtain accurate results for all significant partial
waves for ground state positronium
formation in positron-hydrogen collisions at low and intermediate energies (6.856–75 eV).
Results are in conformity with other accurate
variational and non-variational calculations as well as observed data available in the
literature. 相似文献
32.
Cd(OH)2 and CdO nano/micro crystals were synthesized in ethanol-water medium using cadmium foil as a source under solvothermal condition. The experimental parameters such as ratio of ethanol to water, concentration of NaOH and synthesis temperature all play important role in determining the size, shape and crystalline phase of the products. The products were characterized by X-ray diffraction and scanning electron microscopy. Nano/micro crystals of CdO were also achieved by thermal treatment of Cd(OH)2 crystals in air at different temperatures. 相似文献
33.
B. Karrer G. Ghoshal 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,62(2):239-245
There has been a considerable amount of interest in recent years on the robustness of networks to failures. Many previous
studies have concentrated on the effects of node and edge removals on the connectivity structure of a static network; the networks are considered to be static in the sense that no compensatory measures are allowed for recovery of
the original structure. Real world networks such as the world wide web, however, are not static and experience a considerable
amount of turnover, where nodes and edges are both added and deleted. Considering degree-based node removals, we examine the
possibility of preserving networks from these types of disruptions. We recover the original degree distribution by allowing
the network to react to the attack by introducing new nodes and attaching their edges via specially tailored schemes. We focus
particularly on the case of non-uniform failures, a subject that has received little attention in the context of evolving
networks. Using a combination of analytical techniques and numerical simulations, we demonstrate how to preserve the exact degree distribution of the studied networks from various forms of attack. 相似文献
34.
35.
Summary An attempt is made to study effective electron mass in quantum well wires of ternary chalcopyrite semiconductors by formulating
a new 1D dispersion relation, within the framework of thek·p formalism considering the anisotropies in the band parameters. It is found, taking quantum well wires ofn-CdGeAs2 as an example, that the effective Fermi level mass depends on the subband index due to the combined influence of crystal-field
splitting parameter and the anisotropic spinorbit splitting parameters, respectively. The masses increase with increasing
carrier degeneracy and decreasing film thickness, respectively. In addition, the well-known results for the corresponding
parabolic energy bands have been derived as special cases of the generalized formulations. 相似文献
36.
Swadesh Kumar Ghoshal Sankar Sengupta 《Journal of Quantitative Spectroscopy & Radiative Transfer》1980,23(5):499-502
The modified Morse potential function known as the Hulburt-Hirschfelder function has been used for the Ar2 molecule using experimental values for the spectroscopic constants. The consistency of this potential is checked by recalculating the vibrational levels using Cashion's method. The results are satisfactory. The potential may be useful for calculating the anharmonic properties of crystalline argon. 相似文献
37.
38.
In the absence of an experimentally determined 3D structure of CDK4 (Cyclin-Dependent Kinase 4), QSARs (Quantitative Structure Activity Relationship) have been explored to rationalize binding affinity in terms of physicochemical and structural parameters. Further, docking on a homology model of CDK4 validated the derived QSARs and predicted the binding mode of this series of inhibitors. Relevant parameters and leave-one-out (LOO) cross-validation (q (2)) as well as an external test set validation (r (2) pred) judged the statistical significance and predictive ability of the models. Docking enabled a better understanding of protein-ligand interaction and provided a mechanistic interpretation in terms of physicochemical characteristics. It identified a unique hydrogen bonding between the imidazole of His-95 and the pyridine nitrogen in the ligand. It rationalized the need for R 2 substituents to be bulky and polar, while the substituent at R 8 to be hydrophobic and comparatively less steric. It also explained why at R 6 a variety of substituents are tolerated and how the presence of methyl at R 5 enhances binding affinity. 相似文献
39.
Phase inversion method is applied to prepare flat sheet asymmetric polymeric membranes from homogeneous solution of 12 wt% polysulfone (PSf) with two different solvents--N-methyl-2-pyrrolidone (NMP) and dimethyl acetamide (DMAc). 5.0 wt% polyethylene glycol (PEG) of three different molecular weight (400, 6000, and 20,000 Da) is used as the polymeric additives in the casting solution. Membranes are characterized by two different techniques viz. scanning electron microscopy (SEM) and gas permeation tests. Finally, the results of both the techniques are compared with those calculated from pure water permeation tests using Hagen-Poiseuille equation. It is found that though the values obtained from all the techniques vary from each other, their trend with increase in molecular weight of PEG seems to be the same. It is seen that when molecular weight of PEG increases from 400 to 20,000 Da, the mean pore size of the prepared membranes decreases, while the porosity and pore density show an increasing trend; the pressure normalized gas flux rises significantly and the thickness of the top layer of the prepared membrane sheet increases. 相似文献
40.
Two new copper(II) complexes {[Cu(H2biim)(H2O)(suc)](H2O)}n (1) and {[Cu(H2biim)2(H2O)][Cu(H2biim)2(glut)](glutH)(NO3) · 2.5H2O}n (2) (H2biim, 2,2′-biimidazole; suc, succinate dianion; glut, glutarate dianion) have been synthesized and characterized by single crystal X-ray diffraction study and thermal analysis. Complex 1 comprises of 1D zigzag coordination polymers, elongated along the crystallographic b-axis, connected through H-bonding and face-to-face π–π interactions to form a robust 3D network. Whereas complex 2 is built up of bischelated [Cu(II)(H2biim)2]2+ units, glutarate and nitrate anions and water molecules, held together through an extensive H-bonded system. The resulting 3D supramolecular architecture defines channels which are filled by lattice water molecules and disordered nitrate anions. 相似文献