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1.
Electron transport in a three-dimensional quantum wire is analyzed by taking into account electron scattering by a single point impurity. It is shown that the magnetoconductance plotted versus chemical potential μ has narrow peaks and closely located peaks separated by a dip when the scattering length is positive and negative, respectively. The peaks lie near the conductance steps. The thermopower plotted versus μ has narrow peaks and closely located peaks separated by a dip when the scattering length is positive and negative, respectively. 相似文献
2.
A new preconditioned conjugate gradient (PCG)-based domain decomposition method is given for the solution of linear equations
arising in the finite element method applied to the elliptic Neumann problem. The novelty of the proposed method is in the
recommended preconditioner which is constructed by using cyclic matrix. The resulting preconditioned algorithms are well suited
to parallel computation. 相似文献
3.
V. A. Margulis 《Journal of Experimental and Theoretical Physics》2004,99(3):633-639
The nonlinear absorption of electromagnetic radiation by electrons in a quantizing magnetic field is investigated. The inclusion of multiphoton processes is shown to result in additional peaks in the absorption curve. The shape and arrangement of these peaks were found. The absorption is shown to depend on the electric field strength in the electromagnetic wave nonlinearly and nonmonotonically. The results obtained are in good agreement with experimental data. 相似文献
4.
Huang X Margulis CJ Li Y Berne BJ 《Journal of the American Chemical Society》2005,127(50):17842-17851
When supercritical CO2 is dissolved in an ionic liquid, its partial molar volume is much smaller than that observed in most other solvents. In this article we explore in atomistic detail and explain in an intuitive way the peculiar volumetric behavior experimentally observed when supercritical CO2 is dissolved in 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim+] [PF6(-)]). We also provide physical insight into the structure and dynamics occurring across the boundary of the CO2 ionic liquid interface. We find that the liquid structure of [Bmim+] [PF6(-)] in the presence of CO2 is nearly identical to that in the neat ionic liquid (IL) even at fairly large mole fractions of CO2. Our simulations indicate, in agreement with experiments, that partial miscibilities of one fluid into the other are very unsymmetrical, CO2 being highly soluble in the ionic liquid phase while the ionic liquid is highly insoluble in the CO2 phase. We interpret our results in terms of the size and shape of spontaneously forming cavities in the ionic liquid phase, and we propose that CO2 occupies extremely well-defined locations in the IL. Even though our accurate prediction of cavity sizes in the neat IL indicates that these cavities are small compared with the van der Waals radius of a single carbon or oxygen atom, CO2 appears to occupy a space that was for the most part a priori "empty". 相似文献
5.
M. A. Margulis O. B. Ovchinnikov I. M. Margulis 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2006,80(6):986-990
It is shown experimentally that a laser-induced breakdown of a liquid is accompanied by chemical reactions initiated by radicals and excited species formed in the spark. It is found that, in water, the laser-induced breakdown is accompanied by the dissociation of water and dissolved nitrogen molecules with the formation of HNO2 and HNO3, while, in a FeSO4 aqueous solution, by the Fe2+ → Fe3+ oxidation reaction. It is assumed that the mechanism of the process is analogous to that of the action of ionizing radiations and the chemical action of ultrasonically induced cavitation (it is proposed that this mechanism of chemical action of a laser-induced spark proposed be termed indirect). Energy yields of these reactions are found to be of the same order of magnitude as for sonochemical redox reactions. It is shown that the laser-induced breakdown of an aqueous solution of maleic acid is accompanied by its stereoisomerization into fumaric acid, a process catalyzed by small amounts of an alkyl bromide. It is established that, for the formation of fumaric acid in a laser-induced spark, the energy yield is about five orders of magnitude higher than that typical of the above-mentioned redox reactions in the laser-induced spark. 相似文献
6.
M. A. Margulis 《High Energy Chemistry》2004,38(3):135-142
Sonochemistry is one of the most intensively developing areas of high energy chemistry in both theoretical and applied aspects. There has been considerable progress in sonochemistry: many sonochemical reactions in nonaqueous systems were revealed, power yields for some sonochemical reactions and the initial power yields of ultrasonic degradation of water were determined, single-bubble sonoluminescence was discovered, the formation of radicals in an ultrasound field was detected by spin trapping, a method for the generation of powerful low-frequency (of the order of 10–200 Hz) cavitation fields was developed and chemical and physicochemical effects in these fields were revealed, high-performance hydrodynamic apparatus were designed and sonoluminescence and chemical effects were observed in such systems, ultrasound-induced oscillating reactions were discovered, and the generalized electric theory of cavitation processes was elaborated. 相似文献
7.
The hsp70 family of major stress proteins is composed of several different members exhibiting similar structural and functional properties. In order to obtain an antiserum with wide epitope reactivity, rabbits were immunized with a mixture of native and denatured hsp70 purified from bovine muscle by ATP-affinity chromatography. Screening for antibody specificity was performed by a "sandwich" enzyme linked immunosorbent assay (ELISA). Immunoprecipitation and immunoblotting analyses demonstrated that the polyclonal antiserum obtained by us and a monoclonal antibody raised against a different preparation of antigen recognized the same determinant on the native hsp70 molecule (inducible form). With a different specificity the polyclonal antiserum recognized only the denatured monomers of the other members of the hsp70 family. These results are discussed in relation to the immunological features of the hsp70 molecule and to the development of an immunoassay for the detection of hsp70 in cell and tissue extracts. 相似文献
8.
T. Szitó J. G. Kiss GY. I. Garab L. A. Mustárdy Á. Faludi-Dániel 《Photochemistry and photobiology》1984,40(1):113-117
Abstract Orientation pattern of the Qy absorption and emission dipoles of chlorophyll a were studied in wild type Scenedesmus obliquus and in mutants deficient in chlorophyll b and carotenoids. Fluorescence polarization ratio at –140°C and linear dichroism at 25°C were measured in whole cells and thylakoids aligned in polyacrylamide gel. Unlike normal thylakoids, mutants displayed fluorescence polarization ratios significantly lower than 1.0 and showed a negative LD signal around 672 nm, indicating the tendency of the Qy dipoles to tilt out from the membrane plane. Such an orientation pattern can also be artificially induced by treating normal thylakoids with linolenic acid. 相似文献
9.
S. Kadyrov D. Kleinbock E. Lindenstrauss G. A. Margulis 《Journal d'Analyse Mathématique》2017,133(1):253-277
Singular systems of linear forms were introduced by Khintchine in the 1920s, and it was shown by Dani in the 1980s that they are in one-to-one correspondence with certain divergent orbits of one-parameter diagonal groups on the space of lattices. We give a (conjecturally sharp) upper bound on the Hausdorff dimension of the set of singular systems of linear forms (equivalently, the set of lattices with divergent trajectories) as well as the dimension of the set of lattices with trajectories “escaping on average” (a notion weaker than divergence). This extends work by Cheung, as well as by Chevallier and Cheung. Our method differs considerably from that of Cheung and Chevallier and is based on the technique of integral inequalities developed by Eskin, Margulis and Mozes. 相似文献
10.
G. A. Margulis 《Combinatorica》1982,2(1):71-78
We give an explicit construction of regular graphs of degree 2r withn vertices and girth ≧c logn/logr. We use Cayley graphs of factor groups of free subgroups of the modular group. An application to low density codes is given. 相似文献