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291.
Abnormally high heats, exceeding 1600 kJ/mol (16 eV) per molecular oxygen, are generated by interaction of the oxygen with the hydrogen adsorbed on gold surfaces at 125 °C. The highest heats were observed during the interactions of fine gold particles supported on titanium oxide, approaching 1700 kJ/mol for three consecutive 100 nmol pulses of O2 interacting with the adsorbed hydrogen atoms. The heats rapidly decrease after the hydrogen is consumed. It was also observed that the interactions of the gold particles with pure oxygen in the presence of noble gases, such as argon and helium, produced the heats markedly higher than those observed in the absence of noble gases. The abnormally high heats revealed by this work reach values from 3.5 to 6.1 times higher than the heats of formation of gaseous water from molecular hydrogen and oxygen. 相似文献
292.
293.
M. Braglia 《Il Nuovo Cimento D》1996,18(6):705-725
Summary It is shown how the general analytical expression of an autoregression, whose stationary solution has an arbitrary given form,
can be obtained. The central-limit theorem is used to state a correspondence between autoregression and relevant diffusion
equation which not only permits to give analytical form to the stationary distribution of a given autoregression, but also
to obtain appropriate series expansions of its fundamental solution and the exact relaxation constants. The interest of the
analysis in the context of Monte Carlo simulations of relaxation and steady-state processes is discussed. The procedure is
illustrated by two examples of interest in the field of ionized gases. 相似文献
294.
A. Rossani A. M. Scarfone 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,50(1-2):295-298
Test particles interact with a medium by means of a
bimolecular reversible chemical reaction. Two species are assumed to
be much more numerous so that they are distributed according to
fixed distributions: Maxwellians and Dirac's deltas. Equilibrium and
its stability are investigated in the first case. For the second
case, a system is constructed, in view of an approximate solution. 相似文献
295.
Yu-Zhi Wang 《Optics & Laser Technology》1993,25(6):367-370
An in situ mass-spectrometric sampling technique has been developed for lifetime studies of TEA CO2 lasers. Using the new technique, an analysis of the gas components of a TEA CO2 laser during its lifetime has been performed. The results show that the laser output pulse energy was strongly influenced by the oxygen concentration inside the device. 相似文献
296.
钯-抗坏血酸基体改进剂平台石墨炉原子吸收光谱法测定贻贝标样中的砷 总被引:1,自引:0,他引:1
本实验建立了钯-抗坏血酸基体改进剂平台石墨炉原子吸收光谱法测定贻贝中砷的方法。研究了基体改进剂氯化钯、抗坏血酸用量对测定的影响,比较了氯化钯-抗坏血酸、氯化钯、硝酸镍三种基体改进剂及平台石墨管、普通石墨管在测定贻贝中砷的灵敏度。方法的相对标准偏差为3.2%,回收率在97.8%—107.4%之间,检出限为12.0ng/mL。 相似文献
297.
Mean permeability coefficients for CO2, O2, N2, and CH4 in seven types of 6FDA polyimides with branched or extended diamine moieties were determined at 35.0°C (95.0°F) and at pressures up to 10.5 atm (155 psia). In addition, solubility coefficients for CO2, O2, N2, and CH4 in six of these polyimides were determined at 35.0°C and at 6.8 atm (100 psia). Mean diffusion coefficients for the six gas/polyimide systems were calculated from the permeability and solubility data. The relationships between the chemical structure of the polyimides, some of their physical properties (glass transition temperature, mean interchain spacing, specific free volume), and their gas permeability, diffusivity, and solubility behavior are discussed. The 6FDA polyimides studied here exhibit a considerably lower selectivity for the CO2/CH4 and O2/N2 gas pairs than 6FDA polyimides with short and stiff aromatic diamines with comparable CO2 and O2 permeabilities. © 1993 John Wiley & Sons, Inc. 相似文献
298.
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300.
Cellular automata offer a simple way to simulate flow in complex geometries. The algorithm computes flow by tracking the paths of individual particles of a simple lattice gas. An advantage of this approach is that many of the traditional problems of conventional numerical techniques in dealing with complex boundaries are avoided. In particular explicit front tracking of moving interfaces in two-phase flow is not necessary. On the other hand, some problems appear that are specific to lattice gas models. In this paper we propose solutions to these problems. Furthermore, we give an overview of the current status of lattice gas algorithms with respect to applications in fluid flow. 相似文献