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991.
Hsiaotao T. Bi 《中国颗粒学报》2005,3(6):395-399
Electrostatic charges are generated by particle-wall, particle-particle and particle-gas contacts in gas-solids transport lines and fluidized bed reactors. High particle charge densities can lead to particle agglomeration, particle segregation, fouling of reactor walls and internals, leading to undesirable by-product and premature shut-down of processing equipment. In this paper, the charge generation, dissipation and segregation mechanisms are examined based on literature data and recent experimental findings in our laboratory. The particle-wall contact charging is found to be the dominant charge generation mechanism for gas-solids pneumatic transport lines, while bipolar charging due to intimate particle-particle contact is believed to be the dominant charge generation mechanism in gas fluidized beds. Such a bipolar charging mechanism is also supported by the segregation patterns of charged particles in fluidized beds in which highly charged particles tend to concentrate in the bubble wake and drift region behind rising bubbles. 相似文献
992.
V. A. Storozhenko 《International Applied Mechanics》2006,42(11):1311-1321
The paper addresses issues of real-world operation of a device designed to experimentally identify the principal central axes
of inertia of an arbitrary inhomogeneous rigid body. The effect of external and internal dissipation on the stability and
accuracy of the device is studied
__________
Translated from Prikladnaya Mekhanika, Vol. 42, No. 11, pp. 131–143, November 2006. 相似文献
993.
994.
995.
Seismic wave imaging in visco-acoustic media 总被引:2,自引:0,他引:2
Realistic representation of the earth may be achieved by combining the mechanical properties of elastic solids and viscous liquids. That is to say, the amplitude will be attenuated with different frequency and the phase will be changed in the seismic data acquisition. In the seismic data processing, this effect must be compensated. In this paper, we put forward a visco-acoustic wave propagator which is of better calculating stability and 相似文献
996.
Transfer of charge through metal-support interfaces leads to an increase in the activity of mixed catalysts. In this review, we consider the main aspects of research aimed at studying processes that create and allow interphase transfer of highly excited (hot) charge carriers in supported catalysts, and discuss the effect of these phenomena on catalytic activity. 相似文献
997.
Fan Hou Liuwei Zhao 《International journal of environmental analytical chemistry》2016,96(12):1105-1116
Chlorothalonil and azoxystrobin, as efficient and broad-spectrum fungicides, are two widely used fungicides to control downy mildew and anthracnose on cabbage. For the safe and rational use of these two pesticides on cabbage, their residues and dissipation were studied under field conditions. The trial results showed that chlorothalonil and azoxystrobin residues were affected by the frequency and dosage of application, and the weather condition post-application. Chlorothalonil and azoxystrobin dissipated rapidly in cabbage with the mean half-live of 1.7 and 0.4 days at three geographical experimental plots in China, respectively. The terminal residues of chlorothalonil and azoxystrobin in cabbage at harvest time were all below the maximum residue limit (MRL, 6 mg kg?1 for chlorothalonil and 5 mg kg?1 for azoxystrobin) established by Codex Alimentarius Commission. It suggested that this formulation of chlorothalonil and azoxystrobin (560 g L?1, SC) may be safer under the recommended dosage. Given that in China no MRL has been set for chlorothalonil and azoxystrobin in cabbage, this study could provide a guidance for establishing MRL, and the safe and rational use of these two pesticides. 相似文献
998.
A. Barletta S. Lazzari E. Magyari 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2008,59(6):1039-1056
Steady combined forced and free convection is investigated in a vertical channel having a wall at rest and a moving wall subjected
to a prescribed shear stress. The moving wall is thermally insulated, while the wall at rest is kept at a uniform temperature.
The analysis deals with the fully–developed parallel flow regime. The governing equations yield a boundary value problem,
that is solved analytically by employing a power series expansion of the velocity field with respect to the transverse coordinate.
It is shown that the nonlinear interplay between buoyancy and viscous dissipation may determine the existence of dual solutions
of the boundary value problem corresponding to fixed values of the applied shear stress on the moving wall and of the hydrodynamic
pressure gradient. It is shown that a nontrivial fully separated flow may occur such that the hydrodynamic pressure gradient
is zero and the shear stress vanishes on both walls.
E. Magyari: On leave from Institute of Building Technology, ETH – Zürich 相似文献
999.
《Surface Science Reports》2021,76(3):100532
Fundamental mechanisms for energy conversion and dissipation on surfaces and at interfaces have been significant issues in the community of surface science. Electronic excitation in exothermic chemical reactions or photon absorption involves the generation of energetic or hot electrons that are not in thermal equilibrium via non-adiabatic electronic excitation. A number of experimental and theoretical studies have demonstrated the influence of excited hot electrons on atomic and molecular processes, and it is a key moderator in the surface energy conversion process. The charge transfer through the metal-oxide interfaces has a significant impact on catalytic performance in mixed metal-oxide catalysts. In order to understand the influence of hot electrons and metal-oxide interfaces on the surface reactions, various detection schemes of exoelectron detection, including metal-insulator-metal and metal-semiconductor Schottky diodes, have been developed. Catalysts coupled with surface plasmons exhibit peculiar catalytic performance related to hot electron flow. In this review, we outline recent research efforts to relate hot electron flow with surface reactions occurring at metal-oxide interfaces. We report recent studies on the observation of hot electrons and the correlation between hot electrons and catalytic activity and selectivity on metallic surfaces. We show recent results from studies of surface reactions on nanocatalysts coupled with surface plasmons, where hot electron transport is the key process in energy dissipation and conversion processes. 相似文献
1000.
YE Wei 《中国物理C(英文版)》2010,34(1)
Using a Langevin model, we calculate post-saddle proton and a-particle multiplicities as a function of the post-saddle dissipation strength (β) for the heavy systems ~(234)Cf, ~(240)Cf, ~(246)Cf and ~(240)U. We find that, with increasing isospin of the system, the sensitivity of post-saddle light charged-particle multiplicities to β decreases considerably and, moreover, for 240U the charged-particle multiplicities are no longer sensitive to β. These results suggest that in order to determine the post-saddle friction strength more accurately by measuring the multiplicities of pre-scission protons and a particles, it is best to populate those heavy compound systems with low isospin. 相似文献