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41.
Takashi Minoshima Yosuke Matsumoto Takanobu Amano 《Journal of computational physics》2011,230(17):6800-6823
We present a new numerical scheme for solving the advection equation and its application to Vlasov simulations. The scheme treats not only point values of a profile but also its zeroth to second order piecewise moments as dependent variables, for better conservation of the information entropy. We have developed one-and two-dimensional schemes and show that they provide quite accurate solutions within reasonable usage of computational resources compared to other existing schemes. The two-dimensional scheme can accurately solve the solid body rotation problem of a gaussian profile for more than hundred rotation periods with little numerical diffusion. This is crucially important for Vlasov simulations of magnetized plasmas. Applications of the one- and two-dimensional schemes to electrostatic and electromagnetic Vlasov simulations are presented with some benchmark tests. 相似文献
42.
在激光能量130 mJ(靶面),脉宽60 fs,波长800 nm,对比度1∶10-6,激光与靶法线成45°夹角,P偏振,靶面激光峰值功率密度约为7.0×1017 W·cm-2,无预脉冲的条件下,采用电子谱仪与经γ标准源标定的LiF热释光探测器(TLD)相配合,测量了飞秒激光-薄膜靶相互作用中产生的超热电子能谱。根据所测的能谱,推算出超热电子的产额和激光能量转化为超热电子能量的效率,在靶法线方向分别为1.19×1010/sr和4.55%/sr,在激光反射方向分别为1.83×109/sr和0.76%/sr。结果显示,不同方向的超热电子产额和激光转化效率有所不同,原因在于激光-等离子体相互作用产生的超热电子构成各向异性的分布。 相似文献
43.
44.
Joshi Shrikant V. Park Jin Y. Taylor P. R. Richardson L. S. 《Plasma Chemistry and Plasma Processing》1985,5(2):143-161
Plasma Chemistry and Plasma Processing - A new integral mean diffusivity is proposed for the calculation of the mass transfer rate around a small particle immersed in a thermal plasma gas.... 相似文献
45.
D.T. Petkie B.P. Winnewisser R.A.H. Butler F.C. De Lucia 《Journal of Quantitative Spectroscopy & Radiative Transfer》2005,92(2):129-141
The results of millimeter and submillimeter wave rotational spectroscopy are used to simulate the complex structure of the 2ν9-ν9 and ν5-ν9 hot bands. The comparison data were obtained with a high-resolution Bruker FTIR. The combination of the quality of these data and the complexity of the spectra of these interacting states represents a stringent test for the simulation. It is shown that the agreement is very good and that this approach is generally advantageous. From this simulation, the ratios of the transition dipole moments for the 2ν9-ν9 and ν5-ν9 hot bands with respect to the ν9 fundamental band were found to be 1.38(11) and 0.67(20), respectively. Using these results, the calculated integrated band intensities for the hot bands at were determined to be and . These results were used to successfully simulate high-resolution stratospheric spectra obtained from a balloon flight of the FIRS-2 spectrometer. The more general problem of the rotation-vibration database and the optimal use of both microwave and infrared data to define it is discussed. It is concluded that it is best if the combination of data takes place at the level of the original spectra. 相似文献
46.
Geetha Rajappan 《Journal of Molecular Spectroscopy》2004,224(2):107-113
The rovibrational spectrum of 2ν9 band of CD3CCH is overlapped by two prominent hot bands identified as (2ν90+ν10±1)(E)←ν10±1(E) and 3ν9±1(E)←ν9±1(E), where ν10 and ν9 are the degenerate CCC and CCH bending fundamental vibrations, respectively. Assignment of lines to the transitions of these hot bands were carried out with the help of the high-resolution spectra recorded at ∼195 K and at room temperature. Molecular parameters for these hot bands have been obtained from the rotational analysis of the partially resolved K-structure lines. Only Q-head of the third hot band , originating from the lower 2ν10 state could be identified. 相似文献
47.
The presence of dust grains is a common phenomenon in the space environment. Grains can be charged by many different processes (e.g., photoemission, attachment of electrons/ions, the secondary emission, etc.). If the grain's surface potential becomes high enough, one can observe field emission of ions or electrons. We are trapping a single dust grain in a Paul trap, expose it to a low-energy electron beam, and investigate the evolution of its charge-to-mass ratio with respect to the energy of primary electron beam. We use micron-sized (D = 2–11 m) glass grains and charge them up to -300 V of surface potentials; it corresponds to the electric field strength of about 108 V/m. Analysis of the charging/discharging processes has shown that (1) the effect of the field enhanced secondary emission is negligible in the case of insulators and (2) the effective work function for electron field emission from charged insulators is as low as 1 eV. 相似文献
48.
N.L. Tsintsadze P.K. Shukla L. Stenflo 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,23(1):109-115
The electroweak coupling between intense neutrino beams and strongly degenerate relativistic dense electron-positron magnetoplasmas
is considered. The intense neutrino bursts interact with the plasma due to the weak Fermi interaction force, and their dynamics
is governed by a kinetic equation. Our objective here is to develop a kinetic equation for a degenerate neutrino gas and to
use that equation to derive relativistic magnetohydrodynamic equations. The latter are useful for studying numerous collective
processes when intense neutrino beams nonlinearly interact with degenerate, relativistic, dense electron-positron plasmas
in strong magnetic fields. If the number densities of the plasma particles are of the order of 1033 cm-3, the pair plasma becomes ultra-relativistic, which strongly affects the potential energy of the weak Fermi interaction. The
new system of equations allows several neutrino-driven streaming instabilities involving new types of relativistic Alfvén-like
waves. The relevance of our investigation to the early universe and supernova explosions is discussed.
Received 11 September 2002 Published online 4 February 2003
RID="a"
ID="a"Permanent address: Department of Physics, Tbilisi State University, Chavchavadze 3, Tbilisi 38028, Georgia.
RID="b"
ID="b"Also at the Department of Plasma Physics, Ume? University, 90187 Ume?, Sweden; and the Center for Interdisciplinary Plasma Science,
Max-Planck Institut für Plasmaphysik und extraterrestrische Physik, Postfach 1312, 85741 Garching, Germany. e-mail: ps@tp4.ruhr-uni-bochum.de
RID="c"
ID="c"Permanent address: Department of Plasma Physics, Ume?University, 90187 Ume?, Sweden. 相似文献
49.
50.
通过对不同激光条件产生的等离子体进行Thomson散射实验诊断,发现在距靶面为150 μm的临界密度面内,离子声波双峰强度出现明显的不对称性,而且强峰的位置发生了转移:当等离子体的电子温度较高时,强峰出现在短波方向;当等离子体电子温度较低时,强峰出现在长波方向.光的拉曼散射效应对应地解释了离子声波的双峰结构、双峰强度不对称性及强峰出现的位置.建立了光的拉曼散射与电子的Thomson散射的对应关系. 相似文献