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61.
Clover detector has been used as a Compton polarimeter to measure the linear polarization of γ-rays produced in heavy ion
fusion reaction. The polarization sensitivity of the clover detector has been measured over γ-ray energies ranging from 386
to 1368 ke V. The E1 multipolarity of the 1117 keV transition in 99Rh has been established using this polarimeter. This has resulted in the assignment of negative parity to the band head at
3710 keV in 99Rh. 相似文献
62.
An alternative approach is suggested to determine the spot-size of a multi-mode laser beam. It has been shown by simulations
that the suggested approach can give the beam quality factor and characteristic radius with less than 5% error. Unlike the
power content method, the proposed method is applicable to the beams even with diameter one tenth of the CCD size. The new
approach has been applied to a multi-mode diode laser output and it is shown that the ABCD matrix analysis can be used for beam propagation, with the measured parameters of the laser. 相似文献
63.
Mittal K.C. Rohatgi V.K. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1988,16(6):601-605
A technique for controlling the voltage and current pulse duration of a gigawatt relativistic electron beam (REB) was investigated. The pulse duration of a beam of 250 keV and 10 kA was controlled from 60 ns to 10 ns by injecting gases (air,, argon, and hydrogen) into the diode gap at a pressure ranging from 10-5 torr to 10-1. The observed dependence of the pulse duration on the nature and pressure of the gas is explained in terms of volume ionization of the gas by beam electrons. It is concluded that the pulse duration is governed by the time at which the plasma density created by the beam reaches a critical value of the order of beam electron number density 相似文献
64.
Applied Biochemistry and Biotechnology - Ethanol is commercially produced by bioconversion and by hydration of ethylene. Bioconversion has the significant advantage that utilization of nonrenewable... 相似文献
65.
66.
T. E. Cowan B. R. Beck J. H. Hartley R. H. Howell R. R. Rohatgi J. Fajans R. Gopalan 《Hyperfine Interactions》1993,76(1):135-142
The development of a high density cryogenic pure positron plasma trap at the LLNL positron beam facility opens new possibilities
for antihydrogen research. We discuss a planned measurement of the three-body collisional recombination rate in magnetized
plasmas, a possible antihydrogen atomic beam experiment, and other applications of pure positron plasmas. 相似文献
67.
A. Yu. Ivochkin A. A. Karabutov M. L. Lyamshev I. M. Pelivanov U. Rohatgi M. Subudhi 《Acoustical Physics》2007,53(4):471-477
An optoacoustic technique for diagnostics of residual stress in metals is proposed. The theoretical part of the technique employs acoustoelastic relations establishing a linear relationship between the biaxial residual stress and the relative variation of the velocity of longitudinal ultrasonic waves. The experimental technique is based on laser excitation of nanosecond ultrasonic pulses at the surface of samples under investigation and their detection with a high time resolution. Distributions of the relative variation of longitudinal wave velocities due to the presence of residual stress in the samples are obtained. 相似文献
68.
Nosonovsky M Hejazi V Nyong AE Rohatgi PK 《Langmuir : the ACS journal of surfaces and colloids》2011,27(23):14419-14424
The lotus effect involving roughness-induced superhydrophobicity is a way to design nonwetting, self-cleaning, omniphobic, icephobic, and antifouling surfaces. However, such surfaces require micropatterning, which is extremely vulnerable to even small wear rates. This limits the applicability of the lotus effects to situations when wear is practically absent. To design sustainable superhydrophobic surfaces, we suggest using metal matrix composites (MMCs) with hydrophobic reinforcement in the bulk of the material, rather than only at its surface. Such surfaces, if properly designed, provide roughness and heterogeneity needed for superhydrophobicity. In addition, they are sustainable, since when the surface layer is deteriorated and removed due to wear, hydrophobic reinforcement and roughness remains. We present a model and experimental data on wetting of MMCs. We also conducted selected experiments with graphite-reinforced MMCs and showed that the contact angle can be determined from the model. In order to decouple the effects of reinforcement and roughness, the experiments were conducted for initially smooth and etched matrix and composite materials. 相似文献