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991.
Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 3, pp. 34–35, March, 1992.  相似文献   
992.
993.
A complete theoretical analysis is presented of the operation of a magnetoelastic amorphous metal low-frequency magnetic field sensor. This directional magnetometer is a hybrid device consisting of a piezoelectric plate, a field-annealed amorphous metal ribbon, and a viscous fluid, and it exhibits a low-frequency magnetic field detection level of 8.0 pT/√Hz at 1.0 Hz. The sensor may also be configured as a first- and second-order gradiometer. The device analysis focuses on the influence of the constituent materials on the magnetometer performance, identifying potential noise sources and optimal design parameters. This analysis may be applied to a variety of magnetoelastic amorphous metal sensors, e.g. stress, strain, and torque sensors, and is also useful in research concerning fundamental aspects of magnetoelasticity. Experimental data are presented demonstrating the performance of magnetometers constructed with amorphous metal ribbons exhibiting striped and closure domain structures  相似文献   
994.
Asbestos fibres, of the chrysotile variety, and chopped carbon fibres were pretreated by an in-situ polycondensation technique eventually resulting in a polyamide coating on the fibre surface. Ionomer based composites containing either carbon or asbestos fibres in random in plane fibre orientation were prepared, and the influence of this coating process on the tensile properties was investigated. It was found that for the asbestos-filled composites the presence of the nylon 6,6 interlayer improves the tensile performance, especially at moderate polyamide depositions. This is not the case with the pretreated carbon-filled composites for which carbon fibres with higher polyamide contents are preferred. Combinations of the treated asbestos fibres with carbon and/or aramid fibres may be used to reduce the asbestos content in asbestos-only based engineering plastics.  相似文献   
995.
Mendeleev All-Union Metrology Research Institute. Translated from Atomnaya Énergiya, Vol. 73, No. 5, pp. 393–397, November 1992.  相似文献   
996.
Deuterated scintillators (NE230) can provide, without time-of-flight, usable neutron energy spectra for neutrons E n⩾1 MeV. The authors have assembled and calibrated several of these detectors and used them in experiments searching for d+d fusion-neutron emission (En, 2.5 MeV) in Pd+D 2O electrolysis and Ti+D2 adsorption at LN temperatures. The detectors yielded direct fusion-neutron spectra and set limits in the Pd+D and Ti+D experiments of <7×10-24 fusion n/s/dd pair and <3×10-24 fusion n/s/dd pair respectively. In addition, these detectors have been used for in-beam accelerator experiments requiring coincidence between fast neutrons and scattered ions  相似文献   
997.
998.
We present a new particle method for the simulation of the semiconductor Boltzmann equation—the weighted particle method. This method differs from the Monte-Carlo method by the approximation of the collision operator—we allocate each particle a weight which varies in time according to the collision integral. This integral is evaluated by means of a quadrature formula, which does not require the use of random numbers. The aim of this paper is to show that this method gives accurate results on physically relevant problems. Linear as well as non-linear collision integrals can be handled the same way by this method. Precise representations of the distribution functions are available, which allow a good insight into the physical processes. In this paper, we only consider the homogeneous field model with an emphasis on the collision operator. Numerical results are presented with a comparison with the Monte-Carlo method.  相似文献   
999.
Even if it were true that SAR (synthetic aperture radar) ocean surface imagery provides a perfect noiseless representation of ocean surface wave height, each spectrum computed from such imagery would be but a single realization of the ensemble-mean ocean spectrum. There would be sampling variability associated with the parameters of dominant wave number and propagation direction extracted from such a spectrum. The present study addresses two questions: (i) what statistical distribution is applicable to the spectra of SAR ocean images? and (ii) what are the consequences of such statistics on the precision with which wave number and propagation direction can be extracted? An examination is made of spectra computed from ocean imagery acquired during the SIR-B (Shuttle Imaging Radar-B) mission  相似文献   
1000.
The number of circuit design iterations due to electrostatic discharge (ESD) failures increases with the complexity of VLSI technologies and their shrinking. In this paper, we show how TCAD and ESD SPICE modeling can be used to solve ESD protection issues in an analog CMOS technology.  相似文献   
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