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81.
介绍了一种用于冰箱检测的新型测试系统,并在WIN98环境下用VB6.0实现该系统软件。该系统可以同时对四台冰箱的温度参数及其中一台冰箱的耗电量进行检测,该系统具有成本低,性能稳定的优点。 相似文献
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Carl A. Soderstrom Patricia C. Dischinger Gordon S. Smith J.Richard Hebel David R. McDuff David A. Gorelick Timothy J. Kerns Shiu M. Ho Kathleen M. Read 《Accident; analysis and prevention》1997,29(6):715-721
A structured in-depth interview employing standardized criteria was used to determine the prevalence of lifetime and current alcohol dependence (alcoholism) in unselected consecutive patients admitted to a regional Level I trauma center. Of 629 patients, 157 (25.0%) were current alcoholics at the time of injury. An additional 87 (13.8%) were diagnosed as lifetime non-current alcoholics. There was no significant difference in the rates of current alcohol dependence among patients injured in vehicular crashes (23.5%), other unintentional trauma victims (29.3%), and those injured as a result of violence (24.6%). Of BAC + (blood alcohol concentration positive) patients, 54.5% were current alcoholics. However, 14.4% of alcohol-negative patients were also diagnosed as alcohol dependent. 相似文献
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87.
A new phantom is described which simulates the human cardiac anatomy for applications in ultrasound imaging, ultrasound Doppler, and color-flow Doppler imaging. The phantom consists of a polymer left ventricle which includes a prosthetic mitral and aortic valve and is connected to a mock circulatory loop. Aerated tap water serves as a blood simulating fluid and ultrasound contrast medium within the circulatory loop. The left ventricle is housed in a Lexan ultrasound visualization chamber which includes ultrasound viewing ports and acoustic absorbers. A piston pump connected to the visualization chamber by a single port pumps degassed water within the chamber which in turn pumps the left ventricle. Real-time ultrasound images and Doppler studies measure flow patterns through the valves and within the left ventricle. 相似文献
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89.
E. Smith 《Mechanics of materials : an international journal》1994,17(4):369-378
The paper determines the elastically equivalent softening zone size RE for an elastic-softening material when there is a semi-infinite crack in a remotely loaded infinite solid; the parameter RE plays a central role in size effect expressions that are used to correlate the maximum loads that can be sustained by solids having different dimensions. The stress (p) versus displacement (v) softening law considered is that for which P = pc for oc and P = ; qpc = p* for λδc< v <δc. Particular attention is focussed on the case where the parameters λ and q are both small. Such a softening law simulates the softening behaviour of plain concrete, where there is an initially rapid softening to a low stress value at a small displacement, followed by a long tail that is associated with a low stress. The paper shows that the behaviour of a material with such a softening law can be conveniently analysed by assuming that there is a non-zero stress intensity (KIC) at the crack tip followed by a constant stress p* within the softening zone;
, where Eo is the reduced modulus and GI = λpcδc is the contribution to the specific fracture energy arising from the initially rapid softening region. Analysis of a specific model demonstrates the viability of this approach by showing that there is consistency with the proposed size effect expressions based on RE. 相似文献
90.
Iskander M.F. Smith R.L. Andrade A.O.M. Kimrey H. Jr. Wal L.M. 《Microwave Theory and Techniques》1994,42(5):793-800
Microwave sintering of ceramics in multimode cavities, particularly the use of picket-fence arrangements, has recently received considerable attention. Various types of ceramics have been successfully sintered and, in some cases, a desirable and unique “microwave effect” has been observed. At present, various aspects of the sintering profess such as preparation of sample sizes and shapes, types of insulations, and the desirability of including a process stimulus such as SiC rods are considered forms of art and highly dependent on human expertise. The simulation of realistic sintering experiments in a multimode cavity may provide an improved understanding of critical parameters involved and allow for the development of guidelines towards the optimization of the sintering process. In this paper, we utilize the FDTD technique to model various geometrical arrangements and material compatibility aspects in multimode microwave cavities and to simulate realistic sintering experiments. The FDTD procedure starts with the simulation of a field distribution in multimode microwave cavities that resembles a set of measured data using liquid crystal sheets. Also included in the simulation is the waveguide feed as well as a ceramic loading plate placed at the base of the cavity 相似文献