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排序方式: 共有1391条查询结果,搜索用时 375 毫秒
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N. E. Wijeysundera M. N. A. Hawlader Chan Wee Boon Andy M. Kamal Hossain 《International Journal of Refrigeration》2004,27(5):1997
An ice slurry generation system was developed using direct contact heat transfer between water and the coolant, Fluroinert FC-84. The location of the coolant nozzle is an important design consideration to avoid clogging due to freezing of water. An ice fraction of up to about 40 percent was obtained with the nozzle located at the bottom of the ice slurry tank and the jet directed upwards into the water. Two simplified model were developed to extract the heat transfer coefficient between the coolant drops and the water. The first model requires as input the average drop diameter and the residence time while the second model uses the measured drop diameter distribution. The estimated heat transfer coefficients are much smaller than those computed using single-sphere correlations. 相似文献
3.
R Beyer H Burghardt R Reich E Thomas T Gessner D.R.T Zahn 《Microelectronics Reliability》1998,38(2):144
Thin SiO2 and SiOxNy layers were grown on silicon using Rapid Thermal Processing (RTP) in either O2 or N2O ambient. Subsequent annealing or nitridation was performed in order to improve the electrical stability. The composition of the films, in particular the incorporation of nitrogen and hydrogen, has been studied. We obtained the distribution of states at the Si/insulator interface through the evaluation of CV measurements and investigated the charge trapping in the layers analysing the voltage–time behaviour during Fowler–Nordheim constant current injection. Furthermore, assuming a trap assisted tunneling mechanism, the influence of near interface trap states on the current voltage characteristic was used to derive an effective insulator state distribution. 相似文献
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C Oddoux E Reich F Axelrod A Blumenfeld C Maayan S Slaugenhaupt J Gusella H Ostrer 《Canadian Metallurgical Quarterly》1995,15(9):817-826
Familial dysautonomia (FD), a recessively inherited disease, has been mapped to chromosome 9q31. Highly polymorphic dinucleotide repeat markers flanking the genetic locus and at the same genetic location have been identified. We describe the prenatal diagnosis of FD using linkage and linkage disequilibrium analyses with these markers. Twelve families were analysed for informativeness and of these, seven went on to have prenatal testing (a total of eight fetuses tested). All of these fetuses were predicted to be heterozygous unaffected (FD carriers). Seven fetuses have come to term and are normal. In the absence of a recombinant proband, a panel of three proximal and three distal markers is sufficient to provide informative flanking markers and an 87-96 per cent likelihood of a highly predictive test. In an additional family at 1:4 risk for FD, no DNA was available from the propositus. This family was analysed using linkage disequilibrium to the #18 allele of the tightly linked marker D9S58 in conjunction with linkage analysis using data from two unaffected children. Prenatal diagnosis in this family indicated an affected fetus. 相似文献
7.
A. Krell T. Reich A. Beger G. A. Gogotsi Y. L. Groushevsky 《Journal of Materials Science》1991,26(17):4637-4642
At room temperature, SiO2 additions may increase the fracture toughness, K
IC, by diminishing the tetragonal phase contents to about 50%, but with ground surfaces the influence on strength is small.
A pronounced decrease in strength is observed with rising temperature in the high toughness region from 20°C to M
s, the starting temperature for martensitic transformation. Beyond M
s at lower toughness, the strength behaviour is very similar to nontransforming alumina ceramics, and an even modest increase
of the silicate concentration intensively promotes propagation-controlled failure in the brittle creep region (> 900°C) and
inelastic deformation. With less than 1% amorphous grain boundary phases, damage-free superplasticity is restricted to small
strains of less than 10%. The significance of high-temperature data for tool applications is considered by cutting tests with
high feeding rates. 相似文献
8.
Les Hatton Andy Wright Stuart Smith Gregg Parkes Paddy Bennett Robert Laws 《Software》1988,18(4):301-329
The portability of software has become a major commercial issue in recent times. Such portability does not come easily, as few if any computer languages are really portable in practice. An additional complicating factor, especially in the commercial environment, is that the resulting software must be efficient. This paper describes the design and successful implementation of a 500,000+ line portable FORTRAN 77 package for the processing of seismic data. The package exhibits demonstrably high efficiency on a wide variety of machines from minicomputers to the largest supercomputers. Experiences gained during this exercise throw much light on the integration of the various thought processes which occur during the software engineering cycle, especially the notion of locality. 相似文献
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The experimental determination and computer simulation of the micro‐segregation accompanying the solidification of alloys continues to be a subject of much academic and industrial interest. Both are subject to progressively more sophisticated analyses, and a discussion is offered regarding the development and practical use of such studies. Simple steels are particularly difficult targets for such work: solidification does not end conveniently in a eutectic, the rapid diffusion particularly in the delta‐ferrite phase obscures most evidence of what had occurred at the micro‐scale during solidification, and one or more subsequent solid state phase transformations further obscure such details. Also, solidification at the micro‐scale is inherently variable: the usual, dendrite morphologies encountered are, after all, instabilities in growth behaviour, and therefore such variability should be expected. For questions such as the relative susceptibility of different grades to particular problems, it is the average, typical behaviour that is of interest, whereas for other questions such as the on‐set of macro‐segregation, the local variability is paramount. Depending on the question being asked, and indeed the accuracy with which validatory data are available, simple pseudo‐analytical equations employing various limiting assumptions, or sophisticated models which remove the need for most such limitations, could be appropriate. This paper highlights the contribution to such studies of various collaborative research forums with‐in the European Union with which the author is involved. 相似文献