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991.
Hemanshu Bhatt Kimberly Y. Donaldson D. P. H. Hasselman Kenneth Chyung Mark P. Taylor 《Journal of the American Ceramic Society》1991,74(6):1463-1465
A study concerning the effect of fiber orientation on the thermal conductivity of a uniaxial carbon-fiber-reinforced borosilicate glass was conducted. For thin specimens, and thick specimens with specimen sides cut parallel to the fiber direction, the dependence of thermal conductivity on fiber orientation showed excellent agreement with theoretical behavior predicted for a composite infinite in extent. In contrast, the thermal conductivity data for rectangular thick specimens fell well below the data for the thin and angled specimens. For fiber orientation of 45° and higher, at which the heat was directed toward the side of the specimen rather than across, the thermal conductivity values showed excellent agreement with theoretical behavior predicted for a finite composite strip with insulated sides. 相似文献
992.
Translated from Kibernetika, No. 1, pp. 40–43, January–February, 1988. 相似文献
993.
The degradation behaviour of Kodar [poly(1,4-cyclohexylene dimethyl-eneterephthalate)] was investigated in air using thermogravimetry, differential thermal analysis and wide angle X-ray diffraction studies. The rates of crystallization and degradation were influenced by thermal exposure and polychromatic irradiation (Λ > 290 nm) for different time intervals. The crystallinity changes (Xc%) and activation energies (ΔE) for the systems have been determined. 相似文献
994.
995.
Postoperative feeding with a special-purpose foodstuff Ovolact proved superior to tube feeding in patients on after treatment following surgical correction of congenital jaw defects. This was evident from assessment of anthropometric and protein metabolism parameters. Nitrogen metabolism underwent positive changes reflecting the product value for maintenance of protein status of the above patients. Therefore, Ovolact can make more effective postoperative rehabilitation in jaw reconstruction. 相似文献
996.
997.
The 320C30 is a fast processor with a large memory space and floating-point-arithmetic capabilities. The authors describe the 320C30 architecture in detail, discussing both the internal organization of the device and the external interfaces. They also explain the pipeline structure, addressing software-related issues and constructs, and examine the development tools and support. Finally, they present examples of applications. Some of the major features of the 320C30 are: a 60-ns cycle time that results in execution of over 16 million instructions per second (MIPS) and over 33 million floating-point operations per second (Mflops); 32-bit data buses and 24-bit address buses for a 16M-word overall memory space; dual-access, 4 K×32-bit on-chip ROM and 2 K×32-bit on-chip RAM; a 64×32-bit program cache; a 32-bit integer/40-bit floating-point multiplier and ALU; eight extended-precision registers, eight auxiliary registers, and 23 control and status registers; generally single-cycle instructions; integer, floating-point, and logical operation; two- and three-operand instructions; an on-chip DMA controller; and fabrication in 1-μm CMOS technology and packaging in a 180-pin package. These facilitate FIR (finite impulse response) and IIR (infinite impulse response) filtering, telecommunications and speech applications, and graphics and image processing applications 相似文献
998.
O. G. Goman V. I. Karplyuk M. I. Nisht 《Journal of Engineering Physics and Thermophysics》1988,54(2):148-152
The method of discrete vortices is used for a numerical investigation of the nonlinear unsteady problem of passage of an axisymmetric body through a coaxial thin-walled cylindrical tube of finite length.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 54, No. 2, pp. 216–221, February, 1988. 相似文献
999.
Dental amalgams are based on a broad spectrum of materials differing in their chemical composition, metallurgical treatment, and in the way the initial alloys powders are prepared. In addition to their chemical composition, amalgams based on various powders differ in both their microstructure and the amount of mercury needed for preparation. All these facts may affect electrochemical processes occurring during their interaction with oral fluids, and also mercury release. While verifying the effect of the technology used for the preparation of the high‐copper ternary alloy powder on the properties of resulting amalgams, this study aimed at the mechanism of their interaction with a model saliva solution as well as mercury release was included. Measurements were done in a model saliva solution using standard electrochemical methods and exposition measurements. The interaction of individual types of amalgams with artificial saliva did not reveal any significant differences. The free corrosion potential of all these amalgams in an aerated solution settled in the range of values in which tin oxidation, resulting in a layer of insoluble corrosion producsts, turned out to be the dominant anodic process. The rate of mercury release was the lowest for amalgams based on a gas‐atomized alloy. The highest rate of mercury release, and also its dependence on time, was exhibited by lathe‐cut powder based amalgam. In addition to different volume fraction of the Ag‐Hg phase and the level of its tin alloying, this different behaviour may be explained by differences in the rate at which a layer of tin corrosion products acting as a barrier to mercury release is formed. 相似文献
1000.
As an alternative to a symbolic interpretation of transitivity in the discriminative performance of pigeons, a modified reinforcement theory (value transfer theory) was proposed by L. von Fersen et al (see record 1991-29523-001). Its novel assumption was that the value of the negative member of a pair of stimuli with which an animal is trained is enhanced by the value of the positive member of the pair. In this article, that assumption is shown to be unnecessary. All of the transitivity data for pigeons can be simulated with a simple conditioning model developed for honeybees that retains the conventional independence assumption. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献