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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
S. M. Logvinkov G. D. Semchenko S. V. Tishchenko V. I. Toshinskii V. A. Borovaya I. N. Opryshko 《Glass and Ceramics》1996,53(1-2):33-34
Compositions and technologies are suggested for preparing highly efficient catalyst blocks with a honeycomb structure to be used for reducing nitrogen oxides with ammonia in flue gases from thermal power plants. The blocks have high structural strength and catalytic activity. 相似文献
992.
We describe a ray method for analysis of the geometric and optical characteristics of two-layer fiber optical waveguides.
We have analyzed the effect of the polarization of the illuminating beam on the overall pattern of the intensity distribution.
We consider the characteristic types of rays for a single-layer and two-layer fiber optical waveguide. We have obtained definitive
dependences of the beam intensity for each ray individually. We have developed a program for calculation of the scattering
pattern in fiber optical waveguides illuminated by a broad beam.
Translated from Izmeritel'naya Tekhnika, No. 3, pp. 39–42, March, 1996. 相似文献
993.
994.
Conclusions The calculations for the different levels of volume heat release showed that the integral heat fluxes at the lateral and top
surfaces are virtually independent of the scenario of convective flow. However, the maximum of the heat flux on the lateral
surface in the homogeneous case is 1.5–1.6 times higher than the maximum heat flux in the stratified case. This could result
in larger mechanical loads on the reactor vessel and therefore more stringent requirements on the cooling of the outer surface
of the reactor vessel.
Institute of Fast Reactors, Russian Academy of Sciences. Translated from Atomnaya énergiya, Vol. 76, No. 5, pp. 406–411, May,
1994. 相似文献
995.
996.
All-Union Scientific-Research Institute of Nuclear Power Plants NIIP. Translated from Atomnaya énergiya, Vol. 77, No. 5, pp.
392–402, November, 1994. 相似文献
997.
The temperature change due to the conversion of mechanical deformation to internal heat and its effect on the as-measured
stress-strain behavior of alloy 304L was investigated by means of initially isothermal (compression specimen, dies, and environment
at same temperature at initiation of test), constant strain rate, uniaxial compression of laboratory-sized cylindrical specimens.
Strain rate was varied in the range 0.01 to 1 s−1, where the thermal state of the test specimen varied from nearly isothermal to nearly adiabatic, respectively. Specimens
were deformed in the temperature range of 750 °C to 1150 °C to a strain of 1. The change in specimen temperature with applied
strain was calculatedvia finite-element analysis (FEA) from the asmeasured stress-strain data. Selected predictions were confirmed with embedded thermocouples
to verify the model employed. Temperature was found to increase monotonically with strain at a strain rate of 1 s-1, consistent with what is theoretically expected for the adiabatic case. At the 0.1 and 0.01 s-1 rates, the sample temperature initially increased, peaked, and then decreased as the sample thinned and the contact area
between the sample and the cooler dies increased. As-measured stress was corrected for softening associated with deformational
heating by interpolation between the various instantaneous stress-temperature behaviors. The resulting isothermal flow data
are compared to those predicted by a conventional method that employs an empirical estimate of the heat retention efficiency
of the test specimen, assumed dependent on strain rate but independent of strain, to reduce the increase in temperature calculated
for the adiabatic case. Differences between the calculated isothermal stress-strain data from the two methods are discussed.
Values for the apparent activation energy of deformation and the strain to the peak in the flow curve, which is associated
with the onset of dynamic recrystallization, determined from isothermal stress-strain data differed significantly from those
obtained from the as-measured compression test data.
Formerly Senior Systems Engineer with EG&G Rocky Flats, Inc., is retired. 相似文献
998.
999.
I Prigione P Facchetti E Lanino A Garaventa V Pistoia 《Canadian Metallurgical Quarterly》1993,37(1):40-46
Cultures of both isolated and conjugated explants from early gastrulae of Bufo arenarum were prepared for a study of the development of ventral mesoderm. Only combinations including components of the deep ventral marginal zone and the animal pole successfully differentiated into blood cells (erythrocytes). Histological studies indicated that, while prospective mesodermal cells constituted the only source of such cells, prospective ectodermal cells provided the necessary stimulus for this kind of differentiation. Differentiated cultures, in which the tracer of cell-lineage fluorescein dextran amine was used to label these components, confirmed the above conclusions. These findings are discussed in the context of current concepts about the formation of mesoderm. 相似文献
1000.