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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Yu. M. Mosin I. A. Zakharov E. O. Lavrova M. A. Voinova 《Refractories and Industrial Ceramics》1992,33(1-2):38-43
Conclusions It is shown that in technically suitable conditions for shaping blanks by centrifugal casting, the deposition of the particles occurs with a streamline schedule, and the coarse fractions are deposited during acceleration of the rotation of the mold. The main factor influencing the density of the finely dispersed blanks is the duration of rotation, and for systems containing coarse filler, centrifugal acceleration. Regulating the dimensions (wall thickness) of the blank is possible by altering the concentration of solid phase in the slip and the degree of filling of the mold with it.Translated from Ogneupory, No. 1, pp. 22–24, January, 1992. 相似文献
992.
L. A. Kryachko V. N. Paderno O. I. Kovalenko 《Powder Metallurgy and Metal Ceramics》1992,31(6):510-518
Translated from Poroshkovaya Metallurgiya, No. 6(354), pp. 58–69, June, 1992. 相似文献
993.
John Drennan David R. Clarke Richard H. J. Hannink Thomas M. Shaw 《Journal of the American Ceramic Society》1994,77(8):2001-2008
The microstructure, average grain size, and density of Mg-PSZ sintered with SrO and SiO2 additions are found to depend on the partial pressure of oxygen in the sintering atmosphere. Over the range of 10−1 to 10° atm, both the average grain size and the density increase with oxygen partial pressure, for a constant SrO/SiO2 ratio. The partial pressure of oxygen also affects the microstructural distribution of the remnant liquid phase. At high partial pressures the liquid phase is uniformly distributed, whereas at lower oxygen pressures it is preferentially located near the surface. It is proposed that the microstructure produced by sintering is the result of a competition between liquid-phase-enhanced densification and the migration of the liquid phase to the free surface. The migration is attributed to vaporization of MgO from the liquid phase which increases with decreasing partial pressure of oxygen. 相似文献
994.
A compact method of calculation for solving a fundamental problem in structural chemistry — the problem of optimizing the geometric structure of molecular systems — is proposed. Solution of this problem will allow predicting a number of properties of polymer systems based on the existence of a structure—property correlation. It should be noted that the proposed method allows performing all calculations in analytical form. 相似文献
995.
O. V. Chudina 《Metal Science and Heat Treatment》1994,36(3):125-129
In recent years, combination methods for surface hardening of alloys have been actively developed and incorporated into industrial practice. The widespread interest in such technologies is explained by the possibility of obtaining extremely high-quality surface properties for the pieces. In this paper, we consider the technology for combination surface hardening of low-carbon steel, involving laser alloying of the surface with nitride forming elements followed by nitrïding of the entire alloyed layer. We have investigated the properties of the hardened surface layer.Moscow Highway Institute. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 3, pp. 2–5, March, 1994. 相似文献
996.
997.
Florsheim Paul; Behling Steven; South Mikle; Fowles Timothy R.; DeWitt John 《Canadian Metallurgical Quarterly》2004,1(2):126
This study adopted a systemic approach to studying intervention efforts with delinquent youth, examining the association between several youth corrections programs and adult criminal outcomes. Two studies were designed to use juvenile and adult court records to evaluate the effectiveness of treatment programs provided to delinquent youth in state custody. The results of Study 1 suggested that court-recorded delinquent charges can be used to estimate delinquency severity. The results of Study 2 presented a discouraging but not entirely unexpected illustration of the effectiveness of intervention efforts among delinquent youth. It was found that time spent in juvenile detention facilities, work programs, and group homes was associated with negative adult criminal outcomes. No links between time spent in youth corrections programs and positive outcomes were identified. Implications for future program evaluation efforts are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
998.
Yu. A. Volodin O. F. Glagoleva T. P. Klokova 《Chemistry and Technology of Fuels and Oils》2003,39(4):213-215
Preparation is one method of increasing the efficiency of crude oil feedstock refining processes. In this stage, the feedstock can be activated by regulating the balance of intermolecular interaction forces within a crude oil disperse system by different methods: external fields (electric, magnetic); mechanical; using different kinds of additives, primarily those with surface–active properties. 相似文献
999.
Determination of Boundary Shear Stress and Reynolds Shear Stress in Smooth Rectangular Channel Flows 总被引:1,自引:0,他引:1
A method for computing three-dimensional Reynolds shear stresses and boundary shear stress distribution in smooth rectangular channels is developed by applying an order of magnitude analysis to integrate the Reynolds equations. A simplified relationship between the lateral and vertical terms is hypothesized for which the Reynolds equations become solvable. This relationship has the form of a power law with an exponent of n = 1, 2, or infinity. The semiempirical equations for the boundary shear distribution and the distribution of Reynolds shear stresses are compared with measured data in open channels. The power-law exponent of 2 gave the best overall results while n=infinity gave good results near the boundary. 相似文献
1000.
Very high-order microring resonator filters for WDM applications 总被引:6,自引:0,他引:6
B.E. Little S.T. Chu P.P. Absil J.V. Hryniewicz F.G. Johnson F. Seiferth D. Gill V. Van O. King M. Trakalo 《Photonics Technology Letters, IEEE》2004,16(10):2263-2265
High-order microring resonators having from 1 to 11 coupled cavities are demonstrated. These filters exhibit low loss, flat tops, and out-of-band rejection ratios that can exceed 80 dB. They achieve performance that is suitable for commercial applications. 相似文献