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991.
992.
建设工程在实施过程中会面临着许多风险,其产生的经济损失也是巨大的,究其根源是缺乏对风险的认识和有效的风险处置手段。因此,通过某工程实例,对可能出现的风险因素进行了分析,并采取了有效的风险管理措施,从而避免了经济损失。 相似文献
993.
Kyu-Hyun Han Kyong-Won Seo Dae-Hyun Hwang Soon Heung Chang 《Nuclear Engineering and Design》2006,236(2):164-178
Gas-cooled reactors have been highlighted as a promising option for next generation reactor technology. A thermal hydraulic analysis code for gas-cooled reactors has been developed with a heat transfer model of a block element, which is solved implicitly with the helium energy equation. Validation was carried out through comparison with both experimental and analytical results. A computation module for annular fuel rods has been coupled to the code for comparative analyses of an annular fuel-based block element. At normal operation, the annular fuel shows 80 °C lower peak temperature than the solid fuel for the same power in Japan's high temperature engineering test reactor (HTTR), even though the pressure drop is higher in the annular fuel. 相似文献
994.
995.
熔模石膏型混合材料性能及焙烧工艺的研究 总被引:1,自引:0,他引:1
本文研究了诸因素对石膏型混合材料性能的影响,选择出合理的、廉价的造型材料配方及焙烧工艺.试验结果表明,这类混合材料尺寸稳定性高、强度适中、耐热性好,其焙烧工艺操作简便,易于控制. 相似文献
996.
本文讨论了M序列的自相关性,并证明了:当0<|t-2^n-1|≤[n-1/2]时,|CM(t)|≤2^n-1。 相似文献
997.
998.
D. Li A. F. Yee I. -W. Chen S. -C. Chang K. Takahashi 《Journal of Materials Science》1994,29(8):2205-2215
The fracture toughness and uniaxial tensile yield strengths of unmodified and CTBN-rubber-modified epoxies were measured under hydrostatic pressure. The purpose of these experiments was to learn how suppressing cavitation in rubber particles affects the deformation mechanisms and the fracture toughness of rubber-modified epoxy. It was found that the cavitation of CTBN-rubber could be suppressed at a relatively low pressure (between 30 and 38 M Pa). With cavitation suppressed, the rubber particles are unable to induce massive shearyielding in the epoxy matrix, and the fracture toughness of the rubber-modified epoxy is no higher than that of the unmodified epoxy in the pressure range studied. Unmodified epoxy shows a brittle-to-ductile transition in fracture toughness test. The reason for this transition is the postponement of the cracking process by applied pressure.Work performed while on a sabbatical leave at the University of Michigan. 相似文献
999.
A new method to predict the critical heat flux (CHF) is proposed, based on the fuzzy clustering and artificial neural network. The fuzzy clustering classifies the experimental CHF data into a few data clusters (data groups) according to the data characteristics. After classification of the experimental data, the characteristics of the resulting clusters are discussed with emphasis on the distribution of the experimental conditions and physical mechanism. The CHF data in each group are trained in an artificial neural network to predict the CHF. The artificial neural network adjusts the weight so as to minimize the prediction error within the corresponding cluster. Application of the proposed method to the KAIST CHF data bank shows good prediction capability of the CHF, better than other existing methods. 相似文献
1000.
Minor Thomas R.; Dess Nancy K.; Ben-David Eli; Chang Wei-Chao 《Canadian Metallurgical Quarterly》1994,20(4):402
The present study determined whether individual differences in neophobia during an open-field pretest predict vulnerability to inescapable electric shock, as measured by 2 tests of learned helplessness in rats. Shuttle-escape latencies and saccharin finickiness increased across groups that had received increasing numbers of inescapable shocks 24 hr earlier. Dispersion in the test measure as well as the percentage of variance explained by pretest neophobia were greater when no or few shocks were delivered in the interpolated stress phase. Pretest neophobia was positively related to stress vulnerability in both tests under these conditions. Further increments in stressor severity overwhelmed even the most stress-resistant rats, thereby decreasing dispersion in the test measure and eliminating the predictive value of pretest neophobia. This pattern of outcomes was more robust for the shuttle-escape measure of helplessness. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献