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In the present work, two different classes of oxide kernels were investigated: unirradiated thoria, urania and (Th,U)O2 fuel kernels and low-density Al2O3 kernels for the incorporation of minor actinides. The physical mechanism of oxide kernel failure under uniaxial compression was investigated. A new method for determining the physico-mechanical properties of kernels has been developed and the parameters PS and δ, characterising the level of stress required for destruction of the material structure and the brittleness of the investigated materials, respectively, were evaluated and discussed. It was shown that the value of PS is analogous to traditional characteristics of material such as microhardness Hv. The `quantisation' effect was revealed in the kernel crushing strength and deformation distributions. The physico-mechanical properties of ceramic kernels (average particle size, microstructure, phase state, density, PS and δ) were investigated and comparative analysis of different kernel types was performed. Additionally, the impact of annealing time on the properties of low-density Al2O3 kernels was examined. 相似文献
143.
Y. Dai H. Glasbrenner V. Boutellier R. Bruetsch X. Jia F. Groeschel 《Journal of Nuclear Materials》2004,335(2):232-238
Liquid-solid reaction under irradiation (LiSoR) experiments are aimed at understanding the effects of liquid lead-bismuth eutectic (LBE) corrosion and embrittlement under irradiation on structural materials, which is one of the key items of the materials R&D for the future accelerator-driven system (ADS). The LiSoR setup is basically a LBE loop with a test section irradiated with 72 MeV protons. The second irradiation was conducted for about 34 h and terminated after a leakage of LBE was detected. Post-irradiation examinations (PIE) are being performed on both the tube and tensile specimen in the test section. Optical microscopy, scanning electron microscopy, transmission electron microscopy and microhardness tests have been completed. The results show that a crack formed in the irradiation zone of the tube. In the material in the irradiation zones of both the tube and the tensile specimen dislocation cell structure is well developed, which indicates heavy deformation due to thermal fatigue. The crack should start at the inner surface and propagate to the outer surface. The fracture surfaces of the crack are dominated by a brittle cleavage fracture mode. However, on the surfaces of the tensile specimen, no microcracks are observed. 相似文献
144.
深亚微米MOSFET须应用玻耳兹曼传输模型。本文建立了一个基于物理假定的解析解模型,其特点是可以加入经典模型BSIMGV3,并通过模拟程序CMOSIS进行了模拟验证。 相似文献
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W.?Zhengying T.?Yiping L.?Bingheng Z.?WeiEmail author 《The International Journal of Advanced Manufacturing Technology》2003,21(9):644-648
In order to build the complex built-in labyrinth design of an emitter which is a key element in water-saving devices, rapid prototyping and manufacturing (RP&M) is used to design the emitters and to manufacture corresponding rapid tooling (RT). Detailed CAD design of the emitter, CAD process design, and the generation of RT process modelling of the emitter have been carried out using parameterised design. Prototypes have been built using RP techniques to perform the rapid verification and modification of the emitter design; rapid tooling (RT) for the emitter has been fabricated using a metal spraying process to carry out trial-production. Finally, with the fabrication ofa precision mould as the basis, emitter mould design and manufacturing have been completed. As a result, the integration of design/verification/manufacturing of a mould and its products is realised. 相似文献
147.
Enrico Fabrizi Caterina Giusti Nicola Salvati Nikos Tzavidis 《Papers in Regional Science》2014,93(3):685-701
Measures of economic well‐being are often needed for geographically small areas, as economic indicators may be distributed unevenly among the subsets of relatively small regions. We consider small area estimation of average equivalized income. Disposable household income data are usually available only for a sample of households, typically too small to provide reliable estimates for small regions. We consider a small area estimation technique that is robust to outliers, produces results consistent with design weighted estimates obtained for larger areas and yield maps with approximately no shrinkage. The proposed methodology is applied to the Local Labour Systems in Tuscany (Italy). 相似文献
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Amazon’s online service, Mechanical Turk (MTurk) has become a popular option for data collection among social scientists. Early work (Buhrmester, Kwang, & Gosling, 2011) indicated that data collection through MTurk was faster and less expensive than traditional collection methods (undergraduate human subject pool), as well as being reliable when administered at different dates. Building on their work, we sought to extend this investigation of reliability to a larger measure. For the current research we chose a 120-item measure of personality. After collecting data through MTurk, it was determined that our MTurk sample had strong test–retest reliability, indicating that they did not significantly change between administration dates. 相似文献