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11.
Small and Medium Reactors (SMRs) are attractive in developing countries because of their unique features such as: better suitability for smaller electric grids, lower investment cost, smaller components and equipment to facilitate modularization, etc. Furthermore, other factors induced by SMR implementation, such as technical transfer promotion, domestic infrastructure improvement, stabilization of energy cost, and environmental protection put SMRs into a more favorable position. From the nuclear plant suppliers, many SMR designs are available for a wide range of applications. A questionnaire study, which the IAEA conducted in 1996, confirmed that several countries are interested in SMRs and that some SMRs are already in the detailed design stage. A projection shows that the total nuclear capacity would increase in all regions that consist mainly of developing countries in the near future. For a timely and broad implementation of SMRs, information exchange and cooperation are indispensable between nuclear suppliers and buyers. The IAEA continues to play a role in encouraging and assisting development and practical application of SMRs for harmonization of energy demand and supply in developing countries.  相似文献   
12.
This paper proposes an efficient exact algorithm for the general single-machine scheduling problem where machine idle time is permitted. The algorithm is an extension of the authors’ previous algorithm for the problem without machine idle time, which is based on the SSDP (Successive Sublimation Dynamic Programming) method. We first extend our previous algorithm to the problem with machine idle time and next propose several improvements. Then, the proposed algorithm is applied to four types of single-machine scheduling problems: the total weighted earliness-tardiness problem with equal (zero) release dates, that with distinct release dates, the total weighted completion time problem with distinct release dates, and the total weighted tardiness problem with distinct release dates. Computational experiments demonstrate that our algorithm outperforms existing exact algorithms and can solve instances of the first three problems with up to 200 jobs and those of the last problem with up to 80 jobs.  相似文献   
13.
Strain-induced ordering of microdomain structures in cross-linked polystyrene-block-polybutadiene-block-polystyrene (SBS) triblock copolymers was examined by the small-angle X-ray scattering technique. To stretch the SBS samples at elevated temperature above the glass transition temperature of polystyrene, polybutadiene blocks were chemically cross-linked in the disordered state. The initial morphology was disorder-like or bicontinuous due to incompletion of microphase separation in the presence of the chemical cross-links. When the cross-linked SBS samples were mechanically stretched at 130 °C and were further annealed for 24 h under a stretched state, the random domain structures ordered gradually and lamellar-like regularity was finally attained. It was found that the ordering proceeded more for the case of the higher strain.  相似文献   
14.
Structural images of the stacking faults in β-SiC were obtained with a high-resolution electron microscope. Stacking faults initially present in β-SiC powder particles were eliminated as grain growth proceeded at elevated temperatures.  相似文献   
15.
A new manufacturing process for high performance, waterborne coatings for can coating application was developed, which includes emulsification of an epoxy resin with or without a hardener by incorporation of an acrylic resin. It is possible by this new process to emulsify a variety of resins with minimum effects of the surfactant. (acrylic resin). The effects of surfactant and neutralizer on adhesion performance were studied. It was found that the effects of the acrylic resin amount were relatively small, and that the effects of the neutralizer were significant. It was confirmed that the usage of ammonia or amines with a branched alkyl group is required to achieve balanced dry and wet adhesion.  相似文献   
16.
The phase formation and microstructure of titanium oxides and composites produced by Ar–O2 thermal plasma oxidation of titanium carbide powders were investigated in detail by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Relationships between the phase compositions and microstructures of the oxides were established by combined structural and phase analyses, in correlation with synthesis conditions and phase formation mechanisms. It is revealed that vapor condensation favored the formation of anatase, which existed as smaller particles, while liquid/solid oxidation favored the formation of rutile, which appeared as larger particles or composites. A higher oxygen input in the plasma gases (Ar + O2) enhanced the formation of anatase due to impeded oxidation and evaporation. A small amount of Ti4O7 and Ti3O5 was detected in the larger particles coexisting with rutile or TiC. These suboxides were formed as intermediates in solid oxidation of TiC or precipitated from the Ti–C–O melt during cooling. Furthermore, extensive cracks, dislocations and stresses were observed in the monolithic rutile and composites, in association with the rapid quenching in this high-temperature in-flight oxidation process.  相似文献   
17.
A pre-heating vaporization technology of coal water slurry, CWS, was developed to increase the efficiency of coal gasification with the reduction of oxygen consumption. A CWS pre-heating experimental unit having a capacity of 2.0 tons-coal/day was manufactured. After the CWS was heated to 573 K at about 10 MPa, water in CWS was continuously vaporized in a tube of which the diameter increased gradually (2–10 mm I.D.), and dry coal particles with steam were atomized and fed to a vessel. No aggregation of coal particles was observed in the atomized samples. The temperature and the pressure distributions of the fluid were calculated with empirical heat transfer and pressure drop correlations. The calculated results well corresponded to the experimental data measured in some test points. Using the calculation model, a large scale apparatus of 100 tons-coal/day was designed using KNO3 + NaNO2 + NaNO3 molten salt as a heating medium.  相似文献   
18.
在信息化建设中,信息资源的开发和利用是信息化建设的核心内容。建设法人单位基础信息库(下简称法人库),其目的就是整合、共享作为社会活动两大主体之一的法人单位的基础信息。而建设法人库既涉及技术标准,又涉及管理体制问题。为提高法人库建设的实际效果,选定切合实际的建设模式尤其重要。本文重点介绍“集中式”和“分布式”两种法人库建设模式的各自特点和适用环境。  相似文献   
19.
为了解决大规模分布式光伏并网导致的电压越限问题,提出一种含高渗透率分布式光伏配电网的网络分区与电压协调控制方法。首先根据改进的模块度函数分区算法将配电网划分为若干分区。再以光伏有功削减量、节点电压偏差和网损之和最小为目标构建各分区子优化控制模型。然后,根据区内信息采集和区间信息交互,采用同步交替方向乘子法协调求解各分区的子模型,经过多次迭代后将最优解输出,实现各分区并行控制。最后,将分区方法和电压控制策略应用于贵州省某地实际馈线系统,得到了良好的效果,在保证配电网经济运行的同时提高电压质量,减少功率倒送。  相似文献   
20.
The irregular strip-packing problem (ISP) requires a given set of non-convex polygons to be placed without overlap within a rectangular container having a fixed width and a variable length, which is to be minimized. As a core sub-problem to solve ISP, we consider an overlap minimization problem (OMP) whose objective is to place all polygons into a container with given width and length so that the total amount of overlap between polygons is made as small as possible. We propose to use directional penetration depths to measure the amount of overlap between a pair of polygons, and present an efficient algorithm to find a position with the minimum overlap for each polygon when it is translated in a specified direction. Based on this, we develop a local search algorithm for OMP that translates a polygon in horizontal and vertical directions alternately. Then we incorporate it in our algorithm for OMP, which is a variant of the guided local search algorithm. Computational results show that our algorithm improves the best-known values of some well-known benchmark instances.  相似文献   
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