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81.
针对电力市场用户群庞大,交易过程中售电套餐选择困难的问题,在Spark环境下设计了一种售电套餐推荐方法,同时也解决了售电套餐推荐过程中在大数据环境下的可扩展性及实时性问题。首先,计算出每个套餐属性的权重值,从而计算得到售电套餐综合相似度。然后,计及用户和套餐两方面提出一种售电套餐推荐方法,实现售电套餐的精准推荐。实验表明,提出的推荐方法能够明显提高推荐的准确度,并且在分布式环境下具有良好的推荐效率和可扩展性。  相似文献   
82.
Heat transfer study of nanofluids as coolant in SCWRs core has been performed at Helwan University. A thermal hydraulic code has been produced to study the effect of TiO2 nanofluid water based as a coolant with comparison with pure water as a coolant. Various volume fractions of nanoparticles TiO2 (2, 6 and 10%) were used in order to investigate its effects on reactor thermalhydraulic characteristics. Based on Parameters of a SCW Canadian Deuterium Uranium nuclear reactor (CANDU), the fuel assembly was modeled to study the effect of nanoparticles volume fraction on thermos-physical properties of basic fluid and the temperature distribution of fuel, cladding surface and coolant in axial direction. The theoretical results showed that the density, viscosity and thermal conductivity of the coolant increases with the increase of nanoparticles volume fraction, contrasting to specific heat, which decreases with the increase in nanoparticles volume fraction.  相似文献   
83.
Openness has become an important, all‐encompassing term denoting activities facilitated by sharing, using, producing, and redistributing information and communication resources within digital information systems. We compare theoretical advancements that emphasize processes and characteristics of openness with the limitations of extant approaches that have largely focused on improvements to productivity and efficiency. Based on Foucault and Bruner's ideas, this paper contributes a new critical narrative approach to understanding openness explicitly focused on structural transformation and power. The analysis focuses on the case of open development, examining 20 key studies based primarily on developing countries. The critical narrative approach unpacked the production of power/knowledge across actors, intentions, and outcomes of openness research and practice. We find that discursive formations are reliant on technocentric and normative ideals of researchers, leading to narratives of hypothetical outcomes that exclude marginalized perspectives. We propose hermeneutic composability and contesting normative narratives of openness as analytical techniques for an integrated, mutually constitutive conception of interactions between individuals, open artefacts, and open social praxis.  相似文献   
84.
When UF6 is handled in leak tight system, the amount of uranium compound formed on the surface of containers, valves, and others in UF6 handling facilities is not so significant for a short term that special attention has not been given to this problem. The present work was done to throw some more light on this problem based on the recent experiment. We discuss the possibility that the intermolecular transfer of a fluorine atom from UF6 to UF5 may participate in the formation of uranium compound. The discussion includes also the unique features contained in the experimental result, the reaction processes assumed in this problem, and the derivation of a rate equation for expressing the deposition of uranium compound. Furthermore, we propose a new method for determining nonlinear parameters included in a governing differential equation having two variables for expressing the deposition of uranium compound from experimental raw data.  相似文献   
85.
In this paper, the oxidation behaviors of DP980 advanced high strength steel (AHSS) are studied during annealing in a hydrogen atmosphere with different temperatures and heating rates. It is revealed that with the increase in holding time, the different heating rates affecting the surface oxide precipitation on the strip surface will be weakened. Mass transfer of Mn in heating, soaking, and cooling stages has been considered to illustrate the effect of heating rate on the oxide morphology of steel. And then, the Wagner model and aluminothermic reaction kinetics were performed to discuss the transition from external to internal and maximum reduction diameter of MnO oxidation.  相似文献   
86.
博物馆恒湿文物展柜的湿度控制至关重要,为实现展柜的自动恒湿功能,本文基于吸附式空气取水原理,提出了一种将环境水汽自动补充至恒湿文物展柜系统水箱的方法,并搭建了相应的小型空气取水装置,证明了该方法的可行性;同时,构建了传热传质耦合的空气取水装置数学模型,在获取环境温湿度对装置取水量的影响规律后,分析加热功率和吸附床结构对装置单位能耗取水量的影响;此外,为便于装置的后期推广应用,提出了两个基于吸附床高度和直径的量纲为1参数。结果表明:进口空气的温度对取水量影响较小,但进口空气的湿度对取水量影响较明显,取水量随着湿度增加而增加;加热功率存在最优值,单位能耗取水量随着加热功率先增大后减小;在当前几何参数组合下,两个量纲为1参数η=2、β=4时,装置的单位能耗取水量最高。  相似文献   
87.
为解决电子设备高热通量下的散热问题,采用H2O2氧化法对烧结毛细芯进行了超亲水改性,研究了毛细芯表面润湿性对吸液性能的影响。并将改性后的超亲水毛细芯应用到环路热管内,研究了倾斜角度及加热功率对超亲水毛细芯环路热管的换热特性的影响。实验结果表明:超亲水毛细芯的吸液速度增加,吸液时间较亲水毛细芯减小了3.52ms;与普通亲水毛细芯环路热管相比,在加热功率Q=200W时,超亲水毛细芯环路热管蒸发器中心温度降低了约6.0℃,在Q=20W时启动时间与温度分别降低了33s与2.5℃。同时发现超亲水毛细芯环路热管在正重力状态时的运行温度更低,热阻较小,最低热阻仅为0.084℃/W。  相似文献   
88.
Injecting CO2 into oil reservoirs can improve the oil recovery,meanwhile achieve CO2 storage.The diffusion of CO2 in oil-water systems has a substantial impact on this process.The interface significantly affects the mass transfer of CO2 between oil and water phase.In this paper,based on the determination of the CO2 diffusion coefficient in oil or water phases,the diffusion processes of CO2 from oil to water were experimentally investigated under different pressures.A numerical method was proposed to calculate the pressure drop and the diffusion coefficient in the process of CO2 diffusion from oil to water.The experimental results indicated that the CO2 diffusion coefficient in oil or water increased rapidly with pressure up to the critical pressure of CO2 and gradually slowed down thereafter.The CO2 diffusion from oil to water was much slower than that in oil or water.The diffusion coefficient of CO2 from oil to water was one magnitude lower than that in the single liquid phase of oil or water,and the effect of pressure was not significant.Based on the diffusion coefficient of CO2 in a single liquid phase and the proposed numerical method,the pressure drop and the numerical diffusion coefficient in the process of CO2 diffusion from oil to water were calculated.The relative errors between the experimental and numerical results were within 9%.Therefore,the numerical method proposed herein can be used to predict the diffusion process of CO2 from oil to water and the diffusion coefficient associated with this process.  相似文献   
89.
地下水填充的井下换热器(GFBHE)是一种不需要灌浆,利用地下水填充钻孔进行换热的地热换热器。针对GFBHE建立了瞬态三维数值模型进行模拟,并与利用普通灌浆材料进行回填的埋管换热器进行对比。数值模型通过将孔隙型岩层等效为饱和多孔介质的方法将钻孔外部的自然对流现象考虑在内。研究了包括渗透系数、地温、钻孔孔径在内的关键因素对GFBHE性能的影响。结果表明,当含水层渗透系数大于1×10-4 m/s时,GFBHE性能明显优于利用灌浆填充钻孔的地热换热器,在富水区域利用GFBHE取代后者是可行的。GFBHE的换热性能随着钻孔孔径、含水层渗透性的增大以及地温的升高而提升。  相似文献   
90.
彭宇 《能源与节能》2020,(3):191-192
电力行业是目前国家非常重视与大力发展的行业之一。近些年来,由于接地系统接地电阻不合格引起的电力系统事故逐渐增多,并且接地电阻升高的很大一部分原因是接地体腐蚀造成的,因而人们越来重视接地体的抗腐蚀保护。简要阐述了电力系统目前预防接地体腐蚀所采取的牺牲阳极的阴极保护法,并对接地体新的改造方法提出一些建议。  相似文献   
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