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11.
高热流密度电加热元件   总被引:1,自引:0,他引:1  
张贵勤 《核动力工程》1989,10(6):51-55,F003
本文论述了用于液态金属钠热工水力性能研究的高热流密度模拟电加热元件的结构特点、材料选择、热电偶设置及其他与棒束传热实验研究有关的问题。  相似文献   
12.
界面流法计算反应堆六角形燃料组件中子通量密度分布   总被引:1,自引:1,他引:0  
利用界面流法计算两维六角形轻水堆燃料组件中子通量密度分布。子区内中子源在空间上采用二次分布近似,还考虑了六角形组件周边水隙对组件内中子通量密度的影响。根据提出的模型,编制了TPHEX-E程序,并对一些轻水堆六角形组件问题作了计算,计算结果与蒙特卡罗方法计算结果进行了比较,符合良好。本程序可用于六角形轻水堆燃料组件计算。  相似文献   
13.
用面向对象方法建立人事信息系统   总被引:1,自引:0,他引:1  
应用先进的面向对象设计方法开发了技术中心人事信息系统,采用E-R数据库建立了数据库逻辑模型,通过VFP语言设计了友好直观的用户使用界面。实践表明,新开发的人事信息系统速度快、容量大,操作性强,对实现信息管理标准化,尤其是人力资源的动态管理和科学决策具有很强的实用性。  相似文献   
14.
指出了加热流道内含汽量传统算法中存在的问题 ,并提出了新的算法  相似文献   
15.
BACKGROUND: The first stage of the cork industrial process generates great volumes of wastewater with moderate to high organic pollutant content that must be purified using different procedures, such as filtration by membranes. RESULTS: The tangential filtration of these wastewaters was studied using two different laboratory equipments. In the first one, three ultrafiltration (UF) membranes were tested, with molecular weight cut‐off (MWCO) 100 kDa and 30 kDa, and two operating modes were used: total recycling of permeate and retentate streams, and in continuous mode, without recycling both streams. In the total recycling UF experiments, the influence of the operating variables on the permeate flux was first established. The effectiveness of the different membranes was determined by evaluating the rejection coefficients for several parameters that measure the global pollutant content of the effluent. The values found for these rejection coefficients were in the following order: ellagic acid and color > absorbance at 254 nm > tannic content > COD (chemical oxygen demand). In the continuous mode experiments, the fouling mechanism for each membrane was established by fitting the experimental data to various filtration fouling models given in the literature. The operating mode in the second equipment was batch concentration, and additional experiments were carried out with an UF membrane (2 kDa), and with a NF membrane (with MWCO in the range 150–300 Da). CONCLUSIONS: The three operating modes tested provided different rejection levels of organic matter; among them, the most effective procedure tested was batch concentration mode using a NF membrane. Copyright © 2007 Society of Chemical Industry  相似文献   
16.
Many approaches have been proposed to enhance software productivity and reliability. These approaches typically fall into three categories: the engineering approach, the formal approach and the knowledge-based approach. But the optimal gain in software productivity cannot be obtained if one relies on only one of these approaches. This paper describes the work in knowledge-based software engineering conducted by the authors for the past 10 years. The final goal of the research is to develop a paradigm for software engineering which integrates the three approaches mentioned above. A knowledge-based tool which can support the whole process of software development is provided in this paper.  相似文献   
17.
Hyperion, IKONOS, ALI, and ETM+ sensors in the study of African rainforests   总被引:4,自引:0,他引:4  
The goal of this research was to compare narrowband hyperspectral Hyperion data with broadband hyperspatial IKONOS data and advanced multispectral Advanced Land Imager (ALI) and Landsat-7 Enhanced Thematic Mapper Plus (ETM+) data through modeling and classifying complex rainforest vegetation. For this purpose, Hyperion, ALI, IKONOS, and ETM+ data were acquired for southern Cameroon, a region considered to be a representative area for tropical moist evergreen and semi-deciduous forests. Field data, collected in near-real time to coincide with satellite sensor overpass, were used to (1) quantify and model the biomass of tree, shrub, and weed species; and (2) characterize forest land use/land cover (LULC) classes.The study established that even the most advanced broadband sensors (i.e., ETM+, IKONOS, and ALI) had serious limitations in modeling biomass and in classifying forest LULC classes. The broadband models explained only 13-60% of the variability in biomass across primary forests, secondary forests, and fallows. The overall accuracies were between 42% and 51% for classifying nine complex rainforest LULC classes using the broadband data of these sensors. Within individual vegetation types (e.g., primary or secondary forest), the overall accuracies increased slightly, but followed a similar trend. Among the broadband sensors, ALI sensor performed better than the IKONOS and ETM+ sensors.When compared to the three broadband sensors, Hyperion narrowband data produced (1) models that explained 36-83% more of the variability in rainforest biomass, and (2) LULC classifications with 45-52% higher overall accuracies. Twenty-three Hyperion narrowbands that were most sensitive in modeling forest biomass and in classifying forest LULC classes were identified and discussed.  相似文献   
18.
The embedding of a small but expressive language of multidimensional functional programming in a well known and widely used language of object‐oriented programming leads to the combination of two radically different programming models. In this paper, we formally define the syntax and semantics of GLU?, which can be thought of as the multidimensional core of Lucid and GLU, and we describe its implementation as a language embedded in C++. With the aid of a few examples, we argue that the marriage of the two programming models is not only compatible and natural, but also that it produces a new and interesting hybrid language. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
19.
T Okamura  M Saeki  K Hama  M Shiotsu 《低温学》2004,44(9):603-609
Critical heat fluxes (CHFs) were measured for two types of rectangular ducts containing horizontal flat plate heaters. One has the flat plate heater of 6 mm wide and 20 mm long located on the inner lower wall at 50 mm from the inlet. The other duct has two horizontal flat plates of 6 mm wide and 20 mm long on inner upper and lower walls at 50 mm from the inlet. The equation of CHF for the forced convection containing a new nondimensional-parameter m introduced in order to calculate cross-sectionally averaged liquid temperature at the center of the duct was derived based on two fluid model, ordinary convection theorem and experimental results. It was confirmed that this correlation can describe not only the author's data on the duct but also other worker's data for channels with different shapes and sizes.  相似文献   
20.
Titanium Dioxide, TiO2, is a photocatalyst with a unique characteristic. A surface coated with TiO2 exhibits an extremely high affinity for water when exposed to UV light and the contact angle decreases nearly to zero. Inversely, the contact angle increases when the surface is shielded from UV. This superhydrophilic nature gives a self-cleaning effect to the coated surface and has already been applied to some construction materials, car coatings and so on. We applied this property to the enhancement of boiling heat transfer. An experiment involving the pool boiling of pure water has been performed to make clear the effect of high wettability on heat transfer characteristics. The heat transfer surface is a vertical copper cylinder of 17 mm in diameter and the measurement has been done at saturated temperature and in a steady state. Both TiO2-coated and non-coated surfaces were used for comparison. In the case of the TiO2-coated surface, it is exposed to UV light for a few hours before experiment and it is found that the maximum heat flux (CHF) is about two times larger than that of the uncoated surface. The temperature at minimum heat flux (MHF) for the superhydrophilic surface is higher by 100 K than that for the normal one. The superhydrophilic surface can be an ideal heat transfer surface. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
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