模糊petri网理论定量分析空间信息系统传输能力

运用FPN（Fuzzy Petri Nets）原理,结合层次分析法,采取定性与定量分析相结合的方法进行评价,最终利用仿真实例对信息传输能力进行评估,着重分析误码率对传输能力的影响,对实际构建和运用信息传输网络具有一定的借鉴意义。     

Review of windcatcher technologies

Mechanical cooling systems in buildings are the main producers of carbon dioxide emissions, which have negative impacts on environment and amplify global warming, particularly in hot climate. Due to the lack of energy supply, windcatchers can be utilized as a sustainable attempt for cooling and ventilation purposes. The objective of this paper is to review and provide a comprehensive literature on windcatcher system for space cooling and ventilation. The concepts were discussed according to the relevant parameters of windcatcher, i.e. windcatcher attributes, windcatcher configurations and windcatcher technologies. The pros and cons of this green architectural feature have also been highlighted and the future research need in this realm of study is proposed.     

The Power Function,of the Exact Test for the 2 × 3 Contingency Table

In continuation of the authors' tables of significance tests (1963), the power function of this exact test for the 2 × 3 contingency table using the Freeman & Halton principle is derived and evaluated numerically in the form of contours of constant power for the cases: A = 5(5) 15, where A is the total number in each of the three groups observed according to the numbers of ‘Successes’ (= a _i ) in each. Comparisons are also made with the exact significance points of the competing X ² and (?2 log λ) tests under the null hypothesis H ₀ and also alternatives to H ₀.     

提高网络类公告信息发布效率的探讨

在集团公司不断提高客户服务满意度的要求下,提高投诉处理的及时率,提高投诉处理的效率,减少每万用户投诉比成为越来越紧迫的任务。在完成这个任务的过程中,有一个关键的步骤就是如何提高公告信息发布的效率。这个网络类公告信息包括工程信息和故障信息。发布是指在EOMS上发布并在BOSS系统上呈现给客服人员查询使用。这个效率包括公告信息的及时率、准确率和有效率。     

Development of a flowsheet for iodine–sulfur thermo-chemical cycle based on optimized Bunsen reaction

Based on the Bunsen reaction process whose operating conditions are optimized to yield an over-azeotropic HI liquid solution, we devised a new flowsheet of iodine–sulfur thermo-chemical cycle. A highly enriched hydrogen-iodide gas can be generated through a series of processes of liquid–liquid separation of product mixture from Bunsen reaction and flash of over-azeotropic HI solution. Operating temperature and pressure for HI enrichment need not to be increased as high as those for existing flowsheets; as a result, the operating conditions become less corrosive. Chance of pipe clogging due to iodine solidification is low because there is no process where iodine is concentrated that high. Enrichment of HI through spontaneous liquid–liquid separation and simple flash processes avoiding complicated separate process is considered to be an additional benefit. Analysis of overall and component material balances showed that excess amount of feed to each process to get a desired output depends on the efficiency of flash and decomposition processes. Compared to previous ones, the proposed flowsheet requires more recirculation flows throughout the whole cycle mainly because only a portion of HI content exceeding the azeotrope is allowed to evaporate in the flash without employing a separate HI enrichment process. Thermal efficiency of the proposed flowsheet was evaluated, together with a series of parametric analyses for the sensitivity to key operating parameters and component performances. It was observed that the thermal efficiency can be raised above 60% at optimal condition.     

Burn threshold prediction for High Efficiency Deep Grinding

Burn threshold diagrams are useful for the prediction of thermally induced grinding damage and were originally developed to describe the conventional shallow cut grinding regime. With the development of new high stock removal grinding processes such as High Efficiency Deep Grinding (HEDG), the prevention of thermal damage to the workpiece is of particular concern. The principle of HEDG is based around the change in thermal characteristics of the grinding process at high Peclet numbers, whereby less heat is partitioned to the workpiece. Conventional burn threshold diagrams are valid for Peclet numbers below 50, well below the values expected in HEDG. This study presents a modified approach to the construction of burn threshold diagrams which takes account of the change in thermal partitioning with Peclet number. The approach has been validated through grinding trials over a range of specific material removal rates.     

A review on solar-hydrogen/fuel cell hybrid energy systems for stationary applications

There are several methods for producing hydrogen from solar energy. Currently, the most widely used solar hydrogen production method is to obtain hydrogen by electrolyzing the water at low temperature. In this study, solar hydrogen production methods, and their current status, are assessed. Solar-hydrogen/fuel cell hybrid energy systems for stationary applications, up to the present day are also discussed, and preliminary energy and exergy efficiency analyses are performed for a photovoltaic-hydrogen/fuel cell hybrid energy system in Denizli, Turkey. Three different energy demand paths – from photovoltaic panels to the consumer – are considered. Minimum and maximum overall energy and exergy efficiencies of the system are calculated based on these paths. It is found that the overall energy efficiency values of the system vary between 0.88% and 9.7%, while minimum and maximum overall exergy efficiency values of the system are between 0.77% and 9.3% as a result of selecting various energy paths. More importantly, the hydrogen path appears to be the least efficient one due to the addition of the electrolyzer, the fuel cells and the second inverter for hydrogen production and utilization.     

Écart entre les charges permanentes réelles et celles du projet

Les marges de sécurité des projets de construction s appuient de plus en plus sur la probabilité théorique (calculée) de ruine, mais si les marges de sécurité doivent être réalistes, il est nécessaire que nous connaissions la dispersion, ainsi que la valeur moyenne de la charge d'une construction. Le Hungarian Institute for quality control of building a étudié l'écart entre les charges permanentes de diverses constructions et matériaux et celles prises en compte dans les projets. Le compte rendu original est résumé ici par G. R. Mitchell, selon une demande de la Commission W 23 du CIB.     

Enhancing the performance of solar cells via luminescent down-shifting of the incident spectrum: A review

The application of a luminescent down-shifting (LDS) layer has been proposed as a method for improving the poor spectral response (SR) of solar cells to short-wavelength light. The LDS layer absorbs photons, typically in the 300-500 nm range, and re-emits them at a longer wavelength where the photovoltaic (PV) device exhibits a significantly better response. This paper reviews the progress in this area over the last three decades, starting from early experiments that yielded promising results but being limited by the luminescent materials available at the time, to modern materials that exhibit higher luminescent quantum efficiencies and better photostability. The candidate materials are considered and their potential is reviewed for a wide range of PV technologies. A particular opportunity is the ability to use the existing polymer encapsulation layer of certain PV technologies as a LDS layer as well.     

一种提高变频器网络通讯效率的接口适配器

设计了一种提高变频器网络通讯效率的接口适配器.详细介绍该接口适配器的软硬件设计和工作原理.实验结果表明,这种适配器有效地提高了变频器网络通讯效率,具有很好的实用性.