Modelling temperature and humidity in storage spaces used for cultural property in Japan

From rainy season to summer in Japan, the climate is humid. Especially in these seasons, it is difficult to maintain suitable conditions of temperature and relative humidity in exhibition and storage rooms in museums. Such climate conditions and problems are common to many countries in East Asia. Analysis using computer simulation can be a powerful tool because it is cheap and allows the simulation of a range of conditions without having to make changes to buildings and environments surrounding cultural objects. In this study, a storage building in which there is no air-conditioning unit was chosen as a target. The modelling of temperature and relative humidity in storage spaces was conducted using the Thermal and Airflow Network Model Simulation Program for buildings (NETS). The effect of seismic retro-fitting on the variation of temperature was predicted using NETS and the results were evaluated by comparing with the measured values. As a result, the heat transfer was successfully calculated and the modelled temperature represents the measured values reasonably well. Computing relative humidity by taking into account the effect of porous hygroscopic materials is challenging. In order to overcome this problem, the κ-ν model was adopted. We have some improvements but the study is still ongoing.     

建环专业《热质交换原理与设备》精品课程建设探讨

为适应新时期高等教育培养目标的要求,本文从理论课教学、实验课教学及师资队伍建设等方面建设《热质交换原理与设备》精品课程,培育了一支高水平的教师队伍,培养了学生的综合能力,也为该课程能够健康持续地发展打下扎实基础,为培养高级应用型工程技术人才奠定良好的基础。     

搜索引擎评价指标体系比较研究

本文通过对搜索引擎评价指标体系相关重要文献的研究,结合目前该领域研究的重点,对一些比较有特点的评价指标进行对比分析,阐述了当前评价指标体系研究的特点,最后提出了自己对指标评价体系新的发展展望。     

企业网站搜索引擎优化策略研究

搜索引擎优化对企业推广有着重要的作用。在分析影响网站搜索引擎排名的因素的基础上,总结出有利于提高企业网站排名的搜索引擎优化策略。     

如何利用Invisible-web获取更多的网络信息资源

在浩瀚如海的网络世界里,信息资源犹如海洋生物,大大小小,无孔不入,如何能够快速而准确地找到并获取自己所需的信息,成为我们这个时代最需解决的根本问题之一。当然,利用各种搜索引擎可以查找到很多信息资源,但是也有一些信息通过搜索引擎是无法找到的,它们隐藏在这个网络世界的某个角落,因为某种原因而不为大多人所熟知,但是这些信息本身却有着很高的使用价值。美国的Sherman·C等人把这些资源命名为"看不见的网站(Invisible—web)"。"看不见的网站"里拥有信息检索人员难以置信的有价值的资源。本文阐述了"看不见的网站"的含义及价值,指出信息检索人员应该如何有效利用"看不见的网站"资源,最后提供一些查找"看不见网站"的途径与工具。     

因特网信息检索初探

人们经常在因特网中利用搜索引擎或其它方式搜索自己所需要的信息,文章介绍了主要且最常用的几种方法:文字信息检索、图片信息检索、音乐信息检索、视频信息检索和人肉搜索.     

Stirling数与Lah数之间的相关性

本文进一步讨论组合数学中Stirling数与Lah数之间的相关性,得到许多新结果.     

A Typology of Undergraduate Textbook Definitions of ‘Heat’ across Science Disciplines

The physics and chemistry education literature has grappled with an appropriate definition for the concept of heat for the past four decades. Most of the literature promotes the view that heat is ‘energy in transit’ or ‘involves the transfer of energy’ between the system and surroundings because of a difference in temperature. Given that many undergraduate students are not learning the concept of heat in physics and chemistry alone, the goal of this investigation is to explore the conceptions of heat as presented in textbooks from across the science disciplines. An analysis of the definitions of heat from physics, chemistry, the biological sciences and the earth sciences showed a significant variation in the definitions within a discipline and between the disciplines. Specifically, the physics and chemistry textbooks used ‘energy in transit’ or ‘transfer of energy’ definitions (Class I), whereas textbooks from other disciplines typically used definitions which relate heat to ‘molecular kinetic energy’ (Class II) or they used a hybrid of Class I and II definitions. Although a universal definition of heat across disciplines may not be possible (or even desirable), we suggest that discrepancies in definitions be acknowledged and clearly communicated to students.     

Modeling and multi-objective optimization of a gasoline engine using neural networks and evolutionary algorithms

In this paper, a multi-objective particle swarm optimization （MOPSO） algorithm and a nondominated sorting genetic algorithm II （NSGA-II） are used to optimize the operating parameters of a 1.6 L, spark ignition （SI） gasoline engine. The aim of this optimization is to reduce engine emissions in terms of carbon monoxide （CO）, hydrocarbons （HC）, and nitrogen oxides （NOx）, which are the causes of diverse environmental problems such as air pollution and global warming. Stationary engine tests were performed for data generation, covering 60 operating conditions. Artificial neural networks （ANNs） were used to predict exhaust emissions, whose inputs were from six engine operating parameters, and the outputs were three resulting exhaust emissions. The outputs of ANNs were used to evaluate objective functions within the optimization algorithms： NSGA-II and MOPSO. Then a decision-making process was conducted, using a fuzzy method to select a Pareto solution with which the best emission reductions can be achieved. The NSGA-II algorithm achieved reductions of at least 9.84%, 82.44%, and 13.78% for CO, HC, and NOx, respectively. With a MOPSO algorithm the reached reductions were at least 13.68%, 83.80%, and 7.67% for CO, HC, and NOx, respectively.     

应用吸收式热泵提高热电厂经济效能研究

为了提高热电厂供热经济效能,以热泵原理的研究为基础,利用Thermoflow专业软件模拟一台亚临界600MW一次中间再热供热机组,直接以汽轮机0.4MPa,250℃抽汽作为热源向城市热网供热,供热量为440GJ/h。在此基础上对选用吸收式热泵技术回收低温余热供热的新系统进行模拟,以汽轮机0.4MPa,250℃抽汽作为吸收式热泵的驱动蒸汽,提高循环冷却水的品位供热。在供热量不变的情况下,模拟结果证实热电厂采用吸收式热泵的供热方法和传统直接以汽轮机抽汽为热源的供热方法相比,可以帮助电厂每年节省767966～1053453GJ的热量,节省标准煤26204～35945吨,同时减少排放温室气体CO269702～95613吨。说明吸收式热泵对于余热的回收可以产生巨大的经济效益和环境效益。