天然光光环境模拟软件的对比研究

合理利用天然光,不仅可以改善室内的光环境,同时也有利于照明节能。为了实现良好的光环境,设计师需要在设计阶段准确把握光环境的效果、照明系统的性能和运行情况,从而进行合理的设计。随着计算机技术的发展,光环境模拟软件因其成本低、周期短和准确性高日益受到人们的重视,并在包括设计、建造、维护和管理等各阶段的建筑全寿命周期内得到了广泛应用。本文对目前常用的天然光光环境模拟软件进行了分类和简要介绍,并选择WINDOW、Sunshine、Radiance、Ecotect、Daysim等软件进行了比较分析,以便于使用者针对不同的应用进行选择和应用。     

Cryptosporidium spp. and Giardia duodenalis in two areas of Galicia (NW Spain)

The aim of the present study was to investigate the environmental dispersal of Cryptosporidium spp. and Giardia duodenalis in two distinct areas (coastal and inland) in Galicia (NW Spain). Faecal samples were collected from healthy asymptomatic domestic (cows and sheep) and wild animals (deer and wild boars) in the selected areas. In each of the selected areas, samples of untreated water (influent) and of treated water (final effluent) were collected from each of the 12 drinking water treatments plants (DWTPs) and 12 wastewater treatment plants (WTPs) under study. Analysis of a single sample from each of the 635 (coastal) and 851 (inland) domestic and wild animals selected at random revealed that the prevalences of cryptosporidiosis and giardiosis in coastal area were 9.2% and 15.9% respectively, and in inland area, 13.7% and 26.7% respectively. In the coastal area, Cryptosporidium spp. oocysts were detected in influent and effluent samples from 2/12 (16.6%) DWTPs and 8/12 (66.6%) WTPs, while G. duodenalis cysts were detected in influent and effluent samples from 3/12 (25.0%) DWTPs and 12/12 (100%) WTPs. The concentrations were notably higher in WTPs; the mean parasite concentrations in the final treated effluent were 10 oocysts per litre and 137.8 cysts per litre for Cryptosporidium and Giardia, respectively. The mean concentration of G. duodenalis cysts per litre was significantly higher (P < 0.05) than the mean concentration of Cryptosporidium spp. oocysts per litre in both the influent and the effluent samples from all the treatment plants. In the coastal area, C. parvum, C. hominis and G. duodenalis assemblages A (I and II) and E were most repeatedly detected. In the inland area, C. parvum, C. andersoni and G. duodenalis assemblages A (I and II), B and E were most frequently identified.     

多因素作用下钢筋混凝土构件氯离子扩散系数模型

通过对钢筋混凝土氯离子侵蚀机理的分析,在Fick第二扩散定律基础上,建立了综合考虑水灰比、湿度、时间、温度、混凝土材料对氯离子结合作用等多因素作用下的氯离子侵蚀模型,并给出了考虑边界条件的侵蚀模型数学解.通过对长期现场暴露试验数据分析,验证了该侵蚀模型的有效性和可靠性.与传统的Fick第二扩散定律模型对比并分析得:该模...     

某影城性能化消防设计中火灾场景分析与确定

指出建筑火灾性能化评估中火灾场景设定的有关要素,并指出应根据建筑火灾特点及火灾危险性进行分析,依据火灾发生与发展的基本要素以及影响火灾发展过程的各种消防措施和环境条件设定火灾场景。以某影城实际设计为例,通过不同的火灾场景设置,分析其达到安全疏散性能的要求。     

A novel approach for building occupancy simulation

Building occupancy is an important basic factor in building energy simulation but it is hard to represent due to its temporal and spatial stochastic nature. This paper presents a novel approach for building occupancy simulation based on the Markov chain. In this study, occupancy is handled as the straightforward result of occupant movement processes which occur among the spaces inside and outside a building. By using the Markov chain method to simulate this stochastic movement process, the model can generate the location for each occupant and the zone-level occupancy for the whole building. There is no explicit or implicit constraint to the number of occupants and the number of zones in the model while maintaining a simple and clear set of input parameters. From the case study of an office building, it can be seen that the model can produce realistic occupancy variations in the office building for a typical workday with key statistical properties of occupancy such as the time of morning arrival and night departure, lunch time, periods of intermediate walking-around, etc. Due to simplicity, accuracy and unrestraint, this model is sufficient and practical to simulate occupancy for building energy simulations and stochastic analysis of building heating, ventilation, and air conditioning (HVAC) systems.     

一种基于STTC变形码的MIMO跨层安全研究方案

用于高速无线通信的空时网格码,能够达到频谱利用率、分集增益与编码复杂度之间的最佳折中,是一种最佳空时码。文中提出在STTC系统中设计一种STTC变形码并将其与上层密码技术结合,充分利用信道的有噪特性,可以实现增强的无线通讯加密方式,防止信息泄露。     

管道清管器电磁跟踪定位系统接收机的设计与实现

介绍了清管器电磁跟踪定位的基本原理。提出了清管器电磁跟踪定位系统接收机的总体方案。研制了低噪声、窄通频带、高精度数据采集电路,实现了微弱磁信号的准确检测。实测表明,所设计的清管器电磁跟踪定位系统接收机,有效跟踪范围可达10米,可以满足油气管道工程实际需求。     

再生粗骨料附着砂浆含量对再生混凝土抗冻耐久性的影响

选取五种不同附着砂浆含量的商用再生粗骨料在全取代天然粗骨料条件下制备C40再生混凝土,探讨了30%极限拉应力水平下,再生粗骨料附着砂浆含量对再生混凝土抗冻耐久性的影响规律,通过数学拟合确定了基于相对动弹性模量和抗冻耐久性指数要求的砂浆界限含量。结果表明:冻融循环后,再生混凝土抗压强度损失率与附着砂浆含量存在较强线性关系;再生混凝土质量损失率、相对动弹性模量、抗冻耐久性指数均与再生粗骨料附着砂浆含量呈二次函数关系;以冻融循环300次后再生混凝土相对动弹性模量降至60%为限值,获得对应的砂浆界限含量为49.52%(质量分数);以不同设计使用年限及不同冻融工况所规定的抗冻耐久性指数作为界定条件,得到了再生混凝土在拉应力条件下满足相应抗冻耐久性指数的砂浆界限含量。最后,通过搜集文献数据验证了本研究结果的合理性。