地下煤火土壤典型重金属分布特征

通过采集乌鲁木齐大泉湖火区土壤样及实验室测定,研究了火区土壤理化性质与重金属Hg,As,Cu,Pb,Cr,Zn,Ni空间分布特征。结果表明:温度正常区土壤温度随采样深度增加的幅度较温度异常区小;温度正常、温度异常区土壤有机质含量随深度的增加均减少,温度正常区I,II,III,IV层土壤有机质含量大于温度异常区相应土层有机质含量;温度异常区土壤层I重金属Cu,Pb,Cr,Zn,Ni含量均小于温度正常区土壤层I相应重金属含量,II层则有增加的趋势并大于温度正常区相应土层重金属含量;温度正常区、温度异常区土壤Hg,As,Cu,Ni重金属含量随深度变化幅度及波动幅度较小,而温度异常区土壤Pb,Cr,Zn重金属含量随深度变化波动幅度较温度正常区大;火区热效应、地形、土壤及气象因子是影响土壤重金属分布的主要原因。土壤典型重金属砷形态分析表明:残留态砷含量最高,水溶态砷含量最低;水溶态砷在火区取样区域内I,II,III,IV土壤层区域富集特征与各层土壤碳酸钙富集特征趋于一致;温度正常区土壤残留态砷、铁形砷含量随深度变化的趋势与土壤碳酸钙含量随深度变化趋势一致;温度异常区残留态砷含量随深度增加波动趋势与土壤有机质含量波动趋势有较强关联性;温度正常区、温度异常区均值水溶态砷含量基本稳定,表明其与温度、土壤特性等无明显相关性。     

建筑能耗模拟典型年中气象参数权重的确定

在建筑能耗模拟用典型年的生成中,传统的Finkelstein-Schafer统计方法对气象参数赋予了固定的权重因子,但有关研究表明,由于地域间气象资源不同,气象参数权重因子的固化有待商榷。针对挑选典型年时气象参数权重因子统一与否对典型年挑选结果和建筑能耗模拟准确性的影响问题,选同一建筑热工分区中寒冷地区的代表城市北京和拉萨,分别使用FS方法和主成分法进行了典型年的挑选,并对典型公共建筑建模进行了能耗模拟分析。结果表明:FS统计方法适于表征单独气象参数的长期相似性,但存在对太阳辐射参数权重赋予过大的问题,适用于太阳能丰富地区;而主成分法适合寻求当地气象资源的本质特征,使用主成分法时对气象参数的选择尤为重要。     

医疗内窥镜影像系统的设计与实现

设计并实现了消化内镜影像系统的常用功能,并增加了病变图像的二次采集,典型病例库的维护以及“所见即所得”的报告生成方式,提高了诊断效率。并对系统进行了全面的测试,保证了系统的稳定性和功能完备性。     

上海地区建筑能耗计算用典型年气象数据的研究

以同济大学某教学楼为研究对象,对比了用EnergyPlus模拟计算得到的全年耗电量和实测耗电量,研究了用于建筑能耗动态计算的5套典型年气象数据的可靠性,得出了CTYW气象数据最接近现实情况的结论。对其中影响较大的参数如室外气温、湿度和太阳辐射量进行分析和比较,指出所用5套典型年气象数据间的差异来自观测值的缺损和统计处理模型的不完善,特别是日射模型存在一定缺陷。     

An exergy application for analysis of buildings and HVAC systems

The paper presents an extended method for exergy analysis of buildings and Heating Ventilation Air Conditioning (HVAC) systems, according to an energy demand build-up model from the building side to the energy supply side. The HVAC systems comprise a thermal energy emission and control system, a thermal distribution system, an electricity distribution system and an energy conversion system. Energy and exergy that are required by a building and a HVAC system are posed into the external part and classified by different forms of energy carriers. The external part is out of the boundary of the study. The method is illustrated with an office building equipped with low-temperature heating and high-temperature cooling systems situated in the Netherlands. Thermal exergy and thermal energy demands of the building and thermal energy and thermal exergy losses occurring in the HVAC systems are discussed. The building and the HVAC systems to be considered meet standard Dutch energy performance regulations. Nevertheless their overall exergy efficiencies are low in both cases (17.15% and 6.81% subsequently). The exergy analysis also pinpoints that the thermal energy emission and control system and the energy conversion system are the main causes of the exergy inefficiencies in the heating and cooling cases, respectively.     

雅鲁藏布江中游径流还原计算方法探析

随着西藏"一江两河"地区人类活动的不断增加,水文断面所测的径流资料,在数量和时程分配上已不能代表河流的天然状况,在利用这些资料进行水资源评价及工程设计时,必须将实测径流还原为天然径流资料。根据该地区资料条件,雅鲁藏布江径流还原采用典型区法,先率定典型区的灌溉定额,并依据历年各水文站以上地区灌溉面积统计资料,计算还原水量,按典型区灌溉制度进行年内分配。     

晶体结构预测方法与应用

物质的微观结构是深入理解其宏观物理和化学性质的基础,晶体结构预测是晶体工程领域的重要研究内容之一。近年来,随着理论方法的不断改进和完善以及计算机技术的飞速发展,根据初始物质的化学成分来理论预测物质的微观结构已成为可能。详细介绍了几种当前主流的晶体结构预测理论及其基本原理,重点论述了基于不同算法的晶体结构预测程序的工作流程及其典型应用。     

基于层次分析法和专家经验的重要电力用户典型供电模式评估

分析了重要电力用户供电模式评估流程,然后从指标自身内涵、配电网评估因素、重要用户供电模式固有特性和专家经验4个方面挖掘了重要用户供电模式评估指标,接着依据层次分析法构建了包含方案层、指标层、准则层和目标层4个层次的综合评估体系架构,最后采用9位标度法和专家经按分层分组、自下而上的方式确定各指标的权重分配。在此基础上,给出了14种典型供电模式详细评估结果,以期为工程应用提供必要的理论依据。     

A model of nitrogen efficiency in contrasting grass-based dairy systems

Nitrogen (N) efficiency is one of the key drivers of environmentally and economically sustainable agricultural production systems. An N balance model was developed, evaluated, and validated to assess N use efficiency and N surplus and to predict N losses from contrasting grass-based dairy production systems in Ireland. Data from a 5-yr study were used to evaluate and validate the model. Grass-based and high-concentrate production systems combined with 3 divergent strains of Holstein-Friesian (HF) dairy cows—high-production North American (HP), high-durability North American (HD), and New Zealand (NZ)—were evaluated. As concentrate input increased, N surplus per hectare increased and N use efficiency per hectare decreased (23 and 10%, respectively). When the N required to rear replacement animals to maintain the production system was considered, the N surplus of the HP genetic strain was greater (156 kg of N/cow) than that of the HD (140 kg of N/cow) or the NZ (128 kg of N/cow). The model estimated N leaching of 8.1 mg of NO₃-N/L, similar to that measured by others at the same site. The model creates awareness of methods and indicators available to assess the most suitable and environmentally sustainable grass based dairy production systems.     

省级电力行政交换网软交换改造方案研究

目前省级电力行政交换网大多采用程控交换设备组网,随着程控交换设备的逐步停产和电力系统业务多样化的发展需求,急需进行行政交换网升级改造工作。文章分析了软交换与IMS的商用情况,提出了近期省级电力行政交换网改造的技术体制选择建议、改造原则、建设模式、互联互通方案和下级站点典型接入方案。旨在为近期各省／市行政交换网改造提供方案参考。