成都市地铁站及车厢内挥发性有机化合物种类探究及影响因素分析

为探究成都地铁站及车厢内部挥发性有机化合物(VOCs)种类、来源及影响因素,使用恒流气体采样器和TENAX-TA 采样管,对不同路线不同人流量期间地铁车厢内、车厢通风口和站台内部（站厅层和站台层）空气进行采样,利用气相色谱质谱联用仪(GC-MS)对车厢内VOCs进行分析。结果表明：地铁站及车厢内部VOCs主要以烷烯烃类和苯系物为主,分别占污染物种类的42.59%和27.78%;高峰期时段车厢内VOCs整体质量浓度(46.47±3.2) μg·m⁻³略高于非高峰期时段(41.35±3.82) μg·m⁻³;地铁机械通风系统可以有效稀释车厢内VOCs质量浓度;站厅层VOCs质量浓度(44.99±13.84) μg·m⁻³高于站台层的质量浓度(35.05±11.28) μg·m⁻³。由此可以看出,成都地铁内VOCs污染种类受人员密集、大气环境和通风设施等综合因素影响。本研究成果可为西南地区地铁系统VOCs污染的监管和防治提供数据支撑,亦可为相关部门提高地铁内部空气质量、降低乘客健康风险决策的制定提供参考。     

苏北某电厂脱硫方案初步比选研究

根据苏北某电厂实际需求,对脱硫方案进行比选,并根据现有案例对预期效果可达性进行分析。     

A Heat Dynamic Model for Intelligent Heating of Buildings

This article presents a heat dynamic model for prediction of the indoor temperature in an office building. The model has been used in several flexible load applications, where the indoor temperature is allowed to vary around a given reference to provide power system services by shifting the heating of the building in time. This way the thermal mass of the building can be used to absorb energy from renewable energy source when available and postpone heating in periods with lack of renewable energy generation. The model is used in a model predictive controller to ensure the residential comfort over a given prediction horizon.     

南四湖水质空间分布监测分析与水环境问题解析

南四湖作为南水北调东线工程重要的输水通道和调蓄湖泊,其水质状况一直受到人们的广泛关注。根据南四湖水质空间分布监测数据,按平均综合污染指数Pj>2的标准共筛选出29个重污染测点,其中有19个处于重污染河口外混合区,说明南四湖污染物主要来自于重污染河流;南四湖2006年秋和2007年春监测的总体平均综合污染指数分别为2.12和1.98,表明南四湖污染依然相当严重,而且秋季比春季水质更差,按湖区南阳湖、微山湖岛北、小北湖的水质最差,特别是南阳湖水质四项主要指标平均超标2倍以上。南四湖两次监测CODcr、TP、TN的单项污染分摊率平均值依次为30.6%、36.0%、33.4%,表明南四湖的主要污染物是TP、TN、CODcr。因此,在调整区域内重污染企业工业结构的同时,应实行管辖区内工业和城市生活等污水的深度处理和截蓄导用,严格执行水污染物排放标准和总量控制指标。     

北京城区和郊区本底站大气污染物浓度的多时间尺度变化特征

利用北京城区海淀宝联站(HD)和上甸子本底站(SDZ)2005—2012连续8年的大气污染物(PM_(2.5)、O3、NO2、SO_2和CO)浓度观测数据进行统计分析,揭示北京城区和郊区主要污染物浓度变化特征、超标情况及其差异.主要结论如下:1连续8年北京城区、郊区PM_(2.5)浓度整体呈缓慢下降趋势,但污染水平仍较高.海淀宝联站和上甸子本底站的PM_(2.5)年均浓度从奥运前3年(2005—2007)的平均值87.1μg·m-3和53.4μg·m-3分别下降到奥运后5年(2008—2012)的平均值67.7μg·m-3和42.1μg·m-3.奥运后5年两站PM_(2.5)年均浓度变化不大,其中城区维持在66~70μg·m-3的高浓度水平.城区PM_(2.5)浓度为3级以上的超标日在四季的发生频率相当,4级和5级以上的超标日则多发生在秋、冬季;各季平均日变化趋势均为双峰双谷型,上下班交通高峰期对PM_(2.5)浓度日变化有重要影响.2城区站O3年均浓度前5年(2006—2010)逐年下降,之后浓度开始回升,而本底站O3年均浓度在此期间变化不大,近6年(2007—2012)维持在72.4~76.3μg·m-3.城、郊O3平均日变化均呈单峰型,其中上甸子站峰值出现时刻晚于城区海淀宝联站.32005—2012年北京城区其它气态污染物浓度(NO2、SO_2和CO)总体均呈缓慢下降趋势,但在2012年浓度有所反弹,城区站气态污染物在秋、冬季的平均浓度均显著高于春、夏季.     

Selecting the Best Compatible SVC Type in Power Systems for transient Stability

Considering the increased trend to use renewable energy to meet electrical energy demands, a reliable performance also should be adopted in transmitting the generated power through the stable transmission and subtransmission systems for which nowadays Flexible AC Transmission System (FACTS) controllers are used extensively. Transient stability is one of the most important issues in power system stability analysis. FACTS devices have confirmed their capabilities in various aspects in power networks. In this paper, to improve transient stability of power systems, a shunt connected FACTS devices have been introduced, i.e., Static VAR compensators (SVCs). The SVC has the most diversified branches among FACTS devices. The main aim of this work is to study and analyze the impact of eight branches of SVC on improvement of transient stability and to choose the best of them. Simulations are performed in MATLAB/SIMULINK environment.     

电站锅炉的压力管道管理和检验要求分析

电站锅炉的压力管道参数较高,存在着较大的安全风险,一旦发生事故,后果往往十分严重.电站锅炉的压力管道在按照"锅炉"或"压力管道"进行管理时,设计、制造、安装等阶段管理要求存在交叉或不清晰的情况.进行定期检验时,又有按锅炉范围内管道或工业管道(含动力管道)执行不同技术规范的情况.本文通过按"锅炉"和"压力管道"管理时执行...     

Needs of communications with general public about the potential risk of electromagnetic fields and methods for achieving this goal

In the recent years concerns whether exposure to electromagnetic fields (EMF) from base station antennae can cause adverse health effects are grown. Great attention is paid on risk of EMF exposure to people living in a close proximity of base stations. In this issue, a point of interest is the personnel mounting, adjusting and maintaining base stations. Their working tasks require stay in high EMF levels’ conditions. There are only few studies concerning this specific occupational group. The results from our previous investigation (Zaryabova and Israel 2006) show that in␣many cases on performing some specific tasks operators are overexposed according to our national legislation, and ICNIRP guidelines. Here, we present an extended study covering more base stations and more precise scenario for performed tasks and working positions. Results of exposure assessment are presented. They include energetic load calculations on the basis of Bulgarian national legislation, and the corresponding SAR values. Data are used to determine permissible time duration for each particular work operation and served as a base for limiting the exposure and proposal for protective measures for the personnel.     

ENVIRONMENTAL AUDITING: Economic Values of Recreational Power Boating Resources in Pennsylvania

/ The travel cost method was used to estimate the economic value of seven major power boating resources in Pennsylvania. A significant relationship between number of visitor trips and cost per visitor trip existed for five of the seven water bodies. The annual total value for those five resources was $396 million, which was 2.5 times greater than the total out-of-pocket expenditures of approximately $157 million visitors spent to visit them. Research results can help resource managers plan and craft programs and policies that are founded on economic values of the natural resources involved.     

Effect of calcium formate as an additive on desulfurization in power plants

SO_2 in flue gas needs to be eliminated to alleviate air pollution. As the quality of coal decreases and environmental standard requirements become more stringent, the highefficiency desulfurization of flue gas faces more and more challenges. As an economical and environmentally friendly solution, the effect of calcium formate as an additive on desulfurization efficiency in the wet flue gas desulfurization(WFGD) process was studied for the first time. Improvement of the desulfurization efficiency was achieved with limited change in p H after calcium formate was added into the reactor, and it was found to work better than other additives tested. The positive effects were further verified in a power plant, which showed that adding calcium formate could promote the dissolution of calcium carbonate, accelerate the growth of gypsum crystals and improve the efficiency of desulfurization. Thus, calcium formate was proved to be an effective additive and can potentially be used to reduce the amount of limestone slurry required, as well as the energy consumption and operating costs in industrial desulfurization.