大连市区普通居民的汞暴露风险研究

为了解沿海地区居民的汞暴露情况及其膳食汞的主要来源,对大连市区普通居民的膳食消费情况及其发汞浓度进行了调查与分析。普通居民的膳食消费情况采用调查问卷的形式进行,调查问卷的内容包括水产品消费情况、年龄、性别、身高、体重等,填写调查问卷的志愿者们同时自愿提供头发样品。膳食样品,如水产品、谷物、蔬菜等常见品种在大连市区的市场采用随机采购的方式获得。头发和膳食样品中的汞含量采用原子荧光光谱法测定,测定结果为:水产品中总汞含量为15.32(1.89~86.40)μg·kg-1,其中甲基汞含量为8.05(1.79~40.33)μg·kg-1;谷物和蔬菜总汞含量分别为2.04(0.05~11.95)μg·kg-1和0.96(0.05~2.74)μg·kg-1;头发样品中总汞浓度为(0.46±0.55)μg·g-1,其中甲基汞浓度为(0.28±0.19)μg·g-1。通过估算得知,大连市普通居民日平均的汞摄入量为0.043μg·(kg·d)-1,其中来自水产品的摄入量占膳食摄入的63.6%。居民发汞浓度与年龄、水产品食用量呈正相关,与身高、体重没有显著的相关性;与美国国家环境保护局规定的人体发汞风险参考剂量1μg·g-1相对照,此次调查人群中约有4.6%的居民发汞浓度超出该标准限值,这表明大连市区普通居民可能面临汞暴露的潜在风险。该研究结果将为我国普通居民的汞暴露评估和风险控制提供重要参考数据。     

Changes in glucose uptake rate and in the energy status of PC-12 cells acutely exposed to hexavalent chromium,an established human carcinogen

In the 1920s, Otto Warburg reported a striking metabolic shift in solid tumors: contrary to their normal counter parts, which exhibited a nearly pure respiratory metabolism, where cancer cells relied strongly on lactic fermentation for energy production, even in the presence of ample oxygen. This metabolic shift, later named the Warburg effect, is now viewed as a nearly universal cancer phenotype. To investigate whether it is operating in hexavalent chromium (Cr(VI))-induced carcinogenesis, PC-12 cells were exposed to low Cr(VI) concentrations and effects determined on the rates of glucose uptake, lactate production and oxygen consumption, critical indicators of the type of energy metabolism adopted by the cells. Further, the influence on the cells’ energy charge, an important parameter in the evaluation of the cellular physiological state was assessed. In the presence of ample oxygen, concentration-dependent, statistically significant decreases in the energy charge were detected, which were accompanied by an increased glucose uptake rate. This enhanced uptake may constitute the first step in a compensatory mechanism aimed at counteracting the decrease in energy charge. Although these changes may be too small to exert an impact in the cellular functions, they may provide insight into the initial steps of Cr(VI)-induced carcinogenesis.     

2,4-D二甲胺盐对莲草直胸跳甲生存和繁殖的影响

为探究除草剂在防治喜旱莲子草(Alternanthera philoxeroides)的过程中对其天敌昆虫的影响,采用不同浓度的2,4-D二甲胺盐浸叶处理的喜旱莲子草饲喂莲草直胸跳甲,连续饲喂7d后,考察了莲草直胸跳甲的繁殖、存活和发育情况。结果表明,2,4-D二甲胺盐可显著降低莲草直胸跳甲成虫的取食量,且抑制作用随药剂浓度升高和取食时间延长而显著增强;较高浓度(1.72～3.44g·L~(-1))的2,4-D二甲胺盐还会导致莲草直胸跳甲雌成虫存活率和产卵量的明显降低,卵孵化率、幼虫存活率和蛹羽化率也显著降低。可见,高浓度(1.72～3.44g·L~(-1))的2,4-D二甲胺盐对莲草直胸跳甲的生长发育和繁殖有显著不利影响,在防治喜旱莲子草时,应将2,4-D二甲胺盐的施用浓度控制在0.22～0.86g·L~(-1)内。     

年产120万t水泥粉磨生产线节能降耗技术改造

针对原有高能耗、低产量的立窑水泥熟料生产线进行节能降耗改造,关闭立窑熟料生产工序,改生料粉磨工序为矿渣、炉渣粉磨工序,生产出不同强度规格的水泥,每年可消耗炉渣、矿渣、煤矸石等废渣29万t以上。另引进干法旋窑水泥熟料,采用2套并列的联合水泥粉磨系统,2套八嘴回转式包装机及装车系统建设成一条年产120万t水泥粉磨生产线,使水泥粉磨综合电耗≤32(kW.h)/t,年节水量达7.2万m3,达到节能降耗、优质多产的目的。     

重大毒气泄漏事故应急预警通知接收端优化与实现

从毒气泄漏事故预防和应急处置的国内外现状分析出发,指出了目前我国预警通知方法的不足及发展趋势。论述了毒气泄漏事故中安全疏散的时间构成以及预警通知接收端低功耗模式的种类,从提高预警通知系统响应时间的角度分析了不同的低功耗方案的优劣,并给出了实现方法和适用的条件,不仅实现了不同使用条件下的最佳低功耗模式,还保证了系统有较好的实时响应速度。响应时间的优化有利于提高系统报警通知的效能,在保证较好响应时间的前提下应用低功耗模式则有利于降低成本,同时提高受灾群众安装该预警系统的积极性性,对于报警器在不同地区的推广具有指导意义,从而为对系统的优化与改进提供依据。     

滨海新区能源消费驱动因素完全分解研究

运用完全分解模型详细研究了2000-2007年间滨海新区能源消费总量变化的过程。结果表明,2000-2007年期间,经济规模扩张因素所产生的增长效应对滨海新区能源消费总量的持续增长起主导作用。与此同时,产业结构的变动对能源消费的减量作用为负面的,技术进步因素产生的能源强度效应则是推动滨海新区能源消费减量的主要因素。笔者认为,推动产业结构的跨越式演进以及在未来城市规划中增加能源消费总量约束性的发展指标是滨海新区实现能源消费总量降低的重要途径和手段。     

武汉城市圈节能建筑的处理方法及利用

从武汉城市图建筑节能的重要性及武汉市建筑节能的现状入手,指出为达到建筑节能50％的标准,武汉节能建筑处理方法应从建筑设计、建筑施工、节能技术开发应用及建筑节能管理等多方面下功夫．图8,参7．     

江苏和吉林农村家庭能源消费差异及影响因素分析

通过对江苏省和吉林省农村能源消费的实地调查,分析了农村家庭能源消费的区域差异.结果表明,由于冬季取暖需求,吉林省农村人均总能源消费量高于江苏;在生物质能源方面,江苏使用秸秆居多,而森林资源丰富的吉林以秸秆和薪柴并重;在商品能源消费方面,江苏人均消费电力、成品油、液化气多于吉林,而煤炭消耗少于吉林;在新型可再生能源--沼气消费方面,江苏的推广效果好于吉林.运用经济计量模型分析了农村家庭能源消费的影响因素,结果表明:人均纯收入、人均耕地面积、人均耐用家电价值、人均摩托车及生产性固定资产价值、地区等因素是影响农村家庭人均能源消费量的重要因素;同时,政府的资金技术支持、人均纯收入、人均生猪养殖数量、农户位于粮食主产区或林区等因素对农户选择使用沼气有重要影响.     

基于IKONOS影像的城市住宅区中水回用空间分布估算

中水回用是解决城市水资源短缺和水环境污染问题的有效途径。开展分散式中水可行性研究,需要考虑中水原水与回用需求的数量、空间分布及平衡关系。论文以南京市住宅区为例,探索了基于IKONOS高分辨率遥感影像分类,估算中水回用空间分布的方法。通过引入单位面积用水定额,将遥感和GIS 分析得到的用地信息与中水原水产量和回用需求关联起来,计算了研究区域中27 个地块的中水原水产量和回用需求量,并分析了两者在空间上的水量平衡关系。结果表明,研究区域存在较大的中水原水供给潜力3.52 L/（m²·d）和较大的利用需求5.37 L/（m²·d）。住宅小区的单位面积原水产量与其建筑容积率成正比;以中高层住宅区为主的地区,中水原水产量能够基本满足本地区的中水回用需求。因此,在这些地区建立分散式污水处理系统,可减少废污水排放,节约自来水取用量,提高水资源利用率。     

Characteristic and correlation analysis of influent and energy consumption of wastewater treatment plants in Taihu Basin

Poor biodegradability and insufficient carbon source are discovered from influent. Influent indices presented positively normal distribution or skewed distribution. Average energy consumption of WWTPs in Taihu Basin was as high as 0.458 kWh/m³. Energy consumption increases with the increase in influent volume and COD reduction. The total energy consumption decreases with the NH₃-N reduction. The water quality and energy consumption of wastewater treatment plants (WWTPs) in Taihu Basin were evaluated on the basis of the operation data from 204 municipal WWTPs in the basin by using various statistical methods. The influent ammonia nitrogen (NH₃-N) and total nitrogen (TN) of WWTPs in Taihu Basin showed normal distribution, whereas chemical oxygen demand (COD), biochemical oxygen demand (BOD₅), suspended solid (SS), and total phosphorus (TP) showed positively skewed distribution. The influent BOD₅/COD was 0.4%–0.6%, only 39.2% SS/BOD₅ exceeded the standard by 36.3%, the average BOD₅/TN was 3.82, and the probability of influent BOD₅/TP>20 was 82.8%. The average energy consumption of WWTPs in Taihu Basin in 2017 was 0.458 kWh/m³. The specific energy consumption of WWTPs with a daily treatment capacity of more than 5 × 10⁴ m³ in Taihu Basin was stable at 0.33 kWh/m³. A power function relationship was observed between the reduction in COD and NH₃-N and the specific energy consumption of pollutant reduction, and the higher the pollutant reduction is, the lower the specific energy consumption of pollutant reduction presents. In addition, a linear relationship existed between the energy consumption of WWTPs and the specific energy consumption of influent volume and pollutant reduction. Therefore, upgrading and operation with less energy consumption of WWTPs is imperative and the suggestions for Taihu WWTPs based on stringent discharge standard are proposed in detail.