Socioeconomic status and the occurrence of non-fatal child pedestrian injury: Results from a cross-sectional survey

This study is to examine the contribution of socioeconomic status (SES) to the risk of nonfatal pedestrian injury among children. The sample was obtained from two urban cities of China using multi-staged randomized sampling. Information was collected by respondents’ reporting using self-administrative way in the classroom under the guidance of interviewers. A logistic regression analysis was applied to examine the associations between SES and nonfatal children pedestrian injury. The results showed that boys and children aged 10 had significantly increased odds of suffering nonfatal pedestrian injury. Migrant children were at higher risk of being injured. Students whose mothers’ educational levels were either less than secondary school or postgraduate were more likely to sustain injury. Children who were from wealthier families or poorer families easily suffered from injury compared to children from middle families. Children living with grandparents, or siblings, or a single father, or a single mother were all at increased risk of injury. The possible causes or pathways of these SESs’ impacts on pedestrian injury were explored in discussion. This study suggests that SESs are important determinants of nonfatal pedestrian injury among children in China.     

区域地震应急能力优先建设矩阵构建方法的初步研究——以四川省为例

借鉴新一代的时间管理理论——"时间管理优先矩阵",提出并分析了区域地震应急能力优先建设矩阵的概念。分别以区域绝对和相对地震应急能力作为优先建设矩阵中"紧迫与否"和"重要与否"的定量化评价指标,构建了区域地震应急能力优先建设矩阵,划分了能力建设的四种类型,即需重点建设且紧迫性较强的区域类型(第Ⅰ类)、需重点建设但紧迫性较弱的区域类型(第Ⅱ类)、次重要建设但具一定紧迫性的区域类型(第Ⅲ类)和次重要建设且紧迫性较弱的区域类型(第Ⅳ类),在区域能力建设过程中应当遵循从第Ⅰ类到第Ⅳ类建设力度由重到轻、时间由急到缓,逐步开展的原则。最后,以四川省为例,以县(市)为基本评价单元,给出了四川省未来地震应急能力建设的优先等级类型。     

The expansion process of a Stellera chamaejasme population in a degraded alpine meadow of Northwest China

Environmental Science and Pollution Research - The expansion of poisonous plants can change vegetation community structures and affect grassland ecosystem service values. Stellera chamaejasme is...     

湿热处理餐厨废弃物不饱和脂肪酸

为了研究湿热水解技术对餐厨废弃物中脂类物质的影响,促进餐厨废弃物的资源化处理利用,通过实验研究,分析了餐厨废弃物固相中油酸、亚油酸、α-亚麻酸和花生四烯酸4种不饱和脂肪酸在90～140℃湿热条件下处理随时间的变化规律。结果表明：实验所取餐厨废弃物经湿热处理后固相中油酸和亚油酸的含量相对较高,约为30％,花生四烯酸的含量较低,约为0．3％,随着加热时间延长,亚油酸在湿热环境下发生化学分解,其含量不断降低,而花生四烯酸的含量显著增加。当加热温度为100～120℃,加热时间为30-60min时,餐厨废弃物脂类含量比较稳定,作为适宜的湿热处理条件。值得注意的是,湿热处理后的餐厨废弃物中花生四烯酸的含量只约为0．3％,不能满足饲料标准中2％的要求。     

Identification and characterization of the atmospheric emission of polychlorinated naphthalenes from electric arc furnaces

Electric arc furnaces (EAF) are well recognized as significant sources of dioxins. EAFs have also been speculated to be sources of polychlorinated naphthalenes (PCNs) due to the close correlation between dioxin and PCN formation. However, assessment on PCN emissions from EAFs has not been carried out. The primary aim of this preliminary study is to identify and characterize the atmospheric emission of PCNs from EAFs. In this preliminary study, stack gas samples from two typical EAFs with different scales (EAF-1, 160?t batch(-1); and EAF-2, 60?t batch(-1)) were collected by automatic isokinetic sampling technique, and PCN congeners in samples were analyzed by isotope dilution high-resolution gas chromatography combined with high-resolution mass spectrometry method. Emission concentrations of PCNs were 458 and 1,099?ng?m(-3) for EAF-1 and EAF-2, respectively. The emission factors of PCNs to air were 21.6 and 30.1?ng toxic equivalent t(-1) for EAF-1 and EAF-2, respectively, which suggested that EAF is an important source of PCN release. With regard to the characteristics of PCNs from EAFs, lower chlorinated homologues were dominant. The PCN congeners comprised of CN27/30, CN52/60, CN66/67, and CN73 were the most abundant congeners for tetra-, penta-, hexa-, and hepta-chlorinated homologues, respectively. EAFs were identified to be an important PCN source, and the obtained data are useful for developing a PCN inventory. The congener profiles of PCNs presented here might provide helpful information for identifying the specific sources of PCNs emitted from EAFs.     

水解+加压MBR处理淀粉废水研究

对水解+加压MBR处理中等难降解淀粉废水进行了探索性研究。试验结果表明增加水解酸化预处理后加压MBR处理效果有明显增加,不同操作压力下,膜过滤出水COD仅为无水解酸化预处理时的1/2。在操作压力为045MPa,进水COD10430mg/L,容积负荷522kgCOD/m3·d时,膜滤出水COD仅为202mg/L,COD去除率高达9981%。     

Laboratory-scale experiments applied to the design of a two-stage submerged combustion evaporation system

To simulate a submerged combustion evaporation (SCE) process under laboratory conditions, this study conducted three kinds of indirect-heating evaporation experiments, including normal evaporation, vacuum evaporation, and gas-carrying evaporation experiments on mature municipal solid waste (MSW) landfill leachate. The results showed that the organic concentrations in terms of COD in condensates were always very high at the beginning, then decreased rapidly, and stabilized at a low level, which suggests that only the forepart of vapors need to be safely treated to control the discharge of organic pollutants. This study applied the process in developing a two-stage SCE system, which has been implemented for the treatment of biologically pretreated and concentrated leachate from Membrane Bioreactor (MBR) and Reverse Osmosis (RO) combined process in the Beishenshu MSW Landfill, Beijing, China. The result shows that the two-stage SCE system can successfully further concentrate refractory organic matter in concentrated leachate and remove volatile organics from the vapor.     

中山市城区建筑物抗震能力与抗震措施研究

通过对广东省中山市城区建筑物震害预测的分析研究,明确了中山市城区当前建筑物存在的抗震薄弱环节,确定了危旧房屋集中地段的分布,给出了中山市城区建筑物抗震能力综合评价,对重要建筑物的安全程度做出了判断,最后提出了提高建筑物抗震能力的抗震措施。