Geographical analysis of commercial motor vehicle hazardous materials crashes on the Oregon state highway system

Crashes on highways frequently cause hazardous material exposure to the public and the environment. We evaluated differences in hazardous materials-related crashes vs. non-hazardous-material-related commercial motor vehicle crashes occurring from 2000 to 2006 on the Oregon state highway network. The two groups were compared for crash characteristics by χ² analysis, and spatial clustering was tested using Ripley's K-function and kernel density estimator analyses. There were 8,622 total commercial motor vehicle crashes, 232 being hazardous-materials related. Hazardous materials-related crashes were not significantly associated with different road surface conditions, weather conditions or cause of crash. Hazardous materials-related crashes were associated more frequently with late evening/early morning hours and under artificial lights or at dusk. The commercial motor vehicle drivers in hazardous materials-related crashes were less frequently at fault than ones in the non-hazardous materials-related crashes. The planar Ripley's K-function indicated non-hazardous materials-related crashes were more clustered than hazardous materials-related ones. Both cohorts clustered at the 12–14 mile range. The kernel density estimator analysis indicated hazardous materials-related clusters are small and discrete along the main highway corridors, non-Hazardous materials-related ones seemed to form elongated confluent clusters along all highways. Since there seem to be few differences between the two cohorts in characteristics of the crashes and the frequency of hazardous materials-related crashes is low compared to the total commercial vehicle crashes, future geographical studies may focus on characteristics of all commercial motor vehicle crashes.     

连铸钢坯二冷段喷嘴性能的实验研究

根据非稳态传热学原理,通过对大试样进行单侧加热,另一侧喷水的实验方法,对连铸二冷段喷嘴的热态性能进行了实验研究。根据实际生产条件,对不同喷水压力和不同喷水距离下,喷嘴传热系数关系进行了研究;实验结果表明:相同实验条件下,水喷嘴的传热系数高于气水喷嘴,而在均匀冷却方面,气水喷嘴更具有优势;无论哪一种喷嘴,随着喷水压力的增加,总体趋势传热系数都在增大,而随着喷水距离的增加,传热系数都在降低;同时,相同实验条件下,双喷嘴的冷却效果优于单喷嘴的冷却效果。     

中国地表水酸沉降临界负荷的区划

为了解中国地表水体对酸沉降的响应情况,应用基于酸度平衡的稳态法研究中国地表水酸沉降临界负荷区划.结果表明,中国地表水硫沉降临界负荷呈较明显的地带分布.其中,大兴安岭北端水体的硫沉降临界负荷最低,大部分小于2 keq·(hm²·a)^-1,东北北部部分水体和秦岭-淮河以南大部分地区水体的硫沉降临界负荷介于2～10 keq·(hm²·a)^-1之间,其余地区水体硫沉降临界负荷普遍大于10 keq·(hm²·a)^-1.地表水酸度临界负荷的地区分布和数值大小类似于硫沉降临界负荷由于中国地表水酸度临界负荷普遍大于2 keq·(hm²·a)^-1,因此大部分地表水对酸化并不敏感,近期内不易酸化.     

京津潮白河多环芳烃及其衍生物分布

采用固相萃取-气相色谱质谱联用仪测定京津潮白河中的多环芳烃(PAHs)及其衍生物(SPAHs)的污染水平,并采用絮凝法分析水样中自由态PAHs/SPAHs和结合态PAHs/SPAHs的分布。结果表明,京津潮白河中PAHs和SPAHs总质量浓度分别为55.06～215.02 ng·L~(-1)和92.37～227.33 ng·L~(-1),上游河段PAHs和SPAHs质量浓度均低于下游河段。7种致癌PAHs占比为22%～41%,需引起重视。本研究中的SPAHs包括三类物质:氧化PAHs(OPAHs)、甲基PAHs(MPAHs)和氯代PAHs(Cl PAHs)。其中,OPAHs对SPAHs贡献最大(59%～71%),其次是Cl PAHs(22%～32%)和MPAHs(7%～14%)。京津潮白河中PAHs和SPAHs主要以自由态形式存在,总浓度可以准确估计污染物的环境风险。     

中国城市工业污染强度与经济增长耦合关系

利用幂函数模型对中国46个重点城市1993-2006年人均GDP和7项工业污染强度指标进行曲线拟合,用于描述和分析我国城市经济发展与工业污染强度的耦合状态,经模型推导提出了“效率弹性系数”,作为度量城市经济与工业污染控制协调发展程度的指标。拟合统计结果显示,中国城市工业污染强度与经济增长的关系曲线形状有明显的幂函数特征。样本城市在“曲线簇”中的位置能揭示“后发优势”以及经济-环境耦合水平优劣的信息。对样本城市效率弹性系数的统计分析证明,该系数可以作为城市经济环境管理的决策依据。     

Ontogenetic States,Effective Density,and Classification of Plant Populations

Uranov (1975) formulated a theory of the age structure of plant populations and, in particular, defined the index of ageness . On the basis of this theory, the concepts of the energy efficiency of plants in a certain ontogenetic state and the average efficiency of a population () are introduced. A new classification of populations with respect to the types of age structure is proposed which is based on both the and values and, accordingly, is named the delta–omega classification. The notion of effective population density is defined. This parameter takes into account different loads of plants in different ontogenetic states on the environment and is quantitatively equal to the product of the population density and . The proposed approaches and methods are illustrated by data on the distribution of age states in different plant species.     

Evaluation of gas release rate through holes in pipelines

A mathematical model of an accidental gas release in a long transmission pipeline is presented in terms of computational fluid mechanics. It was found that the hole model is suitable for the release of gas through a small hole, while the pipe model is suitable for the gas release through a hole corresponding to the complete breaking of the pipe. In this paper, a new model was proposed for a hole that lies between both these situations. The results of the example show that when the initial inside pressure is higher than 1.5 MPA, the mass of gas released during the sonic flow is more than 90% of the total mass of gas released. The average release rate of the total release process could be substituted by the average release rate of the sonic flow, or by 30% of the initial release rate. This approximation would become more accurate with the increase in the initial inside pressure.     

黑龙江省某市工矿企业有害因素监测结果分析

随着我国经济体制改革速度加快,各种经济类型的企业,尤其是乡镇与民营企业蓬勃发展。但是,由于一些主客观条件造成劳动安全卫生管理严重滞后于企业的经济改革,尤其是劳动卫生防护不足,职业危害严重。本次调查研究以黑龙江省某市2006—2007年的乡镇企业的基本统计数据为基础,以工矿企业为代表,开展了该市工矿企业劳动卫生现状调查,全面掌握该市市镇企业的劳动卫生现状,为行政管理部门制定职业卫生管理规划,改善乡镇企业工的劳动卫生条件,保护乡镇企业职工身心健康,促进社会的和谐稳定发展提科学的依据。     

水钠锰矿对几种重金属离子的吸附及其与锰氧化度和吸附位点的关系

矿物表面的吸附位点类型与数量决定了其对重金属离子的吸附特性,但氧化锰矿物的结构变化对表面位点,以及吸附特性的影响并不清楚.本研究通过X-射线衍射（XRD）、X-射线光电子能谱（XPS）、等温吸附等技术和方法对比分析了不同锰氧化度（AOS）酸性水钠锰矿对Pb2＋、Cu2＋、Zn2＋、Cd2＋的吸附特点,并探讨了水钠锰矿锰...     

煤矿塌陷湿地水体富营养化评价

以徐州某矿塌陷湿地为研究对象,通过对该矿塌陷湿地水体水质监测数据的分析,采用综合营养状态指数法（TLI）对该塌陷湿地水体的富营养化水平进行了评价。研究结果表明：①该矿塌陷湿地水体水质总体优于GB3838-2002Ⅳ类标准,TN和TP的平均含量分别为0.31 mg/L和0.024 mg/L,可达到Ⅱ类标准;②整个塌陷湿地水体的综合营养状态指数TLI为47.46,处于中营养状态,有向富营养化状态变化的趋势;③在水质监测数据的基础上,分析了水体营养状态变化的原因,并提出了针对该矿塌陷湿地水体的富营养化控制措施和建议。