基于有序Logistic回归的水库移民住房感知实证研究

针对水利工程移民的住房感知问题和住房感知等级为定序变量的特点,基于有序logistic回归分析理论,构建移民住房感知的有序logistic回归模型,并针对浯溪口水利枢纽工程移民进行实证研究。主要结论如下:1施肥种类、最高教育水平和家庭年收入对移民住房感知存在显著正向作用,水源种类对移民住房感知存在显著负向作用。2施肥种类要素分析表明,当地移民生活对农业生产依赖性较高,且移民对区域交通状态改变预期是导致其住房感知差异化的主要因素。3最高教育水平要素分析表明,教育程度越高,移民住房感知越高。4水源要素分析表明,移民对水源的获取难度和成本的预期越差,其住房感知越差。5家庭年收入要素分析表明,家庭年收入越高,移民对未来的预期越好,其住房感知越高,经济发展是解决移民问题的基础。     

AA-HPA-AMPS阻垢剂最佳合成条件研究

通过溶液聚合方法,以丙烯酸、丙烯酸羟丙酯、2-丙烯酰胺-2-甲基丙磺酸为单体,以过硫酸铵为引发剂,合成AA-HPA-AMPS聚合物。固定聚合物浓度为4mg/L,分别考查反应时间、反应温度(X1)、引发剂用量(X2)、单体配比(X3)对聚合物阻CaCO3垢性能的影响,并设计了正交实验,得出聚合物在90℃、引发剂用量为13.5%、M(AA)∶M(HPA)为7∶3时,阻CaCO3垢率最高为80.9%。为探究此聚合物是否有更高的阻垢性能,应用多元回归分析对正交实验结果进行分析及验证,聚合物阻CaCO3垢效率y与各影响因素x之间基本满足y=-146.825+16.25x2,最佳聚合条件为X2=14.5,y为90.20%。     

基于结构方程模型的安全文化影响因子分析

为进一步研究安全文化,采用结构方程模型(SEM)对安全文化的关键要素、构成因子以及因子间的因果关系进行研究。利用SPSS对山东4个国有煤矿355名员工安全文化定量测量数据进行分析。采用主成分抽取方法对安全文化关键要素进行因子分析,抽取特征根大于1的5个因子,解释变量的累积百分比为69.35%。同时运用结构方程模型软件(AMOS)构建安全文化结构模型以及安全文化因子间因果关系结构模型,证实领导责任因子对安全理念、安全认知和员工参与有直接正面影响。其中,对安全认知的影响最为显著(其路径系数为0.76);领导责任因子对安全业绩具有间接正面影响;安全理念、安全认知和员工参与对安全业绩具有直接正面影响。     

基于计划行为理论的矿工故意违章行为意向研究

为进一步解释和预测矿工故意违章行为意向,寻求可能的干预对策,以计划行为理论(TPB)为基本的理论构架,加入过去行为和示范性规范2个变量,构建了矿工故意违章行为意向假设模型。采取分层随机抽样方法,对412名矿工进行问卷调查,并借助结构方程建模技术对提出的假设模型进行了验证。研究表明:违章态度、知觉行为控制、示范性规范均对故意违章行为意向有显著的正向影响;主观规范对违章行为意向没有显著的直接影响;主观规范和过去行为通过违章态度间接正向影响违章行为意向。违章态度和示范性规范对故意违章行为意向的整体影响系数比较高,转变违章态度以及发挥群体其他成员遵章行为的示范性是降低故意违章行为意向的重要途径。     

Understanding the Factors That Influence Headwater Stream Flows in Response to Storm Events1

Stanfield, Les W. and Don A. Jackson, 2011. Understanding the Factors That Influence Headwater Stream Flows in Response to Storm Events. Journal of the American Water Resources Association (JAWRA) 1‐22. DOI: 10.1111/j.1752‐1688.2010.00518.x Abstract: Headwater drainage features (first‐ to second‐order streams) are the capillaries of the landscape that, among other things, moderate the timing and volumes of water available to the riparian and aquatic ecosystems. How these features respond to summer rainfall is poorly understood. We studied how geology and an index of land use/land cover influenced peak flows following rainfall events in 110 headwater stream sites that were studied over a four‐month period during a drought year. Highest peak flows were observed in the most urbanized catchments and in poorly drained soils, but specific responses were variable depending on both geology and land disturbance. Redundancy analysis indicated that both surficial geology and land disturbance were important factors influencing peak flows under drought conditions. We conclude that responses of these headwater streams to individual storms during drought conditions are unpredictable from data collected using our methods, but increased peak flows were associated with increased urban and agricultural development, but mitigated by surficial geology. These findings demonstrate the challenges to accurately predict flow conditions in headwater streams during periods of extreme weather that concurrently have the greatest potential effect on biota. The combination of these challenges and importance of such events indicates the need to develop new approaches to study and manage these resources.     

Does marginal price matter? A regression discontinuity approach to estimating water demand

Although complex pricing schedules are increasingly common among water and electricity providers, it is difficult to determine whether consumers respond to changes in the pricing schedule because price changes are often confounded with simultaneous demand shocks or non-price policies. To overcome this challenge, we exploit a natural experiment - the introduction of a third price block in an increasing block pricing schedule for water - in Santa Cruz, California. Using a regression discontinuity design, we find that consumers do respond to changes in marginal price. Doubling marginal price leads to a 12% decrease in water use (500 cubic feet per bill) among high-use households.     

Safety Climate and Prediction of Ergonomic Behavior

One of the most important ways to prevent accidents is to consider safety climate or culture. Moreover, some studies suggest that behavior contributes to 86%-96% of all injuries. This cross-sectional study took place in an Iranian petrochemical company in 2010. Vinodkumar and Bhasi’s safety climate questionnaire and an ergonomic behavior sampling checklist were the data collection tools. Cronbach’s a for questionnaire reliability was .928. With reference to the results of a pilot study, a sample of 1755 was determined for behavior sampling. We used principal component analysis (PCA) to derive the coefficient of paths in the path model and the Anderson-Rabin method to calculate factor scores. The results showed that safety climate was an effective predictor of ergonomic behavior (p < .01). They also showed the importance of decreasing the number of workers with negative safety climate. Moreover, it is necessary to promote workers’ ergonomic behaviors in the workplace.     

Effects of Meteorological Parameters on Air Pollutant Concentrations in Elazig,Turkey

In the present study, air pollutant concentrations have been analyzed statistically with meteorological factors in the city of Elazig, which is located in the east Anatolia region of Turkey, for the months of September, October, November, December, January, February, March, and April during the years 2003 and 2004. SPSS code was used for statistical analyses. The relationship between monitored air pollutant concentrations, such as SO₂ and the total suspended particles (TSP) data, and meteorological factors such as wind speed, temperature, relative humidity and pressure was investigated. According to the results of linear and non-linear regression analysis, it was found that there is a moderate and weak level of relation between the air pollutant concentrations and the meteorological factors in Elazig. The correlation between the previous day's SO₂, TSP concentrations and actual concentrations of these pollutants on that day was investigated and the coefficient of determination R was found to be 0.80 and 0.76, respectively. The statistical models of SO₂ and TSP, including all of the meteorological parameters, gave an R of 0.50 and 0.40, respectively. Further, in order to develop this model, the previous day's SO₂ and TSP concentrations were added to the equations. The new model for SO₂ and TSP was improved considerably with R = 0.85 and 0.80, respectively.     

锯末对Cu~(2+)的吸附特性研究

以工业废弃物锯末为吸附剂,研究其对水中Cu2+的吸附特性.结果表明,锯末对Cu2+的吸附速度较快,1 h后基本达到平衡.准二级速率方程很好地模拟了吸附反应的动力学方程(R20.99).锯末对Cu2+吸附主要机制是离子交换,吸附量随pH升高而升高.离子强度对吸附反应有一定影响:Cu2+和锯末一部分是内层结合,一部分是外层结合.经过酸碱处理的锯末在吸附能力上有了一定程度的提高.Langmuir模型对原始锯末的吸附等温线拟合最好,Langmuir-Freundlich模型对经过酸碱处理的锯末拟合最好.热力学分析显示吸附反应具有自发性、放热、熵增特性.     

pH对Cd~(2+)离子在δ-MnO_2上的吸附与解吸的影响

研究了pH值对δ-MnO2对模拟废水中Cd2+的吸附作用的影响,当pH<2.3时,吸附率仅为20%,pH>5时Cd2+的吸附率在96%以上;吸附过程为非特性吸附,可以用Elovich方程和双速率方程来描述。吸附后δ-MnO2在pH<2.05时可以有效的解吸,解吸率约为75%。