Exploring the linkage between the home domain and absence from work: Health,motivation, or both?

The aim of this study was twofold. First, we examined depleting and enriching effects of employees' home domain (home demands and quality time spent at home) on unscheduled absence from work. Second, we tested the assumption of the medical and withdrawal models that absence duration and frequency are uniquely predicted by respectively health condition and job motivation. We used longitudinal, different‐source data from 1014 employees. The results showed that home quality time was negatively related to absence frequency and duration in the following year through a physical pathway (less physical stress symptoms and health complaints) and through a psychological pathway (less psychological stress symptoms, increased job motivation). Employees with heavy home demands reported more physical and psychological stress symptoms, more health complaints, and lower job motivation. Accordingly, they had longer and more frequent sick leaves in the consecutive year. We conclude that the home domain adds to our understanding of absence from work. In addition, the model including cross pathways between health complaints and job motivation on the one hand, and absence frequency and duration on the other, best fitted the data. Thus, a clear distinction between volitional absence (frequency) and absence due to illness (duration) seems hard to justify. Copyright © 2012 John Wiley & Sons, Ltd.     

Dynamic street environment

The research examines the street's physical characteristics that are influenced by the culture in the city of Mashhad, Iran as a case study. It is evident that new developments in the traditional street have mostly eroded the cultural value of the urban environment. The techniques used for data collection include literature review, in-depth interview, questionnaire and field observation. The research outcome indicated, firstly, the street's physical characteristics which were influenced by culture and shaped the street form and function as a corridor to the Holy Shrine, a significant Iranian landmark. It is indicated that culture is a way of life influencing the physical appearance, activities and behavioural aspects that these are important to support human needs, therefore to create a sense of place. Secondly, culture, in line with the physical characteristics, would enhance the uniqueness of the street and its cultural value to support distinctiveness of the street environment. The third finding proves that cultural aspects have a significant role in activating public life and increasing the attractiveness of the street.     

100 years running: The need to understand why employee physical activity benefits organizations

Employee physical activity initiatives are commonplace, but management scholarship has not kept pace with theoretical and empirical work to validate such initiatives. In this Incubator, we clarify the employee physical activity construct, present mechanisms linking physical activity to organizationally valued outcomes, and consider the dark side of employee physical activity initiatives. Copyright © 2015 John Wiley & Sons, Ltd.     

废弃线路板有价金属回收的物理处理工艺

线路板是绝大多数电子产品达到电路互连的不可缺少的主要组成部件,其中蕴合许多有价金属,如铜、铁、铝、锡、铅、金、银等,其回收方法以物理法为主。介绍了目前占主导地位的几种物理法回收技术及工艺流程,并且提出自己的湿法处理工艺。     

物理诱变育种技术在环境工程中的发展及运用

污水的生物处理具有重大意义,生物处理法与物理、化学法相比,具有经济、高效的优点。传统的污水处理技术在处置难降解有毒有机物以及进一步提高效率的过程中遇到了难以克服的困难。因此,诱变育种技术被运用到这一领域以改善这一局面。其中,物理诱变技术以其操作简单经济,突变率高,诱变产物对环境威胁相对较小而受到重视。常见的物理诱变技术主要为γ射线、紫外线和激光等几种方式,近年来,这些诱变技术在处理造纸黑液、脱氮除磷等实际应用方面成果显著。     

垃圾渗滤液净化物理化学处理方法研究

根据垃圾填埋场渗滤液成分复杂,有机物中氨氮浓度高,COD及BOD值较大,而且含有一定重金属离子的特点,采用物理化学处理方法进行处理。将有机物、重金属化学沉降,同时将滤液中的铵根离子转化为氨气,用鼓气的方法赶出氨气,再用絮凝剂混凝沉降的方法对渗滤液进行处理。经优化条件实验出水后的渗滤液基本达到《生活垃圾填埋污染控制标准》二级排放标准。     

东江源沿江村镇生活垃圾物理特性分析

东江系广东及香港的饮用水源地,其源区包括江西省赣州市的寻乌、安远和定南3县。本研究在东江源区选取了3个典型村庄,调查农村生活垃圾的产生量及物理特性。调查发现：东江源区农村生活垃圾主要以厨余类垃圾为主,可达60％以上;其次是灰土类垃圾,可达12％以上,其他组分一般在10％以下。县级村人均垃圾产生量一般在0.2~0.47 kg·d^-1,平均0.36 kg·d^-1;镇级村人均垃圾产生量在0.18~0.35 kg·d^-1,平均0.29 kg·d^-1;普通村人均垃圾产生量在0.07~0.33 kg·d^-1,平均0.17 kg·d^-1。混合生活垃圾含水率与厨余类垃圾所占的比例呈显著线性相关（R^2=0.626,P=0.019）。混合垃圾平均热值在2329 kJ·kg-1,不适合直接进行焚烧处理。     

典型水环境因素对聚酯微塑料沉降的影响机制研究

以聚酯（聚对苯二甲酸乙二醇酯,简称PET）微塑料为主要对象,研究电解质浓度,电解质类型及pH值等典型水环境因素对其沉降行为的影响机制.结果表明：水环境中PET微塑料的沉降随电解质浓度的升高而不断增强,其悬液标准化浓度（C/C₀）最低可降至0.64;同一类型电解质对水环境中PET微塑料沉降行为的影响程度相似,而与1-1型电解质（NaCl及KCl）相比,水环境中1-2型电解质（CaCl₂及MgCl₂）的存在能够显著促进PET微塑料的沉降;水环境中PET微塑料的沉降随pH值的增加而降低,随着pH值由10降至4,PET微塑料悬液的C/C₀由最高0.98下降至最高0.76.一阶动力学沉降模型能够较好的拟合水环境中PET微塑料的沉降行为.此外,DLVO （Derjaguin-Landau-Verwey-Overbeek）理论能够反映出PET微塑料沉降行为的变化趋势,其计算结果与实验结果吻合度较高.本研究结果有助于提高对微塑料环境行为的认识程度,同时能够为评估微塑料环境风险提供理论依据.     

一种浮游植物快速浓缩及固定方法的可靠性分析

为验证一种浮游植物快速浓缩固定方法——滤膜浓缩法的可靠性,采用“鲁戈氏液固定沉降法”和“滤膜浓缩法”同时鉴定了不同浮游植物浓度梯度水样,并进行了对比分析,结果表明：鲁戈氏液固定沉降法与滤膜浓缩法整体上均鉴定出7门,32属,但不同梯度上滤膜浓缩法鉴定出的浮游植物种类较多.两种方法门水平上除裸藻门（P<0.05）外丰度均无明显差异（P>0.05）,属水平上相对丰度99%以内的浮游植物均无明显差异（P>0.05）,即无论是门还是属水平上,滤膜浓缩法对浮游植物丰度的鉴定是可行的.采用两种方法得到的不同梯度下藻密度拟合方程斜率差异较小（P>0.05）且相关性显著（R²=0.958,P<0.01）,但滤膜浓缩法鉴定出的浮游植物细胞密度更大.整体来看,滤膜浓缩法得到的藻类鉴定结果与鲁戈氏液固定沉降法基本一致.     

北京市大气降水理化特性的演变及其重要的环境效应

通过采集北京市2018、2019和2021年大气降水样品,研究了北京市大气降水中主要金属元素和水溶性离子浓度,重金属、水溶性离子、溶解性无机氮（DIN）和无机硫（SO₄^2--S）湿沉降通量及其对生态环境的影响,以及典型降水过程对大气污染物的清除机制. 结果表明,研究期间北京市降水多呈中性或碱性,酸雨率极低,仅为3.06%. 2018、2019和2021年降水中主要金属元素总浓度依次为（4 787.46 ±4 704.31）、（7 663.07 ±8 395.05）和（2 629.13 ±2 369.51）μg·L^-1,离子总当量浓度依次为（851.68 ±649.16）、（973.98 ±850.94）和（644.31 ±531.16）μeq·L^-1,二者年际变化均表现为：2019年>2018年>2021年;春季、夏季、秋季和冬季的主要金属元素总浓度的季节均值分别为（9 624.25 ±7 327.92）、（4 088.67 ±5 710.14）、（3 357.68 ±3 995.64）和（6 203.19 ±3 857.43）μg·L^-1,春季、夏季、秋季和冬季的离子总当量浓度的季节均值分别为（1 014.71 ±512.21）、（729.83 ±589.90）、（724.35 ±681.40）和（1 014.03 ±359.67） μeq·L^-1,二者季节变化均表现为：春季>冬季>夏季>秋季. NO₃^-和SO₄^2-是主要的致酸离子,而NH₄⁺和Ca²⁺是主要的酸中和离子. 值得注意的是重金属Cd的湿沉降通量虽然较低,仅占所有重金属湿沉降通量的（0.13 ±0.04）%,但Cd的土壤安全年限为291 a,显著低于其他重金属,因此,其生态风险相对较高. 水溶性离子NH₄⁺、Ca²⁺、NO₃^-和SO₄^2-的湿沉降通量占总离子湿沉降通量的（85.72 ±2.18）%,对生态环境的综合影响可能较大. DIN湿沉降通量主要以NH₄⁺-N为特征,在夏季对生态环境具有重要的促进作用. SO₄^2--S湿沉降通量在夏季较高,对生态环境的促进作用较大. 大气降水对污染物的清除作用受诸多因素影响,这些因素协同作用直接影响降水对污染物的清除机制.