额济纳绿洲沙尘暴沉积的物质特征

考察了额济纳绿洲内广泛分布的沙丘,并采集了称之“额济纳剖面”的典型沙丘不同粒级的样本263个,进行了25个化学元素的分析以及11个¹⁴测定.结果表明,该沙丘是距今2500年以来多次沙尘暴堆积的沉积记录.褐黄色风成沙层类似我国内陆沙漠沙,该地沙漠风沙流的产物;黄土状亚沙土与黄河中游的沙黄土、现代沙尘堆积极其相似,且结合历史时期“雨土”资料,说明其是沙尘暴的叠加产物;含红柳枯枝落叶的沙层则是兼有前两者成分的混合堆积.     

气溶胶稳定硫同位素研究进展

稳定硫同位素可以用来示踪硫酸盐气溶胶的来源、迁移和转化的过程.本文首先介绍了目前气溶胶稳定硫同位素相关的分析测试方法,即EA-IRMS、MC-ICPMS和NanoSIMS.归纳了国内外气溶胶δ34S的时空组成特征,两极和沿海区域气溶胶δ34S值普遍高于内陆区域;冬季燃煤和夏季生物排放作用使得气溶胶δ34S值冬高夏低.同...     

渔业复垦塌陷地抗生素抗性基因与微生物群落

水产养殖行业抗生素的广泛使用引起了抗生素抗性基因(antibiotic resistance genes,ARGs)污染问题.为探究渔业复垦塌陷地ARGs污染特征,利用宏基因组学技术检测分析了渔业复垦塌陷地ARGs的相对丰度和微生物群落结构.研究区域共检测出29种ARGs,bacA在所有样品中相对丰度最高,达1.96×...     

Ergonomics improvements of the visual inspection process in a printed circuit assembly factory.

An ergonomics improvement study was conducted on the visual inspection process of a printed circuit assembly (PCA) factory. The process was studied through subjective assessment and direct observation. Three problems were identified: operators' eye problems, insufficient time for inspection and ineffective visual inspection. These problems caused a huge yearly rejection cost of US 298,240 dollars, poor quality, customer dissatisfaction and poor occupational health and safety. Ergonomics interventions were made to rectify the problems: reduced usage of a magnifying glass, the use of less glaring inspection templates, inspection of only electrically non-tested components and introduction of a visual inspection sequence. The interventions produced savings in rejection cost, reduced operators' eye strain, headaches and watery eyes, lowered the defect percentage at customers' sites and increased the factory's productivity and customer satisfaction.     

The World Programme of Action: a new paradigm for population policy. The Cairo Conference

There has been considerable national and international debate over the past two years on population-related issues. Women have sought to affirm their right to control fertility and to have access to health services while criticizing current population policies and programs. A new paradigm for population policy has emerged from the debate, one which focuses upon providing broadly defined reproductive health services and acknowledges women's reproductive rights and their need for empowerment. This new population policy is embodied in the World Program of Action (WPOA) adopted September 1994 at the International Conference on Population and Development (ICPD) in Cairo, Egypt. WPOA is the main document emerging from the ICPD. It was developed and negotiated by participating governments during three preparatory committee meetings leading up to the conference and at ICPD itself, where it was adopted. The WPOA is slated for approval by the UN General Assembly during its current session. The WPOA is evidence of how effective women were in making women's rights and health the focus of an international document. The author discusses politics at the ICPD, the WPOA, funding the WPOA's implementation, the road ahead, and the power of women's strategies.     

Adsorption characteristics of Cu and Ni on Irish peat moss

Peat has been widely used as a low cost adsorbent to remove a variety of materials including organic compounds and heavy metals from water. Various functional groups in lignin allow such compounds to bind on active sites of peat. The adsorption of Cu(2+) and Ni(2+) from aqueous solutions on Irish peat moss was studied both as a pure ion and from their binary mixtures under both equilibrium and dynamic conditions in the concentration range of 5-100mg/L. The pH of the solutions containing either Cu(2+) or Ni(2+) was varied over a range of 2-8. The adsorption of Cu(2+) and Ni(+2) on peat was found to be pH dependent. The adsorption data could be fitted to a two-site Langmuir adsorption isotherm and the maximum adsorption capacity of peat was determined to be 17.6 mg/g for Cu(2+) and 14.5mg/g for Ni(2+) at 298 K when the initial concentration for both Cu(2+) and Ni(2+) was 100mg/L, and the pH of the solution was 4.0 and 4.5, respectively. Column studies were conducted to generate breakthrough data for both pure component and binary mixtures of copper and nickel. Desorption experiments showed that 2mM EDTA solution could be used to remove all of the adsorbed copper and nickel from the bed.     

基于JC法尾矿坝稳定性可靠度研究

论述了可靠度理论在尾矿坝稳定性评价中可有效弥补定值法(安全系数法)存在的不足。文中选用JC法作为可靠度分析方法,结合实例对尾矿坝进行稳定性分析,分别求出了尾矿坝在正常和洪水工况下运行时的可靠度指标。并通过与定值法(安全系数法)比较,发现可靠度指标对坝体材料物理力学参数变异性的敏感度高于安全系数,因而得出可靠度方法可以更加全面、客观的反映出尾矿坝稳定性的真实状态。     

如皋市工业源COD产排污强度及其产业构成分析

以第一次全国污染源普查数据为依据,分析了如皋市工业源COD产排污强度及其产业构成特征。不同行业群对GDP的贡献和对COD的贡献呈现明显倒挂,COD产排污大户主要集中在该市的一些传统产业,重点污染源企业治理水平明显高于一般污染源企业。在此基础上,就如皋工业源COD产排污水平、产业结构优化在降低COD产排污强度中的意义以及强化传统产业污染治理的主要途径等问题展开了讨论。