Comparative studies on the concentration of rare earth elements and heavy metals in the atmospheric particulate matter in Beijing, China, and in Delft, The Netherlands

Atmospheric particulate matter (APM) was collected at three sampling sites in Beijing, China, from February to June 1998. The concentrations of rare earth elements (REE) and cobalt (Co), zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) in the APM were determined by inductively coupled plasma mass spectrometry (ICP-MS). The results obtained in Beijing, China, were compared to that obtained in Delft, the Netherlands, in 1997. The influence of coal combustion was considered. The results demonstrated that the content of APM, the concentrations of REE and Co, Zn, Cd, Pb in the APM in Beijing, China, were higher than that in Delft, the Netherlands. From the ratios of La to Ce, and La to Sm, which may be used as tracers for the origin of the REE, it is concluded that the origins of REE in China differ from those in the Netherlands.     

Characterisation of projectiles composed of depleted uranium

Projectiles suspected to be composed of depleted uranium (DU) were found in Kosovo. Their properties were analysed using alpha and gamma ray spectrometry, mass spectrometry and electron microscopy. They were found to be composed of DU with small amounts of other elements such as Ti. 236U was detected in the penetrators, reflecting the use of reprocessed fuel. No transuranium elements were detected. The typical external dose rate meter is not the best option for mapping the location of penetrators from the ground. Monte Carlo calculations were performed in estimating possible skin doses. Penetrators in long-lasting contact with skin may cause a notable equivalent dose to skin.     

3瑞士公司和可持续发展;一种志愿举措

３瑞士公司这家法国邮购公司已走上了可持续发展之路，从１９９０年以来，该公司采取了讲求实效和的全面环保政策。本文叙述了在这方面所开展的主要活动。     

沙漠地带获得农业用水的一种方法——“卡丁”

前言在干旱地区,雨水稀少而且变化无常,任何地表水源,水量再小也是宝贵的。许多干旱环境中,地下水太深或含盐量很高,也不能利用。在印度的干旱地带—特别是在拉贾斯坦的加索麦地区(包括塔尔沙漠的一部分)—靠所谓“雨季”的雨水,不能满足大部分庄稼的需要。因雨季的雨水很不稳定,而且主要土壤多半是砂丘、薄砂砾层或岩石。因此,大规模     

用液体离子交换剂—分光光度法测定和分离环境样品中的微量钛

笔者基于直接测量已吸收了源于样品的显色络合物的液体离子交换剂相所产生的光吸收,研制出一种测定微量钛的灵敏而又具有选择性的方法。在硫氰酸盐存在下,用液体离子交换剂Aliquat336萃取钛(Ⅳ)-苯氧肟酸(BHA)络合物的灵敏度比用己醇或异戊醇萃取钛(Ⅳ)-BHA络合物的灵敏度高10倍。本法可用于富集、测定和分离金属含量极低的工业废液和环境样品中的钛(Ⅳ)。     

……贫乏的水源贫穷的人民贫乏的水源……

“在发展中世界几乎每3个人当中便有一个(即约12亿人口)无法得到安全而又可靠的水源供应以满足其日常生活的需要。他们常常不得不借助于很可能已含有动物粪便的浅水井或死水潭来消解燃眉之急。其结果是,各种水传疾病约占发展中国家疾病总数的80％。妇女和儿童每日为了取得足够的水用于饮用、煮食和清洗,便需跋涉数公里之遥;这种日常负担耗尽了她们的时间和精力,使她们无法分身去从事更具生产     

世界磷矿石的供需状况

本文论述了全世界磷矿石的供需状况,展望了未来磷矿石的资源量及其市场前景。一、世界磷矿石工业磷矿石与氮、钾肥是全世界发展农业必不可少的物质。当土壤中缺乏这些物质时,必须进行补充,粮食才能获得高产。在全世界的化肥使用量中,磷肥占85%～95%.本文所指的磷矿石是已开采或选矿后的产品。磷矿石可通过湿处理而转换成磷酸,通过电炉加热而析出磷,或可直接应用于酸性土壤中。1.产量1985年世界上30个国家的磷矿石产量见表1。从表1所见,美国、苏联和摩洛哥是世界上最大的3     

地表沉积物中的金球

<正> 最近在安大略东北阿比蒂比克莱伊带的冰碛物中发现了金球(直径0.05——0.2mm),这对某些砂金超源于化学沉淀提供了证据。一些深埋的不连续层位样品的重砂,含有高达     

格陵兰冰盖在末次间冰期大范围消融的冰岩心证据

加拿大北极群岛(CAI)以及格陵兰的森楚里营(CC)和Dye-3的冰岩心底层冰的证据表明,在比100ka还早的末次间冰期期间,格陵兰冰盖发生了大范围或完全消融,这与早先的解释大不相同。以前人们认为,底层冰中杂质微粒的存在表明,冰盖底层发生过消融,这些冰开始形成的时间证据已遭破坏。然而,当冰帽和冰盖的面积大大缩小时,这些微粒极可能被风吹到冰盖面上来。冰的结构、气体含量和其它证据也表明,每个钻孔位的底层冰为重叠冰,是冰帽或冰盖早期生长阶段的一种典型的冰类型。如果现代冰层是在末次间冰期期间开始生长的,那么在较早(伊利诺斯冰期)形成的冰盖必定在末次间冰期的较早阶段就已全部或大部分消融了。如果这种消融事件确实发生了,那么就象有人曾指出的那样,桑加门间冰期期间的海平面比现在高6m这种变化就不应归因于西南极冰盖的崩解。