塔吉克斯坦某些岩石和矿石中铂族元素的分布

<正> 铂族元素的地球化学特征的研究只是个开端。这与铂族元素在天然地质体中的含量太低有关。近年来,测定铂族元素和贵金属的物理化学方法(能测定的浓度为1×10~(-7)—1×10~(-8)%)得到了顺利地发展,但在大多数情况下,还必须事先对金属进行浓缩和分离。О.Е.Юшко-Захарова等(1969)对岩石中Pt和Pd的克拉克值进行了初步地估算(g/     

微量进样注射-火焰原子吸收光谱法测定硅酸盐岩石和四个新的加拿大铁建造参考物料中的钪、钇和镧系元素

<正> 关于稀土元素丰度的研究对岩石成因模式讨论要求建立快速测定各种不同的火成岩、沉积岩和造岩矿物中稀土元素的分析方法。早先报道了一种测定某些矿物岩石中的 Y、Nd、Eu、Dy、Ho、Er、Tm 和 Yb 的原子吸收光谱法,它是将样品溶液(含1%La 作光谱缓冲剂的高氯酸盐乙醇介质)直接抽吸进入氧化亚氮-乙炔焰。而稀土元素(REE)是先通过草酸钙共     

24、用电化学和紫外检测的高压液相色谱法测定卤代苯胺及有关化合物

卤代苯胺可以从各种渠道包括农药、除莠剂、杀菌剂的代谢作用,工业废料和硝基取代芳香化合物的还原而进入环境中。由于苯胺类化合物有毒所以要求在环境中监测。以前用气相色谱法,需要进行衍生化;而且某些被卤代的代谢物还不能被分离。本文研究的高压液相色谱法可在无衍生化步骤的情况下进行分离,并检测出亚毫微克量的物质。这些化合物是用商品c-18键合相柱分离的,并用价廉的电化学检定器检测至亚毫微克量级。同时还研究了快速但灵敏度很低的紫外线方法。列举了各种化合物的色谱图和灵敏度数据。讨论了电化学检定的应用和限度。     

Water solubility enhancements of pyrene by single and mixed surfactant solutions

ＩｎｔｒｏｄｕｃｔｉｏｎＳｕｒｆａｃｔａｎｔｓｅｎｈａｎｃｅｔｈｅｒｅｍｅｄｉａｔｉｏｎｏｆＮＡＰＬ ｃｏｎｔａｍｉｎａｔｅｄｓｉｔｅｓｂｙｉｎｃｒｅａｓｉｎｇｔｈｅａｑｕｅｏｕｓ ｐｈａｓｅｃｏｎｃｅｎｔｒａｔｉｏｎｏｆｔｈｅＮＡＰＬｖｉａｍｉｃｅｌｌｅｆｏｒｍａｔｉｏｎ ,ｍｉｃｒｏｅｍｕｌｓｉｆｉｃａｔｉｏｎ ,ｏｒｍｏｂｉｌｉｚｉｎｇｔｈｅＮＡＰＬｐｈａｓｅ (Ｋｉｌｅ ,1989;Ｅｄｗａｒｄｓ,1991;Ｇｕｈａ ,1998ａ ;Ｋｏ ,1998;Ｚｉｍｍｅｒｍａｎ ,1999;Ｂｅｔｔａｈａｒ,1999;Ｗｉｌｌｓｏｎ ,1999;Ｐａ…     

Removal of copper from a copper sulphate solution using an ultrasonic-electrolysis process

The application of ultrasonic-electrolysis process for the removal of copper is studied.In the ultrasonic field cavitation acts as jets and agitates the solution and breaks the barrier layer between the cathode surface and the bulk of the solution.Thus increases metal deposition on the cathode surface.The results show that an ultrasonic field is successful for the removal of low copper concentrations in solution.     

Determination and discussion hydraulic retention time in membrane bioreactor system

Based on the microorganism kinetic model, the formula for computing hydraulic retention time in a membrane bioreactor system (MBR) is derived. With considering HRT as an evaluation index a combinational approach was used to discuss factors which have an effect on MBR. As a result, the influencing factors were listed in order from strength to weakness as: maximum specific removal rate K, saturation constant Ks, maintenance coefficient m, maximum specific growth rate ,ua and observed yield coefficient Yobs. Moreover, the formula was simplified, whose parameters were experimentally determined in petrochemical wastewater treatment. The simplified formula is θ= 1.1( 1/β -1)(Kｓ S)/KXo , for oetroehemical wastewater treatment K and Ko eaualed 0.185 and 154.2, resoectively.     

内布拉斯加州第四记冰碛年龄

<正> 北美第四纪沉积物曾有过一段漫长而有趣的历史。内布拉斯加州的第四纪沉积物是很重要的,因为许多经济活动都依赖于这些堆积物上发育的土壤和从沉积物中汲出的水,建筑材料也采自这些沉积物。从某种意义上说,几乎所有从事陆地上工作的人都是第四纪研究者,农民注意各种土类的差异和散布于内布拉斯加东部冰川作用区周围的奇特“外来石”景观,打井工人都熟悉这些沉积地层和埋藏在古河道中呈“脉状”     

SPATIO-TEMPORAL CHANGE OF DROUGHT DISASTER IN CHINA IN RECENT FIFTY YEARS

Foreword　Inglobalview ,droughtdisasterisregardedasthemostserioustypeofnaturaldisasterintheworld ,whichhascausedthewidestrangeofeffectsandthebiggesteconomiclosses .Se veredroughtsmainlyoccurinAfrica ,India ,China ,formerSovietUnion ,NorthAmerica ,andAustralia,accountingforalmosthalfofcountriesintheworld .Droughtdisasteroccursfre quentlyinChina ,withwiderangeofinfluence ,whichisthemostseriousmeteorologicaldisas ter ,causingeconomiclossesinagriculture .Fromthe 50’stothe 80’sinthe 2 0thcent…     

FRACTAL DIMENSION ANALYSIS APPLIED TO THE 7 DRAINAGE BASINS AND THE FLOOD IN CHINA

Foreword　Asoneofthethreegreatdiscoveriesin 1 970s ,thefractaltheoryhasbeenwidelyappliedinmanyfieldsconcerningthesciencesofnatureandthehumanities .Atpresent ,thefractaltheoryhasbeenappliedintherelatedanalysisofwatersystemordisaster .However ,thestud iesonnatureofrelationshipbetweenthewholewatersysteminChinaanddisasterfractalanaly sisarestillintheirinitialperiod .Thepaperpresentsafractaldimensionof 7drainagebasinsandthefloodinChinaaswellastheirpossiblerelations .Itishopedthatthepaperwouldbehe…     

指导环保事业发展的纲领性文件

在"十一五"即将起步之时,在全面建设小康社会的关键时期,国务院发布了<关于落实科学发展观加强环境保护的决定>(以下简称<决定>),这是深入贯彻十六届五中全会精神,落实科学发展观,构建社会主义和谐社会,指导我国经济、社会与环境协调发展的一份纲领性文件.深入学习贯彻<决定>,对于广泛调动全社会力量,加快推进环保事业发展,实现全面建设小康社会的宏伟目标将产生巨大的推动作用.