北海斯卡格拉克东部碳酸盐沉积物的破坏性成岩作用

<正> 岩石学的饱和度测量在浅海水里,碳酸盐沉积物的溶解作用是一个有争议而且了解很少的作用,这一现象最近已经在北海斯卡格拉克地区发现(Alexanderson,1957,1976)。沿瑞典海岸的海岸群岛,研究了0—40米深度的滨外钙质砂的溶解作用和100—150米深度的近     

消除酒槽废液污染及其能量回收

为了防止酒槽废液进入作业区,一九八一年六月在泰国曼谷建起了一间处理洒槽废液的工厂。蒸馏车间所安装的处理设备是世界上第一套处理甘蔗糖蜜酒槽废液的设备。     

金伯利岩同源包体的形成及其成因

<正> 在金伯利岩的变种当中,同源包体角砾岩占有特殊的地位。它们的形态特点是存在有各种形成体——同源包体,同源包体在岩石中的含量一般为5—30％。同源包体的形成体就是金伯利岩中的球状和椭球状的金伯利岩包体,它们与其周围的金伯利岩母体在充填基斑晶和矿物的结构、比例和尺寸上以及总的化学成分和一系列稀有元素的含量上都是不同的。对于同源包体的告石学描述,在等(1959,1964)、(1962)、(1967)、(1976)和C.R.Clement(1973)的著作中均可查阅到。同源包体     

辉长岩与伴生花岗岩类成因联系的岩石化学标准

在贫水花岗岩类系列(辉长岩-花岗岩、英云辉长岩-花岗闪长岩及石英二长岩-花岗岩)的主要类型中,辉长岩类形成较早,其数量从第一类型到最后娄型逐渐减少。不同研究人员对于辉长岩类在上述系列中起的作用评价不一。本文作者基于上述各类型岩石化学分析,提出如下看法,在辉长岩(这是花岗岩类系列母体岩浆的结晶产物)的辉长岩-花岗岩伴生类型以及在英云辉长岩-花岗闪长岩组合中,辉长岩或是早期结晶相的积聚集合体,或者是这些早期结晶相与原来的安山质岩浆发生混染所形成的。     

加拿大不列颠哥伦比亚省布卢柏尔矿区铅锌矿的气液包裹体和同位素研究

在布卢柏尔(Bluebell)铅锌矿,其90％以上的矿体是作为布卢柏尔灰岩的交代产物出现的,灰岩厚度为100—150呎,时代属寒武纪早期。并且经受了强烈的区域变质作用。矿是沿裂隙分布的,并与煌斑岩有关。     

Toxicological study of plant extracts on termite and laboratory animals

Toxic activity of leaf extracts of Polygonum hydropiper L. and Pogostemon parviflorus Benth. were tested in the laboratory against tea termite, Odontotermes assamensis Holm. Both the tested extracts caused mortality of the termite. The highest toxic activity (100%) was found in the 2.0% chloroform extracts of P. hydropiper. The chloroform extract of P. hydropiper was explored for possible mammalian toxicological effects. The LD50 was 758.58 mg/kg in male albino mice. Subcutaneous injection of sub-lethal dose of extract into male mice once a week for 6 weeks failed to express any significant influence on WBC, RBC count and blood cholesterol.     

Effect of organochlorine contaminants and individual biological traits on blubber retinoid concentrations in bottlenose dolphins (Tursiops truncatus)

Here we assessed retinoids as biomarkers of contaminant exposure by studying whether the sex, age, lipid content and organochlorine concentrations of bottlenose dolphins induced variation in retinoid status and its deposition in blubber. Blubber samples were collected from 47 individuals of known age and gender from Sarasota Bay in June 2000 and 2001. The sample included a representative cross-section of the resident dolphin community, with ages ranging from 2 to 50 years. Organochlorine levels showed the age- and sex-related variation commonly observed in other species, with concentrations increasing in youngsters of both sexes and in adult males, and decreasing in adult females after the onset of maturity. Blubber lipid content was low in the overall population and significantly decreased with age in adult males. Retinoid blubber concentrations were comparable to other odontocete species previously studied, and were strongly determined by lipid content. As a consequence of the latter, retinoid concentration was observed to decrease with age in adult males. This effect could not be statistically dissociated from the negative correlation observed between levels of organochlorines and retinoid blubber concentration. Consequently, we could not clarify whether high organochlorine loads in this population lowered retinoid concentrations or, conversely, whether depleted lipid reserves were indeed responsible for the high organochlorine concentrations and the low retinoid levels detected in blubber. With the current knowledge, both options should be considered and investigated, with initial focus on male dolphins.     

Geochemistry and bioavailability of metals in sediments from northern San Francisco Bay

In this study, metals (Be, Cr, Mn, Fe, Ni, Cu, Zn, Ag, Cd, Pb and Hg) in the fine-grained fraction (<63 microm) from 12 sites at different locations in northern San Francisco Bay over a year period from March 2000 to March 2001 were analyzed after acid extraction. The results showed that metal concentrations in the sediments varied from site to site, whereas some of them were found elevated with respect to the sediment of Tomales Bay, CA, which has little contamination history, indicating an enrichment of the metals in the sediment samples analyzed. Sediment toxicity and bioaccumulation evaluation by a clam species, Macoma nasuta, exposed to the sediment samples collected from the six sampling sites was carried out. The results showed that the sediment samples tested significantly reduced clam survival. Toxicity of the sediments to the clam was, in part, related to elevated metal concentrations in the sediments. In order to examine geochemistry of the metals and to understand potential correlations between metal concentrations and geochemical matrix elements of the sediments, bioavailability and toxicity of the metals, detailed analysis of metal concentrations associated with total organic carbon and the Fe-oxy-hydroxides in the sediment samples was performed. The analysis showed that sediment geochemistry appeared to influence metal bioavailability and may have important impacts on the toxicity of these metals to the clam.     

Radioactivity of the soil in Vojvodina (northern province of Serbia and Montenegro)

The widespread public belief that during the bombardment of Vojvodina (Yugoslavia) this region was contaminated by depleted uranium has recently raised public concern with respect to the potential contamination of agricultural products due to soil radioactivity. Based on the gamma-spectrometric analysis of 50 soil samples taken from the region of Vojvodina we concluded that there is no increase of radioactivity that could endanger the food production. Taking into account the transfer factors of 137Cs to plants, the measured activity concentrations of this isotope should not endanger the health safety of the produced food. No traces of depleted uranium have been found. The natural radioactivity levels are compared with the results form other countries.     

Colonization of surfaces by phenolic compounds utilizing microorganisms

The aim of the present study is to determine optimal adhesive interaction of phenolic compounds utilizing Candida maltosa and Rhodococcus erythropolis when adhering to kaolin, silicone, synthetic foil (Steriking R40) and fluorinated silicones, comparing cell and support surface hydrophobicity. In parallel, the interfering effect of detergents was investigated. Data obtained show that the less hydrophobic supports display high initial cell adhesion when contacted with the cell type with a lower surface hydrophobicity (yeast cell) but most stable yeast biofilms are those formed on highly hydrophobic fluorinated silicones. On the other hand, support hydrophobicity has no effect on bacterial cell detachment; however, bacterial biofilms are denser when growing on more hydrophobic supports. Both detergents interfere (independently on the cell type) with the early and late phases of biofilm development.