WATER QUALITY STUDIES IN MALAYSIAN DISUSED MAN MADE LAKFS FOR SUITABILITY OF AN AQUACULTURE PROJECT

A study has been conducted on the status of water quality in two disused man made lakes, which have potential for cage aquaculture project. This study highlights the quality of water analyzed with reference to various physical - chemical parameters in two selected lakes and their suitability for fish farming. A number of parameters were measured including the amount of NH3 - N, NO3 - N, NO2 - N and total phosphorus while in - situ measurement including DO, pH, temperature, conductivity, TDS and Secchi disk visibility. Beside the physical -chemical of water, the location, morphometry and climate conditions were also investigated. The chemical data analyzed for six months indicated that Lake A and Lake B are characterized by relatively high DO, slightly neutral pH and low TSS. The concentration of NH3 -N and NO2 -N was very low （0. 058 mg/L and 0. 04 mg/L, respectively） and total phosphorus was usually in low concentration and sometimes would seem negligible. Besides, NO3 - N occurred in slightly higher concentration （1.75 mg/L）. Results obtained indicated that the study site has high potentiality for development of inland fisheries practices.     

The Timing of the Palaeoproterozoic Great Oxidation Event using Dykes,Sills and Bolcanics of the Ongeluk Large Igneous Province,Kaapvaal Craton

正The Neoarchaean to Palaeoproterozoic Transvaal Supergroup of the Kaapvaal Craton,southern Africa,is one of the best-preserved and most complete stratigraphic records across a critical in juncture in the Earth’s history.     

广东海丰自然保护区湿地现状及保护对策

广东海丰湿地是中国华南亚热带滨海湿地的典型代表,也是南中国海生态系统的重要组成部分,为多种珍稀、濒危鸟类和候鸟提供重要栖息地和迁徙中转站,具有重要的保护价值。在野外湿地资源调查的基础上,阐述了海丰自然保护区湿地类型与特点、湿地动植物资源、湿地利用现状等生态特征,分析了湿地面临的主要威胁,提出湿地生态系统保护与管理的主要对策和措施。     

Effects of heavy metal (Pb) concentration on some growth parameters of plants grown in lead polluted soil under organic fertilizer amendment

This study investigated morphological variation and biomass accumulation that occurred in Sida acuta and Chromolaena odorata plants grown in lead polluted soil under organic fertilizer amendment. The study was carried out in the screen house at the Biological Gardens of the Obafemi Awolowo University, Ile-Ife, Osun State. The experiment was a factorial combination of one heavy metal (Pb) at five levels of concentration (0, 200, 400, 800 and 1,000 mg/kg) in a completely randomized design, and were replicated three times for each of the two plants and two levels (0 g/kg and 9.4 g/kg) of organic fertilizer (OBD-Plus). Each pot was filled with 5 kg of air-dried and sieved soil and placed on a plastic tray for the collection of excess water. Two weeks after planting, seedlings of uniform height were transplanted from the nursery to experimental pots at the rate of one seedling per pot and grown for 10 weeks. The growth parameters of the plants were biomonitored for 7 weeks. After 10 weeks of treatment, the plants were harvested and dried to calculate the biomass accumulation. The two plant species performed better under fertilizer application than without it. For each of the plant species the growth parameters decreased as the levels of Pb concentration increased. Furthermore, the plants' biomass decreased significantly (p<0.05) as the levels of Pb concentration increased. The organic fertilizer helped to improve the plants' performance in lead-polluted soil.     

塔里木陆块西北缘萨热克砂岩型铜矿床构造-流体演化对成矿的制约

塔里木陆块西北缘萨热克砂岩型铜矿床构造演化、流体演化与成矿之间具有密切关系,处于一个统一系统中。矿床成岩期方解石中包裹体水的δD值为-65.3‰~-99.2‰,改造成矿期石英包裹体水的δD值为-77.7‰~-96.3‰,成岩成矿期成矿流体δ~(18)OH_2O变化范围为-3.22‰~1.84‰,改造成矿期成矿流体δ~(18)OH_2O变化范围为-4.26‰~5.14‰,指示萨热克铜矿成岩期、改造期成矿流体主要为中生代大气降水及其经水岩作用而成的盆地卤水。矿石中辉铜矿δ~(34)S值为-24.7‰~-15.4‰,指示硫主要源自硫酸盐细菌与有机质还原,部分源于有机硫。构造与成矿流体演化对砂岩铜矿成矿起关键制约作用。盆地发展早期强烈的抬升运动使盆地周缘基底与古生界剥蚀,为富铜矿源层的形成提供了丰富物源,至晚侏罗世盆地发展晚期,长期演化积聚的巨量含矿流体在库孜贡苏组砾岩胶结物及裂隙中富集,在萨热克巴依盆地内形成具有经济意义的砂岩型铜矿床。     

国产推扫式测图卫星影像几何精度评估模型

系统全面地分析并论证了国产推扫式测图卫星影像的几何精度,对卫星测图应用以及后续测绘卫星设计等都具有积极意义。从测图卫星几何成像机理出发,较为系统地分析了卫星成像过程中的轨道误差、姿态误差、时间误差、相机内部误差和星载设备安装误差等对卫星影像平面和高程几何定位误差的影响状况,定量分析并推导了各类误差源对影像几何精度的影响程度,设计并提出了国产推扫式测图卫星影像几何精度评估模型和方法。采用资源三号卫星立体影像开展实验,结果表明,所提出的影像几何精度评估模型获取的理论精度与实验精度符合度较好,模型具有合理性和科学性。     

Lead contamination of small cetaceans in European waters--the use of stable isotopes for identifying the sources of lead exposure

Lead concentrations and isotopic composition have been measured in bone and teeth of small cetaceans belonging to three species (Delphinus delphis, Phocoena phocoena and Stenella coeruleoalba), to evaluate the toxicological risk and to determine sources of lead in the European waters. Lead concentrations, far lower than threshold value inducing toxic effects in human, were higher in teeth than in bones, but highly correlated between the two tissues (r=0.92, p<0.001). Large variations of 206Pb/207Pb values in bone tissue showed that cetaceans must be submitted to various atmospheric influences. No geographical differences appeared which is consistent with studies on their distribution indicating seasonal movements between Brittany waters and the Bay of Biscay. The negative correlation between 206Pb/207Pb ratios and age of the individuals reflected the decrease in the production of alkyl lead in Europe, i.e., the increasing use of unleaded gasoline.     

香港西贡滨珊瑚REE的地球化学特征及其与海平面变化的关系

用ICP-MS技术测定了位于珠江口西岸香港西贡滨珊瑚在1991～2002年(分辨率达到0.5a)的稀土元素(REE)含量。实验结果显示香港滨珊瑚REE具有Ce负异常、重稀土富集这种典型的海水相分布模式。香港滨珊瑚中REE含量处于目前已见报道中的高值范围,与巴布亚新几内亚珊瑚的REE含量相当。通过与不同地区的比较,香港珊瑚高REE含量很可能就是毗邻的珠江水体高REE的直接反映,而且同南海北缘半封闭边缘海的性质有关。香港珊瑚REE的来源主要为珠江口及其相邻的陆缘沉积物。此外,1991～2002年香港珊瑚REE含量年际下降趋势十分明显,Ce负异常和重稀土富集的程度也呈加剧的趋势,分布模式向海水相转化。REE含量与海平面的年际变化之间有显著的负相关关系(r=-0.7～-0.9),而且重稀土与海平面的相关系数优于轻稀土。上述结果揭示了热带滨珊瑚对近期全球变暖、极冰融化和海水膨胀所引起的海平面快速上升的响应。