Chlorophyll-deficient propagules of Avicennia marina and apparent longer term deterioration of mangrove fitness in oil-polluted sediments

A correlation between petroleum hydrocarbon concentrations in sediments and chlorophyll-deficient mutations in mangroves may occur also in Australian mangroves. Earlier reports of such mutations in the Caribbean area were evident in viviparous propagules of the common mangrove genera, Rhizophora, borne on otherwise normal trees. These mutant propagules were termed albinos' since they lacked chlorophyll and normal green coloration, leaving them white, yellow or red. The mutation was considered lethal since newly established albino seedlings appeared unable to survive more than a few months. Our preliminary investigation of mangroves in SE Queensland found a similar mutation in another common mangrove genus, Avicennia, and this was apparently also correlated with oil concentrations in sediments. Although, more evidence is required, an apparently similar relationship shows that whatever caused the mutations may act commonly across a diverse range of plant types in quite separate locations. How widespread might this mutation be in mangroves? How many genera and species are affected? Are all occurrences correlated with oil in sediments? Does oil cause the mutation? We discuss these important questions and the potentially serious implications to coastal management where high mutant densities may be indicative of longer term genetic deterioration of mangrove habitat in oil-polluted wetland environments.     

隐伏矿的地球化学找矿方法技术研究

本课题是“七五”国家重点科技攻关项目。从1986年12月始至1990年5月结束,在历时近五年的时间内,通过三个地区两类不同的隐伏矿床上开展的岩石、土壤、气体、矿物以及面积性水化学测量等项试验研究工作,经分析研究综合获得如下主要成果:     

巴西里约热内卢塞佩蒂巴湾地区冶炼厂附近沉积物中As的浓度

自６０年代起，由于Ｚｎ冶炼工业的建立，位于塞佩蒂巴湾区的恩热纽海湾正在发生着变化。在化学生产过程中，Ａｓ用于纯化矿石。研究结果表明，大部分样品高于正常Ａｓ含量水平，在靠近工厂排污口强的结合部分中，Ａｓ达到３６０ｍｇ＾－１。在剖面２８ｃｍ深度的弱结合部分中Ａｓ达１４０ｍｇｋｇ＾－１。     

China: population change and population control

Since 1949 China's population has increased by 500 million and thereby grown at an average rate of 2 % per year. Annual growth rates have varied dramatically, falling from 3.3 % in 1963 to 1.2 % in 1979 and registering a population decline of 13.5 million in the famine years of 1960/61. China's demographic disaster in 1958/61 ranks as one of the most devastating in the history of the world. Chinese leaders have oscillated between pro- and anti-natalist policies. However, in the 1970s the government launched its third, its most intensive and to date its most successful family planning programme. So succesful that the total fertility rate declined from 6.4 in 1968 to 2.2 in 1980 and the level of contraceptive use in China was raised to the levels currently experienced in the Developed World. Despite the high rate of contraceptive prevalence, induced abortion is still extensively used to prevent unplanned births. The extent to which China's birth control programme has been implemented on a voluntary, coercive or compulsory basis is open to question. A rapid increase in the age of marriage and a substantial improvement in female education have made important contributions to the decline in fertility. Large differences in fertility exist between rural and urban China, reflecting significant differences in the average age of marriage and the very marked difference in educational attainment between the cities and the countryside. Whether the government directed family planning programme or socio-economic development has had the greatest impact on the decline in fertility, is under discussion. Whatever the motive force, the pace of demographic modernisation has been impressive and by international standards China now enjoys advanced levels of demographic development at an early stage of economic development.Abbreviations CMP-SPRCP-75-114 China Mainland Press, Survey of People's Republic of China Press 1975, No. 114. - FBIS-CHI-83-112 Foreign Broadcast Information Service, Daily Report, China, 1983, No. 112. - JPRS-CPS-85-012 Joint Publications Research Service, China Report, Political, Sociological and Military Affairs, 1985, No. 12. - SWB/FE/6246/BII Summary of World Broadcast, Far East, No. 6246, section BII.     

GPS与电视信号二者可兼容吗？

１９９１年１１月，飞利蒲实验室（ＰＬ）的地球物理研究会与Ｐｕｒｄｕｅ合作，在密西西比州的Ｉｎｖｅｖｎｅｓｓ附近采用ＧＰＳ测量在６１０米的ＷＡＢＧ电视发射塔周围进行。所获数据用于ＰＬ制定方案研究牛顿重力分离的可能性。数据采集范围为距塔８公里的半径内。在２公里以内，六台ＧＰＳ接收机有半数不能锁定ＧＰＳ信号。笔者认为某睦塔发送的微波信号干扰了ＧＰＳ卫星发送的信号。     

蔡家营铅锌银矿床原生异常模式

本文据蔡家营铅锌银矿床有关的各类介质中微量元素的分布及组合关系,确定了该矿床的指示元素,阐明了矿床原生异常特征及分带规律。结合矿床地质特征建立了该矿床的地球化学原生异常模式。取得了找盲矿的显着效果。     

铅硫同位素在地球化学勘查中的应用

铅硫同位素用于地球化学勘查是一项探索性的工作。为进一步证实其在多金属矿床勘查中的作用,选择热液铅锌矿床开展铅同位素追踪深部矿体试验,选择斑岩型铜矿床开展硫同位素识别矿化蚀变分带试验及δ34S垂向变化规律探讨。试验结果表明,铅同位素组成和三维拓扑V值可预测深部矿体,由上而下,数值增高预示着深部还有矿体;水平方向上,δ34S均值由高温蚀变区到低温蚀变区呈现出增高的趋势,此特点可用于鉴别矿化蚀变分带;垂直方向上,矿体δ34S均值总体随深度增加逐渐增大,若不同层位(标高)的岩石性质及其硫同位素背景存在差异,当其与成矿溶液叠加后,可导致δ34S均值呈跳跃式变化。