矿产勘查的新思路,新方法,新技术

本文总结了国外矿产勘查新思路，新方法、新技术、指出矿产勘查工作在由“实物工作量型”向“科学找矿型”转变；普查工作部置上由单一矿床转向整个成矿带，实现了矿产勘查思路从区域到局部的重大转变；同时，发展各种勘查方法及其有机结合是当今找隐伏矿的最重要途径。本文以勘查地球化学方法为例阐述了上述思路和方法。     

Changes in zooxanthellae density,morphology, and mitotic index in hermatypic corals and anemones exposed to cyanide

Sodium cyanide (NaCN) is widely used for the capture of reef fish throughout Southeast Asia and causes extensive fish mortality, but the effect of NaCN on reef corals remains debated. To document the impact of cyanide exposure on corals, the species Acropora millepora, Goniopora sp., Favites abdita, Trachyphyllia geoffrio, Plerogyra sp., Heliofungia actinformis, Euphyllia divisa, and Scarophyton sp., and the sea anemone Aiptasia pallida were exposed to varying concentrations of cyanide for varying time periods. Corals were exposed to 50, 100, 300, and 600 mg/l of cyanide ion (CN(-)) for 1-2 min (in seawater, the CN(-) forms hydrocyanic acid). These concentrations are much lower than those reportedly used by fish collectors. Exposed corals and anemones immediately retracted their tentacles and mesenterial filaments, and discharged copious amounts of mucus containing zooxanthellae. Gel electrophoreses techniques found changes in protein expression in both zooxanthellae and host tissue. Corals and anemones exposed to cyanide showed an immediate increase in mitotic cell division of their zooxenthellae, and a decrease in zooxanthellae density. In contrast, zooxanthellae cell division and density remained constant in controls. Histopathological changes included gastrodermal disruption, mesogleal degradation, and increased mucus in coral tissues. Zooxanthellae showed pigment loss, swelling, and deformation. Mortality occurred at all exposure levels. Exposed specimens experienced an increase in the ratio of gram-negative to gram-positive bacteria on the coral surface. The results demonstrate that exposure cyanide causes mortality to corals and anemones, even when applied at lower levels than that used by fish collectors. Even brief exposure to cyanide caused slow-acting and long-term damage to corals and their zooxanthellae.     

美国地球探测计划

2001年，美国国家科学基金会(NSF)、美国地调局(USCS)和美国国家航空航天局(NASA)联合发起了一项新的“地球探测”(Earthscope)计划。它是一套分布式、多用途仪器和观测台网的组合，目的是加深对北美大陆结构、演化和动力学特征的理解。     

大绝灭后的生物复苏

对生物复苏的一些关键问题提供了一些线索。概述了人们如何看待生物复苏、复苏的总体型式、哪些类群会复苏及如何幸存下来，绝灭和复苏之间的联系。随着研究的深入，许多问题得到了解决，也将提出一些新的假设。     

在地球科学与社会中岩石学的地位何在？

美国国家科学院出版社于１９９３年出版了美国对地球科学的首次国家级学科调查报告－《固体地球科学与社会》。报告的中心思想是建议大力支持对整个地球体系进行研究。本文总结了报告中列出的许多研究机会，其中包括火成岩和变质岩岩石学，证实在目前提倡研究的绝大部分重要地球作用中岩石学均有强烈的体现。岩石学以其观察、测量、实验与理论密切相结合而在各领域的前沿不断发展，并将继续成为多学科地球科学研究中一个重要的基础课     

国土资源部2002年科技成果回眸

在“三个代表”重要思想和“科学技术是第一生产力”的方针指导下,2002年度国土资源部系统广大科技工作者紧紧围绕国土资源领域的重大科学问题和关键技术开展攻关,圆满完成了国家重大科学工程、国家高技术研究发展计划、国家重点基础研究发展规划、国家科技攻关计划及部科技发展计划的各项任务,取得了一大批优秀成果。 本文主要以国土资源部科技成果管理办公室正式登记的科技成果为依据,介绍我     

Impacts of human activities on coral reef ecosystems of southern Taiwan: a long-term study

In July 2001, the National Museum of Marine Biology and Aquarium, co-sponsored by the Kenting National Park Headquarters and Taiwan's National Science Council, launched a Long-Term Ecological Research (LTER) program to monitor anthropogenic impacts on the ecosystems of southern Taiwan, specifically the coral reefs of Kenting National Park (KNP), which are facing an increasing amount of anthropogenic pressure. We found that the seawater of the reef flats along Nanwan Bay, Taiwan's southernmost embayment, was polluted by sewage discharge at certain monitoring stations. Furthermore, the consequently higher nutrient and suspended sediment levels had led to algal blooms and sediment smothering of shallow water corals at some sampling sites. Finally, our results show that, in addition to this influx of anthropogenically-derived sewage, increasing tourist numbers are correlated with decreasing shallow water coral cover, highlighting the urgency of a more proactive management plan for KNP's coral reefs.