重金属Cu的土壤微生物毒性研究

Cu进入土壤后的早阶段，低浓度对土壤微生物生物量有刺激作用，而高浓度则起抑制作用；表现在微生物呼吸强度升高，微生物生理生态参数代谢商qCO2增大，微生物生物量碳与有机碳的比值（Cmic/Corg）降低；但土壤对Cu高强的结合容量导致该效应随时间而变得不显著；Biolog数据表明，在Cu的胁迫下，不仅微生物的群落结构有所改变，而且对碳源的优先利用种类发生了转移，碳源消耗量增加，消耗速度变快，同时这样的损伤效应具有长期性。

Relations between A-type granites and copper mineralization as exemplified by the Machangqing Cu deposit

This paper deals with the relations between the Machangqing rockbody which corresponds to the A-type granites and porphyry copper mineralization in terms of petrochemistry, trace element geochemistry, fluid inclusion geochemistry and isotope geochemistry. The results show that the Machangqing porphyry copper deposit was formed from the fluid predominated by mag-matic fluid. This kind of ore-forming fluid was just differentiated from the magma responsible for the A-type granites. therefore,as viewed from whereer they contain water or not,the A-type granites can,at least,be divided into two types: water-bearing and water-free.The water-bearing A-type granites can serve as the host ofporphyry copper deposits under certain geological conditions.