脉钨矿床的多次成岩成矿作用

根据各期次岩体及其岩脉、矿脉间的穿截关系以及“两层矿化”等地质现象，结合有关稳定同位素、成岩与成矿演化关系等资料分析，表明伴随多期次花岗岩浆的侵入，相应地发育有多期次成矿作用，可概括出一个多次成岩与多次成矿的演化模式。多期次成矿作用的研究，不仅可以查明矿体分布和矿化富集的规律性，而且对指导大型矿床的寻找和评价有着重要的实际价值。

AN EXPLICIT CRITERION FOR ANALYSING TWOPHASE FLOW DENSITY WAVE INSTABILITY

Ⅰ. INTRODUCTIONThe appearance of liquid and gas two-phase flow density wave instability is harmful to the safety and operation of water cooled nuclear reactors, boilers, steam generators and chemical equipments. By now the ordinary methods in investigation are the time domain and frequency domain methods which solve the dynamic differential equations directly.