158 resultados para 316.8487
Resumo:
勉略宁地区位于秦岭造山带西端,是指由阳平关深大断裂与勉略缝合带所夹的三角形地块,是我国西北重要的铜金多金属成矿远景区,已发现多种类型的铜、铁、铅、锌、金和银等多金属矿床(点)多达上百处(李朝阳等,2000;任小华,2001),除金矿床为大-超大型外(煎茶岭和李家沟金矿床),铜金多金属矿床规模均不大(中-小型),该区最具代表性的铜厂铜金多金属矿床和东沟坝金银铅锌多金属矿床,其规模也仅为中型,可谓是铜金多金属矿床(点)星罗棋布,仅是"只见星星,不见月亮".长期来,在区域铜金多金属矿产勘查研究方面仍存在诸多问题和争议,许多被大家所看好的地段或含矿层位的进一步找矿却步履艰难,久攻不破,寻找大型一超大型铜金多金属矿床一直是该区地质研究工作的难题.
Resumo:
文章研究了我国一些铁锰矿床、铜矿床及铅锌硫化物矿床矿石及矿物中铟的含量变化特点,发现In在不同类型的铅、锌、铜、铁、锰等矿床中并不大量富集,在这些矿床中矿石平均ωIn大都低于10×10^-6;在锡石硫化物矿床和富含锡的铅锌多金属矿床中,矿石中ωIn平均可达80×10^-6以上,这类矿床中铟的工业储量可达数百吨甚至数千吨,80%以上的铟都富集在闪锌矿中。研究结果表明,铟的富集成矿具有矿床类型和矿物专属性,这种专属性对铟资源的寻找与利用具有重要意义.
Resumo:
The influence of laser-field parameters, such as intensity and pulse width, on the population of molecular excited state is investigated by using the time-dependent wavepacket method. For a two-state system in intense laser fields, the populations in the upper and lower states are given by the wavefunctions obtained by solving the Schrodinger equation through split-operator scheme. The calculation shows that both the laser intensity and the pulse width have a strong effect on the population in molecular excited state, and that as the common feature of light-matter interaction (LMI), the periodic changing of the population with the evolution time in each state can be interpreted by Rabi oscillation and area-theorem. The results illustrate that by controlling these two parameters, the needed population in excited state of interest can be obtained, which provides the foundation of light manipulation of molecular processes. (C) 2005 Elsevier B.V. All rights reserved.