化学镀Ni-P合金的工艺条件研究

采用单因素试验法和正交试验法研究了还原荆以及化学镀时间、温度、pH值对化学镀沉积速度的影响,得到了一种稳定性好、镀速快的化学镀Ni—P合金的工艺.其最佳工艺条件为:NiSO4·6H2O30g/L,NaH2PO2·H2O40g/L,柠檬酸钠10g/L,醋酸9mL/L,乳酸9mL/L,pH值6.0,施镀温度90℃,施镀时间1.5h.该工艺条件下,镀速可达11.14mg/(cm2·h),化学镀1.5h后镀层厚度可达23.6-24.0μm.镀层具有较强的耐蚀性,孔隙率分布较窄.镀层表面平整、光亮、分布均匀,有可视性很好的淡黄色的光泽,无麻点、裂纹、起泡、分层或结瘤等缺馅.     

定期存款所含嵌入期权的定价

在Black-Scholes框架下,采用均值回复的Vasicek利率模型和偏微分方程的方法,用百慕大期权来近似,给出了定期存款的定价公式.     

矿床的体视化仿真技术与实现

为解决矿床仿真构模中对矿床几何信息描述和属性信息描述中存在的模型分离问题,采用体视化技术,建立了体矿床模型.通过分析矿床体视化仿真中的数据流程,建立了表现矿体空间分布、矿体中重点区域、矿体剖切分层的三类体模型,并实现了直接基于体模型的矿石储量、金属量的计算工作.经实例分析表明,利用体矿床建模技术,不仅能够进行矿床属性的定性分析,而且便于进行定量计算,为完善矿床建模技术提供了一条途径.     

Dating of sediment-hosted disseminated-type gold deposit by using ~(40)Ar/~(39)Ar laser probe: A case study of Changkeng large-scale gold deposit, China

Ore-forming age is one of the most important data in studying the genesis of mineral deposits. Dating of sedi-ment-hosted disseminated-type gold deposits, which areone of the most important types of gold deposits in theworld, is always a difficult task for ore geologists. Themajor reason is that most of the ores in this type deposit are of various siliceous and are composed of extremely fine-grained minerals, thus it will be very difficult to de-termine their ages by using conventional isotopi…     

Mineralizing age of the Rushan lode gold deposit in the Jiaodong Peninsula：SHRIMP U-Pb dating on hydrothermal zircon

Knowledge of the mineralizing timing is fundamen-tal to understand the genesis of mineral deposits, and ex-act time spectrum of mineralization is essential to com-prehending the relationship among the genesis of en-dogenic hydrothermal deposits, regional tectonic-magma-tism event and the geodynamics of mineral deposits. The Jiaodong or eastern Shandong gold province islocated in the southeastern margin of the North Chinacraton, and belongs to the Mesozoic circum-Pacific oro-genic gold system…     

Sm-Nd isotopic geochronology of the Yinachang Fe-Cu-REE deposit at Wuding, Yunnan Province and its genetic significance

Sm-Nd isotope systematics of ores and fluorites places precise time constraints on REE mineralization of the Yinachang Fe-Cu-REE deposit in Yunnan Province which occur in the Proterozoic Kunyan group. The ore-related fluorites contain high abundant REE, and show a strong enrichment of LREE and a positive Eu anomaly, which is in marked contrast to post-ore fluorites that are HREE enriched. The Sm-Nd isochron ages of the ores and fluorites are 1539±40 Ma and 1617±100 Ma, respectively, and calculated εNd（t） are -4.6 and -3.2. Accurate age determinations of the mineralization demonstrate that the REE mineralization took place during early Mesoproterozoic. Together with other geological evidence from the ore deposit, the primary REE-bearing ore-forming fluids are suggested to have been derived from the Enriched Mantle, and the Yinachang Fe-Cu-REE ore deposit is of volcanic exhalation- hydrothermal sedimentary origin. This study also imply that the sudden large-scale REE mineralization in the Mesoproterozoic epoch may have been induced by alkaline-rich anorogenic magmatism which occurred at marginal rifts of the continent in the Mesoproterozoic.     

新安江水库淤积分析研究

新安江水库位于浙江省钱塘江上游,控制流域面积10442平方公里。建库二十多年来,由于流域内植被受到破坏、相应水土流失加剧,导致水库淤积加速,严重影响到水库的寿命。本文通过对流域水土流失的调查、分析了入库泥沙量,对水库淤积速度、淤积方式和淤积部位进行了研究,并提出了减少水库淤积的几点建议。     

桂北九毛锡矿区岩浆岩含矿性及其成因探讨

根据对桂北九毛锡矿区岩浆岩野外地质、岩石学、岩石化学、微量元素及稀土元素地球化学等方面的工作,结合成矿大地构造背景,本文着重讨论了与该锡矿成矿有关的超基性岩和花岗岩的含矿性及成因。在本区基性—超基性岩形成过程中锡元素的分异聚集作用,为锡矿成矿奠定了物质基础。花岗岩的形成和演化为成矿带来了大量热流体及部分成矿元素。主要与超基性岩有关的九毛锡矿是一种新的锡矿类型。     

漳平洛阳钼矿床的地质特征和成因类型

本文研究了洛阳钼矿床的产出特征、物质组成和硫、铅同位素等，并从辉钼矿的多型、蚀变类型及空间分布和成矿温度几个方面探讨矿床和成矿母岩的成因。     

潮汐周期在潮坪沉积中的记录

选择平静天气泥质潮滩相对淤积期进行现场直接观测每个潮周期的沉积物特征。结果表明潮汐层偶的厚度变化与大小周期潮差旋回性变化密切相关。原始数据平滑后曲线更清晰地展示出大小潮周期，反映随机的非潮汐因素的影响可以通过地定的数学方法予以去除。现代潮坪观测表明潮汐沉积可以记录潮汐能量呈周期性变化的特性，因此，可通过研究保存较完整的潮汐韵律层的层偶组来提取古潮汐信息。但这种蕴含潮汐信息的韵律层可能只局限于一些基本不受风浪影响的沉积环境，而在长江三角洲开敞型泥质潮坪难以保存。