应用地震层析成象技术研究深部速度结构

罗马尼亚Ｖａｎｃｅａ地震区是大陆上发生与板块磁撞和削减有关的中深部地震活动的地区之一。本文介绍了应用地震层析成象方法研究该地区深部速度结构成果。在研究中使用了地方和区域地震所记录的４３３个浅源和中部地震的到时资料反演求解深至２００ｋｍ的三维速度结构,在走时和射线路径的计算中利用了有效的三维射线跟踪技术,在反演中采用ＬＳＱＲ算法,高分辨率的地震层析图象揭示了速度结构的广泛不均匀性,结果表明,地震层析     

A Possible Explanation of the O‘Connell Effect in Close Binary Stars

A theoretical model for explaining the O‘Connell effect of close binary stars is given based on the hypothesis that the circumstellar material of a binary system is captured by its components.The results inferred form the model suggest that late-type and /or short-period binaries can easily produce obvious O‘Connell effect and that the occurrence of O‘Connell effect has no relation with the type of binaries,These conclusions are in agreement with the observed results.The observed O‘Connell effects of six binary systems are examined by the model.For three W-subtype W UMa binaries(YY Eri,BX Per and SW Lac).the densities of the materials captured by the two components are assumed to be equal,and the calculated O‘Connell effect is found to be almost equal to the observed effect.For three A-subtype W UMa systems(CN And,FG Hya and AU Ser),the two densities are assumed to be different,and are calculated separately.The calculated O‘Connell effect turns out to agree better with the observed effect than that was formerly obtained.     

A search for decay of with tin-loaded liquid scintillator

A search for the neutrinoless double-beta decay of ¹²⁴Sn was carried out using the tin-loaded liquid scintillator for an active source-detector technique. Tin (32.6%) in weight was successfully loaded into the liquid scintillator, and light output was as high as 57% of the unloaded liquid scintillator. A tin-loaded liquid scintillator with 1.1 ℓ volume was installed at the 700 m underground laboratory in YangYang, and data were taken for 5285 h. No evidence for the 0νββ decay was found and a lower limit on the ¹²⁴Sn half-life was obtained to be 2.0×10¹⁹ year with 90% C.L. The new limit represents a significant improvement with respect to those previously available for ¹²⁴Sn.     

南岭西段沙坪钨矿区花岗岩独居石U-Pb定年及地质意义

沙坪白钨矿床位于南岭成矿带西段苗儿山岩体西北部,产于晚侵入次细粒二云母二长花岗岩岩株中,整个岩株全岩钨矿化。为精确厘定沙坪白钨矿床的成岩成矿时代,本文利用LA-ICP-MS对花岗岩中的独居石进行U-Pb定年,获得岩株成岩年龄为405.0±2.1 Ma,表明沙坪白钨矿床形成于加里东晚期。结合前人研究资料,本文认为苗儿山岩体西北部加里东期的钨多金属成矿作用发生在430~405 Ma之间,区域上经历了较高程度分异作用的加里东期花岗岩浆促成了钨的富集,为沙坪钨矿区晚侵入次的细粒二云母二长花岗岩钨的成矿作用提供了物源。苗儿山岩体北部有望在寻找加里东期钨多金属矿床方面取得进一步突破。     

吉林福安堡钨钼矿床的发现及意义

在吉林省的吉林地区中部和北部大面积森林覆盖区,分布着大面积华力西期、印支期花岗岩类,受传统成矿理论的束缚,这一地区成为有色金属矿产勘查的"处女地"。新一轮1∶20万化探扫面之后,相继开展了不同方法的地球化学异常查证工作,从中发现了很有前景的福安堡钨钼矿床。实践证明,在东北森林覆盖区化探找矿方法十分有效,而且可以尽可能减少地质勘查过程中对植被的破坏,对保护生态环境起到积极的作用。     

湘西钨锑金矿床成矿的特征性地质标志

湘西钨锑金矿床主要分布于雪峰隆起之前寒武系浅变质岩系中,不同元素（矿物）组合的金矿床具有一系列特征性的成矿地质标志。