磷灰石对铀的吸附实验及其对相山矿田铀成矿意义探讨     

王倩  胡宝群  牛建国  宋金如  邱林飞 《地质论评》2016,62(S1):337-338

相山铀矿田是典型的火山岩型热液铀矿田,在矿田内赋存的铀矿物主要有沥青铀矿、钛铀矿、铀钍石等,大量的水云母、磷灰石、赤铁矿、绿泥石、金红石、微晶石英等矿物与铀矿物密切共生。这些共生矿物的共同特征之一为颗粒细小,呈纳米级,非晶质,胶体性质显著。铀矿物大量分布于这些胶态共生矿物的表面和裂隙中（胡宝群,2011;王倩,2016）。可知,吸附作用是导致铀富集沉淀的重要机理之一。本文以磷灰石为例,通过宏观地质特征研究及实验模拟,探讨pH、温度、热液共存组分、时间等物理化学条件对磷灰石吸附铀的制约,进而探讨磷灰石的吸附性能对富大铀矿床形成的意义。  相似文献   

上扬子会泽地区早三叠世飞仙关组砂岩物源特征:来自重矿物铬尖晶石和碎屑锆石的限定   总被引：1，自引：0，他引：1  

张英利  王宗起  王刚  李谦  林健飞 《地质论评》2016,62(1):54-72

上扬子会泽地区早三叠世飞仙关组主要为河流相的紫红色砂岩,物源主要来自于西部和西北部。碎屑重矿物组合表明物源主要来自于岩浆岩,且重矿物中发现大量碎屑铬尖晶石和锆石。本文运用电子探针微区成分分析和碎屑锆石U-Pb测年方法,对上扬子早三叠世飞仙关组砂岩中铬尖晶石和碎屑锆石进行分析。铬尖晶石电子探针化学成分分析显示,其具有高铬、低Fe~(3+)和高TiO_2含量的特征,源岩分析指示这些铬尖晶石来源于与洋岛/板内、岛弧以及大火成岩省相关的火成岩。同时,碎屑锆石LA-ICP-MS U-Pb年龄测定表明,飞仙关组的物源主要来自于248~272Ma和715~997Ma的岩浆岩。铬尖晶石和碎屑锆石综合分析表明,248~272Ma的物源岩石具有大火成岩省玄武岩特征,主要为峨眉山玄武岩及同期基性侵入岩;715~997M的物源为洋岛/板内玄武岩类,主要为研究区周缘与新元古代苏雄组及其同期的岩浆岩;铬尖晶石指示的岛弧性质物源则可能源自1000~1100Ma的岩浆岩。同时,碎屑锆石还指示古元古代和早寒武世发育岩浆作用,且存在古老的新太古代结晶基底。这些资料为上扬子地区构造演化提供了沉积学的证据。  相似文献   

Upper-Tropospheric Environment–Tropical Cyclone Interactions over the Western North Pacific: A Statistical Study     

Yu-Kun QIAN  Chang-Xia LIANG  Zhuojian YUAN  Shiqiu PENG  Junjie WU  Sihua WANG 《大气科学进展》2016,33(5):614-631

Based on 25-year(1987–2011) tropical cyclone(TC) best track data, a statistical study was carried out to investigate the basic features of upper-tropospheric TC–environment interactions over the western North Pacific. Interaction was defined as the absolute value of eddy momentum flux convergence(EFC) exceeding 10 m s~(-1)d~(-1). Based on this definition, it was found that 18% of all six-hourly TC samples experienced interaction. Extreme interaction cases showed that EFC can reach~120 m s~(-1)d~(-1) during the extratropical-cyclone(EC) stage, an order of magnitude larger than reported in previous studies.Composite analysis showed that positive interactions are characterized by a double-jet flow pattern, rather than the traditional trough pattern, because it is the jets that bring in large EFC from the upper-level environment to the TC center. The role of the outflow jet is also enhanced by relatively low inertial stability, as compared to the inflow jet. Among several environmental factors, it was found that extremely large EFC is usually accompanied by high inertial stability, low SST and strong vertical wind shear(VWS). Thus, the positive effect of EFC is cancelled by their negative effects. Only those samples during the EC stage, whose intensities were less dependent on VWS and the underlying SST, could survive in extremely large EFC environments, or even re-intensify. For classical TCs(not in the EC stage), it was found that environments with a moderate EFC value generally below ~25 m s~(-1)d~(-1) are more favorable for a TC's intensification than those with extremely large EFC.  相似文献   

Mesoscale numerical simulation study of warm fog dissipation by salt particles seeding     

Hui He  Xueliang Guo  Xiang’e Liu  Qian Gao  Xingcan Jia 《大气科学进展》2016,33(5):579-592

Based on the dynamic framework of WRF and Morrison 2-moment explicit cloud scheme, a salt-seeding scheme was developed and used to simulate the dissipation of a warm fog event during 6–7 November 2009 in the Beijing and Tianjin area. The seeding effect and its physical mechanism were studied. The results indicate that when seeding fog with salt particles sized 80 μm and at a quantity of 6 gm~(-2) at the fog top, the seeding effect near the ground surface layer is negative in the beginning period, and then a positive seeding effect begins to appear at 18 min, with the best effect appearing at 21 min after seeding operation. The positive effect can last about 35 min. The microphysical mechanism of the warm fog dissipation is because of the evaporation due to the water vapor condensation on the salt particles and coalescence with salt particles.The process of fog water coalescence with salt particles contributed mostly to this warm fog dissipation. Furthermore, two series of sensitivity experiments were performed to study the seeding effect under different seeding amounts and salt particles sizes. The results show that seeding fog with salt particles sized of 80 μm can have the best seeding effect, and the seeding effect is negative when the salt particle size is less than 10 μm. For salt particles sized 80 μm, the best seeding effect, with corresponding visibility of 380 m, can be achieved when the seeding amount is 30 g m~(-2).  相似文献   

Characteristics of the Asian–Pacific Oscillation in Boreal Summer Simulated by BCC_CSM with Different Horizontal Resolutions     

Yazhou Zhang  Zhijie Liao  Yaocun Zhang  Feng Nie 《大气科学进展》2016,33(12):1401-1412

The summer Asian–Pacific Oscillation(APO) is a major teleconnection pattern that reflects the zonal thermal contrast between East Asia and the North Pacific in the upper troposphere. The performance of Beijing Climate Center Climate System Models(BCC CSMs) with different horizontal resolutions, i.e., BCC CSM1.1 and BCC CSM1.1(m), in reproducing APO interannual variability, APO-related precipitation anomalies, and associated atmospheric circulation anomalies, is evaluated.The results show that BCC CSM1.1(m) can successfully capture the interannual variability of the summer APO index. It is also more capable in reproducing the APO's spatial pattern, compared to BCC CSM1.1, due to its higher horizontal resolution. Associated with a positive APO index, the northward-shifted and intensified South Asian high, strengthened extratropical westerly jet, and tropical easterly jet in the upper troposphere, as well as the southwesterly monsoonal flow over North Africa and the Indian Ocean in the lower troposphere, are realistically represented by BCC CSM1.1(m), leading to an improvement in reproducing the increased precipitation over tropical North Africa, South Asia, and East Asia, as well as the decreased precipitation over subtropical North Africa, Japan, and North America. In contrast, these features are less consistent with observations when simulated by BCC CSM1.1. Regression analysis further indicates that surface temperature anomalies over the North Pacific and the southern and western flanks of the Tibetan Plateau are reasonably reproduced by BCC CSM1.1(m), which contributes to the substantial improvement in the simulation of the characteristics of summer APO compared to that of BCC CSM1.1.  相似文献   

The global monsoon division combining the k-means clustering method and low-level cross-equatorial flow     

Ning Jiang  Weihong Qian  Jeremy Cheuk-Hin Leung 《Climate Dynamics》2016,47(7-8):2345-2359

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基于外弹道计算的人影高炮作业安全评估方法     

黎祖贤  刘红武  廖俊  张中波  周盛 《气象科技》2016,44(1):152-156

随着经济的高速发展,各个高炮作业点所在地的周边环境已经发生了很大变化,为了进一步提高人工影响天气作业的安全性,针对高炮作业特点提出了一套安全论证方法。推导了弹道计算的方法,在此基础上结合安全射界法和地理信息系统对作业安全性进行了更精确的评估,并给出实例说明。提出用危险系数的方法进行安全性评估,给出了具体的危险系数定义方法,通过评估系统的一次实际作业评估证明了危险系数进行安全性评估的可行性。以该方法进行安全性评估可有效保障人影作业的安全性,为人影作业提供重要的参考。  相似文献   

FDR自动土壤水分数据标定问题及解决方法   总被引：4，自引：0，他引：4  

周旭辉  王黎明  王建波  陈晨  王爱珍  刘焕乾  廖华 《气象科技》2016,44(4):535-541

针对目前FDR自动土壤水分数据可用性低的实际情况,本文从FDR自动土壤水分站传感器原理出发,结合数据处理流程与方法对湖南60个站点不同层次的标定参数及部分站点的相关观测数据进行了分析,指出目前田间标定法在自然条件下几乎无法得到覆盖土壤各个湿度区间的均匀样本数据,导致二次标定参数不合理是造成FDR自动土壤水分站数据可用性差的根本原因。二次标定方程参数不合理主要表现为方程斜率过大、过小、负值3种情况,导致观测数据增幅过大、常年不变、与实际土壤湿度变化趋势完全相反等问题。最后针对该问题提出了大样本原状取土,实验室标定的解决方法,并对方法进行了初步验证,结果表明该方法能从源头上有效改善土壤水分站观测数据质量。  相似文献   

风云卫星数据服务评价指标的验证分析     

李雪  咸迪  亓永刚  徐喆  钱建梅 《气象科技》2016,44(4):692-696

简述了目前我国风云卫星数据服务以及气象服务效益评估业务的现状,利用层次分析法提出风云卫星数据服务评价的6个1级指标和19个2级指标。设计了风云卫星数据服务评测量表,并采用分半信度、因子分析等方法对量表作信度和效度分析,结果表明所设计的评测量表具有良好的信度和效度,确定了包括服务平台易用性、服务流程规范性、服务响应及时性、服务内容完整性、服务工作主动性、服务宣传广泛性等6个方面的风云卫星数据服务评价指标。  相似文献   

板桥-合水地区长6₃储层成岩相孔隙结构特征及优质储层分布     

张茜  孙卫  明红霞  王倩  张龙龙 《沉积学报》2016,34(2):336-345

利用铸体薄片、扫描电镜、常规压汞、恒速压汞及相渗等资料,研究了板桥-合水地区长6₃储层成岩相类型及其微观孔隙结构特征,总结了不同成岩相的测井响应特征,确定了纵向及平面分布规律。结果表明优质成岩相的展布受沉积相、成岩作用与孔隙结构共同控制,尤其是喉道分布才是控制砂岩储层渗透性的主要因素。水云母胶结-残余粒间孔相和水云母胶结-长石溶蚀相储层主要分布于半深湖相重力流复合水道浊流沉积中,细-微细喉道发育,孔喉连通性好,渗流能力最好,油水呈相对均匀的渗流,孔隙内的油气极易通过喉道被开采出来;绿泥石胶结相、水云母胶结弱溶蚀相储层位于分支水道边缘,呈孤岛状分布,孔喉半径小但分布均匀,渗流能力中等-差;碳酸盐胶结相、碳酸盐+水云母胶结相储层主要发育在分支水道间,孔隙结构发育程度差,喉道细小且孔喉连通性差,富集于孔隙中的油气难以通过小喉道,采收率低。  相似文献