Mineral Deposit Model of Cu–Fe–Au Skarn System in the Edongnan Region, Eastern China     

XIE Guiqing  MAO Jingwen  ZHU Qiaoqiao  HAN Yingxiao  LI Wei  DUAN Chao  YE Hui 《《地质学报》英文版》2020,94(6):1797-1807

Cu and Fe skarns are the world’s most abundant and largest skarn type deposits, especially in China, and Au-rich skarn deposits have received much attention in the past two decades and yet there are few papers focused on schematic mineral deposit models of Cu–Fe–Au skarn systems. Three types of Au-rich deposits are recognized in the Edongnan region, Middle–Lower Yangtze River metallogenic belt: ~140 Ma Cu–Au and Au–Cu skarn deposits and distal Au–Tl deposits; 137–148 Ma Cu–Fe; and 130–133 Ma Fe skarn deposits. The Cu–Fe skarn deposits have a greater contribution of mantle components than the Fe skarn deposits, and the hydrothermal fluids responsible for formation of the Fe skarn deposits involved a greater contribution from evaporitic sedimentary rocks compared to Cu–Fe skarn deposits. The carbonate-hosted Au–Tl deposits in the Edongnan region are interpreted as distal products of Cu–Au skarn mineralization. A new schematic mineral deposit model of the Cu–Fe–Au skarn system is proposed to illustrate the relationship between the Cu–Fe–Au skarn mineralization, the evaporitic sedimentary rocks, and distal Au–Tl deposits. This model has important implications for the exploration for carbonate–hosted Au–Tl deposits in the more distal parts of Cu–Au skarn systems, and Fe skarn deposits with the occurrence of gypsum-bearing host sedimentary rocks in the MLYRB, and possibly elsewhere.  相似文献   

Comparisons of Salinity Adaptation in Terms of Growth,Body Composition,and Energy Budget in Juveniles of Rainbow and Steelhead Trouts (Oncorhynchus mykiss)     

XIONG Yinghuai  WANG Xin  DONG Shuanglin  WANG Fang  YANG Jingwen  ZHOU Yangen 《中国海洋大学学报(英文版)》2019,(2)

This study examined the effect of different salinities(0, 5, 10, 15, 20, 25 and 30) on the growth performance and energy budget of juveniles of two different ecotypes of Oncorhynchus mykiss, landlocked rainbow trout and anadromous steelhead trout. In the 42 d experiment, fish were cultured in three replicate tanks per salinity treatment(eight fish per tank). At the end of the experiment, the growth of rainbow and steelhead trouts was significantly higher at salinities of 5 and 10, respectively, than at all other salinities. The protein, lipid and energy content of both ecotypes declined with the increase of salinity. Based on their energy budgets, the percentage of energy consumed for growth by rainbow and steelhead trouts were significantly higher at salinities of 5(34.00% ±1.69%) and 10(43.76% ± 1.29%), respectively, than at all other salinities. The percentage of energy consumed for respiration by rainbow and steelhead trouts was lower at salinities of 5(54.90% ± 1.77%) and 10(46.73% ± 0.62%), respectively, than at all other salinities. Our results indicated that the salinity adaptation ability of juvenile steelhead trout was slightly better than that of juvenile rainbow trout, and salinities of 10 and 5, respectively, were most suitable for growth of these two fishes.  相似文献   

基于MINA框架的应急救助与地震灾情管理平台设计与实现     

肖本夫  申源  陈维锋  毛利  格桑扎西  梁厚朗 《震灾防御技术》2020,15(4):836-845

针对不同用户群体应急救助和地震灾情需求，基于MINA框架，运用阿里云基础架构、微信组件和应用程序接口等技术方法，设计并构建集灾情信息收集与报送、应急救助服务、科普宣教等功能于一体的管理平台。该平台的设计与实现不仅有利于震后现场应急队员收集并准确报送实时灾情信息，还可为被救助人员提供防震减灾知识和地震应急避难场所空间分布等应急救助信息，实现了应急救助与地震灾情的综合管理，提升了震后应急救助、应急指挥和辅助决策等方面的服务能力。  相似文献   

A natural language processing and geospatial clustering framework for harvesting local place names from geotagged housing advertisements     

Yingjie Hu  Huina Mao  Grant McKenzie 《International journal of geographical information science》2019,33(4):714-738

Local place names are frequently used by residents living in a geographic region. Such place names may not be recorded in existing gazetteers, due to their vernacular nature, relative insignificance to a gazetteer covering a large area (e.g. the entire world), recent establishment (e.g. the name of a newly-opened shopping center) or other reasons. While not always recorded, local place names play important roles in many applications, from supporting public participation in urban planning to locating victims in disaster response. In this paper, we propose a computational framework for harvesting local place names from geotagged housing advertisements. We make use of those advertisements posted on local-oriented websites, such as Craigslist, where local place names are often mentioned. The proposed framework consists of two stages: natural language processing (NLP) and geospatial clustering. The NLP stage examines the textual content of housing advertisements and extracts place name candidates. The geospatial stage focuses on the coordinates associated with the extracted place name candidates and performs multiscale geospatial clustering to filter out the non-place names. We evaluate our framework by comparing its performance with those of six baselines. We also compare our result with four existing gazetteers to demonstrate the not-yet-recorded local place names discovered by our framework.  相似文献   

张家口蔚县农村房屋抗震性能调查及统计分析     

马旭东  牛露  刘晓丹  刘龙  茅远哲  关恒瑜  刘贾贾  刘志辉 《震灾防御技术》2019,14(4):829-837

为进一步了解蔚县地区农村房屋的抗震性能，在该地区选取43个村庄、7732栋房屋进行实地调查和统计分析。主要调查房屋结构、建筑材料、房屋抗震构造措施等内容，分析各结构类型房屋抗震薄弱环节及房屋抗震性能，并统计分析经济、交通、地形等因素与房屋结构类型及抗震性能的关系，提出提高该地区农村房屋抗震性能的建议。  相似文献   

印度尼西亚北苏拉威西蓝碧海峡浮游动物种类组成及分布   总被引：1，自引：0，他引：1  

王彦国  陈小银  邢炳鹏  孙柔鑫  FITRIA Nurul  项鹏  王春光  林茂 《海洋学报(英文版)》2018,37(12):35-44

Based on oceanographic survey data in June 2012 in the Lembeh Strait, the zooplankton ecological characteristics such as species composition, individual abundance, dominant species and distribution were analyzed. The results showed that 183 species(including 4 sp.) had been recognized, most of them belonged to copepoda.Cnidaria followed with 43 species(including 1 sp.) were identified. The average abundance of zooplankton was(150.47±58.91) ind./m~3. As to the horizontal distribution, the abundance of the zooplankton was higher in the southern waters than in the northern waters. The dominant species in the study area were Lensia subtiloides,Sagitta enflata, Lucifer intermedius, Oikopleura rufescens, Diphyes chamissoni, Creseis acicula, Subeucalanus subcrassus, Temora discaudata, Aglaura hemistoma, Doliolum denticulatum, Canthocalanus pauper, Oikopleura longicauda and Nanomia bijuga. Zooplankton biodiversity indexes were higher in study area than previous study in the other regions. The findings from this study provide important baseline information for future research and monitoring programs.  相似文献   

Exploring Spatially Non-stationary Relationships in the Determinants of Mineralization in 3D Geological Space     

Huang  Jixian  Mao  Xiancheng  Chen  Jin  Deng  Hao  Dick  Jeffrey M.  Liu  Zhankun 《Natural Resources Research》2020,29(1):439-458

Exploring the spatial relationships between various geological features and mineralization is not only conducive to understanding the genesis of ore deposits but can also help to guide mineral exploration by providing predictive mineral maps. However, most current methods assume spatially constant determinants of mineralization and therefore have limited applicability to detecting possible spatially non-stationary relationships between the geological features and the mineralization. In this paper, the spatial variation between the distribution of mineralization and its determining factors is described for a case study in the Dingjiashan Pb–Zn deposit, China. A local regression modeling technique, geological weighted regression (GWR), was leveraged to study the spatial non-stationarity in the 3D geological space. First, ordinary least-squares (OLS) regression was applied, the redundancy and significance of the controlling factors were tested, and the spatial dependency in Zn and Pb ore grade measurements was confirmed. Second, GWR models with different kernel functions in 3D space were applied, and their results were compared to the OLS model. The results show a superior performance of GWR compared with OLS and a significant spatial non-stationarity in the determinants of ore grade. Third, a non-stationarity test was performed. The stationarity index and the Monte Carlo stationarity test demonstrate the non-stationarity of all the variables throughout the area. Finally, the influences of the degree of non-stationary of all controlling factors on mineralization are discussed. The existence of significant non-stationarity of mineral ore determinants in 3D space opens up an exciting avenue for research into the prediction of underground ore bodies.

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等面积纬度和等量纬度间的直接变换     

李松林  李厚朴  边少锋  宗敬文 《海洋测绘》2019,39(3):26-30

为了便于实现等面积方位投影与椭球等角圆柱或圆锥投影之间的变换,借助具有强大符号运算功能的计算机代数系统Mathematica,推导出了等面积纬度和等量纬度之间变换的直接表达式,进一步将表达式改进为适合电算的形式,并将其系数统一表示为关于椭球偏心率e和椭球第三扁率n的幂级数形式。通过算例分析表明:基于第三扁率n的幂级数表达式具有更紧凑的形式和更好的收敛性,且导出公式的计算误差分别小于10~(-8)和10~(-8)″,可以满足大地测量和地图制图计算精度要求。  相似文献   

Scattering pattern analysis and true-amplitude generalized Radon transform migration for acoustic transversely isotropic media with a vertical axis of symmetry     

Quan Liang  Wei Ouyang  Weijian Mao  Shijun Cheng 《Geophysical Prospecting》2020,68(4):1211-1227

In multi-parameter ray-based anisotropic migration/inversion, it is essential that we have an understanding of the scattering mechanism corresponding to parameter perturbations. Because the complex nonlinearity in the anisotropic inversion problem is intractable, the construction of true-amplitude linearized migration/inversion procedures is needed and important. By using the acoustic medium assumption for transversely isotropic media with a vertical axis of symmetry and representing the anisotropy with P-wave normal moveout velocity, Thomsen parameter δ and anelliptic parameter η, we formalize the linearized inverse scattering problem for three-dimensional pseudo-acoustic equations. Deploying the single-scattering approximation and an elliptically anisotropic background introduces a new linear integral operator that connects the discontinuous perturbation parameters with the multi-shot/multi-offset P-wave scattered data. We further apply the high-frequency asymptotic Green's function and its derivatives to the integral operator, and then the scattering pattern of each perturbation parameter can be explicitly presented. By naturally establishing a connection to generalized Radon transform, the pseudo-inverse of the integral operator can be solved by the generalized Radon transform inversion. In consideration of the structure of this pseudo-inverse operator, the computational implementation is done pointwise by shooting a fan of rays from the target imaging area towards the acquisition system. Results from two-dimensional numerical tests show amplitude-preserving images with high quality.  相似文献   

Response of A Gravel - Bed River To Dam Closure: Insights From Sediment Transport Processes And Channel Morphodynamics     

A. Brenna  N. Surian  L. Mao 《地球表面变化过程与地形》2020,45(3):756-770

This work deals with the impacts of dams on large gravel -bed rivers in terms of altering coarse transport regimes and the relationship with river morphodynamics. Using data collected by a tracer -based monitoring programme carried out in a 4 -km -long study sector of the Parma River (Italy), located downstream from a relatively recently established dam, we applied a virtual velocity approach to estimate the coarse bed material load at four river cross -sections. Monitoring and calculation results provided new insights into the impacts of the dam on streambed material mobility and the sediment regime over the 17 -month calculation period. A longitudinal gradient of effects was observed along the study sector. Sections located closer to the dam are characterized by more evident impacts due to deficits in coarse sediment input from upstream. Sediment mobility here is strongly altered, especially in the highly armoured main channel, and the overall bed material load is extremely low. A partial recovery of sediment dynamics was observed at the sections located further from the dam, where estimates indicate higher sediment yield. The observed longitudinal trend in the coarse sediment transport regime matches the morphology, as the river shifts downstream from a sinuous configuration with alternate bars to a wandering one. The novel insights into alteration of coarse sediment dynamics and the relationship with river morphodynamics are potentially applicable to many other fluvial contexts affected by similar impoundments. © 2019 John Wiley & Sons, Ltd.  相似文献