甘肃两当县大店沟金矿地质特征及找矿标志     

吴金刚  张圆  杨绍虎 《矿产与地质》2015,(2):163-167

研究区属北秦岭金多金属成矿带,大店沟金矿床位于李子园-湘潭子新元古―晚古生代陆源裂陷火山-碎屑沉积岩带中,控矿因素主要有地层、构造。奥陶―震旦系李子园群是金矿床的赋矿层位,矿床分布受区域性元家坪―小寺沟韧性剪切带控制,NE向次级的韧性剪切带是重要的控矿构造,矿床类型为构造蚀变岩型。通过对本矿床成矿地质条件、控矿因素、矿化富集规律研究,总结了北秦岭地区地层、构造、岩体、围岩蚀变、地球化学异常等找矿标志,提出了该地区金矿勘查思路及找矿方向。  相似文献   

中国九龙江河口营养盐基准值研究     

刘保莉  曹文志  黄铮  陈文慧  陈辉煌  刘录三 《海洋学报(英文版)》2018,37(2):1-13

One of the key concerns in estuarine and coastal environments is eutrophication, which is known to be closely connected to nutrient enrichment. To control and improve surface water quality, nutrient criteria are recommended in order to provide reference conditions for the environment. However, the current datasets of nutrient criteria in China are either designed for surface water or sea water, and as such these are not suitable for assessing estuarine water quality, especially given the unique ecosystem and dynamic properties of estuaries. To address this issue in current estuarine water management, nutrient criteria have been developed for a local estuary in the southeast of China. Segmentation of the Jiulong River Estuary, China was firstly analysed through field investigations carried out during 2013–2014, which resulted in the delineation of three segments characterized by their distinct properties in relation to salinity, hydrology, ecosystems, etc. Historical records from 1997 to 2014 were then analysed using statistical modelling to develop candidate nutrient criteria for the estuary.This stage of the analysis was undertaken in combination with the study of nutrient status records from the 1980s,which were used to establish a baseline reference condition. The recommended criteria values of dissolved inorganic nitrogen(DIN) in Segments Ⅰ, Ⅱ and Ⅲ of the Jiulong River Estuary are 64, 21 and 14 μmol/L,respectively, and the corresponding values for soluble reactive phosphorus(SRP) are 0.89, 0.76 and 0.89 μmol/L,respectively. It should be emphasised that these values are site-dependent, and that different results may be achieved at other locations depending on the physical and biogeochemical characteristics of an estuary, or even a single site within a catchment. It is hoped that by demonstrating a possible methodological approach and methods of nutrient criteria derivation in the Jiulong River Estuary, the current study will offer researchers some fundamental basis from which to begin to develop more complete nutrient criteria indices for the study of nutrient conditions in other estuaries throughout China.  相似文献   

中国还原性斑岩矿床研究进展及判别标志   总被引：1，自引：1，他引：0  

申萍  潘鸿迪 《岩石学报》2020,36(4):967-994

世界上大多数斑岩矿床的成矿流体为氧化流体(CO_2 CH_4)。然而,Rowins(2000)提出一些斑岩Cu-Au矿床的成矿流体为富含CH_4的还原流体,矿床缺乏磁铁矿、赤铁矿和硬石膏等表征高氧逸度的矿物,而发育大量的磁黄铁矿,矿床规模小,矿床形成与含钛铁矿的还原性的Ⅰ型花岗岩类有关,并将其称之为还原性斑岩Cu-Au矿床。我国学者研究发现,中国不但发育还原性斑岩铜矿床,还发育还原性斑岩-矽卡岩铜矿床和还原性斑岩钼矿床,我们建议将这三种矿床统称为还原性斑岩矿床。本文基于课题组近十年来的研究工作,并结合前人的研究成果,综合分析了中国发育的大中型还原性斑岩矿床的典型实例,在此基础上,重点阐明中国大型还原性斑岩矿床的特点、流体中CH_4来源及其有关的成矿作用、容矿围岩特点、成矿岩浆氧化还原状态及其成因、矿床形成的构造背景等。与Rowins(2000)提出的还原性斑岩铜矿床规模小的特点不同,中国发育的一些还原性斑岩矿床规模大;我们研究还识别出该类矿床发育独特的热液矿物和矿石矿物,比如,还原性斑岩铜矿发育热液钛铁矿,矿石矿物以黄铜矿为主,罕见斑铜矿、辉铜矿等矿物;还原性斑岩钼矿床出现热液钛铁矿,矿石矿物以辉钼矿为主,罕见黑钨矿和锡石等矿物;还原性斑岩-矽卡岩铜矿床的矽卡岩期发育钙铝榴石、钙铁辉石等还原性矽卡岩矿物和大量的磁黄铁矿,热液期以发育黄铜矿而非斑铜矿和辉铜矿等矿石矿物为特征。因此,还原性斑岩矿床除了Rowins(2000)提出的发育富CH_4还原流体和磁黄铁矿等识别标志之外,还可辅以独特的脉石矿物(如钛铁矿、钙铝榴石、钙铁辉石等)和简单的矿石矿物(如黄铜矿、辉钼矿等)这两个标志进行识别。中国还原性斑岩矿床含矿岩体的围岩中普遍发育还原性岩石(如含碳质沉积岩或火山沉积岩、含亚铁的火山岩或火山沉积岩等);对于成矿流体中CH_4、C_2H_6等还原性气体的来源,多数学者认为CH_4、C_2H_6等还原性气体主要源于还原性围岩,部分源于岩浆。关于还原性斑岩矿床的成矿岩体是否为含钛铁矿的、还原性的花岗岩类,目前研究较少且存在争议,多数学者认为成矿原始岩浆为氧化性岩浆,但其氧逸度偏低,少数学者认为成矿岩浆始终为还原岩浆。还原性斑岩矿床与经典的斑岩矿床的成矿构造背景类似,二者没有明显区别。还原性斑岩矿床显示的还原性热液蚀变和成矿特点均与成矿流体富含CH_4还原气体密切相关,因此,富含CH_4还原流体是还原性斑岩矿床形成的关键。  相似文献   

Evaluation System for Yunnan Cultural Tourism Routes Based on a Five Component Model: Case Study of the Ancient Tea-horse Road in the South of Yunnan     

WANG Yan  XIE Hongzhong  ZHU Tao 《资源与生态学报(英文版)》2019,10(5):553-558

Cultural tourism routes can reveal and protect cultural tourism heritage by means of cultural tourism in the “time category” and the “space category”. The construction of an evaluation system for cultural tourism routes and the evaluation, scoring and grading of existing and potential cultural tourism routes are the key to the protection of heritage, history and culture along these routes, and the key to encouraging the standardization, branding and sustainable development of various formats on the routes. Yunnan cultural tourism routes are diverse and rich in resources, and their developmental foundation is good. However, the tourism development and cultural development activities occur along separate lines and there is a lack of unified management. Therefore, it is necessary to conduct research on information collection, information analysis, problem diagnosis and improvement of status in the local practices of Yunnan cultural tourism routes, and to guide the sustainable development of Yunnan cultural tourism routes. Based on the advanced experience of COE (Council of Europe), UNESCO WHC (United Nations Educational, Scientific and Cultural Organization, World Heritage Committee) and ICOMOS(International Council on Monuments and Sites), this paper comprehensively analyzes the decisive criteria for line evaluation by interpreting and summarizing the connotations of cultural tourism routes, and determines that the evaluation of cultural tourism routes should include lines. Five aspects―the theme, the participating subject, the object itself, related activities and multi-party value―are used to construct a five-component model. At the same time, based on the consumer utility function, a complete route evaluation and hierarchical system is constructed. Then, taking the Ancient Tea-horse Road cultural tourism route as an example and using the expert scoring method and the analytic hierarchy process, the actual scores and grades of the Ancient Tea-horse Road cultural tourism route are determined, and countermeasures and suggestions for its sustainable development are proposed. The paper also verifies the applicability and practicability of the evaluation system, and promotes and improves the feedback evaluation system. The aim is to at promote and widely apply the evaluation system of cultural tourism routes, realizing the transformation from individual cases to joint cases, and promoting the standardization and sustainable development of cultural tourism routes.  相似文献   

吉林省集安市马蹄沟晶质石墨矿地质特征及找矿标志     

李先先  沈济篷  赵久悦 《吉林地质》2020,39(1):66-68,78

吉林省集安市马蹄沟晶质石墨矿位于吉林省集安市财源乡马蹄沟一带,文章对该矿床地层、构造、岩浆岩等地质特征及矿床成因进行研究,认为赋存于古元古界集安群荒岔沟组的晶质石墨与硼铁建造、含磷透辉石建造、铀-稀土建造等相应矿床均属于海底火山喷发沉积变质、岩浆热液作用的层控矿床,马蹄沟晶质石墨矿成因类型为沉积变质型晶质石墨矿床。总结该地区晶质石墨矿的找矿标志。  相似文献   

An approach to model the mechanical behavior of transversely isotropic materials          下载免费PDF全文

M. Mahjoub  A. Rouabhi  M. Tijani  S. Granet 《国际地质力学数值与分析法杂志》2016,40(6):942-961

The present work proposes an approach to adapt existing isotropic models to transversely isotropic materials. The main idea is to introduce equivalence relations between the real material and a fictitious isotropic one on which one can take all the advantages of the well‐established isotropic theory. Two applications of this approach are presented here: a failure criterion and a damage model that takes into account the load‐induced anisotropy. In both cases, theoretical predictions are in agreement with the experimental data. In the present paper, the developed approach is applied to sedimentary rock materials; nevertheless, it can be generalized to any material that exhibits transverse isotropy. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

基于改进混合蛙跳算法的个性化旅游路线推荐     

申晓宁  王森林  吴俊潮  仇友辉  张磊  李常峰  王玉芳 《南京气象学院学报》2021,13(4):467-476

大众在旅游途中期望获得开销低、行程方便、舒适度高的旅游体验,同时还具有历史人文、自然景观、美食购物等不同游览需求.因此,本文提出了一种基于改进混合蛙跳算法的个性化旅游路线推荐方法.首先建立个性化旅游路线推荐问题的优化模型,并针对该模型的特点,设计改进混合蛙跳算法.通过调整可控精度,增加筛选准则和及时处理异常解等策略增强群体的多样性,降低遗漏最优解的风险,强化局部搜索能力,并提高算法的求解精度.以南京三日游个性化旅游路线推荐问题作为实例,收集南京市内知名景点的门票价格、开放时间、不同出行方式所需的时间和花费情况以及食宿费用等相关数据,基于改进混合蛙跳算法进行求解.实验结果表明,与改进前的方法相比,所提改进方法能够获取更优的路径解,推荐的路线能够更好地满足用户的个性需求.  相似文献   

Structural modeling and testing of a concrete canoe     

F. Paradis  G. Gendron 《Ocean Engineering》2007,34(1):206-217

A finite element model is set up and experimental tests are performed to help understand the behavior of a concrete canoe and subsequently optimize its design. First, the performance criteria that must be satisfied to participate at the annual ASCE/Master Builders competition are described. Then, the finite element model and the different loading cases that were studied are presented. Results from these loading cases are discussed and used to optimize the material properties as well as the thickness of the hull and the dimensions of the gunwale and reinforcing ribs. Static and dynamic experimental tests were also conducted to validate the results of the finite element analyses. The results indicate that the main stresses and strains are caused by the static load cases. The additional stresses caused during races are small.  相似文献   

ENVISAT-1卫星测高数据编辑标准的研究   总被引：2，自引：0，他引：2  

赵小阳  李建成  金涛勇  褚永海 《海洋测绘》2006,26(6):65-67

介绍了环境卫星(ENVISAT-1)的基本情况及其主要技术参数,在借鉴其他卫星测高数据编辑标准和大量统计基础上,制定了ENVISAT-1卫星的数据编辑标准,包括冰标志和S波段异常的确定,并给出了各改正项合理的限值。  相似文献   

An evaluation of systems for the integrated assessment of capture fisheries     

Duncan Leadbitter  Trevor J. Ward 《Marine Policy》2007

Integrated fishery assessments are intended to take an integrated and wholistic view of fisheries management, to provide comprehensive systems-based evaluations of the sustainability of individual fisheries and their products. Using guidance derived from decision theory and management science, we develop 18 criteria to evaluate the likely effectiveness of nine integrated fishery assessment systems. The assessment systems do not consistently consider four key criteria: the socio-economic impacts of fisheries, the provision of food security, the local relevance of the assessment to the fishery under assessment, and the independent peer review of assessment outcomes. Other important areas of weakness include the lack of appropriate consultation processes relating to both the design of the assessment system and the outcomes of fishery assessments, and limitations in the quality of data and information used in assessments. Improvements will be needed in these areas across all the systems we evaluated if fishers, consumers, managers and other stakeholders are to be provided with consistently reliable assessment outcomes, and an assurance of the sustainability of capture fisheries.  相似文献