中国三地软玉的矿物组成和成矿地质背景研究     

韩磊  洪汉烈 《地质科学译丛》2009,(3):6-10

为了查明新疆玛纳斯、青海格尔木、江苏溧阳产软玉的矿物组成和了解其品质与矿物组成的内在联系,为软玉的鉴别与质量评价等提供基础资料,采用偏光显微镜、电子探针、X射线粉末衍射等测试方法对3个产地的软玉样品进行了测试分析,从矿物成因特征、结构构造、矿物组成、化学成分等方面进行了对比分析。结果表明,新疆玛纳斯、青海格尔木、江苏溧阳的软玉虽然均由透闪石组成,但其晶体中Mg与Fe的离子数量明显不同,玛纳斯碧玉中的透闪石含有更多的Fe,其化学成分十分接近阳起石的;玛纳斯碧玉的成矿地质背景与格尔木和溧阳的有所差别,形成于蛇纹石化超镁铁岩中,富含FeOT和MgO,而溧阳和格尔木软玉则产于中酸性火成岩与白云质大理岩的接触带中,其FeOT的质量分数较低。软玉的颜色、韧性和透明度主要取决于其形成的地质背景条件。  相似文献   

Halosaurus pectoralis McCulloch (Pisces: Halosauridae) in the New Zealand region (note)     

D. G. McKnight 《新西兰海洋与淡水研究杂志》2013,47(3):555-556

Halosaurus pectoralis McCulloch is recorded from off Gisborne, New Zealand, and from south‐east of Lord Howe Island, thus adding a second species of the order Heteromi to the New Zealand fauna.  相似文献   

Harveys and Walking Maps     

《The Cartographic journal》2013,50(1):73-80

Abstract

Geographical information is connected to everyday life in many ways. Web cartography has made geospatial data more available to the public. In the next few years, the average age of the population will be over 51 years, with more than 15% of the population over the age of 65 years. The fact that the senior population is increasing suggests that online mapping and map viewer design should be aware of the senior population’s visual restrictions, as well as restrictions of other potential map users, including colour-vision-impaired users. This paper describes the senior population’s visual restrictions that can be compared with colour-vision-impaired users and provides guidelines with regard to online mapping and map viewer design for this growing segment of the elderly population.  相似文献   

An Empirical User Study for Measuring the Influence of Colour Distance and Font Size in Map Reading Using Eye Tracking     

《The Cartographic journal》2013,50(3):202-213

Abstract

An assessment of British responses to a pan-European questionnaire conducted during the summer of 2003.  相似文献   

Mapping spiny aster infestations with QuickBird imagery     

J. H. Everitt  C. Yang  D. L. Drawe 《国际地球制图》2013,28(4):273-283

QuickBird satellite imagery acquired in June 2003 and September 2004 was evaluated for detecting the noxious weed spiny aster [Leucosyris spinosa (Benth.) Greene] on a south Texas, USA rangeland area. A subset of each of the satellite images representing a diversity of cover types was extracted and used as a study site. The satellite imagery had a spatial resolution of 2.8 m and contained 11-bit data. Unsupervised and supervised classification techniques were used to classify false colour composite (green, red, and near-infrared bands) images of the study site. Imagery acquired in June was superior to that obtained in September for distinguishing spiny aster infestations. This was attributed to differences in spiny aster phenology between the two dates. An unsupervised classification of the June image showed that spiny aster had producer's and user's accuracies of 90% and 93.1%, respectively, whereas a supervised classification of the June image had producer's and user's accuracies of 90% and 81.8%, respectively. These results indicate that high resolution satellite imagery coupled with image analysis techniques can be used successfully for detecting spiny aster infestations on rangelands.  相似文献   

新疆、青海、俄罗斯糖白玉的宝石学特征对比分析     

张攀  刘喜锋  李竞妍  陈美华 《地质科学译丛》2011,(4):31-38

为了查明新疆、青海、俄罗斯三地所产糖白玉的结构、成分和成因差异,在观察原料外观特征的基础上,采用常规宝石学方法、偏光显微镜、X射线粉末衍射仪和电子探针研究新疆、青海、俄罗斯糖白玉样品,从结构类型、矿物组成、化学成分和成因特征等方面进行对比分析。结果表明,以上三地糖白玉的主要矿物组成均为透闪石,次要矿物组成则各有不同。新疆、俄罗斯糖白玉以毛毡状变晶结构为主,青海糖白玉以纤维状变晶结构和纤维-隐晶质变晶结构为主;初步认定以上三地糖白玉的糖色为次生色,主要由褐铁矿导致。结合相关地质背景和风化作用特征,推测以上三地糖白玉不同的外观特征主要受玉体成矿后期和成矿期结束后周围环境变化的影响。  相似文献   

广东乳源彩石的矿物学特征及颜色成因研究     

罗书琼  刘迎新  施光海 《地质科学译丛》2013,(3):1-8

乳源彩石是具有华丽色彩的一种观赏石.采用偏光显微镜、扫描电子显微镜、电子探针、红外光谱仪以及X射线粉末衍射仪等测试手段对4块乳源彩石标本的显微结构、矿物组成和化学成分等进行测试与分析.结果表明,这些乳源彩石具有变粉砂结构,主要由石英组成（占总体质量分数的90％以上）,含少量云母,其它矿物的质量分数低,是一种浅变质的变石英粉砂岩;另外,4块乳源彩石样品的结晶度指数相近,结晶度指数最高的绿色样品推测是由于其含有后期充填的鲕状矿物导致.最后对乳源彩石样品的颜色成因进行了分析与探讨,认为其颜色为次生色,是由次生矿物组合、交代蚀变和氧化程度的不同而形成的.  相似文献   

Trace elements and mineral chemistry of silicified wood from Thailand: colours and elemental distribution     

S. Saminpanya 《Australian Journal of Earth Sciences》2016,63(7):873-884

Thai silicified woods were examined using electron probe microanalysis, yielding chemical data that characterised the samples into two groups: low and high silica contents (82—94 wt% and 94—98 wt%). The elements analysed in order of abundance include Si > Fe > Ca > Na > Al > Ti > K > Mg > Mn > Zr. Iron plays a major role in the colour range (red, orange, yellow, brown, grey and black) of the samples. Calcium is associated with Fe in the darker colours of the wood. Pseudo-crystallochemistry has been used for the substitution of trace elements for Si⁴⁺ in silica polymorphs. The atomic channels that run parallel to the c-axis of silica polymorphs or lattice defects, or even the charge balance for trivalent-ion substitution for Si⁴⁺, can accommodate monovalent ions (K⁺ and Na⁺). Vacant and atomic cavities, which are charged balanced by trivalent ions [Al³⁺ or Fe³⁺ substituting for Si⁴⁺], are commonly occupied by divalent ions (Ca²⁺, Mg²⁺ and Mn²⁺). Quadrivalent ions, Ti⁴⁺ and Zr⁴⁺ are non-structurally incorporated but form clusters of mineral inclusions in the samples. Several other trace-element contents are also in the form of mineral/fluid inclusions hosted in the woods.  相似文献   

提取江蓠琼脂新工艺条件的研究   总被引：1，自引：0，他引：1  

李来好  陈培基  王道公  吴燕燕 《中国海洋大学学报(自然科学版)》1995,(Z1)

提取江蓠琼脂新工艺条件的研究李来好，陈培基，王道公，吴燕燕（中国水产科学研究院南海水产研究所水产加工研究室）摘要采用＂高温稀碱法＂提取江蓠琼脂，系统地研究了江蓠的碱处理、漂白和提胶的新工艺条件。其主要特点是：（１）在碱处理中，添加了蒽衍生物，使琼脂的...  相似文献   

Dimorphism in the Ascidian Pyura stolonifera Near Melbourne, Australia, and its Evaluation Through Field Transplant Experiments     

J. E. Dalby  Jr 《Marine Ecology》1997,18(3):253-271

Abstract. On the central coast of Victoria, Australia, the ascidian Pyura stolonifera (H eller . 1878) assumes 2 morphs. a yellow form living exclusively on inner shores, and a brown morph mainly on outer coasts. Distributional surveys, morphological analyses and field transplant experiments were conducted as part of a multidisciplinary investigation designed to elucidate the environmental and genetic components of dimorphism in this species. Distributional surveys revealed that the 2 morphs have a parapatric distribution. Morphological analyses showed striking differences between morphs in colours of tissue types, external anatomy, morphometry and gravimetry. Possible ecological significances of this morphological differentiation are discussed. Transplant experiments, in which morphs were moved within and between habitats, yielded no evidence for morphological plasticity in adults of this species for the great majority of characters examined.  相似文献