The Changing Face of Synthetics in the Diamond Industry-Recent Developments and Reliable Identificat

来源 :2011中国珠宝首饰学术交流会 | 被引量 : 0次 | 上传用户:LIU_XX
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
  China is an increasingly important diamond market and as such will inevitably be seen as a potential market for synthetics and treated diamonds.One important contribution of the research carried out by De Beers was the production of the Diamond Verification Instruments: DiamondSure,DiamondView and DiamondPLus.DiamondSure can be used to screen out diamonds that could potentially be synthetics and DiamondView allows imaging of the fluorescence patterns associated with growth and therefore provides unambiguous identification of synthetics.Examples of typical features of various synthetics are given.The technical uses of single crystal diamond are currently expanding and the demands of these technologies for higher crystal qualities and larger sizes have helped drive the development of synthesis methods and these advances have enabled the production of material that could potentially be manufactured into polished gemstones.Whilst there have been significant developments both in the synthesis methods themselves and in post-growth treatments,detection capability has kept pace with these developments and continues to provide reliable identification.Accurate testing supporting full disclosure will ensure that consumers will be properly informed about their diamond purchases and will maintain the integrity of brands such as Forevermark into the future.
其他文献
所谓种内变异(intraspecific variation)是指同种生物的不同个体间的表型或遗传差异.根据这个定义,种内变异可能涉及生物性状的各个方面:既包括表型水平的形态、发育、生理、生活史等具有重要生态学意义的表型性状的变异,也包括基因组水平的功能未知的DNA序列变异.种内变异广泛存在于自然界的各种生物类群中,是现代生物学研究的核心主题之一.
会议
湿地水量的动态研究是陆地水循环研究的重要方面,也是水文模拟中的主要环节;同时,作为湿地生态系统洪水调节功能的表征,湿地水量的估算研究也具有重要的生态安全意义。通过确立水面(A)与水量(V)之间的关系,可以快速便捷地估算湿地水量。高原湿地地处大江大河上游,具有重要的生态保护意义,但由于缺乏基础研究条件,加之湿地水文情势复杂多变,使得高原湿地水文研究仅停留在水文因子的生态响应层面而不能深入认识其波动规
生物适应性进化过程不仅仅遗传了以DNA序列为基础的编码信息,而且在一定程度上继承了与环境经历相关的基因表达信息.DNA甲基化是表观遗传修饰的一种重要形式,在生物快速适应环境变化和表型进化过程中发挥着重要作用并赋予物种一种主动拓展自身生境的能力和可能性.甲基化在基因组中的总体分布情况被称为甲基化组(methylome),已经成为功能基因组研究的重要主题.
会议
生物多样性是地球上几十亿年来生命进化的结果,是生态系统不可缺少的组成部分,也是人类赖以生存的物质基础,为人类提供广泛的直接、间接和潜在价值。但现代社会人口的急剧增长、科学技术的不断发展带来了一系列的环境问题,对生物多样性造成了严重的威胁。保护生物多样性、保护丰富的生物资源、保护人类的生存环境已经成为刻不容缓的任务,世界各国也已开展了一些工作拯救濒临灭绝的物种和生物群落。生物多样性的保护是指对一个地
会议
公园绿地的防灾功能是城市综合减灾体系的一个组成部分,其空间分布能够反映公园应急避难场所供给与居民需求是否平衡,而避难可达性又反映了公园提供避难的可能性。结合防灾公园规划建设标准和空间可达性理论,采用2SFCA算法和Arcgis技术,研究昆明市城区公园的避难可达性。结果表明:昆明市城区公园整体应急避难能力较低;可达距离d0在2,000~2,500m时,避难可达性呈现中间低周边高的布局;当d0为2,0
Using the collected 433 heat flow values,we estimated the bases of methane hydrate stability zone (BHSZ),in northern South China Sea (NSCS).Through comparing BHSZs with the depths of bottom simulating
In 2001,the International Seabed Authority (ISBA) initiated the consideration relating to the Regulations for Prospecting and Exploration for Hydrothermal Polymetallic Sulphides and Cobalt-rich Ferrom
研究钻孔DGKS-9602位于冲绳海槽中部,岩芯长度为931cm,钻孔年代覆盖了氧同位素1~4阶段,年代可追溯至距今73ka.孢粉分析结果证明,孢粉带与氧同位素阶段有较好的对应关系,其中松属花粉与蒿属花粉比值(P/A)与海平面变化曲线相互吻合.应用非相似性类比法将钻孔孢粉样品与陆地表土孢粉样品进行欧氏距离计算,从而获得陆源物质来源的可能区域,进而分析了海平面波动下导致陆源区发生的可能变化.结果证明
The previous studies by the MASNUM research team have shown the effectiveness of the waveinduced mixing (Bv) in improving the simulation of upper-ocean thermal structure.The mechanisms of Bv are furth
The spatial and temporal variability and size fractionation of chlorophyll a (Chl a) were investigated in the tropical and subtropical Pacific Ocean during four survey cruises from 2005 to 2009.The su