表面接触角的测量及表面张力在宝玉石鉴定中的应用

表面张力是固体表面重要的物理化学参数之一,其大小与温度和界面两相物质的性质有关。基于Young方程的推导,使用接触角测量法计算固体表面张力已被广泛应用于表面科学和工程领域。宝玉石材料大多具有光洁的表面,在接触角测量的准确性方面较其他表面不均一的固体材料具有明显的技术优势。本文运用现代仪器(FTA200动态接触角测量仪)测量了15个天然和合成宝玉石品种(钻石、合成碳硅石、合成立方氧化锆、碧玺、托帕石、翡翠、琥珀等),以及经覆膜和充填2种处理方法的宝玉石样品(镀膜钻石、覆膜托帕石、覆膜翡翠、覆膜琥珀、充填碧玺)的表面接触角,并运用公式计算其表面张力。测试数据表明,不同品种宝玉石的接触角数值存在差异,如钻石的接触角值为56.68°,其仿制品立方氧化锆的接触角值为37.79°;覆膜处理与未经覆膜处理的天然宝玉石的接触角数值差异明显,如琥珀的接触角值为92.49°,覆膜琥珀的接触角值为66.49°;充填处理宝玉石接触角的测试由于控制液滴的大小受条件限制操作难度较大,测试结果不能准确表达为裂隙中充填物的接触角数值,故充填处理的宝石不宜采用此方法进行区分。研究表明,对于部分宝玉石品种和覆膜处理宝玉石,其表面接触角及表面张力数值差异显著,可以作为宝玉石品种的辅助鉴定依据;尤其是运用接触角的差异对于宝玉石鉴定具有较好的判别性,能够对不同品种的天然宝玉石与表面覆膜的宝玉石样品进行有效区分。与常规宝石检测方法(如红外光谱、折射率测量方法)对比,接触角测量方法具有测量准确、操作简便,不破坏样品的特点,符合宝玉石无损鉴定的基本原则,且能够安全快速地测量高折射率宝石,可以解决宝玉石表面覆膜等与表面物性相关的检测疑难问题。     

Time-Varying Multifractal Characteristics and Formation Mechanism of Loaded Coal Electromagnetic Radiation

Dynamic collapses of deeply mined coal rocks are severe threats to miners. To predict the collapses more accurately using electromagnetic radiation (EMR), we investigate the time-varying multifractal characteristics and formation mechanism of EMR induced by underground coal mining. A series of uniaxial compression and multi-stage loading experiments with coal samples of different mechanical properties were carried out. The EMR signals during their damage evolution were monitored in real-time; the inherent law of EMR time series was analyzed by fractal theory. The results show that the time-varying multifractal characteristics of EMR are determined by damage evolutions process, the dissipated energy caused by damage evolutions such as crack propagation, fractal sliding and shearing can be regard as the fingerprint of various EMR micro-mechanics. Based on the Irreversible thermodynamics and damage mechanics, we introduced the damage internal variable, constructed the dissipative potential function and established the coupled model of the EMR and the dissipative energy, which revealed the nature of dynamic nonlinear characteristics of EMR. Dynamic multifractal spectrum is the objective response of EMR signals, thus it can be used to evaluate the coal deformation and fracture process.     

东昆仑南缘布青山地区哈尔郭勒玄武岩地球化学特征及其地质意义

哈尔郭勒玄武岩位于东昆仑南缘布青山地区。详细的地球化学研究表明哈尔郭勒玄武岩可以分为碱性玄武岩和亚碱性玄武岩,其中碱性玄武岩的∑LREE=63.8×10-6~175.36×10-6,∑HREE=14.46×10-6~28.56×10-6,∑LREE/∑HREE=4.41~6.14,(La/Yb)N=4.14~6.71,(Ce/Yb)N=3.31~5.12,δEu=1.03~1.17,具有与洋岛玄武岩(OIB)相似的稀土配分模式;亚碱性玄武岩的∑LREE=11.07×10-6~29.95×10-6,∑HREE=12.56×10-6~25.41×10-6,∑LREE/∑HREE=0.88~1.54,(La/Yb)N=0.29~0.74,(Ce/Yb)N=0.37~0.77,δEu=1.02~1.22,具有正常洋中脊玄武岩(N-MORB)的稀土元素地球化学特征。这表明哈尔郭勒玄武岩是OIB与N-MORB的共生组合。布青山地区哈尔郭勒玄武岩中的OIB形成于洋脊附近的海山或洋岛环境,岩浆源区可能为EMⅡ型富集地幔;N-MORB形成于洋脊环境,起源于亏损地幔。哈尔郭勒玄武岩为布青山地区晚古生代存在洋盆提供了更充分的证据。     

湖南禾库地区水系沉积物地球化学特征及找矿预测

依据1∶5万水系沉积物测量资料,分析研究了湖南禾库地区水系沉积物地球化学特征。对元素分布、单元素异常、元素相关性、异常元素组合等特征的研究表明水系沉积物地球化学测量方法在高山峻岭、地形复杂的禾库地区有良好的找矿效果,并优选了嗅脑和杉木冲2处铅锌找矿远景区。     

江南造山带东段桃岭岩体的地球化学特征及其成因

位于江南造山带东段赣东北地区的桃岭岩体地球化学特征总体表现为高钾钙碱性系列,弱过铝质-强过铝质,高Mg#值。桃岭岩体富集轻稀土和大离子亲石元素,亏损高场强元素,具弱的Eu负异常(δEu=0.62~0.81)(样品TL-1除外δEu=0.47)。锆石LA—ICPMS U—Pb定年获得桃岭岩体的成岩年龄为早白垩世(140±1)Ma。岩体初始~(87)Sr/~(86)Sr为0.7131~0.7141,ε_(Nd)(t)值为-7.43~-6.71。结合前人研究,笔者认为早白垩世(约140 Ma)交代的地幔发生部分熔融,幔源岩浆底侵,使地壳深处(至少40 km)的变质沉积岩发生部分熔融,并且与少量的幔源岩浆发生了岩浆混合作用,形成了桃岭岩体。     

西天山铁木里克铁矿床矿物学及稳定同位素特征

铁木里克铁矿是西天山阿吾拉勒成矿带上一个高品位的磁铁矿矿床,赋存于石炭纪大哈拉军山组火山岩中。矿区围岩蚀变较弱,主要以低温热液阶段的绿泥石化和绿帘石化为主。根据野外矿石组构以及镜下观察,该矿床可以划分为四个成矿阶段。目前该矿床的研究程度较低,矿床成因存在较大争议。磁铁矿和赤铁矿的电子探针结果显示,该矿床的形成与岩浆-热液系统密切相关;辉石和角闪石的电子探针结果显示,辉石未发生蚀变,只有角闪石轻微地发生了阳起石化。矿石中的黄铁矿硫同位素(0.1‰~2.9‰)显示具有深源地幔特征,磁铁矿的氧同位素(-2.7‰~0.5‰)暗示岩浆热液对成矿具有重要作用,以及成矿晚期低温热液过程对早先形成的磁铁矿起到了改造作用。结合区域铁矿带的成矿地质特征,本文认为铁木里克铁矿的形成主要与岩浆-热液系统密切相关,在大量磁铁矿形成之后,有少量成矿流体与海水混合,对矿床和围岩进行了低温热液蚀变,形成了充填在磁铁矿矿石气孔中的赤铁矿和黄铁矿。     

云南罗平复杂地层煤矿勘查泥浆体系的研究与应用

云南省曲靖市罗平县红丫口煤矿勘探项目临近大断裂带,受多期构造地质作用影响,走向逆断层发育,且发育有横向平移断层和少量正断层。地层受挤压变形严重,岩层倾角普遍较大,局部直立至倒转,地层破碎。上部漏水严重,下部钻遇多条断层破碎带以及煤系地层,造成钻进效率低下,钻孔事故频繁,甚至钻孔报废,严重影响勘查工作的顺利进行。针对这一系列的施工难题,经过多次研究和反复试验,探索出一种适合该矿区煤矿勘察复杂地层钻进的泥浆,保障了勘查项目的顺利完成。     

滇西“三江”地区临沧花岗岩基中三叠世碱长花岗岩的发现及其意义

在野外调研的基础上,对滇西“三江”地区临沧花岗岩基中勐库碱长花岗岩体的年代学、岩石学和地球化学开展了较系统的研究。结果显示,勐库岩体的锆石LA-ICP-MS U-Pb年龄为236.2±3.7 Ma,表明岩体应形成于中三叠世,而非前人认为的新生代。全岩主、微量元素,Sr同位素和锆石微量元素特征显示岩体属于S型花岗岩系列,来自于与临沧花岗岩基相类似的地壳沉积物源区的部分熔融,并经历了高程度的结晶分异作用。以勐库岩体为代表的碱长花岗岩与临沧花岗岩基形成时代一致,表明碱长花岗岩应为临沧花岗岩基的重要组成部分。除已报道的黑云母二长花岗岩类和黑云母花岗闪长岩类外,临沧花岗岩基还应包括较广泛分布的碱长花岗岩类。本文同时揭示,由于临沧花岗岩基中以勐库岩体为代表的碱长花岗岩并非早前认为的新生代岩体,“三江”南段特别是临沧地块前人划分的新生代岩体分布范围和规模可能需要重估。     

深水碳酸盐岩沉积体系与储层发育控制因素 ——以中东H油田白垩系Khasib组为例

深水碳酸盐岩是有利的油气储集岩,中东地区上白垩统Khasib组缓坡型深水碳酸盐岩是重要的产油层系.伊拉克H油田Khasib组储层非均质性较强,储层发育特征及控制因素、油气分布规律不清,制约了选区评价及勘探部署.在区域地质调研的基础上,基于岩心、薄片和测井资料,对H油田Khasib组岩相、沉积微相和沉积模式、储层发育控制...     

Geochemical features and origin of natural gas in heavy oil area of the Western Slope,Songliao Basin,China

The Western Slope of the Songliao Basin is rich in heavy oil resources (>70 × 10⁸ bbl), around which there are shallow gas reservoirs (∼1.0 × 10¹² m³). The gas is dominated by methane with a dryness over 0.99, and the non-hydrocarbon component being overwelmingly nitrogen. Carbon isotope composition of methane and its homologs is depleted in ¹³C, with δ¹³C₁ values being in the range of −55‰ to −75‰, δ¹³C₂ being in the range of −40‰ to −53‰ and δ¹³C₃ being in the range of −30‰ to −42‰, respectively. These values differ significantly from those solution gases source in the Daqing oilfield. This study concludes that heavy oils along the Western Slope were derived from mature source rocks in the Qijia-Gulong Depression, that were biodegraded. The low reservoir temperature (30–50 °C) and low salinity of formation water with neutral to alkaline pH (NaHCO₃) appeared ideal for microbial activity and thus biodegradation. Natural gas along the Western Slope appears mainly to have originated from biodegradation and the formation of heavy oil. This origin is suggested by the heavy δ¹³C of CO₂ (−18.78‰ to 0.95‰) which suggests that the methane was produced via fermentation as the terminal decomposition stage of the oil.