广西陆川蛇纹石玉的岩相结构及成矿机理

应用外束质子激发X射线荧光光谱法、X射线衍射、激光拉曼光谱、扫描电子显微镜等无损分析技术,对广西陆川蛇纹石玉的成分、物相和结构进行分析。X射线衍射结果显示样品的衍射峰主要位于0.724、0.456、0.362、0.248、0.153和0.150 nm处,表明陆川蛇纹石玉主要矿物成分是蛇纹石,同时伴生方解石矿物与蛇纹石形成穿插交织结构。成矿机理分析表明,陆川蛇纹石玉是由白云质大理岩热液交代作用形成的,和广东的信宜玉均属于富镁碳酸盐型蛇纹石。拉曼光谱显示叶蛇纹石的特征峰位于229、376、457、686和1046 cm-1处,纤蛇纹石的特征峰位于228、345、386、624、690和1102 cm-1处,通过激光拉曼光谱可以快速区分陆川蛇纹石玉中纤蛇纹石和叶蛇纹石两种不同结构的蛇纹石亚种。     

大别山碧溪岭榴辉岩激光探针40Ar-39Ar年龄

采用激光探针⁴⁰Ar-³⁹Ar法对大别山碧溪岭榴辉岩样品中的石榴石和绿辉石单颗粒矿物进行原位测定,获得了两条等时线年龄。结果表明该区榴辉岩经历了两期构造热事件:榴辉岩超高压变质作用发生在加里东期,燕山期年龄为快速抬升折返的热事件年代记录。     

岩石裂纹附近的变形局部化与破坏——激光全息干涉法的应用

本文介绍了应用激光全息干涉法观测单轴压缩条件下裂纹附近的离面位移场和岩石的变形破坏过程。着重指出了裂纹构造活动与微裂隙丛集发育的变形局部化前兆在这种破坏过程中的相互关联,并就其所反映的震源物理本质进行了讨论。     

Discriminating Bio-Induced and Detrital Sedimentary Processes from Particle Size Distribution of Carbonates and Non-Carbonates in Hard Water Lake Sediments

Particle size distribution (PSD) and carbonate content are two of the most frequently used parameters for describing lake sediments. This paper presents a method for rapidly measuring both these parameters using a laser particle-sizer, as well as an original way in which to separately interpret the PSD of the carbonate and non-carbonate fractions. Differential particle size analyses are produced by measuring the PSD of each sample twice. The first PSD is measured using the bulk sample. The second PSD is measured after the carbonate fraction has been completely dissolved by adding hydrochloric acid to the sample. As well as particle size analyses, laser particle-sizers automatically give obscuration values for the samples being analysed. By comparing the obscuration value for the bulk sample with the value for the de-carbonated fraction, the carbonate content of the sediment can be determined. In order to test the accuracy of the method, the results were compared with chemical analyses of carbonate content. This comparison showed that when applied to diatom-rich samples the method underestimates the carbonate content. This is due to the fact that the differential particle size method measures the volume concentrations of the carbonate and non-carbonate fractions, whereas chemical analysis measures the weight concentrations. As diatoms are hollow and have relatively low-densities, differential particle size analyses of diatom-rich samples overestimate the non-carbonate fraction. Despite this limitation, and bearing in mind that laser particle-sizer distributions are expressed in terms of volume percent for each size class and not weight percent, PSDs can provide useful data for interpreting sedimentary processes. One of the main advantages of this method is that it can be used to separate the PSDs of the carbonate (autochthonous) fraction and the non-carbonate (allochthonous) fraction from the PSD of the bulk sample. The value of such an approach was demonstrated by the analysis and interpretation of a 9 m-long core from Lake Bourget in France. An analysis of the bulk sample PSDs plotted as a function of depth showed the consistency of sedimentary processes over the last 7200 years. Amongst these processes, it was possible to identify two modes of clastic material deposition: river-borne fine sedimentation during major floods and gravity reworking of sandy sediment from the lakeshore.     

人工合成包裹体的实验研究及其在激光拉曼探针测定方面的应用

利用愈合人工水晶裂隙合成人工流体包裹体的技术,在0．5～1kb,350～800℃的范围内,对纯H2O体系、NaCl-H2O体系、KCl—H2O体系进行了人工合成包裹体实验研究。并对这些合成的包裹体进行了详细的测温学研究,证实了合成包裹体是母液成分的真实代表,完全可以用来做为自然界包裹体研究的标样。同时利用合成包裹体采集了均一、和冷冻状态下的拉曼谱,讨论了合成包裹体在激光拉曼探针测定方面的某些可能的应用。研究表明,合成包裹体是了解包裹体的形成机理和进行地质流体性质研究的一种十分有效的手段,在地质流体和实验地球化学研究领域有着广阔的应用前景。     

基于1．2m望远镜白适应光学系统激光信标转盘式机械快门的研究

基于激光信标发射和接收共光路系统中探测器受杂散光影响的关键问题,设计了一种新型转盘式机械快门装置,对光信号进行高频率开关控制,从而对自适应光学系统的波前探测器起到彻底保护作用。设计时,分析了瑞利信标的采样厚度以及快门开关与脉冲激光器的发射、探测器探测时间的时序控制。     

Plasma Jet Experiments Using LULI 2000 Laser Facility

We present experiments performed with the LULI2000 nanosecond laser facility. We generated plasma jets by using specific designed target. The main measured quantities related to the jet such as its propagation velocity, temperature and emissive radius evolution are presented. We also performed analytical work, which explains the jet evolution in some cases.     

新疆北天山西段构造应力场分析

利用地表构造形迹、地震震源机制解、现代水系展布的优势方向以及激光全息光弹模拟等综合分析方法,研究了北天山西段(东经82°～86°)地壳构造应力场的基本特征。指出,该区构造应力场的主压应力方向为近南北向。通过激光全息光弹实验获得模型的等差线及等和线条纹图,从而求解各点的主张应力σ_1主压应力σ_2和最大剪应力τ_max的相对值并绘制相应的等值线图,结果发现:实验区σ_1值普遍偏低,σ_2值明显偏大,说明本区处于整体受压状态。τ_max值的分布较均匀,仅在一些断裂的交汇部位和端点剪应力值较高。分析结果认为:萨尔萨拉西南、独山子——安集海断裂西端、乌苏林场西南、阿尔夏特一带、婆罗科努达坂东南都是围压很高的剪应力集中区。这些地区易积累大量的应变能而产生突发式剪切破裂和粘滑引起强烈地震,是在地震预报中值得注意的地震危险地段。     

阿尔金地区构造应力场研究

用软材料和激光全息光弹模拟实验方法,分析了阿尔金地区现代构造应力场的特征和在区域应力场作用下阿尔金断层的活动规律以及大震前后震区应力场的调整情况,结果表明:阿尔金地区现今构造应力场主压应力轴近南北向,南边印度板块向北推进的过程中,使得青藏高原西北边界的阿尔金断裂各段的活动性质和滑移速度不同。东西两段左旋位移较明显;中段呈明显压性;应力集中区分布在一些特殊构造部位。模拟大震应力释放反映,大震后震中区附近剪应力值迅速下降,周围一些地区的剪应力值升高,形成未来地震危险区。