高温高压合成金刚石的Raman光谱与XPS研究

高温-高压合成金刚石的显微Raman光谱与XPS C1s谱研究表明:铁基与镍基合成金刚石都是品级较高的金刚石,且前者品级更高,更易长大。以铁基与镍基作触媒合成的金刚石表面sp3碳原子的百分含量分别达到82.4%和75.45%。研究结果进一步启示,在金刚石成核后,除了需要有碳原子的补充外,有效抑制生长界面碳原子sp3键向sp2键退化,将会是金刚石能否长大的关键性问题。     

地质灾害对高速公路隧道工程长度及埋深激增的响应研究

在交通基础工程的快速发展过程中,隧道工程的建设呈现出"长、深、大"的发展趋势。研究表明,隧道的长大深埋化会极大的加剧地质灾害的发生,尤其是增大了发生硬岩岩爆、高压突(涌)水、高地温和软岩大变形等特殊且更大影响地质灾害的风险。针对上述地质灾害的特点,指出了各类地质灾害的应对策略和处理措施。建议系统总结地质条件相似区域的隧道工程建设经验,形成针对性的长大深埋隧道成套建设技术和地方技术标准。     

深埋隧道岩爆灾害及其预防的关键技术研究

岩爆是深埋隧道建设面临的一类危害性极大的地质灾害,这类灾害制约了深埋隧道的建设并引起了学术界和工程实践的广泛关注。基于理清岩爆的特征和系统的总结岩爆灾害的预防技术的目的,通过对已有相关研究成果和工程实践经验进行了全面的总结梳理。结果表明,岩爆的影响因素非常多且机制复杂,工程实践中已形成了单一判据、复合多元判据及系统工程判据的多种预判方法。通过预测圈定岩爆的时间、地点、危险程度等,可在不同阶段有针对性的采取防治措施以降低岩爆带来的危害。     

Mineralization-related geochemical anomalies derived from stream sediment geochemical data using multifractal analysis in Pangxidong area of Qinzhou-Hangzhou tectonic joint belt, Guangdong Province, China

Distinguishing geochemical anomalies from background is a basic task in exploratory geochemistry. The derivation of geochemical anomalies from stream sediment geochemical data and the decomposition of these anomalies into their component patterns were described. A set of stream sediment geochemical data was obtained for 1 880 km 2 of the Pangxidong area, which is in the southern part of the recently recognized Qinzhou-Hangzhou joint tectonic belt. This belt crosses southern China and tends to the northwest (NE) direction. The total number of collected samples was 7 236, and the concentrations of Ag, Au, Cu, As, Pb and Zn were measured for each sample. The spatial combination distribution law of geochemical elements and principal component analysis (PCA) were used to construct combination models for the identification of combinations of geochemical anomalies. Spectrum-area (S-A) fractal modeling was used to strengthen weak anomalies and separate them from the background. Composite anomaly modeling was combined with fractal filtering techniques to process and analyze the geochemical data. The raster maps of Au, Ag, Cu, As, Pb and Zn were obtained by the multifractal inverse distance weighted (MIDW) method. PCA was used to combine the Au, Ag, Cu, As, Pb, and Zn concentration values. The S-A fractal method was used to decompose the first component pattern achieved by the PCA. The results show that combination anomalies from a combination of variables coincide with the known mineralization of the study area. Although the combination anomalies cannot reflect local anomalies closely enough, high-anomaly areas indicate good sites for further exploration for unknown deposits. On this basis, anomaly and background separation from combination anomalies using fractal filtering techniques can provide guidance for later work.     

高温高压合成金刚石的Raman光谱与XPS研究

高温-高压合成金刚石的显微Raman光谱与XPS C1s谱研究表明：铁基与镍基合成金刚石都是品级较高的金刚石，且前者品级更高，更易长大。以铁基与镍基作触媒合成的金刚石表面sp^3碳原子的百分含量分别达到82．4％和75．45%。研究结果进一步启示，在金刚石成核后，除了需要有碳原子的补充外，有效抑制生长界面碳原子sp^3键向sp^2键退化，将会是金刚石能否长大的关键性问题。     

粤桂边境煌斑岩地球化学特征及其地质意义

通过对粤桂边境贵金属矿床紧密相关的云煌岩进行地球化学分析,结果显示N-MORB标准化的微量元素蛛网图表现为相对富集Rb、Ce和Sm及亏损Ta和Sr。煌斑岩的稀土总量为（82.33~215.30）×10^-6,平均值为143.20×10^-6,是原始地幔的20倍。轻稀土含量为（75.01~199.01）×10^-6,重稀土含量为（7.31~16.29）×10^-6,轻重稀土含量比值为9.26~12.22、平均为10.90。经球粒陨石标准化,煌斑岩的稀土配分曲线表现为右倾和极弱的Eu负异常。研究区的煌斑岩具有地幔和下地壳的双重特点,其中煌斑岩的幔源地球化学指标δZr/δNb、δTh/δLa值分别为16.02~20.01和0.14~0.20,而壳源组成特征δLa/δNb、δSm/δNd和δNb/δU值分别为2.06~3.78、0.18~0.19、5.29~22.37,这可能说明煌斑岩属于原始幔源岩浆经下地壳物质混染的产物。在研究区的贵金属成矿作用过程中,煌斑岩可能扮演了“矿化剂来源”和“能量供体”的角色。     

西秦岭造山带硅质岩的成岩成矿演化特征——以八方山-二里河矿区赋矿硅质岩为例

硅质岩是一类广泛分布于造山带内的岩石,其组成简单且具有较高的稳定性.然而,硅质岩的这种高稳定性是宏观的,在微观上仍然会保留地质演化和成岩过程的痕迹,可以从中提取造山带演化过程中的温度、压力和流体等重要信息.秦岭造山带西段八方山一二里河Pb-Zn矿区的赋矿硅质岩的光学显微镜、激光拉曼(RAMAN)、X射线粉晶衍射(XRD)和扫描电镜-能谱(SEM-EDS)研究结果表明,该硅质岩明显受到了造山作用、成矿作用和重结晶作用等的改造.显微镜下,硅质岩主要由细一微晶石英和少量的碳酸盐矿物(方解石、白云石等)组成.微裂隙和脉体的存在反映其曾经受到张应力作用,而微褶皱以及矿物的定向排列则说明其受到压应力的影响.XRD和SEM分析也指示其遭受了压应力作用.RAMAN原位微区分析结果揭示了石英的重结晶作用及其受流体的影响.硅质岩的SEM图片中金属硫化物的线状和浸染分布可能与温度、压力和流体等对硅质岩进行了不同程度的改造有关.     

氢预处理与高压影响下石墨的Raman光谱研究及在金刚石高温高压合成中的意义

氢预处理及高压作用后石墨的Raman光谱的研究表明：酸浸泡及氢等离子体预处理均可以在石墨中造就有利于金刚石成核的-CH3：C—H类金刚石碳区，并使石墨的有序度显著降低；5．4GPa高压作用后，氢预处理石墨的有序度会有所提高．但不会超过常压下未经氢预处理石墨的有序度；高压下石墨向金刚石转变，石墨片层确实有褶曲，但在此之前可能存在一个石墨与氢等造就类金刚石碳区有关的必然环节。     

Biogenic characteristics of Mesozoic cherts in southern Tibet and its significance

The Xialu chert, which contains abundant biological information, were investigated by major element analysis, micro-Raman, SEM and EPMA. The results show that SiO2 content of chert is 84.12%-93.08%, averaging 89.84%. The close packed structures of low degree crystallinity of quartz indicate the hydrothermal origin. SiO2 of modern hot springs exhibit loose silica pellets and nodular, beaded structures. Under polarization microscope, the presence of biological skeleton structures indicate that biological activities are involved in the hydrothermal deposition, which correspond to the geochemical characteristics： w（SiO2）/ w（K2O＋Na2O）, w（SiO2）/w（Al2O3） and w（SiO2）/w（MgO）, with average values of 295.29, 68.88 and 284.45, respectively. SiO2 is enriched in the organism（radiolarian） centers, the degree order of SiO2 within the biologic structures is much higher than that of outside. The impurity minerals albites are formed earlier than the original deposition. Kaolinites, feldspars and mixture of organic materials display lower degree of crystallinities and accumulate as vermicular aggregates.     

Fe—C（H）系高温高压合成金刚石多晶的RAMAN与PL光谱研究

Fe-C(H)系高温高压合成金刚石多晶的FESEM,RAMAN和PL光谱研究表明:构成多晶的金刚石晶粒多为八面体形态,同时其形成环境比较稳定.在金刚石晶粒中存在与氮相关、与镍相关及塑性形变等缺陷,且不同金刚石晶粒中的缺陷不完全相同.基于镍易在金刚石中形成发光中心及氢可以加速金刚石多晶的形成,为了提高金刚石单晶的质量,应该尽量在压腔中使用纯铁作为触媒,且在引入氢的同时除氮.