微束分析测试技术十年(2011~2020)进展与展望

现代地球科学研究的重大突破在很大程度上取决于观测和分析技术的创新。新世纪以来,我国地球科学领域引进了一批高性能新型微束分析仪器设备,建立了一批高规格的实验室。本文回顾了近十年来微束分析技术与方法的主要进展及其在地球科学研究中的应用实例,包括电子探针、扫描电镜、透射电镜、大型离子探针、纳米离子探针、飞行时间二次离子质谱、激光剥蚀等离子体质谱、激光诱导原子探针、原子探针技术、显微红外光谱、同步辐射等,这些分析技术的进步和广泛应用极大地提高了我们对地球和行星演化历史及许多地质过程的理解。今后,应加快微束分析的新技术、新方法和新标准的开发,特别是高水平人才队伍建设,提高创新能力并在国际学术舞台上发挥重要作用。     

北京密云水库表层沉积物磁性矿物的鉴别

本文对密云水库表层沉积物中的磁性矿物进行了岩石磁学和透射电子显微学的综合研究.本实验建立的磁选方法实现将70%～85%左右的磁性矿物从沉积物中分离出来.岩石磁学研究表明,密云水库沉积物中的磁性矿物以多畴和单畴磁铁矿为主,还含有少量高矫顽力弱磁性载磁矿物（可能为赤铁矿）.对磁选矿物的透射电镜观测表明,样品中部分单畴磁铁矿具有纳米尺寸和化学纯度高等特点,为拉长的立方-八面体磁铁矿,是趋磁细菌产生的化石磁小体;多畴磁铁矿多数具有微米尺寸,形状不规则,为碎屑成因;超顺磁磁铁矿粒径约为5～20 nm,且含硅、铝等元素,可能为自生成因.研究结果表明,岩石磁学和透射电子显微学的综合应用可以更全面、准确地分析沉积物中磁性矿物的成分、含量、粒径和化学成分等信息,为环境磁学、生物地磁学和古地磁学研究提供依据.     

黄铁矿热转化矿物相变过程的岩石磁学研究

对天然黄铁矿样品在氩气和空气环境中受热发生的矿物相变过程进行了系统的岩石磁学研究,结果表明：氩气环境（还原环境）下,黄铁矿受热分解转化的产物是磁黄铁矿,其粒度为单畴,矫顽力和剩磁矫顽力分别约为20和30mT,它在还原环境中是稳定的．而空气环境（氧化环境）中黄铁矿受热分解、转化后的最终产物为单畴赤铁矿,FORC图显示其矫顽力高达1400mT,相应的热转化序列为：黄铁矿→磁黄铁矿→磁铁矿→赤铁矿．上述结果对于理解还原环境沉积物的磁性、岩石次生化学剩磁和陨石磁学性质都具有重要参考意义．     

Organic and inorganic matter in Louisiana coastal waters: Vermilion, Atchafalaya, Terrebonne, Barataria, and Mississippi regions

Chromophoric dissolved organic matter (CDOM) spectral absorption, dissolved organic carbon (DOC) concentration, and the particulate fraction of inorganic (PIM) and organic matter (POM) were measured in Louisiana coastal waters at Vermilion, Atchafalaya, Terrebonne, Barataria, and Mississippi River locations, in 2007-2008. The range of CDOM was 0.092 m⁻¹ at Barataria in June 2008 to 11.225 m⁻¹ at Mississippi in February 2008. An indicator of organic matter quality was predicted by the spectral slope of absorption coefficients from 350 to 412 nm which was between 0.0087 m⁻¹ at Mississippi in May 2008 and 0.0261 m⁻¹ at Barataria in June 2008. CDOM was the dominant component of light attenuation at Terrebonne and Barataria. Detritus and CDOM were the primary components of light attenuation at Vermilion, Atchafalaya, and Mississippi. DOC ranged between 65 and 1235 μM. PIM ranged between 1.1 and 426.3 mg L⁻¹ and POM was between 0.3 and 49.6 mg L⁻¹.     

Expression of superoxide dismutase (SOD) genes from the copper-exposed polychaete, Neanthes succinea

To evaluate the superoxide dismutase (SOD) genes as a potential indicator of environmental stress, we cloned and sequenced the full-length cDNA of a Cu/Zn-SOD and Mn-SOD genes from the marine polychaete, Neanthes succinea. Ns-Cu/Zn- and Mn-SOD expression was measured using quantitative real-time RT-PCR in response to the oxidative stress induced by copper in the form of CuCl2. Ns-Cu/Zn-SOD expression increased in a dose dependent manner but the increase of Mn-SOD expression was evident only at a high concentration of copper. Particularly, Ns-Mn-SOD dramatically increased in the 72 μg/L CuCl2-exposed groups, indicating that both Ns-SOD genes were induced by copper exposure. These results suggest that Ns-Cu/Zn- and Ns-Mn-SOD would play important roles in the detoxification of cellular oxidative stresses in the polychaete, N. succinea. Furthermore, as part of field work, the marine polychaete, N. succineaCu/Zn-SOD mRNA collected from the polluted area was accordingly upregulated in expression but not for NS-Mn-SOD.     

渗透率各向异性储层中斜井倾斜引起的表皮效应

本文介绍的斜井表皮效应的解决方法及效果表明，若按以前对各向同性的设想，就会把正常沉积地层中，特别是垂向渗透率较低的层状储层中常见的各向异性的表皮因子绝对值估计得太大。本文给出了井斜引起的表皮效应与储层厚度、各向异性指数和井斜函数关系式及其图解。大斜度井的动态可近似地用一直井产量关系曲线去描述，而这种关系这种表皮效应而得以增强，其其实与井生产长度相同情况下，用众所周知的水平井产量公式所得结果毫无区别