Authigenic sulfide minerals and their sulfur isotopes in sediments of the northern continental slope of the South China Sea and their implications for methane flux and gas hydrate formation

This is a report of the study of the authigenic sulfide minerals and their sulfur isotopes in a sediment core (NH-1) collected on the northern continental slope of the South China Sea, where other geo-physical and geochemical evidence seems to suggest gas hydrate formation in the sediments. The study has led to the findings: (1) the pyrite content in sediments was relatively high and its grain size relatively large compared with that in normal pelagic or hemipelagic sediments; (2) the shallowest depth of the acid volatile sulfide (AVS) content maximum was at 437.5 cm (>2 μmol/g), which was deeper than that of the authigenic pyrite content maximum (at 141.5-380.5 cm); (3) δ 34S of authigenic pyrite was positive (maximum: 15‰) at depth interval of 250-380 cm; (4) the positive δ 34S coincided with pyrite enrichment. Compared with the results obtained from the Black Sea sediments by Jorgen-sen and coworkers, these observations indicated that at the NH-1 site, the depth of the sulfate-methane interface (SMI) would be or once was at about 437.5-547.5 cm and the relatively shallow SMI depth suggested high upward methane fluxes. This was in good agreement with the results obtained from pore water sulfate gradients and core head-space methane concentrations in sediment cores collected in the area. All available evidence suggested that methane gas hydrate formation may exist or may have existed in the underlying sediments.     

泥砂钟乳——一种特殊的沉积构造

黄河是我国的第二大河流,因流经水土流失极为严重的黄土地区而含大量泥砂,使其下游     

贵州早、中三叠世间绿豆岩粘土矿物学研究

运用Ｘ射线衍射、红外光谱、差热分析、扫描电镜等分析方法，对贵州绿豆岩进行了系统的粘土矿物学研究。确定了贵州绿豆岩中粘土矿物主要有伊利石、蒙脱石、高岭石和伊利石／蒙脱石混层矿物，为贵州绿豆岩的成因研究和开发利用提供了依据。     

矿物单体解离度线段测定值的校正

引荐了Ｋ．Ｂａｂａ等人的线段品级与体积品级的转换方阵和Ｔ．Ｐ．Ｍｅｌｏｙ的连生颗粒体积品级分布函数。在此基础上提出了解离度线段测量结果的校正方法     

高性能、多功能纳/微杂化碳纤维复合材料

高性能轻质复合材料是新材料技术与产业发展的重要方向之一，已成为各国航天航空、国防科技发展的重要支撑材料。其中高性能轻质复合材料通常是用高性能纤维与高性能基体按性能设计要求，通过一定的工艺复合而成的一类新型工程材料。目前，先进复合材料即以碳纤维为增强体的树脂型复合材料，     

神府3^—1煤微粉化与化学改性

进行了神3^-1煤原位力化学改性超细活性粉体制备，并从吸油值、粒度特性两方面对粉表面性质进行了表征。结果表明：行星球磨进行神府3^-1煤的超细改性可行。不同系列偶联剂对改性效果影响不一，但都存在最佳剂量，为神府3^-1煤的进一步材料化利用提供了有效途径。     

高性能网络与综合布线

主要讨论高性能网络与综合布线之间的关系，要得到高性能的网络，必须有与之相匹配的布线系统，这是网络建设的关键。     

推广应用C60以上高性能混凝土的设计施工关键技术与管理政策研究

高性能混凝土是指具有高工作性、高耐久性和适宜强度的混凝土，被世界各国公认为21世纪的混凝土。随着我国经济持续和快速的发展，混凝土结构的施工安全性、使用耐久性以及建造经济性，已经引起了工程界广大技术人员的高度重视。