Experimental abiotic synthesis of methanol in seafloor hydrothermal systems during diking events

The abiotic synthesis of organic compounds in seafloor hydrothermal systems is one mechanism through which the subsurface environment could be supplied with reduced carbon. A flow-through, fixed-bed laboratory reactor vessel, the Catalytic Reactor Vessel (CRV) system, has been developed to investigate mineral–surface promoted organic synthesis at temperatures up to 400°C and pressures up to 30 MPa, conditions relevant to seafloor hydrothermal systems. Here we present evidence that metastable methanol can be directly synthesized from a gas-rich CO₂–H₂–H₂O mixture in the presence of a mineral substrate. Experiments have been performed without a substrate, with quartz, and with a mixture of quartz and magnetite. Temperatures and pressures in the experiments ranged from 200°C to 350°C and from 15 to 18 MPa, respectively. Maximum conversion of 5.8×10⁻⁴% CO₂ to CH₃OH per hour was measured using a mixture of magnetite and quartz in the reactor. After passivation of the stainless steel reactor vessel, experiments demonstrate that methanol is formed at temperatures up to 350°C in the presence of magnetite, and that the formation rate decreases over time. The experiments also show a loss of surface reactivity at 310°C and a regeneration of surface reactivity with increased temperature up to 350°C. Concentrations of CO₂ and H₂ used in the experiments simulate periodic, localized and dynamic conditions occurring within the seafloor during and immediately following magmatic diking events. High concentrations of CO₂ and H₂ may be generated by dike injection accompanied by exsolution of CO₂ and reaction of dissolved H₂O with FeO in the magma to form H₂. The experiments described here examine how the ephemeral formation of an H₂–CO₂-rich vapor phase within seafloor hydrothermal systems may supply reactants for abiotic organic synthesis reactions. These experiments show that the presence of specific minerals can promote the abiotic synthesis of simple organic molecules from common inorganic reactants such H₂O, CO₂ and H₂ under geologically realistic conditions.     

浙西康山可燃有机岩矿脉的实质与成因

对浙江西部康山可燃有机岩矿脉的镜下观察与煤，石油沥青的热模拟产物的对比，稳定碳同位素，生物标志物，微量元素的分析对比，以及大量陆源碎屑物和自生矿的的存在，确定这种可燃有机岩矿脉的实质是腐泥质盆煤－无烟煤，而非石油衍生物，不属于经过运移的石油沥青；综合区域地质条件，矿脉产状和分析数据对比，再次确认其来源为下寒武统荷塘组腐泥煤。     

新一轮土地整治规划分区研究——以山东省肥城市为例

进行土地整治分区是编制土地整治规划的重要内容之一。以往的土地整理复垦开发分区已不能适应当前土地整治工作管理的需要。该文以山东省肥城市为例,提出了土地整治分区的原则和方法,从宏观尺度上,运用聚类分析法进行土地整治综合分区,从中观尺度上,运用叠图法进行土地整治功能分区,并指出了不同区域土地整治的方向和重点。     

贵州-湖南黑色岩系的有机碳和有机硫特征及成因意义

黑色岩系是多种元素的富集体,其中常产出许多大型超大型矿床,越来越受到国内外地学界的重视。然而,关于黑色岩系的成因一直是有争议的问题。对贵州—湖南地区下寒武统黑色岩系有机碳和有机硫的研究,表明黑色岩系的有机碳和有机硫含量较高,因而本文认为黑色岩系形成于低能、缺氧还原的浅水台地边缘环境。     

Biomagnification in marine systems: the perspective of an ecologist

Biomagnification is the process where xenobiotic substances are transferred from food to an organism resulting in higher concentrations compared with the source. It is widely believed that this is a general phenomenon for marine food webs. An analysis of 148 papers with biomagnification in the title shows that under half show biomagnification. Of studies on metals only organic mercury shows biomagnification and most metals are regulated and excreted and do not biomagnify. Of the studies on organic compounds 67% claimed to show biomagnification. However, bioconcentration (uptake from the surrounding water) is the most usual way that organic compounds are accumulated in organisms from invertebrates to and including fish. Only in sea-birds and marine mammals is food intake the major route and where biomagnification can be clearly shown. Body concentrations of organic compounds vary with lipid content and thus in order to compare across species normalisation to uniform lipid content should be done. Yet often this is not done so data purporting to show biomagnification merely relate to differing lipid content in the different species studied. Finally suggestions are made as to how data can be collected to better interpret the process of biomagnification in marine food webs.     

健康水生态系统的退化及其修复——理论、技术及应用

由于人口增加和工农业生产的发展,人类赖以生存的淡水生态系统日益退化,特别是富营养化问题,已严重威胁社会经济的持续发展和人类健康,如何在强污染负荷下修复水生态系统具有重大理论和现实意义,本文总结了自1990年以来在淡水湖泊中进行的物理生态工程（Physico-Ecological Enginnering ,PEEN)实验研究实践,主要结论O 为：（1）地表水环境治理的主要目标是修复为稳定健康的水生态系统;（2）主要方法是与污染源治理相结合实践物理生态工程IPEEN）和生物环保产业（Bio-Environmental Enterprise,BEE);(3)实现目标的主要途径是星火燎原,从局部到大范围乃至全流程;（4）实现目标的主要关键是抓住四个环节（4M）;高等水生植物（Macrophyte),宏观颔生学（Macro-bioimitation), 微生物（Microorganism),及管理（Management).(5)山清水秀,人杰地灵,社会经济生态协调发展的美好未来有可能在不远的将来实现。     

Multi-residues of organic pollutants in surface sediments from littoral areas of the Yellow Sea, China

Concentrations of all studied organic pollutants, except for DDTs, were greatest at sites in Dalian Bay, where surface sediment concentrations of PHCs, PAHs, PCBs and DDTs exceeded the corresponding ERL values. The sum concentration of DDTs was greatest in Haizhou Bay exceeding the related ERM value. In terms of compositions of PAHs and PAEs, the predominant components were the MMW and HMW compounds, DBP and DEHP, respectively. The main degradation product of p,p'-DDT was p,p'-DDD at most sampling sites. The principal sources of PAHs and DDTs involved various pyrolytic processes (i.e., combustion of biomass and vehicle exhaust), and application of technical DDT (in the form of impurity or raw material), and a mixture of technical DDT and technical dicofol. Moreover, the coastal site with greatest potential ecological risk from total PAHs was located in Dalian Bay, while the littoral areas of Dalian Bay, two harbor cities (Yantai-Weihai), Jiaozhou Bay, and Haizhou Bay, had relatively high potential risk from DDTs, especially in Haizhou Bay.     

滑坡防治工程的现状与发展展望

自然产生的和人类工程活动引起的滑坡灾害在我国都相当严重。滑坡防治也日益成为工程研究的热点之一。本文首先评述了四类滑坡治理措施的现状及技术方面的进展,进而讨论了恰当的滑坡防治工程措施的选择依据和设计施工程序,最后简要展望了发展趋势。     

石油污染场地浅层地下水MNA原位修复潜能及微生物降解效益评估

监测式自然衰减（MNA）能够高效低耗地原位修复石油污染地下水的场地,微生物对污染物的降解对MNA过程起到了重要作用。在分析东北石油污染场地地下水中总石油烃（TPH）、电子受体的质量浓度分布和变化规律基础上,划分了微生物功能区。采用溶质通量计算法,对MNA原位修复的潜能及其微生物降解效果进行了评估。结果显示,场地微生物降解正在发生,利用的电子受体不同,划分为Mn、Fe和SO^2-₄还原区。污染通量模型计算显示：上游地区微生物降解强度不断增强,下游地区微生物降解强度不断降低。监测期内石油烃总量降低了394 kg,微生物降解为自然衰减过程中的主要作用,其贡献率为64%~93%,每个通量断面内微生物降解率为0.18~0.73 kg/d。由此可以证明,MNA可以有效地修复地下水中的石油污染。