Hydrogen Isotopes of Glassy and Phyllosilicate Spherules in Al Rais (CR) and Orgueil (CI) Chondrites

The hydroxyl in phyllosilicate minerals is the most common occurrence of water in primitive meteorites. Direct hydrogen isotopic analysis of this water component using an ion microprobe has been made in some glassy or phyllosilicate spherules from the Al Rais (CR) and Orgueil (CI) chondrites. The spherules from Al Rais show large deuterium excesses (δD = +200 -+800‰) relative to terrestrial standards, whereas deuterium-enrichments in the spherules from Orgueil are much smaller (δD = +40 - +130‰). The phyllosilicate spherules are products of     

保险粉-H2O2对棉布脱色的实验研究

常用的次氯酸脱色法是在酸性条件下用次氯酸或次氯酸钠对棉布进行处理。实验研究用保险粉-H2O2多段脱色法对棉布进行脱色。保险粉处理段是在保险粉溶液中添加NaHCO3作缓冲剂，加热沸腾40min对棉布进行处理，H2O2则是在碱性H2O2溶液中，添加NaSiO3作添加剂，使棉布加热沸腾30min。与次氯酸脱色法相比，不仅脱色后的棉布强度没有减弱，而且脱色效果能达到或接近次氯酸法的脱色效果。同时脱色后的废水中不含有机氯化物，避免了致癌物质的产生。     

Promotive effect of se on the growth and antioxidation of a blue-green algaSpirulina maxima

Cultures of a blue-green algaSpirulina maxima (Setch. et Gard.) Geitler with various concentrations of Se in Zarrouk's medium showed that not higher than 40 mg/L Se could promote its growth. The present experiments showed thatS. maxima grown under normal conditions, has an oxidant stress defence system for hydrogen peroxide (H₂O₂) removal, which is the Halliwell-Asada pathway. When 4 to 20 mg/L Se was added to the algal medium, this pathway was replaced by a so-called Sestressed pathway containing GSH peroxidase (GSH-POD). As a result of the occurrence of both higher activity of GSH-POD and lower levels of hydroxyl radical (OH·), the Se-stressed pathway scavenged H₂O₂ so effectively that the growth ofS. maxima was promoted by 4 to 20 mg/L Se. While GSH-POD activity of the alga disappeared at 40 mg/L Se, the recovery of ascorbate peroxidase was observed. The lower levels of ascorbic acid and GSH made the Halliwell-Asada pathway for scavenging H₂O₂ less effective, while the highest activity of catalase might be responsible in part for the H₂O₂ removal, causing the level of OH· inS. maxima grown at 40 mg/L Se to be much higher than the OH· level in this alga grown at 4 to 20 mg/L Se, but lower than that in the control. The OH· level changes caused the growth ofS. maxima cultured at 40 mg/L Se to increase slightly to close to that of the control.     

HYDROGEN ION CONCENTRATION IN RAIN WATER

Continuous measurements of pH precipitation falling from cumulus clouds in semi-arid region(Colorado,USA),and in wet temperate zone(Bologna,Italy)were made.In Colorado the pHwas constant at 7.3 for a period of time,and later changed to 7.0 and remained constant at thisvalue during the remainder of the storm.In Italy the pH fluctuated continuously between theapproximate values of 5.7 and 6.4 during the storm.The changes in hydrogen ion concentrationreflect the chemical composition of cloud condensation nuclei and of scavenged aerosol particles andgases presented in the region.     

Stepwise chemical degradation of immature S-rich kerogens from Vena del Gesso (Italy)

Stepwise chemical degradation involving cleavage of ester bonds (KOH/MeOH), sulfide and remaining ester bonds (Li/EtNH₂), ether bonds (HI/LiAlH₄) and sub-units linked to aromatic moieties (RuO₄) has been carried out on the kerogens of two immature sulfur-rich marls (IV-1.4 and 1.8, TOC ca. 1.5%) from evaporitic cycle IV of the Gesosso-solfifera Formation (Messinian, Vena del Gesso, Italy). Up to 80% of the organic matter was converted to solvent-soluble material, with the greatest proportion released by Li/EtNH₂. The majority by far of the extracts comprises polar macromolecular material which is thought to correspond to high molecular weight sub-units of the kerogen. Quantification of the small amounts (<1%) of the released GC-amenable components indicates that diagenetic sulfurization was more important in the case of kerogen IV-1.4 but that the extent of oxygen sequestration was similar in both cases; the distributions of biomarkers released by ether cleavage of the desulfurized residue and polar fraction showed differences which reveal heterogeneity in the building blocks making up different macromolecular fractions.     

辽宁二道沟金矿床稳定同位素地球化学研究

对石曲中流体包裹体的氢氧同位素研究表明,二道沟金矿床含矿热水溶液的δＤ为－７１‰－－１０２．５‰,δ＾１８ＯＨ２Ｏ为１．３５‰－６．７‰,它们落入２００与３００℃时大气降水与火山岩发生水岩交换的演化线所夹的区域内,表明热水溶液主要来自源于大气降水的地下水,而不直接来源于岩浆热液。     

Abundance and Partitioning of OH in a High-pressure Magmatic System: Megacrysts from the Monastery Kimberlite, South Africa

Concentrations of OH, and major and trace elements were determinedin a suite of mantle-derived megacrysts that represent the crystallizationproducts of a kimberlite-like magma at     

锰结核矿物及其原位复合材料吸氢性能的初步研究

采自东太平洋中国开辟区的锰结核，主矿物相为钡镁锰矿、钠水锰矿，以及属XRD隐晶质的针铁矿与四方纤铁矿，部分矿物相结构特征与人工合成的纲伙碳管十分相似。在室温中压下采用等容压差法测量了锰结核的气态贮氢能力，测得锰结核样品的吸氢量为0.31%。以乙炔为碳源，在750℃下采用气相沉积法直接在锰结核上成功地催化制备出多壁纳米碳管和纳米碳纤维，同样条件测试这种矿物碳管原位复合材料的吸氢性能，其吸氢能力达到1％左右。保持锰结核矿物结晶结构在加热脱水过程中的稳定性，对提高其贮氢能力至关重要。     

200℃水热条件下金属铂的氢渗透常数测定

本文采用氢感应法，测定低温水热条件下Pt的H2渗透常数k，并可根据H2渗透来计算实验体系的氧逸度。这种方法无需依赖H2在氧缓冲体系与实验体系间平衡状态的到达，但要求有精确的氢渗透常数。本研究在200℃，NNO及HM氧缓冲的实验条件下，通过测定氢感应体系中淬火溶液Cl^-浓度的变化，计算求得Pt的H2渗透常数k为10^-13～10^-14数量级。并讨论了在实验及数据处理过程中对H2渗透常数k可能带来的误差及影响因素。