硅酸盐熔体的体积行为

通过研究硅酸盐熔体的氧平均体积,并与硅酸盐玻璃相对比,提出硅酸盐熔体的体积可分为两部分,即硅-氧骨架部分和阳离子部分,根据氧平均体积变化规律,得出硅-氧骨架部分的体积基本不随温度变化,硅酸盐熔体的体积膨胀主要是由于“氧化物”部分的局部膨胀所致,进一步提出O~(2-)半径基本不变,而主要是阳离子半径变化,并讨论了膨胀的机制。     

地球各圈层氧离子平均体积守恒规律的发现

在氧化物和硅酸盐晶体结构中,氧离子作某种形式的堆垒,金属阳离子则充填于堆垒的空隙之中。氧离子体积比阳离子体积大得多,而且数量也多。所以,作为“实体球”而言,氧的总体积比阳离子总体积是25:1～30:1。也就是说,实体体积中有95％是由氧占着。假若我们把整个晶体的体积都归属于氧,于是就可以算出每个氧离子平均体积Vo(简称氧平均体积)。这是一个很有意义的概念。叶大年在开展国家科学基金项目“硅酸岩矿物和岩石中某些统计结晶化学规律的研究”时,将这个概念引入结构光性矿物学和材料学的研究之中,揭示出一些定量的规律。最近,本文作者对氧平均体积的研究取得了很大进展,说明氧     

架状硅酸盐的氧平均体积

架状硅酸盐的氧平均体积与晶体结构有如下关系:V_o=a+bf(s)。对于每种结构类型而言,a和b是常数。f(s)是结构函数,它取决于离子半径、离子电价以及类质同象替代关系。文中给出了长石型、白榴石型、鳞石英型以及β石英型架状硅酸盐的V_0与结构函数之间的定量关系。沸石中虽含有大量水,但其V_o并未增大,平均值为22.25A~3,标准方差σ_(n-1)=0.82A~3,与石英玻璃V_o值近于相等。     

The genesis of pyroclasts and the mechanism of submarine eruption of Naozhou Island in Guangdong,South ChinaSCIEI北大核心CSCD

水下火山喷发作用机制不同于陆地环境喷发,随着水参与程度的变化,喷发机制趋向复杂。本文以雷琼火山群的湛江硇洲岛作为研究对象,聚焦浅海火山产物的判断依据和水下火山喷发机制。硇洲岛是我国最大的第四纪火山岛,其上的那晏湾剖面保留了完整的火山喷发堆积序列。在那晏湾剖面的凝灰岩中,主要有三类火山成因的大粒径原生碎屑(2-5mm):塑变熔岩碎屑、碎玄玻璃及玄武玻璃,推断为不同程度水-岩浆相互作用的产物,根据水的参与程度大致排序为:碎玄玻璃>玄武玻璃>塑变熔岩碎屑。通过对硇洲岛水-火山作用机制研究,发现水-岩浆混合质量比(Mwater/Mmelt)是控制爆炸强度和火山碎屑粒度的关键因素。火山喷发序列分析表明,硇洲岛的喷发过程总体可分为三期,早期是冰岛苏特塞式喷发的浅水环境蒸汽爆炸与“火喷泉”喷发;中期过渡转为“火喷泉”喷发,伴随陆上的射汽岩浆喷发;最终以岩浆溢流式喷发结束。     

结构矿物学的新成果

四、矿物大孔洞骨架结构的分类 (接上期) 矿物中大孔洞骨架构造首先是在沸石族矿物中发现的。沸石是一类架状构造铝硅酸盐,具有很空旷的硅氧骨架,结构中有许多孔径均匀的孔道和内表面很大的孔穴,其中含有水分子,这些水分子在加热时可以被赶出,硅氧骨架并不破坏,在合适的湿度下水分子也可重新进入骨架,此种水称为“沸石水”。结构的孔道和孔穴中还可存在有一些阳离子,这些阳离子常是电价较低、半径较大的碱金属或碱土金属离子,结构中的这些离子可以与矿物所处的溶液中的离子发生交换,因此称为“交换性阳离子”。由于沸石结构具有上述特点,它可以作为吸附剂、分离剂(分子筛)、催化剂、离子交换剂而被应用,工业上称之为分子筛。由于沸石分子筛具有很高的活性、较好的选择性和热稳定性,使得沸石分子筛在化工、石油、冶金、建材、医药等方面得到广泛的应用。一般所说的分子筛就是指的沸石分子筛。     

Zn2+改性丝光沸石对甲基橙的吸附性能研究

采用盐熔融法,将Zn2+交换丝光沸石分子筛制备Zn2+改性丝光沸石吸附材料。通过该材料对甲基橙的吸附动力学和吸附热力学研究,了解其吸附机理。研究结果表明:Zn2+改性丝光沸石对甲基橙的吸附动力学可用拟二级动力学方程来描述,计算值与试验值吻合较好,相关系数达到0.99;Zn2+改性丝光沸石对甲基橙的吸附等温线均符合Langmuir和Freundlich方程,室温下相关系数均大于0.9。根据不同温度下的热力学平衡常数,推算出Zn2+改性丝光沸石对甲基橙的吸附吉布斯自由能变ΔG0<0,吸附焓变ΔH0>0,表明吸附为自发的吸附过程,升温有利于吸附的进行,且吸附过程主要是物理吸附。     

陕北非饱和重塑红土渗透特性试验研究

以实测土水特征曲线为基础,采用 Van Genuchten 模型,详细研究了干密度和体积含水量对非饱和保德组红土渗透特性的影响。研究表明:不同干密度下,在半对数坐标系中,非饱和保德组红土渗透系数与体积含水量呈现出近似直线关系,非饱和保德组红土渗透系数随体积含水量的增大而单调加速增大,且密实状态非饱和保德组红土渗透系数对体积含水量的变化比较敏感。不同干密度下,在半对数坐标系中,非饱和保德组红土渗透系数与基质吸力之间呈现出指数函数关系,且非饱和保德组红土渗透系数随基质吸力的增大而减小,当土体干密度较大时,非饱和保德组红土渗透系数随基质吸力的增大变化较大,同样表明密实状态非饱和保德组红土的渗透系数对干密度的变化比较敏感。     

陕北非饱和重塑红土渗透特性试验研究

以实测土水特征曲线为基础,采用Van Genuchten模型,详细研究了干密度和体积含水量对非饱和保德组红土渗透特性的影响。研究表明:不同干密度下,在半对数坐标系中,非饱和保德组红土渗透系数与体积含水量呈现出近似直线关系,非饱和保德组红土渗透系数随体积含水量的增大而单调加速增大,且密实状态非饱和保德组红土渗透系数对体积含水量的变化比较敏感。不同干密度下,在半对数坐标系中,非饱和保德组红土渗透系数与基质吸力之间呈现出指数函数关系,且非饱和保德组红土渗透系数随基质吸力的增大而减小,当土体干密度较大时,非饱和保德组红土渗透系数随基质吸力的增大变化较大,同样表明密实状态非饱和保德组红土的渗透系数对干密度的变化比较敏感。     

天然沸石负载二氧化钛光催化剂的制备与性能研究

以钛酸丁酯为钛源，天然沸石为载体，用溶胶．凝胶法制备了天然沸石负载TiO2光催化剂，用紫外可见吸收光谱、比表面积、红外光谱和X射线衍射等分析技术对沸石负载TiO2光催化剂进行了表征，以甲基橙为目标降解染料，考察了TiO2负载量、催化剂用量、热处理温度等不同条件下催化剂的光催化活性，结果表明，用天然沸石为载体所制得的TiO2光催化剂对于甲基橙具有较好的光催化降解效果。     

基于煤层气井排采数据的储层含气量动态反演研究

煤储层含气量是煤层气开发的核心参数,但实测煤储层含气量与煤储层的真实含气量之间往往存在误差。基于窑街矿区海石湾井田煤层气井不同时段的产气量,以煤储层含气量“定体积”降低为基础,反演煤储层实时含气量,研究煤层气井排采过程煤储层实时含气量的变化规律。结果表明:煤储层含气量随排采时间呈线性下降趋势,不同步长煤层气井产气量与煤储层含气量降低幅度一致,遵循“定体积”产气特征,即煤层气单井产气量是煤基质“定体积”产出;煤层气井的产气量与含气量降低速率有关,而与煤储层原始含气量无关。煤储层为隔水层,水力压裂难以改变煤基微孔隙通道的结合水状态,CH₄产出过程受水–煤界面作用控制,煤层气产出是“CH₄·煤·水”三相界面传质作用的结果,水–煤界面作用中水的湍动提供并传递能量,激励块煤中CH₄解吸与产出。      

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Late Wuchiapingian (Late Dzhulfian,early Late Permian) limestone olistolites within the Tertiary flysch of Glypia Unit (Mount Parnon,central–eastern Peloponnesus,Greece)

Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.     

PALEONTOLOGY

正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)     

GEOCHEMICAL EXPLORATION

正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.)     

MICROPALAEONTOLOGY

正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.)     

PETROLOGY

正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus.,     

ENVIRONMENTAL GEOLOGY

正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an