The Earth as a multiscale quantum-mechanical system

Major features of the Earth's structure and dynamics originate in the contrast between the rigidity of SiO bonds and the softness of SiOSi linkages. Because this contrast results from orbital hybridization, a real understanding of bonding relies on ab initio quantum-mechanical principles. As investigated with first-principles interatomic potentials, the α–β transitions of SiO₂ polymorphs illustrate how soft SiOSi linkages give rise to dynamical structures at rather low temperatures and yield the low melting temperatures of SiO₂-rich minerals that are at the roots of SiO₂ enrichment in magmatic differentiation. The increasing concentration of alkalis throughout this process is another aspect that must also be studied in terms of molecular orbitals in relation with the presence of aluminum in tetrahedral coordination. Finally, calculations of noble gas solubility show that some important features can be treated with “hybrid” calculations when, in addition to quantum-mechanical effects, the energy needed to create a cavity in the silicate melt is dealt with in a classical manner.     

Influence of stock origin and environmental conditions on the survival and growth of juvenile freshwater pearl mussels (Margaritifera margaritifera) in a cross-exposure experiment

The freshwater pearl mussel (Margaritifera margaritifera) is a highly specialized and sensitive freshwater bivalve, whose survival in the juvenile phase is indicative of high quality habitats. This contribution investigates the use of juvenile freshwater pearl mussels as bioindicators, considering the influence of mussel stock and study stream conditions on juvenile performance, as described by survival and growth rates. A standardized cross experiment was carried out investigating juvenile performance in four different pearl mussel stocks originating from the Rhine, Danube and Elbe drainages, representing distinct genetic conservation units. The juveniles were exposed in five study streams which were selected to integrate pearl mussel streams with different water qualities and recruitment status of the mussel population. Per study stream, five standard mesh cages containing an equal number of 20 (10 × 2) juvenile pearl mussels per stock in separate chambers were installed. Survival and growth rates of juveniles were checked after three months (i.e. before their first winter) and after nine months (i.e. after their first winter). Mussel stock and study stream conditions significantly influenced juvenile performance. Growth rates were determined by study stream conditions and increased with stream water temperature, organic carbon and C/N ratios. Survival rates varied stock-specifically, indicating different levels of local adaptation to their native streams. Due to the detection of stream-specific differences in juvenile performance, freshwater pearl mussels appear suitable as bioindicators. However, a careful consideration of stock-specificity is necessary to avoid false interpretation of bioindication results. The comparison of stock-specific survival in native versus non-native streams implicates that exposure of juveniles outside their native habitats is able to increase breeding success or else serve for risk spreading in breeding programs.     

刺参（Apostichopus japonicus）野生及两代选育群体间遗传变异的微卫星标记研究

应用微卫星DNA技术对野生刺参和两代选育刺参群体遗传多样性进行了研究。9对微卫星引物在三个刺参群体中共扩增获得43个等位基因,每个微卫星座位检测到的等位基因数为2—7个。三个群体的观测杂合度的平均值分别为0．6556、0．6704和0．6148,多态信息含量平均值分别为0．6654、0．5929和0．5275。结果表明...     

纵向岭谷区地表格局的生态效应及其区域分异

中国西南纵向高耸山岭与深切河谷并列排布的特殊地表格局对该区自然环境与生态地理区域分异的效应明显。利用纵向岭谷区1:5 万DEM数据、建站以来至2010 的气象观测数据、水文观测资料、MOD13 与MOD17 的NDVI与NPP产品以及1:100 万植被类型数据等,选取地表大气水汽含量、降水量、干湿指数、地表径流等水分指标,平均气温、年积温等温度指标以及太阳总辐射等热量指标,基于ANUSPLIN样条函数、GIS空间分析、小波分析、景观格局分析等方法,分析该区水热格局、生态系统结构与功能的地域分异特征及其主控因子,揭示地表格局对生态地理要素区域分异的效应。结果表明：受地表格局的影响,纵向岭谷区的水分、温度与热量都表现出明显的沿纬线方向间断式差异和经线方向连续式延伸的分布特征,纵向山系与河谷对地表主要自然物质和能量输送具有南北向通道作用和扩散效应以及东西向阻隔作用和屏障效应;特殊地表格局对植被景观多样性、生态系统结构与功能的空间格局产生重要影响,是植被景观多样性与生态系统空间分布的主要控制因子;小波方差分析反映了环境因子以及NDVI、NPP的空间各向异性,而小波一致性分析揭示了NDVI与NPP空间分布的控制因子,及其控制程度的定量关系。纵向岭谷特殊地表格局是该区生态地理区域分异的主要影响因素,在地带性规律与以“通道—阻隔”作用为主要特征的非地带性规律共同作用下,形成了纵向岭谷区生态地理区域系统的特殊空间特征。     

三种不同生境的桐花树种群的遗传多样性和遗传分化

采用垂直板型聚丙烯酰胺凝胶电泳测定了三种不同生境的桐花树（Ａｅｇｉｃｅｒａｓ ｃｏｒ ｎｉｃｕｌａｔｕｍ）种群的遗传多样性和遗传分化。桐花树和种群水平都维持有较高的遗传变异性,观察杂合度分别为０．２５２和０．２４４。期望杂合度分别为０．２６６、０．２４０。种群间遗传分化系数为０．１２７,表明总的遗传变异中有１２．７％来自种群间,种群间遗传距离和遗传一致度均值分别为０．０６０和０．９６４,基因流畅,Ｎｍ＝２．１８７。     

五台山区太古宙铁建造型金矿的成矿年龄

五台山区铁建造金矿是我国最重要的太古宙铁建造型金矿,产于五台山绿岩带铁建造中,矿石石英40Ar／39Ar同位素等时线年龄为2416±64Ma和2317±63Ma,是迄今为止我国最老的铁建造金矿成矿年龄,并得到区域重大地质事件同位素年龄和矿床地质地球化学特征的合理解释,成矿作用发生在区域变质变形峰期之后,相当于五台晚期或吕梁早期。主成矿期包含两个主成矿阶段,第一阶段成矿作用发生于2416±64Ma,第二阶段成矿作用发生于2317±63Ma。     

内蒙古蛤蟆沟林场中生代火山岩浆演化及成因探讨

岩石地球化学特征研究表明,蛤蟆沟林场地区中生代火山岩属于钙碱性火山岩系列,岩浆演化序列为中性→酸性→中性→酸性.火山岩化学成分变化以岩浆结晶分异占主导地位,岩浆分异较好.火山岩属于板内造山带产物,岩浆来源于壳源.     

横断山区干旱河谷植被类型

横断山区干旱河谷植被,按植物群落的生态外貌、种类组成与结构特点,可分为4个类型(即:稀树灌木草丛,肉质刺灌丛,扭曲云南松疏林,小叶刺灌丛)15个群落。按干旱河谷的区域分异、水热状况、山地植被垂直带和利用方向,将本区干旱河谷分为4个类型(即:干热、干暖、干温、干凉)7个区。     

西南山地灾链的区域分异

我国西南山区各种山地灾害（暴雨、崩塌、滑坡、泥石流与洪水）往往彼此相伴生，而成串联式链状结构。以泥石流为主害灾种的灾链演变有五个阶段。据灾链演化区域分异性，分出四个大区九个灾区。