基于探针气体吸附等温线的矿物材料表征技术:Ⅱ.多孔材料的孔隙结构

含纳米孔的天然矿物岩石材料的吸附和催化性能对于表生地球化学过程、材料加工、应用及煤炭开发利用等方面均有着重要意义。本文对比分析了各种纳米孔表征技术,重点介绍了基于吸附等温线的纳米孔研究方法。对三个典型样品等温线数据的模型计算表明,应根据材料中孔的形态(平行板状孔、球形孔和圆柱形孔)选择模型,不同类型孔所对应的计算方法和参数有很大差别。表征材料表面能量均匀的样品可首先考虑采用DFT法;HK法一般只作为定性研究方法,BJH方法受样品本身性质参数的影响较小,且计算简单,可广泛应用于介孔材料的孔径分布的表征。     

鄂尔多斯盆地基底结构及早期沉积盖层演化

鄂尔多斯盆地基底主要形成于太古宙—古元古代,岩石组成极为复杂,大多经历了较强的区域变质作用,变质程度一般达到了(高)角闪岩相—麻粒岩相,属变质程度较深的区域变质岩系,主要是各种片岩、片麻岩及变粒岩、石英岩、大理石及花岗片麻岩等;基底结构具有较为明显的分区特征,可划分为北部、西北部及中南部三个大区,走向总体以北东向为主;从演化过程来看,鄂尔多斯盆地基底是华北克拉通形成过程中的太古宙微陆块之一,古元古代末可能是其与华北拼合为一体的关键时期。早期沉积盖层主要经历了长城纪陆内裂陷、蓟县纪边部沉降、青白口纪—南华纪整体隆升和震旦纪边缘拗陷4个演化阶段,沉积环境总体以海相为主,晚期局部具陆相特征,不同时期的沉积物特征有较大差异,可能主要受构造、气候环境的共同制约;早期沉积盖层整体上受基底结构和构造控制明显,越早期影响越大;盆地西南边缘一直是最活跃的构造沉降区,基底构造所处位置特殊可能是其最主要的原因。     

Petrogenesis and Tectonic Implications of the Latest Cretaceous Intrusive Rocks from the Eastern Gangdese Belt, Southeast Tibet

The latest Cretaceous magmatic activity in the eastern segment of the Lhasa terrane provides important insights for tracking the magma source and geodynamic setting of the eastern Gangdese batholith, eastward of eastern Himalayan Syntaxis. Detailed petrological, geochemical and geochronological studies of the intrusive rocks (monzodiorites and granodiorites) of the eastern Gangdese batholith are presented with monzodiorites and granodiorites giving zircon U–Pb crystallization dates of 70–66 Ma and 71–66 Ma with εHf(t) values of ?4.8 to +6.2 and ?1.9 to +5.3, respectively. These rocks are metaluminous to weakly peraluminous I-type granites showing geochemically arc-related features of enrichment in LREEs and some LILEs, e.g., Rb, Th, and U, and depletion in HREEs and some HFSEs, e.g., Nb, Ta, and Ti. The rocks are interpreted to be derived from partial melting of mantle material and juvenile crust, respectively, which are proposed to be triggered by Neo-Tethyan slab rollback during northward subduction, with both experiencing ancient crustal contamination. The studied intrusive rocks formed in a transitional geodynamic setting caused by Neo-Tethyan oceanic flat subduction to slab rollback beneath the eastern Gangdese belt during the latest Cretaceous.     

Distribution of gold and rhenium between nickel-iron and silicate melts: implications for the abundance of siderophile elements on the Earth and Moon

The distribution equilibrium of Au and Re between nickel-iron and basaltic melts was studied at 1400–1600°C, using radioactive tracers. Metal/silicate distribution coefficients were 1–3 orders of magnitude higher than earlier estimates, as follows. Mauna Loa basalt—Fe₁₀Ni₉₀: D_Au = 3.3 × 10⁴, D_Re = (2.4?89) × 10⁴. Gorda Ridge basalt—Fe₁₀Ni₉₀: D_Au = (18?75) × 10⁴. Synthetic lunar basalt—Fe₇₀ Ni₃₀: D_Au≥ 2 × 10⁴, D_Re ≥ 2 × 10³. The experimental ΔG₁₈₀₀^° for the distribution of Au between nickel-iron and Mauna Loa basalt is ?40 kcal/mole, compared to a calculated value of about ?110 kcal/mole for a reaction involving simple Au³⁺ ions. Presumably the difference represents stabilization of Au(III) by complex formation with ligands such as Cl^?, H₂O, etc.Gold abundances in lunar basalts are roughly consistent with the measured D_Au, but those in terrestrial basalts are two orders of magnitude too high. This discrepancy may reflect complexing by volatiles in the Earth's upper lithosphere, as well as oxidative destruction of metal in the final stages of accretion. In the absence of a metal phase, siderophile trace elements would remain trapped in the upper mantle and crust.     

Development of a new method for efficiently calculating of evaporation from the phreatic aquifer in variably saturated flow modeling

In this paper, we proposed a new method that has been developed based on the surface soil moisture content (SSMC) to more efficiently calculate the groundwater evaporation in variably saturated flow modeling. In this method, the empirical formula to calculate evaporation was modified and the value of the formula varies from zero to one as a closed interval. In addition, the simulation code for calculating the groundwater evaporation based on the SSMC method was incorporated into the EOS9 module of Tough2, a variably saturated flow modeling code. Finally, two numerical tests and a case simulation were conducted to verify the feasibility and accuracy of the SSMC method. Simulation results indicate that the SSMC method is capable of appropriately simulating the characteristics of water flow in vadose zone and the amount of evaporation with the variable water table. And such results are in coincidence with the value calculated by the logistic function method, and fit well with the measured data globally rather than locally.     

含砾石土壤降雨入渗过程模拟

在室内模拟降雨试验的基础上,利用多重相互作用连续体(MINC)组件,对含砾石土壤降雨入渗过程进行了数值模拟,以期深入理解含砾石土壤中的水土过程.研究结果表明,土壤中砾石的存在能够导致土壤水分饱和度增加,使得土壤总入渗量以及降雨入渗深度降低.含砾石土壤中存在一个陡的湿润锋面,在湿润锋面上土壤水分饱和度急剧下降.MINC组件可以很好地模拟含砾石土壤降雨入渗过程,其对含砾石土壤湿润锋和土壤含水率变化的模拟值与实测值吻合较好.降雨期间土壤水分饱和度沿土壤剖面的变化可用来解释含砾石土壤降雨入渗深度降低的原因.     

论中国的矿产资源可持续发展战略

本文论述了我国矿产资源可持续发展战略。全文共分５个部分：１．可持续发展战略的理论考查。通过对人类历史上可持续发展思想的回顾,阐述了当代可持续发展理论的定义、内容和意义;２．我国矿产资源的总体特征;３．另矿产资源可持续发展战略目标。提出了我国矿产资源可持续发展战略目标：最大限度地满足国民经济发展对矿产资源的需求,不断提高矿产资源利用水平,建立有效的管理与保护体系,保护环境;４．矿产资源可持续发展战略     

山西宁武地区高山湖泊全新世湖相地层划分及干海组的建立

通过山西宁武地区高山湖泊湖相沉积地层的浅井挖掘,在天池湖泊群一带发现了厚度大于6m的以草炭、泥炭、粘土及砂层为主的湖相沉积物。根据实测的干海、天池和琵琶海3条剖面,将分布于高山湖盆区内的湖相地层划分为12层,层序地层显示出以干海为代表的古湖泊由浅湖→滨湖→沼泽的演化趋势。湖相沉积的14C法测年结果为10950～260aBP,ESR法年龄测定结果为(9±3～8±1)ka,这表明高山湖盆内湖相沉积的形成时代为全新世。根据沉积相、岩相组合等特征,结合同位素测年、孢粉分析、微体古生物鉴定等资料,首次建立了山西宁武地区高山湖泊全新世湖相沉积地层序列,并将该套地层命名为干海组。     

山东平邑—蒙阴地区古近纪地层时代讨论

通过对山东平邑—蒙阴地区古近纪地层的野外地质调查和实测剖面,对分布于该区内的古近系进行了详细的研究和划分,提供了新的ESR测年数据,并结合生物地层序列确定了该区古近系的地层顺序为：古近系渐新统汶东组（E3w）、古近系上始新统大汶口组（E23d）、古近系中始新统朱家沟组（E22z）、古近系下始新统常路组（E21c）、古近系上古新统卞桥组（E12b）和古近系下古新统固城组（E11g）。为华北地区乃至全国古近系的研究与划分提供了重要依据。