长江与黄河入海活性硅输送规律及变化趋势

根据长江与黄河各一个完整水文年的调查数据,并结合历史资料分析了我国这两条大型河流活性硅((RSi,RSi=溶解硅(DSi)+生物硅(BSi))的入海通量及长时间序列的变化规律与影响因素.结果表明,长江与黄河RSi的组成存在显著的差异,二者水体中BSi/RSi的平均比值分别为0.22和0.49;黄河DSi的年平均浓度为长江的74%,而BSi年平均浓度却是长江的3倍.黄河水体中相对较高的BSi浓度反映了黄河流域水体浑浊度与土壤侵蚀程度较高,源自黄土高原高的泥沙输送量是导致黄河水体中BSi浓度较长江高的主要原因.长江与黄河下游RSi通量在丰水期、平水期与枯水期的比值分别为5.3∶3.1∶1.6与3.8∶3.4∶2.8,长江半数以上的RSi入海通量是在丰水期输出的,而黄河在3个时期的差异不明显.相比于径流的变化,1958-2014年间长江DSi通量变化主要是由DSi浓度的变化引起的,流域气候变化(如温度变化)是其浓度及其通量年代际变化的重要原因;而黄河1985-2001年间DSi通量下降是由于径流量与DSi浓度降低的双重原因引起的.气候变化,特别是温度的变化会对流域硅的风化速率与硅的产出产生重要影响,但其具体的影响有待进一步揭示.     

新疆农田投入化肥时空变化及趋势分析

通过研究相关统计资料对新疆农田化肥投入在时间和空间上的变化进行了分析。结果表明：1980年以来新疆农田投入化肥分为稳步上升、快速增长和徘徊波动三个阶段。新疆农田投入化肥在空间上的变化为：地区间分布不平衡,南疆与北疆、棉区与粮区、兵团与地方之间差异明显。在此基础上对未来新疆化肥资源的施用趋势进行了讨论。     

金川铜镍硫化物矿床深熔-就地成矿作用过程研究

文章通过研究矿石冶炼过程中矿物种类、含量、物理化学性质、结晶形态、嵌布特征、颗粒大小和生成环境以及矿物在高温条件下的物理化学反应等，并使之与铜镍硫化物矿床特征对比，认为金川铜镍硫化物矿床深熔—就地成矿作用过程为从深部到侵位的持续熔离。岩浆上侵过程中由于高熔点富镁橄榄石及铬铁矿陆续在岩浆房侧边析出固结，使得岩浆房逐渐变小，硫化物不断富集，最终使得小岩体容大矿。     

Adsorption Kinetic and Equilibrium Studies on Removal of Lead(II) onto Glutamic Acid/Sepiolite

In this study, a modified method was used to increase the adsorption of lead ions from aqueous solutions by using modified clay mineral on the laboratory scale. Adsorption experiments have been carried out on the use of both thermal activated sepiolite (TAS) and their glutamate/sepiolite modification (GS) as adsorbents. The experimental data was analyzed using adsorption kinetic models (pseudo first‐ and second‐order equations). The pseudo second‐order kinetic model fitted well to the kinetic data (R² ≥ 0.99). Then, the Freundlich and Langmuir models were applied to describe the uptake of Pb(II) on GS and the Langmuir isotherm model agrees well with the equilibrium experimental data (R² ≥ 0.97). The maximum adsorption capacity was observed to be 128.205 mg/g by GS according to the Langmuir equation. Desorption efficiency of the GS was studied by the batch method using EDTA, HCl, and HNO₃ solutions. Desorption of 69.18, 74.55, and 80% of Pb(II) from GS was achieved with 0.1 M EDTA, 0.1 M HCl, and 0.1 M HNO₃ solutions, respectively. FTIR analysis suggests the importance of functional groups such as amino, hydroxyl, and carboxyl during Pb(II) removal. SEM observations demonstrated that an important interaction at the lead‐modified sepiolite interface occurred during the adsorption process. In addition, the thermodynamic constants was calculated that the values of the Gibbs free energy (ΔG*), enthalpy (ΔH*), and entropy (ΔS*) of modification were 86.79 kJ/mol, ?18.91 kJ/mol, and ?354.70 J/mol/K, respectively. The negative value of ΔH* shows exothermic nature of adsorption.     

Reactions and textures in grossular–wollastonite–scapolite calc–silicate granulites from Maligawila, Sri Lanka: evidence for high-temperature isobaric cooling in the meta-sediments of the Highland Complex

Grossular–wollastonite–scapolite calc–silicate granulites from Maligawila in the Buttala klippe, which form part of the overthrusted rocks of the Highland Complex of Sri Lanka, preserve a number of spectacular coronas and replacement textures that could be effectively used to infer their P–T–fluid history. These textures include coronas of garnet, garnet–quartz, and garnet–quartz–calcite at the grain boundaries of wollastonite, scapolite, and calcite as well as calcite–plagioclase and calcite–quartz symplectites or finer grains after scapolite and wollastonite respectively. Other textures include a double rind of coronal scapolite and coronal garnet between matrix garnet and calcite. The reactions that produced these coronas and replacement textures, except those involving clinopyroxene, are modelled in the CaO–Al₂O₃–SiO₂–CO₂ system using the reduced activities. Calculated examples of T–X_CO2 and P–X_CO2 projections indicate that the peak metamorphic temperature of about 900–875 °C at a pressure of 9 kbar and the peak metamorphic fluid composition is constrained to be low in X_CO2 (0.1<X_CO2<0.30). Interpretation of the textural features on the basis of the partial grids revealed that the calc–silicate granulites underwent high-temperature isobaric cooling, from about 900–875 °C to a temperature below 675 °C, following the peak metamorphism. The late-stage cooling was accompanied by an influx of hydrous fluids. The calc–silicate granulites provide evidence for high-temperature isobaric cooling in the meta-sediments of the Highland Complex, earlier considered by some workers to be confined exclusively to the meta-igneous rocks. The coronal scapolite may have formed under open-system metasomatism.     

Boron Isotopic Composition and Concentration of Ten Geological Reference Materials

We present boron isotope and concentration data from magmatic (komatiitic to rhyolitic) and sedimentary geological silicate and artificial glass reference materials that cover a wide spectrum of boron isotope compositions and boron concentrations. Boron isotope compositions were determined by TIMS (Cs₂BO₂⁺ -graphite and BO₂^- method) and boron concentrations by ICP-AES. Boron concentrations ranged from 7 to 159μ g^-1 and agree within 14% with published values. Based on replicate analyses of individually prepared sample aliquots an overall external reproducibility of better than 10% was determined. The obtained δ¹¹B values ranged from -12.6 to +13.6% and were reproducible within 1.1 % (2 RSD; excluding NTIMS) on the basis of individually prepared sample aliquots. The δ¹¹B values of JA-1 (+5.3%), JB-3 (+5.9%) and JR-2 (+2.9%) overlap the published data within analytical uncertainty. For the first time δ¹¹B values for the TB (-12.6%) and the MPI-DING glasses GOR-128-G (+13.6%), GOR-132-G (+7.1 %) and StHs6/80-G (-4.5%) are reported. The δ¹¹B values obtained by the Cs₂BO₂⁺ -graphite and the BO₂^- method as well as the majority of δ¹¹B values obtained using different sample preparation methods agree within analytical uncertainty. Therefore, we conclude that none of these analytical methods introduce any systematic error on the obtained δ¹¹B values.     

Evaluation of spatial correlation between nutrient exchange rates and benthic biota in a reef-flat ecosystem by GIS-assisted flow-tracking

A Geographic Information System (GIS)-aided flow-tracking technique was adopted to investigate nutrient exchange rates between specific benthic communities and overlying seawater in a fringing reef of Ishigaki Island, subtropical Northwestern Pacific. Net exchange rates of NO₃ ⁻, NO₂ ⁻, NH₄ ⁺, PO₄ ³⁻, Total-N and Total-P were estimated from concentration changes along the drogue trajectories, each of which was tracked by the Global Positioning System and plotted on a benthic map to determine the types of benthic habitat over which the drogue had passed. The observed nutrient exchange rates were compared between 5 typical benthic zones (branched-coral (B) and Heliopora communities (H), seaweed-reefrock zone (W), bare sand area (S), and seagrass meadow (G)). The dependence of nutrient exchange rates on nutrient concentrations, physical conditions and benthic characteristics was analyzed by multiple regression analysis with the aid of GIS. The spatial correlation between nutrient exchange rates and benthic characteristics was confirmed, especially for NO₃ ⁻ and PO₄ ³⁻, which were usually absorbed in hydrographically upstream zones B and W and regenerated in downstream zones H and G. NO₃ ⁻ uptake in zones B and W was concentration-dependent, and the uptake rate coefficient was estimated to be 0.58 and 0.67 m h⁻¹, respectively. Both nutrient uptake in zone W and regeneration in zone H were enhanced in summer. The net regeneration ratio of NO₃ ⁻/PO₄ ³⁻ in zone H in summer ranged 5.2 to 34 (mean, 17.4), which was somewhat higher than previously measured NO₃ ⁻/PO₄ ³⁻ for sediment pore waters around this zone (1.1–8.5). Nutrient exchanges in zone S were relatively small, indicating semi-closed nutrient cycling at the sediment-water interface of this zone. NH₄ ⁺ efflux from sediments was suggested in zone G. The data suggest that the spatial pattern of nutrient dynamics over the reef flat community was constrained by zonation of benthic biota, and that abiotic factors such as nutrient concentrations and flow rates, influenced nutrient exchange rates only in absorption-dominated communities such as zones B and W.     

甲基硅酸盐抑制粘土水化性能及机理

泥页岩水化分散是引起钻孔孔壁失稳,导致缩径、掉块、坍塌等孔内事故的主要原因,泥页岩抑制剂一直是复杂地层钻进技术研究的热点。通过对甲基硅酸钾、甲基硅酸钠、氯化钾、硅酸钠、硅酸钾5种抑制剂对粘土沉降稳定性、水化膨胀及造浆效果等性能测试,结果表明甲基硅酸盐具有良好抑制性;通过红外光谱、X射线衍射、水接触角和光学显微镜对甲基硅酸钾的抑制性作用机理进行了探讨。明确了钾离子的抑制性与表面疏水膜结构协同是甲基硅酸钾抑制粘土水化和防塌作用的原因。