矿物粉尘溶解行为的电镜研究及其生物化学意义

本文对用Ｇａｎｂｌｅ溶液、有机酸及无机强酸溶解后的矿物粉尘残余物进行了扫描电子显微镜分析。结果表明,矿物纤维粉尘纤维变短、长径比减小、柔性减弱、端部变圆,部分溶解成串珠状;粗大颗粒松散塌陷,表面粗糙度增加;片状粉为碎变细;硅酸盐矿物粉尘具有向以ＳｉＯ２为主要成分的纳米级近球形颗粒转化的趋势。故提出在纳米级别上研究粉尘致病机理是非常有价值的。     

超浅海风暴潮的数值模拟(一)——零阶模型对渤海风潮的初步应用

由我国北方的寒潮或冷空气所引起的渤海风潮,按文献的分析,该属于“超浅海风暴潮”类型.以渤海风潮为例,按超浅海风暴潮理论进行数值计算,不仅对该理论是一有力的检验,且对探讨渤海风潮的机制和预报也是一个有益的参考. 将冷锋所造成的大风风场重现在计算网格上,在现场海面风资料极度贫乏的情况下,显然是一较难的课题.本文仅就发生渤海风潮时,渤海上空风场的几个主要力学特征,设计了几个理论模式风应力场,对渤海风潮进行了数值计算,以期获得全过程概貌及主要特征.计算结果达到了这一预期目的.     

Development and verification of the comprehensive model for physical properties of hydrate sediment

Natural gas hydrate is widely distributed all over the world and may be a potential resource in the near future, whereas hydrate dissociation during the development affects wellbore stability and drilling safety. However, the present modeling of hydrate reservoir parameters ignored the influence of effective stress and only considered the hydrate saturation. In this paper, a series of stress sensitivity experiments for the unconsolidated sandstone were carried out, and the influence of mean effective stress on physical parameters was obtained; a comprehensive model for the physical parameters of hydrate reservoir was developed subsequently. With the help of ABAQUS finite element software, the established comprehensive model was verified by the use of the wellbore stability numerical model of hydrate reservoir. The verification results show that ignoring the effect of mean effective stress on the parameters of hydrate formation aggravates the invasion of drilling fluid into the hydrate formation. Besides, ignoring the stress sensitivity of reservoir physical parameters will underestimate the wellbore instability during hydrate drilling, which will be a threat to the safety of gas hydrate drilling. At the end of the drilling operation, the maximum plastic strain of the model for considering and not considering stress sensitivity was 0.0145 and 0.0138, respectively. Therefore, the established comprehensive model will provide a theoretical support for accurately predicting the engineering geological disasters in hydrate development process.     

Atmospheric Correction Over Coastal Turbid Waters of Bay of Bengal Using OCEANSAT-I Ocean Colour Monitor (OCM) Data

Space-borne ocean-colour remote sensor-detected radiance is heavily contaminated by solar radiation backscattered by the atmospheric air molecules and aerosols. Hence, the first step in ocean-colour data processing is the removal of this atmospheric contribution from the sensor-detected radiance to enable detection of optically active oceanic constituents e.g. chlorophyll-a, suspended sediment etc. In standard atmospheric correction procedure for OCEANSAT-1 Ocean Colour Monitor (OCM) data, NIR bands centered at 765 and 865 nm wavelengths were used for aerosol characterization. Due to high absorption by water molecules, ocean surface in these two wavelengths acts as dark background, therefore, sensor detected radiance can be assumed to have major contribution from atmospheric scattering. For coastal turbid waters this assumption of dark surface fails due to the presence of highly scattering sediments which causes sufficient water-leaving radiance in NIR bands and lead to over-estimation of aerosol radiance resulting in negative water leaving radiance for λ < 700 nm. In the present study, for the turbid coastal waters in the northern Bay of Bengal, the concept of spatial homogeneity of aerosol and water leaving reflectance has been applied to perform atmospheric correction of OCAEANSAT-1 OCM data. The results of the turbid water atmospheric correction have also been validated using in-situ measured water-leaving radiance. Comparison of satellite derived water-leaving radiance for five coastal stations with in-situ measured radiance spectra, indicates an improvement over the standard atmospheric correction algorithm giving physically realistic and positive values. Root Mean Square Error (RMSE) between the in-situ measured and satellite derived water leaving radiance for wavelengths 412 nm, 443 nm, 490 nm, 512 nm and 555 nm was found to be 1.11, 0.718, 0.575, 0.611 and 0.651%, respectively, using standard atmospheric correction procedure. By the use of spatial homogeneity concept, this error was reduced to 0.125, 0.173, 0.176, 0.225, and 0.290 and the correlation coefficient arrived at 0.945, which is an improvement over the standard atmospheric correction procedure.     

A review of the NEMURO and NEMURO.FISH models and their application to marine ecosystem investigations

The evolution of the North Pacific Ecosystem Model for Understanding Regional Oceanography (NEMURO) family of models to study marine ecosystems is reviewed. Applications throughout the North Pacific have shown the models to be robust and to be able to reproduce 1D, 2D and 3D components of nutrient, carbon cycle and biogeochemical cycles as well as aspects of the lower trophic levels ecosystem (phyto- and zooplankton). NEMURO For Including Saury and Herring, an extension that includes higher trophic levels, can be run uncoupled or coupled to NEMURO. In the uncoupled mode, the growth and weight of an individual fish is computed using plankton densities simulated by NEMURO but with no feedback between fish consumption and plankton mortality. In the coupled mode, the feeding, growth and weight of a representative fish are computed, and prey removals due to feeding by fish appear as mortality terms on the prey. The NEMURO family of models continues to evolve, including effects of the microbial loop and iron limitation at lower trophic levels, and full life cycle, multi-species and multi-generational simulations at higher trophic levels. We outline perspectives for future end-to-end modeling efforts that can be used to study marine ecosystems in response to global environmental change.     

乐清湾水交换特征研究

采用EFDC模式模拟研究了乐清湾水交换的三维过程和时空变化特征,并通过计算水示踪剂质量浓度分析水体置换过程。结果表明,乐清湾水交换主要是由鹿西岛两侧流入的外海水体与湾内水体的交换,以及乐清湾口门西侧附近的湾内水体与瓯江北口径流冲淡水之间的交换。从口门到湾顶,水交换能力差别较大。以最窄的连屿至打水山断面为界,以南水体1个月基本可以完全交换,而以北水体2个月后仍然无法交换至湾口水平。连屿至打水山断面以北地形复杂,岛屿较多,污染物主要通过岛屿间的潮汐汊道输运,断面的瓶颈效应也使得断面以北的水体交换能力稍弱。在口门附近90%以上的水体被外海置换所需时间不到5 d,而此时湾顶水质未有太大改变;15 d左右,80%湾内水体被外海水置换;90%湾内水体被置换仅需40 d;70 d时的水体置换率达97%。     

海洋沉积样品~(14)C测年差异来源及其结果解释

~(14)C测年已为海洋研究工作广泛应用,但由于时有不合理取样或在运用数据时没有充分考虑各种海洋环境和动力因素,因而产生无法使用数据作合理解释的现象。本文试从海洋样品本身和海洋各种营力作用分析各种数据差异的来源,认为海洋环境特别是海岸带环境的复杂性是造成海洋样品~(14)C测年数据差异的主要原因,它可能影响样品的代表性或使数据解释时得出错误结论.并指出在运用年代结果时一定要充分考虑地质地理和各种营力作用因素。     

Assessing desertification by using soil indices

Desertification generally refers to land degradation in arid, semiarid, and dry semi-humid climatic zones. It involves five principal processes: vegetation degradation, water erosion, wind erosion, salinization and waterlogging, and soil crusting and compaction. The aim of this study is assessing desertification using soil criteria. For this purpose, nine indices including sodium absorption ratio (SAR), soil gypsum percentage, soil texture, the content of HCO₃ ^?, the percentage of the organic matter, electrical conductivity (EC), pH, the content of the soil sodium, and chloride were used. The soil samples were taken in the north of Zayandeh-Rood River in Isfahan province of Iran, using soil data randomly sampled in a depth of 0–20 cm. After assessing the normality of the samples using Kolmogorov-Smirnov test, indices were imported into GIS environment and interpolated with IDW and normal and discrete kriging methods for delineating soil characteristics maps based on MEDALUS model. In this model, the data were firstly changed from 100 to 200. Thus 100 and 200 are estimated as the best and worst quality, respectively. Then the final map of soil criteria has been created by geometric mean of its indicators. The results showed that the maximum area is related to the medium class of desertification and is equal to 44,746 ha. The areas of severe and very severe classes of desertification are equal to 30,949 and 351 ha, respectively. The results also revealed that the indices of the organic matter and soil gypsum percentage are the most influential indices which affect desertification phenomenon.     

藏南沙拉岗锑矿流体包裹体红外显微测温研究

沙拉岗锑矿是藏南金锑成矿带内最具有代表性的锑矿床。为了更直接地了解该矿床的流体物理化学特征,本文利用红外显微镜对辉锑矿及紧密共生石英中的流体包裹体进行了显微测温研究。红外显微测温分析结果表明,辉锑矿中包裹体均一温度在134.9～221.9℃,峰值在160～190℃之间,盐度在1.7%～7.3%NaCleqv,峰值在5.0%～6.0%NaCleqv之间,密度在0.879～0.958g/cm3之间,平均值为0.934g/cm3;共生石英中包裹体均一温度在142.5～205.6℃,峰值在160～190℃之间,盐度在2.3%～7.0%NaCleqv,峰值在4.0%～6.0%NaCleqv之间,密度在0.910～0.947g/cm3之间,平均值为0.929g/cm3。通过对比研究认为沙拉岗辉锑矿及共生石英形成于同一物理化学条件,捕获同一成矿流体。结合石英中单个流体包裹体激光拉曼成分分析认为成矿流体为含微量CO2、N2、CH4气体的低温、低盐度和低密度的NaCl-H2O热液体系。成矿流体的沸腾作用是辉锑矿大量沉淀主要原因。     

Discussion on the dynamic mechanism of Great North China area based on the observed stress data

Introduction The Great North China, located at longitude 106E to 124E and latitude 31N to 42N, in-cludes three secondary active tectonic blocks, Ordos, Yanshan and North China plain (Figure 1). The geological tectonics of these three secondary blocks is much different from each other. As a stable block with high rigidity, the Ordos block is mostly surrounded by down-faulted basins with an inactive interior since Cenozoic, although the fault zones along its boundary are strongly active wi…