博茨瓦纳奥拉帕金刚石矿床成矿地质特征

博茨瓦纳是世界上金刚石资源最为丰富的国家之一。奥拉帕金刚石矿床是该国最大的金刚石矿,矿床的金伯利岩为Ⅰ型,其中的包体可以分为2种:橄榄岩型和榴辉岩型;金刚石可以分为3类:橄榄岩型、榴辉岩型及两者的过渡类型-二辉岩型。其中,橄榄岩型和部分榴辉岩型金刚石来自于地幔结晶堆晶体,而榴辉岩型则与板块俯冲的构造-热事件有关。金伯利岩的形成时代主要为白垩纪,而金刚石则主要形成于元古宙和太古宙,金伯利岩和金刚石为不同时期的产物,金刚石为金伯利岩侵位期间捕获的上地幔物理破碎产物。其中年龄为900~1000Ma的金刚石为板块构造-热事件的产物,并对早期金刚石进行了改造破坏。     

A Mathematical Calculation Model Using Biomarkers to Quantitatively Determine the Relative Source Proportion of Mixed Oils

It is difficult to identify the source（s） of mixed oils from multiple source rocks, and in particular the relative contribution of each source rock. Artificial mixing experiments using typical crude oils and ratios of different biomarkers show that the relative contribution changes are non-linear when two oils with different concentrations of biomarkers mix with each other. This may result in an incorrect conclusion if ratios of biomarkers and a simple binary linear equation are used to calculate the contribution proportion of each end-member to the mixed oil. The changes of biomarker ratios with the mixing proportion of end-member oils in the trinal mixing model are more complex than in the binary mixing model. When four or more oils mix, the contribution proportion of each end-member oil to the mixed oil cannot be calculated using biomarker ratios and a simple formula. Artificial mixing experiments on typical oils reveal that the absolute concentrations of biomarkers in the mixed oil cause a linear change with mixing proportion of each end-member. Mathematical inferences verify such linear changes. Some of the mathematical calculation methods using the absolute concentrations or ratios of biomarkers to quantitatively determine the proportion of each end-member in the mixed oils are deduced from the results of artificial experiments and by theoretical inference. Ratio of two biomarker compounds changes as a hyperbola with the mixing proportion in the binary mixing model, as a hyperboloid in the trinal mixing model, and as a hypersurface when mixing more than three end- members. The mixing proportion of each end-member can be quantitatively determined with these mathematical models, using the absolute concentrations and the ratios of biomarkers. The mathematical calculation model is more economical, convenient, accurate and reliable than conventional artificial mixing methods.     

A survey of unbalanced flow diagnostics and their application

1.IntroductionImbalanceisdefinedintermsoftowhatextenttheflowdepartsfromabalancedstate.Despitetheapparentcomplexityofatmosphericmotions,thepressure(massfield)andvelocity(momentum)distributioncanberelatedbyrathersimpleapproximateforcebalances(sothatparcelaccelerationscanbeignored).Davisetal.(1996)pointedoutthattheunderlyingassumptionofbalanceddingnosticsisthatthenowevolvesinawayconsistentwiththerestrictionsimplicitwithinthediagnosticframework.ThesimplesttwobalancerelationsaregeostrOPhl'cbalance…     

A preliminary study on fingerprinting approach in marine sediment dynamics with the rare earth elements

Locating the quantitized natural sediment fingerprints is an important work for marine sediment dynamics study.The total of 146 sediment samples were collected from the Shelf of the East China Sea and five rivers,including Huanghe (Yellow),Changjiang (Yangtze),Qiantang,Ou and Min River.The sediment grain size and the contents of rare earth elements (REEs) were measured with laser particle size analyzer and ICP-MS technology.The results show that absolute REE content (ΣREE) and the concentration ratio of light REEs to heavy REEs (L/HREE) are different in the sediments among those rivers.There are higher REE contents in being less than 2 m and 2–31 μm fractions in the Changjiang Estuary surface sediments.The REE contents of bulk sediment are dominated by the corresponding values of those leading size-fractions.REE of sediment is higher close to the estuaries and declines seaward on the inner shelf of the East China Sea (ECS).The L/HREE ratio has a tendency of increase southward from 28 ? N.Hydrodynamic conditions plays a predominate role on spacial distributions of the surficial sediment’s REE parameters.In some situations,the currents tend to remove the coarser light grains from initial populations,as well as the deposit of the finer heavy mineral grains.In other situations,the currents will change the ratio of sediment constituents,such as ratio between silts and clays in the sediments.As a result,the various values of REE or L/HREE ratio in different bulk sediments are more affected by the change of size-fractions than source location.Under the long-term stable hydrodynamic environment,i.e.,the East China Sea Shelf,new sediment transport model based on the size and density gradation concept may help to understand the spatial distribution patterns of REE parameters.     

Environmental process and convergence belt of atmospheric NO2 pollution in North China

Both surface environmental monitoring and satellite remote sensing show that North China is one of the regions that are heavily polluted by NO₂. Using the NO₂ monitoring data from 18 major cities in the region, the tropospheric NO₂ column density data from the Ozone Monitoring Instrument (OMI) on the Aura satellite, and the observations from the China Meteorological Administration network, this paper analyzes a regional NO₂ pollution event in February 2007 over North China, examines the convergence of the pollutant, and identies its correlation with the atmospheric background conditions. The results show that daily mean NO₂ concentrations derived from surface observations are consistent with the mean values of the OMI measurements, with their correlation coeficient reaching 0.81. The correlations of NO₂ concentration with general weather patterns and sequential changes of temperature structure from 925 hPa down to the surface indicate that the weather fronts, high pressure and low pressure systems in the atmosphere play a role in changing the temporal and spatial evolutions of NO₂ through removing, accumulating or converging of the pollutant, respectively. It is also found that the eastern Taihang Mountains is most heavily polluted by NO₂ in North China. Based on a model that correlates NO₂ column density with surface wind vector, the relation of the NO₂ concentrations in six major cities in North China to the surrounding wind field is analyzed. The results show that the maximum wind field is associated with the highest frequency of pollution events, and under certain large-scale atmospheric conditions together with the topographic effect, small- and meso-scale wind fields often act to transport and converge pollutants, and become a major factor in forming the heaviest NO₂ pollution event in North China. Analysis of the causes for the severe NO₂ pollution event in this study may shed light on understanding, forecasting, and mitigating occurrences of heavy NO₂ pollution.     

添加固体碳源对垂直流人工湿地污水处理效果的影响

以垂直流人工湿地小试系统为研究对象,探讨了不同位置(表层、上层、中层和下层)添加固体碳源对系统氮、磷及COD_Cr去除效果的影响.结果表明:湿地下层硝态氮去除率低于中层,最适宜碳源添加位置为垂直流人工湿地中、下层.添加碳源系统中,碳源添加位置为表层的系统COD_Cr去除率最高,各系统出水COD_Cr浓度均低于进水,不引起系统出水中COD_Cr浓度的增加.添加碳源显著提高脱氮除磷效果,碳源添加位置为下层的系统TN去除率最高,碳源添加位置为表层的系统氨氧化作用明显,出水铵态氮浓度最高,各系统对亚硝态氮和硝态氮去除率差异不明显,但对硝态氮都表现出良好的去除效果.碳源添加位置为下层的系统硝化作用最完全,TP去除能力也显著优于其他各系统.添加碳源至垂直流人工湿地下层可以达到同步脱氮除磷的效果.     

赞比亚东北部班韦乌卢地块泛非期以来构造演化的裂变径迹约束

本文利用锆石和磷灰石裂变径迹方法探讨了班韦乌卢地块泛非期以来的主要构造演化时间。为研究班韦乌卢地块的构造活动,本文从班韦乌卢地块中部卡帕图地区的沉积盖层姆波罗科索群的姆巴拉组、萨马组和卡布韦卢马组中采集多件新鲜的岩石样品,并获得5件锆石和2件磷灰石样品裂变径迹分析结果。5件锆石裂变径迹年龄介于575±35～380±22 Ma之间,其峰值年龄组为600～572 Ma和420～390 Ma。2件磷灰石裂变径迹年龄介于59±6～27±4 Ma之间,其峰值年龄组为99～80 Ma和19～11 Ma。它们的峰值年龄组分别对应的主要时代为新元古代的埃迪卡拉纪、早泥盆世、晚白垩世和中新世。对比区域上已有的年龄数据可知,南部非洲地区新元古代的埃迪卡拉纪、早泥盆世和晚白垩世的构造活动是一个区域性的构造事件,仅中新世(19～11 Ma)的构造活动在区域上的表现尚不明确。综合前人成果资料,自泛非构造运动以来,班韦乌卢地块至少经历600～572 Ma、488～441 Ma、420～390 Ma、375～293 Ma、99～80 Ma及19～11 Ma六个构造事件。班韦乌卢地块泛非期以来的构造演化研究程度很低,...     

Assemblage characteristics of clay minerals and its implications to evolution of eolian dust input to the Parece Vela Basin since 1.95 Ma

To understand the provenance and evolution of eolian input in the last 1.95 Ma in the Parece Vela Basin in the eastern Philippine Sea, the clay mineral assemblage of a gravity core PV090510 from the basin was investigated using paleogeomagnetic dating and X-ray diffraction. The assemblage of the core mainly consisted of smectite （-46%） and illite （-40%）, with some chlorite （-10%） and kaolinite （-4%）. Analysis of the provenance of these minerals suggested that smectite was mainly derived from volcanic rocks of the Mariana Arc, while illite, chlorite, and kaolinite were mainly transported as eolian dust by the East Asian monsoon from central Asia. We used the ratio of （illite＋chlorite＋kaolinite）/smectite as a proxy for Asian eolian input to the Parece Vela Basin since 1.95 Ma. This ratio followed glacial and interglacial cycles and was consistent with the intensity of the East Asian monsoon and aridity of central Asia since 1.95 Ma. The changes of the ratio reflected three different stages of the East Asian monsoon and provenance climate.     

Downward transport and modification of tropospheric ozone through moist convection

This study estimated the largely unstudied downward transport and modification of tropospheric ozone associated with tropical moist convection using a coupled meteorology-chemistry model. High-resolution cloud resolving model simulations were conducted for deep moist convection events over West Africa during August 2006 to estimate vertical transport of ozone due to convection. Model simulations realistically reproduced the characteristics of deep convection as revealed by the estimated spatial distribution of temperature, moisture, cloud reflectivity, and vertical profiles of temperature and moisture. Also, results indicated that vertical transport reduced ozone by 50% (50 parts per billion by volume, ppbv) in the upper atmosphere (12–15 km) and enhanced ozone by 39% (10 ppbv) in the lower atmosphere (<2 km). Field observations confirmed model results and indicated that surface ozone levels abruptly increased by 10–30 ppbv in the area impacted by convection due to transport by downdrafts from the upper troposphere. Once in the lower troposphere, the lifetime of ozone decreased due to enhanced dry deposition and chemical sinks. Ozone removal via dry deposition increased by 100% compared to non-convective conditions. The redistribution of tropospheric ozone substantially changed hydroxyl radical formation in the continental tropical boundary layer. Therefore, an important conclusion of this study is that the redistribution of tropospheric ozone, due to deep convection in non-polluted tropical regions, can simultaneously reduce the atmospheric loading of ozone and substantially impact the oxidation capacity of the lower atmosphere via the enhanced formation of hydroxyl radicals.     

机载扫描仪CCT格式器

根据机载扫描仪的特点和遥感用户的要求,精心研制了在脱机状态下运行的CCT格式器。其主要功能:(1)将模拟磁带上的多光谱遥感信息数字化,制成便于计算机处理的通用格式化产品——计算机兼容磁带(CCT);(2)读出CCT上的数据,进行图像的快速显示或硬拷贝;(3)对指定的子区目标,进行快速查找与定位。 本文详细论述CCT格式器硬件和软件设计特点,给出磁带数据格式,介绍一些使用情况。该格式器不仅作为机载扫描仪的主要配套设备之一,而且也适合那些需要处理大量磁带数据的图像处理系统。