水面蒸发与散热系数公式研究(二)

根据自1976年以来全国水面蒸发与散热研究协作组在我国各典型地区的原体与室内实验资料和大量水文站历史资料,通过理论分析和统计检验,确定了影响水面蒸发的诸因子及其非线性相互作用,引入了新的无量纲参数和公式结构,用实测资料统计确定了公式中的常系数,得到了用开敞湖面一般水文气象资料计算逐日蒸发和散热系数的公式。经全国务典型气候带内务季节湖泊(水库)和受热污染水体上原体观测和室内专题实验共1860组日平均检验,公式的精度高于现有其他公式。全文分两部分,本文刊出第二部分,内容包括:公式的检验;水文气象要素对α的影响;水面散热系数的计算和结语。     

Core formation and chemical equilibrium in the Earth—I. Physical considerations

Current models of planetary formation suggest a hierarchy in the size of planetesimals from which planets were formed, causing formation of a hot magma ocean through which metal-silicate separation (core formation) may have occurred. We analyze chemical equilibrium during metal-silicate separation and show that the size of iron as well as the thermodynamic conditions of equilibrium plays a key role in determining the chemistry of the mantle (silicates) and core (iron) after core formation. A fluid dynamical analysis shows that the hydrodynamically stable size of iron droplets is less than 10⁻² m for which both chemical and thermal equilibrium should have been established during the separation from the surrounding silicate magma. However, iron may have been separated from silicates as larger bodies when accumulation of iron on rheological boundaries and resultant large scale gravitational instability occurred or when the core of colliding planetesimals directly plunged into the pre-existing core. In these cases, iron to form the core will be chemically in dis-equilibrium with surrounding silicates during separation. The relative role of equilibrium and dis-equilibrium separation has been examined taking into account of the effects of rheological structure of a growing earth that contains a completely molten near surface layer followed by a partially molten deep magma ocean and finally a solid innermost proto-nucleus. We show that the separation of iron through a completely molten magma ocean likely occurred with iron droplets assuming a hydrodynamically stable size ( 10⁻² m) at chemical equilibrium, but the sinking iron droplets are likely to have been accumulated on top of the partially molten layer to form a layer (or a lake) of molten iron which sank to deeper portions as a larger droplet. The degree of chemical equilibrium during this process is determined by the size of droplets which is in turn controlled by the size and frequency of accreting planetesimals and the rheological properties of silicate matrix. For a plausible range of parameters, most of the iron that formed the core is likely to have been separated as large droplets or bodies and chemical equilibrium with silicate occurred only at relatively low temperatures and pressures in a shallow magma ocean or in their parental bodies. However, a small portion of iron that separated as small droplets was in chemical equilibrium with silicate at high temperatures and pressures in a deep magma ocean during the later stage of core formation. Therefore the chemistry of the core is mostly controlled by the chemical equilibrium with silicates at relatively low temperatures and pressures, whereas the chemistry of the mantle controlled by the interaction with iron during core formation is likely to have been determined mostly by the chemical equilibrium with a small amount of iron at high temperatures and pressures.     

Methodological approaches to pollution assessment in water bodies within the operation zone of mining plants

A series of methods for assessing water body pollution by chemical characteristics are considered as applied to water bodies in the operation zone of mining plants. In some methods, the estimate of water body pollution may reflect regional features of waters, rather than their pollution. Evaluating the environmentally allowable concentrations of elements and their biogeochemical tolerance has shown those values to increase with increasing water body pollution, a fact that contradicts the essence of those characteristics. The most simple and universal is a procedure for evaluating water pollution index with the use of regional MACs, taking into account the geochemical background concentrations of the elements and their toxicity using as a criterion the value of MAC for water bodies used for fishery.     

DO-Process Models for Shallow Systems. Part 1: Ponds and Lakes

Model statements are presented for describing the oxygen concentration in dependence on various system quantities and five different shallow water bodies. A nonlinear model in the form of a polynomial and with parameter estimation by means of recursive regression proves suitable. It is a blackbox model in which the water temperature, the biomass of phytoplankton and zooplankton and the solar irradiation are the most important input quantities. The model applications to the five water bodies reach measures of determinateness of 0.6 … 0.74 and mean square deviations between the measured and calculated oxygen concentrations of 3 … 4 mg/l O₂. Simulations of the model output by changed input data are discussed.     

水面蒸发与散热系数公式研究(一)

根据自1976年以来全国水面蒸发与散热研究协作组在我国各典型地区的原体与室内实验资料和大量水文站历史资料,通过理论分析和统计检验,确定丁影响水面蒸发的诸因子及其非线性相互作用,引入了新的无量纲参数(w_e、Pv、Pe)和公式结构,用实测资料统计确定厂公式中的常系数,得到了用开敞湖面一般水文气象资料计算逐日蒸发和散热系数的公式。经全国各典型气候带内各季节湖泊(水库)和受热污染水体上原体观测和室内专题实验共1860组口平均资料检验,公式的精度高于现有其他公式。全文分两部分,这是第一部分,内容包括:影响水面蒸发的土要无量纲参数;感热输送和大气饱和度对蒸发影响的修正;水面蒸发计算公式的结构及其经验系数。     

哈纳斯湖的水下地貌与表层沉积物的若干特征

测量表明,哈纳斯湖最大水深达188.5m,平均水深达120.1m,优质淡水容量达53.78×10~8m~3,均在我国湖泊中居突出地位。横断面为罕见的典型箱形,断陷作用仍在强烈进行之中。湖底表层沉积物粒度参数之分布主要受纵向搬运作用控制,局部受横向搬运作用影响。沉积物的矿物学特征与元素分布特征明显受沉积环境控制。沉积物中营养元素含量总体偏低。~(210)Pb法测得平均沉积速率为0.52mm/a,难以补偿断陷作用,湖盆将继续加深。     

Extended Sediment Quality Rating for Trace Elements in Urban Waters – Case Study Klinke,Germany

The European Water Framework Directive (WFD) commits European Union member states to achieving good ecological status in all water bodies by 2015. For sediments the definition of good chemical status is based on numerical sediment quality guidelines. The aqua regia fraction is thus used for the evaluation of heavy metal concentrations in sediments. The chemical constituents in sediments responsible for mobility and toxicity are not considered generally. This article presents the combining of the sequential BCR procedure, for determining the chemical species of relevant elements, with the geoaccumulation index principle a numerical classification method for sediment quality guidelines. Using the BCR method it can be demonstrated that changes in element speciation can lead to more highly mobile species of trace elements which may affect the hazardous potential of sediments despite the “good chemical status” classification for aqua regia digestions. The Klinke stream is an urban surface water body located in Magdeburg, the state capital of Saxony‐Anhalt, Germany. Using this stream as an example it is shown that this additional information helps to describe the dynamics and discharge of the trace elements Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Rb, Sr, Mo, Pd, Cd, Sb, Ba, Pb, Bi, and U into the Elbe River from urban water bodies.     

The age of ferroan anorthosite 60025: oldest crust on a young Moon?

SmNd isotopic data for mineral separates from the ferroan anorthosite 60025 define a precise isochron of 4.44 ± 0.02Ga age. This age is roughly 110 m.y. younger than the formation of the first large solid objects in the solar nebula, as recorded by the radiometric ages of the differentiated meteorites. In the magma ocean model for early lunar differentiation, ferroan anorthosites are the first crustal rocks to form on the Moon. If the Moon is as old as the oldest meteorites, the relatively young age determined for 60025 implies either that the magma ocean did not form synchronously with lunar formation, or that the magma ocean required over 100 m.y. before reaching the stage of ferroan anorthosite crystallization. Alternatively, we propose that the accumulated body of radiogenic isotope data for lunar rocks permit the Moon to be as young as 4.44–4.51 Ga. If so, isotopic evidence for chemical differentiation on the Earth at about this same time suggests that the formation of the Moon is reflected in the chemical evolution of the Earth. This, in turn, is consistent with the idea that the materials that now make up the Moon were derived from the Earth, perhaps ejected by collision between the Earth and another very large planetesimal during the final stages of accumulation of the terrestrial planets. Terrestrial origin models for the Moon lessen the requirement that the Earth and Moon each have near chondritic relative abundances of the refractory elements and could require that certain chemical and isotopic characteristics of both bodies be considered in the framework of the chemical mass-balance of the combined Earth-Moon system.     

Native iron in the Earth and space

Thermomagnetic and microprobe studies of native iron in the terrestrial upper-mantle hyperbasites (xenoliths in basalts), Siberian traps, and oceanic basalts are carried out. The results are compared to the previous data on native iron in sediments and meteorites. It is established that in terms of the composition and grain size and shape, the particles of native iron in the terrestrial rocks are close to each other and to the extraterrestrial iron particles from sediments and meteorites. This suggests that the sources of the origin of these particles were similar; i.e., the formation conditions in the Earth were close to the conditions in the meteorites’ parent bodies. This similarity is likely to be due to the homogeneity of the gas and dust cloud at the early stage of the solar system. The predominance of pure native iron in the sediments can probably be accounted for by the fact that interstellar dust is mostly contributed by the upper-mantle material of the planets, whereas the lower-mantle and core material falls on the Earth mainly in the form of meteorites. A model describing the structure of the planets in the solar system from the standpoint of the distribution of native iron and FeNi alloys is proposed.     

On the chemical composition of the Moon,Jupiter, meteorites and Am stars

If surface anomalies in the composition of the metallic-line A stars (Am stars) are due to a precipitation of planet-like bodies (planetoids) on them, then one should expect a correlation to exist between the overabundance of heavier-than-iron elements on these stars and their “standard” abundances in the solar system (since chondrites provide the “standard” level for these elements). However, an anticorrelation was revealed.Nevertheless, this fact supports the original suggestion on the origin of the metallicism of A stars, and can easily be explained within the author's hypothesis on the formation of the Sun from matter escaping from the proto-Jupiter. During the terminal stages of mass transfer, the matter was strongly depleted in refractories (forming the rocky core of Jupiter). Therefore the composition of the meteorites formed should not coincide with the primary composition of the matter. Thus the Sun's outer layers may also have a distorted composition. The author concludes that it is desirable to revise the “standard” abundances of elements heavier than iron.From a comparison of the surface composition of Am stars with the composition of lunar anorthosites and that of rocks in the upper zones of the Skaergaard intrusion (Greenland), the Am phenomenon may be seen to result from a precipitation of large geochemically differentiated planetoids onto a star. Such planetoids (including the Moon) condense in the cooled envelope of the primary component of a close binary stellar system.     

江西德安县地方性氟中毒区生态地球化学研究

江西德安吴山地区地方性氟中毒区域存在高氟的地球化学异常。富氟的岩（矿）石为其原生源,受表生地质作用和人为活动的影响,在土壤、水和生物体中形成了富氟的生态地球化学环境系统。研究发现,该地区氟进入人体主要通过5个途径,其中食物是进人人体最主要途径,食物中的氟元素超标情况严重,其次是通过饮用水进入人体,并根据这些规律提出德安地方性氟中毒病几点防治建议。     

青藏高原陆相介形类的分布特征及其对生态环境的响应

统计分析了青藏高原不同区域水体环境表层沉积物陆相介形类的属种分布特征,探讨了介形类在不同水环境下（盐度、pH值及水深）对生态环境的响应.结果显示,青藏高原现生介形类共计21属67种,其中Candona candida、Ilyocypris bradyi、Eucypris inflata、Limnocythere dubiosa、Limnocythere inopinata、Paracypricerus angulata、Leucocytherella sinensis和Leucocythere mirabilis为青藏高原地区的常见种.湖泊、河流、洼地和湿地4类水体环境中,湖泊中介形类最为丰富,达19属62种;青藏高原东北部（祁连山和柴达木盆地）、北部（昆仑山）、西部和南部不同区域的介形类常见种存在较大差异,可能是区域海拔、pH值和盐度综合作用的结果.淡水和微咸水环境介形类属种数量较咸水及盐湖中丰富,分别有17属41种和13属42种,Limnocythere dubiosa （0.52~90.6 g/L）和Leucocythere mirabilis（0.51~174.63 g/L）在淡水、咸水及盐湖中均有出现,适应盐度范围较广;pH值在8.0~10.0范围内介形类属种多样性最丰富,表明大部分介形类具有嗜碱性的特征;青藏高原陆相介形类属种多样性随水深的增加而降低,浅湖（0~15 m）中介形类属种最为丰富,达到17属52种,其中Candona candida（0.2~80 m）和Leucocythere dorsotuberosa（0.3~110 m）从滨湖至深湖区均有分布,二者均具有较大的水深适应范围.     

月表温度对于月幔对流影响的数值模拟研究

行星内部对流计算中, 一般都将其表面温度作为常温处理.但在月球、水星等无大气的天体表面, 温度与纬度明显相关, 月球两极和赤道的平均温度相差可以达到100 K以上.纬度相关的温度边界条件, 是否会影响天体早期对流特征与内部热状态, 过去没有得到重视和研究.本文使用有限元方法进行了二维球壳对流模型的热演化模拟, 以评估无大气行星上, 与纬度高度相关的表面温度对其内部对流和演化的影响.模拟计算结果表明, 表面温度会对月球对流形态产生较大影响, 两极因为相对更冷而易于形成下降流, 上升流更倾向于从赤道位置开始, 在早期演化中表现得尤为明显.受边界条件影响, 月球两极与赤道的岩石圈厚度差异可以达到400 km以上.今后在研究太阳系内月球、水星一类没有大气的天体演化、特别是早期演化时, 对于表面温度纬度相关分布的影响应该予以考虑.

     

Fractionation and mantle heterogeneity in basalts from the Peru-Chile Trench

Five separate exposures of oceanic basalts were dredged in the vicinity of the Peru-Chile Trench between 9° and 27°S latitude. Each dredge is dominated by abundant pillow basalts. Approximately ten of the most unaltered, glassy and fine-grained samples were selected for detailed chemical and petrographic analyses from each dredge area. All basalts recovered in the Peru-Chile Trench are olivine and quartz-normative tholeiites that are believed to have formed at the now extinct Galapagos Rise 30–50 m.y. ago. Detailed chemical analyses of the basalts, including major and selected trace and rare earth elements, indicate that considerable compositional variability exists both within each of the dredged areas as well as between areas. Most of the inherent chemical variability observed within particular basement sections appears consistent with the concept of temporal evolution of magma bodies at a former spreading center by shallow-level fractional crystallization involving primarily plagioclase and olivine. In contrast, important chemical differences between the dredged areas suggest compositional heterogeneities in the mantle source regions. Our results indicate that although shallow-level fractionation has brought about large changes in composition of basalts in each area, compositional trends are distinct and appear to reflect original mantle-derived compositional differences.     

Sediments,porewaters and diagenesis in an urban water body,Salford, UK: impacts of remediation

Contaminated sediments deposited within urban water bodies commonly exert a significant negative effect on overlying water quality. However, our understanding of the processes operating within such anthropogenic sediments is currently poor. This paper describes the nature of the sediment and early diagenetic reactions in a highly polluted major urban water body (the Salford Quays of the Manchester Ship Canal) that has undergone remediation focused on the water column. The style of sedimentation within Salford Quays has been significantly changed as a result of remediation of the water column. Pre‐remediation sediments are composed of a range of natural detrital grains, predominantly quartz and clay, and anthropogenic detrital material dominated by industrial furnace‐derived metal‐rich slag grains. Post‐remediation sediments are composed of predominantly autochthonous material, including siliceous algal remains and clays. At the top of the pre‐remediation sediments and immediately beneath the post‐remediation sediments is a layer significantly enriched in furnace‐derived slag grains, input into the basin as a result of site clearance prior to water‐column remediation. These grains contain a high level of metals, resulting in a significantly enhanced metal concentration in the sediments at this depth. Porewater analysis reveals the importance of both bacterial organic matter oxidation reactions and the dissolution of industrial grains upon the mobility of nutrient and chemical species within Salford Quays. Minor release of iron and manganese at shallow depths is likely to be taking place as a result of bacterial Fe(III) and Mn(IV) reduction. Petrographic analysis reveals that the abundant authigenic mineral within the sediment is manganese‐rich vivianite, and thus Fe(II) and Mn(II) released by bacterial reactions may be being taken up through the precipitation of this mineral. Significant porewater peaks in iron, manganese and silicon deeper in the sediment column are most probably the result of dissolution of furnace‐derived grains in the sediments. These species have subsequently diffused into porewater above and below the metal‐enriched layer. This study illustrates that the remediation of water quality in anthropogenic water bodies can significantly impact upon the physical and chemical nature of sedimentation. Additionally, it also highlights how diagenetic processes in sediments derived from anthropogenic grains can be markedly different from those in sediments derived from natural detrital material. Copyright © 2003 John Wiley & Sons, Ltd.     

Effects of the Sun on the Earth's environment

Solar disturbances are observed to have significant effects in near-Earth space. Over the past half-century of observation, a relatively clear picture has developed of how and why the typical solar wind — as well as the most extreme solar events — drive geospace responses. It is clear that magnetospheric substorms, geomagnetic storms (both recurrent and aperiodic events), and even certain atmospheric chemical changes have their origins in the solar–terrestrial coupling arena. High-speed solar wind streams and fast coronal mass ejections (CMEs) can often have strong interplanetary shock waves and southward magnetic fields which can initiate strong storm responses. We demonstrate in this review that available modern space-observing platforms and ground facilities allow us to trace drivers from the Sun to the Earth's atmosphere. This allows us to assess quantitatively the energy transport that occurs throughout the Sun–Earth system during both typical and extreme conditions. Hence, we are continuously improving our understanding of “space weather” and its effects on human society.     

Petrology of the volcanic rocks of saba,West Indies

Saba is composed of basic and intermediate members of the calc alkaline series with a broad resemblance to volcanic rocks on other islands of the northern Lesser Antilles. The most abundant rock-type is hornblende andesite with relatively high potassium and associated elements. Notable petrographic features are the persistence of magnesian olivine into relatively siliceous whole-rock composition and the prevalence of hornblende even in the more basic rocks. Quartz xenocrysts also occur in the basalts Clinopyroxene phenocrysts are of an gite composition but groundmass grains are sometimes in the range subcalcic augite to magnesian pigeonite. Disequilibrium features in the petrography, together with anomalies in the chemical trends may be due to incorporation of xenocrysts or perhaps in extreme instances to the hybridisation of contrasting magmas.     

Toxicity and Accumulation of Al in the Acid Water of Small Lakes and Watercourses in Finnish Lapland

On the basis of a study of the hydrochemical regime and the status of benthic acidophobic species in the acidified watercourses and small lakes of Finnish Lapland, humic compounds are demonstrated to be the principal factors controlling both pH and the proportions of different forms of Al in water. It is found that the concentration of labile aluminum, i.e., that form of aluminum which is most toxic for aquatic organisms, increases only in acid water (pH 4.8–6.5) with a low and extremely low humic content of water (with a color of 5–60 mg Pt/l). Humic and other organic substances that fix Al in an inert or another stable form are demonstrated to be able to decrease the toxic properties of aluminum for acidophobic species and the capacity of aluminum to be accumulated in the bodies of aquatic organisms. Aluminum is shown to have no tendency to an increased rate of accumulation in the bodies of aquatic organisms that form the highest trophic level of secondary predators.     

西藏地区现代沉积物中介形类环境指示意义初探

于2008和2012年先后2次从西藏阿里和那曲地区61个不同水体,包括不同盐度的湖泊、湿地、浅水坑和河流等,共采集了78个水体表层沉积物样品,用以研究该地区现生介形类的生态分布及其环境指示意义.经鉴定,阿里和那曲地区现生介形类共计11属38种.除Ilyocypris neoaspera等5个种外,本次调查的介形类各属种均在湖泊中出现,尤以Limnocythere dubiosa的总壳瓣数最为丰富.Ilyocypris属中除Ilyocypris subdunshanensis和Ilyocypris xizangensis外,其余各种均喜浅水坑的小型浅水环境.Leucocythere dilitata、Limnocythere dubiosa、Limnocytherellina kunlunensis和Eucypris rischtanica为该地区的广盐种.其中Limnocythere dubiosa和Leucocythere dilitata适应盐度范围最广,在不同盐度的各类水体中均有出现.本次研究中的介形类均喜碱性水体,在p H值为8~9的水体中介形类各属种的丰度值达到最大.     

The Formation of Chemical and Isotopic Composition of Surface Water of Open Water Bodies in the Bodrak River Basin (North-Western Slope of the Crimean Mountains)

Water Resources - The major factors governing the formation of the chemical and isotopic compositions of surface water in open water bodies (ponds) in the Bodrak River basin have been studied by...