英国两古金属矿区中Cd,Cu,Pb和Zn的迁移及其后果

本文报道了对两个古Ｐｂ－Ｚｎ矿中重金属元素迁移的监测，即金属元素通过大气尘降和河流运移向古矿周围的土壤、河流沉积物及其植被中迁移的情况。结果表明，古矿关闭后的８０￣１００年中相当大量的Ｃｄ、Ｐｂ、Ｚｎ和Ｃｕ（只在一个矿区）进行了土壤和水系中。在尾矿堆周围３００ｍ范围内，大气尘降的重金属元素每年有多达３．３ｋｇ的Ｃｄ、７１Ｋｇ的Ｃｕ、３７３ｋｇ的Ｐｂ和１０４ｋｇ的Ｚｎ迁入了土壤和植被中。研究还发现，     

DEVELOPMENT OF A SURFACE PLUME MODEL AND ITS APPLICATION TO SEDIMENT TRANSPORT MODELLING OF DREDGING IN COASTAL WATERS

I INTRODUCTIONSediment dredging operations are effective means of maintaining the natural navigation channel ofshipping for transportation of passengers and cargoes (Goldbeck 1998, Wakeman 1998). Expansions ofexisting ports to facilitate the groWth in marine traffic often necessitate navigation channel dredgingactivities (Foxworthy et. al. 1995, Luger et. al. 1998). Dredging is also heavily used for marine mining ofthe scabed deposits for gold or minerals (Anon 1996, Gamett 1996), and …     

Deep-seated structure and gold content of Russia and China contiguous territories

On the contiguous territories of southeastern Russia and northeastern China,many gold-bearing areas are conjugate in space with the gradient zones of the gravity field.Large gold-ore districts,defining in many respects the metallogenic signature of the region,are located on the joints of differently oriented gradient zones.In the best-studied districts,the Precambrian protrusions,staged distribution of magmatic chambers (by vertical) above the Mohorovicic discontinuity and restriction to the peripheral parts of intrusive massifs have been recognized.Different-type gold deposits in the studied ore-placer districts and nodes are often located on the areas of joint of the granitoid massifs and subvolcanic bodies with depressions.Availability of areals of metasomatic alterations of rocks,placers,and ore occurrences of precious metals on such but poorly studied areas can serve as the basis for the revision and detailed forecasting-prospecting works to develop the mineral-raw material base of the region for precious metals.     

热带气旋中的角动量输送

1.引言相对于热带气旋中心为垂直轴心所确定的绝对角动量(AAM)是分析和解释热带气旋动力学的有价值的、准守恒的工具。如果没有丰富而有效的气旋性AAM,也没有足量的AAM输送到中心以补偿所有的内部汇,气旋就不能形成或维持。所以研究气旋性角动量输入热带气旋的方式,可以提供对热带气旋起作用的那些重要的复杂机制的有     

Ab Initio Molecular Dynamic Simulation on the Elasticity of Mg_3Al_2Si_3O_(12) Pyrope

We calculated thermo-elastic properties of pyrope(Mg3Al2Si3O12) at mantle pressures and temperatures using Ab initio molecular dynamic simulation.A third-order Birch-Murnaghan equation at a reference temperature of 2 000 K fits the calculations with bulk modulus,K0=159.5 GPa,K0'=4.3,V0=785.89 A3,Grüneisen parameter,γ0=1.15,q=0.80,Anderson Grüneisen parameter δT=3.76 and thermal expansion,α0=2.93×10-5 K-1.Referenced to room temperature,where V0=750.80 A3,γ0 and α0 become 1.11 and 2.47×10-5 K-1.The elastic pr...     

Homochirality as the signature of life: the SETH Cigar

A characteristic hallmark of life is its homochirality: all biomolecules are usually of one hand, e.g. on Earth life uses only L-amino acids for protein synthesis and not their D mirror images. It is therefore suggested that a search for extra-terrestrial life can be approached as a Search for Extra-Terrestrial Homochirality (SETH). A novel miniaturized space polarimeter, called the SETH Cigar, is described which could he used to detect optical rotation as the homochiral signature of life on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. It is believed that homochirality will be found in the subsurface layers on Mars as a relic of extinct life.     

Dicroerisma （Actiniscales,Dinophyceae） in the open Pacific Ocean,a gymnodinioid dinoflagellate with an endoskeleton

This study is the first to describe and illustrate the dinoflagellate genus Dicroerisma in the open Pacific Sea and in the southern hemisphere. Eleven individuals ascribed to Dicroerisma psilonereiella were encountered in subsurface waters （〉70 m depth） from 34°N to 33°S. Another specimen that differs from the type is also illustrated. These findings reveal that Dicroerisma is a widespread genus and that there is tentative existence of another species within the genus.     

Evidence for a Black Hole and Accretion Disk in the LINER NGC 4203

We examine the supernova remnant SNR 0540-697 in the Large Magellanic Cloud (LMC) using data from the Chandra Advanced CCD Imaging Spectrometer. The X-ray emission from this supernova remnant (SNR) had previously been hidden in the bright emission of the nearby X-ray binary LMC X-1; however, new observations with Chandra can finally reveal the SNR's structure and spectrum. We find the SNR to be a thick-shelled structure about 19 pc in diameter, with a brightened northeast region. Spectral results suggest a temperature of 0.31 keV and an X-ray luminosity (0.3-3.0 keV) of 8.4x1033 ergs s(-1). We estimate an age of 12,000-20,000 yr for this SNR, but note that this estimate does not take into account the possibility of cavity expansion or other environmental effects.     

PETROLEUM HYDROCARBON CONTAMINATION OF GROUND WATER IN TIVERTON, RHODE ISLAND, USA

Ground water samples from several private wells serving individual homes in Tiverton, Rhode Island were analyzed for petroleum contamination over a 19-month period. The hydrocarbon concentrations initially ranged from 68 to 2350 ppb and then gradually decreased to lower values, ranging from 6 to 1650 ppb, at the end of the study.Samples from the well with the highest hydrocarbon concentration (2350 to 1650 ppb) were investigated in some detail because this was considered a possible source of the petroleum contamination in the area. These studies indicated that most of the hydrocarbons were in the dissolved phase (< 1.0um) of the ground water and that it contained large amounts of naphthalene, methyl and dimethyl naphthalenes, and ethyl naphthalenes. In addition, the qualitative distribution of hydrocarbons changed as the concentration decreased over the course of the investigation. There appeared to be preferential loss of the more volatile and easily degraded components relative to the higher molecular     

Nonlinear time series analysis of the light curves from the black hole system GRS 1915+105

GRS 1915+105 is a prominent black hole system exhibiting variability over a wide range of time scales and its observed light curves have been classified into 12 temporal states. Here we undertake a complete analysis of these light curves from all the states using various quantifiers from nonlinear time series analysis, such as the correlation dimension (D2), the correlation entropy (K2), singular value decomposition (SVD) and the multifractal spectrum (f(α) spectrum). An important aspect of our analysis is ...