Observations And Modelling Of The On-Ice And Off-Ice Air Flow Over The Northern Baltic Sea

Two cases of on-ice and off-ice air flow characterizing the opposite weather situations over the ice-edge zone in the northern Baltic Sea are analysed on the basis of aircraft observations, and modelled using atwo-dimensional mesoscale model. The stable boundary layer (SBL) during theon-ice flow exhibited little thermal modification, but a low-level jet (LLJ) was generated at the 250-m high top of the SBL. In the model, the LLJ was associated with inertial oscillations in space, while the baroclinicity explained the shape of the wind profile well above the SBL. Although the observed LLJ was most pronounced over the ice, the modelling suggests that it was not generated by the ice edge but by the coastline some 400 km upwind of the ice edge, where a much more drastic change in the thermal stratification and surface roughness took place. The generation, maintenance, and strength of the LLJ were very sensitive to the parameterization of turbulent mixing in the SBL. In the case of the off-ice flow, the modification of the air mass and the development of a convective boundary layer (CBL) both over the ice and open sea were reasonably well modelled. Sensitivity runs suggested that it was essential to take into account the effects of subgrid-scale leads, a forest in the archipelago (which was crossed by the air flow), and water vapour condensationinto ice crystals. The heat flux from leads was particularly important for the heatbudget of the CBL, and the observed growth of the CBL was partly due to theeffective mixing over the rough and relatively warm forest.     

铜陵天马山硫金矿床地质特征及成因探讨

天马山硫金矿床的矿体分为层状矿体、接触带矿体和穿层矿体。层状矿体和穿层矿体受石炭系黄龙组、船山组地层层位和层间断裂控制。接触带矿体受接触带控制 ,具矽卡岩型矿体典型特征。矿床的形成受地层、构造及岩浆岩控制 ,矿床成因为层控矽卡岩型硫金矿床     

Analyzing CO2 emissions mitigation by technology improvement in Central and Eastern Europe

As a legacy of the centrally planned economy, the economies in transition of Central and Eastern Europe (CEE) have a unique potential to reduce their greenhouse gas emissions through the improvement in their high energy intensities. Since much of this `low-hanging fruit' in energy-efficiency improvements can be highly cost-effective, many developed countries facing difficulties in meeting their greenhouse gas (GHG) emission targets domestically are eager to find such opportunities in the CEE region. Therefore, studies analysing the potentials and costs of carbon dioxide reduction through technology improvement in the region have come into the limelight. While there are a few excellent studies in the region aimed at analysing climate change abatement potentials, they all embark on different assumptions, methodologies and boundary conditions. It is hence difficult, if not impossible, to compare and analyse the results of these studies across different authors, countries or time horizons. Consequently, the purpose of this paper is to place four leading studies on GHG mitigation through technology improvement from the CEE region into an internationally comparable framework. Four studies were selected from three countries, Poland, Hungary and Estonia, which are all the results of major national and international efforts to assess costs and potentials of GHG reduction. The paper places their assumptions, methods and final results into a framework which enables policy-makers and project designers to compare these across geographical and technological boundaries. Since other studies from around the globe have been analysed in this framework in the literature, this paper provides a vehicle for the findings of these four studies to be compared to others worldwide. In addition, the paper highlights a few areas where similar studies to be completed in the future in the region may be enhanced by incorporating features used in GHG mitigation research in other parts of the world. This revised version was published online in July 2006 with corrections to the Cover Date.     

兰坪白秧坪铜银多金属矿床成矿物质来源的铅和硫同位素示踪

白秧坪铜银多金属矿床主要产于白垩系下统景星组石英砂岩、粉砂岩中，矿石铅同位素组成特征与景星组砂岩的铅同位素组成比较接近，表明壳源物质参与了成矿作用。作ZartMan图解和△γ—△β图解表明，矿石铅属于壳幔混合来源。矿石铅μ值介于9．43—9．65之间，Th/U比值介于3．72—3．87之间，表明矿石铅为壳幔混合铅。该矿床硫同位素组成表明，硫来源于深部地幔硫遭受地壳硫的混入。该矿床的成矿作用发生于开放体系之中，成矿物质来源为深部幔源物质混合了壳源物质。     

An Experimental Calibration on the Sphalerite-Galena Sulfur Isotope Geothermometer

A new experimental calibration was undertaken in this study to get a more reliable sphalerite-galena sulfur isotope geothermometer. The experimental conditions selected in study were very similar to those of natural hydrothermal solution. The high-precision SF6 method was used in sulfur isotope analyses. The obtained calibration curve for sulfur isotope fractionation between sphalerite and galena can be expressed with the equation 10001nαSp-Gn= 0.74×106T-2+0.08.     

Geochemical Characteristics of Gold Polymetallic Deposits as Exemplified by the Laozuoshan Deposit,Heilong jiang,China

From the studies of ore deposit geologic settings,sulfur isotopes,lead isotopes,carbon isotopes and oxygen isotopes,fluid inclusions and petrochemistry in this paper,the authors have drawn a conclusion that the ore-forming hydrothermal solutions are the high-temperature magmatic hydrothermal solutions for the gold ore deposit,and at the same time,the involvemety of crustal materials can not be ruled out .It is the first time that the authors have proposed that the Laozuoshan gold-ploymetallic ore deposit in Heilongjiang Province was formed in the calc-alkaline series environment at the margin of an active continent.     

Monitoring volcanic hazard using eddy covariance at Solfatara volcano, Naples, Italy

An eddy covariance (EC) station was deployed at Solfatara crater, Italy, June 8–25, 2001 to assess if EC could reliably monitor CO₂ fluxes continuously at this site. Deployment at six different locations within the crater allowed areas of focused gas venting to be variably included in the measured flux. Turbulent (EC) fluxes calculated in 30-min averages varied between 950 and 4460 g CO₂ m⁻² d⁻¹; the highest measurements were made downwind of degassing pools. Comparing turbulent fluxes with chamber measurements of surface fluxes using footprint models in diffuse degassing regions yielded an average difference of 0% (±4%), indicating that EC measurements are representative of surface fluxes at this volcanic site. Similar comparisons made downwind of degassing pools yielded emission rates from 12 to 27 t CO₂ d⁻¹ for these features. Reliable EC measurements (i.e. measurements with sufficient and stationary turbulence) were obtained primarily during daytime hours (08:00 and 20:00 local time) when the wind speed exceeded 2 m s⁻¹. Daily average EC fluxes varied by ±50% and variations were likely correlated to changes in atmospheric pressure. Variations in CO₂ emissions due to volcanic processes at depth would have to be on the same order of magnitude as the measured diurnal variability in order to be useful in predicting volcanic hazard. First-order models of magma emplacement suggest that emissions could exceed this rate for reasonable assumptions of magma movement. EC therefore provides a useful method of monitoring volcanic hazard at Solfatara. Further, EC can monitor significantly larger areas than can be monitored by previous methods.     

Kinetics of Disproportionation of Inorganic Polysulfides in Undersaturated Aqueous Solutions at Environmentally Relevant Conditions

The rate of the reversible homogeneous disproportionation of polysulfides was studied by following the optical absorbance of polysulfide solutions in a continuous plug flow reactor equipped with an on-line photometric detector. In order to avoid heterogeneous slow reactions involving sulfur colloids or precipitate, the reaction was initiated by an abrupt pH change from an undersaturated solution containing predominantly tetrasulfide species to a pH where pentasulfide is the dominant species. The disproportionation was found to follow first order reversible reaction dynamics. At environmentally relevant conditions the characteristic time of the disproportionation reaction is of the order of 10 s. This characteristic time implies that necessary conditions for speciation of the different polysulfide species by chromatography or another separation and subsequent quantification scheme should be of the order of 1 s.     

农田生态系统大气硫沉降通量的观测研究

1998年 11月～ 1999年 10月间在中国科学院红壤站 (江西鹰潭 )农田小气候站进行了大气二氧化硫 (SO2 )、硫酸盐粒子 (SO2 -4)浓度采样和雨水样本收集 ,利用阻力模式和全年逐时气象资料计算 SO2 和 SO2 -4的干沉降速度 ,估算干沉降通量 ,利用降水资料和雨水中硫酸根离子浓度估计大气硫的湿沉降 ,从而定量研究大气硫沉降输入农田生态系统的通量 ,结果表明 :农田下垫面上 SO2 和 SO2 -4干沉降速度的年平均值分别是 0 .373± 0 .170 cm· s-1(月均值 0 .16 1～ 0 .5 45 cm·s-1)、0 .198± 0 .12 3cm· s-1(月均值 0 .15 2～ 0 .2 6 9cm· s-1)。农田下垫面硫年总沉降量为 10 .3g· m-2 ,其中干沉降占总沉降的 83.3%。硫的干沉降又以 SO2 的干沉降为主 ,占年干沉降总量的 92 .2 %。大气硫沉降输入占农田生态系统输入总量的 90 %以上 ,是农田生态系统获取硫素的一个重要途径