陕西驾鹿金矿床地质特征及成因探讨

驾鹿金矿床是小秦岭金矿带中一个比较特殊的矿床类型，产于古老韧性剪切带中，围岩蚀变强烈而广泛，尤其是成脉前的钾长石化。蚀变带及其中的石英脉控制了金矿体的产出，矿床属蚀变岩型金矿，成矿时代为燕山晚期．本文在论述矿床地质特征的基础上，通过稳定同位素研究，认为燕山期构造热事件是成矿的主导控制因素，成矿溶液来自大气降水，成矿物质则部分来自太华群，部分来自上覆中元古界高山河组，矿床成因属大气降水热液矿床．     

Intermittent Bursting of Turbulence in a Stable Boundary Layer with Low-level Jet

The atmospheric stable boundary layer (SBL) with a low-level jet is simulated experimentally using a thermally stratified wind tunnel. The turbulence structure and flow characteristics are investigated by simultaneous measurements of velocity and temperature fluctuations and by flow visualization. Attention is focused on the effect of strong wind shear due to a low-level jet on stratified boundary layers with strong stability. Occasional bursting of turbulence in the lower portion of the boundary layer can be found in the SBL with strong stability. This bursting originates aloft away from the surface and transports fluid with relatively low velocity and temperature upward and fluid with relatively high velocity and temperature downward. Furthermore, the relationship between the occurrence of turbulence bursting and the local gradient Richardson number (Ri) is investigated. The Ri becomes larger than the critical Ri, Ri_cr = 0.25, in quiescent periods. On the other hand, the Ri number becomes smaller than Ri_cr during bursting events.     

胶南地区的伸展作用——以胶南—诸城一带为例

胶南地区的胶南—诸城一带存在两期不同方向的伸展构造。早期以形成近ＥＮ向的拉伸线理为特征，并在不同构造层次上显示出不同的变形。出露于研究区中部桃林尚庄隆起的含榴辉岩片麻岩中，主要以ＬＳ的组构为特征，显示出早期伸展作用下地壳岩石的垂直轴缩短、ＥＷ向拉伸的共轴应变；而在把下地壳含榴辉岩片麻岩与以变沉积岩为主的中上地壳岩石分开的韧性滑脱带上，此期伸展作用则表现为从东向西剪切的非共轴简单剪切变形，具有近水平的拉伸线理及近水平的ＥＷ向剪切褶皱和鞘褶皱枢纽。晚期伸展作用表现为近ＳＮ的伸展垮塌作用，形成向北和向南倾斜的两条韧性正剪切带，且遭受低角闪岩高绿片岩相条件下的透入性均匀简单剪切变形，剪切方向分别向北和向南。     

The crustal fluid evolution and the causes of earthquakes(Ⅲ)

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山东地区地壳速度与中强地震的关系

利用山东区域地震数字台网提供的数据,通过三维层析成像方法结合山东地质构造实际情况,对山东区域进行联合走时反演地壳速度结构,获得该区分辨率较高的三维速度结构图像。结果表明：不同深度上的速度分布反映出山东地区深部构造的某些重要信息,为进一步研究该区的活动构造及地震参数计算提供科学依据。在地壳速度结构与中强地震活动的关系上,再次显示出中强震多发生在速度结构高速单元与低速单元的过渡带附近,说明中强震的孕育与震源区周围介质的不均匀性有关。     

On the Spatial Distribution and Seasonal Variation of Lower-Troposphere Ozone over Europe

Surface ozone data from 25 Europeanlow-altitude sites and mountain sites located between79°N and 28°N were studied. The analysiscovered the time period March 1989–February 1993.Average summer and winter O₃ concentrations inthe boundary layer over the continent gave rise togradients that were strongest in the north-west tosouth-east direction and west-east direction, respectively. WintertimeO₃ ranged from 19 to 27 ppbover the continent, compared to about 32 ppb at thewestern border, while for summer the continentalO₃ values ranged between 39 and 56 ppb and theoceanic mixing ratios were around 37 ppb. In the lowerfree troposphere average wintertime O₃ mixingratios were around 38 ppb, with only an 8 ppbdifference between 28°N and 79°N. For summerthe average O₃ levels decreased from about 55 ppbover Central Europe to 32 ppb at 79°N. Inaddition, O₃ and O_x(= O₃ + NO₂)in polluted and clean air were compared. Theamplitudes of the seasonal ozone variations increasedin the north-west to south-east direction, while thetime of the annual maximum was shifted from spring (atthe northerly sites) to late summer (at sites inAustria and Hungary), which reflected the contributionof photochemical ozone production in the lower partsof the troposphere.     

雅鲁藏布江深厚砂砾卵石覆盖层钻探工艺

为了开展雅鲁藏布江流域综合规划及其水资源开发利用与保护专题研究工作,在雅鲁藏布江干流里龙坝址和本宗坝址共布置了4个200~300 m深的钻孔。主要通过在西藏高寒地区4个深厚覆盖层钻孔的成功实施经验,对西藏高寒地区深厚覆盖层勘探成孔工艺与技术进行研究探讨。     

镇江市矿产资源规划数据库建设创新探讨

在MapGIS平台,采用关系数据库模型,建设镇江市矿产资源规划数据库,形成较为完整的矿产资源规划数据库的图层内容、属性结构、属性内容、属性字段,为江苏全面开展各市县矿产资源规划数据库建设起到指导示范作用。     

Simulation of the ocean surface mixed layer under the wave breaking

A one-dimensional mixed-layer model, including a Mellor-Yamada level 2.5 turbulence closure scheme, was implemented to investigate the dynamical and thermal structures of the ocean surface mixed layer in the northern South China Sea. The turbulent kinetic energy released through wave breaking was incorporated into the model as a source of energy at the ocean surface, and the influence of the breaking waves on the mixed layer was studied. The numerical simulations show that the simulated SST is overestimated in summer without the breaking waves. However, the cooler SST is simulated when the effect of the breaking waves is considered, the corresponding discrepancy with the observed data decreases up to 20% and the MLD calculated averagely deepens 3.8 m. Owing to the wave-enhanced turbulence mixing in the summertime, the stratification at the bottom of the mixed layer was modified and the temperature gradient spread throughout the whole thermocline compared with the concentrated distribution without wave breaking.     

Study on Effects of Building Morphology on Urban Boundary Layer Using an Urban Canopy Model

An urban canopy model is incorporated into the Nanjing University Regional Boundary Layer Model. Temperature simulated by the urban canopy model is in better agreement with the observation, especially in the night time, than that simulated by the traditional slab model. The coupled model is used to study the effects of building morphology on urban boundary layer and meteorological environment by changing urban area, building height, and building density.It is found that when the urban area is expanded, the urban boundary layer heat flux, thermal turbulence, and the turbulent momentum flux and kinetic energy all increase or enhance, causing the surface air temperature to rise up. The stability of urban atmospheric stratification is affected to different extent at different times of the day.When the building height goes up, the aerodynamic roughness height, zero plane displacement height of urban area, and ratio of building height to street width all increase. Therefore, the increase in building height results in the decrease of the surface heat flux, urban surface temperature, mean wind speed, and turbulent kinetic energy in daytime. While at night, as more heat storage is released by higher buildings, thermal turbulence is more active and surface heat flux increases, leading to a higher urban temperature.As the building density increases, the aerodynamic roughness height of urban area decreases, and the effect of urban canopy on radiation strengthens. The increase of building density results in the decrease in urban surface heat flux, momentum flux, and air temperature, the increase in mean wind speed, and the weakening of turbulence in the daytime. While at night, the urban temperature increases due to the release of more heat storage.