合肥地震台地下电性层研究

本文介绍在合肥台地电布极区进行十字电测深的勘选测量方法,根据电测深数据反演观测场地地下介质电性结构,就多解性问题进行了讨论。     

塔克拉玛干沙漠北部全新世环境演变（Ⅰ）

通过对塔克拉玛干沙漠北部，塔里木河泛滥平原典型剖面的沉积物粒度特征、化学元素的变化和沉积相特征的研究，并结合~（１４）Ｃ测年，揭示了本区域全新世以来的环境变化规律，本区全新世以来的多风、高温、干燥的气候形成是以全球气候波动为背景，叠加内陆干旱封闭盆地影响而成的。但在干燥气候条件下曾有过几次空气湿度较大的偏湿期。本区沉积相主要以河流冲积作用形成的粘土层和风力作用下形成的风砂层为主，剖面中的亚粘土与现代河流相特征一致，剖面中风砂土与现代流沙性质趋同。全新世以来本区共发生３次明显的河流泛滥期，可以同全新世以来的间冰期对应。     

臭氧层减少对沿海地区大气温度与环境的影响

利用青岛市连９年的主空探测资料，分析也大气温度的变化与高空臭氧层有关，高层气温与地面气温呈负相关变化。高空臭氧减少，使沿海地区温度梯度加大，在不我向时可能造成大气污染加重，暖气团辐合上升，易将大气污染物挟带支支中，当酸性物大于碱性物时形成酸雨，产生一系大气环境问题。     

Application of ground-based Lidar for studies of the dynamics of ozone in a mountainous basin

A ground-based Differential Absorption Lidar was employed to study the dynamics of atmospheric O3 within the planetary boundary layer of a basin in the 'Fichtelgebirge' mountains, NE Bavaria. In particular, the night-time dynamics of O3 linked to the ground were investigated. The Lidar system measured vertical profiles of O3 up to 1 km above ground. For detailed analysis of the night-time dynamics of ozone, supplementary data from three ground-based stations (measuring mixing ratios of O3 and NO(x), as well as meteorological parameters) are essential. The Lidar results could be evaluated with these data from various altitudes above the basin floor. For the station with the largest (vertical) distance to the ground-based Lidar, the agreement was very good at all times. The Lidar method proved to be useful for examining the spatial distribution of O3. The observed night-time decrease of O3 at the bottom of the basin was due to deposition and to advection of air masses containing less O3 from the mountain slopes.     

Turbulence closure models and their application in RAMS

Turbulence closures are fundamental for modelling the atmospheric diffusion in numerical codes and the resulting eddy diffusivities are key parameters in describing the transport and dispersion in the boundary layer. In this work, four turbulence closure schemes have been applied for reproducing a neutral flow over schematic complex terrain using the meteorological model RAMS. Two of the closures, a one-equation (E-l) and a two-equations (E-) model, have been implemented in RAMS in alternative to the ones originally available. In these cases, an analytical method based on the similarity theory for the atmospheric surface layer and boundary layer is adopted to calculate the empirical constants of the turbulence closures. Some examples of numerical studies performed to simulate the flow and turbulence over a 3-D hill in wind-tunnel experiment in neutral stratification are presented and discussed. An intercomparison of simulations related to different closures is considered by analysing the main features of the flow over the hill and by comparing calculated vertical profiles of turbulent kinetic energy with measured ones.     

超细粉尘的扬尘机理研究

针对目前对于一般尘源控制研究较少,而系统研究粉尘的扬尘(尘化)机理的研究就更少这一状况,提出弄清尘化机理、从源头上控制是治理粉尘的首要问题,对粉尘颗粒作用力进行分析,特别就超细粉尘的扬尘机理提出相应的物理模型并进行初步研究.图1,参2.     

Observations of the cross-wind velocity variance in the stable boundary layer

Nine tower datasets over grassland, brush rangeland, snow covered plain, the ocean, three different pine forests, an aspen forest and an urban site, are used to document the scale-dependence of the cross-wind velocity variance in the stable boundary layer. The turbulence velocity variance scales with the surface momentum flux, as reported in previous studies. Such scaling removes the stability dependence of the variance at a given site, and also removes most of the differences between sites. The scaling is more effective with use of a record-dependent averaging time for defining the turbulent fluctuations. The variable averaging time is the timescale associated with the gap region in the heat flux multiresolution cospectra. On scales larger than turbulence and less than a few hours (mesoscale), variations in the cross-wind velocity variance at a given site are not related to local variables such as the friction velocity. Possible exceptions include suppression of turbulence and mesoscale motions in well-defined drainage flows and enhancement of turbulence and mesoscale motions in stronger winds downstream of a ridge. Larger mesoscale variance is associated with complex terrain and forested sites compared to the more homogeneous sites in flat terrain with short or no vegetation. These differences between sites are related to the absence of a gap region in the velocity spectra at the complex terrain and forested sites. The observed probability distribution functions of the total variance and the mesoscale variance are documented for different averaging times, stability classes and site characteristics.     

重庆雾的声雷达回波与大气SO2浓度的对比分析

本文分析了重庆１９８９年１２月３０日雾的声雷达回波特征与浓雾天气的关系，讨论了雾日大气ＳＯ２地面浓度状况。结果表明，声雷达回波与雾的定变有较好的对应；地面污染物浓度与声雷达回波所反应的大气层结状况关系密切，３００－４００米高度上的逆温层维持较长时间是加重当日大气ＳＯ２地面浓度的重要原因。     

超细三七粉最小引燃温度实验研究

为研究三七粉着火燃烧的参数,用粉尘云引燃温度装置和粉尘层引燃温度装置,对三七粉的最小引燃温度(MIT)进行实验研究。分别研究喷吹压力、质量浓度、粉尘层厚度对MIT的影响。结果表明:三七粉尘云的质量在0.2 g时最小引燃温度随着喷尘压力的增加先减小再增大,在0.3 g到0.6 g时最小引燃温度随着喷尘压力的增加而增大;在压力20 kPa、30 kPa时随着质量浓度的增大,粉尘云引燃温度先减小后增大,在40 kPa到60 kPa时,随着质量浓度的增大,粉尘云引燃温度增大;粉尘云最小引燃温度高于粉尘层最小引燃温度;三七粉尘云的最小引燃温度399℃,粉尘层最小引燃温度240℃。     

The effect of admixed material on the flaming and smouldering combustion of dust layers

The rate of propagation of flame and the rate of propagation of smouldering in still air, have been investigated for several particle sizes, mixtures of coarse and fine dusts of the same material, and mixtures containing partially coarse dusts of limestone. Wood sawdust and grass dust were used as the industrial materials. Measurements were made by using a mold of acceptable dimensions. The results obtained indicated that the flaming and smouldering rates are dependent on the particle size and the depth of the layer and the values of the smouldering rates were found to be about 20% of the values obtained with flaming. Also, an admixture of fine dust of 50% of the same material to coarse dust for a 0.5 cm layer of both materials is sufficient to increase the values of the flaming rate by 61% for wood sawdust and the smouldering rate by 88% and 52% for wood sawdust and grass dust, respectively. The admixture of limestone as low as 10% was sufficient to produce zero propagation for both types of burning.