近50年来中国西北地区干湿状况时空分布

根据西北地区77个气象台站气候资料,并利用改进的Penman公式,计算了该地区1958年~2001年的44年平均潜在蒸散量的时空分布,并分析了与降水量变化之间的关系,得到4种类型潜在蒸散量与降水量年际变化的组合分布型。其中年平均潜在蒸散量减小而年降水量增大的组合占研究区站点总数的40%以上。分析潜在蒸散量及观测蒸发量与各气候因子的相关性,发现干旱区的蒸发与太阳辐射和风速有关。定义干燥指数为潜在蒸散量与降水量的比值,用来描述西北干旱区的干湿状况。对干旱区四个季节(春、夏、秋、冬)干燥指数近50年的线性变化趋势分析结果显示,干旱区春季大部分区域干燥指数呈增加趋势,即趋于变干;夏季大部分地区趋于变湿,但仅在新疆东部和甘肃西部较为明显;秋季新疆大部、甘肃西部和青海北部等地区趋于变湿,而干旱区东部区域则趋于变干。冬季干旱区大部分区域趋于变湿,只有新疆西南部和西北部及东部部分地区、甘肃西部和内蒙西部等地有变干趋势。     

地质钻探过程状态监测App软件设计与应用

区域钻场数据监测对地质钻探过程的控制和决策具有重要意义。为解决当前大多数钻探过程状态监测系统存在的钻孔数据单一、数据互联不通以及缺乏远程便携式监测软件等问题,结合移动通信和互联网技术,开发一款基于Android的地质钻探过程状态监测App。该App整体采用模型-视图-演示器架构进行设计,具有实时监测、历史曲线趋势分析等一系列功能。在辽宁丹东3000 m科学钻探工程现场投入使用,取得了良好的状态监测效果。该App可实时获取钻进过程状态信息,并及时提醒专家进行操作调节与决策,为地质钻探施工提供很大的便利。     

Proof of the equivalence of Tanizawa–Berkvens’ and Cointe–van Daalen's formulations for the time derivative of the velocity potential for non-linear potential flow solvers

Dealing with freely-floating bodies in the framework of non-linear potential flow theory may require solving Laplace's equation for the time derivative of the velocity potential. At present, there are two competing formulations for the body boundary condition. The first one was derived by Cointe [1] in 2D. It was later extended to 3D by van Daalen [2]. The second formulation was derived by Tanizawa [3] in 2D. It was extended to 3D by Berkvens [4]. In this paper, a proof is given that the Cointe–van Daalen's and the Tanizawa–Berkvens’ formulations are equivalent. It leads to a simplified version of Cointe–van Daalen's formulation. The formulation is validated against the analytical solution for a moving sphere in an unbounded water domain.     

Convection in a rotating magnetic system and taylor's constraint part II,numerical results

Abstract

Results are presented of a numerical study of marginal convection of electrically conducting fluid, permeated by a strong azimuthal magnetic field, contained in a circular cylinder rotating rapidly about its vertical axis of symmetry. To this basic state is added a geostrophic flow U_G (s), constant on geostrophic cylinders radius s. Its magnitude is fixed by requiring that the Lorentz forces induced by the convecting mode satisfy Taylor's condition. The nonlinear mathematical problem describing the system was developed in an earlier paper (Skinner and Soward, 1988) and the predictions made there are confirmed here. In particular, for small values of the Roberts number q which measures the ratio of the thermal to magnetic diffusivities, two distinct regions can be recognised within the fluid with the outer region moving rapidly compared to the inner. Otherwise, conditions for the onset of instability via the Taylor state (U_G 0) do not differ significantly from those appropriate to the static (U_G = 0) basic state. The possible disruption of the Taylor states by shear flow instabilities is discussed briefly.     

南昆线八渡K343滑坡的工程地质条件及治理研究

地质与物探综合研究表明 ,八渡滑坡是由于砂岩强风化层顶部富含高岭土等矿物 ,暴雨后饱水变为易流层 ,引起强风化和松散层重力失稳。滑动体厚度 2 0m左右 ,滑动面积近 3万m2 ,滑动体积约 6 0万m3 。在查清了地质条件的基础上 ,提出了抗滑与治水并重的治理方案.     

Modelling the spectral response of the desert tree Prosopis tamarugo to water stress

In this paper, we carried out a laboratory experiment to study changes in canopy reflectance of Tamarugo plants under controlled water stress. Tamarugo (Prosopis tamarugo Phil.) is an endemic and endangered tree species adapted to the hyper-arid conditions of the Atacama Desert, Northern Chile. Observed variation in reflectance during the day (due to leaf movements) as well as changes over the experimental period (due to water stress) were successfully modelled by using the Soil-Leaf-Canopy (SLC) radiative transfer model. Empirical canopy reflectance changes were mostly explained by the parameters leaf area index (LAI), leaf inclination distribution function (LIDF) and equivalent water thickness (EWT) as shown by the SLC simulations. Diurnal leaf movements observed in Tamarugo plants (as adaptation to decrease direct solar irradiation at the hottest time of the day) had an important effect on canopy reflectance and were explained by the LIDF parameter. The results suggest that remote sensing based assessment of this desert tree should consider LAI and canopy water content (CWC) as water stress indicators. Consequently, we tested fifteen different vegetation indices and spectral absorption features proposed in literature for detecting changes of LAI and CWC, considering the effect of LIDF variations. A sensitivity analysis was carried out using SLC simulations with a broad range of LAI, LIDF and EWT values. The Water Index was the most sensitive remote sensing feature for estimating CWC for values less than 0.036 g/cm², while the area under the curve for the spectral range 910–1070 nm was most sensitive for values higher than 0.036 g/cm². The red-edge chlorophyll index (CI_red-edge) performed the best for estimating LAI. Diurnal leaf movements had an effect on all remote sensing features tested, particularly on those for detecting changes in CWC.     

灵丘苦荞麦生态分布的气象条件

利用分区试验观测数据和2004—2013年近10年灵丘县3个区域的月平均气温、月平均降水量和无霜期日数等资料,结合走访调查结果,分析灵丘县苦荞麦生态分布与气象条件的相关性。结果表明,北山区是灵丘县适合苦荞种植的主要区域,该区域海拔较高,无霜期较短,气候凉爽,风速较大,这种小气候特征与苦荞麦生长发育习性相吻合。南山区和川下区海拔较低,无霜期较长,气候温湿,风速较低,加上人均耕地较少,苦荞麦种植以救灾填闲为主。研究气象条件对苦荞麦生态分布的影响,结合科学的田间管理,对灵丘县苦荞麦生产向优质化、产业化和规模化发展具有重要意义。     

山东省栖霞市苇夼金矿床地质特征

栖霞市苇夼金矿床赋存于燕山早期郭家岭超单元二长花岗岩中,矿化严格受北东向构造控制,主要由黄铁绢英岩化糜棱岩和黄铁绢英岩化碎裂岩组成,矿体呈脉状、透镜状。该区从构造、岩石、蚀变等控矿条件分析,是一个具有金成矿远景的地区。     

吐哈盆地台北凹陷侏罗系油气富集地质条件及油气分布规律

分析了吐哈盆地台北凹陷侏罗系油气富集地质条件,探讨了其油气分布规律,指出了今后油气勘探的方向。4套2类良好的油源、多套储集性能良好的砂体、有效的圈闭、2套封盖性能极好的区域性盖层及优越的生储盖组合配置是油气富集的基本地质条件;构造、构造—岩性复合是主要的油气藏类型;环主力生油凹陷、沿短轴分布的砂体与燕山期的古构造及喜山期改造加强的构造叠置、多期活动的油源断裂控制油气是油气分布聚集的规律;中部凹陷区的深挖细找,山前褶断带、火焰山背斜带及逆冲断裂上下盘构造,是今后油气勘探的方向。     

复杂地质条件下钻探卡心与取样技术

从卡取岩心和采集岩屑两种工具方面探讨了复杂地质条件下的取心与取样问题;分析了我国常用的卡心工具在复杂地质条件下存在的问题;着重介绍了俄罗斯的矩形环式、卡板式、卡箍式和卡瓦式4种专用卡心工具和孔底旋流岩屑采集装置,值得我国地质工作者在复杂地质条件下钻探取心和取样借鉴。