SPECTRUM期间目标台风移动的数值试验

在目标台风Ｙａｎｃｙ的移动过程中，选择４个时段进行预报数值试验。模式初始场系根据ＳＰＥＣＴＲＵＭ和ＴＣＭ－９０加强观测资料确定。结果表明：实际大气中目标台风移动的若干特征在模式大气中能够显示出来，如Ｙａｎｃｙ在１９９０年８月２０日００时移向的转折现象等；台风非对称结构的低频振荡是产生移向转折现象的一个重要原因。     

Field compaction control studies on road bases in a new settlement area in Ghana

Summary Among the major causes for failure of roads in the tropics is inadequate compaction during construction. There is, therefore, the need to strictly control the compaction of the pavement layers if the design life of the road is to be attained; thereby eliminating large maintenance costs.This note reports on pavement compaction control studies undertaken on the road bases of service roads in a new settlement area in Ghana. These roads were to be provided with bituminous surfacing immediately after compaction. Studies concerning particle breakdown during field compaction by two contractors executing the works under the same conditions have been made, together with an assessment of contractor efficiency.It was found that the placement moisture contents varied greatly from the optimum. One contractor was compacting the gravels on the dry side of optimum, consequently achieving relatively high densities. The other contractor was compacting on the wet side and achieving lower density levels. This was still the case even after initial test sections were found to have been undercompacted.Compaction levels achieved in the crowns were generally found to be higher than those at the shoulders of the road test sections. The breakdown of coarse particles due to compaction was quite significant. There is therefore the need for highway material engineers to ensure that in addition to meeting the grading requirements, road base materials must adequately meet the requirements on weathering and mechanical strength properties.     

通过对调查数据的趋势和多变量分析确定宏观场

通过多变(相关分析)和趋势分析等统计方法对宏观调查数据进行了解释.这种方法使我们通过评定不同宏观效应叠加的程度、估计调查数据的不确定性更客观地评定烈度.通过滤波确定烈度场的区域分量,使我们消除观测中的局部变化.给出了选取适当滤波参数的准则.本文应用这一方法对发生在意大利的一次地震的调查数据进行了处理.     

兰州—天水地区三维重力反演及其地质解释

本文利用重力资料对兰州—天水地区的深部构造进行了研究。在计算中,采用Parker-Oldenbarg三维位场反演方法,反演前对重力资料进行了地形改正和中新生代沉积层校正。根据反演结果,综合分析了有关资料,认为该区为青藏块体过渡带,并且提出了陇中盆地为断块型构造盆地的新认识。     

Evaluation of pre-CHAMP gravity models `GRIM5-S1' and `GRIM5-C1' with satellite crossover altimetry

 The new GFZ/GRGS gravity field models GRIM5-S1 and GRIM5-C1, currently used as initial models for the CHAMP mission, have been compared with other recent models (JGM 3, EGM 96) for radial orbit accuracy (by means of latitude lumped coefficients) in computations on altimetry satellite orbits. The bases for accuracy judgements are multi-year averages of crossover sea height differences from Geosat and ERS 1/2 missions. This radially sensitive data is fully independent of the data used to develop these gravity models. There is good agreement between the observed differences in all of the world's oceans and projections of the same errors from the scaled covariance matrix of their harmonic geopotential coefficients. It was found that the tentative scale factor of five for the formal standard deviations of the harmonic coefficients of the new GRIM fields is justified, i.e. the accuracy estimates, provided together with the GRIM geopotential coefficients, are realistic. Received: 20 February 2001 / Accepted: 24 October 2001     

坪北油田延长组长6油组储层层内非均质性研究

在坪北油田应用岩心观察、岩心分析化验资料、测井解释成果、测试及开发动态等方面的资料分析长6储层的非均质性,重点解剖层内非均质性特点,总结了正韵律,反韵律,复合韵律和交互韵律4种类型的层内非均质性。夹层分布较广泛,加剧了层间非均质性。     

华池油田长33低渗油藏流动单元研究

流动单元的研究,其目的在于对油藏的非均质性有进一步的认识,为提高油藏描述的精度提供依据。本文根据流动单元的理论,选取适合该区实际的参数,应用聚类判别分析的方法,对华池油田陇东地区长33低渗储层进行分类研究,并且分析各类流动单元的特征及其控制因素,得出结论:该区储层可分为三类流动单元,各类流动单元的判别公式,不同的类型在动态、静态上有不同的表现;其分布的差异,宏观上受沉积微相的控制,微观上受成岩作用、岩石自身储集空间特征的限制。     

大庆油田葡萄花油层组储层非均质性主控因素分析

本文对萨尔图油田中部葡萄花油层组的非均质性进行定量半定量研究,认为葡萄花油层组PⅠ2小层层内非均质性最严重,与沉积微相密切相关;单砂层垂向上渗透率的变化以正韵律和复合式韵律为主,局部发育反韵律模式;层内非均质性强弱依次为PⅠ2a、PⅠ3、PⅠ2b、PⅠ1、PⅠ4;层间非均质性在PⅠ3和PⅠ4间表现得最强,其它相对要弱;各小层平面非均质性相差无几,整体表现为较强的非均质性。     

民和盆地窑街煤田油页岩沉积环境分析及开发前景预测

通过岩芯钻井资料的综合分析,对民和盆地窑街煤田油页岩沉积特征、层序地层、古地理演化和成矿规律进行了研究。结果表明,油页岩段主要为水进体系域和高水位体系域发育时期,油页岩主要形成于沼泽和浅湖-半深湖相的沉积环境中。其中油四层油页岩品质较好,平均含油率>8%,属于湖泊沼泽相,具有良好的工业品位。研究区油页岩具有中含油率高灰分的特征,资源总储量为2.3×108t,具有良好的开发前景。     

A numerical study on 2-D compressive wave propagation in rock masses with a set of joints along the radial direction normal to the joints

An explosion in a borehole or an accidental explosion in a tunnel will generate a two-dimensional (2-D) compressive wave that travels through the surrounding rock mass. For the problem of 2-D compressive wave propagation in a rock mass with parallel joints in the radial direction normal to the joints, parametric studies on the transmission ratio and the maximum rebound ratio are performed in universal distinct element code. The variation of the transmission ratio with the ratio of joint spacing to wavelength is generalized into a characteristic curve, which can be used as a prediction model for estimating the transmission ratio. The relationship between the maximum rebound ratio and the influence factors is obtained in charts. The charts can be used as a prediction model for estimating the maximum rebound ratio. The proposed prediction models for estimating the transmission ratio and the maximum rebound ratio are applied to a field explosion test, Mandai test in Singapore. The minimum possible values of peak particle velocity (PPV) at the monitoring points are estimated by using the proposed prediction model for estimating the transmission ratio along the radial direction normal to the joints. On the other hand, the maximum possible values of PPV are estimated by using the proposed prediction model for estimating the maximum rebound ratio along the same radial direction. The comparison shows a good agreement between the field-recorded PPVs and the estimated range of PPVs given by the minimum possible PPVs and the maximum possible PPVs at the monitoring points in Mandai test. The good agreement between the estimated and field-recorded values validates the proposed prediction models for estimating peak particle velocity in a rock mass with a set of joints due to application of a compressive wave at the boundary of a tunnel or a borehole.