钻孔孔径的变化对γ测井解释含量的影响

钻孔孔径变化与矿床类型、钻进孔径、矿化岩性、矿层品位、矿层厚度、冲冼液的性质以及工程切穿矿层的时间有着密切的关系。孔径变化对γ测井解释含量、矿床储量的增减影响甚大。理论和实践证明,专门性的孔径测量,是提高γ测井质量、准确确定矿层品级的重要措施之一,对提高矿床经济效益也具有重要意义。     

我国部份地区雷暴活动、大气电场等与太阳活动的关系

本文用时序迭加法统计分析了1976—1985年太阳黑子一个完整周期内太阳活动与雷暴活动及地面大气电场之间的可能相关性。结果表明:高纬度地区有较好的相关性,耀斑爆发以后雷暴指数有明显增大趋势,最大关联日在+5日以后。中、低纬度地区几乎不存在相关性。随着耀斑强度增强,相关性也增大,且影响区域从高纬度向中、低纬度移动。在耀斑爆发后2天左右,地面电场强度增大,其关联日比雷暴指数提前。太阳黑子数和雷暴活动之间的相关性很微弱。本文又从全球电路概念出发,简单地解释了形成上述相关性的可能原因。     

A FUMIGATION DIFFUSION MODEL DURING THE MOUNTAIN-VALLEY WIND SHIFT PERIOD

The fumigation during the mountain-valley wind shift has been first identified as a special type of pol-lutant diffusion using the monitoring measurements of Dukou,Southwest Sichuan,China.Such a pheno-menon occurs frequently all year around but summer,particularly in winter months.A new model for thefumigation during the mountain-valley wind shift period is developed that allows satisfactory explanation ofthe fact.Analyses indicate that the model can more accurately predict not only the high concentration ofPollutants but the time and locality of the occurrence as well.The ground concentration of SO_2 during fumigation is several times up to over a decade higher thanthe daily mean for the whole region,one of the main contamination processes that affect the air quality ofthe city.The medel analyses provide a basis for more effective prediction of the quality and precautionstudy against the disaster.     

IMAGE PREDICTION FOR TORRENTIAL RAIN AREAS

A new method is presented for the prediction of a torrential rain (TR) area, where some atmo-physical parameters are used with their given values as criteria most favorable for the occurrence ofTR; an over-all examination is done of the relative favorabilities of these factors for the TR productionin other regions which are then composited and numeralized by means of the theory of nonlinearmapping with the results plotted (‘reflected') on a weather chart, allowing to make an objectiveforecast of the TR area. The preliminary results indicate that the technique is able to objectivelycomposite and clearly exhibit principal distribution features of the parameters on the map, thus show-ing a certain amount of effectiveness for the diagnosis and prediction of a TR area. Regression analysis is used for factor selection to automatically discriminate and locate the jet-stream axis with the aid of a computer. In the calculation of the mapping the gradient method isadopted, in the light of the functional properties of the optimized index K, in place of the simplerelaxational iteration now in general use, thus getting rid of the non-convergence by the iterationmethod because of the increased number of the samples used. The square of the gradient mod-ulus <10~(-4) is set to be the criterion for the iteration convergence. The improved method canmeet the requirements of operational forecasts generally with 50 or less iterations.     

THE NUMERICAL MODELING OF RADIATION FOG

The formation and development of radiation fog are studied by using a one-dimensional model.Theresults are as follows:(1)The fog can change the ambient wind and temperature fields,on the contrary,theambient fields may also influence the fog;(2)The modeling fog forms initially at a certain level above thesurface,which is detailedly explained in the paper;(3)Turbulence delays the formation of fog but promotesits development;(4)Whether fog liquid water content exchange coefficient equals momentum exchangecoefficient has no influence on the numerical results.In addition,wind,temperature,exchange coefficient,and net radiative flux before and after the formation of radiation fog,are also studied.     

钻孔走向偏斜的初步探讨

在急倾斜构造部位大力使用硬合金回转钻进时,常常会产生弯曲度很大的走向偏斜情况。这是因为不同岩层的阻力差异使钻头受到一种平行于岩层走向的偏斜力,迫使钻头向侧方研磨井壁;在不同井径变换部位所产生的偏斜效果是不同的。这样造成钻孔沿地层走向发生有规律的定向偏斜。     

Intensity attenuation based on earthquake fault-rupture model

Based on the statistical outcomes relevant to elliptical isoseisms given in ref. [1], the average focal depth and rupture length of fault for earthquakes with different magnitudes or epicentral intensities occurring in East and West China are discussed. A set of intensity attenuation functions appropriated to point source (regarding focal distance as the distance parameter in the attenuation law) and the line source (regarding the shortest distance from the site to rupture line or the average distance from the site to both ends of the rupture line as the distance parameter) are proposed.     

Isostatic status in North China (1) Method and local compensation

Following Airy and Pratt principles, five kinds of local-compensation models are analysed and a rapid 3-D gravity formula is utilized to calculate isostatic anomalies for 66 models with different parameters. It is noted that isostatic gravity maps appear nearly identical in their main patterns and features. The optimum compensation model in North China is one of modified Airy models in which the different density distribution in the surface, upper crust and lower crust is taken into account and the standard crustal thickness is about 50km. The position of the complete compensation interface is located in the upper mantle. The North China platform as a whole is under sub-isostatic equilibrium status with an isostatic anomaly of about 18·10⁻⁵ m/s² on an average. The distribution of isostatic gravity anomaly shows an obvious blockwise pattern. Most positive anomaly areas occur over the eastern part, the Jiao-Liao Block, Mt. Yan block and northern margin of the Hebei-Shandong block, whereas a negative area occurs in the Shanxi graben. The comparison of models indicates that the Moho discontinuity is not suitable to be taken as a compensation interface, and the compensation effects in Airy model are better than that in Pratt model, which is consistent with the feature of dominant layered structure and less lateral inhomogeneity in crust. Some results about composite compensation, the basic characteristics of isostatic anomaly and deep stucture will be published later in the second part of this paper. Wang Bowen took part in some work in this paper.     

山东招掖金矿带稀土元素地球化学特征初步研究

本文提出了解决本区某些地质问题的新信息。认为不同地质体具有大体相似的稀土元素配分模型,成岩成矿关系密切,具有继承性演化特点。各类花岗质岩石由胶东群变质岩经混合岩化作用形成。成矿热液富含[CO_3]~(2-)或[HCO_3]~-,金在黄铁矿和石英中富集,与∑REE、LREE的含量及∑Ce/∑Y、Ce/Yb、La/Yb比值呈正相关。上述参数可用作该类金矿床矿化富集规模和强度的评价标志。