从陆地卫星数据资料计算天然辐射值

一般在分析陆地卫星的影像数据时,是利用记录在计算机兼容磁带上的每个象元的数字来实现的,虽然,对于单一象元来说,这一方法是令人满意的;但是,如果在分析或使用多象元来作镶嵌或多次重叠使用时,则这一方法可能产生错误的结果。应该将每个象元值转换成它们相应的具有等效物理量纲的数值（即具有物理意义的数字）。例如（1）辐射强度,即在卫星轨道上测到的辐射能量,量纲为每（立体）弧度,每平方厘米的毫瓦数值(mWcm^-2)或（2）反射率。这些数值的变化取决于:依据每颗卫星在一定的时间、太阳高度角、大气状态、地形走向和坡度、以及地面覆盖类型等,对多波段扫描仪的核准。大气的核准必不可少,但是,已超出本文的目的和范围。对于陆地卫星1、2和3号的目前五个波段是在忽略大气校正的情况下,用给定的方程计算辐射强度值和反射率的。本文的一个例子中,可以看出不同的卫星计算出的辐射强度和反射率有很大的不同。在分析陆地卫星资料时,把陆地卫星数据表达为天然辐射值,将减少错误。     

立窑水泥熟料显微结构特征

以陕西某水泥厂立窑熟料为研究对象,利用偏光显微镜对水泥正常熟料、过烧和欠烧熟料进行了显微结构分析,揭示了水泥熟料显微结构与烧结过程中室内温度、通风、氧分布等烧结工艺的关系。正常熟料尽管符合出厂条件,但由于烧结工艺实施不合理,使得熟料显微结构欠缺,导致熟料水化性能和抗压强度降低。研究结果表明,正常熟料、过烧和欠烧熟料的判定与C2S的干涉色高低有直接关系。研究结果可用于各水泥厂熟料质量检测和烧结工艺制定。     

地震的等效体力辅导教材

正如Burridge和Knopoff（1964）所著经典论文的“引言”中所指出的，这篇论文在震源理论的发展中起了关键作用。因为数学的发展超越了一些地震学家或并不积极进行理论研究的地震学学生的知识水平，我将讨论一些基本的结果，这些结果将会有助于理解该篇论文，且有助于将其置于更广阔的前景之中。     

Polar Coronal Holes During Solar Cycles 22 and 23

Data from the Solar Wind Ion Composition Spectrometer (SWICS) on Ulysses and synoptic maps from Kitt Peak are used to analyze the polar coronal holes of solar activity cycles 22 and 23 (from 1990 to end of 2003). In the beginning of the declining phase of solar cycles 22 and 23, the north polar coronal holes (PCHs) appear about one year earlier than the ones in the south polar region. The solar wind velocity and the solar wind ionic charge composition exhibit a characteristic dependence on the solar wind source position within a PCH. From the center toward the boundary of a young PCH, the solar wind velocity decreases, coinciding with a shift of the ionic charge composition toward higher charge states. However, for an old PCH, the ionic charge composition does not show any obvious change, although the latitude evolution of the velocity is similar to that of a young PCH.     

OPTIMIZATION OF A CHROMATOGRAPHIC ANALYSIS IN REVERSED PHASE LIQUID CHROMATOGRAPHY

The automatic procedures for optimizing the composition of a binary mobile phase in reversed phaseliquid chromatography have been intensively studied for the past ten years.The performance of theseprocedures,based on either the black box approach or on other methods such as the experimentaldesign,are very often limited by the large number of time-consuming experimental runs that arenecessary for the determination of the analysis conditions to be optimized.The proposed method reduces this number of experiments:two experiments,run under linearvariation of the composition of the binary mobile phase(the linear gradient elution mode),make itpossible to determine the mobile phase composition corresponding to the maximum resolution betweenpeaks,the final analysis being assumed to be carried out under isocratic conditions.The method requires two steps:the determination of the retention characteristics for each solute,which depend upon the composition of the mobile phase;the selection of the optimum composition ofthe isocratic mobile phase,by using a criterion such as the maximum resolution normalized by the squareroot of the plate number,for the least separated pair of adjacent peaks.The interest,performance and limits of use of such an optimization procedure are discussed by meansof the chromatographic analysis of different complex mixtures.     

地理问题和分析方法

最近几十年来,人文地理学在技术手段,特别是在数据的收集、表述和分析上取得了长足进展。然而有一种危险,就是过多注重于手段,结果在研究过程中喧宾夺主。要避免这种情况,就得保证手段的发展与解决实际问题的研究过程密切结合。这里,我只着重谈一下几个问题,以及解决这些问题能够而且应当利用的一些手段。