成层介质中交流电测井响应

本文给出了纵向成层、径向不均匀介质中轴对称电磁波的反射阵和透射阵的递推公式．用这些阵可以计算交流电测并响应，包括感应测并和深探测电磁波传播测井（ＤＰＴ）．同时还给出了幅度基函数和斜度基函数，它们分别＂支撑＂起结点上函数的幅度和斜度．     

美国长期天气预报业务的新发展──发布气候展望

从１９９５年元月份起，美国天气局正式发布预见期为一年的业务性气候展望，该文简要地介绍了美国天气局作出这些重大变更的科学依据、预报方法、预报制作与预报准确等方面的情况。     

大型GIS与数字地球的空间数学基础研究

将地图投影概念由传统的曲面到平面的变换扩展为曲面到曲面的变换，并提出一套适合于大型GIS和地球数字产品的实用“地图投影”模型。该模型的视图采用等距离切圆柱投影，度量空间是椭球面几何系统，符合计算机环境下GIS视图与度量空间分离的特性。鉴于全球多分辨率连续可视化，精密可视化量算，三维、多维地球数据统一，标准的空间定位框架和只有在统一的空间系统内，全球资源、生态环境数据才能进行精确的地理分析等4个方面的需要，从地图投影发展到本模型将是方向和技术趋势。     

论地球系统科学与可持续发展战略科学基础（Ⅰ）

地球系统科学是可持续发展战略的科学。它脱胎于气候系统研究，跨越一系一自然与社会科学，将全球变化与区域变化冶为一炉，所涵差的时间数十年至一二百年，在此时间尺度内，所涵盖的对象基本上是大气、海洋与陆地以及介于其间的物质能量交换过程。陆地最重要、最复杂、受人类活动的影响亦最大，目前未知数亦最多。宜先在跨学科的综合工作上多下功夫，积极推动地系统研究。     

Estimation of regionalized compositions: A comparison of three methods

A regionalized composition is a random vector function whose components are positive and sum to a constant at every point of the sampling region. Consequently, the components of a regionalized composition are necessarily spatially correlated. This spatial dependence—induced by the constant sum constraint—is a spurious spatial correlation and may lead to misinterpretations of statistical analyses. Furthermore, the cross-covariance matrices of the regionalized composition are singular, as is the coefficient matrix of the cokriging system of equations. Three methods of performing estimation or prediction of a regionalized composition at unsampled points are discussed: (1) the direct approach of estimating each variable separately; (2) the basis method, which is applicable only when a random function is available that can he regarded as the size of the regionalized composition under study; (3) the logratio approach, using the additive-log-ratio transformation proposed by J. Aitchison, which allows statistical analysis of compositional data. We present a brief theoretical review of these three methods and compare them using compositional data from the Lyons West Oil Field in Kansas (USA). It is shown that, although there are no important numerical differences, the direct approach leads to invalid results, whereas the basis method and the additive-log-ratio approach are comparable.     

Groebner-basis solution of the three-dimensional resection problem (P4P)

The three-dimensional (3-D) resection problem is usually solved by first obtaining the distances connecting the unknown point P{X,Y,Z} to the known points P_i{X_i,Y_i,Z_i}i=1,2,3 through the solution of the three nonlinear Grunert equations and then using the obtained distances to determine the position {X,Y,Z} and the 3-D orientation parameters {,, }. Starting from the work of the German J. A. Grunert (1841), the Grunert equations have been solved in several substitutional steps and the desire as evidenced by several publications has been to reduce these number of steps. Similarly, the 3-D ranging step for position determination which follows the distance determination step involves the solution of three nonlinear ranging (`Bogenschnitt') equations solved in several substitution steps. It is illustrated how the algebraic technique of Groebner basis solves explicitly the nonlinear Grunert distance equations and the nonlinear 3-D ranging (`Bogenschnitt') equations in a single step once the equations have been converted into algebraic (polynomial) form. In particular, the algebraic tool of the Groebner basis provides symbolic solutions to the problem of 3-D resection. The various forward and backward substitution steps inherent in the classical closed-form solutions of the problem are avoided. Similar to the Gauss elimination technique in linear systems of equations, the Groebner basis eliminates several variables in a multivariate system of nonlinear equations in such a manner that the end product normally consists of a univariate polynomial whose roots can be determined by existing programs e.g. by using the roots command in Matlab.Acknowledgments.The first author wishes to acknowledge the support of JSPS (Japan Society of Promotion of Science) for the financial support that enabled the completion of the write-up of the paper at Kyoto University, Japan. The author is further grateful for the warm welcome and the good working atmosphere provided by his hosts Professors S. Takemoto and Y. Fukuda of the Department of Geophysics, Graduate School of Science, Kyoto University, Japan.     

多普勒雷达的速度图像特征及其在一次降雪过程中的应用

该文首先介绍了大面积降水的多普勒天气雷达径向速度PPI图像识别技术, 包括:①冷暖平流与大尺度辐合辐散运动叠加的图像特征; ②由零线的朝向和正负速度面积、径向速度值的大小判断风向风速辐合辐散的图像特征, 然后介绍了利用EVAD技术由雷达基数据定量计算大气平均散度和平均垂直速度的方法, 最后应用图像识别技术和EVAD方法对石家庄2004年冬季的一次大面积降雪过程进行了详细分析, 发现:此次大面积降雪过程有明显的辐合辐散图像特征, 径向速度值小, 辐合辐散弱, 始终存在暖平流。另外, 降雪强度和散度、垂直速度关系密切:辐合层厚度加大, 辐散抬高, 则降雪加强; 辐合、辐散层高度降低, 则降雪减弱。同时, 由EVAD技术定量计算的散度和相同时刻由径向速度图像产品定性分析的辐合、辐散基本一致。     

中国古代地图的数学基础与地理空间维度认知

从几个典型的中国古地图的数学基础出发,结合相关的数学方法,探讨了中国古人在地理空间维度认知方面走过的历程。认为,当中国古代地图发展到以"计里画方"进行地图绘制时,已经实现了3维地理空间的科学认知。这也是"计里画方"的制图方法可以持续1 000多年的理论依据。     

1480型多普勒天气雷达中尺度气旋识别模块设计

借鉴国内外中尺度气旋识别算法的研究成果特别是NSSL(National Severe Storm Laboratory)的中尺度气旋识别算法,结合多普勒天气雷达二次产品软件的特点,提出了改进的中尺度气旋识别算法,以动态链接库的形式,设计完成了中尺度气旋识别模块.对2002年5月27日安徽省北部地区的一次强对流天气过程的雷达资料进行了分析,并与北京敏视达(METSTAR)雷达有限公司Build 10.8软件系统生成的中尺度气旋产品进行了对比分析,结果表明该模块有比较好的识别能力,预警效果较好.     

X-ray binary unified analysis: pulse/RV application to Vela X1: GP Velorum

A procedure for simultaneous analysis of multiple kinds of observations is developed for binaries that contain X-ray pulsars. A wide variety of observation types might be included, although we consider only velocity: pulse and light: velocity: pulse cases at present. The model operates with equipotentials and can accommodate non-synchronous rotation and eccentric orbits. The duration condition imposed by observed X-ray eclipses is incorporated as an embedded constraint, so that only solutions consistent with the eclipse duration are found. Relations needed for the method of differential corrections in least-squares solutions are specified, and we apply the Marquardt scheme for improvement of solution convergence. Parameters of Vela X1: GP Velorum are obtained from seven combinations of pulse and radial velocity data. The estimated masses are thereby put into some perspective, especially for the neutron star. The mass of the supergiant ( m  sin³  i ) now ranges only ±5 per cent from the mean of seven results, although the uncertainty in i makes the actual mass range larger. We discuss the determinacy of certain parameters and their historical consistency. For example, the systemic radial velocity differs among spectroscopic data sets by more than 20 km s⁻¹. We show that, contrary to published assertions, the orbital inclinations of high-mass X-ray binaries are essentially indeterminable by the usual methods, although lower limits to inclination may be meaningful for some examples.