The most primitive lower tetrapod fauna in China

A comprehensive analysis of the fauna indicates that three vertebrate assemblage zones existed in the Upper Permian of China. Among them the Dashankou lower tetrapod fauna consisting mainly of therapsids is the most primitive and abundant one. It is more closely related to Zone II of Russia than to theEodicynodon Assemblage Zone of South Africa. Zone II of Russia in the Late Permian played a role of bridge for the dispersal of tetrapods from North America to South Africa and China at that time     

GT－1型工程导向孔多功能无线探测仪和GD－200型钻机在非开挖铺线技术中的应用

介绍ＧＴ－１型工程导向孔多功能无线探测仪的功能、组成参数和ＧＤ－２００型全液压动力头式钻机的组成、性能、主要参数、主要特点以及两者在非开挖铺设管线技术中的配套试验情况。     

基于GIS技术的公路综合选线方法

首次提出了基于ＧＩＳ技术的公路综合选线方法。应用ＧＩＳ技术的空间分析功能,提取公路选线的影响信息;在此基础上,将公路选线问题层次化,并利用层次分析的方法,实现公路选线多因素的综合分析,达到公路综合选线的目的。     

OUTLIER DETECTION AND RELIABILITY OF ADJUSTMENT MODELS WITH SINGULAR COVARIANCE MATRICES

Up to now,outlier detection and reliability theory are generallybased on the regular Gauss-Markov models,in which the covariance matrix of ob-servations is positively definite.For the adjustment models with singular covari-ance matrix,the statistics for outlier detection are derived by the authors.Thecorresponding reliability theory is developed.And the application of the theory isdemonstrated with a practical example.     

关于南京猿人生存时期的气候环境讨论

根据南京猿人产地（葫芦洞）中的孢粉分析结果推测当时气温明显比现在低,可能相当于一次冰期。该结论与南京猿人共生的哺乳动物化石群的性质是一致的。     

GPS/Pseudolite/INS integration: concept and first tests

This paper discusses the introduction of pseudolites (ground-based GPS-like signal transmitters) into existing integrated GPS/INS systems in order to provide higher availability, integrity, and accuracy in a local area. Even though integrated GPS/INS systems can overcome inherent drawbacks of each component system (line-of-sight requirement for GPS, and INS errors that grow with time), performance is nevertheless degraded under adverse operational circumstances. Some typical examples are when the duration of satellite signal blockage exceeds an INS bridging level, resulting in large accumulated INS errors that cannot be calibrated by GPS. Such a scenario, unfortunately, is a common occurrence for certain kinematic applications. To address such shortcomings, both pseudolite/INS and GPS/pseudolite/INS integration schemes are proposed here. Typically, the former is applicable for indoor positioning where the GPS signal is unavailable for use. The latter would be appropriate for system augmentation when the number and geometry of visible satellites is not sufficient for accurate positioning or attitude determination. In this paper, some technical issues concerned with implementing these two integration schemes are described, including the measurement model, and the appropriate integration filter for INS error estimation and correction through GPS and pseudolite (PL) carrier phase measurements. In addition, the results from the processing of simulated measurements, as well as field experiments, are presented in order to characterize the system performance. As a result, it has been established that the GPS/PL/INS and PL/INS integration schemes would make it possible to ensure centimeter-level positioning accuracy even if the number of GPS signals is insufficient, or completely unavailable. Electronic Publication     

Pseudo-Satellite Applications in Deformation Monitoring

In this article, three general classes of potential pseudolite applications for deformation monitoring are described. The first is GPS augmentation with pseudolite(s), which is suitable for circumstances such as urban canyons, or for monitoring in valleys and deep open-cut mines. The second is indoor applications of pseudolite deformation monitoring systems. Pseudolite arrays can, in principle, completely replace the GPS satellite constellation. This could extend the “satellite-based” deformation monitoring applications into tunnels or underground, where GPS satellite signals cannot be tracked. The last case is an inverted pseudolite-based deformation monitoring system, where a “constellation” of GPS receivers with precisely known “orbits” track a mobile pseudolite. The system consists of an array of GPS receivers, the base reference pseudolite, the mobile pseudolite, and a central processing system. However, in the case of such pseudolite-only or hybrid pseudolite-GPS deformation monitoring systems, some additional issues need to be addressed. These include multipath, atmospheric delay effects, and pseudolite location-dependent biases. To address deformation monitoring applications, some practical procedures to mitigate or eliminate their influence are suggested. Some experiments were carried out using NovAtel GPS receivers and IntegriNautics IN200CXL pseudolite instruments. The experimental results indicate that the accuracy of the height component can indeed be significantly improved – the RMS of the vertical component has been reduced by a factor of 4, to the same level as the horizontal components. Their performance will be demonstrated through case study example. ? 2002 Wiley Periodicals, Inc.     

曹妃甸近岸海域垂向悬沙含量遥感反演

利用遥感技术监测水体悬浮泥沙含量是海洋水色遥感的一个重要研究方向。本文以曹妃甸近岸海域4个剖面35个站点开展的现场光谱测量、同步采集的不同深度悬浮泥沙含量样品数据为基础,采用Landsat-5 TM遥感数据,建立水体表、中、底层悬沙含量遥感反演模型,并研究悬沙垂向上的空间分布规律。结果表明,曹妃甸近岸海域泥沙含量在垂向上有明显的相关性,以Landsat-5 TM影像反射率比值（R_TM3/R_TM2）为因子,构建优化的悬浮泥沙含量遥感反演模型,各层模型平均相对误差都在30%以内,表层和中层的平均绝对误差在6 mg/L以下,均方根误差小于10 mg/L,底层的精度略低于表层和中层。研究结果为进一步研究海洋环境泥沙运移规律、优化水动力作用下泥沙运移模型提供支持。     

砂层应力资料的研究与应用

对砂层应力仪产出的数据进行分析,发现影响数据分析的主要因素包括高频与低频信息中的噪声、观测信号的背景性变化、地震前兆的趋势异常与短期异常等。为识别与消除干扰提取不同频率的信息,采用小波分析方法对信号进行了处理。