基于AutoCAD的海底浅地层剖面成图方法

研究了基于AutoCAD二次开发进行海底浅地层剖面计算机成图的方法,设计了包含数据输入、坐标提取、投影计算及自动加载等功能的VBA程序,实现了海底浅地层剖面的计算机自动成图。     

太阳大气温度极小区的周期性变化初探

从１９７４年起,基特峰天文台几乎每月定期对太阳大气的Ｋ线及其他一些谱线进行观测记录,以往对Ｋ线的研究表明：Ｋ１形成于温度极小区（ＴＭＲ）,Ｋ１到线心的距离以及Ｋ１的强度分别与温度极小区的位置和温度密切相关,对基特峰Ｋ值线轮廓的有关数据以及最近数十年的太阳黑子数进行了研究,发现：全日面Ｋ线轮廓的Ｋ１到线心的距离随时间的变化与太阳黑子数的变化是同步的,而对于日面中心（可视为宁静太阳）的Ｋ线轮廓而言,Ｋ     

200-kg large explosive detonation facing 50-km thick crust beneath west Qinling,northeastern Tibetan plateau

It is difficult to acquire deep seismic reflection profiles on land using the standard oil-industry acquisition parameters. This is especially true over much of Tibetan plateau not only because of severe topography and rapid variation of both velocity and thickness of near-surface layer, but also strong attenuation of seismic wave through the thickest crust of the Earth. Large explosive sources had been successfully detonated in US, but its application in Tibetan plateau rarely has an example of good quality. Presented herein is the data of a 200-kg single shot we recorded in west Qinling, northeastern Tibetan plateau. The shot gather data with phenomenal signal-to-noise ratios illustrate the energy of the PmP phase. Although the observations are only limited to the northeastern Tibetan plateau and thus cannot comprise an exhaustive study, they nevertheless suggest that large explosions may be a useful exploration tool in Tibetan Plateau where standard seismic sources and profiling methods fail to produce adequate data of low crust.     

Spatial history of kauri driving dam placement in the Kauaeranga Valley,Coromandel Peninsula

Understanding past anthropogenic influences on fluvial systems is an integral part of riverine research. In this paper the spatial history of kauri driving dam placement from the 1870s to the 1930s is studied using oral histories, historic documents and GIS in an attempt to assess the accuracy of historical accounts in reference to dam position in the landscape and assess the relationship of dam position to landscape features and characteristics. GIS results supported historical documentation showing that key factors influencing dam placement were location to kauri, geomorphic impediments to transport, slope and distance to deep water for rafting.     

国土资源信息专用标准规则研究

在综述国内外信息技术领域、地理信息领域专用标准进展和列举国土资源信息专用标准构成方式的基础上,对国土资源信息专用标准的制定规则进行研究,确定了国土资源信息专用标准的基础标准构成、专用标准与基础标准的关系、专用标准的一致性要求和一致性测试及专用标准的文档结构,提出了专用标准实施中需解决的问题.     

天山北麓河流纵剖面与基岩侵蚀模型特征分析

本文提取分析天山北麓10条河流的纵剖面,通过函数拟合纵剖面形态特征,同时运用基岩侵蚀力模型来研究河流纵剖面形态的发育演化过程,来揭示河流纵剖面的发育与构造活动之间的内在关系.研究表明:天山北麓河流地貌地形发育阶段处于河流侵蚀作用强烈的前均衡状态时期.塔西河的纵剖面凹曲度最大,向东西两侧河流凹曲度依次降低,乌鲁木齐河与四棵树河凹曲度最小,河流的凹曲度(θ)和河道坡度(Ks)的数值分布规律与所对应构造部位晚更新世以来的抬升速率和地壳缩短速度相一致,排除时间、气候因素和基岩性质影响因素后.发现晚更新世以来天山北麓河流纵剖面形态变化主要受构造抬升作用的影响.     

Soil moisture of different vegetation types on the Loess Plateau

Water stored in deep loess soil is one of the most important resources regulating vegetation growth in the semi-arid area of the Loess Plateau, but planted shrub and forest often disrupt the natural water cycle and in turn influence plant growth. The purpose of this study was to examine the effects of main vegetation types on soil moisture and its inter- annual change. Soil moisture in 0–10 m depth of six vegetation types, i.e., crop, grass, planted shrub of caragana, planted forests of arborvitae, pine and the mixture of pine and arborvitae were measured in 2001, 2005 and 2006. Soil moisture in about 0–3 m of cropland and about 0–2 m of other vegetation types varied inter-annually dependent on annual precipitation, but was stable inter-annually below these depths. In 0–2 m, soil moisture of cropland was significantly greater than those of all other vegetation types, and there were no significant differences among other vegetation types. In 2–10 m, there was no significant moisture difference between cropland and grassland, but the soil moistures under both of them were significantly higher than those of planted shrub and forests. The planted shrub and forests had depleted soil moisture below 2 m to or near permanent wilting point, and there were no significant moisture differences among forest types. The soil moisture of caragana shrub was significantly lower than those of forests, but the absolute difference was very small. The results of this study implicated that the planted shrub and forests had depleted deep soil moisture to the lowest limits to which they could extract and they lived mainly on present year precipitation for transpiration.     

海陆风及沿海风速廓线在风电场风速预报中的应用

为了建立沿海风功率预报系统,本文探讨了中国沿海风电场风速预报问题,并利用数值模式RAMS对海陆风进行了模拟研究.发现海陆风发生时,海风和陆风阶段风速廓线存在较大差异,海风阶段风速的垂直切变明显小于陆风阶段.海陆风发生时,风速会呈现有规律的变化,即海风和陆风分别有两个时段：风速增加时段和风速减少时段.在为沿海风电场提供风速预报时,当模式预报到海陆风发生时,可以利用海陆风的这种特点,使用统计方法对预报出的风速进行有效的订正.并发现即使没有海陆风发生,当风向为海洋吹向陆地时,风速随高度的垂直切变同样小于陆地吹向海洋的时段.利用统计方法根据不同风向时风速廓线的特性,把数值模式计算高度上的预报结果,精确地插值到风机涡轮高度,会很大程度上减少风速预报的误差及风功率预报环节的误差.     

银川断陷盆地地壳结构与构造的地震学证据

通过跨银川断陷盆地,完成了一条长68.9 km的高分辨深地震反射探测剖面,首次获得了银川盆地地壳精细结构、地堑型断陷盆地深部断裂系（黄河断裂、银川断裂、贺兰山东麓断裂）特征及深浅构造关系.结果表明：银川断陷盆地上地壳为双程走时8 s（深度约20 km）反射面以上的区域,上地壳上部地层层位丰富,地层分段连续性较好,上地壳下部地层分层特征不明显,地质构造简单;下地壳(8～13 s)反射能量较弱,反射同相轴不明显;下地壳下部壳幔过渡带（13 s附近）由一组能量较强、持续时间较长（1.5 s）的反射波组组成,厚度约4.5 km.芦花台断裂、银川断裂分别于12～12.5 km、18～19 km深处交汇于贺兰山东麓断裂,贺兰山东麓断裂于28～29 km深处交汇于黄河断裂,黄河断裂为错断Moho面的深大断裂,银川地堑为以黄河断裂为主,其他断裂为辅组合而成的负花状构造.根据贺兰山东麓断裂和银川断裂的相互关系,认为贺兰山东麓断裂对1739年平罗—银川8级地震起主要控制作用.     

Direct time-domain soil profile reconstruction for one-dimensional semi-infinite domains

We discuss the inverse medium problem associated with the reconstruction of the heterogeneous material profile of a semi-infinite (layered) soil medium, directly in the time domain, based on the complete waveform response of the medium to interrogating waves. To tackle the inversion process, we use a partial-differential-equation-constrained optimization approach, supplemented with a time-dependent regularization scheme. We introduce an absorbing boundary to truncate the semi-infinite extent of the physical domain, and propose two schemes to refine the reconstructed profiles: the first is based on iteratively re-positioning the truncation boundary until convergence, and the second is based on optimizing the observation period, so as to exclude records with information beyond the truncation boundary. We present numerical results that attest to the efficacy of the proposed schemes in reconstructing sharp profiles of semi-infinite soil domains using both noise-free and noisy data, while in the presence of absorbing boundaries.