基于VBA的断面图绘制程序的实现

断面测量作为城市测量工作中的重要组成部分,其在市政设计及施工中起着重要作用。断面图作为断面测量工作提交给客户的重要成果资料,占有较大比重。断面图的绘制一般都有业主单位的特殊要求,绘制过程较为复杂,工作量较大。本文从实际工作出发,分析断面图绘制中可以提高效率的部分工作,并设计和编写程序以提高工作效率。     

古亚洲构造域侵入岩时——空演化框架

长期以来,许多著名学者提出众多模型,讨论古亚洲构造域的构造演化和造山(带)结构样式。但是,认识上的分歧很大,特别是关于主洋盆的空间位置和闭合时间。本文主要基于中国侵入岩大地构造编图(1∶250万)和研究这个侧面,参与讨论。1侵入(岩)弧,碰撞和后造山岩石组合,随时间由西向东变新,同时,主构造带走向从近东西向转为近南北向,暗示古亚洲洋的闭合最终转化为太平洋构造域。2位于主洋盆北侧的是宽阔的西伯利亚克拉通南缘的沟——弧——盆系统;位于南侧的西面为南天山被动陆缘,中部为塔里木克拉通北缘的窄的沟——弧——盆系统,东面为华北克拉通北缘的活动陆缘。3主体侵入(岩)弧的内部分散地分布着从Pt3开始的残留弧和残留oφ,被看做是主体弧的基底。4传统上认为的构造相对稳定的"地块",本文基于它们的侵入(岩)组合归为残留弧,认为不是构造上相对稳定的性质,并未采用"地块"的术语,而把它们看作洋陆转换过程中早期残余岛弧处理。5提出主洋盆的识别有三个标志,(a)洋闭合最晚,(b)或为双向俯冲(当两侧均为活动大陆边缘时),或单向俯冲(当一侧为被动陆缘,另一侧为活动陆缘时),(c)长寿命的洋以及洋闭合带常常发育地中海式残余洋发育的陆——陆碰撞早阶段。6该构造域主要发育Pt3——T的侵入(岩)弧和oφ,支持S¨engor等关于大量新生陆壳的推测,亦与大量花岗岩类为εNd(t)"+"值符合。新生陆壳的形成又暗示,长时间的洋俯冲必导致地幔的冷却,以及大量榴辉岩进入地幔,最终导致高密度的地幔下降流形成,必导致洋的闭合与随后的陆——陆碰撞,形成最初的东亚大陆。     

降雨量等值线图的自动绘制方法

针对当前等值线自动绘制方法中存在的不足,该文以四川区域降雨量为例,分析降雨等值线的特点,依据计算机自动化等值线绘制的基本原则,给出了降雨量等值线的网格区域插值、等值线追踪、等值线平滑和等值线标注整个自动绘制流程的算法设计与具体实现。实验证明该方法易行、准确,可以拓展到更多的等值线绘制领域。     

基于ArcGIS的大比例尺矢量电子地图制图研究

以基于ArcGIS的电子地图制图为研究对象,探讨了电子地图制图的技术流程和方法,详细阐述了使用Maplex引擎对标注进行处理的相关方法,从而创建高质量的动态标注,优化地图标注的数量和质量,为地理信息公共服务平台在线地图展示、浏览和标注提供了数据资源。     

基于智能定位手机的影像信息内外业一体化核查系统

在地理国情普查和未来将持续开展的地理国情监测工作中,其主要作业方式是通过多源遥感获取地类信息。由于自动解译和人工解译准确率较低,外业调查和核实都是必不可少的工作。传统的制图调绘核实方法存在人工定位困难、记录慢和单人识别不可靠等问题。采用最新的平板电脑进行外业调绘存在强光下无法显示、笔触操作不便和电池续航时间短等缺点。本系统以GPS智能手机作为终端,通过网络传输将遥感外业调查像片传回内业数据处理中心,作业员可以根据外业作业人员传回的定位像片进行地类赋值或修改以及检查等工作,实现无缝集成的内外业一体化。     

极地海区等距离正圆柱投影平面上等角航线的展绘方法

墨卡托投影由于其纬度渐长的特性导致在极地海区投影存在严重的长度变形,无法在南北纬80°以外高纬度海区航海图中较好地应用。将长度变形程度明显低于墨卡托投影的等距离正圆柱投影作为极地海区的海图投影,研究了该投影平面中等角航线在极地海区的展绘方法。建立了等距离正圆柱投影平面上等角航线方程并对其曲率进行了分析,推导了绘制一般曲线形态的"以直代曲"公式;最后提出了一种可满足给定精度要求的等角航线展绘算法。实验结果表明:该算法简单易行,可在海图编绘规范规定的误差范围内,实现等角航线的精确展绘。     

青藏块体及周缘潜在震源与强震关系研究

利用1993－1999、1999－2001年青藏块体东北以及1991－2000年中国大陆GPS水平运动年速率资料，基于单一力源模型，反演获得了青藏块体及其周缘地区2000－2001年10次地震的震前资料反映的潜在震源参数，所得力源中心位置距实际震中的距离相对较小，其中2000年景泰5．9、2001年宁蒗5．8、昆仑8．1及格尔木3次5．7、5．8级地震均在50km左右；2000年兴海6．6、2001年年施甸5．9、永胜6．0级地震不到100km；2001年雅江6．0级地震最远（121km）。此外，1999－2001年青藏块体东北缘地区的反演结果表明，沿东昆仑构造带的昆仑山口－达日及库玛断裂向东至甘东南、甘青交界区域，可能仍存在潜在震源。     

SOFTWARE REVIEWS

Software Reviews are in this Article CCS Designer Version 3.0. CoStat Version 3.03; CoPlot Version 1.03, and CoDraw Version 1.03. LASERCAD Version 5.0. 1988. SPSS/PC + Studentware. 1988. SURVEY SYSTEM 1.1C , Version 3.0. THEMAPS Version 1.0.     

Phytoplankton-zooplankton coupling in the outer continental shelf and slope waters of the Mid-Atlantic Bight,June 1979

Measurements of phytoplankton distribution and production, and zooplankton abundance and biomass were made during the summer of 1979 along several shelf-slope transects in the Mid-Atlantic Bight. At the shelf-break, macrozooplankton (>200 μm) grazing was estimated to be sufficient to remove a substantial proportion of daily phytoplankton production. In contrast, on the shelf and in slope waters, where ciliates were abundant, estimates of macrozooplankton grazing indicated a consumption rate less than 15% of the daily primary production. Ciliate grazing, even at non-maximum rates, potentially could have consumed the entire daily primary production in all areas sampled. The findings indicate that the nature of the heterotrophic community is spatially variable in offshore waters even during summer conditions and could influence not only trophodynamic pathways but perhaps nutrient regeneration and recycling. This would be an important consideration in evaluating the fate of particle-bound chemcial species in the water column since fecal pellet producing zooplankton would affect rates of removal and sedimentation in a different manner than ciliates which produce non-compacted digestive debris.     

Geometry and growth of sill complexes: insights using 3D seismic from the North Rockall Trough

Doleritic sill complexes, which are an important component of volcanic continental margins, can be imaged using 3D seismic reflection data. This allows unprecedented access to the complete 3D geometry of the bodies and an opportunity to test classic sill emplacement models. The doleritic sills associated with basaltic volcanism in the North Rockall Trough occur in two forms. Radially symmetrical sill complexes consist of a saucer-like inner sill at the base with an arcuate inclined sheet connecting it to a gently inclined, commonly ragged, outer rim. Bilaterally symmetrical sill complexes are sourced by magma diverted from a magma conduit feeding an overlying volcano. With an elongate, concave upwards, trough-like geometry bilaterally symmetrical sills climb away from the magma source from which they originate. Both sill complex types can appear as isolated bodies but commonly occur in close proximity and consequently merge, producing hybrid sill complexes. Radial sill complexes consist of a series of radiating primary flow units. With dimensions up to 3 km, each primary flow unit rises from the inner saucer and is fed by primary magma tube. Primary flow units contain secondary flow units with dimensions up to 2 km, each being fed by a secondary magma tube branching from the primary magma tube. Secondary flow units in turn are composed of 100-m scale tertiary flow units. A similar branching hierarchy of flow units can also be seen in bilaterally symmetrical sill complexes, with their internal architecture resembling an enlarged version of a primary flow unit from a radial sill complex. This branching flow pattern, as well as the interaction between flow units of varying orders, provides new insights into the origin of the structures commonly seen within sill complexes and the hybrid sill bodies produced by their merger. The data demonstrate that each radially symmetrical sill complex is independently fed from a source located beneath the centre of the inner saucer, grows by climbing from the centre outwards and that peripheral dyking from the upper surface is a common feature. These features suggest a laccolith emplacement style involving peripheral fracturing and dyking during inner saucer growth and thickening. The branching hierarchy of flow units within bilaterally symmetrical sill complexes is broadly similar to that of primary flow units within a radially symmetrical sill complex, suggesting that the general features of the laccolith emplacement model also apply.Editorial responsibility: J. Stix