基于投影变换的线阵旋转扫描相机标定方法

针对线阵旋转扫描相机标定数据难以获取及模型解算不稳定的问题,提出了一种基于投影变换的线阵旋转扫描相机标定方法。首先构建了一种新的线阵旋转扫描相机成像模型,该模型可以根据相机旋转平台参数、线阵旋转扫描相机成像平面与其切平面的位置关系将旋转扫描图像投影为框幅式图像;然后根据构建出的成像模型,采用直接线性变换法和非线性优化方法进行相机标定和参数优化。试验结果表明,此方法简单易行,具有较高的精度。     

海斗深渊区十字放炮与POBS精确位置校正

TS03航次创新性地投放了 6台被动源海底地震仪(POBS)到马里亚纳海沟南部"海斗深渊区",实施了万米级水深的天然地震观测,通过十字放炮获得POBS的精确坐底位置是后续研究工作中至关重要的一环.本文首先对POBS的SEG-Y数据进行裁截误差修复,然后采用直达水波走时反演的方法得到这6个POBS的精确坐底位置,并进行精...     

CCD Photometry and Long-Term Optical Variability of 3C 345

This paper presents evidence for long-term optical variability and colour behaviour of the blazar 3C 345 (1641+399, z=0.595). Our results show that the amplitude of the optical variations of 3C 345 has been only about 3 magnitudes from its photometric history; existent significant correlation between brightness and colours is found for 3C 345. Our recent CCD photometry of 3C 345 in May 1996 and May 1997 showed that they are in good agreement with our prediction of the optical variability period of about 10 years (see Zhang et al., 1998; Webb et al., 1988). This revised version was published online in July 2006 with corrections to the Cover Date.     

大气降水对昆明周围地震活动的调制

本文对比分析了昆明周围地区20余年来的大气降水记录和地震资料,指出旱涝变异确实与地震活动存在着一定的统计联系。其中尤以震前一年洪涝的作用较为突出。在此基础上,提出了一个可预测本区中强地震发生的经验性方法。     

使用价值分析优化方法在功能-技术矩阵求解中的应用

功能-技术矩阵,经众多工作者的努力研究,已渐趋成熟与实用。但如何利用功能-技术矩阵构造在广义现代设计领域中适用的科学模式,解决多学科设计方案的组成与评价问题,还存在薄弱环节。本文利用\     

基于北斗的车辆管理系统关键技术应用研究

基于北斗系统的导航和通信功能,并利用嵌入式地理信息技术、SOPC嵌入式技术、计算机接口通讯控制技术和数据库技术构建一个高效、稳定的车辆管理系统。通过对该系统中各项关键技术的深入研究,实现了车辆终端自主导航、车辆信息管理、车辆远程控制和路线监管等车辆管理功能。研究表明,本文关键技术可以推广到多项基于北斗系统的应用中。     

Study on cut-off low-pressure systems with floods over Northeast Asia

Summary The cut-off lows (COLs) during the period from June to August 1998 leading to the record flood in Northeast Asia, especially in Northeast China, has been investigated in this paper. The results are as follows: the blocking highs benefited significantly the formation and maintenance of COLs over Northeast China; an obvious frontogenesis zone existed in Northeast China and it implies that baroclinity played an important role in the initiation of COLs, especially in middle and upper troposphere; the maxima of the potential vorticity anomaly were located in the upper troposphere, then extended downwards to the middle and the lower troposphere. The pronounced interaction between systems in upper-middle and low troposphere can be revealed; the moisture supply was from South China, and even from East China Sea and South China Sea. The strong southerly current transported very rich moisture to Northeast China. The maximum of the convergence of moisture flux was below 850 hPa. Obvious interaction between the middle and lower latitude systems was found in the study. Also, the summer monsoon showed significant impacts on the sustained heavy rainfalls related with the COLs over Northeast China; the upward motion could be caused by the lifting of the large scale dynamic forcing and there was no obvious releasing of latent heating in the upper-middle troposphere. The cold dome in the COLs was quite different both from the warm core in tropical cyclone and from the weaker warm core in Meiyu (Baiu) front low. The calculation of vorticity budget shows that both the horizontal advection term and horizontal divergence term contributed importantly to the maintenance and the strengthening of positive relative vorticity. Finally, the complex dynamical characteristics regarding the COLs are discussed and further investigation is proposed.     

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论煤层的加积方式

煤层成因是煤地质学的核心。煤层是一种沉积地层,它遵循沉积学、地层学、岩石学以及矿床学的基本规律,也有其特殊性,其成因并不同于煤的成因。传统煤地质学的核心观点是煤层由泥炭沼泽演化而成,其本质就是成煤物质的垂向加积。通过对煤层垂向和侧向加积的分析对比以及大面积稳定展布的厚煤层低自然伽马多峰现象、层理与条带结构等沉积特征的研究,认为成煤物质是机械沉积的,煤层像大多数沉积岩层一样是侧向加积形成的。对于厚煤层而言,多期侧向加积产生了次生垂向加积,其形成过程不是一个简单的、连续的、线性的垂向累加过程,而是一个复杂的、不连续的、非线性的侧向叠合过程,成煤物质是不连续的、多期多源的,厚煤层中普遍存在的夹矸便是其不连续的证据,同时厚煤层是穿时的。煤层侧向加积与较深水或海相沉积共生,是一个有机连续的整体,符合瓦尔特相律和古生态学原理,符合煤层厚度、形态多变及下伏地层沉积体系多种多样,也符合成煤物质超巨量工业富集、含煤地层灰色灰黑色、煤矿床质量优良的事实。     

地磁干扰噪声的实验观测

为探查1988年3月前后在北京地磁台附近出现的较明显的地磁干扰噪声,我们在苏家坨—卧龙岗一带布设了8个测点,开展了专门的地磁干扰噪声实验观测。结果表明,该地磁干扰噪声主要是来自香山一带的电磁干扰,其次是北京市的地铁干扰。此地磁干扰噪声出现于每天06~h—23~h(北京时),其主要频谱成分在短周期(T=2—4 m)部分。另外本文的观测研究方法对于监测地磁台站(测点)的环境状况,改正受污染的地磁资料等方面具有实际应用价值。