气象部门事业结构调整对策分析

党的十五大报告明确指出 ,要改造和提高传统产业 ,发展新兴产业和高技术产业 ,推进国民经济信息化 ,信息产业化 ,产业信息化 ,将成为国民经济的主要特征和发展方向。2 1世纪 ,将进入知识经济时代 ,气象工作能否成为一种产业———气象信息产业 ,就是本文要探讨的主要问题。1　气象工作有望成为气象信息产业作为知识经济的重要成员　　气象工作按其行业特点 ,应属于第三产业———服务业范畴。而气象服务主要是技术和信息服务 ,理应定位于信息产业 ,不论是第三产业 ,还是第四产业 ,气象工作都有自己的一席之地 ,有广阔的发展空间。关键是如何…     

用热温度给恒星论资排辈

用热温度给恒星论资排辈○陈华在国家自然科学基金委员会和母校北京大学地球物理系天体物理专业的支持下,我于年初回国短期工作,在此期间深深感到祖国的天文事业与其他事业一样蒸蒸日上,不仅专业工作者,而且公众对天文的热情也很高,我特意将我的学术报告中的一个,写...     

一种面向对象的全球多分辨率纹理数据的预处理方法的研究

建立具有多分辨率、海量数据的大规模虚拟地形场景越来越受到人们的关注,海量纹理数据的管理与生成算法是三维地景仿真的关键技术之一。本文在金字塔塔模型的基础上,运用面向对象思想,设计了多分辨率纹理数据的生成方案,对其流程进行了具体实现,对一些相关技术进行了讨论。通过试验表明,采用本文提出的方法,可以灵活地对全球影像数据进行管理和使用,对全球三维可视化具有一定作用。     

二维地理信息表达在三维空间中的应用分析研究

地理信息表达从二维纸质地图到电子地图再到三维可视化地理环境的飞跃,是地图学史上的一次革命。三维空间认知理论,三维符号体系设计及三维符号变量理论的逐渐完善和发展对三维环境下地理空间信息的表达起到了积极的作用,本文论述了二维地图符号与三维空间信息表达的关系,描述了二维地理信息在三维空间中叠加表示的意义,并分析了二维地图符号表达的优劣性。     

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高温高压合成钻石晶体表面微形貌观察及其成因探讨

我国作为世界上最大的合成钻石生产国,其产量占据世界总产量的90%以上,其中以高温高压法(HPHT)合成钻石为主。国内外学者对于HPHT合成钻石物性的测试方法和性质分析较为完备,但是对HPHT合成钻石生长完成后的酸洗过程以及酸洗后留下的内外部微形貌亟待研究。本文采用激光共聚焦显微镜和超景深三维显微镜对118粒产自我国的HPHT合成钻石进行内外部特征观察,并配合激光拉曼光谱仪对这些微细结构内的包裹残余进行定性分析。发现了三类特征的结构类型:成一定夹角的阶梯型生长结构,揭示了HPHT合成钻石聚型晶的结晶学特质;近平行线状划痕,反映了生长腔体内钻石晶粒间的接触关系;通过独特的"绳捆纹"结构进行观察和分析,认为这一结构反映了HPHT合成钻石的生长速率。这些钻石表面的微形貌反映了HPHT合成钻石梯度高温和持续高压的生长条件和环境,对于HPHT合成钻石的鉴别具有指导意义。     

Long-term marine litter monitoring in the remote Great Australian Bight, South Australia

The Anxious Bay beach litter clearance is the longest running annual survey of ocean-based litter in Australia. It's remoteness from centres of human population and location (with respect to prevailing winds and currents) make it an ideal place for monitoring ocean or ship-based litter in Australia's southern oceans and particularly, the Great Australian Bight. Over the 1991-1999 period, a large but gradual decline in the amount of beach washed litter was recorded (with minor peaks recorded during the 1992 and 1994 surveys). Beach washed litter decreased by approximately 86%, from 344 kg recorded in 1991 (13.2 kg/km) to 49 kg in 1999 (i.e. 1.9 kg/km), reaching a maximum of 390 kg in 1992 (or 15 kg/km of beach). However, a sharp increase in litter was recorded in 2000 (i.e. 252 kg or 9.7 kg/km). This increase in litter yield in 2000 is probably due to stronger than average onshore surface flow (or Ekman Transport) in the western Eyre Peninsula and Bight region. Prior to the survey in 2000, the results appeared to indicate that ocean litter on Anxious Bay beach was beginning to level out at around 50-70 kg/year (i.e. 2-3 kg/km). As the beach surveys involve the assumption that the beach is completely cleared of litter, this may represent a baseline level for ocean-based litter in the region. The yields and type of litter collected from the annual survey indicates that the majority of litter washed ashore originates from commercial fishing activities within the Great Australian Bight. Most of the fishing-related litter was directly sourced to the Southern Rock Lobster Fishery (i.e. bait buckets, baskets, pots), the Great Australian Bight Trawl Fishery (i.e. codends, trawl nets) and the Southern Shark Fishery (i.e. monofilament gillnets and longlines). Between 1994 and 1999, large reductions were observed in the amount of bait straps (77% reduction), lobster bait baskets/buckets (86% reduction), nets/ropes (62% reduction) and floats/buoys (83% reduction). Significantly, fishing-related litter in the Bight has reduced at a slower rate than domestic litter. While the level of glass and soft plastics on the beach have both reduced by almost 93% (i.e. 103-7 kg and 119-8 kg, respectively), the level of hard plastics, has diminished at a slower rate, with reductions of only 75% (i.e. 122-30 kg). Some fisheries (i.e. rock lobster, Southern Shark Fishery) have shown marked reductions in fishing-related litter. This is probably due, to some extent, to significant reductions in fishing effort in the region, although this requires further investigation. The information from the Anxious Bay beach litter survey is crucial in monitoring trends in ocean litter in Australia's southern oceans and compliance with international litter regulations. While fishing-related litter remains the major source of ship-based or ocean litter in Australia's southern oceans, the continued reduction in ship-based litter since 1991 supports increasing compliance to MARPOL (Annex V) by commercial fisheries and shipping in the Great Australian Bight. While Australia participates in marine debris monitoring programs in the Antarctic (under CCAMLR), there is currently no national program or management framework to assess, manage and monitor ocean-based litter along Australia's coasts, and monitor compliance with MARPOL. Apart from the commitments under CCAMLR for Antarctic (and sub-Antarctic) marine environments, there are no other regional programs, guidelines or monitoring protocols or to assess and manage ocean litter in the Southern Ocean.     

堆叠冲断地体变质岩的P—T—t轨迹二维模拟

对瞬时就位变质岩的一维P-T轨迹,前人开展了广泛的研究。不过,逆冲作用的二维性及有限时间对于冲断地体的热演化却是很重要的(Shi和Wang,1987)。本文研究中我们把研究对象扩展到堆叠冲断地体,并且考虑了磨擦生热作用。堆叠冲断地体的等地温线明显与冲断动动学有关(包括冲断速度、冲断时间间隔、断层几何及冲断事件序列)。对于堆叠下冲断层系,当冷的岩板下冲到热的上盘之下时,将会出现温度-深度剖面逆转,当然,它并不象一维锯齿状剖面那样简单。较低的下冲速率与较长的冲断过程有利于热松弛,从而导致温度-深度剖面逆转的减退以及上盘温度的降低。对于多个薄岩片的堆叠,每一岩片的热松弛时间比简单的二单元冲断模式要短,但是在冲断速度相     

QuickBird遥感数据在土地整理工作中的应用

在制作QuickBird数字影像地图的基础上，参照土地整理规划图与前期影像，提取井、路、渠等土地整理相关信息，并与土 地整理规划相比较，实现了对土地整理规划执行情况、土地整理项目进展情况和土地整理项目规划区内土地利用类型变化情况的动 态监测。