数字河流数据的自动综合

本文主要介绍了数据库中水系要素综合中河流的自动综合方法，尤其是对非结构化河网中河流的自动选取作了较为详细的论述，并通过数据库中一幅完整图幅的河流数据对文中介绍的自动综合方法进行了验证。     

全国地面资料自动收集处理系统的运行结构

全国地面资料实现通信传输后,统一预处理软件,在同一平台上建立国家和省一级地面资料收集处理运行系统,不仅可减少不必要的麻烦,简化操作提高工作效率,还可加强上下之间的联系,提高系统整体性和工作质量。     

结合第8届国际探空仪系统比对试验探讨国产气球施放高度

根据阳江探空站高空气象探测用750g气象气球施放的实际高度的现状,结合中国大探中心组织国产GPS探空仪在阳江用国产2000g气象气球比对试验时施放的高度以及广东阳江第8届国际探空仪系统比对期间施放的实际高度,探讨雨天和高空相对湿度较大的气象条件下对国产气象气球施放高度的影响。结果显示,雨天或高空相对湿度较大时,对国产现有的气象气球施放的高度存在较大的影响。研究表明,解决了国产气象气球的球皮防雨、防潮问题,很大程度上解决了国产气象气球施放高度不稳定的难题。     

Last glacial terrestrial vegetation record of leaf wax n-alkanols in the northern South China Sea: Contrast to scenarios from long-chain n-alkanes

Long-chain n-alkanols and n-alkanes in core sediments from the northern South China Sea (SCS) were measured to make a comparison during terrestrial vegetation reconstruction from ~42 ka to ~7 ka. The results showed that terrestrial vegetation record from long-chain n-alkanes matched well with previous studies in nearby cores, showing that more C₄ plants developed during the Last Glacial Maximum (LGM) and C₃ plants dominated in the interglacial period. However, these scenarios were not revealed by terrestrial vegetation reconstruction using long-chain n-alkanols, which showed C₃ plant expansion during the LGM. The discrepancy during the interglacial period could be attributed to the aerobic degradation of functionalized long-chain n-alkanols in the oxygen-rich bottom water, resulting in poor preservation of terrestrial vegetation signals. On the other hand, the different advantages of functionalized n-alkanols and non-functional n-alkanes to record local and distal vegetation signals, respectively, may offer a potential explanation for the contradiction during the LGM when the SCS was characterized by low-oxygen deep water. Nevertheless, large variations on n-alkyl lipid compositions in C₃/C₄ plants could play a part in modulating sedimentary long-chain n-alkanols and n-alkanes toward different vegetation signals, thereby suggesting that caution must be taken in respect to the terrestrial vegetation reconstruction using long-chain n-alkanes and long-chain n-alkanols.     

Study on topographic compensation model of the Okinawa Trough I. Calculation of theoretical isostatic response function

INTRODUCTIONTo study the compensation model of sea topography and isostatic states by using toPOgraphicand gravity data, is an imPOrtant mean for further researching deep structures as elastic structure,stress state of lithosphere, and so on. Since Airy and Pratt proPOsed local isostatic model in the1850' s, greater development on the theoretical study has been attained. Veining Meinesz (1941 )introduced regional compensation mechanism by considering it as floating crust in elastic fie…     

Diurnal variation of nitric oxide emission flux from a mangrove wetland in Zhangjiang River Estuary,China

The diurnal variation of nitric oxide (NO) emission fluxes from a Kandelia obovata and Avicennia marina mangrove wetland were studied in the Zhangjiang River Estuary Mangrove National Nature Reserve using a dynamic chamber-based technique and a chemiluminescent analyzer. Results from field experiments show that NO emission from K. obovata and A. marina sampling sites reached maximal values of 1.07 ng N m⁻² s⁻¹ and 1.23 ng N m⁻² s⁻¹, respectively after the night tide. Meanwhile NO emission maintained at a steady lower level in daytime for both wetland sites. In laboratory experiments, NO emission from the mangrove wetland soil samples treated with simulated tides in the darkness exhibited higher values than those in the light, therefore it seems that tides and darkness could increase NO emission from mangrove wetlands, while intensive light, high temperature, and dryness in the daytime decreased NO emission. Compared with K. obovata soil samples, the diurnal average NO emission rate of the A. marina site was significantly higher, which was closely related to relatively higher diurnal average CO₂ emission rate, soil available nitrogen content and soil net nitrification rate of the A. marina site. Moreover, soil samples of the A. marina site were more responsive to simulated tides and the addition of nitrogen than those of the K. obovata site.     

利用卫星遥感资料估算海面太阳辐照度的初步结果

本文在分析了若干由卫星信息提取地表的太阳辐照度物理模式的基础上,将１９９５年５月２６日的ＮＯＡＡ卫星ＡＶＨＲＲ资料经适当变换后,选用Ｈａｙ和Ｈａｎｓｏｎ模式估算并分析了黄渤海３５°～４０°Ｎ、１２０°～１２５°Ｅ海区的海面太阳辐照度值。文中指出,卫星测量可成为海面太阳辐照度观测的有效手段。建议：１）尽快在国内开展这方面的研究;２）应进行海洋实况测量（最好是卫星过境时同步进行）;３）建立从卫星资料提取我国海区海面辐照度的适用算法。     

海洋沉积物中烃类化合物预处理条件优化及应用

运用分辨率高、稳定性好的ＨＰ６８９０ 毛细管气相色谱仪定性、定量测定海洋沉积物中的正构烷烃和多环芳烃。对沉积物样品的预处理中抽提、蒸发、柱层析、萃取等步骤条件进行优化。优化方法中,正构烷烃系列化合物回收率为６５ ％ ～７６ ％ ,多环芳烃系列化合物为８８ ％ ～９５％ ,标准偏差是２．７％ ～２０．２％ （ｎ＝ ３）