Regularity and estimation of methane emission from marshland in the Sanjiang Plain

ＲＥＧＵＬＡＲＩＴＹＡＮＤＥＳＴＩＭＡＴＩＯＮＯＦＭＥＴＨＡＮＥＥＭＩＳＳＩＯＮＦＲＯＭＭＡＲＳＨＬＡＮＤＩＮＴＨＥＳＡＮＪＩＡＮＧＰＬＡＩＮ①ＣｕｉＢａｏｓｈａｎ（崔保山）ＭａＸｕｅｈｕｉ（马学慧）ＣｈａｎｇｃｈｕｎＩｎｓｔｉｔｕｔｅｏｆＧｅｏｇｒ...     

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。     

Study of red tide prediction model for the Changjiang Estuary

ＩＮＴＲＯＤＵＣＴＩＯＮＡｑｕｉｃｕｌｔｕｒｅａｒｅａｒｅｄｔｉｄｅｓｉｇｎａｌｓｏｃｅａｎｐｏｌｌｕｔｉｏｎａｎｄｄｉｓａｓｔｅｒ.Ａｌｔｈｏｕｇｈｅｎｖｉｒｏｎｍｅｎｔｓｃｉｅｎｔｉｓｔｓｈａｖｅｃｏｎｄｕｃｔｅｄｍａｎｙｉｎ ｄｅｐｔｈｒｅｓｅａｒｃｈｅｓｏｎｔｈｅｃａｕｓｅａｎｄｆｏｒｍａｔｉｏｎｍｅｃｈａｎｉｓｍｏｆｒｅｄｔｉｄｅ ,ｍａｎｙｏｆｉｔｓａｓｐｅｃｔｓａｒｅｓｔｉｌｌｕｎｋｎｏｗｎｂｅｃａｕｓｅｒｅｄｔｉｄｅｉｓａｃｏｍｐｌｅｘｐｈｅｎｏｍｅｎｏｎａｎｄｔｈｅｅｃｏｌｏｇｉｃ…     

Tests and applications of an approach to absorbing reflected waves towards incident boundary

If the upstream boundary conditions are prescribed based on the incident wave only, the time-dependent numerical models cannot effectively simulate the wave field when the physical or spurious reflected waves become significant. This paper describes carefully an approach to specifying the incident wave boundary conditions combined with a set sponge layer to absorb the reflected waves towards the incident boundary. Incorporated into a time-dependent numerical model, whose governing equations are the Boussinesq-type ones, the effectiveness of the approach is studied in detail. The general boundary conditions, describing the down-wave boundary conditions are also generalized to the case of random waves. The numerical model is in detail examined. The test cases include both the normal one-dimensional incident regular or random waves and the two-dimensional oblique incident regular waves. The calculated results show that the present approach is effective on damping the reflected waves towards the incident wave boundary.     

国际南极大地参考框架的构建与进展

回顾了南极大地参考框架发展的历史,总结了由国际南极研究科学委员会(SCAR)组织的历次南极地区大地测量观测活动的成果,并结合2007~2008第四次国际极地年(IPY)对南极大地参考框架的前景进行了展望,其中重点介绍了我国对构建南极大地参考框架的贡献。     

The hydrothermal karstification and its effect on Ordovician carbonate reservoir in Tazhong uplift of Tarim Basin,Northwest China

With a detailed study on petrology, mineralogy and geochemistry of some important Ordovician carbonate well core samples in Tazhong uplift of Tarim Basin, the distinguishing symbols of hydrothermal karstification are first put forward as the phenomena of rock hot depigmentation, hot cataclasm and the appearance of typical hydrothermal minerals such as fluorite, barite, pyrite, quartz and sphalerite. The main homogenization temperatures of primary fluid inclusions in fluorite are from 260 to 310°C, indicating the temperature of hydrothermal fluid. The fluid affected the dissolved rocks and showed typical geochemistry features with low contents of Na and Mg, and high contents of Fe, Mn and Si. The ratio of ³He/⁴He is 0.02R _a, indicating the fluid from the typical continental crust. The hydrothermal fluid karstification pattern may be described as follows: the hot fluid is from the Permian magma, containing dissolving ingredients of CO₂ and H₂S, and shifts along fault, ruptures and unconformity, and dissolves the surrounding carbonates while it flows. The mechanism of hydrothermal karstification is that the mixture of two or more fluids, which have different ion intensity and pH values, becomes a new unsaturated fluid to carbonates. The hydrothermal karstification is an important process to form hypo-dissolved pinholes in Ordovician carbonates of Tazhong uplift of Tarim Basin, and the forming of hydrothermal minerals also has favorable influence on carbonate reservoirs.

     

Heavy-Rain expert-system realized by logical language prolog

This article, on the basis of the expert’s analyses and theories of the forecast of heavy-rain, summarizes a variety of the current instruments and methods of forecast and, according to the train of thought of the high-rank forecasters, distills their experiences in forecasting heavy-rain into an inference-tree of 106 junctures from which 101 rule-bases are derived. The logical calculation is automatically carried out with our introduced and developed PROLOG, one of the intelligent languagas by means of micro-computer. This process adopts the uncertain inferential method based on the theory of fuzzy sets, breaks through the limits of two-value logic and is characteristic of the thinking of human brain.