秋冬季节珠三角典型区域气溶胶浓度垂直分布的激光雷达反演

气溶胶与全球热辐射平衡、水循环、人类健康密不可分,其观测精度直接影响天气预测、气候建模以及对人类健康影响评估的精度,激光雷达能监测气溶胶的垂直分布,对污染气溶胶的扩散趋势、污染源反演、气候预测等均有重要意义。本文基于激光在大气中的辐射传输过程,根据米散射激光雷达的工作原理,使用雷达的多个系统参数计算雷达常数,建立激光雷达气溶胶质量浓度反演模型,从地面向上在晴空条件下进行了珠三角地区典型区域的秋冬季节气溶胶垂直观测的实验,计算气溶胶质量浓度的垂直廓线,反演气溶胶的垂直分布情况。验证与分析结果表明:(1)激光雷达反演结果显示,白天的反演结果中噪声大大减少,表明反演算法能够有效减弱太阳光的影响。(2)相比于传统方法,使用雷达常数而非边界值的反演结果波动较小,更符合实际,能够有效避免高空噪声的影响。(3)高层大气在晴朗静稳天气状况下较为干净,气溶胶基本分布在低空区域,质量浓度随高度基本呈负指数分布。     

Laboratory examination of linearity in rainfall–runoff relationships

ABSTRACT

Certain rainfall–runoff models, e.g. the unit hydrograph, assume linear relationships between the variables. These are proportionality of runoff discharges to (net) rainfall depth and linear summations of discharges resulting from (net) rainfalls during different time intervals or over different sectors of a watershed. This study examines the validity of these assumptions by use of an extensive two-dimensional laboratory experimentation. The results indicate that proportionality would be found under high rainfall intensity through a long duration. Spatial summations would more likely yield correct discharges in cases where rainfall duration is equal to, or is longer than, the time of concentration. Temporal summations may yield correct discharges when rainfall duration is longer than one half of the time of concentration. Here, the time of concentration is determined at the beginning of gradual approach of the discharge towards the equilibrium state.     

Application of soft-computing techniques in forecasting sediment load and concentration

ABSTRACT

This paper investigates conventional and soft-computing methods for the estimation of suspended sediment concentration (SSC) and load (SSL) in rivers. Frequently used methods of sediment rate curve (SRC) and multi-nonlinear regression, and soft-computing methods of multi-layer perceptron, multi-linear regression and adaptive neuro-fuzzy inference system are implemented using various hydrological and hydraulic parameters for the Little Kickapoo Creek Watershed, Illinois, USA. All methods performed equally well in the estimation of SSL, without any noticeable outperformance from any from the methods. However, the application of soft-computing methods decreased SSC estimation errors considerably as compared to the results of SRC. The results are significant in the way they reconcile traditionally used hydrological parameters into the soft-computing methods. Overall, soft-computing methods are recommended for the estimation of SSC in rivers because of their reasonably better performance and ease of implementation.     

动态大地测量反演理论及其苦干应用

本文从固体力学基本方程出发，提出了动态大地测量反问题。运用有限元法和正则化方法建立了动态大地测量反演的基本理论，研究了动态大地测量反问题的解和性质，提出了动态大地测量反演的正则化方法。最后给出了利用动态大地测量数据反演岩石弹性模量、区域边界力和断层滑动量的一般方法。     

北京地区一次尘暴气溶胶的化学组成及其来源

讨论了1990年4月25日北京地区出现的一次强尘暴过程的气溶胶特征，探讨了尘暴的来源，从对形成尘暴的气象背景以及尘暴气溶胶中元素资料和稀土元素分布模式的分析，认为该次尘暴气溶胶主要是由形成大风地区及其途经地区的尘土微粒混合组成的。     

大气中CO2浓度的全球监测现状

较系统地介绍了大气中ＣＯ＿２浓度（主要是ＣＯ＿２大气背景浓度）的全球监测进展现状。重点阐述了ＣＯ＿２浓度的全球监测网、监测方法、ＣＯ＿２同位素监测、监测质量控制以及ＣＯ＿２监测资料管理等问题的进展状况，分析讨论了当前ＣＯ＿２浓度全球监测中存在的问题和发展前景。     

PRELIMINARY STUDY OF VARIATION OF SO_2 AND AEROSOL PARTICLE BACKGROUND CONCENTRATIONS IN THE EASTERN CHINA

The average concentrations of sulphur dioxide,sulfate aerosol and TSP were about 8—10 ppb,15.08 μg m~(-3),and241.40 μg m~(-3) respectively,which were measured at the Lin'an regional background station during August—November,1991.The higher concentrations of SO_2 and SO_4~(2-) maybe acidify the rainfall.It has a great influence uponthe human health and ecosystem.The simulated results indicate that the distributions of SO_2 and SO_4~(2-) were deter-mined by local emission sources.Average aerosol particle number density was 2.0×10~4 cm~(-3).It shows that social devel-opment and human activities strongly affect the atmospheric background level.     

永春桃东温泉地震预报效果分析

1986年以来台湾省花莲、菲律宾(?)、福建省南日岛海域及蓬壶发生过几次地震,发震前桃东温泉井的水量、水氡含量均有明显的规律性变化,可作为短期地震预报的重要信息。笔者认为其变因与温泉所处的地质构造及地貌环境密切相关。     

中国西部岩浆岩型铜镍矿床的元素组合特征及伴生金的赋存状态研究

我国西部岩浆岩型铜镍矿床伴生金与主金属元素组合,Au—Cu组合具有同步富集特征,而Au—Ni组合为不相关;伴生金与微量元素组合,Au—Pt、Au—Pd、Au—Se、Au—Te呈正相关Au—Co、Au—Os、Au—Ru、Au—Ir、Au—Rh为不相关的组合特征.该类型铜镍矿床伴生金以矿物态赋存为主,分散金较少,主要载体为黄铜矿及其它硫化物.