SYMMETRIC AND ASYMMETRIC MOTIONS IN THE BAROTROPIC FILTERED MODEL ATMOSPHERE

By expressing the stream function in terms of the symmetric and the antisymmetric components with respect to the equator,the barotropic vorticity equation can be separated into two equations,one describing the behaviours of the atmospheric symmetric motion,and the other those of the atmospheric antisymmetric motion.From them,for the entire global surface at the equivalent barotropic level,the conservations of several basic quantities,such as vorticity,angular momentum etc.in the symmetric and antisymmetric cases,have been discussed.In addition,the energy budget equations and the energy conservation expressions for the two kinds of motion are given.It can be seen from them that there are not only the conversion between the zonal mean kinetic energy and the disturbed kinetic energy in the atmosphere,but also the conversion between the kinetic energy generated by the symmetric and antisymmetric motions.In the case of including orography and horizontal diffusion into the vorticity equation,a mechanism of the generation of asymmetric behaviours of the atmosphere is proposed.The results show that the asymmetric distribution of orography and that of horizontal diffusion coefficients are likely the causes leading to the asymmetric motion.Finally,a theoretical comparison between the global model and the hemispheric one from the physical point of view is made.     

卫星云图处理系统

本文介绍了以微型计算机(IBM—PC)为基础的同步气象卫星云图处理系统,论述了数据采集、分层显示、投影变换以及边缘勾划等功能的实现,並提出若干特殊处理的方法。     

黑水5.4级地震前地倾斜的异常特征及有关问题的讨论

1978年7月13日四川省黑水5.4级地震前,附近温江地区五个台的地倾斜显示出了几种短临异常特征,即震前10余天倾斜单分量日均值曲线出现了大幅度的变化;倾斜的速度变快;震前倾斜矢量打结,结的长轴方向基本指向震中,出结方向背向或指向地震方向;震前几天倾斜方向发生偏差等。这些异常是预报地震的依据之一。     

Tschebyscheff 函数在大气模式垂直离散问题中的应用

文章就常用全球谱模式中的垂直离散问题进行了讨论，给出了用Tschebyscheff函数积分静力方程、连续方程，以及计算垂直平流、垂直扩散等的方法。还对某些气象要素在垂直方向微商呈现间断的问题进行了分析，指出了其中存在的问题和应采取的措施。     

桂北四堡群火山岩形成环境及构造意义

通过野外地质、岩石化学、稀土配分、微量元素等的综合分析表明,桂北四堡群火山岩形成于火山岛弧的构造环境,由四堡群组成的地质体是中元古代位于扬子大陆边缘以南的岛弧地体,中元古代末期该地体与扬子大陆边缘发生碰撞拼贴造山作用,这一作用决定了中、晚元古代桂北及邻区的大陆边缘构造及其演化过程。     

南岳雨凇分析

分析了南岳雨凇与冷冬及西太平洋副热带高压的关系。结果表明,在冷冬年份,南岳雨凇日数偏多;在暖冬年份,南岳雨凇日数偏少。西太平洋副热带高压与南岳冬季气温密切相关。副热带高压偏弱时,南岳冬季偏冷;副热带高压偏强时,南岳冬季偏暖。副热带高压的588线北界偏北时,南岳冬季偏暖,反之偏冷。副热带高压的西伸脊点偏东时,南岳雨凇日数偏多,反之偏少,而且西太平洋副热带高压的变化超前于冷暖冬的变化。     

The petrochemistry characteristics and petrogenesis of peraluminous granite in Tibet

There are 61 major peraluminous granitic bodies in Tibet (TPGs) along the south of the Bangong Co-Gêrzê-Amdo-Nujiang suture, whose lithology includes tourmaline granite, muscovite granite and two-mica granite. The TPGs have SiO₂ = 65.7%−79.52%, K₂O + Na₂O = 2.20%−12.51%, K₂O/Na₂O = 0.49−1.04 and A/CNK = 1.04−1.38. Al₂O₃ gradually decreases and the other oxides disperse with the increase in SiO₂. The rock series is mainly calc-alk series with high potassium. It has typical characteristics of strongly peraluminous granite. Based on the aluminum saturation index and QAP plots, the peraluminous granite plot is mostly within the continental collision granite (CCG) field, indicating that the peraluminous granites in Tibet formed in a continental collisional setting. Ab-Or-Q-H₂O phase diagram indicates the pressure of 0.5 × 10⁸−2 × 10⁸ Pa in TPGs, from which it can be deduced that the forming temperature was under 700°C. The TPGs mainly occurred at the collision stage between two continental crust plates, and the original magma is rooted in the remelting from the upper crust. It is the S-type granite in petrogenesis. The South Gandise belt and the Lhagoi Kangri belt have similar characteristics, suggesting that the two belts have the same magma source and the same tectonic setting. Translated from Acta Geologica Sinica, 2006, 80(9): 1329–1341 [译自: 地质学报]     

Analytic stage–discharge formulae for flow in straight trapezoidal open channels

Analytic stage–discharge formulae are derived for flow in straight trapezoidal channels, based on the 2D analytic velocity distribution in open channels given by Shiono and Knight [Shiono K, Knight DW, Turbulent open-channel flows with variable depth across the channel. J Fluid Mech 1991;222:617–46]. A simple hand-calculation method is provided. Legendre incomplete elliptic integrals of the first and second kinds and a binomial series expansion are used in the derivation of these analytic formulae, together with physically based hydraulic parameters, such as local friction factor (f), dimensionless eddy viscosity (λ) and secondary flow (Γ). The stage–discharge results obtained from the formulae are shown to be in good agreement with experimental data, as are the corresponding analytic velocity and boundary shear stress distributions. The influences of f, λ and Γ on the stage–discharge relationship are also discussed.     

Numerical modeling of geothermal groundwater flow in karst aquifer system in eastern Weibei,Shaanxi Province,China

The quantitative assessment of geothermal water resources is important to the exploitation and utilization of geothermal resources. In the geothermal water systems the density of groundwater changes with the temperature, therefore the variations in hydraulic heads and temperatures are very complicated. A three-dimensional density-dependent model coupling the groundwater flow and heat transport is established and used to simulate the geothermal water flow in the karst aquifers in eastern Weibei, Shaanxi Province, China. The multilayered karst aquifer system in the study area is cut by some major faults which control the regional groundwater flow. In order to calibrate and simulate the effect of the major faults, each fault is discretized as a belt of elements with special hydrological parameters in the numerical model. The groundwater dating data are used to be integrated with the groundwater flow pattern and calibrate the model. Simulation results show that the calculated hydraulic heads and temperature fit with the observed data well.     

Toxicity of Ionic Liquids

The dramatic growth in ionic liquid research over the past decade has resulted in the development of a huge number of novel ionic liquids, as well as many associated applications. The perceived environmentally friendly nature of ionic liquids, which results from their negligible vapor pressure, is now under scrutiny since although they will not evaporate into air, it is not possible to guarantee that they will never enter the environment. Toxicity research studies including ecotoxicity, have recently received broad attention and the commonly accepted notion that ionic liquids have low toxicity has been shown to be incorrect. This review attempts to highlight the progress of ionic liquid toxicity research, as well as the development of degradable and bio‐renewable ionic liquids.