THE EFFECTS OF EXTERNAL FORCING,DISSIPATION AND NONLINEARITY ON THE SOLUTIONS OF ATMOSPHERIC EQUATIONS*

Based on the primitive equations of the atmosphere,we study the effects of external forcing.dissipation and nonlinearity on the solutions of stationary motion and non-stationary motion.The results show that the asymptotic behavior of solutions of the forced dissipative nonlinear system is essentially different from that of the adiabatic non-dissipative system,the adiabatic dissipative system,the diabatic non-dissipative system and the diabatic dissipative linear system,and that the joint action of external forcing,dissipation and nonlinearity is the source of multiple equilibria.From this we can conclude that the important actions of diabatic heating and dissipation must be considered in the models of the long-term weather and the climate.     

台风区和外围暴雨区的旋转风、散度风动能收支

用完全的散度风(v_D)和旋转风(v_R)动能收支方程对8116台风和8407台风以及8116台风与其外围暴雨区的关系作了讨论。结果表明:台风区的有效位能通过散度风动能(K_D)转换为旋转风动能(K_R).台风向区域外部输出动能,在暴雨区上空通过涡度、散度场相互作用的转换机制由K_R向K_D转换,散度风加大触发对流发展产生暴雨,这可能是台风与其外围暴雨联系的一种能量过程。     

龙门山地区泥盆纪碳酸盐与硅质碎屑的混积相与混积机理

碳酸盐与陆源碎屑的混合沉积研究至今尚未引起足够重视。文献屈指可数。扬子西经缘龙门山地区盆纪发育了了这类良好的混合沉积。作者根据实际材料，首次从这一思路出发，识别该区泥盆纪Ｅｍｓｉａｎ期到Ｇｉｖｅｔｉａｎ早期的混积相四种，混积亚相约１４种，阐明了其优势混积作用；根据混积作用特征、沉积背景关系，划分出两大混积类型，即泥质背景下的混积１型和砂灰质背景下的混积Ⅱ型；对混积作用机理进行了探讨；并指出不同级次     

陕西洛南陶湾群三岔口组砾岩研究

陶湾群三岔口组砾岩是一套分布于华北地块南缘的水下碳酸盐岩型重力流沉积，砾岩的形成同商州铁炉子栾川断裂带早期活动性质存在因果关系。通过１∶５万区调填图发现，陶湾群三岔口组砾岩从母岩区到砾岩堆积区之间无断陷作用；沉积基底基本连续；砾岩沉积组构出现有序的横向变化规律，依次为母岩区层状白云岩（α区）、具有垂向张裂隙及流动构造的始滑区白云岩（β区）、具有节状构造的滑移区白云岩（γ区）和砾岩堆积区（δ区）。陶湾群三岔口组砾岩时代厘定为早寒武世晚期至中寒武世，这也是华北地块南缘盆地环境的主形成期，砾岩是在东秦岭洋向华     

固体粒子的稳泡机理

固体粒子是良好的稳泡剂，其稳泡作用实质是在气－水界面产生吸附，形成固态膜，固态膜致密性强，机械强度高，表面粘度大。固体粒子的润湿性能，粒子大小及形状对固态膜的牢固程度有很大影响。     

铂族元素迁移富集机理的新探

在岩浆及高温热液中，拍族元素以纳米液态铂族元素单质、铂族元素与其它金属元素的纳米液态合金、纳米液态铂族元素的硫、砷化物迁移。在中、低温热液及表生条件下，除呈上述固态纳米铂族矿物随流体迁移外，还呈配合物形式迁移。然后它们在合适的条件下沉淀富集形成矿床。此外，还讨论了铂族元素与金地球化学条件的异同。     

The mechanisms of shallow earthquakes and the monitoring of a comprehensive test ban

The ability of seismological criteria to identify earthquakes from underground explosions depends partly on the orientation of the earthquake source. Well-determined double-couple moment tensor solutions for a large number of earthquakes have been published in the Harvard centroid moment tensor (CMT) and United Slates Geological Survey (USGS) catalogues. Statistical analyses of these catalogues indicate that the distribution of the orientation of earthquake mechanisms is not random. The distribution of the T axes shows significant clustering around the downward vertical, indicating that a larger number of earthquake mechanisms radiate compressional P -wave energy to teleseismic distances from near the maximum of the radiation pattern than is predicted if earthquake sources are randomly oriented double couples. The clustered T axes correspond to compressional dip-slip mechanisms, and it is this type of mechanism which is believed to cause both the m _b: M _s (the ratio of body-wave to surface-wave magnitude) and first-motion criteria to misidentify an earthquake as an explosion.     

Estimating Climate-Change Impacts on Colorado Plateau Snowpack Using Downscaling Methods

This study develops observed climate-based downscaling transfer functions that are used with general circulation model (GCM) output to assess potential global-change impacts on Upper Colorado Plateau, USA, water resources. Daily automated snow water equivalent stations are used with 700 mb atmospheric circulation to determine empirical transfer functions. Downscaling methodologies using multiple regression and neural networks are evaluated, with the neural network results explaining approximately 70%of the daily snowfall variance. The neural network-based transfer functions are used with the GENESIS GCM to simulate snowfall characteristics in both a 1xCO₂ and a 2xCO₂ climate. While the total precipitation simulated by the 2xCO₂ analysis remains nearly the same as today, less will fall as snow; specifically, snow water equivalence shows significant reduction (except in the Green River Basin) as the snow season is reduced by 58 days on average.     

张家界地貌风光及其产业导向

用遥感技术对张家界地貌进行了研究,分析了张家界地貌的产业导向和开发效益,提出了进一步发展的举措。     

Centroid moment tensor inversion of low-frequency seismic spectra using Green's functions for aspherical earth models

We present a new method for centroid moment tensor (CMT) inversion, in which we employ the Green's function computed for aspherical earth models using the Direct Solution Method. We apply this method to CMT inversion of low-frequency seismic spectra for the 1994 Bolivia and 1996 Flores Sea deep earthquakes. The estimated centroid locations agree well with those obtained by multiple-shock analyses using body-wave data. This shows that it is possible to obtain reliable CMT solutions by analyses of low-frequency seismic spectra using accurate Green's functions computed for present 3-D earth models.