The upper mixed layer during coastal upwelling events on the northern portugal shelf

The upper mixed layer (UML) depth obtained from temperature is very close to that from density:the maximum is about 15m. This indicates that temperature is a good indicator of mixed layer during measurements. When the surface heat flux is balanced by a cross-shore heat flux, the surface mixed layer depth obtained from the WM model (Weatherly and Martin, 1978),hPRT, is roughly the same as observed. The mixed layer depth calculated from the PWP model (Price, Weller and Pinkel, 1986) is close to the depth obtained from thermistor chain temperature data. The results show that both the WM model and PWP model can provide a good estimate of stratification in the study area during the cruise. The value of log( h/u3) is about 9.5 in the study area, which shows that the study area is strongly stratified in summer. Observations on the northern Portugal shelf reveal high variability in stability, giving rise to semi-diurnal, semi-monthly and diurnal oscillations, and long term variations. The fortnightly oscillatio     

A mixed mid-Permian marine fauna from the Yanji area, northeastern China: A paleobiogeographical reinterpretation

Abstract Paleobiogeographically mixed marine faunas have been well recognized from many Permian marine sequences in northeast China. These mixed faunas are normally associated with Monodiexodina fusulinid assemblages. The mixed faunas are characterized by an admixture of both paleo-tropical Cathaysian taxa and cool-temperate elements. In addition, endemic taxa, especially at a specific level, and anti-tropical forms, are also very distinctive.
Previously, the presence of anti-tropical taxa in these mixed faunas has been used to argue that some of the northeast Asian terranes may have originated from northern Gondwana during the Permian, where they may have been m close proximity to Tibet. However, this interpretation is contrasted by the view offered in this paper. It is argued that the anti-tropical distribution of marine taxa is a normal, predictable biogeographical phenomenon that is probably controlled by certain climatic conditions. Permian anti-tropicality seems to have occurred most strongly during the Late Artinskian to Ufimian, probably in association with the presence of distinct mesothermal climatic zones at the time. In the present study we report a mixed mid-Permian marine fauna (fusulinids and brachiopods) from the Dasuangou Formation of the Yanji area in the eastern Jilin Province of northeast China, and discuss its possible origin in the context of Permian paleogeography and the climates of eastern Pangea.     

Nodal and Mixed Finite Elements for the Numerical Homogenization of 3D Permeability

The aim of upscaling is to determine equivalent homogeneous parameters at a coarse-scale from a spatially oscillating fine-scale parameter distribution. To be able to use a limited number of relatively large grid-blocks in numerical oil reservoir simulators or groundwater models, upscaling of the permeability is frequently applied. The spatial fine-scale permeability distribution is generally obtained from geological and geostatistical models. After upscaling, the coarse-scale permeabilities are incorporated in the relatively large grid-blocks of the numerical model. If the porous rock may be approximated as a periodic medium, upscaling can be performed by the method of homogenization. In this paper the homogenization is performed numerically, which gives rise to an approximation error. The complementarity between two different numerical methods – the conformal-nodal finite element method and the mixed-hybrid finite element method – has been used to quantify this error. These two methods yield respectively upper and lower bounds for the eigenvalues of the coarse-scale permeability tensor. Results of 3D numerical experiments are shown, both for the far field and around wells.     

Mantle flow with existence of plates and generation of the toroidal field

The observed plate velocities contain two types of motions. The poloidal component is related to the formation of ridges and subduction zones and the toroidal field expresses the shearing of surface plates. One very important consideration in modeling flow in the earth's mantle is the existence and motion of the lithospheric plates. The motion of plates represents a large-scale circulation with strong viscous coupling to the mantle underneath. The mantle flow probably is neither a purely free convection driven by buoyancy forces due to nonadiabatic temperature gradients in the mantle nor a forced convection generated by boundary forces, but a mixed convection that combines the effects of boundary and buoyancy forces. We present, in this paper, the mixed convection model resulting in a surface velocity field that contains both the observed poloidal and toroidal components.     

编程求解混合层高度的方法

在t-lnp图上利用08时、14时气压和最低气温、最高气温，经过坐标转换求解早晨、中午混合层的气压和温度，然后根据等温大气压高公式计算混合层高度。该计算方法用VB6．0编程，可自动从当日报文中读取数据，计算出混合层高度值，也可根据数值预报结果计算次日混合层高度。     

Time‐domain analysis of unbounded media using mixed‐variable formulations

Formulation of a matrix‐valued force–displacement relationship which can take radiation damping into account is of major importance when modelling unbounded domains. This can be done by means of fundamental solutions in space and time in connection with convolution integrals or by means of a frequency dependent boundary element representation, but for discrete frequencies Ω only. In this paper a method for interpolating discrete values of dynamic stiffness matrices by a continuous matrix valued rational function is proposed. The coupling between interface degrees of freedom is fully preserved. Another crucial point in soil–structure interaction analysis is how to implement an approximation in the spectral domain into a time‐domain analysis. Well‐known approaches for the scalar case are based on the partial‐fraction expansion of a scalar rational function. Here, a more general procedure, applicable to MDOF‐systems, for the transformation of spectral rational approximations into the time‐domain is introduced. Evaluation of the partial‐fraction expansion is avoided by using the so‐called mixed variables. Thus, unknowns in the time‐domain are displacements as well as forces. Copyright © 2001 John Wiley & Sons, Ltd.     

多源遥感影像的去云层处理

针对多源遥感影像的云覆盖问题，提出了利用多项式改正算法，以实现不同遥感影像之间的局部影像替换，从而满足去除目标影像上云覆盖的要求。     

宝山铅锌银矿床混合矿石中银矿物的赋存状态

本文通过电子探针分析、光学显微镜观察等，确定了矿石中银的矿物名称和化学组成，查明了银矿物的粒度大小及在矿石中的分布，指出方铅矿是银的主要载体矿物。     

用混合算法计算电偶源瞬变电磁响应

从水平层状介质表面上垂直磁偶源瞬变电磁响应的计算公式出发,根据互换原理,得出目前常用的以电偶极源发射、在中垂线两侧张角为θ范围内用线圈测量感应电动势装置的正演计算公式,用M. M. Goldman提出的混合算法计算水平层状介质电偶极源的瞬变电磁响应,计算结果证明了混合算法的优越性。     

考虑土-结构相互作用的结构控制H2/H∞混合凸优化方案

在地震信号和建筑结构系统的防数分析基础上，使用了混合控制优化指标J作为优化目标，并给出其物理含义。考虑土－结构相互作用的影响，针对H2控制方案和H∞控制方案的优缺点，通过LMI凸优化方法求解混合控制器，给出了在给定γ值的前提下极小化指标J的H2／H∞混合控制方案，并给出了仿真算例。