对流

This makes more and more people pay more attention to studies and applications of numerical simulation in thermal recovery. In this research, we have developed a reliable mathematical model for thermal recovery, which takes a full consideration of the effect of viscos, gravitical and capillary forces on the three-phase flow of gas, water and oil, the effect of the temperature on the medium characteristics of liquid and solid, the phase equilibrium of gas-liquid in each component, heat transportation including connection, conduction and radiation as well as heat losses in both the overburn and underlying strata. In the space discreation of the mathematical model, we have proposed a new method based on the improvement of the conventional nine-points difference approximation, which has a higher difference accurancy.

本项研究以热力采油的主要机理为基础，充分考虑在粘性力、重力和毛管力作用下油水气三相流动，考虑温度对各种流体和固体介质物性的影响，考虑每一组分中汽液两相的相平衡，考虑热在地层中的传导、对流和辐射以及上下盖层的热损失，利用热力学第一定律、质量守恒定律和流体迁移定律，建立了正确可靠的注蒸汽数学模型；在对数学模型进行空间离散时，利用控制有限体积积分法，对以往的九点差分近似作了合理的改进，使其具有较高的差分近似精度：结果表明，该公式的近似精度要比以往文献中所给的九点差分近似精度高，可以认为，在油藏数值模拟中，如果遇到非均质情况，使用这种九点差分近似更合理。

According to the precise time-integration method, this paper discusses the parallel algorithm for whole domain and subdomain precise integration of diffusion equation.

讨论了一维扩散方程的全域精细积分和子域精细积分的并行算法，给出了对流扩散方程的子域精细积分并行算法，其精度优于单点精细积分法。

As EFCI switch is considered, flaw of existing two-phase analysis model is pointed out, and four-phase single bottleneck simple model is advanced. With this model, the effect caused by typical control parameters is studied and analyzed. As more indepth research, the double bottleneck complex model is further brought forward.

就EFCI型交换机而言，论文指出了已有的两阶段分析模型存在的缺陷，并提出了改进的四阶段单瓶颈简单分析模型，利用它分析和讨论了各个控制参数对流控过程产生的影响。

The flow regime in downcomer can be divided into two kinds: cross flow injection and impingement. Cross flow injection only takes place under low injection flow rate in dowcomer flow. The investigation on flow regime and heat transfer in RPV under PTS is for the first time in China.

在国内本实验是第一个研究下降环腔内的流动与传热，在国际上，象这样同时进行了流动可视化，常温常压下传热和高温高压下传热的实验也不多，特别是针对下降环腔内对流换热系数的研究，在公开文献中还没有相类似的实验。

Severe thunderstorms are associated with intense convection , often resulting in violent downdraft and heavy rain

强烈的雷暴与剧烈对流有关，经常会带来猛烈的下沉气流和大雨。

The cell-like appearance is formed by the multitude of small clusters of magnetic flux that are collected in the downflow regions of the supergranular network of convective motions.

该细胞是一样的外观形成的磁通量是在对流运动supergranular网络的下流地区收缴的小群，众说纷纭。

A baffle wall located inside containment is used to establish within containment an air upflow path and an air downflow path in convective exchange.

位于外壳内的缓冲壁用于在外壳内建立进行对流交换的上气流通路和下气流通路。

There exists four different parts in local basin thermal circulation: cold downslope wind at nighttime, converctive boudary layer development and cold air lake disappearance in morning, thestrong upslope wind system at noon, and circulation reversal around sunset time.

盆地热力环流存在四个明显的分区，即夜间冷下坡风和冷湖的堆积，清晨对流边界层的发展和冷湖的弥散，正午时分强热力上升环流和日落前后热力环流的逆转。

A mesoscale convergence line, which is formed by downslope wind from the Taihang Mts. Converging with southwest warm humid wind in front of a surface trough, induces the release of the CAPE and initiates convection and organizes the convective cells into a squall line.

由于太行山地形影响而产生的下坡风与地面低压槽前的西南暖湿气流相汇合，形成中尺度辐合线，触发了不稳定能量的释放，产生对流并由中尺度辐合线组成飑线。

The thesis reviews the concerned study status of domestic and overseas first, then make factor analysis for ice flood, Partial Least-square model, Artificial Neural Network based on Genetic Algorithm model, Support Vector Machine model for ice drift, ice freeze and ice break are established. The results are reasonable and precise.

首先阐述了国内外有关研究现状，然后对影响黄河宁蒙段凌汛的三大因素(热力因素、动力因素、河势因素)进行了理论分析，在此基础上分别对流凌日期、封河日期和开河日期研制了偏最小二乘回归模型、改进人工神经网络模型和支持向量机模型，试预报结果表明，所建立模型精度高，预报结果令人满意。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。