专业英语课外英译汉

Briefly ,air conditioning is necessary for the following reasons .Heat gains from sunlight and electric lighting ,in particular ,may cause unpleasantly high temperatures in rooms ,unless windows are opened .If windows are opened ,then even moderate wind speeds cause excessive draughts ,becoming worse on the upper floors of tall buildings.

简而言之，空调的原因有以下几点是必要的。特别是从阳光和电力照明，发热量，可能会导致令人不快的高温室，除非窗户啊的事。如果窗户是打开的，那么即使中等风速导致通风过度，变得更糟上高楼。

Further , if windows are opened ,noise and dirt enter and are objectionable ,becoming worse on the lower floors of buildings ,particularly in urban districts and industrial areas .In any case ,the relief provided by natural airflow through open windows is only effective for a depth of about 6 meters inward from the glazing.

此外，如果开窗户，噪音和灰尘进入和反感，越来越对建筑物的低层，特别是在城市区和工业区。在任何情况下,所提供的救济自然气流通过敞开的窗户只有有效的深度约6米的玻璃。

It follows that the inner areas of deep buildings will not really benefit at all from opened windows .Coupled with the need for high intensity continuous electric lighting in these core areas , the lack of adequate ventilation means a good deal of discomfort for the occupants .Mechanical ventilation without refrigeration is only a partial solution .

因此，深层建筑的内部区域将不会真正受益于所有打开的窗口，再加上高强度连续照明的需要，在这些核心领域，洛杉矶充足的通风方式对居住者有着很好的不适感，没有制冷的机械通风只是部分的解决方案。

It is true that it provides a controlled and uniform means of air distribution ,in place of the unsatisfactory results obtained with opened windows (the vagaries of wind ,again particularly with tall buildings , produce discontinuous natural ventilation ),but tolerable internal temperatures will prevail only during winter months .For much of the spring and autumn ,as well as the summer ,the internal room temperature will be several degrees higher than that outside ,and it will be necessary to open windows in order to augment the mechanical ventilation.

这是真实的，它提供了一个控制和空气分布均匀，在打开的窗口获得令人满意的结果的地方（风，变幻莫测又特别高建筑物，产生不连续的自然通风，但可以忍受的内部温度只在冬季，春季和秋季，以及夏天，实习生铝室的温度会比外部的高出几度，而且必须打开窗户以增加机械通风。

The essential feature of comfort conditioning is that it aims to produce an environment which is comfortable to the majority of the occupants .The ultimate in comfort can never be achieved , but the use of individual automatic control for individual rooms .

舒适性调节的本质特征是，它的目的是产生一个舒适的环境，对大多数的居住者，在舒适的最终无法实现,但每个人房间的个别自动控制。

简单地说，空调是必要的，原因如下。从阳光和照明电加热的收益，尤其是可能会导致令人不快的高温房间，除非窗户被打开。如果窗户被打开，那么即使是中等风速下会导致过多的草稿，成为对高层建筑的上部楼层差。

此外，如果窗户被打开，噪音和灰尘进入，是反感，在建筑物的楼层较低，特别是在城市地区和工业区。败坏在任何情况下，通过打开的窗口自然通风提供的救济是唯一有效的深度向内的玻璃约6米。

由此可见，深建筑物的内部区域不会真正从打开的窗户。再加上需要高强度连续电照明在这些核心领域受益可言，缺乏足够的通风是指一个很好的不适，为驾乘。机械通风不制冷是只能解决部分问题。

它是真实的，它提供空气分布的控制和统一的手段，在地方的结果不尽如人意打开的窗口得到的（风的反复无常，再次特别是高层建筑，生产不连续的自然通风），但可以容忍内部温度为准只在冬季，对于大部分的春，秋两季，以及夏季，内部室温会几度比外面高，这将是必要的，以增加机械通风开窗。

舒适性空调的基本特点是，它的目标是生产出舒适的大多数居住者的环境，舒适的终极永远无法实现的，而是使用单独的自动控制各个房间。

Fundamental of Fluid Mechanics

Fluid motions manifest themselves in many different ways. Some can be described very easily, while others require a thorough understanding of physical laws. In engineering applications, it is important to describe the fluid motions as simply as can be justified. This usually depends on the required accuracy. Often, accuracies of ±10% are acceptable, although in some applications higher accuracies have to be achieved. The general equations of motion are very difficult to solve; consequently, it is the engineer's responsibility to know which simplifying assumptions can be made. This, of course, requires experience and, more important, an understanding of the physics involved.

Some common assumptions used to simplify a flow situation are related to fluid properties. For example, under certain conditions, the viscosity can affect the flow significantly; in others, viscous effects can be neglected greatly simplifying the equations without significantly altering the predictions. It is well known that the compressibility of a gas in motion should be taken into account if the velocities are very high. But compressibility effects do not have to be taken into account to predict wind forces on buildings or to predict any other physical quantity that is a direct effect of wind. After our study of fluid motions, the appropriate assumptions used should become more obvious. Here we introduce some important general approaches used to analyze fluid mechanics problems and give a brief overview of different types of flow

流体运动以许多不同的方式表现出来。有些人可以很容易地描述，而另一些人则需要彻底了解物理定律。在工程应用中，它是重要的描述的流体运动，只要简单地可以被证明是合理的。这通常取决于所需的精度。通常，在某些应用中，精度为10%是可以接受的，虽然在某些应用中更高的精度必须实现。一般的运动方程是很难解决的，因此，它是工程师的责任，知道可以简化的假设。这当然，需要的经验，更重要的是，了解物理涉及。