自由空间

Laser beam' s acqusition, pointing and tracking is one of key technologies of free space optical communication.

光束的捕获、对准和跟踪是自由空间光通信中必须解决的关键技术之一。

This means that for every megabyte that you want to back up, you have to have that much free space on your drive (for the .dmg to be created).

这意味着，每兆字节，您要备份，你必须有很多自由空间的驱动器。

MIMO free space optical communication based on orthogonal space time block code.

基于正交空时块编码的MIMO自由空间光通信。

Quantified environment model was the basis for quantitative study on path planning of mobile robots.By using free-space method,the two-dimensional weighted network topology was created according to mobile robot environment.The path length of environment was modeled with length matrix and the path width of environment was modeled with width matrix.

移动机器人工作环境的定量建模是移动机器人路径规划定量分析的基础，采用自由空间法，建立移动机器人工作环境的二维带权网络拓扑模型，模型中的长度矩阵描述工作环境的路径实际长度，宽度矩阵描述工作环境的路径实际宽度。

A measure of the effect of the medium on the magnetic field B when subject to a magnetizing force H: B = 0 in SI system, B = H + 4πI in cgs system, where 0 is the permeability of free space.

是介质在磁场 B 中所受磁化力为 H 时产生的效应：在国际单位制中 B = 0 在厘米-克-秒制中 B = H + 4πI 其中 0 为自由空间磁导率。

The unit of measure for H in the SI or mks system is ampere turns/meter and in the cgs system, the oersted (1 amp turn/m = 4π 10-3 oersted = 4π 10-3 gilbert/cm). 0 is called the permeability of free space; 0 = 4π 10-3 weber/amp-m in SI units and 1 gauss/oersted in cgs units.

H 在国际单位制或在米-千克-秒单位制中的度量单位是安培匝/米，在厘米克-秒单位制中为奥斯特(1 安培匝/米= 4π 10-3 奥斯特= 4π 10-3 吉伯/厘米) 0 为自由空间导磁率；0 = 4π 10-3 韦伯/安培米=1 高斯。

Magnetic permeability: The ratio of the magnetic induction B to the inducing field strength H; denoted by the symbol :=|B|/0|H| 0 is the permeability of free space = 4π 10-7 weber/ampere meter (or henries/meter) in the SI system and 1 gauss/oersted in the cgs system, so that the permeability is dimensionless.

磁导率 磁导率：磁感应强度 B 与源场强度 H 之比，用符号表示：=|B|/0|H|自由空间磁导系数 0 在国际单位制中为 4π 10-7 韦伯/安培米，在厘米-克-秒单位制中为 1 高斯/奥斯特。因此磁导率是无量纲的。

The surface waves propagate with a phase velocity which is always less than the velocity of ectromagnetic waves in free space.

面波传播速度的阶段，始终是比ectromagnetic波在自由空间速度减少。

The photophone used free-space light to carry the human voice 200 meters.

当时，这光电话用自由空间光将人类的声音传送到200米之远。

Among mesons, the lightest and most important one is certainly the pion, thus it is no accident that its structure, properties (both in free space and in nuclear matter) and interactions with nucleons and nuclei have gotten considerable attentions in the past and again at the present time.

在各种介子中，π介子是最轻且最重要的介子，关于自由空间中π介子的结构与性质、核介质内π介子的性质、π-核子相互作用与π-核相互作用等问题，始终受到相当多的关注。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。