Ac Alternating current (ac) is electric current that alternates between a positive maximum value and a negative maximum value at a characteristic frequency, usually 50 or 60 cycles per second (Hertz).
交流交流是指电流在正负最大值之间以特定的频率变动，通常频率为50或60赫兹。
To cast it in less negative terms, it is better to think of this as taking advantage of a rare opportunity — and it is too good a one not to lever to its maximum potential.
但是从积极的角度来考虑，这不啻为一次难得的机会——不利用来发挥自己的最大潜力实属可惜。
A great portrait photographer considers shapes, lines, framing, angles, negative space, where to place the point of focus in the frame for maximum impact, and so on.
一个伟大的人像摄影师考虑形状、构图、框架、角度、负空间、以及把焦点设置在哪里可以获得最大的视觉冲击等等。
An new approach which united per-particle maximum likelihood data association and negative information technology was adopted to handle the uncertainty of data association for FastSLAM.
采用一种基于单个粒子的最大似然数据关联和环境否定信息相结合的方法来解决未知环境中的数据关联问题。
A measure composed of the actual negative entropy divided by the maximum possible entropy using the same set of signs.
由实际的负熵除以使用同一符号集的最大的可能熵构成的一种量度。
Under a very simple constrain from the Maximum Entropy Principle, we found that an intensity-duration relation of Precipatation processes obeys negative exponent law.
本文从熵极大原理出发导出了在一次降水过程中降水强度与其历时为负指数关系。
Compared with conventional beam pumping unit, the swing-rod beam pumping unit can reduce the maximum crank axle torque markedly, reduce and even eliminate negative crank axle torque.
同常规型游梁式抽油机比较，该机型可以显著降低曲柄输出轴的最大扭矩，减小甚至消除负扭矩，在降低能耗的同时改善了减速箱的受力状况。
The maximum rainfall is just below the positive vorticity center and at the west of the negative vorticity center.
特大暴雨出现在中低层辐合、高层辐散的正涡度中心下方和负涡度中心西侧；
Its maximum axial and tangential velocity attenuate proportionally with the negative index of its distance from the nuzzles.
旋转射流截面最大轴向速度和切向速度与喷距的负指数成正比关系衰减。
Its positive influences will be made full use and negative ones will be overcame to the maximum as long as correct actions are taken.
只要因势利导，采取正确的对策，就能充分利用人民币长期升值的正面影响，最大限度克服其负面影响。
Electroplating technological parameter includes factors of ampere density, temperature, PH value, stir, negative and positive pole. The maximum influencing factor is ampere density.
电镀工艺参数主要包括电流密度、温度、PH值、搅拌、阴阳极和换向电流等因素，其中影响最大的是电流密度。
Recently, the two negative-index relations have been deduced by the principle of the maximum entropy and confirmed by a lot of observation.
近年来，从熵最大原理的角度曾推导出其中的两个负指数关系，并被大量的观测所证实。
Average and maximum activities of SPS were negative correlated with starch contents as well as average rate of accumulations of starch.
SPS酶的平均活性和最大活性与淀粉含量和淀粉积累平均速率呈负相关。
What's worse is that most people have only about a dozen words, maybe a maximum of 20, to describe their consistent emotions. And of these, usually half-or more-are negative.
更糟的是大部分人只用十几个，可能最多20个来形容起惯常的情绪。其中一般有一半或更多是消极的。
The maximum value of positive and negative horizontal velocity increases gradually with the decrease of the water depth in the shoaling process.
另者，孤立波的边界层速度于浅化过程中正向与负向的极值速度有逐渐增加的趋势产生。
The trough is the maximum negative amplitude or downward deflection of the wave.
波谷是子波最大负振幅或向下的偏离。
For strong anisotropy crystal, the maximum incident Angle that yields the negative refraction could be very large.
各向异性强的晶体实现负折射的入射角范围可能会很大。
The EW-trending strain variation along the western margin is the maximum and it is characterized by the alternatively positive and negative variations from the west to the east;
东西向应变西边缘变化最大。 此外，由西向东还具有正负交替的变化特征；
Retain newline. A non-negative size argument limits the maximum number of bytes to return (an incomplete line may be returned then). Return an empty string at EOF.
读取文件的一行，保留换行符，到文件末尾返回空串。
When electrode negative ratio is zero, which is using MIG welding with DC ami welding wire being positive polarity, weld penetration is maximum , wire melting speed and deposition rate are minimum;
当负极性比率等于零即直流且焊丝为正极性的MIG焊时，其焊缝熔深最大，焊丝熔化系数最小，熔敷速度最小；
Recycling and reuse is a reasonable method for construction debris, there will be benefit to protect natural resources and maximum reduce the negative effect on natural environment.
将建筑废料经过回收处理后再重新利用，既能保护天然资源，又能降低建筑垃圾对环境的影响，为该问题提供了一个合理的解决办法。
Recycling and reuse is a reasonable method for construction debris, there will be benefit to protect natural resources and maximum reduce the negative effect on natural environment.
将建筑废料经过回收处理后再重新利用，既能保护天然资源，又能降低建筑垃圾对环境的影响，为该问题提供了一个合理的解决办法。
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