低频

Objective To study the effect of extremely low frequency electromagnetic fields on Bax and Bcl2 expression in the spermatogenic cells of rats.

目的 探讨极低频电磁场对大鼠生精细胞凋亡相关基因Bax和Bcl-2表达的影响。

METHODS: Exposed cutaneous branches rooted in rami posterior nervi spinalis and dominated muscles by exciding the median skin at the back of the rat's neck, given electric stimulation to the muscles by Low-frequency pulse transmitter. The output range was Voltage 0-40 V, frequency 1-111 Hz and pulse width 0-1 000 ms.

切开大鼠颈后正中表皮，显露脊神经后支皮支及其所支配的颈部后外侧肌群，使用低频脉冲发射器对上述肌肉进行电刺激，发射器的输出范围为：电压0~40 V，频率1~111 Hz，脉宽0~1 000 ms。

First, using chaotic sequences, an algorithm of embedding watermark in low frequency subband of wavelet transform image is designed.

第一，利用混沌序列的优良性能，提出了一种在小波图像低频系数中嵌入水印及检测的算法。

The subdividing drive is a kind of driving technology that can effectively improve the step precision and characteristic of low frequency.

细分驱动技术是一种有效改善步进电机低频特性和提高步进精度的驱动技术。

Stimulation at this site is typically delivered at low frequencies in contrast to the high frequency stimulation required for therapeutic benefit in the subthalamic nucleus.

在这个位点的治疗刺激一般采用低频刺激而不是像亚丘脑核这样使用高频刺激。

A single peaked tympanogram was typical in normal infants for 1000 Hz admittance,susceptance and conductance tympanograms and there were 28 ears (93.3%), 25 ears (83.3%) and 26 (86.7%) respectively.

在成年人和儿童中，以低频纯音(220Hz或226Hz)为探测音的鼓室声导抗测试被证明对于诊断多种中耳疾病、鼓膜异常以及咽鼓管功能障碍有很好的作用[1，2]，但是目前已经有一些研究表明，它图1高频探测音鼓室导抗图的不同类型。a，b：单峰型；c：无峰型；d：三峰型并不适用于诊断婴儿的中耳病变，特别是年龄小于6个月的婴儿[3-5]。

This mechanism converts satellite signals from high frequency transmittable signals to low frequency signals for local receivers.

这一机制的转换卫星信号从高频transmittable信号，低频信号为本地接收机。

Study of underfrequency load shedding scheme based on load frequency characteristics .

计及负荷频率特性的低频减载方案研究。

A new method of optimizing the Underfrequency load shedding has been developed in the paper.

低频减载是电力系统抑制频率下降、维持系统频率稳定的有效方法。

The purpose of this paper is the analysis、computation and dynamic equivalence of power system frequency dynamics as well as the designation and implementation of underfrequency load shedding scheme. Some important conclusions have been reached based on detail theoretical analyses and a large amount of calculation results.

本文采用理论分析和详细时域仿真相结合的方法研究了复杂扩展式多机电力系统中功率—频率动态过程的主要特点，讨论了频率动态过程的计算方法，解决了频率过程计算中的动态等值问题，同时对电力系统低频减载方案的设计和实施问题进行了深入的探讨。

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。