查询词典 modulation

The results showed that:(1) The characteristic frequency of IC neurons of house mouse was increased with increasing recording depth, and the masker intensity used was positive relevant to the IC neurons\' minimum threshold. When the minimum threshold was high, the masker intensity needed was loud, vice versa.(2) According to the masking rate at MT+10dB of IC neurons to frequency modulation and tone burst, the IC neurons were classified as three types: type I neurons ( 72/113, 63.7%), in which the masking effect of TB was better than frequency modulation ;type II neurons (32/113, 28.3%), in which the masking effects of the two maskers were same; type III neurons( 9/113, 8.0%), in which the masking effect of FM was better than TB.(3) Type I neurons, the minimum threshold of which was low, but the Q_(10) and DR values of which were large; in type III neurons, the minimum threshold was high, the Q_(10) and DR values were narrow; in type III neurons, the MT Q_(10) and DR values were in between.(4) Both FM and TB could make the MT of type I neurons shift upward distinctively, but the effect of TB was more significant than FM.(5) The Q_(10) values of type I neurons became narrower under the influence of TB, were unaffected under the influence of FM.

结果显示：(1)小鼠下丘神经元的特征频率随着记录深度的增加而增高，掩蔽声强度与神经元的最小阈值呈正相关，即对高最小阈值的神经元进行掩蔽时需要的掩蔽声强度高，对低最小阈值神经元进行掩蔽需要的掩蔽声强度低：(2)根据调频声(frequency modulation， FM)和短纯音(tone burst， TB)对下丘神经元阈上10dB处反应的掩蔽，将小鼠IC神经元分为三类：Ⅰ类神经元(72/113，63.7％)，短纯音的掩蔽效果比调频声更好；Ⅱ类神经元(32/113，28.3％)，两者对神经元声反应的掩蔽率相同；Ⅲ类神经元(9/113，8.0％)，调频声的掩蔽效果更好；(3)Ⅰ类神经元的最小阈值低、Q_(10)值和动态范围大，Ⅲ类神经元最小阈值高、Q_(10)值和动态范围小，Ⅱ类神经元的最小阈值、Q_(10)值和动态范围介于Ⅰ和Ⅲ类神经元之间；(4)短纯音和调频声都可以使Ⅰ类神经元声反应的最小阈值明显上移，但短纯音使神经元最小阈值的上移更显著：(5)短纯音使Ⅰ类神经元的Q_(10)值变小，调频声使神经元的Q_(10)值增大不显著，短纯音与调频声对神经元Q_(10)的影响差别显著；(6)短纯音与调频声都使神经元的动态范围减小，并且作用显著，但短纯音的效果更显著：(7)短纯音与调频声都使神经元反应的潜伏期延长，效果显著，但TB的延长作用更为显著；(8)随着探测声强度的升高，短纯音和调频声对Ⅰ类神经元声反应的掩蔽率都降低，但在各个探测声强度短纯音的掩蔽率都比调频声高。

First, a series of liquid crystal polymers with different amounts of cholesterol mesogens and ferroelectric property are synthesized in this research. The structures of the compound synthesized are confirmed by IR and 1H-NMR spectroscopy. The thermal properties are characterized by DSC, POM. In this research, the 3-D molecular arrangement of molecular were measured by Polarization Modulation-Attenuated Total Reflection-Flourier Transform Infrared spectroscopy (PM-ATR-FTIR).

中文摘要本研究分成两个部分，第一部分为合成铁电性液晶及胆固醇液晶，以FTIR及 1H-NMR来鉴定化合物的结构，并以POM观察其液晶特有的光学纹路，用DSC来观察矽氧烷类液晶的液晶相的热转移温度并利用偏光-衰减全反射-傅立叶转换红外线光谱仪(Polarization Modulation-Attenuated Total Reflection – Flourier Transform Infrared)来探讨矽氧烷类液晶分子的三度空间排列。

Based on the analysis of the affected extent of the neutral-point potential by every space vector on all kinds of voltage and current conditions the concept named neutral point control grade was proposed for the first time in this paper. The calculation formulas of NPCG were presented as well. Based on NPCG, a novel modulation scheme called optimized 3D space vector modulation (O3DSVM) scheme was proposed in a-b-0 coordinates based on the translation principle of axes, by which the space vectors with higher NPCG values are selected to synthesize the object vector to suppress the unbalance of the neutral-point potential.

该文通过对各种电流电压状态下每个三维空间矢量对直流中点电位的影响进行分析，提出了"中点控制度"(neutral-point control grades，NPCG)的概念，并给出了NPCG的计算公式；基于NPCG，在a-b-0坐标系下提出一种基于坐标平移原理的新型"三维矢量优化选择调制策略"(optimized 3D space vector modulation，O3DSVM)，该调制策略能优化选择NPCG值较高的矢量以合成目标矢量，从而达到最大程度控制直流中点电位偏移的目的。

In addition, by contrast with the common Space Vector Modulation strategy, it has the capability of self-compensation when it comes to the situation of three-phase Grid Voltages Unbalance, as well as advantage of low tripper components.

与常规空间矢量调制算法(Space Vector Modulation ， SVM)相比较，该算法具有输入电流和输出电压谐波含量小的优点，且当三相电网电压失衡时，能够自动进行补偿。

To eliminate common-mode voltage of cascaded multi-level inverter, three kinds of phase-difference SVM based on left and right bridge vectors are proposed firstly. From these three modulations, equivalent SPWM components are deduced, and the unipolarity and bipolarity of output waveforms are analyzed. 2π/3 PD-SVM (phase-difference space vector modulation) is testified be unipolar.

为消除级联型多电平逆变器的输出共模电压，首先提出了基于左、右桥臂矢量的三类相差空间矢量调制(space vector modulation，SVM)技术，数学推导出三类调制技术的等效正弦脉宽调制(sine pulse width modulation，SPWM)的调制波，并分析了其各自相电压输出波形的单、双极性，证明2π/3相差SVM必为单极性调制。

Modulation offers the advantage of spreading out a frequency selective fading over many symbols, which effectively randomizes burst errors caused by fading or impulse noise, so that instead of several adjacent symbols being completely destroyed; many symbols are only slightly distorted.

modulation提供延长一频率有选择性退色的好处在许多标志，有效地随机化退色或脉冲噪声造成的猝发错误，因此而不是完全地被毁坏的几个毗邻标志；许多标志少许被变形。

Multi-carrier modulation offers the advantage of spreading out a frequency selective fading over many symbols, which effectively randomizes burst errors caused by fading or impulse noise, so that instead of several adjacent symbols being completely destroyed; many symbols are only slightly distorted.

多载体 modulation提供延长一频率有选择性退色的好处在许多标志，有效地随机化退色或脉冲噪声造成的猝发错误，因此而不是完全地被毁坏的几个毗邻标志；许多标志少许被变形。

The amount of pulse width modulation pulse generators of the proposed modulation strategy is only the half of that of the traditional modulation strategy, which is of significant theoretical and practical value for the digital implementation of cascade multilevel converter.

该策略较传统的载波相移SPWM可以节省一半的脉宽调制(pulse width modulation，PWM)脉冲发生器，对级联型多电平逆变器的数字化实现有重要的理论和实用价值。

The mathematical model and working modes of a novel three-phase two-arm three-level neutral-point-clamped pulse width modulation rectifier suitable for direct-driving wind power system are analyzed in detail, and the constant frequency control strategies based on space voltage vectors are proposed and applied to the rectification conversion of direct-driven power generation system.

系统分析了新型三相两桥臂三电平中性点箝位脉宽调制(pulse width modulation，PWM)整流器的数学模型和工作模式，提出了基于空间电压矢量的恒频控制策略，并将其应用于直驱风力发电系统整流变换中。

The most popular solution to this question is using group adaptive modulation system, and usually group modulation type is decided by the subcarrier which has the worst channel information.

一个最常见的解决方法就是使用group adaptive系统，而通常决定group modulation type的方法都是使用最差的subcarrier的通道资讯。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了