查询词典 instantaneous

Extract information based on the instantaneous features : In the center is one of the instantaneous rate of the power spectral density of the maximum, is a center to the absolute value of the instantaneous rate of the standard deviation, Non-zero weak signal instantaneous phase of the nonlinear component absolute standard deviation, Non-zero weak signal instantaneous phase of the nonlinear component standard deviation, In the center is one of the non-weak signal of the absolute value of the instantaneous frequency standard deviation, a signal to one of the instantaneous frequency of the power spectral density of the maximum, According to 16QAM and QPSK signals XI axis projection in the different performance parameters raised.

提取信号七个基于瞬时信息的特征：零中心归一化瞬时幅度功率谱密度的最大值，零中心归一化瞬时幅度绝对值的标准偏差，零中心非弱信号段瞬时相位非线性分量绝对值标准偏差，零中心非弱信号段瞬时相位非线性分量标准偏差，零中心归一化的非弱信号段瞬时频率绝对值的标准偏差，一个信号段的归一化瞬时频率功率谱密度的最大值，根据信号 QPSK 和16QAM在 XI 轴投影的不同表现，提出特征参数。

The main work and the originality points of this dissertation could be concluded as the following parts:(1) To analyze systematically the mathematical model of LES of air flow in great space, under the case of isothermal and non-isothermal, as well as the combined action of buoyancy and strain. Some basic problems are studied about the LES application into airflow simulation of great space, such as boundary conditions, spatial difference scheme and time advancing scheme, time step etc., which creates the basis for the LES application to indoor airflow simulation.(2) Both the instantaneous and time averaged flow field of great space with multiple jets under isothermal and non-isothermal cases are explored with large eddy simulation method, and also discussed the dynamic characteristics and the law of fluidflow in the great space.(3) Based on the results of LES of the great space and the Fanger thermal comfort indexes, it is brought forward the concept of the series of dynamic thermal comfort evaluating indexes, which could be divided into thermal comfort index with time averaged properties PD, PPD, PMV, thermal comfort index with instantaneous properties IPD, IPPD, IPMV, and time averaged thermal comfort indexes TAPD, TAPPD, TAPMV, and transient situations time averaged thermal comfort indexes TTAPD, TTAPPD, TTAPMV. The differences among them and the calculation methods are discussed, and the four kinds of indexes are calculated with the thermal comfort index PD as an example.(4) Based on the LES results it is discussed the hot air stratification phenomena in air-conditioned buildings in the case with air supply and return registers on the ceiling and the case on the sidewall. The fundamentals of the hot air stratification are studied and the relations of estimating hot air stratification are brought forward.(5) With the advanced apparatus such as hot wire film anemometer IFA300 and laser particle field anemoscope, corresponding model test and site measurements have been done, which are compared with the simulation results and LES is proved a very promising method in air flow simulation indoor.

本文主要工作既创新点体现在以下几个方面：(1)系统分析了等温、非等温和考虑剪切力与浮升力综合作用的高大空间大涡模拟数学模型，并研究了高大空间大涡模拟在室内气流仿真应用中的一些基本问题，如边界条件、空间离散格式和时间推进格式、时间步长选择等问题，为大涡模拟在室内气流计算中的广泛应用打下了基础；(2)首次用大涡模拟方法研究了高雷诺数下高大空间多射流在等温、非等温情况下的瞬时流场和时均流场分布，并探讨了多射流流场的动态特性和流动规律；(3)基于大涡模拟的动态仿真结果和Fanger的热舒适指标，首次系统地提出了动态热舒适评价指标体系的概念：即基于时间平均参数的热舒适指标PD、PPD、PMV；基于瞬时参数的瞬时热指标IPD、IPPD、IPMV；基于时间平均热舒适指标TAPD、TAPPD、TAPMV；以及沿行动迹线的时间平均热舒适指标TTAPD、TTAPPD、TTAPMV，并分析了四类热舒适指标的差异性和计算方法，还以PD值为例对四类指标分别进行了计算；(4)基于数十种工况下空调房间大涡模拟的结果，研究了空调建筑上送上回和侧送侧回两种情况下热分层现象，并探讨了热分层的基本规律，首次提出了避免热分层现象的判断公式；(5)在暖通空调领域，首次使用IFA300热线风速仪、激光粒子速度场仪等先进设备，完成了与大涡模拟相对应的模型试验，并把实测结果与仿真结果进行了对比，说明LES在室内气流仿真方面是一种很有前景的方法。

By using this method, the angular frequency, amplitude, initial phase angle, decay constant of each component in transient voltage and/or current waveforms can be precisely extracted. Also, all other kinds of transient procedure can be analyzed by this method. Thirdly, a new definition of generalized instantaneous reactive power and generalized instantaneous reactive current in dq0 coordinates under any nonsinusoidal and unbalanced three-phase circuit is proposed for the first time. The detection and compensation method for different instantaneous reactive currents are also concerned.

本文首先提出了用于快速高精度频谱分析的一种改进快速傅立叶变换方法，该法具有速度快、精度高、抗混迭、不受采样定理约束、可以分析出谐次大于N／2的频谱系数等特点，可方便地应用于电力系统谐波分析及其它各类频谱分析；然后提出了基于非线性最小二乘优化法的电力系统暂态波形分析方法，可准确求出电力系统暂态电压、电流波形中各个分量的角频率、幅值、初相角及衰减常数，并可广泛应用于各类暂态过程波形分析。

This method undertakes comparative getting the area between the spare parts to equation of geometry of the face in model of CAD of different spare parts above all - surface contact relation and type, use amount coming back theory general face - the face expresses to be helix; relative to instantaneous motion next, the helix that goes up to many surface contact undertakes making operation,; of helix of the motion when making the opposite very short time between the spare parts is final, according to the spare parts abut concern plan and abut spare parts move relatively helix, undertook an analysis to assembling instantaneous of whole of the spare parts in the model to concern with drive movably, give out not between the method of calculation of helix of opposite instantaneous motion between photograph adjacent spare parts and them but the judgement method of drive sex.

该方法首先对不同零件CAD模型中面几何方程进行比较得到零件之间的面-面接触关系和类型，并应用旋量理论将面-面相对瞬时运动表示为螺旋；然后，对多个面接触上的螺旋进行交运算，生成零件之间的相对瞬时运动螺旋；最后，根据零件邻接关系图和邻接零件相对运动螺旋，对装配模型中零件整体瞬时可动性和驱动关系进行了分析，给出不相邻零件之间的相对瞬时运动螺旋计算方法和它们之间可驱动性的判定方法。

When the nonlinear layer which has weak nonlinearity is thin and far away from the seismic source which be low energy, compared with the corresponding results in linear antis, the medium nonlinearity produces abort 1/10~1/4 and 1/10~1/3 differences of instantaneous dominant frequency aid bandwidth. These instantaneous feature differences of seismic waves induced by the nonlinearity of media become weaker and weaker with the decrease of source energy. However, with the increase of the wave travel path within the mummer layer, the nonlinear accumulation effect could still keep such phenomena as the waveform distortion and instantaneous dominant frequency and bandwidth variations in records.

在本文给定的弱非线性介质中（非线性炽较薄且远离震源），在震源能量较低的情况下，介质的非线性效应会造成地震波瞬时主频和频宽相对于线性介质情况分别为1/10~1/14和1/10~1/3左右的变化量此外，随着入射波能量的下降，介质非线性所造成的地震波瞬时特征的变化量减小，但随着地震波在穿越非线性介质时路径的加长，非线性作用的累积效应使得波形畸变和频率分布特征的变化等现象得以维持。

The definition of instantaneous reactive power in sinusoidal circuit is still a pending problem and should be studied further. The authors consider that the theory of instantaneous power should be studied on the basis of the original definitions of instantaneous active and reactive power.

针对研究近一个世纪还没有解决的瞬时无功功率界定与定义的问题，该文认为应从原始瞬时有功功率、瞬时无功功率界定来研究瞬时功率理论。

The instantaneous power theory was employed to analyze the instantaneous power of the control winding and the control scheme for the DWIG system with diode bridge load was obtained. The component of the currents on the control-winding flux determines the instantaneous reactive power, and the component on the perpendicular direction of the flux decides the reactive power. The former one influences the DC voltage of the diode bridge on power winding and the latter one influences the DC voltage of the static excitation controller of control windings.

基于瞬时功率理论，推导出按控制绕组磁场定向时控制绕组的瞬时功率，在此基础上分析了带整流桥负载的定子双绕组感应电机发电系统在宽转速运行时的电压调节机理，即：控制绕组电流在控制绕组磁场及其法线上的分量，分别决定着发电系统功率绕组整流桥直流侧电压和控制绕组静止励磁控制器(static excitation controller，SEC)直流侧电压，据此提出宽转速运行时DWIG发电系统电压控制策略。

The frames with low and slowly changing average instantaneous frequencies were identified to be the periodic sonant segments and the frames with high average instantaneous frequencies were identified to be the surd segments based on the characteristics of the average instantaneous frequencies of IMFs derived from speech signals.

根据语言信号特定阶IMF平均瞬时频率的特征，将平均瞬时频率低且变化缓慢的语言帧作为周期性强的浊音段，而平均瞬时频率高的语言帧判别为清音段，组合处理后的结果最终得到语音段数据。

The instantaneous regurgitant velocity profiles obtained from the mitral heart valve prothesis test installed in a mock circulatory loop can be used to evaluate the regurgitation characteristic of the MHVP in vitro.

所获得的实验结果为评定二尖瓣替代物返流特性提供了可信的依据。标签激光多普勒测速声光扫描心瓣返流瞬态流速分布 LDA acousto-optic scanning instantaneous regurgitant velocity profiles

Numerical results show the collisional effects on some physics quantities, such as instantaneous voltages on the electrodes, instantaneous thicknesses of the electron sheathes, spatial distributions of the ion density and the electric field in the sheaths, and instantaneous voltage difference between two electrodes.

数值结果显示了碰撞效应对极板上鞘层的瞬时电压、瞬时电子鞘层厚度、鞘层内的离子密度和动能的空间分布以及两个极板上鞘层电压之差等物理量的影响。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。