频率曲线

Absorption curve of four micro-perforated panel is the best in three different structure. But its performance is close to three layer micro-perforated panel.

优化后的四层微穿孔板结构在整个频率内的吸声系数曲线最为饱满，但是与三层结构相比，吸声性能提高不多。

The additional error in measuring the slope of C~(-2)- V curve is further discussed.

在Q表上用四种小讯号频率测量了TTL电路和某些线性电路外延片的C~(-2)-V曲线。

The foundation of this system provides a good reference to promote the standardization and intelligence of the overhaul and maintenance of vacuum switches. This paper develops a special HF pulse power supply for internal pressure estimation, which achieves the output of HF-HV sinusoidal pulse wave whose frequency and amplitude can be modified respectively, and meets the design requirements according to the results of Simulink simulation and practical experiments. With the help of AT89S52, this paper designs an I~2C serial bus based signal detection system for peak value signal acquisition of HF pulse currents, which communicates with the upper computer by asynchronous serial communication for uploading the data. In the upper computer, a human computer interface is developed by Matlab software, whose functions are to do some computation and graphic display, such as calibrating the relation curve of vacuum degree and peak value of HF pulse currents, vacuum degree computation, and vacuum lifetime evaluation analysis basing on grey forecasting model as well as making relative suggestions.

本文研制了用于真空度检测的高频脉冲电源，通过Simulink仿真和试验检验其满足设计要求，实现了电压幅值和频率独立可调的正弦波高频高压脉冲输出；利用以AT89S52为核心基于I~2C串行总线的信号检测系统实现高频脉冲电流峰值信号的采集，通过异步串行通信实现单片机与计算机之间的数据通信，将检测数据传至上位机；在上位机利用Matlab开发人机交互界面，实现相关数据处理和图形显示，包括真空度——高频脉冲电流峰值关系曲线标定、真空度数值计算、基于灰色预测模型的真空寿命评估分析和提出相应决策建议。

In order to make the microstrip equalizer matchs the given attenuation curve respectively ,it should be attenuation adjustable and quality factor adjustable besides frequency adjustable.

摘要为了使微带均衡器满足衰减特性与给定的误差曲线逐点拟和的要求，就必须使其频率可调、衰减可调、品质因数可调。

Methods Pure tone audiometry,SISI,ABLB and white-noise masking effect(Langenbeck's methods) audiometries were performed in 30 patients (44 ears) with sensorineural hearing loss with BOSCH audiometer made in Germany.

用德国产BOSCH听力计对30例(44耳)感音神经性听力损失患者作纯音测试和阈上测听(包括Langenbeck，SISI和ABLB试验)，比较三种试验相对于三种听力曲线及1，2和4 kHz三频率的阳性结果。

Simulations based on finite integration method are carried out in a wide frequency range for a balanced feeding finite wide-angle biconical antenna and many results including input impedance and far fields are obtained.

利用基于有限积分法的电磁场仿真技术对平衡馈电的有限长宽角双锥天线作了计算，得到了天线在很宽频带内输入阻抗、远区辐射场与频率的关系曲线。

According to the standard and request of mechanical structures for electronic equipment tests, the finite element model of the electronic equipment cabinet was built by using the software of finite element analysis-ANSYS and simulated the tests of random vibrations by loading and calculating. The 3-D isopleths graph of deformation and stress of the cabinet was obtained. It could confirm the maximum of deformation and stress of the cabinet and probability of occurrence. Through more analysis of the frequency response curve reflected directly and clearly the deformation of the cabinet within the particular seismic frequency.

根据电子设备机械结构随机振动试验的标准和要求，采用有限元分析软件ANSYS建立电子设备机柜结构的有限元模型，通过加载求解对其进行随机振动试验的数值模拟，得到机柜有限元模型的三维变形和应力等值线图，进而确定机柜承受应力和变形的最大值及发生概率；通过对频率响应曲线的进一步分析，可以直观明了地反映出机柜承受一定频率范围地震下的变形情况。

In order to explore the relationship between the echolocation call or signal of leaf-nosed bats and frequency tuning of inferior collicular neurons, the echolocation calls of the leaf-nosed bats were recorded using bat detector and frequency tuning curves of inferior collicular neurons were obtained by extracellular recording.

采用超声监测仪录制超声信号和细胞外电生理记录下丘神经元的频率调谐曲线(frequency tuning curves， FTCs)的方法，探讨了大蹄蝠回声定位信号与下丘(inferior colliculus， IC)神经元频率调谐之间的相关性。

Then, according to HVS, the vibrant valve is designed. On the basis of coupling analysis and simulation study of the vibrant valve and the release valve, the simulation curve about the fluid pressure variation in the pile-driving oil pipe is obtained, by which the relationships among the highest pressure value, average pressure value and the pile-driving frequency are obtained.

然后根据液压振动系统设计了振动开关阀，并重点对液压振动系统中的溢流阀和振动开关阀进行了耦合分析和仿真研究，得出压桩油路中流体压力变化的模拟曲线，并根据模拟曲线分析得出流体压力的最高压力值、平均压力值和压桩频率间的相互关系。

Then the time-temperature shift principle is used to translate the relationships from three dimensions to two dimensions, so master curves are obtained regarding dynamic modules changing along with the frequency over 15 amount levels.

利用时温等效原理，将频率扫描试验得到的三维关系进行温－频转换，获得了跨越15个数量级的动态模量随频率变化的二维全频主曲线。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。