查询词典 pi

2KD (PI=4. 5) special polypeptide-PI disappeared in the chlorosis area during the bleaching process.

但有一个56.2kD（PI=4.5）的特异蛋白在失绿区域的组织中消失，而在同一叶片的绿色区域组织中则可检测到该蛋白。

Study on design of the discrete state PI regulator and observers We extend the results of continuous system to discrete system in order to realize the state PI regulator by using computers.

离散状态PI调节器及估计器的设计研究将连续系统的有关结果推广到离散系统中，便于利用计算机进行计算和控制。

By analyzing the bode diagram of HAPF system and minimizing the capacity of HAPF, the paper presents a frequency dividing control method based on fuzzy-PI. In this mean generalized integrator is used for frequency dividing integral and fuzzy arithmetic is for adjusting PI coefficients timely. Compare with other kinds of control methods, the proposed one is more simple and easier realization.

该文由常用的并联型HAPF的结构特点分析出发，从容量和幅频特性2个方面探讨HAPF控制中进行有效分频的必要性，根据HAPF对控制方法的要求，文章提出一种基于广义积分的模糊自整定PI控制方法，即通过广义积分实施对周期量的分频积分，同时由模糊算法进行比例和积分系数的在线调整，从而有效实现对HAPF的分频控制。

ABSTRACT Aiming at problems of trans-vector controller in a vehicle-carried induction motor such as variable rotor and stator resistance following motor temperature, and their inductance varying with flux saturation degrees. Firstly, CSI and VSI are introduced, for CSI, it can hold the advantages both FOC and DTC using stator flux directional, PI parameter and simulation are also introduced. Secondly, equations of IM in the synchronous rotary frame and its static counterpart, as figuring in the saturation condition of magnetic field, are dealt in this paper and the simulation results are presented. Thereafter, the parameter designing of PI trans-vector controller is processed, which features the non-linear model. In practical realization, as neglecting the dynamical change of motor inductance, this paper employs online modification of inductance parameters, according to the flux saturation, then transforms the non-linear equations into linear ones, and so compacts the structure of controller. Thirdly, in view of the maximum torque output is extraordinary requisite when Electrical Vehicle start up, accelerate, and overtake, this paper issues the maximum torque when both inverter and battery capacity is corporeally definite. Fourthly, on-line differentiating and analyzing both rotor's time constants and its flux by using the expanding order reduction and discrete Kalman filter equation are fathomed, in order to realize high-performance trans-vector algorithm, and also the simulation results are presented. Fifthly, the close-loop regenerative brake system, when the EV's torque is set constant, is deduced; at the same time, unification of electric drive model and brake model is executed. Combined with maximum charge current demands, the mathematical model for online yielding torque as a demand.

本论文针对车载异步电机在矢量控制器所遇到的问题：定转子电阻随温度变化及随电机饱和程度变化的转子电感及定子电感而影响电机调速性能提出一套完整的解决方案：分析了电流型逆变器和电压型逆变器在实现矢量控制时控制器参数的计算，分析出对于电流型逆变器在采用定子磁场定向时，其性能同时具有矢量控制和直接转矩控制两者的优势，并对电压型逆变器在转子磁场定向下的模型进行了仿真研究；建立异步电机非线性模型，推导出考虑磁饱和时异步电机在同步旋转坐标系及静止坐标系下的方程，并做出了仿真结果，建立异步电机在非线性模型下的矢量控制调节器的PI参数设计，在实际应用中，若忽略电机电感的动态变化，可以根据当前的磁路饱和状态而在线修正电感参数，从而将非线性方程线性化，降低控制器的复杂度；考虑到电动汽车在起动和加速超车时需要电机有最大转矩输出，本文讨论在逆变器容量一定和电池供电能力有限的情况下电机最大转矩输出问题；推导了异步电机扩展降阶、离散卡尔曼滤波方程在线辨识转子时间常数和转子磁通，用于实现高性能的矢量控制算法，并给出了仿真结果；推导出了电动汽车恒转矩给定的闭环回馈制动系统，实现了电动控制模型和制动模型的统一，而且结合铅酸电池最大充电电流的要求，为制动转矩在线给定建立了数学模型；设计了基于双DSP系统的高性能矢量控制器软硬件框图，并以大量实验数据说明矢量控制在电动汽车应用的实际应用状况。

For the voltage space vector close loop control-based strategy, based on the proportional-plus-integral-based control scheme, a new control scheme composed of an adaptive resonant controller and a PI controller is proposed in the paper, by which the stator voltage waving is almost elimited, and a very well control performance is achieved for stator voltages, naturally, the softly cut-in control is realized.

针对基于空间电压矢量闭环控制的这一投切方案，在PI调节器控制的基础上提出了自适应谐振调节器与PI调节器并行控制的控制策略，有效抑制了定子电压幅值的波动，使定子电压具有较好的控制响应，进而实现了双馈风力发电机零电流切入电网的目的。

The PI in MCD high group was obviously higher than that in MCD low group.

MCD高计数组的PI值明显高于MCD低计数组的PI值，差异有非常显著性意义(P.01)。

In this case the PI was totally miscible with the amorphous PVP.

当PI含量＞40％，SEM显示有均匀分布的、棒状PI微晶存在。

The structure and process in PI is similarly to deduction in logic. But PI has much richer structures than predicate calculus. It is a complex of logic and psychology.

PI的结构与过程类似于逻辑中的演绎推理，但它的可取之处在于它可以提供比谓词逻辑更加丰富的结构形式，它是心理学与逻辑的综合。

The PI controller which is used widely in water level control of pressurizer in reactor control system usually leads dymanic overshoot and long setting time.

现代的反应堆稳压器的水位控制大都采用的是传统的PI调节器，对于这样一个非线性和时变性的复杂控制系统，PI调节器表现出来的常常是超调量大、调节时间长等并不理想的效果。

Methods 104 patients with chronic cerebral circulation insufficiency were randomly divided into two groups.in basis of routine therapy, patients in treatment group (n=56) were treated by yangxue qingnao granules,4 g,three times a day; patients in control group (n＝48) were treated by troxerutin, 3 pills a day.the course was 30 days in two groups.the indexes of hemorrheology and mca,aca,pca, va, ba and pi were observed before and after treatment.results there were significant differences between two groups in blood viscosity, plasma viscosity, mca,aca,pca,mca and pi after treatment (p.05).conclusion yangxue qingnao granules have definite effect on chronic cerebral circulation insufficiency, and decrease and hemorrheology in patients with ccci, relieve angiospasm and improve clinical symptoms.

将慢性脑供血不足患者104例随机分为2组。在常规治疗基础上治疗组56例加服养血清脑颗粒，每次4 g，每日3次口服。对照组48例在常规治疗基础上加服曲克芦丁，每次2片，每日3次口服。2组均30日为1个疗程。观察2组临床疗效，治疗前后血液流变学指标及大脑中动脉、大脑前动脉、大脑后动脉、左右椎动脉和基底动脉的搏动指数及阻力指数的变化。结果 2组治疗后全血黏度、血浆黏度，mca、aca、pca的pi及mca的ri及总有效率比较差异均有统计学意义(p＜0.05)。结论养血清脑颗粒治疗慢性脑供血不足疗效确切，能降低ccci患者的血液黏稠度及血液流变学指标，增加脑供血，缓解血管痉挛，改善临床症状，改善脑供血不足。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。