时基控制

In our research on study chemical reaction of active methylene compounds and brom-acetophenone. Because of brom-acetophenone is compound that contain carbonyl and halogen ,which will take place electrophilic substitution and nucleophilic addition. When active methylene compounds are ethyl acetoacetate and β-diketone, controlling reaction condition, we have found that mono-substitution's production and di-substitution's. production is isolated; active methylene compounds are acetoacetanilide and acetoacetanilide derivate, pyrrolidin-2-one derivants were obtained by substitution and close-ring reaction .but there is no report about it.

本文是让活泼亚甲基类化合物与溴代苯乙酮发生化学反应，由于溴代苯乙酮是含有羰基的卤代烃结构，它可以发生亲电取代和亲核加成反应，当活泼亚甲基类化合物为乙酰乙酸乙酯和β-二酮时，控制反应条件可以发生单取代和双取代两种产物；当活泼亚甲基类化合物为乙酰乙酰芳胺类化合物来反应时，溴代苯乙酮中的羰基与氨基会发生分子内的关环反应生成吡咯烷-2-酮衍生物，这在以前的研究中是没有发现的。

The flux hysteresis controller was ignored in the constant torque region and an improved method was proposed to make the estimation of torque easier.The proper stator voltage space vector was selected based on the output of the torque hysteresis controller and the sector which the current rotor flux locates in.

摘 要：针对无刷直流电机直接转矩控制中磁链观测困难、控制复杂等问题，提出了一种应用于无刷直流电机二二导通方式下的新型直接转矩控制方法：在电机基频以下调速时，略去了常规的磁链观测控制环节，改进了转矩计算方法，通过转矩滞环控制选择所施加的空间电压矢量。

A new brushless DC motor DTC scheme was studied to solve those problems associated with direct torque controlof brushless DC motor,such as difficulty to control flux and complexity to estimate torque.The flux hysteresis controller was ignored in the constant torque region and an improved method was proposed to make the estimation of torque easier.The proper stator voltage space vector was selected based on the output of the torque hysteresis controller and the sector which the current rotor flux locates in.

摘 要：针对无刷直流电机直接转矩控制中磁链观测困难、控制复杂等问题，提出了一种应用于无刷直流电机二二导通方式下的新型直接转矩控制方法：在电机基频以下调速时，略去了常规的磁链观测控制环节，改进了转矩计算方法，通过转矩滞环控制选择所施加的空间电压矢量。

Use the time-based gating singal created by time-delay to control the strobe. Compute the frequency with the help of the number of pulses recorded by the counter in specific time, then screen the result on the LCD.

利用延时产生的时基门控信号来控制闸门，通过在单位时间内计数器记录下的脉冲个数计算出输入信号的频率，最终送入LED中显示。

The chemical structure of the product was characterized by means of the melting point and IR. The results show that tetraethylammonium bromide which was used as a phase transfer catalyst in this reaction had optimization effect on the interfacial diffusive reaction of BTC and PNP. Higher concentration of sodium hydroxide, lower temperature and a higher dosage of BTC produced a small amount of 4-nitrophenyl chloroformate, while lower concentration of sodium hydroxide and a lower dosage of BTC made reaction incomplete, which affected the yield.

结果表明，在碳酸二（4-硝基苯基）酯合成中使用的相转移催化剂四乙基溴化铵对受界面扩散控制的BTC气与对硝基酚钠反应有良好的相转移催化效果；氢氧化钠质量分数较低时，酚钠盐向溶有BTC的油相扩散速度较小，较高时会产生氯甲酸对硝基苯酯；温度较低、BTC量较高时，会产生少量氯甲酸对硝基苯酯，BTC用量较低会使反应不完全，这些都影响着收率。

Firstly, this paper based upon coordinate transformation in vector space, the resolution principles of ship's swinging in three rotative axes of a hull – mounted array sonar are developed. The analytical results are used as the rules to control and stabilize the attitude of the array sonar so as to isolate the swinging of the ship.

本文首先根据矢量空间坐标变换的原理，分析了船舶摇摆运动在声纳基阵转动轴上的分解原理，得出了控制和稳定声纳基阵姿态不受船舶摇摆影响时所需的控制规律。

Application of PMAC time-base control in the NC machining of noncircular section parts;2. This system solved the problem about the motion s devolving, it is the applying of function of PMAC on accurate and time-base controlling that ensured the synchronization of motion.

为解决感应加热过程中传送运动系统的运动交接难的问题，开发了一种以PMAC运动控制器为核心的运动控制系统，利用PMAC卡运动控制的精确性和时基控制的同步性解决了控制运动的交接问题，经试验证明所开发的系统可以达到控制要求。

Firstly, a new design method of cam profile has been developed by using finite terms of Fourier Series in the cycle of cam angle as the basic equation of cam profile, so the difficulty of base circle wave existing in the method of resonant cam design can be eliminated. On the other hand, the method proceeds from the acceleration of cam profile, which makes the acceleration not only smooth and continuous, but also easy to be controlled, and the cam profile with good performance can easily be acquired.

此方法用以凸轮包角为周期的富立叶级数有限项作为凸轮型线的基函数，可以免去谐波凸轮设计时控制基圆波动的困难；此方法又是从凸轮型线的加速度曲线入手进行设计，使型线加速度不但光滑、连续，而且形状容易控制，便于设计出动力性能优良的凸轮型线。

Base played a crucial role in this reaction: in the Pd2/L1 catalyzed α-arylation of ethyl malonate, K3PO4 is the base of choice; in the α-arylation of ethyl acetoacetate, K2CO3 is the most effective base.

在这类催化反应中，碱的选择具有重要的影响：以K3PO4为碱， Pd2/L1催化体系在丙二酸二乙酯的α-芳基化中，富电子溴代芳烃显示较好的活性； Pd2/L1催化的乙酰乙酸乙酯α-芳基化时，以 K2CO3为碱，催化体系显示较好的活性，这个催化体系可控制反应得到α-芳基乙酰乙酸乙酯，而不是脱乙酰基的产物。

The results show that the zinc coating is eroded mostly, and some red rust and black rust appear on the substrate in the environment of oxygen supplied intermittently.

结果表明：在间歇通O2的情况下，锌层大部分被腐蚀，而且在基体上有一些红锈和黑锈产生，镀锌板表面的腐蚀产物呈现着不均匀的针状物；而在间歇通N2时，镀锌板的锌层脱落面积较少，基体上没有产生红锈，腐蚀产物呈大块状；在间歇通O2和通N2的情况下，镀锌板的腐蚀速率先增后降，在200 h时，前者的腐蚀质量损失速率是后者的2倍左右；镀锌板附着库尔勒泥浆时的腐蚀过程受氧去极化过程控制。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失