摘要：针对球磨机制粉系统的特点，介绍了一种多变量频域设计方法———反标架正规化（ＲＦＮ）设计方法的基本理论及设计步骤。将该方法应用于球磨机制粉系统，并利用ＣＡＤ软件包进行控制系统的设计。将该控制系统与采用解耦理论所设计的控制系统进行比较，从理论和仿真结果两方面说明了该方法应用于制粉控制系统设计的独有的优越性———系统具有较强的鲁棒性。

摘要：Magnetometric resistivity(MMR)method is a new way to detect dam *** coil sensor is generally used to collect data in geophysical exploration *** the characteristics of accurate vector data requirements and high sensitivity requirement,a three-component MMR air-core coil sensor is *** the analysis of sensor sensitivity and coil structure parameters,the coil structure and turn number are *** analyzing the noise source of the sensor,a suitable amplifier is selected to reduce the background noise of the *** the analysis of the three-component non-orthogonal angles,the parameters of the non-orthogonal angles of the coils are ***,a three-component MMR induction magnetic field sensor is *** volume of the sensor is controlled at 0.027 m *** background noise of X、Y and Z are 5.030435 nV/Hz@380 Hz and magnetic field sensitivities are 0.18995 pT/Hz@380 *** three channels have good consistency,and the three-component nonorthogonal angles correction error of three components is controlled within 0.2%.

摘要：Transient electromagnetic method(TEM)has been widely used in the field of medium and shallow underground detection due to its high detection efficiency and large detection ***,due to the long turn-off time of the transmitting current caused by the inductive characteristics of the transmitting coil,the early signals will be overwhelmed by primary *** the early signals contain most of shallow geological signals,it is necessary to reduce the long turn-off time to get shallow layer *** to lack of a reliable and effective clamping method for high-power transmission at present,we design a TEM transmitter fast turn-off circuit,combining self-resonant zero-voltage switching technology with the corresponding timing control circuit to solve this problem effectively.A transient electromagnetic transmitter based on self-resonant constant voltage clamping technology was fabricated to charge the clamping *** rated transmitting current of the transmitter is 20 A,and the turn-off time is continuously adjustable from 550-50μ***,the current drop process is approximately linear rather than exponential *** with the existing clamping methods,the proposed clamping method solves the problems that transient voltage suppressor(TVS)clamping cannot be used in high-power occasions and has a high failure *** also solves the problem of long pre-charge time in traditional capacitor clamping methods due to insufficient inductance of the small size transmitting *** proposed method can provide a reference for fast shutdown of large current.

摘要：维持球磨机在最佳工况下运行是火电厂重要的节能措施之一,但是这个问题在国内还未解决。本文分析了有中储仓式钢球磨煤机制粉系统的运行特性,给出了设计球磨机多变量模型算法控制的原则。提出了一种实用性很强的预测二步控制算法,并对这种算法用于球磨机控制进行了数字仿真,为用数字多变量控制技术解决球磨机自动化问题提供了一种研究方法。

摘要：目的研究桑黄黄酮最佳提取工艺。方法采用单因素和正交实验选出桑黄黄酮最佳提取工艺。结果确定桑黄黄酮最佳提取工艺参数为:温度80℃,提取8 h,料液比1∶20;乙醇质量分数70%。结论在此条件下黄酮的提取可达到(15.502 7±0.331 8)mg/g。

摘要：钢筋混凝土桥梁暴露在恶劣工作环境下常常受到裂纹损伤威胁,及时有效地检测到混泥土梁的微裂纹以及识别梁的损伤状况是保证桥梁安全作业的重要基础。针对目前采用全波形声发射仪采集声信号受到噪声污染而影响探伤精度的问题,提出了基于神经网络的非线性独立分量分析(ICA)与维格纳分布(WVD)的损伤声发射信号特征提取与识别的新方法。通过RBF网络估计混入声信号中的非线性噪声成分,利用ICA算法分离出真实的梁损伤声信号,消除噪声干扰,并应用WVD分析分离信号的时频谱分布,提取信号特征频率处的能量特征作为识别损伤状态的有效参数。三点弯曲加载试验结果表明,非线性ICA能够有效抑制噪声导致的声信号频率漂移,得到信号可靠的关键特征,提高梁裂纹损伤的识别精度,且结果比不进行去噪处理提高了9%。

摘要：Transient electromagnetic method (TEM),as a non-seismic geophysical exploration mainstream electromagnetic method,is widely used in oil,gas,mineral and other underground resources exploration areas. The coil sensor is generally used to collect data. In view of the problems of incomplete information of the abnormal body and the data loss in the existing TEM single-component coil sensor,a three-component TEM coil sensor is designed. By analyzing the relationship between sensor sensitivity and coil structure parameters,the coil structure and turns are designed. By analyzing the frequency response characteristics of the TEM magnetic field sensor,the signal distortion is reduced by using the under-damped matching mode. By analyzing the distribution of various noise sources of the magnetic sensor,the appropriate amplifier is selected to reduce the background noise. Finally,a three-component TEM induction magnetic field sensor is designed. The weight of the sensor is controlled at 3.2 kg and the working frequency is 10 mHz-10 kHz. The background noises of X and Y components probably keep in 1.5×10^-8 V/ Hz and sensitivities are 8.4 and 9.8 nT/s,respectively,the background noise of vertical component is 2.1× 10^-7 V/ Hz and sensitivity is 18.5 nT/s. Compared with the existing single-component TEM receiving magnetic field sensor,the designed sensor realizes the signal acquisition of three components. Without too much increase in volume and total weight,it improves the sensitivity of the sensor and reduces the background noise,thus the signal-to-noise ratio (SNR) of the signal is improved.

摘要：我们从1978年3月～1994年5月采用胶皮兜固定自动复位[1]和蛙式铝板支架固定[2]及七种不同手术[3]治疗先天性髋关节脱位2 857例,共计3 491个髋,虽然取得了较好的效果,但仍有一部分患儿遗留下不同程度的病残.于是,在总结分析了每种治疗方法成败原因的基础上,根据先天性髋关节脱位的病理变化,对失去闭合复位时机的患儿设计了一种三联术,即切开复位、股骨短缩旋转截骨及髋臼成形术,共治疗385例,计468个髋,无一例死亡、感染或股骨头坏死,现介绍如下.

摘要：本文针对"连续与离散控制系统"课程的特点,利用Matlab的GUI工具设计了倒立摆控制教学辅助实例,能够对PID算法、线性二次调节器(Linear Quadratic Regulator)算法、H∞算法的参数进行设置,实现单级倒立摆的反馈控制仿真。该教学实例的应用加深了学生对倒立摆控制系统的认识,有助于理论知识的理解,提升学习兴趣,提高教学效果。

摘要：发育性髋脱位(DDH)是儿童先天性骨关节畸形的常见病之一,发病率在我国约占3.8‰.由于其病因及其病理改变的复杂,且随着年龄的增长日趋严重复杂,国内外学者已发明了多种的手术方式,尽管各类手术在治疗后均有较高的成功率,但仍然有术后再脱位的发生.再次手术治疗增加了股骨头坏死、关节僵硬等并发症,且影响远期疗效故应积极预防.我院应用自己设计的联合术式治疗DDH术后再脱位20例,取得了满意的效果.现探讨再脱位的原因,并提出相应的预防措施报道如下.