1.8 V千兆以太网接收器模拟前端预均衡电路

介绍了一种用于1.8 V电源电压下的千兆以太网接收器的模拟前端预均衡电路。电路分为三个部分:预处理电路、基带漂移补偿电路和可变增益放大电路,主要实现回波消除、基带漂移补偿和电路增益自动控制等功能。为了与百兆模式兼容,提出了一种预处理电路。仿真结果表明,该电路可以很好地实现回波消除的功能,能够对由于基带漂移引起的信号失真给以补偿,可以提供16级不同的增益,并进行频率补偿。电路采用0.18μm标准CMOS工艺实现。     

延长鄂式破碎机破碎板使用寿命的方法

鄂式破碎机工作时,破碎板直接与物料接触,承受着巨大的破碎力和物料的摩擦作用,破碎板的使用寿命直接关系到鄂式破碎机的工作效率和生产成本。从设计、选材、组装、使用过程中的改进等方面,论述了延长鄂式破碎机破碎板使用寿命的方法。     

半合成发动机油基础油调配的仿真研究

采用矿物油、聚α-烯烃、多元醇酯和高压加氢BS光亮油调配半合成发动机油基础油,并测定不同配比下基础油的油膜强度、摩擦系数和粘度指数,通过双隐层BP神经网络对基础油调配进行仿真研究,建立了半合成发动机油基础油调配配方优化模型,经过优化训练后,最终得出综合性能优良的配方组合。按49.9957∶4.3693∶42.4578∶3.1772的配比调配基础油,可以使基础油的油膜强度、摩擦系数和粘度指数分别达到56 kg,0.065和112,经实验后仿真结果与实验结果(56 kg;0.065598;112)极其吻合。     

温度采集仪调理电路的isp实现技术

介绍温度采集仪调理电路的结构及工作原理,简单介绍在系统可编程模拟器件ispPAC10的基本结构,并借助于PAC Designer软件详细描述ispPAC10实现温度采集仪数据放大器具体方法和步骤。与传统的模拟电路设计方法相比,运用isp技术实现的温度采集仪调理电路具有简洁可靠、开发周期短等特点。     

一类连续模糊动态系统控制方法在Furuta摆中的应用

为了研究Furuta摆在倒立点附近的稳定控制问题，采用基于T-S模糊模型的一类连续模糊动态系统控制方法，首次进行Furuta摆的模糊状态空间建模，并采用模糊切换的思想，设计了Furuta摆在倒立点附近的稳定控制器，进而分析了系统稳定性。与已有的方法相比，该方法的优点是稳定区域大、调节时间短。数字仿真结果验证了方法的有效性。     

新产品研发是建陶企业可持续发展的核心

新世纪我国建陶企业在整个国民经济的带动下将进一步发展，入世后经济全球化的市场竞争格局，建陶企业只有走新产口研发之路，严格企业管理，才会在日趋激烈的市场竞争中得以生存和可持续发展。     

AlGaAs／GaAs HBT集成电路的CAD

介绍了一套用于ＡｌＧａＡｓ／ＧａＡｓＨＢＴ集成电路的ＣＡＤ软件，它可完成ＨＢＴ的器件模拟、模型参数提取及电路模拟。应用该软件对ＨＢＴ运算放大器进行了模拟，为电路的研制提供了依据。     

CMV colitis masquerading as colon cancer--an unusual presentation of acquired immunodeficiency syndrome

To determine whether there is any correlation between sudden decrease in barometric pressure and onset of labor, a non-experimental, retrospective study at a 948-bed tertiary care hospital was done. Pregnant patients of 36 weeks gestation or more who presented with spontaneous onset of labor during the 48 hours surrounding the 12 occurrences of significant drop in barometric pressure in 1992 were included in the study. Significantly more occurrences of onset of labor were identified in the 24 hours after a drop in barometric pressure than were identified in the 24 hours prior to the drop in barometric pressure (P < 0.05). Therefore, the overall number of labor onsets increased in the 24 hours following a significant drop in barometric pressure.     

Evaluating generalized predictive control for a brushless DC drive

This paper proposes a new control approach for a brushless DC motor drive using the generalized predictive control (GPC) algorithm. Based on the same least-squares framework as in the controller design, we further develop the method to design an observer. The GPC algorithm uses the receding horizon approach whereby the control signals are determined by minimizing a quadratic cost function. Our study shows that the rise time and settling time of the servo system have an approximate linear relationship with the prediction horizon. Thus, it is used to tune the controller of the drive. Moreover, the control weighting factor can be used to smooth the controller output. The proposed algorithm has been implemented using a digital signal processor (DSP) and tested in real time with a prototype system. The performance and robustness of the algorithms have been evaluated both in simulation and experiment. The results show that the drive performs reasonably well despite load changes and step changes in the position setpoint. Furthermore, it is fairly robust against motor parameters change     

Extended application of the complex source-point theory

In this paper, the complex source-point theory used for a symmetric concave spherical resonator is extended to an asymmetric concave spherical resonator. Thus, the formulae for the field distribution of the asymmetric spherical resonator can be easily deduced from the formulae for the field distribution of the symmetric resonator, thereby the application range of the complex source-point theory is enlarged and a convenient method is provided for the field analysis of an arbitrary spherical resonator.