Optimal moving average filter with application to self-tuning type control against deterministic disturbances

An optimal moving average (OMA) filter for a linear stochastic controlled plant is developed from the viewpoint of the internal model of the deterministic disturbance. The OMA filter enables the minimum-variance self-tuning control not only to overcome effectively various kinds of deterministic disturbances modelled by the linear homogeneous difference equation (such as stepwise and sinusoidal disturbances), but also to depress greatly the amplification of random noise in the control system. Thus, both the precision of parameter estimation and the quality of control can be improved, especially in the cases of strong coloured noise. The basic idea of the OMA filter is also extended to the multivariable system case. Several numerical examples have shown the effectiveness of the OMA filter in different cases. Some remarks on the use of the OMA in self-tuning control are also presented.     

Terahertz Transmission Properties of Split Ring Resonator Arrays

The transmission properties of double-ring split ring resonator(SRR) arrays and closed ring resonator arrays are measured using terahertz(THz) time-domain spectroscopy. This technique allows for the simultaneous measurement of the amplitude and phase of the transmission coefficient as a function of frequency. The ability to directly measure the phase spectrum is expected to be important in characterizing potential negative index media. In the employed experimental geometry, THz pulses are normally incident ...     

无黏结剂H-ZSM-5沸石催化剂的改性及其催化稀乙醇脱水

以X射线粉末衍射(XRD)、27Al固体核磁共振(MAS NMR)、低温氮吸附、NH3-TPD、吡啶吸附原位红外光谱(in situ IR)等手段表征酸处理、水蒸气处理及其混合处理改性的无黏结剂H-ZSM-5沸石催化剂,考察不同改性方法对其组成、晶体结构、孔结构以及表面酸性质的影响,揭示了水蒸气处理对催化剂物性的强烈调变作用.对比改性前后上述催化剂用于50%稀乙醇脱水制乙烯催化反应中所得转化率和乙烯选择性,发现水蒸气.HCI处理相结合改性的催化剂活性最佳.     

严重脓毒症患者动脉乳酸动态监测的临床意义

目的探讨严重脓毒症患者动脉乳酸及乳酸清除率的变化与预后的关系。方法对我院收治的57例严重脓毒症患者测定入院和入院6h动脉乳酸,计算6h乳酸清除率。根据24h内最差生命体征、生化指标、年龄及是否手术计算APACHEⅡ。据患者预后分为存活组和死亡组,比较2组动脉乳酸及6h乳酸清除率;绘制动脉乳酸及其清除率、APACHEⅡ的ROC曲线,比较其判断预后的价值;据APACHEⅡ分为≤20分组及>20分组,用独立样本t检验比较2组动脉乳酸及乳酸清除率;用Pearson相关分析APACHEⅡ与动脉乳酸及乳酸清除率相关性;应用Logistic回归分析影响严重脓毒症患者预后的独立危险因素。结果死亡组动脉乳酸(10.74±2.29)明显高于存活组(5.24±2.89),死亡组患者乳酸清除率(10.69±3.72)明显低于存活组(34.00±13.68),有统计学差异(P<0.01);应用APACHEⅡ判断严重脓毒症患者预后的ROC曲线下面积AUC为0.869,6h动脉乳酸AUC为0.951,6h动脉乳酸清除率AUC为0.942,差异有统计学意义(P<0.000);APACHEⅡ>20分组较≤20分组动脉乳酸升高,6h动脉乳酸清除...     

离子液体修饰超顺磁性纳米颗粒用于青霉素G酰化酶固定化(英文)

Functionalized ionic liquids containing ethyoxyl groups were synthesized and immobilized on magnetic silica nanoparticles(MSNP) prepared by two steps,i.e.,Fe3O4 synthesis and silica shell growth on the surface.This magnetic nanoparticle supported ionic liquid(MNP-IL) were applied in the immobilization of penicillin G acylase(PGA).The MSNPs and MNP-ILs were characterized by the means of Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and vibrating sample magnetometer(VSM).The results showed that the average size of magnetic Fe3O4 nanoparticles and MSNPs were ~10 and ~90 nm,respectively.The saturation magnetizations of magnetic Fe3O4 nanoparticles and MNP-ILs were 63.7 and 26.9 A?m2?kg?1,respectively.The MNP-IL was successfully applied in the immobilization of PGA.The maximum amount of loaded enzyme was about 209 mg?g?1(based on carrier),and the highest enzyme activity of immobilized PGA(based on ImPGA) was 261 U?g?1.Both the amount of loaded enzyme and the activity of ImPGA are at the same level of or higher than that in previous reports.After 10 consecutive operations,ImPGA still main-tained 62% of its initial activity,indicating the good recovery property of ImPGA activity.The ionic liquid modified magnetic particles integrate the magnetic properties of Fe3O4 and the structure-tunable properties of ionic liquids,and have extensive potential uses in protein immobilization and magnetic bioseparation.This work may open up a novel strategy to immobilize proteins by ionic liquids.     

浅论住宅工程项目材料成本的管理与控制

针对住宅项目的材料成本占建筑成本比重大的特点，分析了目前住宅项目材料成本管理的现状和存在的问题，提出了材料成本管理的原则，指出只有从材料的“质、量、价”三个方面进行成本控制，才能提高企业的经济效益和竞争能力。     

桂西北大石山区地头水柜集雨灌溉工程发展探讨

介绍桂西北大石山区基本情况，桂西北地头水柜试点情况，指出地头水柜试点工程存在的问题，并提出有关建议。     

大型高压蒸汽阀流量特性的数值模拟

为提高动态工况下某蒸汽阀流量的控制精度,实现开度-流量的精确控制设计,采用CFD方法对其内部流场进行了数值模拟研究,以获取流量系数-开度的关系式。首先利用水介质的计算结果与前期试验结果进行比较,对有限元模型进行了验证。此后,采用蒸汽对不同开度及压差下蒸汽阀内部的流场进行了模拟计算,借鉴节流装置可压缩流体的流量方程式,获得了蒸汽阀流量特性曲线及关系式,并将其结果与理想气体得到的流量系数结果进行了对比分析,结果表明利用理想气体代替蒸汽进行流量特性研究具有一定的合理性。     

棒状纳米ZnO薄膜晶体管效应的测定

分别采用水热法和微乳法制得了两种直径为10～40nm和60～70nm的棒状纳米ZnO材料;然后将制得的纳米材料乙醇溶液旋涂到石英基片上,将其中一部分旋涂膜进行煅烧,最后将经过煅烧和未经过煅烧的旋涂膜基片采用top-contact的方法镀上电极制成薄膜晶体管进行场效应的测定;实验表明:对于直径不同和同种样品旋涂膜经不同处理的场效应参数存在明显的差异,特别是电子迁移率,直径较大的未经煅烧的纳米ZnO旋涂膜的电子迁移率可以达到μ=156cm2V-1s-1。     

玻璃配合料中B2O3、Fe2O3检测方法的改进

玻璃配合料中B2O3和Fe2O3含量的稳定性是决定玻璃纤维生产稳定与否的关键因素,而现今使用的传统的配合料中B2O3、Fe2O3检测方法都较繁冗,不能快速准确地指导生产。本文介绍了配合料中B2O3、Fe2O3的新的检测方法,此检测方法具有简单、快捷、误差小的优点。