Possible effects of site isolation in antimony oxide-modified vanadia/titania catalysts for selective oxidation of o-xylene

Titania-supported vanadia catalysts were modified by addition of antimony oxide for application in o-xylene selective oxidation to phthalic anhydride. It was shown that active and selective catalysts can be prepared by ball-milling mixtures of powders of TiO₂, V₂O₅and Sb₂O₃followed by calcination. X-ray photoelectron spectroscopy proves the formation of highly dispersed overlayers of vanadium oxide and antimony oxide, in which V⁵⁺is partially reduced to lower oxidation states and Sb³⁺is partially oxidized to Sb⁵⁺. Antimony oxide segregated into the outermost surface layers. It is therefore inferred that the presence of the antimony oxide modifier spatially separates V–O species and leads to site isolation which may be responsible for the positive effect of the modifier for the catalyst's selectivity.     

Isolation of Whole-plant Multiple Oscillations via Non-negative Spectral Decompositio

Constrained spectral non-negative matrix factorization（NMF）analysis of perturbed oscillatory process control loop variable data is performed for the isolation of multiple plant-wide oscillatory sources.The technique is described and demonstrated by analyzing data from both simulated and real plant data of a chemical process plant. Results show that the proposed approach can map multiple oscillatory sources onto the most appropriate control loops,and has superior performance in terms of reconstruction accuracy and intuitive understanding compared with spectral independent component analysis（ICA）.     

浅谈DCS控制系统的供电技术

主要对自动控制系统中采用的电源供电方式进行了简单阐述,并分析了电源系统的隔离技术和冗余电源设计技术的应用,从而达到抗干扰的目的。     

Enantiomer-based specificity in pheromone communication by two sympatricGnathoirichus species (Coleoptera: Scolytidae)

The aggregation pheromone ofGnathotrichus retusus was isolated and identified as (S)-(+)-sulcatol (6-methyl-5-hepten-2-ol). In laboratory and field experiments,G. retusus responded to (S)-(+)-sulcatol, but not to (±)-sulcatol, which was attractive to the sympatric species,G. sulcatus. G. sulcatus did not respond to optically pure (S)-(+)-sulcatol, but began to respond when 1% (R)-(–)-sulcatol was present in an enantiomeric mixture.Research supported by the National Science Foundation, U.S.A. (Grant BMS-74-13643), and the Natural Sciences and Engineering Research Council of Canada (Co-op grant A0243 and Operating Grant A3881 and A3785).     

Differential geometry based active fault tolerant control for aircraft

This work shows how to use a differential geometry tool to design a novel nonlinear active fault tolerant flight control system for aircraft. The proposed control scheme consists of two main subsystems: a controller, which is designed for the nominal plant, and a fault detection and diagnosis module, which provides fault estimation. A further feedback loop exploits the fault estimation to accommodate faults affecting the system. The estimate convergence and the stability of the active fault tolerant flight controller are theoretically proved. Finally, high fidelity simulations show the effectiveness of the scheme.     

核电站安全级DCS隔离设计研究

在核电站安全级DCS设计中,为提高系统的可靠性,需保证安全级电气设备和电路之间的有效隔离,为了实现电气设备和电路的隔离,核安全相关法规标准提出了实体分隔、电气隔离等设计手段。本文通过对核电站安全级DCS隔离相关法规标准的分析,得出了电气设备和电路隔离的设计要求,提出了设计过程中应采取的方法和措施,并在此基础上给出了具体的实体分隔和电气隔离工程实现方案。该方案的工程实施结果可实现安全级DCS电气设备和电路的独立性要求,有效提高系统的可靠性,为系统的稳定运行提供重要保证和支持。     

CDMA干扰对GSM系统的影响及消除方式

本文主要研究CDMA系统对GSM系统的上行干扰,通过实验以及理论计算分析CDMA干扰对GSM系统的影响,并结合天线隔离度分析两系统之间的安全距离.     

Invariant‐set‐based fault diagnosis in Lure systems

In this paper, we present an invariant‐set‐based method for actuator and sensor fault detection and isolation in Lure systems. The Lure plant is controlled by an observer‐based feedback tracking controller, designed for the nominal (fault‐free) system. Suitable residual signals are constructed from measurable system outputs and estimates associated with the nominal observer. Faults are diagnosed by online contrasting the residual signal trajectories against sets of values that the residuals are shown to attain under healthy or faulty operation. These values are obtained via set‐invariance analysis of the system closed‐loop trajectories. Copyright © 2013 John Wiley & Sons, Ltd.     

几株纤维素酶产生菌的分离鉴定及其产酶能力

从枯枝、秸秆、土壤中分离出35株产纤维素酶菌株。以酶活值作为复筛标准,筛选出5株产羧甲基纤维素酶和滤纸酶活力相对较高的菌株,分别为柱隔孢霉（Ramularia NS1）、康氏木霉（Trichoderma koningii NS2）、灰绿青霉（Penicillium glaucum NS3）、白腐菌（White-rot fungi NS4）和绿色木霉（T.viride Persex Fx NS5）。经？瓶发酵和酶活检测,其羧甲基纤维素酶活（CMC酶活）分别为297.97 IU/mL,300.11 IU/mL,154.83 IU/mL,146.68 IU/mL,308.14 IU/mL;滤纸酶活（FPA酶活）分别为6.56 IU/mL,5.63 IU/mL,4.29 IU/mL,9.63 IU/mL,8.02 IU/mL。其中绿色木霉（T.viride PersexFxNS5）在发酵条件：麸皮：CMC-Na（1：1）各6 g/L,硫酸铵4 g/L,发酵温度30℃,发酵时间3 d,发酵液CMC酶活和滤纸酶活分别达到352.11 IU/mL和13.96 IU/mL,比初筛酶活分别提高14.26%和74.06%。     

非线性系统传感器偏差的自适应故障检测与分离方法

针对一类具有模型不确定性且状态部分可测的非线性系统,提出了一种基于鲁棒自适应技术的传感器偏差故障检测与分离方法。所提出的故障检测与分离方法是由一个故障检测估计器和一组故障分离估计器完成的,其中每一个故障分离估计器对应一种类型的传感器偏差故障。对于某一故障分离估计器如果它的的输出估计误差中至少一项的绝对值超过相应的自适应阈值,则这个故障发生的可能性被排除,即可分离故障。在系统存在模型不确定性和状态部分可测的情况下,应用自适应技术来估计未知的传感器偏差故障并分析了故障分离器的稳定性。仿真算例证明了所提出的鲁棒自适应故障检测与分离方法的有效性。