Effect of dopant concentration on photocatalytic activity of TiO2 film doped by Mn non-uniformly

The thin films of TiO2 doped by Mn non-uniformly were prepared by sol-gel method under process control. In our preceding study, we investigated in detail, the effect of doping mode on the photocatalytic activity of TiO2 films showing that Mn non-uniform doping can greatly enhance the activity. In this study we looked at the effect of doping concentration on the photocatalytic activity of the TiO2 films. In this paper, the thin films were characterized by UV-vis spectrophotometer and electrochemical workstation. The activity of the photocatalyst was also evaluated by photocatalytic degradation rate of aqueous methyl orange under UV radiation. The results illustrate that the TiO2 thin film doped by Mn non-uniformly at the optimal dopant concentration (0.7 at %) is of the highest activity, and on the contrary, the activity of those doped uniformly is decreased. As a comparison, in 80 min, the degradation rate of methyl orange is 62 %, 12 % and 34 % for Mn non-uniform doping film (0.7 at %), the uniform doping film (0.7 at %) and pure titanium dioxide film, respectively. We have seen that, for the doping and the pure TiO2 films, the stronger signals of open circuit potential and transient photocurrent, the better photocatalytic activity. We also discusse the effect of dopant concentration on the photocatalytic activity of the TiO2 films in terms of effective separation of the photon-generated carriers in the semiconductor. (C) Versita Warsaw and Springer-Verlag Berlin Heidelberg. All rights reserved.

稠油污染土壤生物修复的微生物筛选及工艺调控

稠油组分非常复杂，胶质沥青质含量较高，使稠油污染土壤的生物修复难度很大。对稠油中胶质沥青质分的降解是彻底修复稠油污染土壤的关键。试验中利用辽河油田污染土壤中筛选并纯化出来的几株细菌、真菌和放线菌，以胶质沥青质作为碳源，考察不同菌株处理的去除率变化。发现0d-14d期间是微生物去除胶质沥青质的活跃期，42d之后土壤中胶质沥青质的减少趋缓，是生物修复的转折点。筛选出优势降解菌株：细菌22B；真菌中F2006、F2008、F9902，放线菌A2013、A2016混合菌F2006+22B、F6＋22B。同时考查了表面活性剂吐温-80对菌株去除胶质沥青质能力的影响，发现吐温-80对不同菌株有促进或抑制作用。利用上述优势菌株处理5ryn稠油污染土壤，并在42d时，通过采取补加菌液、添加N、P营养物质和添加碳源处理来提高微生物对土壤中稠油的去除能力。经过56天的处理，细菌22B对稠油的去除率最高，达27．420＆；混合菌的去除率在23.64％-26.24％。比较三种处理措施对微生物降解稠油能力的影响时，发现不同菌株对这三种措施的反应并不相同。同时土壤中残留石油烃的族分析证实了土壤中的重质成分是可以被微生物降解的；而稠油污染土壤中的烷烃和芳香烃的含量则呈现动态变化。稠油污染土壤的生物修复后的毒性检验表明，不同菌株处理土壤的毒性因选择的菌株及采取的措施不同而异，其中土壤毒性最小的是22B添加碳源处理；毒性最强的是F2008加菌处理。补加菌液、添加营养和碳源措施会使微生物对稠油降解能力有所加强，但是也加速了某些微生物产生毒性较稠油更大的中间产物的生成，使土壤更加不适合植物的生长。本研究从辽河油田污染土壤中筛选出石油烃降解菌株，对稠油中最难降解的胶质沥青质进行处理，从中选择优势的降解菌株对稠油污染土壤进行生物修复，为稠油污染土壤的生物修复打下理论基础。

形状填充率的物体识别算法

针对经典形状上下文算法对物体关节相对位置变化敏感的缺点,提出一种基于剪影局部形状填充率的物体识别算法.该算法以物体不同的轮廓控制点为圆心,计算不同半径下物体剪影像素所占总像素的比例,即为控制点的局部形状填充率;将不同控制点、不同半径长度所计算的形状填充率数值构成一个特征矩阵,该矩阵反映了物体整个剪影的统计特性.通过不同数据库的实验结果表明,文中算法对物体的细节有很强的描述能力,对物体关节的相对位置不敏感,并且受剪影轮廓控制点数量影响小.

Genome-wide analysis of restriction-modification system in unicellular and filamentous cyanobacteria

Cyanobacteria are an ancient group of gram-negative bacteria with strong genome size variation ranging from 1.6 to 9.1 Mb. Here, we first retrieved all the putative restriction-modification (RM) genes in the draft genome of Spirulina and then performed a range of comparative and bioinformatic analyses on RM genes from unicellular and filamentous cyanobacterial genomes. We have identified 6 gene clusters containing putative Type I RMs and 11 putative Type II RMs or the solitary methyltransferases (MTases). RT-PCR analysis reveals that 6 of 18 MTases are not expressed in Spirulina, whereas one hsdM gene, with a mutated cognate hsdS, was detected to be expressed. Our results indicate that the number of RM genes in filamentous cyanobacteria is significantly higher than in unicellular species, and this expansion of RM systems in filamentous cyanobacteria may be related to their wide range of ecological tolerance. Furthermore, a coevolutionary pattern is found between hsdM and hsdR, with a large number of site pairs positively or negatively correlated, indicating the functional importance of these pairing interactions between their tertiary structures. No evidence for positive selection is found for the majority of RMs, e. g., hsdM, hsdS, hsdR, and Type II restriction endonuclease gene families, while a group of MTases exhibit a remarkable signature of adaptive evolution. Sites and genes identified here to have been under positive selection would provide targets for further research on their structural and functional evaluations.

激光诱导等离子体光谱法检测合金钢组分的实验研究

激光诱导击穿光谱技术(LIBS)具有无需样品制备,原位快速分析,可进行实时控制的特点使其在钢铁冶炼控制中具有巨大的实际应用价值。本文以波长为1 064 nm的Nd∶YAG调Q固体激光器为激发光源,CCD为探测器,高合金钢GBW01605—01609系列为样品,在建立的LIBS实验装置上研究激光与合金钢之间的相互作用。系统地研究了观测距离、激光能量对高合金钢样品中激光诱导击穿谱特性的影响,并分析了LIBS信号的时间分辨特性,确定了将LIBS用于合金钢微量元素定量分析时的最佳实验条件。

7000米载人潜水器推进器故障容错控制分配研究

介绍了7000米载人潜水器推进系统的组成和推进器布置,描述了潜水器控制分配问题,对推进器推力和期望控制量进行了归一化处理.根据载人潜水器的推进器布置,建立了系统的控制分配模型,设计了推进器故障容错处理策略,研究了基于推力最小二范数的载人潜水器控制分配求解方法.采用基于伪逆矩阵与定点分配的混合控制分配求解算法,在半物理仿真平台上实验验证了控制分配求解算法的正确性和有效性.

Mandelbrot集与Julia集的图象生成算法

介绍一种在计算机上生成Ｍａｎｄｅｌｂｒｏｔ集和Ｊｕｌｉａ集图象的简易算法。该算法对计算机的软硬件要求均不高，在普通的微机以及工作站上均可实现。

分布式过程控制系统在大电流稳流控制中的应用

本文介绍了一个用于供电系统的ＤＰＣＳ，以及智能控制─实时专家系统控制在ＤＰＣＳ中的应用、特点和实现。

监控显示器及其在电力系统中的应用

这台显示器是根据某电力系统计算机控制的要求而设计的.本文简要介绍了设计特点及其在电力系统中实际应用的情况.本文介绍的监控显示器适用于工业过程控制.作者根据现场应用的经验,提出了研制工业监控显示器的一些想法.

PASSIM卷接机组新型电控系统的设计与实现

PASSIM卷接机组原控制系统采用电路板进行逻辑控制,抗干扰性能差,故障率高,造成生产效率降低、原材料消耗增大、维修工作繁重等。为此,设计了一套新型卷接机组电气控制系统。该系统采用PLC进行过程控制,以工控机为上位机完成人机通信,采用交流伺服驱动,并通过高速信号处理专用系统完成重量检测控制及烟支质量检测功能;利用PROFIBUS、CAN及MPI多种总线方式完成各单元间的通讯,实现信号和数据间的传递和共享。改进后的PASSIM机组运行稳定可靠,采样速度快,实时性强,且维修方便。机组的有效作业率由85%左右提高到90%以上,降低了卷烟纸和烟丝等原材料的消耗。

基于数字化生产模型的在线故障诊断技术研究

提出了一种基于数字化的生产模型,使用控制图、故障树分析和专家知识,能够进行制造过程实时监控的诊断,该模型提高了故障诊断系统的可靠性,并提供了可实际操作的可视化建模工具。所开发的在线统计过程控制系统能够根据生产事件的监测,动态响应制造过程变化。该系统运用可视化建模工具,根据专家经验进行故障树建模,通过故障树自动生成专家系统诊断规则库,实现诊断知识的自动获取。将该系统应用于汽车变速箱装配过程的检测与故障诊断,验证了方法的有效性。

鞍钢冷轧厂制造执行系统研究

鞍钢新轧钢股份有限公司冷轧厂制造执行系统(MES)覆盖了从接收用户合同到产品发货的整个生产经营活动。接收用户合同后,系统自动生成优化的主生产计划、要料计划和机组作业计划,在生产过程中,系统对生产状况进行全面跟踪,对出现的异常情况进行合理调度,并且,冷轧MES与上游厂、公司ERP、过程控制系统和厂级管理系统连成一体,协同工作。该软件在实际应用中取得了令人满意的效果。

基于CAN总线的分布式数据采集与控制系统

随着电子技术和计算机技术的不断发展，工业生产过程的控制系统正在向着智能化、数字化和网络化的方向发展。传统的集散控制方式和计算机分层控制方式已经开始让位于智能终端与网络结合的总线网络控制方式。当今，在工厂中过程控制环境下的分布式自动化系统变得越来越复杂，尤其系统内部的各设备之间需要快速交换大量的信息，以便实现对被控系统更为精确的控制和提供一些辅助的评价函数。这就意味着要不断增加带宽和提高通信速率以满足网络通信的需要。在现有的多种可利用网络设备中，CAN总线以其清晰的定义、极高的可靠性及其独特的设计，被认为是最能有效地解决这一问题的途径之一。而且市场上基于通信技术的产品中，就实时性考虑，由于CAN总线采用的非表意性的通信方式，因此其结构更为简单，实时性更好。基于此背景，我们以CAN总线作为通信媒介，将分布于各控制现场的传感器、执行器和控制器有序地连接起来，构成了一个基于CAN总线的分布式局域网络控制系统。本文首先介绍了基于CAN总线的分布式数据采集与控制系统的总体结构。然后从硬件方面描述了基于CAN总线的通信协议转换单元、数据采集单元和输出控制单元的功能、硬件配置及各单元功能的具体实现过程，给出了各单元的性能指标。软件方面，以C语言作为平台，开发了基于CAN总线的上位计算机管理与监控软件，实现了对整个网络设备的系统管理和系统控制功能。对于该总线系统，作者运用了PID控制和模糊控制算法实现了对水箱液位的控制，达到了理想的效果。基于CAN总线的控制系统很好地解决了集散控制系统难以解决的难题，模糊控制的应用能很好地把总线控制系统应用到具有非线性、大时滞和难于获得精确模型的控制系统中。

Mesoporous spinel MgAl2O4 prepared by in situ modification of boehmite sol particle surface: I Synthesis and characterization of the unsupported membranes

Mesoporous spinel membranes as ultrafiltration membranes were prepared through a novel sol-gel technique. By in situ modification of the sol particle surface during the sol-gel process, control of the material structure on a nanometer scale from the earliest stages of processing was realized. Nano-particles with a chocolate-nut-like morphology, i.e. spinel MgAl2O4 as a shell and gamma -Al2O3 as a core, were first revealed by HRTEM results. The formation of the spinel phase was confirmed by X-ray diffraction (XRD). N-2 adsorption-desorption results showed that the mesoporous membranes had a narrow pore size distribution. (C) 2001 Elsevier Science B.V. All rights reserved.

影响生育价值观因素的研究－传统回归分析与多层线性模型分析结果的比较

Based on the research of predictors of VOC, this study explores the predictive effect of factors, such as generation, urban/rural context, collectivism/individualism orientation, family value, independent/interdependent self, adult attachment, on the Emotional and Traditional factors of VOC. Considering the hierarchical data structure of the VOC study, which resulted from the original research design, this dissertation applies Hierarchical Linear Model (HLM) after using traditional regression. A comparison between the results from the tow statistical methods is made, and the results are as follows: 1) Reliability coefficients of questionnaires used in this study are satisfactory, and most of them can be used in further research. 2) Samples from different generation and urban/rural context show significant differences on the score of collectivism/individualism orientation, family value, independent/interdependent self, adult attachment, and VOC. 3) Regression equations with VOC as outcome variable differ from each other when using data from sample with restricted generation or urban/rural context. 4) Results by HLM shows that interdependent self and mother identity have positive effect on emotional factor of VOC. Emotional factor’s variation on family level is not significant. 5) Results by HLM shows that Individualism, Interdependent Self and Grandmother Identity can predict Traditional factor of VOC. Traditional factor’s variation is significant on family level, which can be explained by family income and it’s area-urban or rural. Based on the results above, the researcher concludes that a) generation identity and urban/rural context have important effect on VOC; b) Interdependent Self is an important predictive factor of VOC’s Emotional factor, which is nearly subjective to other factors; d) VOC’s traditional factor varies with other factors, which show its strong relation with culture and tradition; e) more exact results can be gotten from HLM analysis, which beyond tradition regression.