浅析如何在线实现中厚板轧机全自动轧钢控制功能

本次研究主要分析了实现中厚板轧机生产线全自动轧钢功能的过程情况。并且还对比了轧制过程的手动控制以及轧制过程的全自动控制,针对实现了全自动轧钢控制功能实现的总结分析。争取在两级计算机控制系统中,合理的、有效的分配全自动轧钢的控制功能,在使用过程控制系统以及基础自动化系统的基础上实现有效的协调以及配合,最后从根本上促使轧制过程水平方向辊道控制得以实现,并且还可以从根本上实现垂直方向道次数设定控制,同时还可以实现轧制道次控制。这都属于全自动的轧钢控制功能表现。轧线的自动化水平可以由全自动轧钢控制功能的实现来有效的提升。     

双蓄热式板坯加热炉控制系统

为了实现双蓄热式板坯加热炉的炉温准确控制并降低能耗,开发了双蓄热式加热炉控制系统。系统由L1、L2控制系统共同构成。L1系统主要实现板坯测宽测长、炉前定位、炉膛压力控制、燃烧控制等;L2系统主要实现数据通信、物料跟踪、板坯温度计算、板坯温度预测、温度计算自适应等,并与L1控制系统共同实现自动燃烧控制。应用效果表明,该系统实现了板坯温度的准确控制,节约了人力,降低了能耗,提高了钢卷产品质量。     

炼钢路干法布袋除尘自动化系统的研究与设计

基于PLC控制系统,在布袋除尘系统中利用复杂逻辑控制、矩阵控制、顺序控制、PID控制等先进控制理念和方法,实现矩阵式脉冲阀精确控制,定时、差压、混合等多种方式自动反吹清灰控制和"一键卸灰"自动控制等。布袋除尘自动化系统的实现,提高了布袋除尘系统的工艺控制水平和生产效能,显著提高环境治理质量,实现除尘系统无人值守。     

S120变频器伺服控制在飞剪转折器中的应用

为满足棒材生产线高速区飞剪生产的控制要求,通过应用S120变频器的位置控制功能,实现了转折器伺服电机的快速、精确的位置控制,实现了棒材生产线生产稳定运行。     

S120变频器在转炉倾动中的主从控制方案比较

介绍了转炉倾动过程中的负载特性、西门子S120变频器的特点、变频传动配置及控制方案,给出了在转炉倾动控制中应用S120变频器实现主从控制的两种方案和实现方法,并进行了比较.     

国产DCS系统在除盐水系统的应用

介绍了除盐水系统的工艺流程和配置、反渗透和电除盐技术的原理,分析了系统的控制要求,提出了采用国产DCS系统的控制方案,给出了实现本地加远方控制的网络结构,详述了具体IO配置及控制功能的实现方案,总结了实际应用情况。     

环形加热炉的电气控制

介绍了环形加热炉的电气控制功能及实现,重点介绍装料控制、炉底机械旋转控制、出料控制、扒渣控制及自动出渣控制。在加热管坯品种多且规格更换频繁的复杂工况下,非常难能可贵地实现了整个生产过程的全自动,出料节奏及管坯加热质量完全满足工艺要求。     

进度控制是项目管理的关键环节

在项目管理中,进度控制是整个项目控制过程中重要的环节之一,它与质量控制、费用控制共同决定了能否实现包括项目的收费目标在内的各项目标,特别是进度控制在实际工作中的有效运用,这对于实现项目的各项目标进而完成项目的最终收费目标、促进公司的发展壮大以及实现各项战略目标,都有着极为重要的意义。     

冷轧机组厚度控制的实现方式

本文先从冷轧机组厚度控制的实现方式原理入手,阐述了冷轧机组厚度控制的实现方式,由于目前冷轧机组厚度控制方式较多,本文集中阐述2种厚度控制方式,最后总结了全文,旨在为不断完善冷轧机组厚度控制的实现方式。     

PLC在余热锅炉控制系统中的应用

介绍利用SIEMENS公司S7-200PLC实现了余热锅炉的实时监控与自动化控制,阐述了系统的硬件配置、控制方案设计、软件实现及其特点。     

电感耦合等离子体原子发射光谱法测定高碳除尘灰中11种元素

实验重点探讨了高含量碳对除尘灰样品中镁、铝、钾、钙、铬、锰、铜、钡、铅、镉、锌等元素测定的影响,并解决了除碳的问题。样品使用马弗炉高温除碳,采用盐酸-硝酸-氢氟酸-高氯酸消解样品灰分,选择了镁、铝、钾、钙、铬、锰、铜、钡、铅、镉、锌等元素的分析谱线和扣背景模式,建立了使用电感耦合等离子体原子发射光谱法(ICP-AES)测定高碳除尘灰中镁、铝、钾、钙、铬、锰、铜、钡、铅、镉、锌等元素的方法。在仪器最佳工作条件下,各元素校准曲线线性相关系数r均大于0.999 5,方法检出限在1.08～26.01 mg/kg之间。方法应用于除尘灰实际样品中镁、铝、钾、钙、铬、锰、铜、钡、铅、镉、锌的测定,结果的相对标准偏差(RSD,n=11)为0.90%～7.1%,目标元素的加标回收率为90%～117%;按照实验方法测定除尘灰中镁、铝、钾、钙、锌,结果与火焰原子吸收光谱法(FAAS)的测定结果相吻合。     

电感耦合等离子体原子发射光谱法测定铍中11种杂质元素

铍中铝、钴、铬、铜、铁、镁、锰、镍、铅、硅和锌等11种杂质元素含量的准确测定,是判定铍材是否合格的重要指标。目前,上述杂质元素的测定标准为GJB 2513A—2008《铍化学分析方法》,方法分别采用光度法和原子吸收光谱法对各元素逐一测定,测定周期很长。试验采用盐酸-硝酸溶解样品,选择Al 308.215nm、Co 230.786nm、Cr 284.325nm、Cu 324.754nm、Fe 261.187nm、Mg 285.213nm、Mn 260.569nm、Ni 221.647nm、Pb 182.205nm、Si 250.690nm、Zn 213.856nm为分析谱线,采用标准加入法(MSA)配制标准溶液系列消除基体效应的影响,使用电感耦合等离子体原子发射光谱法(ICP-AES)测定铝、钴、铬、铜、铁、镁、锰、镍、铅、硅和锌,从而建立了铍中11种元素的测定方法。各待测元素校准曲线的线性相关系数均大于0.9995;各元素的定量限为0.001%~0.002%。实验方法用于测定铍样中铝、钴、铬、铜、铁、镁、锰、镍、铅、硅和锌,结果的相对标准偏差(RSD,n=10)为0.63%~8.6%,回收率为90%~110%。按照实验方法测定铍样中上述11种元素,测定结果与采用GJB 2513A—2008测定的结果吻合。     

火焰原子吸收光谱法测定铁矿石中Zn、Co、Ni、Pb、Cr含量

研究了应用火焰原子吸收光谱法测定铁矿石中Zn、Co、Ni、Pb、Cr微量元素，研究了基体干扰及消除方法，同时考察了介质，采用盐酸、高氯酸、硝酸、氢氟酸等分解试样。Zn、Co、Ni、Pb、Cr的检出限为(％)：0．0002，0．0002，0．0003，0．0002，0．0005。     

Management of Fluid Mud in Estuaries, Bays, and Lakes. II: Measurement, Modeling, and Management

Techniques for measurement, modeling, and management of fluid mud are available, but research is needed to improve them. Fluid mud can be difficult to detect, measure, or sample, which has led to new instruments and new ways of using existing instruments. Multifrequency acoustic fathometers sense neither density nor viscosity and are, therefore, unreliable in measuring fluid mud. Nuclear density probes, towed sleds, seismic, and drop probes equipped with density meters offer the potential for accurate measurements. Numerical modeling of fluid mud requires solving governing equations for flow velocity, density, pressure, salinity, water surface, plus sediment submodels. A number of such models exist in one-, two-, and three-dimensional form, but they rely on empirical relationships that require substantial site-specific validation to observations. Management of fluid mud techniques can be classified as those that accomplish: Source control, formation control, and removal. Nautical depth, a fourth category, defines the channel bottom as a specific fluid mud density or alternative parameter as safe for navigation. Source control includes watershed management measures to keep fine sediment out of waterways and in-water measures such as structures and traps. Formation control methods include streamlined channels and structures plus other measures to reduce flocculation and structures that train currents. Removal methods include the traditional dredging and transport of dredged material plus agitation that contributes to formation control and/or nautical depth. Conditioning of fluid mud by dredging and aerating offers the possibility of improved navigability. Two examples—the Atchafalaya Bar Channel and Savannah Harbor—illustrate the use of measurements and management of fluid mud.     

Review of Alcoholism: A bio-psycho-social approach.

Reviews the book, Alcoholism: A bio-psycho-social approach by Jerome David Levin (1990). This small volume sets its task as providing counseling students with a comprehensive knowledge base "summarizing biochemical, pharmacological, physiological, anthropological, sociological, epidemiological, historical, and psychological findings on alcohol and its use and abuse" (Preface, p. xi). It treats each of these, in varying degrees of depth, in seven chapters. Perhaps the greatest strength of the book is its thorough presentation of the medical consequences of alcoholism, the mechanisms involved, and the interplay between biological and psychological factors. Unfortunately, this volume does not provide sufficient coverage of treatment-related issues. It may serve as an introductory overview of the alcoholism field for undergraduate or graduate students, or professionals from other fields. It is too advanced, however, in its use of concepts and language, for paraprofessional students. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

电感耦合等离子体原子发射光谱法测定锰铁合金、锰硅合金和金属锰中8种微量元素

锰铁合金、锰硅合金、金属锰中铅、砷、钛、铜、镍、钙、镁、铝的含量决定了产品质量,以往常采用化学法或原子吸收光谱法进行测定,但存在准确度较差或测定速度不能满足要求等问题。为了实现上述元素的准确、快速测定,建立了采用电感耦合等离子体原子发射光谱法(ICP-AES)测定锰铁合金、锰硅合金和金属锰中微量铅、砷、钛、铜、镍、钙、镁、铝的方法。实验以硝酸、盐酸、氢氟酸、高氯酸分解样品,并使硅与氢氟酸反应生成四氟化硅挥发除去,试液中剩余共存元素主要有铁、锰等。实验结果表明,铁不干扰测定,通过在标准溶液系列中进行锰基体匹配消除锰基体效应的影响。以2mL高氯酸和6mL盐酸混合酸(8%)作为分析介质,可以达到最佳分析效果。在各元素校准曲线线性范围内,线性相关系数在0.9992~0.9999之间;方法中各元素的检出限在0.0001~0.0040μg/mL。实验方法用于测定锰铁合金、锰硅合金、金属锰中铅、砷、钛、铜、镍、钙、镁、铝,结果的相对标准偏差(RSD,n=11)在2.2%~9.4%;回收率在95%~105%;选择7个实验室进行了验证试验,各实验室间结果基本一致;按照实验方法测定了4个标准样品(材字-32、YSB C 28618、YSB C 26605)中铅、砷、钛、铜、镍、钙、镁、铝,结果与认定值相吻合。     

电感耦合等离子体原子发射光谱法测定硅铁钡孕育剂中9种元素

采用硝酸和氢氟酸溶解样品,高氯酸冒烟驱尽硝酸-氢氟酸,盐酸溶解盐类,选择Ba 233.527nm、Fe 259.940nm、Ca 317.933nm、Mn 257.610nm、Cr 267.716nm、Al 394.401nm、Ni 231.604nm、Cu 327.396nm、P 178.284nm为分析线,使用电感耦合等离子体原子发射光谱法(ICP-AES)测定钡、铁、钙、锰、铬、铝、镍、铜、磷,从而建立了硅铁钡孕育剂中钡、铁、钙、锰、铬、铝、镍、铜、磷等9种元素的测定方法。各元素校准曲线的相关系数均大于0.9995;方法中各元素检出限为0.00006%~0.00069%。按照实验方法测定标准样品GSB03-1607-2003中钡、铁、钙、锰、铬、铝、镍、铜、磷,结果的相对标准偏差(RSD,n=11)为0.63%~3.4%。实验方法用于测定标准样品GSB03-1607-2003和YSB14607-2001中钡、铁、钙、锰、铬、铝、镍、铜、磷,测定值与认定值基本相符。     

Contrasting Clogging in Granular Media Filters, Soils, and Dead-End Membranes

Clogging in porous media is a problem in environmental engineering, hydrogeology, soil science, and petrology. However, a comparison of the literature reveals qualitatively different clogging behavior in different porous media: in granular media filters, increasing clogging is associated with slower flow, more flocculated conditions, and smaller fractal dimensions. In soils and dead-end membranes, increasing clogging is associated with faster flow, more dispersed conditions, and larger fractal dimensions. This paper documents these differences, discusses them in light of two key intermediate variables, colloid accumulation and deposit morphology, then presents a new conceptual model that explains the reported clogging phenomena as a function of specific deposit, fractal dimension, and a new variable, deposit location. Testing this model is possible using recently introduced experimental techniques.     

分光光度-遗传算法同时测定锌、镉、钴、镍、锰

在pH9.3,乳化剂OP存在下,Zn2+,Cd2+,Co2+,Ni2+,Mn2+与5-Br-PADAP发生灵敏的显色反应,所形成的三元胶束络合物的吸收光谱严重重叠,单独测定相互干扰严重。本文将分光光度法与遗传算法相结合,对同一混合体系的总吸光度值进行解析,实现了5种组分的同时测定。模拟样品测定的相对误差一般小于±10%。     

Pollutant Removal and Peak Flow Mitigation by a Bioretention Cell in Urban Charlotte, N.C.

Bioretention is a stormwater treatment practice that has gained popularity due to its aesthetics, potential to reduce flooding, and early documented improvements to stormwater quality. A bioretention cell in an urban setting was examined in Charlotte, N.C. from 2004 to 2006. Flow-weighted, composite water quality samples were collected for 23 events and analyzed for TKN, NH4-N, NO2-3-N, TP, TSS, BOD-5, Cu, Zn, Fe, and Pb. Grab samples were collected from 19 storms for fecal coliform and 14 events for Escherichia coli (E. coli). There were significant reductions (p<0.05) in the concentrations of TN, TKN, NH4-N, BOD-5, fecal coliform, E. Coli, TSS, Cu, Zn, and Pb. Iron concentrations significantly increased (p<0.05). NO2-3-N concentrations were essentially unchanged. Efficiency ratios for TN, TKN, NH4-N, TP, and TSS were 0.32, 0.44, 0.73, 0.31, and 0.60, respectively. Fecal coliform and E. coli efficiency ratios were 0.69 and 0.71, respectively. Efficiency ratios for Zn, Cu, and Pb were 0.77, 0.54, and 0.31, respectively. Concentrations of Fe increased by 330%. The peak outflow of the bioretention cell for 16 storms with less than 42?mm of rainfall was at least 96.5% less than the peak inflow, with a mean peak flow reduction being 99%. These results indicated that in an urban environment, bioretention systems can reduce concentrations of most target pollutants, including pathogenic bacteria indicator species. Additionally, bioretention can effectively reduce peak runoff from small to midsize storm events.