网络通讯在淬火机控制中的重要作用

包钢宽厚板淬火钢板是具有较强的竞争力产品,其中淬火机的稳定工作对生产至关重要。良好的网络通讯是保证淬火机稳定生产的先决条件。文章主要介绍了淬火机控制系统中网络通讯的问题及改良措施。     

中厚板辊式淬火机淬火工艺自动控制系统开发及应用

为满足中厚板热处理线高强度板材产品的淬火工艺开发需要,通过构建基础自动化和过程自动化两级控制系统,自主开发出中厚板辊式淬火机淬火工艺控制系统。基础自动化用于满足淬火机的顺序控制、逻辑控制及设备控制功能,工艺过程控制用于实现淬火工艺参数的模型计算及设定,实现了中厚板辊式淬火机淬火过程的自动控制。将该工艺系统用于中厚板淬火工艺开发及生产,淬火后板材平直度及性能指标达到或优于国外同类进口先进设备的工艺技术水平。     

100～150mm超厚规格钢板淬火工艺研究

通过系统研究超厚规格钢板淬火工艺,建立超厚规格钢板淬火水量模型,科学合理分配高压段水量,实现有效冷却水量最大化;开发超低淬火速度和负压下量淬火新工艺,创新开发了增加淬火机低压段摆动冷却时间新工艺;完成淬火炉超厚规格钢板加热数学模型工艺与淬火机框架提升极限高度开发,使超厚规格钢板淬火能力得到提升。综合实施后,突破热处理生产线原有设计,成功实现了100~150 mm超厚规格钢板的淬火生产。     

湛钢厚板厂淬火机控制功能的改进

湛钢厚板厂的淬火机电控部分由东北大学设计建造,其目的是满足对淬火工艺的需要。结合生产实际,分析了淬火机的设备组成与控制结构,对淬火机控制的薄弱环节进行了说明。结合现有淬火工艺的分析和研究,对淬火机相关控制设备进行改进,实现淬火机辊道速度控制的灵活变化和提高弱冷段喷嘴调节精度等方案,摸索出一套适合现场的新的冷却工艺,有效地解决了工艺参数调整不灵活、资源浪费较多的问题,同时保证了设备控制精度。     

高效淬火机过程控制计算机系统

以太原钢铁公司五轧厂淬火机改造为背景，介绍了高效淬火机过程控制计算机系统的构成及其实施方法。该控制控制通过对系统中模型参数和参数的自学习达到对钢板实时跟踪与喷水，从而实现对淬火温度的精确控制。所采取的一系列措施已成功应用于高效淬火机。     

可移动新型淬火机的研发及应用

主要介绍了天津钢铁集团有限公司技术中心轧钢实验室可移动新型淬火机的主要用途、结构、工作原理及选型设计过程。列举出淬火机在使用过程中的主要特点和需要注意的事项,为实现淬火操作标准化提供了支持。     

降低淬火机吨钢水耗研究

介绍了中厚板卷厂淬火冷却设备的特点,结合现场实际情况,针对薄规格淬火钢板水耗高的问题分析研究,以精细化管理为抓手,通过人、机、料、法、环、测分析,发掘影响淬火机吨钢水耗指标的重要因素,使淬火机吨钢水耗由140 m3/t下降到110 m3/t。     

淬火机高淬段辊道问题分析及改进

针对兴澄特钢热处理线淬火机高淬段辊道使用过程中出现的问题进行分析并逐一改进和优化。改进后增加了设备的作业率,改善了淬火板质量,提高了经济效益,希望为中厚板厂热处理线淬火机的应用实践提供一些借鉴经验。     

武钢双频淬火机控制功能的改造

介绍５０Ｈｚ／２５０Ｈｚ双频感应加热淬火机在冷却和加热时控制功能的改造。通过长期生产实践使淬火轧辊端部避免或减少淬火环状裂纹，实现双频淬火机斜喷改造后温度闭环全自动控制。     

临钢淬火机过程控制系统的开发及应用

国内首套具有自主知识产权的淬火机成套设备在临钢投产以来,设备运行稳定,各项指标均符合预期要求.其中,集成多种开发环境组成的过程控制系统发挥了重要作用.本文对辊式淬火机过程控制系统的构成和实施方法进行了介绍,对数学模型进行了说明.采用过程控制系统对淬火过程进行控制后,产品性能显著提高,最终实现淬火设备的自动控制和高精度控制.     

Fluorescence studies of the location and membrane accessibility of the palmitoylation sites of rhodopsin

Fluorescent fatty acid labels have been incorporated into the palmitoylation sites of rhodopsin and used to probe the membrane accessibility and location of these sites. The fluorescence properties of anthroyloxy and pyrenyl fatty acids bound to rhodopsin were investigated in a reconstituted vesicle system. Collisional quenching of fluorescence by stearic acid (DSA) labeled with doxyls in the 16, 12, and 5 positions was used to determine the membrane accessibility and disposition of the modifying fatty acids. To properly determine the membrane concentration of these quenchers, the dependence of the Stern-Volmer parameters on both quencher and vesicle concentration was determined. An analysis of these dependences provided a correction for partitioning of the quencher between the aqueous phase and the membrane. After this correction, the relative effectiveness of doxyl quenchers was 16-DSA > 12-DSA > 5-DSA. Parallel studies on free anthroyloxy and pyrenyl fatty acids incorporated into the reconstituted system showed the same dependence on quencher position. These results indicate that the labels at the palmitoylation sites of rhodopsin are situated in the membrane much as a free fatty acid. This anchoring of the palmitates in the membrane results in the formation of a fourth cytoplasmic loop.     

水力喷射器高铬铸铁喷嘴与喉管的研制与应用

设计并制造了应用于水力喷射器的高铬铸铁喉管与喷嘴,金相检验表明,其铸态组织为细小均匀的圆形或六角形杆状（Cr,Fe）7C3型碳化物＋奥氏体,淬火＋回火后的组织为（Cr,Fe）7C3型碳化物＋回火马氏体＋少量残余奥氏体,H RC62～64。经装机试用,喷嘴使用寿命达20个月,比原用产品提高了13个月;喉管的使用寿命达10个月,比原用产品提高了5个月。     

Photoelectrochemical effects in the electrolyte-pigment-metal system. I. Metal-free phthalocyanine film description of short-circuit photocurrents for thin films of pigment

Short-circuit photocurrents produced by a semitransparent metallic electrode covered with multilayers of chlorophyll and immersed in an electrolyte have been studied. The action spectrum of maximum photocurrent is identical to the absorption spectrum of the film of pigment. The kinetics of rise of the photocurrent are photoindependent for thin multilayers but dependent on thickness. Comparison of efficiency of light energy conversion on the basis of short-circuit photocurrent seems to show that the stack of Chl a monolayers is the more efficient chlorophyll solid system. Introduction for the same number of Chl a molecules of vitamin K1 and Phytol shows that vitamin K1 acts probably like an excitation quencher as in monolayers at the water-air interface.     

焦炉4车自动对位系统的应用

主要介绍焦化厂6m焦炉4大车（推焦车、拦焦车、熄焦车、加煤车）自动对位联锁推焦、加煤系统的结构组成、基本原理、功能和使用效果。     

中厚板淬火机集管流场的数值模拟与参数优化设计

对中厚板无约束淬火机集管流场进行了数值模拟,得到了管内流体的流动特性;建立了基于喷水强度目标函数的集管结构参数优化模型,取得了理想的设计效果.     

Introduction of a tryptophan reporter group into the ATP binding motif of the Escherichia coli UvrB protein for the study of nucleotide binding and conformational dynamics

The DNA-dependent ATPase activity of UvrB is required to support preincision steps in nucleotide excision repair in Escherichia coli. This activity is, however, cryptic. Elicited in nucleotide excision repair by association with the UvrA protein, it may also be unmasked by a specific proteolysis eliminating the C-terminal domain of UvrB (generating UvrB*). We introduced fluorescent reporter groups (tryptophan replacing Phe47 or Asn51) into the ATP binding motif of UvrB, without significant alteration of behavior, to study both nucleotide binding and those conformational changes expected to be essential to function. The inserted tryptophans occupy moderately hydrophobic, although potentially heterogeneous, environments as evidenced by fluorescence emission and time-resolved decay characteristics, yet are accessible to the diffusible quencher acrylamide. Activation, via specific proteolysis, is accompanied by conformational change at the ATP binding site, with multiple changes in emission spectra and a greater shielding of the tryptophans from diffusible quencher. Titration of tryptophan fluorescence with ATP has revealed that, although catalytically incompetent, UvrB can bind ATP and bind with an affinity equal to that of the active UvrB* form (Kd of approximately 1 mM). The ATP binding site of UvrB is therefore functional and accessible, suggesting that conformational change either brings amino acid residues into proper alignment for catalysis and/or enables response to effector DNA.     

Comparison of adriamycin and derivatives uptake into large unilamellar lipid vesicles in response to a membrane potential

The uptake of adriamycin (ADM) and several derivatives into large unilamellar vesicles (LUV) displaying a transmembrane potential and having a lipid composition close to that of the inner mitochondrial membrane has been measured. Drug association to neutral liposomes, made of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) (70:30, w/w) was shown to be potential-dependent: in the absence of potential, accumulation of drug was almost undetectable, whereas between 11 and 50 nmol of drug/mumol phospholipid, depending on the anthracycline used, was associated to LUV exhibiting a membrane potential after 1 h incubation. Association of drugs to LUV with a lipid composition closer to that of the inner mitochondrial (cardiolipin, CL, 20%; PC 50%; PE, 30%, w/w) and displaying a membrane potential is higher than with neutral vesicles (between 40 and 76 nmol of anthracycline/mumol phospholipid after 1 h incubation). Since it is known that ADM and derivatives have a high affinity for CL, a fraction of the associated drug may bind to CL on the outer side of the vesicles. This was confirmed by the fact that, in the absence of potential, between 40 and 56 nmol of anthracycline/mumol phospholipid was still associated to LUV containing CL. In order to discriminate between drug adsorbed at the surface of the LUV and drug accumulated inside the LUV, an anthracycline fluorescence quencher (I-) was used. It was shown on neutral LUV displaying a membrane potential, that between 55 and 81% of the associated drug is actually entrapped inside the vesicles, inaccessible to the quencher. These percentages decreased to between 41 and 68%, respectively, in the presence of LUV containing CL and exhibiting a membrane potential, whereas for LUV of the same composition but displaying no membrane potential almost all the associated drug is adsorbed on the outer face of the LUV, accessible to the quencher, and likely bound to CL. This study brings evidence that antitumour anthracyclines despite important structural homologies do not accumulate to the same extent into vesicles mimicking the lipid composition and the membrane potential of mitoplasts. This ability to reach the matrix compartment of mitochondria could partly explain the differences of cardiotoxicities associated to anthracyclines with closely related molecular structure.     

Quantitative polymerase chain reaction-based homogeneous assay with fluorogenic probes to measure c-erbB-2 oncogene amplification

We describe a PCR-based assay for determining c-erbB-2 oncogene amplification in breast cancer in which we use the TaqMan system. Two fluorogenic probes anneal to the target between primers for c-erbB-2 and beta-globin genes and contain both a reporter dye (6-carboxy-fluorescein) and a quencher dye (6-carboxy-tetramethyl-rhodamine). During the extension phase of the PCR cycle, the 5'-->3' exonuclease activity of Taq polymerase cleaves the hybridized fluorogenic probe, resulting in an increase of fluorescence emission of the reporter dye that is quantitative for the amount of PCR product and, under appropriate conditions, for the amount of template. Assay performance showed adequate precision and a lower detection limit and good correlation with the results obtained in the same samples by a competitive PCR assay (n = 25, r = 0.94, P < 0.01). This homogeneous assay is time-saving, avoids usually cumbersome postamplification procedures (that can be additional sources of inaccuracy and contamination), and seems suitable for determination of c-erbB-2 oncogene amplification in tumor specimens.     

Hydrogen peroxide-dependent generation of singlet molecular oxygen by human saliva: its detection by chemiluminescence from a Cypridina luciferin analog

By the addition of hydrogen peroxide to human saliva, chemiluminescence from Cypridina luciferin analog (CCLA) and oxygen evolution were observed. Chemiluminescence was inhibited by inhibitors of salivary peroxidase, azide and cyanide and by a singlet oxygen quencher, crocin. Deuterium oxide (99.75%) stimulated the initial increase of CCLA by 15-50% and the integrated CCLA 2.1-3.6-fold. The results suggest that the generation of singlet oxygen by peroxidase in human saliva depends on hydrogen peroxide.     

Evidence for singlet oxygen-induced cross-links and aggregation of collagen

Singlet oxygen, generated by a hematoporphyrin-photosensitized reaction, was shown to cause insolubilization and an increase in molecular weight of acid soluble type I collagen and vitreous collagen as manifested in sodium dodecyl sulfate polyacrylamide gel electrophoresis. No such changes in the molecular properties of collagen could be observed when the irradiation was carried out in the presence of sodium azide, a singlet oxygen quencher. The increase in molecular weight and insolubilization of the collagen solution was attributed to extensive cross-links in the protein molecules.