链篦机-回转窑铲料板的改造

链篦机-回转窑氧化球团生产线铲料板是把链篦机篦床上的料球导入回转窑的关键部件,其使用效果对整个链篦机-回转窑氧化球团生产至关重要。本文介绍了莱钢通过链篦机铲料板改造,彻底解决了制约链篦机-回转窑生产的一大难题。     

链篦机-回转窑-环冷机氧化球团工艺设计及实践

探究链篦机-回转窑-环冷机氧化球团工艺设计过程中的设备选型。通过分析某公司180万t链篦机-回转窑-环冷机氧化球团工程中干燥机、高压辊磨机、混合机、圆盘造球机等设备的选型优化,使类似生产规模链篦机-回转窑-环冷机氧化球团工程的工艺设备选型更好地服务于生产。     

链篦机-回转窑窑尾密封改造

链篦机-回转窑氧化球团窑尾密封是链篦机与回转窑连接的关键部位,它的密封效果对整个链篦机,回转窑氧化球团生产至关重要。本文介绍了通过窑尾密封改造,解决了影响链篦机一回转窑生产的诸多问题。     

我国发展链篦机——回转窑氧化球团的前景

文中简述了国内外链篦机—回转窑球团法的发展现状,总结了用链篦机—回转窑生产氧化球团矿的工艺技术特点,指出了我国发展链蓖机—回转窑法球团需注意的几个问题,论述我国发展链篦机—回转窑的前景。作者认为,近期内我国链篦机—回转窑球团最大单机产量以控制在500～1000kt/a为宜。同时,它最适于建在用煤粉作燃料的中型钢铁厂内。     

氧化球团链篦机-回转窑系统内衬长寿的实践

介绍了氧化球团链篦机-回转窑用耐火材料内衬的长寿化的实践,阐述了氧化球团链篦机-回转窑用耐火材料长寿化的实现途径,重点说明了回转窑窑体、链篦机预热段、环冷机下侧墙、环冷机受料斗等易损部位内衬结构的改进和新材料开发,同时介绍了氧化球团链篦机-回转窑系统的科学操作维护对内衬寿命的影响。     

对链箅机“隔墙导流”的思考

近十年来,国内链篦机-回转窑球团工艺发展迅速,“隔墙导流”是该工艺中比较突出且被广泛应用的技术之一.本文在分析、总结国内若干条具有代表性的链篦机一回转窑球团生产线后,对“隔墙导流”技术进行了深入探讨,期望与业界同行交流,以利于我国链篦机-回转窑球团技术的健康发展.     

链篦机物料平衡及热平衡计算

介绍了链篦机-回转窑系统中链篦机的工作原理,分析了链篦机的物料平衡和热平衡计算公式。     

链篦机─回转窑直接还原的工程原理概述

论述了链篦机──回转窑直接还原的工程原理．对如何避免和防止结圈。实现链篦机──回转窑长期、稳定作业的原则进行了深入探讨。     

链篦机——回转窑直接还原的工程原理概述

论述了链篦机－回转窑直接还原的工程原理，对如何避免和防止结圈，实现链篦机－回转窑长期，稳定作业的原则进行了深入探讨。     

莱钢型钢链篦机 回转窑智能控制系统及其应用

介绍了莱钢型钢炼铁厂120万t/a链篦机-回转窑智能控制系统,包括:物料配比实时动态控制,链篦机温度自优化控制,链篦机-回转窑-环冷机三机速度联调控制以及回转窑温度模糊控制等。实际运行效果表明,该控制系统结构合理,性能稳定,为球团生产线的高产、稳产和确保产品质量发挥了重要作用。     

一种新型轻量化高级轿车铝合金轮毂生产工艺

分析了目前铝合金轮毂生产工艺的特点,提出并验证了一种以锻造旋压为轮毂基体,以注塑件来满足外观造型的轮毂生产新工艺,并通过实际生产及轮毂试验验证,满足了高级轿车对轮毂高强度、轻量化,造型美的要求。     

米巴赫激光焊机重焊原因分析及其控制

连续化的生产作业大大释放了生产能力,降低了生产成本.焊机是冷轧连续化生产的根本保证.某钢厂酸轧生产线使用的是米巴赫激光焊机,实际生产中频繁的重焊对生产节奏产生了不利影响,可能导致冷轧工艺不合,出现停车废品.收集数据,使用Pareto图对影响重焊的原因进行了分析.分析发现,焊缝搭接是引起重焊的主要原因.为减少焊机重焊,对...     

Middle ear muscle activity during speech in stapedectomized and laryngectomized subjects

Middle ear muscle responses associated with speech production were observed in normal-hearing, stapedectomized, and laryngectomized subjects. Impedance changes associated with speech production were monitored by an electroacoustic impedance bridge simultaneously with vocal output. Results from stapedectomized subjects indicate that the tensor tympani muscle contracts prior to vocalization and is part of the neurological pattern of speech production. Data collected from laryngectomized subjects suggest that the presence of sensory fibers from the larynx is not a prerequisite for middle ear muscle activity during speech production.     

Spin trapping of azidyl and hydroxyl radicals in azide-inhibited rat brain submitochondrial particles

Succinate-driven respiration in azide-inhibited rat brain submitochondrial particles (smps) produces azidyl and hydroxyl radicals that were detected by spin trapping with 5,5'-dimethyl-1-pyrroline-N-oxide (DMPO). Production of radicals required succinate and oxygen and was eliminated by heat denaturation, which indicates that radical production is a result of respiration. The concentrations of both DMPO/.OH and DMPO/.N3 were decreased by addition of catalase to the smps, which indicates that H2O2 is involved in radical production. In the absence of azide anion, DMPO/.OH was not detected in the same system, even after five additions of succinate over a period of 24 h. It is proposed that azide inhibition of cytochrome c oxidase results in increased production of superoxide, which is efficiently converted to hydrogen peroxide by membrane-bound superoxide dismutase. Hydrogen peroxide activates endogenous peroxidase to react with azide anion forming azidyl radical, which damages the peroxidase, resulting in decreased production of azidyl radical with successive additions of succinate. Hydroxyl radical is produced from the hydrogen peroxide that is not removed by peroxidase. The increased production of superoxide in the azide-inhibited system suggests that loss of cytochrome c oxidase activity can lead to increased radical production if other proteins in the respiratory chain remain active. In the azide-inhibited system, reaction of azide anion with H2O2-activated endogenous peroxidase and spin-trapping of the resulting azidyl radical is a convenient monitor of H2O2 production.     

钢铁企业高炉炼铁的稳定生产

高炉生产的稳定对于整个钢铁企业生产流程来说至关重要,高炉炼铁生产的工序能耗和生产成本都占到了钢铁企业生产的70%以上。为了回答什么是高炉稳定的问题,通过数据统计计算、对比分析等研究方法,提出了一种判定高炉稳定的判据。对比分析了宝钢和首钢稳定性较好的高炉的焦比偏差,研究了高炉不同焦炭负荷和不同综合入炉品位条件下焦比递减额,探讨和揭示了高炉生产稳定水平的标准,提出了高炉生产稳定问题的技术观点。     

Inhibition of interferon gamma induced interleukin 12 production: a potential mechanism for the anti-inflammatory activities of tumor necrosis factor

Inflammation is associated with production of cytokines and chemokines that recruit and activate inflammatory cells. Interleukin (IL) 12 produced by macrophages in response to various stimuli is a potent inducer of interferon (IFN) gamma production. IFN-gamma, in turn, markedly enhances IL-12 production. Although the immune response is typically self-limiting, the mechanisms involved are unclear. We demonstrate that IFN-gamma inhibits production of chemokines (macrophage inflammatory proteins MIP-1alpha and MIP-1beta). Furthermore, pre-exposure to tumor necrosis factor (TNF) inhibited IFN-gamma priming for production of high levels of IL-12 by macrophages in vitro. Inhibition of IL-12 by TNF can be mediated by both IL-10-dependent and IL-10-independent mechanisms. To determine whether TNF inhibition of IFN-gamma-induced IL-12 production contributed to the resolution of an inflammatory response in vivo, the response of TNF+/+ and TNF-/- mice injected with Corynebacterium parvum were compared. TNF-/- mice developed a delayed, but vigorous, inflammatory response leading to death, whereas TNF+/+ mice exhibited a prompt response that resolved. Serum IL-12 levels were elevated 3-fold in C. parvum-treated TNF-/- mice compared with TNF+/+ mice. Treatment with a neutralizing anti-IL-12 antibody led to resolution of the response to C. parvum in TNF-/- mice. We conclude that the role of TNF in limiting the extent and duration of inflammatory responses in vivo involves its capacity to regulate macrophage IL-12 production. IFN-gamma inhibition of chemokine production and inhibition of IFN-gamma-induced IL-12 production by TNF provide potential mechanisms by which these cytokines can exert anti-inflammatory/repair function(s).     

Evidence for a unique elastic sheath surrounding the vesicular arteries of the rabbit urinary bladder--studies of the microvasculature with microscopy and vascular corrosion casting

AD is associated with a bias of the T helper cells to show increased IL-4 and reduced interferon-gamma (IFN-gamma) production. The production of IFN-gamma and IL-4 and the development of Th cells into either high IFN-gamma or high IL-4 producers is strongly influenced by factors produced by antigen-presenting cells (APC), like IL-12 and prostaglandin E2 (PGE2). IL-12 selectively enhances IFN-gamma production and favours the development of IFN-gamma-producing Th cells, whereas PGE2 selectively inhibits IFN-gamma production by Th cells. The aim of this study was to test whether the increased IL-4/IFN-gamma production ratio by Th cells in AD can be explained by an increased PGE2/IL-12 production ratio by the APC. Monocytes were used as APC source. PGE2 and IL-12 production by lipopolysaccharide (LPS)-stimulated monocytes from 12 AD patients and 12 non-atopic controls was determined using two complementary experimental systems, whole blood cultures and purified monocytes. In addition, we determined IL-6 production as a measure of monocyte activation, and IL-10 production because IL-12 production by monocytes is highly influenced by endogenously produced IL-10. The monocytes from AD patients showed normal production levels of IL-6 and IL-10, a two-fold, but non-significant decrease in IL-12 production, and a significantly (three-fold) higher PGE2 production than those from non-atopic controls. Here we show for the first time that enhanced PGE2 production by monocytes in AD is not accompanied by a general rise in cytokine production. We conclude that AD is indeed associated with an increased PGE2/IL-12 production ratio by monocytes.     

Automated Generation of Customized Field Data Collection Templates to Support Information Needs of Cost Estimators

While estimating activity production rates, cost estimators rely on historical production rates. To have realistic and useful cost estimates based on historical production rates, such production rate data should be augmented with historical contextual information that depict conditions under which activity production rates were achieved in past projects. This information is needed in determining which production rate to use among alternates for a similar activity existing in a new bid. Estimators need contextual information especially when they are unfamiliar with the work being estimated. Hence, such information items need to be identified, collected, and stored for estimators’ use in new projects. This paper details a construction-method specific and an extensible approach that is developed for enabling cost estimators to define contextual information items that need to be collected on job sites and stored as part of project histories. Based on this approach, the writers implemented a prototype system, called as ContextGen, and performed user-tests with estimators with different experience levels. Results showed that the developed approach captures method-specific information needs of estimators and is extensible to incorporate new contextual information items that can have different data representations. The developed approach is also precise in retrieving contextual information items specific to a construction method from a set of predefined contextual information items available in a library.     

The origin of androgen and estrogen in a virilized postmenopausal woman with bilateral benign cystic teratomas

Clitoromegaly was observed in a 73-year-old woman who had bilateral ovarian benign cystic teratomas that contained only epithelial derivatives. Scattered in the stroma of these ovaries were clusters of hyperplastic cells. The plasma testosterone production rate was 2.4 mg/day, a value that is ten times greater than that of normal postmenopausal women. The elevated plasma concentrations of testosterone and androstenedione decreased to normal by the second day after bilateral oophorectomy. Ovarian venous concentrations of testosterone and androstenedione were also increased and were considerably greater than those in peripheral blood. Estrone production was 68 microng/day, most of which could be accounted fo by the extraglandular formation from androstenedione. Estradiol production was 71 microng/day, of which 75% was computed to arise from extraglandular formation and the remainder likely arose by ovarian secretion. The modest increase in estrogen production was associated with slight cystic hyperplasia of the endometrium. From this study we conclude that the hyperplastic ovarian stroma was the source of the excessive androgen production.