滑板挡渣在八钢120t转炉的应用

文章介绍了八钢炼钢厂120t转炉通过现场改进,将原挡渣棒挡渣方式改为滑板挡渣。120t转炉滑板挡渣装置与PLC红外下渣检测装置结合,实行滑板挡渣,在八钢2#转炉和3#转炉首先进行应用,取得良好效果。     

转炉滑板挡渣出钢技术实践

介绍了滑板挡渣技术原理,及滑板挡渣技术在转炉上的应用和效果,滑板挡渣技术挡渣成功率高、挡渣效果好,转炉下渣量可控制在50 mm左右,为开发生产优质新品种提供质量保证。     

150t转炉滑板挡渣工艺技术应用实践

介绍了转炉滑板挡渣工艺技术在安钢150 t转炉上的应用情况。应用表明,滑板挡渣技术挡渣成功率高,能有效控制下渣量,改善钢水纯净度,为开发高附加值品种钢和提高产品质量奠定了基础。     

滑板挡渣系统在安钢150t转炉上的应用

简述了转炉挡渣工艺技术及滑板挡渣法的原理、结构和控制过程，并结合安阳钢铁集团公司150t转炉滑板挡渣系统的应用，介绍了适应性改造的措施和实际效果。滑板挡渣工艺的应用有效地减少了回磷及出钢过程的下渣量，达到优化钢质，提高经济效益的目的。     

宝钢250 t转炉滑板挡渣机构耐材使用实践

通过试验并结合生产实践,对转炉滑板挡渣机构内、外部耐材的使用寿命进行了统计和分析,同时对内部耐材进行了成分改良,进一步提高了滑板挡渣机构的在线使用寿命,为滑板挡渣机构离线维护工作量的减少和滑板挡渣机构在线更换次数的降低提供了有利支撑,对国内各大钢厂正在推广使用的转炉滑板挡渣法具有很好的推广价值.     

基于PLC自动控制和红外下渣检测的滑板挡渣技术应用

通过对转炉出钢过程中前期渣、中期渣和后期渣的分析,系统对比了挡渣球、挡渣塞、气动挡渣和滑板挡渣等挡渣方式的挡渣效果。滑板挡渣通过PLC自动控制系统采集转炉倾动角度,同时利用红外下渣检测判断下渣量。根据挡渣工艺要求,滑动水口的全开或全闭可在0.5 s内自动完成,实现出钢过程中前期渣、中期渣和后期渣的最有效阻挡。与其他挡渣方法相比,滑板的挡渣成功率达到100%,转炉出钢下渣量控制在50 mm,回磷稳定控制在0.002%以下,降低了钢水氧化性,减少了合金消耗,提高了转炉成分命中率。     

210t转炉滑板挡渣技术应用实践

介绍了新钢210 t转炉滑板挡渣与红外下渣检测技术改造及实际应用情况,并与目前常用挡渣方式进行对比分析,结果表明:转炉滑板挡渣成功率大于99.5%,出钢下渣厚度控制在50mm以下,转炉下渣及回磷量平均减少45%,取得了良好的经济效益。     

典型转炉出钢挡渣技术发展现状

控制转炉出钢过程中的下渣量一直是冶金领域的研究重点。本文主要介绍了转炉出钢挡渣技术的发展，并重点分析了三种典型的挡渣技术，即滑板挡渣法、气动挡渣法以及挡渣棒挡渣法的工艺特点和应用效果。滑板挡渣技术利用上滑板与下滑板之间的流钢孔错位，从而达到控渣出钢的目的，具有滑板开闭迅速、不受出钢口寿命和炉渣粘度的影响、与下渣检测技术配合可以实现转炉一键式自动出钢的特点，该技术挡渣成功率可以达到99%以上，炉下钢包渣厚可以稳定控制在50 mm以下，效果最佳；气动挡渣技术可以通过插入出钢口的喷嘴喷出高压氮气射流，从而将炉渣挡回转炉内，该技术是无形挡渣技术的一种，具有运行成本低、效果佳的优点，但是其设备故障率偏高，同时会降低出钢口的使用寿命，故在国内未得到普及推广；挡渣棒挡渣主要采用导向杆导入出钢口方式，确保挡渣塞能够准确到达出钢口位置，从而达到挡渣的目的，该技术具有操作简单、设备投资低、效果较好等优点，在国内应用最为广泛。     

滑板挡渣技术对转炉成本的影响

随着滑板挡渣技术在转炉炼钢工艺中优势的凸显,被越来越多的钢铁企业采用,尤其是品种比较高的钢铁企业,该技术让生产高附加值品种钢时,对P、S等有害元素和夹杂物控制的苛刻要求变得可控.滑板挡渣技术优势明显,但转炉耐材成本的增加让钢铁企业利润空间缩小.本文通过宣钢150 t转炉滑板挡渣技术投入前后冶炼数据的对比,详细分析滑板挡...     

滑板挡渣技术在包钢240t转炉上的应用

通过对转炉下渣过程的分析,系统对比了各挡渣方式的工作原理及其效果。滑板挡渣是基于大包滑动水口的控流系统,通过滑动滑板和固定滑板之间孔洞的位错运动,实现了对前期渣和后期渣有效的控制。滑板挡渣的成功率达到100%,转炉下渣量可以控制在60 mm左右,钢包回磷平均控制在0.000 5%以内,提高了钢水的洁净度,为生产成高附加值的钢种和降低生产成本奠定了良好的基础。     

Identification and changes in prejudice and in authoritarianism.

Ss "were first given the F Scale and a measure of anti-Negro prejudice… . Four weeks later they read a case history of a person who was prejudiced and authoritarian. Half of the subjects were told that the person in the case history was similar to themselves in background and objective personal characteristics. The other half… that the person was dissimilar to them. Three weeks later the F Scale and the anti-Negro prejudice scale were readministered. It was found that those low in prejudice at the first administration became more prejudiced but only if they were told the case history was about someone like themselves… . These results were interpreted in terms of the social support for suppressed 'wrong' feelings and in terms of the pressures to achieve cognitive consistency in one's self-concept." From Psyc Abstracts 36:04:4GD65S. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

MPD and DNA bending in crystals and in solution

Bending of 15 to 24 degrees is observed within crystal structures of B-DNA duplexes, is strongly sequence-dependent, and exhibits no correlation with the concentration of MPD (2-methyl-2,4-pentanediol) in the crystallizing solution. Two types of bends are observed: facultative bends or flexible hinges at junctions between regions of G.C and A.T base-pairs, and a persistent and almost obligatory bend at the center of the sequence R-G-C-Y. Only A-tracts are characteristically straight and unbent in every crystal structure examined to date. A detailed examination of normal vector plots for individual strands of a double helix provides an explanation, in terms of the stacking properties of guanine and adenine bases. The effect of high MPD concentrations, in both solution and crystal, is to decrease local bending somewhat without removing it altogether. MPD gel retardation experiments provide no basis for choosing among the three models that seek to explain macroscopic curvature of DNA by means of microscopic bending: junction being, bent A-tracts, or bent general -sequence DNA. Crystallographic data on the straightness of A-tracts, the bendability of non-A sequences, and the identity of inclination angles in A-tract and non-A-tracts B-DNA support only the general-sequence bending model. The pre-melting transition observed in A-tract DNA probably represents a relaxation of stiff adenine stacks to a flexible conformation more typical of general-sequence DNA.     

Research and teaching in social and preventive medicine and in public health

Both public health and social and preventive medicine are characterised by the common goal of promoting, maintaining and improving health and preventing disease, and both are concerned with a population-related, preventive and environmental perspective. But whereas public health is interdisciplinary and goes far beyond the medical focus, social and preventive medicine is medically based and forms a bridge between public health and medical practice. Research in a department of social and preventive medicine serves to support preventive and medico-social activities in medical practice as well as in public health. This is illustrated by results from research conducted at the author's department during the last twenty years. Examples are research in support of smoking cessation activities, and research used for the planning of care for the elderly. Both the research and the teaching activities of the department take into account the population focus of public health as well as the focus on individual medicine in clinical practice.     

Cholestatriene and ergostatetraene as in vivo and in vitro membrane and lipoprotein probes

The fluorescent cholesterol analogues, cholesta-5,7,9(11)triene-3-beta-ol (I) and ergosta-5,7,9(11)-22-tetraene-3-beta-ol (II), have been shown to be readily incorporated by various tissues and lipoproteins in rabbits maintained on diets supplemented with these fluorophores. Human erythrocytes and lipoproteins were also found to incorporate I and II in vitro under physiological conditions. The thermotropic behavior of the lipoproteins and erythrocyte membranes labeled with sterols I and II was evaluated using temperature-dependent fluorescence polarization and/or fluorescence intensity spectra. Erythrocyte ghosts, fluorescently labeled in vivo (rabbit) or in vitro (rabbit and human), were found to undergo a reversible thermally induced transition at 24 +/- 2 degrees C. A similar transition occurring at higher temperatures was also observed in fluorescently labeled human and rabbit LDL particles. Furthermore, the transition temperatures and relative microviscosities of the in vivo labeled rabbit LDL particles were found to be dependent upon the amount of sterol present in the rabbits' diet. No evidence of a similar thermotropic transition was observed in any of the HDL particles. These results are discussed in terms of a thermotropic reordering of cholesterol clusters existing in the erythrocyte membrane and of the cholesteryl ester core present within the low density lipoprotein particle.     

Differences and similarities in adjuvant chemotherapy in mouse and man

Supernatants obtained after incubation of tumor patient lymphocytes with the homologous tumor-associated antigen (TAA) elicit adherence inhibition in normal guinea pig peritoneal cells. From 37 tested patients with different carcinomas, the supernatants of 30 caused more than 10 per cent adherence inhibition (breast cancer 11/11, lung cancer 7/8, colon cancer 6/7, stomach cancer 6/11). Besides 40 healthy blood donors were tested to a panel of TAA. There was a reactivity more than 10 per cent only in 2 cases. The supernatants of 14 patients with nonmalignant disorders produced adherence inhibition more than 10 per cent in 2 cases. By incubation of tumor patient lymphocytes with the human encephalitogenic protein the supernatants of 19/27 patients elicited a positive reaction. The results suggest that anti-tumor immunity can be detected in an indirect heterologous adherence inhibition system.     

Protein phosphorylation and taurine biosynthesis in vivo and in vitro

Taurine is known to be involved in many important physiological functions. Here we report that both in vivo and in vitro the taurine-synthesizing enzyme in the brain, namely cysteine sulfinic acid decarboxylase (CSAD), is activated when phosphorylated and inhibited when dephosphorylated. Furthermore, protein kinase C and protein phosphatase 2C have been identified as the enzymes responsible for phosphorylation and dephosphorylation of CSAD, respectively. In addition, the effect of neuronal depolarization on CSAD activity and 32P incorporation into CSAD in neuronal cultures is also included. A model to link neuronal excitation and CSAD activation by a Ca2+-dependent protein kinase is proposed.     

Chemo- and baroresponses differ in African-Americans and Caucasians in sleep

To determine sleep effects on baro- and ventilatory responses to transient chemo- and barostimulation in African-Americans and Caucasians, 26 nonobese normotensive young subjects (13 African-Americans and 13 Caucasians) were studied awake and in non-rapid-eye movement (NREM) and rapid-eye-movement sleep during induced transient hypoxemia (N2), hypertension (phenylephrine, PE), and concomitant hypoxemia and hypertension (N2 + PE). Arterial blood pressure was recorded by plethysmographic volume clamp, minute ventilation by pneumotachograph, and arterial O2 saturation by pulse oximeter. For all subjects, chronotropic baroresponse (Deltapulse interval/Deltasystolic blood pressure, where Delta is change) increased with NREM sleep (P = 0.007). Baroresponse slope was greater in Caucasians than in African-Americans (ANOVA, P = 0.02). Hypoxemic ventilatory response (Deltaminute ventilation/Deltaarterial O2 saturation) was greater in African-Americans than in Caucasians in NREM sleep (P = 0.01), as was hypoxemic attenuation of baroresponse (N2 + PE, P = 0.03). These data suggest sleep-related differences in arterial chemo- and baroreceptor responses in normal young African-Americans and Caucasians, which may have implications concerning development of systemic hypertension.     

Interaction in systems Wc-Ni-Al and Wc-NiTi in sintering and impregnation

Translated from Poroshkovaya Metallurgiya, No. 5(317), pp. 77–80, May, 1989.     

Photoreactivation in bacteria and in skin

In many procaryotic and eucaryotic cells, photoreactivating enzyme mediates light-dependent repair of UV-induced damage: the enzyme binds to a pyrimidine dimer in DNA, and, on absorption of a photon (300-600 nm), specifically monomerizes the dimer, thus repairing the DNA. Photoreactivating enzyme has been found in human tissues and human cells in culture; human cells in culture can photoreactivate cellular dimers, and can mediate photoreactivation of Herpes (human fibroblasts) and Epstein-Barr virus (human leukocytes). Measurements of pyrimidine dimer formation and repair in human skin indicate that detectable numbers of dimers are formed at 1 minimal erythemal dose, that the dimers are rapidly removed in skin kept in the absence of light, and they are more rapidly removed when the skin is exposed to visible light.