ML15Al冷镦钢盘条的试制

介绍了采用氧气顶底复吹转炉-LF炉精炼-方坯连铸-高线轧制生产ML15Al冷镦钢盘条的生产工艺.通过对化学成分合理设计及制订适合本厂的冶炼、连铸、轧制工艺,采用Ca处理技术和全程保护浇铸技术相结合的有效措施,解决了浇铸含Al冷镦钢中包水口易堵塞的技术难题.生产的冷镦钢盘条,其产品质量完全符合GB/T6478-2001标准要求,并且获得了用户的好评.     

Practice of technologies of ML08Ai cold heading steel production at Rizhao Steel

介绍了ML08Al冷镦钢在炼钢过程中的控制及生产情况,包括转炉冶炼过程中合金的选择,硅质量分数控制,吹氩站渣脱氧以减轻精炼炉的脱氧造白渣的压力,严格控制成分等。这些措施解决了连铸时水口堵塞问题,实现了ML08Al冷镦钢的批量生产。     

日钢ML08Al冷镦钢炼钢工艺实践

介绍了ML08Al冷镦钢在炼钢过程中的控制及生产情况,包括转炉冶炼过程中合金的选择,硅质量分数控制,吹氩站渣脱氧以减轻精炼炉的脱氧造白渣的压力,严格控制成分等。这些措施解决了连铸时水口堵塞问题,实现了ML08Al冷镦钢的批量生产。     

SWRCH22A冷镦钢脱氧过程中非金属夹杂物生成热力学及工业实践

文中通过热力学软件FactSage 7.0和工业实践,对1 873 K下SWRCH22A冷镦钢脱氧过程中非金属夹杂物生成热力学进行研究.计算结果表明,当冷镦钢中[Al]含量增加到2×10-6以上时,平衡时钢中对应生成液态夹杂物、MnO·Al2O3和Al2O3,表明冷镦钢出钢过程应先加铝再加锰以降低精炼渣的氧化性.当冷镦钢中的[Mg]含量超过0.5×10-6时,钢中夹杂物由Al2O3转变为MgO·Al2O3;当钢中的[Mg]含量超过约9×10-6时,钢中夹杂物主要为MgO;随着钢中[Al]含量的提高,生成尖晶石夹杂物所需的最小[Mg]含量逐渐增大.当冷镦钢钢液中[Ca]含量超过约1.3×10-6时,钢中生成的夹杂物主要为液态钙铝酸盐;当钢液中的[Ca]超过约13×10-6时,钢中开始生成固态CaO夹杂物.冷镦钢中形成液态钙铝酸盐夹杂物所需的最小[Ca]含量随着钢中[Al]含量的提高逐渐增大.实验检测和热力学计算结果基本吻合,此外,研究发现,纯铁液的脱氧热力学与冷镦钢差异较大,因此,不能采用纯铁液的脱氧热力学指导冷镦钢生产实践.     

湘钢含铝冷镦钢的开发

介绍了湘钢含铝系列冷镦钢的研究开发情况以及产品质量的控制措施。从测试的力学性能看，能满足用户要求，开发的四个品种是成功的。     

含铝冷镦钢塞棒侵蚀原因分析与改进

 针对含铝冷镦钢在浇铸过程中的塞棒异常侵蚀问题,通过塞棒基体成分分析、塞棒侵蚀层的元素分布观察以及热力学计算,探究了含铝冷镦钢生产过程中塞棒侵蚀的成因,并提出相应的改善措施。结果表明,钢中高质量分数的钙与耐火材料中的Al2O3、SiO2、C发生反应,生成低熔点钙铝酸盐或硅铝酸盐以及Al2O3-C质塞棒本身材质中C＋SiC的质量分数过高是造成含铝冷镦钢浇铸过程中塞棒严重侵蚀的主要原因,通过规范钙处理工艺、更换镁碳质塞棒等措施,能够显著改善塞棒的异常侵蚀问题,塞棒的使用寿命由286～824 min提升至460～1 020 min,平均使用寿命由原来的495 min上升至802 min。     

ML08Al冷镦钢连铸坯中夹杂物的研究

利用转炉冶炼生产ML08Al冷镦钢，生产过程中通过冶炼工艺的优化，改善了钢中非金属夹杂物的形态和行为，提高了钢的质量。同时还特别对连铸坯进行了必要的检测分析，并对ML08Al冷镦钢连铸坯中非金属夹杂物的形态与行为做了深人的研究。提出了改善产品质量的措施和提高钢的纯净度的手段和方法。     

提高含铝冷镦钢钙收得率工艺研究

目前冶炼含铝冷镦钢时主要通过喂入钙线的方式,对钢水中脱氧产物Al2O3夹杂物进行变性处理,以改善钢水可浇性,减少钢水堵塞水口的情况发生。文章通过冶炼低硅含铝冷镦钢时,对渣层厚度、喂丝高度、喂丝深度和喂丝速度等方面进行研究,提高钙收得率,以达到最佳的钙处理效果,保证钢水可浇性的同时降低冶炼成本。     

冷镦钢质量控制技术

紧固件的加工通常以冷镦钢为原材料，冷镦钢的质量对紧固件加工过程和产品质量有着非常重要的影响。分析了影响冷镦钢质量的关键因素、冷镦开裂原因和压缩比对冷镦性能的影响，对国内外冷镦钢在显微组织性能等方面做了比较，最后探讨了冷镦钢未来发展方向。     

SWRCH18A冷镦钢生产实践

以SWRCHl8A钢为例介绍了湘钢二炼钢厂含铝冷镦钢的生产工艺。通过对铁水预处理、转炉冶炼终点控制、吹氩站成分调整、钢包炉钙处理、连铸保护浇铸和防止水口堵塞等工艺过程进行研究和技术攻关，摸索出了较为成熟的含铝冷镦钢的生产工艺。     

Evolution of the epidemic process as a form of solution to its internal contradictions

The author formulated the main contradition of the epidemic process consisting of contradiction between the interaction of the motive forces of the epidemic process, since this contradiction at the same time served as the imperative condition of the origination and as the cause of the subsequent arrest of the spread of infection. The main contradiction of the epidemic process is expressed in reduction of the number and limited activity of the sources of infection, attenuation or arrest of the mechanism of transmission of the causative agents, formation of immunity in the population, the appearance of hereditary resistance in the hosts to the causative agent of the infection. The action of the principal internal contradiction of the epidemic process in the course of evolution conditions genetic variability of the causative agents of the infectious diseases, intensification of the mechanisms of excretion of the parasites from the host organism, and increase of their resistance in the external environment, formation of latent forms of infection.     

Model system of binaural hearing. III. Binaural processing of information about short sounds

A model of neuronal structures of the medial superior olivary nuclei and inferior colliculus performing the determination of the direction on the source of the short (shorter than 10 ms) sound signals is presented. In the model the difference between the moments of the arrival of the two informational messages formed on the stage of monaural information processing is calculated. The result of this calculation is the firing probability of the primary detector (the neuron of the medial superior olivary nucleus). Because of the internal noise the curve of this probability as a function of the direction on the source is smoothly sloped. The estimation of the direction is the result of the statistical processing of the responses of the primary detectors ensemble. The direction on the source of sound is coded by a position of the secondary detector (the neuron of the inferior colliculus) on the direction "scale".     

STG-12变辊距型钢矫直机的设计计算

针对变辊距矫直机具有不同于恒辊距矫直机的结构特点 ,给出变辊距型钢矫直机辊数、辊距的确定方法 ,并计算出各辊的弯曲力矩及矫直力 ,最后求得设备电机功率。通过设备的具体运行证明 ,变辊距结构对改善设备的受力状况及提高型钢矫直质量十分有利     

连铸方坯中心线凝固行为波动现象及变化规律

连铸坯中心线区域钢液的凝固行为与中心偏析缺陷的形成及控制密切相关。基于中碳钢连铸方坯纵断面的实际凝固组织,以中心偏析点内部二次枝晶间距计算局部冷却速率,揭示了铸坯中心线局部冷却速率的波动特征。结合连铸三维凝固模型,研究了铸坯中心线固相率波动引起局部冷却速率波动并最终影响铸坯中心组织和性能的均匀性的机理;对不同工况铸坯中心线固相率和局部冷却速率波动的周期性进行了分析对比,提出了连铸坯凝固终点位置的周期性波动机理并得到了不同拉速下凝固终点波动距离的判断方程,对于所选连铸方坯,凝固终点波动距离为25.0～27.5 mm;在此基础之上,研究了拉速对中心线固相率波动程度的影响规律,并分析了凝固终点波动距离变化对末端电磁搅拌(final electromagnetic stirring, F-EMS)和轻压下(mechanical soft reduction, MSR)作用均匀性的影响。结果表明,拉速由1.8 m/min提高至2.4 m/min后,虽然液相穴长度增加可能增加整体偏析程度,但铸坯中心线固相率波动程度降低了20%,这有利于减轻中心线偏析沿拉坯方向的波动性,提高铸坯中心质量的均匀性。并...     

Networking for nurses in today''s turbulent times

Craniocerebral injuries involve changes in the vascular plexuses and ependyma of the ventricles, and the severity of these changes varies, depending on the duration of the posttraumatic period and severity of the injury. Analysis of the time course of pathomorphological changes in the cerebral ventricular structures extend our notions on the role and impact of liquor circulation in the pathogenesis of craniocerebral injury. Structural changes in the vascular plexuses may disorder the function of the blood-liquor barrier and promote the development of hydrocephalus. Changes in the structure of the ependymal membrane may involve dysfunction of the liquor-encephalic barrier of the inner surface of the brain and promote the development of brain edema.     

Functional analysis of patients who have had a modified Van Nes rotationplasty

Electromyographic analysis of gait in eight patients who had had a modified Van Nes rotationplasty was performed to compare the activity of the flexors and extensors of the ankle on the side of the operation with that of the flexors and extensors of the knee on the normal, contralateral side. The resemblance in the activity of the extensors was more pronounced than that of the flexors. In three patients, the angle of flexion of the knee throughout the gait cycle was the same on the side of the rotationplasty as on the normal side. There was more symmetry in the swing phase than has been reported for patients who have had an above-the-knee amputation. The strength of the dorsiflexors of the ankle on the side of the rotationplasty was 68 percent and that of the flexors was 71 per cent when compared with that of the muscles of the normal ankle.     

机床液压系统常见故障及使用维护方法分析

机床液压系统通常,下含义判断产生故障的原因。本文通过对机床液压系统常见故障进行分析,从机床液压系统振动和噪音、液压系统的冲击、液压系统中的“爬行”、液压泵出现吸空情况、液压系统温度上升五个方面进行介绍,提出诊断方法,并且介绍机床液压系统的使用和维护注意事项,希望可以帮助相关工作人员排除故障问题,保障机床液压系统的正常运作。     

Epidemiological assessment of the system of indices characterizing the quality of vaccine preparations

The authors discuss the methodology and the method of formation of the medico-technical requirements to newly-elaborated or modified vaccine preparations. The following are considered among the principal parameters responsible for the formation of the quality of the vaccines: the prophylactic activity, the extent of the injurious effect, the technological and the exploitation properties. A close association of these parameters in the determination of the quality of the vaccine and the dependence of the efficacy of its use on the character of the epidemic situation was shown. A possibility of using the method of calculation of the efficacy of immunization for detection of the main (leading) parameters of the quality of the vaccine elaborated which should be used in composing the medico-technical requirements. It is emphasize that one of the principal directions of the investigations is the elaboration and the assessment of the correctness of the immunological and laboratory methods of standardization and control of the methods of objective measurement of the parameters forming the quality of the vaccine preparations.     

采场充填料浆流动与离析规律的试验研究

为研究采场充填料浆流动规律及充填料浆离析分层对充填体强度的影响规律,开展了充填料浆流动相似模拟试验及采场原位充填体力学强度测试试验,研究结果表明：单点下料时充填料浆流动终态坡面趋向于正态分布。流动过程中充填料浆产生离析分层现象,主要表现为充填体物料的粒径沿料浆流动方向呈先增大后减小的趋势,充填体强度沿料浆流动方向呈先减小后增大再减小的倒转“S”形趋势。采场原位充填体强度在下料口附近与标准试块强度接近,在采场中间位置附近的充填体强度最小,在距离下料点采场长度7/10左右的位置充填体强度达到最大值。研究成果能够为充填采场下料管的数量及位置设计提供依据,从而保证充填体的整体质量。     

矿山地质环境调查评价技术方法的研究

党的十八大以后,生态文明建设作为中国特色社会主义建设的重要组成部分,对生态环境保护和治理提出了高标准,而矿山地质环境保护与治理是生态文明建设的主要内容之一,保护与治理工作开展前必先查明矿山地质环境现状。调查评价作为前期工作的主要手段之一,调查的范围、精度与评价技术方法的科学性、创新性,对矿山地质环境保护与治理工作成效起着决定性作用。