AZD20—13型锅炉除尘系统改造

介绍了锅炉除尘系统的改造过程及效果，大大提高了除尘效率，达到了节约资金，减少污染的目的。     

鄂钢2＊75m^2烧结工程除尘系统设计

本文介绍了鄂钢７５ｍ＾２烧结工程除尘系统设计的特点及运行中出现的问题和处理方法，并进一步提出了解决熔剂破碎除尘管道堵塞问题的设想。     

铅锌烧结电除尘器设计与应用

本文针对铅锌精矿烧结机作业特点，产生烟气条件及烟尘性质，较详细地分析和论述了电除尘器总体设计，参数确定，极板形式，极间距和结构特点，同时介绍了设备调试与生产运行情况。     

攀钢1号高炉出铁场除尘治理技术

对攀钢1号高炉出铁场除尘治理技术进行了阐述，提出了铁口悬臂烟罩＋铁口侧吸罩＋屋顶组合式烟罩的综合捕集方式，有效地治理了出铁场的污染烟尘，取得了良好的环境效益和经济效益。     

选矿厂粗破碎卸矿处除尘的实践

本文介绍了本钢南芬铁矿粗破碎卸矿处除尘的设计，从尘源控制，风量确定和净化设备选择，比较成功地解决了大面积扬尘点除尘的难题，使车间粉尘浓度和排放粉尘浓度均低于国家标准，实践证明，该项除尘设计取得了较好的环保和社会效益。     

转炉湿法除尘设计的几个关键问题

通过对二炼钢厂３０ｔ转炉除尘改造成功设计的总结，对转炉湿法除尘的关键性问题做了探讨。     

Metamex滤料与高炉煤气脉冲布袋除尘

Ｍｅｔａｍｅｘ滤布和脉冲布供除尘技术相结合用于煤气除和目前广泛使用的反吹风大布袋相比，产生了质的飞跃。脉冲布袋除尘技术不仅用于中小高炉，而且具备了用于６００－１０００ｍ＾３或更大高炉的条件，前景看好。     

8号高炉除尘箱体设计分析

高炉煤气采用干法布袋除尘技术具有除尘效率高、投资省、占地面积少、减少二次污染等特点。柳钢自1994年4号高炉设计采用干法布袋除尘以来，逐步完成了全部高炉干法布袋除尘改造，并且使该项技术逐步得到进步、扩展、完善。以除尘箱而言，由最初的一座高     

干式布袋除法技术在大容积高炉除尘系统的应用

介绍了干式布袋除尘技术在攀钢４＃高炉系统上的成功应用，分析了制约干式布袋除尘技术应用的关键环节上存在的问题，提出了改进措施。     

小型高炉煤气除尘系统选择的探讨

对两座高炉煤气布供袋除尘器及湿法除尘装置的使用情况进行了总结分析，认为对于小型高炉煤气除尘系统的选择，应首先考虑是高炉入炕料精否。当入炉料不清，特别是熟料率低时，不宜选用布袋除尘器。     

戈塘金矿房柱法开采围岩稳定性分析

戈塘金矿矿体厚度变化较大,地质条件复杂。为科学设计井下采场参数,分析采空区顶板的破坏机理及矿柱的承载机理,指导矿山安全生产,以戈塘金矿为研究对象,设计了采场参数,分析了采场围岩稳定性。通过理论计算,采用房柱法开采时,推荐矿柱尺寸为3 m×3 m,矿房跨度不超过10 m;利用有限元软件Phase2对留设不同宽高比的矿柱时采场围岩的稳定性进行了数值模拟分析。结果显示:矿柱内部出现应力集中,采空区顶底板、岩帮为应力降低区域;随着矿柱宽高比的增大,采空区边界附近的应力水平和位移降低,矿柱内应力集中得到缓解,变形量降低。综合分析认为,矿柱宽高比对采场围岩稳定性有一定影响,保持矿柱宽高比约为0.500,可以较好地维持采场稳定。     

等温压缩对高强度汽车钢WHT1300HF的马氏体相变及微观组织的影响

通过等温形变研究了形变参数(形变温度、形变速率、形变量)对高强度汽车钢WHT1300HF的微观组织转变和形貌的影响规律。研究结果表明:增加奥氏体等温形变量,有利于铁素体的缺陷形核,促进了形变奥氏体向铁素体转变;奥氏体的形变强化导致马氏体相变阻力增大,马氏体相变开始温度(Ms)下降,细小晶粒数量和小角度晶界数量增多;增加奥氏体等温形变(40%)速率能同时促进马氏体和铁素体相变,但马氏体体积分数和小角度晶界数量减少,细小晶粒数量略有提高;降低等温形变温度加剧奥氏体的形变强化,导致Ms温度下降,马氏体体积分数、小角度晶界比例减少,细小晶粒数量增多,铁素体含量明显增加。     

Dermomyotomal origin of the ribs as revealed by extirpation and transplantation experiments in chick and quail embryos

To elucidate role of the dermomyotome in the formation of the axial skeleton, we performed extirpation and transplantation experiments on the dermomyotomes in chick and quail embryos. When the thoracic dermomyotomes of chick embryos were removed, the intercostal muscles and the distal ribs were deficient, while the proximal ribs were more or less normal. Quail tissues including the dermomyotome, the ectoderm and the medial edge of lateral plate, were transplanted to replace chick dermomyotomes. In these chimeras, the ribs, which would be deficient without the back-transplantation, were recovered. The cells of the recovered part of the ribs as well as the intercostal muscles were derived from the quail transplants. These findings suggest that the distal rib originated from the dermomyotomes and not the sclerotome as previously believed. To localize the origin of the distal rib further, we removed restricted regions of the dermomyotomes along the mediolateral and the rostrocaudal axis. The more lateral the part of the dermomyotomes that we removed, the more distal the part of the ribs affected. On the contrary, when the rostral and caudal edges of the dermomyotomes were removed, only the vertebral ribs showed extensive deficiencies while removal of the middle part between the edges caused less deficiency. The sternal ribs were not deficient in either case, but were extensively affected when the entire lateral edge of dermomyotomes was included in the region removed. We conclude that the lateral edges of the dermomyotomes are the primordia of the sternal ribs, and the rostral and/or caudal edges of the medial part of dermomyotomes are the primordia of the distal part and not of the proximal part of the vertebral ribs.     

A method of estimating linear and angular accelerations in head impacts to pedestrians

In order to investigate the relationship between impact to the head and brain injury, we have developed a method, using information obtained from reconstruction of the collisions, of estimating the peak linear and angular accelerations of the head for pedestrian impacts on a vehicle. This information includes the location of the impact on the head, the impact velocity of the head, and the stiffness of the struck surface. In developing the method we assumed that the velocity of the head on striking the vehicle was the same as the velocity of the vehicle itself, that the force vector was normal to the surface of the skull, that the force-deflection curve characterising the combined response of the impacted surfaces was linear, and that the kinetic energy of the head immediately prior to impact was converted into strain energy in deforming the head and the vehicle structure. Only the loading phase of the impact was considered, there was no assumption of an elastic unloading phase. Using cadavers, the validity of these assumptions and hence the usefulness of the method were tested by comparing the estimates of peak linear acceleration with the results of 18 pedestrian-vehicle impact reconstructions. On average, the method underestimated the experimental values by about 15%, with a range of +/- 35%. The results from the application of this method are currently being used to study the relationship between the magnitude and direction of the impact to the head and the distribution and severity of the brain injury resulting from actual collisions.     

轧辊非均质特性对辊型电磁调控的影响分析

 轧辊作为辊型电磁调控技术的核心构件,在加工制造时必须进行热处理,改变轧辊表层组织形态,形成轧辊表面淬硬层,引起轧辊表层和芯部材料性能差异,而这种差异会对辊型电磁调控特性产生影响。为此,利用有限元软件MSC.MARC建立了电磁 热 力耦合轴对称模型,并依托辊型电磁调控试验平台对模型精度进行校核。在此基础上,依托模型分析了表面淬硬层厚度对辊型电磁过程中辊凸度、辊型曲线、接触面平均正压力及轧辊应力分布的影响。结果表明,表面淬硬层厚度对辊凸度、辊型曲线和接触面正压力的影响较小,但对轧辊应力分布有明显影响,特别是轧辊表面淬硬层中心区域。     

高端装备用轴承钢冶金质量性能现状及未来发展方向

针对滚动轴承特点、轴承钢类型以及国内外轴承钢差距,本文对国内外高端装备用轴承需求、国内外轴承钢品种、轴承钢生产装备与冶金质量、轴承钢热处理技术以及轴承钢质量性能评价技术等发展现状进行了综述,指出了国内外高端装备用轴承钢在冶炼流程的超纯净控制、新型热处理技术和新型轴承钢研发对提升轴承长寿命的巨大作用,提出了未来基于夹杂物...     

浅谈后张法有粘结预应力梁施工工艺

本文旨在更有效地利用高强钢材,弥补混凝土与钢筋拉应变之间的差距,把预应力运用到钢筋混凝土结构中去。亦即在外荷载作用到构件上之前,预选建立有内应力的混凝土,通过对预应力筋进行张拉、锚固、放松,借助钢筋的弹性回缩,使受拉区混凝土事先获得预压应力。当构件承受由外荷载产生的拉力时,首先抵消混凝土中已有的预压力,然后随荷载增加,才能使混凝土受拉而后出现裂缝,因而延迟了构件裂缝的出现和开展。     

Multiple-cracking phenomenon of the galvannealed coating layer on steels under thermal and tensile stresses

The multiple-cracking phenomenon of the Fe-Zn intermetallic coating layer on the hot-dip galvannealed (GA) steels under thermal and tensile stresses was studied experimentally by tensile tests and analytically by means of the finite-element analysis. The multiple cracking of the coating layer had occurred in the as-supplied samples, and it progressed with increasing applied strain. Based on the calculated dependence of the stress of the coating layer on the crack spacing and applied strain, the multiple cracking in the as-supplied samples was accounted for by the thermally induced residual stress, and the further multiple cracking with increasing applied strain was accounted for by the increased stress of the coating layer. The experimentally observed decrease of the average crack spacing with increasing applied strain was described well, and the tensile strength of the coating layer was estimated to be 260 MPa, by application of the calculated relation between the increased stress of the coating layer and applied strain. The influences of the thickness of the coating layer and the substrate material on the multiple cracking were discussed based the stress analysis. It was revealed that the thinner the coating layer and the higher the flow stress of the substrate, the higher the stress of the coating layer becomes and, therefore, the smaller the crack spacing becomes.     

Diagnostic Analysis of the Evolution Mechanism for a Vortex over the Tibetan Plateau in June 2008

Based on the final analyses data (FNL) of the Global Forecasting System of the NCEP and the observational radiosonde data,the evolution mechanism of an eastward-moving low-level vortex over the Tibetan Plateau in June 2008 was analyzed.The results show that the formation of the vortex was related to the convergence between the northwesterly over the central Tibetan Plateau from the westerly zone and the southerly from the Bay of Bengal at 500 hPa,and also to the divergence associated with the entrance region of the upper westerly jet at 200 hPa.Their dynamic effects were favorable for ascending motion and forming the vortex over the Tibetan Plateau.Furthermore,the effect of the atmospheric heat source (Q1) is discussed based on a transformed potential vorticity (PV) tendency equation.By calculating the PV budgets,we showed that Q1 had a great influence on the intensity and moving direction of the vortex.In the developing stage of the vortex,the heating of the vertically integrated Q1 was centered to the east of the vortex center at 500 hPa,increasing PV tendency to the east of the vortex.As a result,the vortex strengthened and moved eastward through the vertically uneven distribution of Q1.In the decaying stage,the horizontally uneven heating of Q1 at 500 hPa weakened the vortex through causing the vortex tubes around the vortex to slant and redistributing the vertical vorticity field.     

Nature of the curves of the cranial vault and their relationship with various brain structures

A radiometric investigation for various angles of two dry craniums and of the encephalographic or cerebral arteriographic pictures of 250 subjects has revealed the following facts: The architectural lines of the dome of the skull found by orthogonal projection of the profile, from the front, and in vertical projection, are hyperbolic spirals starting from the base of the skull and converging on the sphenoid. These lines join up in the parietal region forming a hyperbole. The frontal spiral is a simple hyperbolic spiral. The temporal spiral is of the lituus type. The axes of these lines converge in a frontal plane on the epiphysis. The axis of the parietal hyperbole on a projection of the profile passes through the epiphysis and is followed by the parietal artery. Central cranio-encephalic formations follow the same spiral path. The contour of the upper edge of the cerebellum is a lituus spiral. The outline of the lower part of the cerebellum is a simple hyperbolic spiral. The right side of the polar origins of a spiral plotted in the plane of the insula coincides with the right side of the opercula. It can always be plotted, in theory, and forms an angle of 22 degrees 30' with the right side of the median frontal spiral. It cuts the axis of the parietal hyperbole at the apex of the insular triange. The bissector of the angle formed by the two right sides of the polar origins bissects the axis of the parietal hyperbole at a point corresponding to the epiphysis. The temporal hyperbolic lituus spiral has its focal point under the anterior, clinoid, at the junction of the segments CII and CIII of the carotid siphon the curve of which follows the convolutions of the temporal spiral. The right side of the polar origins of this curve indicates the mean direction of the posterior cerebral. The contours of the corpus callosum are homothetic with those of the dome of the skull as far as the axis of the parietal hyperbole. The frontal and parietal curves converge according to four types in the main Pacchionian granulations. The sections of the frontal spiral are often marked by bone abnormalities on the internal table. This analytic test is invariably valid whatever the constants of the spirals or the eccentricities of the hyperboles. Combinations between spirals with different constants and hyperboles of various eccentricities amount to very many types which call for separate study.