Structure-function correlations in the human medial rectus extraocular muscle pulleys

PURPOSE: Fibroelastic pulleys function like the trochlea to fix the position and pulling direction of the recti extraocular muscles within the orbit. This study characterized the fine structure of the human medial rectus muscle pulley. METHODS: Human medial rectus muscle pulley tissue was dissected at autopsy, immersed in aldehyde fixative solution, and processed for and examined with light and electron microscopy. RESULTS: Pulley structure were located within posterior Tenon's fascia, closely surrounding the medial rectus muscle. Pulleys were comprised of a dense collagen matrix with alternating bands of collagen fibers precisely arranged at right angles to one another. This three-dimensional organization most likely confers high tensile strength to the pulley. Elastin fibrils were interspersed in the collagen matrix. Fibroblasts and mast cells were scattered throughout the relatively acellular and avascular collagen latticework. Connective tissue and smooth muscle bundles suspended the pulley from the periorbita. Smooth muscle was distributed in small, discrete bundles attached deeply into the dense pulley tissue. CONCLUSIONS: Fine structural observations confirm the existence and substantial structure of a pulley system in association with the medial rectus extraocular muscle. The presence of pulleys must be considered in models of the oculomotor plant. The cytoarchitecture and placement of pulleys suggest that they are internally rigid structures and are consistent with the idea that they determine functional origins for the extraocular muscles. However, the nature of the connective tissue-smooth muscle struts suspending the pulley system to the orbit supports the notion that the pulley position, and thus the vector force of the eye muscles, may be adjustable.     

Blood lactate concentrations during incremental exercise in subjects with sickle cell trait

The need for lateral release or "venting" of the A2 and A4 pulleys either to facilitate repair of the flexor tendon(s) or to allow free gliding of the repair(s) was examined in 126 consecutive zone 2 flexor tendon injuries within the tendon sheath and distal to the distal edge of the A2 pulley (zones 2A and 2B of Tang's classification) in which at least one flexor tendon had been completely divided. This study showed that 81 (64%) of these repairs required venting of one or the other pulley. It was necessary to vent the A4 pulley between 10 and 100% of its length in 71 (56%) of the fingers and to vent the distal edge of the A2 pulley by 4 to 10 mm in 10 (8%) of the fingers.     

WF5-40模具扁钢连轧机组离线模拟软件的开发

为了便于在现场实际生产前了解思是过程中的工艺参数及安全情况,地现场实际生产工艺进行离线模拟,为抚顺特种钢钢铁公司开发了离线模拟软件,该软件可计算轧制过程中各道 次各机架的变形力学参数（包括轧制宽展、帽速度、变形温度、变形抗力、轧制力、轧制力矩和功率等）进行设备校核,现场应用结果表明,该软件对ＷＦ５－４０模具扁钢的生产具有重要指导作用。     

Mental animation: Inferring motion from static displays of mechanical systems.

Analyzed reaction time (RT) and eye-fixation data to investigate how people infer the kinematics of simple mechanical systems (pulley systems) from diagrams showing their static configuration. It is proposed that this mental animation process involves decomposing the representation of a pulley system into smaller units corresponding to the machine components and animating these components in a sequence corresponding to the causal sequence of events in the machine's operation. Although it is possible for people to make inferences against the chain of causality in the machine, these inferences are more difficult, and people have a preference for inferences in the direction of causality. The mental animation process reflects both capacity limitations and limitations of mechanical knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

矿冶设备液压传动起重、升降机构分析

叙述了矿冶设备起重、升降机构采用机械传动、液压传动和气压传动的优缺点,重点说明了液压传动的特点。介绍了由增速滑轮组演变为油缸-链条（钢丝绳）倍速升降机构和由省力滑轮组演变为液压马达一链条倍力升降机构的工作原理和应用特点。     

热胶+冷胶修复撕裂钢芯胶带的新工艺

本文介绍了钢芯胶带热胶、冷胶及其特点,详细说明了热胶＋冷胶修补工艺在修复德兴铜矿撕裂钢芯胶带上的具体应用和取得的成果,阐述了这一工艺的安全、快速、质量可靠、成本低廉的特点,特别适用于大型钢芯胶带的撕裂修补。     

模具扁钢轧制除鳞工艺改进

通过对孔型优化及轧制工艺的改进,弥补设备自身能力的不足,有效改善模具扁钢的表面质量和外形尺寸,提高成材率。     

铝硅合金的液态模锻

本文阐述了铝硅合金液态模锻过程中施加压力对结晶组织和机械性能的影响,提出了合理选择工艺参数的原则,此外还讨论了液态模锻模具结构设计方面应考虑的特点。     

Seat belts: Changing usage by changing beliefs.

Tested a model to predict seat belt use, based on a linear combination of (a) beliefs about discomfort when wearing a seat belt and (b) beliefs about injury reducing effects of seat belts. 154 employees of a large steel company, nonusers of seat belts, were randomly assigned to 1 of 6 groups receiving one or a combination of the following treatments: (a) verbal information stressing the role of seat belts in reducing injury, (b) nonverbal practice in seat belt use, (c) verbal information irrelevant to seat belt use, or (d) no treatment. Groups receiving seat belt information had the most favorable posttest beliefs and displayed the greatest increase in seat belt usage, although the effects generally decreased over time. The Discomfort (D) factor and the model (D * E) were equally predictive, while the Effect (E) factor was predictive only at low values. A multiplicative model is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

天铁集团电子称重设备的应用与维护

介绍了天津天铁冶金集团电子称重设备的应用情况。阐述了电子皮带秤的结构配置、校验、维护、管理等方面的具体方法,使其在实际应用中保持了较稳定的运行精度,满足了商业贸易结算检斤计量设备的要求,完全达到了贸易结算皮带秤的技术标准。     

Black Creek Canal Virus infection in Sigmodon hispidus in southern Florida

Flexor pulleys in the hindpaw digits of twenty-eight adult mixed-breed dogs were reconstructed in order to investigate the influence, on the reconstruction, of the source of the autogenous tissue (intrasynovial compared with extrasynovial tendon) and the tension applied during the repair. The ipsilateral peroneus longus tendon was used to reconstruct the A2 pulley with an around-the-bone technique in twenty-one digits; the graft was sutured at a tension of 0.49, 0.98, and 1.96 newtons in seven digits each. The flexor digitorum profundus tendon of an adjacent digit was used to reconstruct the A2 pulley, at a tension of 0.98 newton, in seven additional digits. The contralateral digits were used as controls for all twenty-eight treated digits. The digits were tested in a custom apparatus designed to measure the frictional force generated between the reconstructed pulley and the tendon beneath it. The frictional force did not differ significantly (p > 0.5) among the three groups repaired with peroneus longus tendon; however, the average value was more than five times that produced in the contralateral, control digits. The average frictional forces created by the flexor digitorum profundus grafts were similar to those in the contralateral, control digits. Reconstruction with the flexor digitorum profundus at a tension of 0.98 newton produced significantly less frictional force (p < 0.05) than that produced by the peroneus longus graft at the same tension. This in vitro model of reconstruction of the A2 pulley demonstrated that tendon from an intrasynovial source (the flexor digitorum profundus) produced less frictional resistance to gliding of the tendon than did tendon from an extrasynovial source (the peroneus longus). This result is consistent with previously published findings that intrasynovial tendons may make better grafts than extrasynovial tendons for the reconstruction of gliding flexor tendons because of decreased friction and better healing qualities. Intrasynovial tendons may also make better grafts for the reconstruction of flexor pulleys.     

Development of Single‐Belt Strip Casting Simulator

Near‐net‐shape casting is one of the key technologies to improve process efficiency of steel production. Single‐belt strip casting is recognized as a promising technology for thin strip production because of the advantages like well‐controlled heat transfer rate, flexibility in production rate, compactness of equipment, and so on. In this study a newly designed simulator of the single‐belt strip casting process was developed. The simulator solidifies molten metal on the running solid metal bar with a groove for molten metal deposition pushed by a pneumatic cylinder. Capability of this simulator design was discussed by one‐dimensional numerical heat transfer analysis. It showed that a steel casting bar thicker than 40 mm was capable of casting test of 10 mm thick steel strip even if interfacial thermal resistance existed. Finally, the simulator was applied to the casting test of aluminum strip, and successfully estimated the variation of the interfacial heat flux from the solidifying strip to the casting bar.     

冷轧薄板卷取机助卷皮带受力分析及优化

通过对卷取机助卷器的运行情况和动力学特性进行研究,找出了生产冷轧薄板过程中助卷皮带张力和张紧缸压力之间的对应关系,提供了助卷皮带张力调整的理论依据,优化了助卷器的性能,延长了助卷皮带的使用寿命,提高了带钢的成材率,降低了冷轧薄板生产成本。     

高强度球扁钢感应加热有限元模拟与工艺优化

基于实际生产工况参数,利用ABAQUS有限元分析软件,对高强度球扁钢的感应加热过程进行二维模拟,模拟结果与实测结果基本一致。探究了线圈电流密度对球扁钢截面温度分布的影响,提出了球扁钢感应加热工艺参数优化方案。模拟结果的推荐工艺参数为：预热电流密度为7.0×106 A/m3,加热电流密度为8.5×106 A/m3。对优化工艺参数前后的高强度球扁钢进行显微组织和力学性能比较,结果表明,优化感应加热工艺参数后的高强度球扁钢具有更好的截面均匀性。     

太钢4350m~3高炉水渣系统吹扫装置的降耗改造

针对太钢4 350 m3高炉水渣系统皮带机头轮吹扫装置在生产过程中暴露出来的能耗较高的问题,对其机械结构进行降耗改造。根据实际生产设备,运用三维建模软件对其结构进行建模,给出了改造部位的结构模型图,并且已经运用到实际生产中。实践证明,这次技术改造不仅大大降低了能源消耗,直接降低了生产成本,而且提高了吹扫冲渣的能力。     

上黑龙江成矿带区域成矿特征

上黑龙江成矿带是我国重要的金属成矿带之一,是武警黄金第三支队当前重点的金矿地质勘查区,通过对区域成矿地质背景和成矿时代演化规律的研究,划分出中侏罗世中温热液型金矿床、晚侏罗-早白垩世火山岩型金矿床、晚侏罗-早白垩世斑岩型铜-金-银矿床3 个成矿系列,将上黑龙江成矿带进一步划分成了老沟-依西肯金-铜-钼、长缨金、二十一站-宝兴沟铜-金、富拉罕金4 个Ⅳ级成矿带,总结了成矿规律及找矿标志,对该区进一步地质找矿,具有一定的指导意义。     

湘钢126m2鼓风带冷机设计

针对湘钢二烧结厂一期带冷机存在的断链、台车变形、液压张紧失效、漏风、扬尘、积灰严重、冷却效率差等问题，介绍在二期带冷机设计中采取的改进措施。     

Tempering process of high strength and high toughness Cr- Mo- V bulb- flat steel

Aim at the problems that the heat treatment process of high strength and high toughness Cr- Mo- V bulb- flat steel was difficulty and the granular bainite was not fully decomposed, the influence of different tempering temperatures and tempering holding times on the microstructure and mechanical properties of high strength and high toughness Cr- Mo- V bulb- flat steel were studied by optical microscopy, SEM, TEM and mechanical property tests. The results show that the metastable granular bainite in the steel can be recovered and transformed to quasi- polygonal ferrite by tempering at temperatures above 600?? and holding for more than 2h. The large- sized and long- shaped M- A islands in the original microstructure are decomposed and transformed into granular M- A islands. With the increase of the tempering temperature, the granular bainite in the steel can be further decomposed to make the particles finer and more dispersed, which significantly improves the low- temperature toughness of the steel and obtains a good comprehensive performance. For this steel, the best heat treatment process to get good match of strength and toughness is tempering at 660-680?? and holding for 3. 0-3. 5h.     

昆钢转炉污泥处理系统的改造

昆钢第三炼钢厂针对带压机污泥处理工艺存在的问题，对粗颗粒分离机，浓缩沉淀池，压带机，加药系统等进行了技术改造，一举获得成功，污泥中铁金属得到１００％回收，处理后的水质ＳＳ〈２００ｍｇ／Ｌ，ＰＨ值控制在９以内，环境污染干净，效益显著，满足炼钢生产顺利进行。     

高精度扁钢轧制工艺技术及装备

介绍了抚顺特殊钢集团公司已投产的高精度扁钢生产线的工艺流程、引进奥地利GFM公司WF5-40轧机组的机械、液压、电控及工艺软件数学模型等技术。