VOD扒渣工位钢水罐重心变化浅析

通过三维零件模型的建立获得零件的重心及相关数据,核算120t钢水罐及转架在翻转过程中的重心变化,从理论土分析可能发生的事故原因,同时有针对性的采取整改措施。     

浅谈如何做好当前医院思想政治工作的思考

当前深化医改的工作重心已从政策设计转到任务落实,在此新形势下,只有适应变化的新特点,明确并认真实践创新的工作思路,思想政治工作才会被职工所接受.     

液压控制在钢包倾翻装置中的实现

在工业生产大型设备中，液压站是不可缺少的动力系统。而对液压设备及液压站系统的控制是其中的重心。对杭钢转炉厂铁水倾翻装置中液压站控制系统做了简单的分析，并对其PLC系统硬件配置等做了概要分析。     

稀土:价格回调 消费回暖

稀土产业一直以争夺定价话语权为重心,稀土价格的暴涨超出了下游用户的成本承受及转移能力,2011年来,市场需求持续低迷。在世界稀土产业发生深刻变化(供给多元化、产业一体化)的趋势下,中国稀土产业的工作重心更应放在稀土及稀土功能材料的本土化应用上。WTO稀土诉讼案将于年末裁决,业界普遍缺乏信心,有可能引发产业管理体系的变化。预计2013年单一稀土氧化物价格综合指数均值在2.8～3.0之间;国内消费量则上升至9万吨。通     

16m3渣罐倾翻过程分析

文章应用三维CAD软件对渣罐进行建模,计算了其在倾翻过程中的重心位置变化情况,分析了渣罐倾翻后不回位的原因。本文所得到的分析结果,为合理设计渣罐提供重要依据。     

计算转炉液体金属倾动力矩的新方法

转炉倾动力矩包括空炉力矩、液体金属倾动力矩和耳轴摩擦力矩。在转炉倾动过程中,耳轴摩擦力矩在出钢之前几乎没有变化;空炉力矩虽有变化,但由于炉体的重心位置不变,因而较易确定,其数值均可按计算公式求得。然而,液体金属的重心位置     

新形势下应加强高校学生党支部建设

高校学生党员工作是高校党建工作的重要组成部分,是思想政治工作的重要环节。针对目前高校学生党建工作的一些具体情况,就基层学生党建工作现状进行现象和问题分析,以期学生党建工作能够从方式、方法、工作重心以及时间、空间等诸多方面,突破固有模式,求创新、求拓展、求实效。     

宝钢COREX-3000铁口维护操作实践

阐述了宝钢COREX-3000装置开炉至今的铁口维护状况,通过采取包括调整炮泥和钻具以及操业调整等措施,铁口深度恢复至2400mm的安全水平。同时,分析了铁口深度历经变化采取措施的效果和机理,为今后铁口维护工作奠定基础。     

弯辊装置的故障分析与结构改造

精轧机组的工作辊,经常因为工作辊弯辊装置的液压锁紧缸动作异常,拖延精轧机组工作辊换辊时间,严重影响热轧厂的设备运转率.通过弯辊装置液压锁紧缸故障总结和工作辊弯辊装置原理、结构分析,对工作辊弯辊装置操作侧与传动侧液压锁紧缸进行改造.     

高压无功补偿装置的技术创新

通过分析多种投切电容器组开关电路，在改进部分电路的基础上开发出一种新型高压无功补偿装置。该无功补偿装置具备以下显著优点：可快速跟踪系统无功功率的变化，合闸时能有效避免电流冲击，分闸时能有效避免重燃，合闸和分闸主回路特性如同晶闸管的工作特性，但使用成本和能耗却比晶闸管低。     

Anticipatory postural adjustments in the back and leg lift

This study examined anticipatory postural adjustments in a dynamic multi-joint action in which a relatively fast voluntary movement is being executed while balance is maintained in the field of gravity. In a bi-manual whole body lifting task, the pickup of the load induces a forward shift in the position of the center of mass, challenging the dynamic balance regulation while simultaneously impeding the ongoing extension movement. We investigated whether anticipatory postural adjustments are an addition to a voluntary motor command or an inherent component of this command. Using a global mechanical analysis of the movement, we found that anticipatory postural adjustments are present in bimanual lifting, both in back lifting and leg lifting, and that lifting technique had a significant influence on the pattern of the adjustments. If the mass of the object was reduced unexpectedly, balance was disturbed in 92% of the mass-reduced trials. These findings suggest that the anticipatory postural adjustments to be performed are specified in advance such that the expected changes in the mechanical interaction with the environment are taken into account. The observations lend support to the hypothesis that the control of the observed anticipatory postural adjustments is an integral part of the control of the lifting movement itself. Consequently, the strict dichotomy in the control of posture and movement is being questioned.     

角型钢架整体吊装的实践

介绍了重19.525t、高62.5m的角型钢架重心、快绳拉力的计算、模拟起吊试验、吊装方案的确定、起重设备及辅助设施的选配和现场起吊程序制定的全过程。     

阳极板载运车提升卸载装置改进与优化

介绍了贵溪冶炼厂极板转运设备阳极板载运车提升卸载装置的组成及工作原理,并从提升卸载装置缺乏自由度、限位支架损坏摆动撞击、提升装置倾斜重力、硬性碰撞冲击四个方面分析了提升卸载装置产生变形的原因,最终确定是由于提升装置倾斜重力、硬性碰撞冲击导致提升卸载装置产生变形。通过分析,采用加强立板的方式进行改进优化,经计算验证,改进方式是可行的,可以解决阳极板载运车提升卸载装置变形的问题。     

Mechanics of translation in the fosbury-flop

The mechanics of the translations involved in the Fosbury-flop technique of high jumping were examined in the light of appropriate experimental data, generated using a 3-dimensional cinematographical method. The curved run-up was found to cause the athletes to lean toward the center of the curve at the start of the take-off phage (TD). The center of gravity (c.g.) of all the jumpers had a negative vertical velocity at TI). The lateral deviation of the path of the c.g. during the take-off phage was small, implying small centripetal forces. The initial trajectory of the parabolic path of the c.g. after the take-off made an angle of between 40 degrees and 48 degrees with the horizontal plane. During the take-off phase the take-off leg was found to flex at least as much as previouslyreported for athletes using the straddle style. One of the subjects in the study was able to clear the bar although the peak height of the parabolic path followed by his c.g. was at the same level as the bar.     

Side effects from the pulsed dye laser: the importance of skin pigmentation and skin redness

The aim of the study was to investigate the muscular load on the lower back and shoulders and the circulatory load on employees at a post center during repetitive lifting of mail transport boxes. A mock-up was designed in the laboratory, a total of nine combinations of lifting height and frequency were studied. Surface EMG was recorded bisymmetrically from m. erector spinae (L3-level) and m. trapezius. The circulatory load was evaluated by measuring the heart rate. The results show a trade off between the low back and shoulders. The maximum load on the low back occurred at the low lifting height (363 and 54.4 cm) whereas the maximum load on the shoulders occurred at the high lifting height (144.9 and 163.0 cm).     

The genome of Treponema pallidum: new light on the agent of syphilis

Covert brain activity related to task-free, spontaneous (i.e. unrequested), emotional evaluation of human face images was analysed in 27-channel averaged event-related potential (ERP) map series recorded from 18 healthy subjects while observing random sequences of face images without further instructions. After recording, subjects self-rated each face image on a scale from "liked" to "disliked". These ratings were used to dichotomize the face images into the affective evaluation categories of "liked" and "disliked" for each subject and the subjects into the affective attitudes of "philanthropists" and "misanthropists" (depending on their mean rating across images). Event-related map series were averaged for "liked" and "disliked" face images and for "philanthropists" and "misanthropists". The spatial configuration (landscape) of the electric field maps was assessed numerically by the electric gravity center, a conservative estimate of the mean location of all intracerebral, active, electric sources. Differences in electric gravity center location indicate activity of different neuronal populations. The electric gravity center locations of all event-related maps were averaged over the entire stimulus-on time (450 ms). The mean electric gravity center for disliked faces was located (significant across subjects) more to the right and somewhat more posterior than for liked faces. Similar differences were found between the mean electric gravity centers of misanthropists (more right and posterior) and philanthropists. Our neurophysiological findings are in line with neuropsychological findings, revealing visual emotional processing to depend on affective evaluation category and affective attitude, and extending the conclusions to a paradigm without directed task.     

基于AnsysWorkbench吊装工具的优化设计研究

采用有限元计算软件AnsysWorkbench对π形的吊装工具进行了强度计算,提出了计算过程中π形梁的吊装工具的模拟、六种边界条件的处理方法和优化建议。通过有限元软件进行π形梁的吊装工具的强度计算,能够为吊装作业提供数据支持,确保吊装作业的安全性。     

凝固末端电磁搅拌对77B铸坯中心偏析的影响

77B铸坯在拉拔过程中常因塑性不足而发生拉断。通过电镜、低倍等对断裂的机理进行分析,最终确定使用凝固末端电磁搅拌器来消除铸坯的中心偏析。结果表明,经过末端电磁搅拌的连铸坯试样中心偏析程度基本上得到了改善,取得了较好的效果。     

干熄焦提升机过卷保护接地装置研究及应用

针对干熄焦提升机工作保护失效,出现提升机过卷事故,导致生产中断和设备损坏的严重性,结合提升机提升和下降过程出现过卷的问题现象,对提升机提升和下降的缺陷进行分析、研究。运用提升机过卷保护接地装置,检测提升机缠绕卷筒钢绳左右水平位移距离来保护提升机安全运行。同时还介绍了该研究应用具有较好的经济价值与实用性。     

Anticipatory postural adjustments before load pickup in a bi-manual whole body lifting task

Balance regulation and movement control were examined in the context of bi-manual lifting. Subjects picked up a load (20% body mass) after several unloaded cycles using the leg-lift technique. The addition of the load to the body caused the system center of mass to shift forward and thus presented the subject with an expected perturbation of balance. To examine whether the disturbances to balance were counteracted by anticipatory postural adjustments, the last cycle, in which the barbell was grasped and lifted, was compared with the preceding unloaded cycle. Using a global mechanical analysis of the movement, we found that anticipatory postural adjustments were present before load pickup in bi-manual lifting. These anticipatory postural adjustments were characterized by a backward directed horizontal momentum, a backward directed horizontal component of the ground reaction force accompanied with a forward shift of the center of pressure, and a backward shift of the center of mass (CoM). These characteristics could all be understood from the mechanical consideration that adding a load in front of the body induces a forward shift of the CoM. However, major compensations of the position of the CoM were also observed after bar grasp. It is therefore proposed that commands giving rise to postural adjustments are closely tied to commands controlling the ongoing movement. On the basis of this insight the strict dichotomy in the control of posture and movement is being questioned.