首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
坚持党的领导、加强党的建设,是国有企业的根和魂,是国有企业的独特优势。推动国有企业改革发展,从根本上说要坚持党的领导、加强党的建设。鞍山钢铁集团有限公司党委(以下简称“鞍山钢铁党委”)坚持以习近平新时代中国特色社会主义思想为指引,积极发挥党建工作示范引领作用,通过政治引领、思想凝聚、组织建设、人才培养“四维驱动”,形成多维、立体、全面的党建工作模式,把党建优势转化为企业竞争优势、创新优势、发展优势,推动企业持续做强做优做大,实现高质量、高效率、可持续发展。  相似文献   

2.
研究了一种适用于热连轧机的新型高精度轧制力和轧制力矩模型,建立了一个轧制力功系数和轧制力矩功系数的新型指数公式,将两个系数的表达式统一起来,仅含"压下率"和"压扁半径与出口厚度之比"两个影响因子,形式简洁,物理意义明显.给出了新型指数公式中待定参数的确定方法,求得的待定参数值对不同钢种和不同精轧机架具有通用性.预测实践表明,新型轧制力和轧制力矩模型提高了热连轧过程中轧制力和轧制力矩的预报精度,可用于热轧板带生产线精轧机架的在线控制.  相似文献   

3.
非对称轧制(包括轧件跑偏、轧制力偏差等)是四辊板带轧机轴向力产生的主要原因之一.文章在弹性基础梁法的基础上,提出了研究辊系特性的变刚度弹基梁三维有限元计算模型,利用这种模型可对辊系垂向(即轧制力方向)和轧辊轴向、对称轧制(正常轧制)和非对称轧制、轧辊轴线平行及交叉诸工况进行分析.  相似文献   

4.
研究设计、制备以及表征了一种基于球形压电陶瓷壳的埋入式水泥基压电声发射传感器.相比于传统的片状压电声发射传感器只能接收特定方向信号的特点,该水泥基球形压电传感器具有全向接收信号的优势.之后,将该水泥基球形压电传感器埋入钢筋混凝土梁中,对梁试件四点弯加载过程进行了声发射监测研究.对比分析了水泥基球形压电传感器与商业外贴式片状压电声发射传感器的监测结果,包括声发射幅值、b值以及分形维数随加载过程的演化关系.结果表明,相比于商业外贴式声发射传感器,水泥基球形压电传感器可以取得较好的监测效果,且在结构加载后期对低强度信号具有更高的灵敏度.两种传感器采集到的的声发射信号的b值和分形维数均反映了结构破坏阶段的演化,可以将b值和分形维数的持续下降并维持在较低水平作为该钢筋混凝土梁试件最终破坏的预警标志.此外,相较于纯商业声发射传感器组成的定位组,该埋入式水泥基球形压电传感器所在声发射定位组捕捉到的破裂点数量大幅提高,有效提高了破裂点定位的准确度与灵敏度.  相似文献   

5.
热轧板厂采用轧制力测量系统实时测量轧制压力和空载辊缝,以间接测量和控制带钢轧制厚度。轧制力传感器本身的结构特点和其工作的恶劣环境决定了它是整个控制系统中最容易发生故障的环节之一。为了避免传感器故障造成巨大经济损失,本文针对所研发的轧制力传感器进行了传感器故障分析、诊断及隔离方法的研究,提出了一种基于卡尔曼滤波和多重假设检验的故障诊断、隔离方法,仿真证明该方法可以及时、有效地检测到传感器故障并对输出数据进行重构。  相似文献   

6.
济南钢铁集团总公司中厚板厂原粗轧机轧制压力传感器为荷兰引进的二手电阻应变支承式传感器 ,制造工艺复杂 ,体积大而重 ,安装在承受轧制力的位置上 ,直接受高压、高温及油污的恶劣环境的影响 ,损坏频繁 ,维护量大。为更有效地解决粗轧机因轧制压力过大而经常造成断轴事件的问题 ,我们采用了并联方式安装在轧机侧面附着式压力传感器。附着式压力传感器是根据轧制力分流测量原理和灵敏度机械放大原理构成的 ,具有“以小测大”功能的超轻型电阻应变式传感器。通过直接测量由轧制力引起的轧机牌坊立柱的拉伸应变和电阻应变效应来间接测量轧制力…  相似文献   

7.
根据Sims公式和由滑移线场理论导出的公式计算板坯轧制力,并采用二维刚塑性有限元法计算了板坯轧制力,所得结果与文献介绍的实验数据相比,其精度较好.  相似文献   

8.
四辊轧机冷轧带材各力参数的实验研究   总被引:3,自引:0,他引:3  
刘宏民  段振勇 《钢铁》1992,27(6):31-35,41
在轧件宽厚比从15到625的较大范围内,对轧制铝带时的压力、两向摩擦力和前后张力的横向分布进行了比较全面的研究,考察了弯辊力、前后总张力变化的作用效果,给出了不同板形状态下的各力参数横向分布规律,对实际生产有指导意义。  相似文献   

9.
新型聚合物石英压电传感器制备过程中,AT切型石英压电传感器基体的表面粗糙度及其基膜界面化学性质影响聚合物薄膜的生长,导致聚合物薄膜厚度不均匀、表面存在缺陷,使得传感器采集的频率信号不稳定.本文建立了新型聚合物石英压电传感器在考虑薄膜厚度不均、中心缺陷条件下的力学模型,利用ANSYS有限元软件对其进行模态分析,得到复杂条件下传感器振动特性.模态分析结果发现,传感器固有频率值随聚合物薄膜缺陷的半径值增大呈现出从稳定到发散的趋势、随薄膜的厚度值增大呈现出线性增大的趋势.研究结果表明,新型聚合物石英压电传感器的生产应确保薄膜厚度均匀且严格控制中心缺陷半径小于0.5 mm,该结果为制备稳定的新型聚合物石英压电传感器提供了重要依据.  相似文献   

10.
本文利用影响函数分析方法对辊系的轴向特性进行了分析,除讨论了辊系不对称变形而引起的轴向力外,还讨论了在交叉情况下,辊系受力不均匀及由此造成的变形不对称对轴向力计算理论的影响.  相似文献   

11.
A battery-portable respirable aerosol sensor has been experimentally evaluated. Calibration procedures are described. For instruments calibrated with welding smoke, test results show agreement within +/- 15% of parallel filter samples for 10 laboratory and industrial aerosols including welding and tobacco smoke, oil mist, cotton and asbestos mill dusts, powdered metal and walnut shell dusts, and atmospheric urban aerosol in the 0.05-5.5 mg/m3 range. Results show that an average of several piezobalance measurements can accurately simulate a time-integrated filter sample in many industrial environments.  相似文献   

12.
 51CrV4钢因具有良好的热处理性能与力学性能,广泛用作为高等级弹簧钢。为改善现有锯片钢的不足,根据51CrV4特有的化学成分,创新性地将其用于制造金刚石焊接锯片基体。通过研究动态CCT曲线,卷取温度对显微组织与第二相析出物的影响,淬火与回火工艺对碳化物尺寸、晶粒尺寸、力学性能的影响,评估了51CrV4钢用于制造金刚石焊接锯片基体的可行性。结果表明:卷取温度升高,先共析铁素体尺寸与珠光体片层间距变大,10 nm粒径以下的(V,Cr)C析出物在MC相析出物中所占的比例减少;淬火温度由800提高到900 ℃时,奥氏体晶粒尺寸先缓慢变化,随后快速长大,固溶的碳化物质量分数增多,回火后锯片硬度增强,而回火温度由450提高到550 ℃时,马氏体板条界片层状渗碳体逐步球化,强度明显下降,塑性小幅提高;设定合适的卷取温度控制热轧态中第二相碳化物的尺寸,并在850~900 ℃淬火、约450 ℃回火是生产高硬度、高韧性51CrV4金刚石焊接锯片的关键工艺。  相似文献   

13.
When we manipulate objects in everyday tasks, there are variations in the shape of the grasped surfaces, and the loads that potentially destabilize the grasp include time-varying linear forces and torques tangential to the grasped surfaces. Previous studies of the control of fingertip forces for grasp stability have dealt principally with flat grip surfaces and linear force loads. Here, we studied the regulation of grip force with changes in curvature of grasped surfaces and changes in tangential torque applied by the index finger and thumb when humans lifted an object and rotated it about the horizontal grip axis through an angle of 65 degrees. The curvatures of the matched pair of spherical surfaces varied from -50 m-1 (concave with radius 20 mm) to 200 m-1 (convex with radius 5 mm). The applied tangential torque at the orientation of 65 degrees was varied sixfold. Regardless of the values of curvature and end torque, grip force and tangential torque were coordinated, increasing in parallel throughout the tilt with an approximately linear relationship; the slope of the line increased progressively with increasing surface curvature. This parametric scaling of grip force was directly related to the minimum grip force required to prevent rotational slip, resulting in an adequate safety margin against slip in all cases. We conclude that surface curvature parametrically influences grip force regulation when the digits are exposed to torsional loads. Furthermore, the sensorimotor programs that control the grip force apparently predict the effect of the total load comprising linear forces and tangential torques.  相似文献   

14.
总结了Cu/Mo/Cu平面层状复合材料的特点和应用,通过平面层状结构设计,可以实现其在平面(x,y)方向更低的热膨胀系数和更高的热导率,其中热导率最高可达370W·m-1·K-1;介绍了其研究现状和制备方法,并通过对制备工艺的对比分析,指出热压复合和轧制复合是Cu/Mo/Cu层状复合材料生产工艺的发展趋势及方向.  相似文献   

15.
Sometimes main driver motors' torque exceeds the maximum limit in Baosteel's 5 m heavy plate mill. Experience showed that torque overloaded occurred in cases of some special rolling sequence and special rolling plate dimension.Most of the overloaded occurred only instantaneous at some time point during the rolling pass, which especially easily happened at the bite and motor acceleration time after the bite.This paper analyzes the impact factors for motor torque overload and carefully studies the key deta...  相似文献   

16.
We examined the idea that aspartate metabolism by Lactobacillus subsp. M3 is organized as a proton-motive metabolic cycle by using reconstitution to monitor the activity of the carrier, termed AspT, expected to carry out the electrogenic exchange of precursor (aspartate) and product (alanine). Membranes of Lactobacillus subsp. M3 were extracted with 1.25% octyl glucoside in the presence of 0. 4% Escherichia coli phospholipid and 20% glycerol. The extracts were then used to prepare proteoliposomes loaded with either aspartate or alanine. Aspartate-loaded proteoliposomes accumulated external [3H]aspartate by exchange with internal substrate; this homologous self-exchange (Kt = 0.4 mm) was insensitive to potassium or proton ionophores and was unaffected by the presence or absence of Na+, K+, or Mg2+. Alanine-loaded proteoliposomes also took up [3H]aspartate in a heterologous antiport reaction that was stimulated or inhibited by an inside-positive or inside-negative membrane potential, respectively. Several lines of evidence suggest that these homologous and heterologous exchange reactions were catalyzed by the same functional unit. Thus, [3H]aspartate taken up by AspT during self-exchange was released by a delayed addition of alanine. In addition, the spontaneous loss of AspT activity that occurs when a detergent extract is held at 37 degrees C prior to reconstitution was prevented by the presence of either aspartate (KD(aspartate) = 0.3 mm) or alanine (KD(alanine) > or = 10 mm), indicating that both substrates interact directly with AspT. These findings are consistent with operation of a proton-motive metabolic cycle during aspartate metabolism by Lactobacillus subsp. M3.  相似文献   

17.
18.
Comments on establishing the concept of development as a dynamic force in the field of health psychology. It is contended that one potential direction is an increased emphasis on life-span interventions and on the identification of critical developmental junctures of vulnerability to health risks and receptivity toward health interventions. The most effective way to map those areas of development in which highest risk or greatest receptivity in intervention occurs is to examine the process of development by using a longitudinal design with age-appropriate, periodic measurement of all relevant variables. For the most part, psychologists' interests should be on the area in the developmental continuum that characterizes study participants' abilities and experiences, instead of participants' chronological age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

19.
C/C复合材料是一种良好的抗烧蚀和耐高温结构材料,广泛地应用于航天航空各领域。在此,作者综述了C/C复合材料烧蚀性能的测试方法、烧蚀机理、烧蚀模型以及抗烧蚀的研究状况。  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号