螺旋锥齿轮数控磨齿机机床空间误差与机床调整参数的关系

为求得对各项机床调整参数影响较大的机床空间误差,分析螺旋锥齿轮加工过程中数控机床空间误差物理涵义,并建立七轴五联动数控磨齿机床空间误差模型.基于齐次变换矩阵方法建立机床空间误差与机床调整参数之间的几何等量关系,推导出两者间的关联函数并进行分析.通过实例分析,发现对机床刀位调整值影响较大的机床空间误差主要是三直线轴垂直度误差和x轴沿Z向垂直度误差;对机床轮位调整值影响较明显的机床空间误差为z轴、B轴沿x向直线度误差以及A轴的安装距误差.为机床调整参数优化及螺旋锥齿轮几何误差补偿提供了理论依据.     

印度某赤铁矿洗矿溢流选矿试验

为了给铁品位在50%左右的印度某赤铁矿洗矿溢流的利用提供依据,采用细筛-强磁选-阴离子反浮选流程和细筛-螺旋溜槽-强磁选-阴离子反浮选流程对该洗矿溢流进行了选矿试验。试验结果表明,在-0.076 mm占75%的磨矿细度下,两流程分别可取得精矿铁品位为67.01%,回收率为87.77%和精矿铁品位为67.12%,回收率为89.71%的选别指标。鉴于后一流程可比前一流程减少约1/3的浮选量,因此推荐采用后一流程。     

V型缠绕垫片的力学分析及性能研究

对V型缠绕式垫片进行简化力学分析，并通过合理的设计、性能试验加以验证。     

电机—机械传动式电动螺旋压力机传动齿轮设计技术经济浅析

利用齿轮接触应力、弯曲应力和滚齿费用表达式,推导出设计传动齿轮尺寸的综合技术经济关系式,分析关系武中各个变量对零件结构尺寸和制造费用的影响.     

蜗壳拉深模的稀土离子氮化

试验表明,稀土对离子氮化有明显的催渗作用。离子氮化能提高模具的硬度,降低摩擦系数,不再出现粘着磨损,显著提高拉深模的寿命。     

Spiral column configuration for protein separation by high-speed countercurrent chromatography

Retention of the stationary phase of aqueous–aqueous polymer phase systems is improved by a spiral column configuration which utilizes the radially acting centrifugal force along the spiral pitch to retain the heavier phase in the outer portion and the lighter phase in the inner portion of the spiral channel. For the separation of proteins which has low mass transfer rates, the system needs further modification of the separation channel to interrupt the laminar flow and enhance mixing of the two phases.     

八字形螺旋槽端面密封及其系统在2MCL—457离心压缩机上的试应用

介绍了八字形螺旋槽端面密封及其系统在２ＭＣＬ－４５７型离心式富气压缩机上的应用情况该密封及其系统具有较大的推广价值。     

复合控制算法在榴弹螺旋装药中的应用

榴弹螺旋装药的压药压力控制系统中,采用开环补偿控制和闭环控制结合的复合控制.开环补偿控制根据扰动量直接产生相应的补偿,以抵消其影响.而闭环反馈控制则用于克服各种干扰和对控制效果最终检验.其PID控制采用位置算法,并对控制量输出和积分增量限幅.该算法在具体的项目中得到成功的应用.     

Impact of Scaffold Micro and Macro Architecture on Schwann Cell Proliferation under Dynamic Conditions in a Rotating Wall Vessel Bioreactor

Over the last decade tissue engineering has emerged as a powerful alternative to regenerate lost tissues owing to trauma or tumor. Evidence shows that Schwann cell containing scaffolds have improved performance in vivo as compared to scaffolds that depend on cellularization post implantation. However, owing to limited supply of cells from the patients themselves, several approaches have been taken to enhance cell proliferation rates to produce complete and uniform cellularization of scaffolds. The most common approach is the application of a bioreactor to enhance cell proliferation rate and therefore reduce the time needed to obtain sufficiently significant number of glial cells, prior to implantation.In this study, we show the application of a rotating wall bioreactor system for studying Schwann cell proliferation on nanofibrous spiral shaped scaffolds, prepared by solvent casting and salt leaching techniques. The scaffolds were fabricated from polycaprolactone (PCL), which has ideal mechanical properties and upon degradation does not produce acidic byproducts. The spiral scaffolds were coated with aligned or random nanofibers, produced by electrospinning, to provide a substrate that mimics the native extracellular matrix and the essential contact guidance cues.At the 4 day time point, an enhanced rate of cell proliferation was observed on the open structured nanofibrous spiral scaffolds in a rotating wall bioreactor, as compared to static culture conditions. However, the cell proliferation rate on the other contemporary scaffolds architectures such as the tubular and cylindrical scaffolds show reduced cell proliferation in the bioreactor as compared to static conditions, at the same time point. Moreover, the rotating wall bioreactor does not alter the orientation or the phenotype of the Schwann cells on the aligned nanofiber containing scaffolds, wherein, the cells remain aligned along the length of the scaffolds. Therefore, these open structured spiral scaffolds pre-cultured with Schwann cells, in bioreactors could potentially shorten the time needed for grafts for peripheral nerve regeneration.     

挤砖机生产能力的分析与探讨

本文对挤砖机的生产能力在理论上进行了分析探讨,确定了挤砖机生产能力的理论计算方法,并对其影响生产能力的主要参数进行了分析讨论,为今后挤砖机设计中合理确定主要参数提供了理论依据.