大型深沟球轴承径向游隙的测量

大型深沟球轴承外形尺寸大、质量重,其径向游隙在现有仪器上无法得到准确的测量。根据该类轴承的特点与国家标准,对现有测量仪器进行了改进,设计了加载装置,使轴承按照规定的加载量进行加载,保证了径向游隙的准确测值。此种测试方法使用方便、测量效率高。     

含多间隙副特高压断路器传动机构动力学特性研究

为研究间隙对特高压断路器传动机构动力学特性的影响,利用非线性弹簧-阻尼模型模拟了接触碰撞中的法向力,利用修正的库仑摩擦力模型模拟了接触碰撞中的切向力,建立了该机构含多间隙副的多体动力学模型。运用多体系统动力学软件ADAMS,在特定工况下对传动机构的合闸过程进行了动力学仿真分析。仿真结果表明,运动副间隙对传动机构位移影响较小,但对速度和加速度影响较大,且随着间隙增大,这种影响越显著,机构的运动稳定性越差。     

不锈钢水泵底架成形工艺及模具设计

分析了水泵底架原冲压成形工艺存在的问题,提出了新的成形工艺方案,介绍了新工艺中关键工序的模具结构以及模具加工、现场调试应注意的事项。经生产验证,改进后的工艺与模具结构合理,产品质量及生产效率大大提高。     

高速压力机滑块液压过载保护结构设计与分析

介绍了高速压力机的一种滑块液压过载保护装置，并结合本厂高速压力机产品的开发实例，对装置结构进行了分析。     

Association of IgG1 Antibody Clearance with FcγRIIA Polymorphism and Platelet Count in Infliximab-Treated Patients

The FcγRIIA/CD32A is mainly expressed on platelets, myeloid and several endothelial cells. Its affinity is considered insufficient for allowing significant binding of monomeric IgG, while its H131R polymorphism (histidine > arginine at position 131) influences affinity for multimeric IgG2. Platelet FcγRIIA has been reported to contribute to IgG-containing immune-complexe clearance. Given our finding that platelet FcγRIIA actually binds monomeric IgG, we investigated the role of platelets and FcγRIIA in IgG antibody elimination. We used pharmacokinetics analysis of infliximab (IgG1) in individuals with controlled Crohn’s disease. The influence of platelet count and FcγRIIA polymorphism was quantified by multivariate linear modelling. The infliximab half-life increased with R allele number (13.2, 14.4 and 15.6 days for HH, HR and RR patients, respectively). It decreased with increasing platelet count in R carriers: from ≈20 days (RR) and ≈17 days (HR) at 150 × 10⁹/L, respectively, to ≈13 days (both HR and RR) at 350 × 10⁹/L. Moreover, a flow cytometry assay showed that infliximab and monomeric IgG1 bound efficiently to platelet FcγRIIA H and R allotypes, whereas panitumumab and IgG2 bound poorly to the latter. We propose that infliximab (and presumably any IgG1 antibody) elimination is partly due to an unappreciated mechanism dependent on binding to platelet FcγRIIA, which is probably tuned by its affinity for IgG2.     

单卷简双驱动形式齿轮副侧隙值对同步运行的影响

在调整单卷筒双驱动形式的同步时,齿轮副侧隙调整值与单卷筒单驱动的形式不同,齿轮副侧隙调整值适当放大才能保证大小齿轮的正确啮合,再加上电气补偿,就能实现双驱动形式的同步和双吊点的同步。     

Experimental Study onAqueous Phase Entrainment in a Mixer-settler with Double Stirring Mode

The mixer-settler is a core device of solvent extraction for separating rare earth elements. There are some adverse effects like high rare earth accumulation and poor production efficiency during industrial production. Current researches usually focus on changing the structure of the mixer-settler without making a breakthrough towards gravity clarification. In this paper, in order to improve the efficiency of clarification, a mixer-settler with double stirring mode was designed and manufactured by adding a stirring device in the settler after reducing the volume of the settler. The innovation of this research involves adopting the ultraviolet-visible spectrophotometer to investigate the quantity of aqueous phase entrainment at the settler outlet in order to measure the clarification degree. Experimental results show that the clarification effect with stirring is better than that without stirring. The clarification effect is ameliorated as the stirring speed increases. Generally, the clarification effect shows a best condition when the offset distance is 12.5 cm, making the phase entrainment reduced to less than 0.1%. When the clearance over the tank bottom is 7 cm and 10 cm, respectively, the quantity of aqueous phase entrainment is better than the case with a clearance of 4 cm. The results show that the stirring paddle close to the mixed phase zone can better promote the two-phase separation.     

有限厚度带键槽接缝单元及接缝对混凝土坝应力的影响

本文给出了有限厚度的带键槽三维实体接缝单元，它可以较好地反映接缝附近的应力和接触条件。文中分析了接缝的初始间隙问题，分析结果表明，经过灌浆以后，由于浆体收缩而产生的初始间隙是很小的，一般可以忽略。文中还分析了灌浆质量对坝体应力的影响，分析结果表明，只要浆体灌进了接缝，虽然浆体质量差一些，带有键槽的接缝对坝体应力和变形的影响是很小的。本文最后分析了横缝不抗拉对拱坝应力的影响，分析结果表明，这个问题与横缝受拉深度a和横缝间距L的比值a/L有关，a/L越大，横缝不抗拉对坝体应力的影响越大，此外，还与坝体厚度及气候条件有关。     

基于响应曲面模型的泵站进水池参数优化方法研究

泵站进水池的结构参数,特别是吸水喇叭管参数取值对泵站整体流态影响很大。本文基于响应曲面模型和CFD数值模拟,以垂直布置的吸水喇叭管悬空高、后壁距和淹没深度为设计变量,以进水池压力场、速度场和涡量场评价指标的加权函数为目标函数,进行2因素和3因素的优化设计分析。研究结果表明,变量之间对进水池流态的交互作用较大,淹没深度对最优悬空高、后壁距的影响不可忽略,且淹没深度与悬空高的交互作用(P=0.0019)较其与后壁距的交互作用(P=0.0696)大。针对本文垂直布置型式的吸水喇叭管,推荐最优参数组合是悬空高0.77 D,后壁距0.37 D,淹没深度2.19 D。在该组合下实际值与预测值误差不大于4.82%,与泵站设计规范推荐值相比,其计算域水力损失降低0.98%,流速分布均匀度提高5.92%,机组纵剖面涡量分布特征值降低3.1倍,大大改善了进水池的流态。这表明所建立的二次多项式响应面模型能够较精确地表示设计变量与目标函数之间的关系,基于响应曲面模型的优化设计方法可有效用于泵站进水流场的流态优化。     

柱塞气举过程液体漏失分析

在柱塞上行程过程中,由于柱塞和油管之间的液体与柱塞之间存在速度差,必然会有液体漏失。液体漏失率的大小影响着柱塞尺寸的选择以及柱塞气举工艺的设计,因此液体漏失率的计算具有重要的意义。假设柱塞上行过程中与油管始终保持同心圆柱环形间隙运动,基于质量和动量守恒原理建立了柱塞气举的液体漏失模型,并得出了柱塞-油管环形间隙的液体速度分布公式和液体漏失体积及漏失率表达式。引用Hernandez等的柱塞气举试验数据,进行液体漏失情况的计算,得出了液体漏失与柱塞上部液体段塞初始长度和注气压力的关系曲线。文中建立的模型对于正确地进行柱塞气举工艺设计具有一定的指导意义和实用价值。