蠕变时效成形工装设计研究

蠕变时效成形技术在航空航天器件中大型复杂整体壁板类零件的制造上具有独特优势,被认为是大型飞机重要的金属成形工艺之一。介绍了蠕变时效成形工装的技术要求,针对蠕变时效成形时的特点,结合成形工装的设计要求,设计制造了基于机械加载式成形工装和基于气压加载且自备加热系统的成形工装,两种工装既简单又实用,特别是后者具有较强的工程应用价值。经蠕变时效成形后的零件材料力学性能有所提高。     

挤出机双流道筒体的设计及换热能力的计算与分析

介绍了设计双流道筒体的必要性,通过建立物理、数学模型详细论述了双流道筒体的设计原理及换热计算过程,并通过试验对比分析验证了模型的可靠性,同时对单、双流道筒体的换热能力进行对比分析,得出了可靠的结论.     

短纤维链板式松弛热定型机流场的研究

分析了链板式松弛热定型机的结构及运行特点;通过对链板式松弛热定型机的冷态测试实验,获得了热定型机内部流场气流的速度分布数据,以探讨热定型机内部流场的特点。结果表明:在纤维层上部存在着明显的气流不均匀现象,匀风板上部具有高速气流区;指出热定型风板开孔不合理,导致纤维层上部气流分布不均匀,气流短路使得散热器下部流场分布不均匀;提出改善热定型机匀风板的开孔率,可实现均匀布风的初步方案。     

山水交融,生态校园——湖南潇湘技师学院新校区方案设计

该文通过对湖南潇湘技师学院新校区规划设计方案的分析介绍,阐述了校园建筑应以人为本,与生态环境相融合。同时为现代新校园的设计提出创造性的理念。     

托辊轴承系列产品塑料保持架的改进

托辊轴承应用于煤矿带式输送机和农业带式输送机中,其轴承工作环境恶劣,灰尘大,在煤泥水和其他有害的气体环境中运转。因此,托辊轴承对旋转阻力、防卡寿命具有一定的要求。为满足托辊轴承性能要求,首先在保持架的材料选取及保持架结构设计上进行了改进。保持架的材质采用了性能优良的工程塑料,并在保持架的结构上进行了改进-增加了叶片。因此,提高了轴承的寿命及动态性能。     

PLC过程控制故障分析与排除

在分析PLC过程控制的故障特点的基础上,通过实例,介绍了4种故障分析与排除的方法。     

基于MCS-51的工频弱磁测量仪的研制

介绍了一种基于MCS-51的工频弱磁测量仪,能测量1mGs到1000mGs(即10-7T～10-4T)范围内、方向未知的工频磁场,可以作为环境工频磁场的有效监测手段。     

电线电缆抽样检测问题分析

对一年来开展的电线电缆抽样检测工作情况进行全面分析,介绍了影响电线电缆质量的主要指标,如导体直流电阻、绝缘厚度、绝缘热延伸等,认为产生质量问题的主要原因是产品生产企业技术、设备落后、管理水平较低及市场无序竞争等。对此提出完善电网设备材料的全生命周期质量管理、不断提高电线电缆抽样检测手段、加强对电线电缆生产行业的质量监管等提高电线电缆质量的措施,为加强入网设备材料管理及电线电缆抽样检测工作提供技术参考。     

Finite element computations of specific absorption rates inanatomically conforming full-body models for hyperthermia treatmentanalysis

The formulations used center on Helmholtz weak forms which have been shown to be numerically robust and to afford additional sparsity in the resulting system of algebraic equations. Practical solution of these equations depends critically on the realization of an effective sparse matrix solver. Experience with several conjugate gradient-type methods is reported. The findings show that convergence rate (and even convergence in some cases) degrades significantly with increasing matrix rank and decreasing electrical loss for mesh spacings which adequately resolve the physical wavelengths of the electromagnetic wave propagation. However, with proper choice of algorithm and preconditioning, reliable convergence has been achieved for matrix ranks exceeding 2×10 5 on domains having sizeable volumes of electrically lossless regions. An automatic grid generation scheme for constructing meshes which consist of variable element sizes that conform to a predefined set of boundaries is discussed     

Using fluorinated and crosslinkable fullerene derivatives to improve the stability of perovskite solar cells

Organic-inorganic hybrid perovskite solar cell (PSC) is a third-generation photovoltaic technology[1,2],and the certi-fied power conversion efficiency (PCE) has reached 25.5％(https://www.nrel.gov/pv/cell-efficiency.html),which can rival solar cells based on crystalline-Si and other inorganic semi-conductors.The intrinsic instability of perovskite materials could impede PSC commercialization[3].To date,a variety of strategies such as composition engineering,additive engi-neering,interface engineering and encapsulation technique are employed to improve the long-term stability of PSCs[4-9].In particular,fullerene materials with high electron mobility,high electron affinity,small reorganization energy and ad-justable energy level have been widely utilized as interfacial layers or additives in PSCs for efficiency and stability improve-ment[10].Among them,fluorinated and crosslinkable fullerene derivatives can improve the stability of PSCs effectively.The fluorinated fullerene derivatives could improve the mois-ture stability because of the hydrophobicity of fluorine atom.The crosslinked fullerene derivatives can protect the electron-transport layers (ETLs) against solvent erosion during per-ovskite solution deposition,and the as-formed organic net-works can improve mechanical stability of PSCs.