碳纤维/环氧复合材料制备工艺对自润滑性能的影响

本文探讨了采用碳纤维/环氧树脂复合材料制造自润滑轴承的基本工艺。对不同固化剂对材料的自润滑性能进行了试验分析,并对比其结果。使用电子显微镜及光学显微镜对断口及摩擦表面进行了观察。     

煤矿坑口电厂冷凝器旋转纽带连续清洗节能技术

介绍了作者对水垢—汽轮机冷凝器真空度影响状况的调查及其水垢引起的经济损失 ,叙述了自转塑料纽带的连续清洗和传热强化原理 ,试验表明自转塑料纽带的连续清洗能力能够满足冷凝器污垢清洗的要求 ,并且兼有幅度为 9%～ 15 %的传热强化作用 ,长时间的考核试验运行没有发现纽带对铜管壁的磨损问题 ,计算分析说明连续清洗纽带对提高机组真空度的增产增效的作用显著     

Novel starch based copolymers (DiHydroxyl Starch) as ocular lubricants: Synthesis and characterizations

Dry eye syndrome is an ocular tear deficiency disorder that affects millions of people in the United States. It has been recognized as a significant lifestyle issue and is among the most frequently established diagnoses in ophthalmology. Tear substitutes (or artificial tear formulations) are the mainstay of dry eye therapy. While many commercial products are available, their efficacy is limited because of their short retention time in the eye, and/or low patient acceptance. In this study, our objectives were to obtain water soluble products with opened glucose rings along the starch backbone, and tear substitute formulations based on these products with strengthened mucoadhesion, shear thinning behavior, improved tear film stability, and no irritancy to the eye. To this end we have synthesized a series of starch based copolymers, DiHydroxyl Starches (DHS). This modification of starch is not a new science, but the application of these polymers to tear substitutes is novel. These polymers were characterized as ocular lubricants utilizing both in vitro and in vivo testing. Specifically, mucoadhesion and rheological behavior were examined. Their performance as ocular lubricants was evaluated utilizing the tear‐film break up times of rabbits before and after application of the copolymers. In addition, the effect of autoclaving and ocular toxicity were tested. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

机床夹具元件的磨损及对策分析

本文对机床夹具元件的磨损情况进行了分析,特别对减少机床夹具元件的磨损、提高其使用寿命的措施进行了探讨,其具体措施有：合理调整夹具相关尺寸;有效润滑;合理设计夹具结构和提高夹具易损件的表面硬度     

沸腾锅炉受热面金属管磨损机理分析与预防

分析了沸腾锅炉埋管,过热器,省煤器等受热面金属管磨损减薄的原因,采取相应的防腐措施。     

Failing the Informal City: How Rio de Janeiro's Mega Sporting Events Derailed the Legacy of Favela-Bairro

The eviction of thousands of inhabitants from informal settlements has been a regressive feature in the lead up to Rio 2016. Writer and curator Justin McGuirk describes why, on the eve of the Olympic Games, the government reverted to favela removals after the enlightened era of the Favela-Bairro in the 1990s, which saw informal communities upgraded and integrated into the formal city.     

流化床锅炉燃用烟煤风帽磨损的问题分析

介绍了循环流化床锅炉改烧烟煤的时候布风板风帽的一些问题以及相关的分析,介绍了运行调整的方法和解决措施。     

铸钢件摇臂裂纹原因分析及改进

在对内燃机气门摇臂进行磁粉探伤时发现有裂纹存在。通过化学成分分析及金相检验分析了裂纹产生的原因。结果表明:该裂纹为铸造过程的热裂纹;通过加大模具过渡区的圆角及减小内浇口尺寸,可消除铸件热裂纹的产生。     

热辐射对消防服热防护性能及耐久性的影响

为探讨低热辐射对消防服用织物热防护性能及物理机械性能的影响,选用两种常用消防服用外层织物,利用远红外石英灯管辐射仪,以不同的辐射强度(6.5kw/m2和9.7kw/m2)对织物分别进行5、10、20、30min的辐射,利用NI虚拟仪器记录辐射时织物表面温度,并测试其各项物理机械性能及TPP值变化。结果表明:当织物表面温度低于织物纤维玻璃化温度时,织物在半小时内能保持其68.9%～84.6%的撕破强力,且TPP值增大,即热防护性能变好;而当织物表面温度达到纤维玻璃化温度时,织物断裂强力及撕破强力随辐射时间增加显著下降,但其TPP值仍增大。     

奥氏体高锰钢的切削过程与形变强化规律

金属切削过程是切削层金属的塑性变形和断裂过程 .切削过程中 ,金属的形变强化、裂纹形成与长大的知识对理解切屑分离和流出是必要的 .本文应用快速落刀及金相分析方法研究了奥氏体温锰钢 5 0Mn18Cr4切削变形过程中的形变强化和微裂纹形成与扩展规律 .研究表明 ,切削过程中的形变强化规律符合幂函数规律 ;切削刃处切削材料的分离是该局部材料形变强化达到断裂应力的结果 ;奥氏体高锰钢切屑属挤裂型切屑 ;切屑断裂源于剪切带 ;在切屑沿前刀面流出过程中 ,因流速不等而产生的弯矩是导致切屑局部剪切失稳的重要原因