基于有限元法的气动钉枪手柄的振动分析

气动钉枪的手柄振动对操作者身体健康有重要影响。运用Pro／E软件建立气动钉枪整枪装配模型。采用有限元法建立气动钉枪手柄振动分析的力学模型。借助ANSYSWorkbench软件对整枪进行工作状态的振动分析。得到操作者抓握位置的振动加速度分布,并通过不同减振方案对比分析,获得手柄皮套参数优化设计理论依据。     

Overall quality of ‘Rich Lady’ peach fruit after air- or CA storage. The importance of volatile emission

In this work, ‘Rich Lady’ peach fruit picked at three different dates were stored at 2 °C under air or controlled atmosphere (CA) conditions for 3 or 15 days with the purpose of assessing the effects of the different factors considered on some variables (standard quality parameters and emission of volatile compounds) potentially having an impact on sensory acceptance after storage. Extending cold storage under air resulted in lowered acceptance scores, which were improved by CA storage. Multivariate analysis of results revealed that acceptance of ‘Rich Lady’ peach fruit was related closely to the perception of the characteristic flavour, which in turn was related to soluble solids content and to the emission of specific volatile compounds. Observed differences in alcohol o-acyltransferase (AAT) activity as affected by factors considered in this work did not appear to be large enough to explain differences in ester production after storage. Data suggest that observed differences in the emission of volatile esters arose mainly from modifications in the activity of enzymes located upstream of AAT, causing changes in the supply of precursors for ester biosynthesis in ‘Rich Lady’ peach fruit.     

中原油田高含水轻质油藏注空气提高采收率技术探讨

介绍了注空气提高采收率技术的原理及其在国内外的实验研究和现场应用情况,针对中原油田的地层条件,分析探讨了实施注空气技术的可行性和广阔的应用前景,建议在高含水轻质油藏率先进行现场试验,将会在技术上有所突破,并带来可观的经济效益。     

Effect of environment humidity and temperature on stationary and transient flying responses of air bearing slider

It is well known that the environment humidity and temperature have a significant influence on the flying height of an air bearing slider. However, not many research papers address this topic, especially when the transient flying response is considered. This paper studies the influences of the environment humidity and temperature on both the stationary and transient flying responses of slider by simulation. A slider design for the thermal protrusion application is addressed. The reason for causing the drop of the air bearing pressure is discussed, and the methods for decreasing the drop are proposed. It is observed that the environment humidity and temperature may determine whether the slider is in full flying state or in partial flying/partial dragging state, when the slider is released from a certain height. The reason may be due to the high humidity and temperature which weakens the air bearing. As a result, the air bearing becomes not strong enough to support well the full flying of slider when the influence of the intermolecular force is significant. Slider vibrations for the full flying case and the partial flying/partial dragging case are analyzed in frequency domain, and the slider vibration frequencies are discussed. It shows that the environment temperature and humidity have significant effects on both the stationary and transient flying responses of the slider.     

yankee烘缸与高温热风气罩结合用于纸幅干燥节约能量、提高质量和增加产量

该文论述新颖热风气罩与传统yankee烘缸,联合使用于生活用纸纸幅干燥取得很好效果,在提高热风温度25%～30%的情况下使过程的干燥速率加快30%～50%。运种新颖热风气罩是在老式平台的基础上对其结构设计和材料强度进行优化和改进而成,从而能突破传统干燥过程里空气受到温度限制,从而在作业过程里实现节约能量、提高质量和增加产量。     

新型纺织空调喷淋室的设计与应用

探讨新型纺织空调喷淋室的设计及应用效果.通过分析目前常用喷淋室的结构及缺陷,设计了新型纺织空调喷淋室.新型纺织空调喷淋室由两排至五排喷淋排管构成,并按照一定方式组合使用.通过喷淋室高密度水雾横喷、逆喷等方法,可以提高空气与水热湿交换效率及空气质量.以五排喷淋排管喷淋室为例对比说明:五排喷淋排管喷淋室能够实现冷却、加湿等多种功能,同时高效环保,是一种理想的纺织空调喷淋室.     

纺织厂空调下送风系统应用探讨

探讨纺织厂空调下送风系统的设计与应用效果.通过分析空调下送风技术的原理与发展现状,在2万锭前纺车间及细纱车间分别进行了下送风设计与运行试验.认为:纺织厂下送风系统与多点喷雾无喷嘴节能中央空调机组相结合在节能降耗方面表现出较大优势.正确选择出风12'位置和形状尺寸以及出口风速、风向是设计下送风的关键.     

[ecosistema urbano]

Polish architecture tutors and critics Roman Rutkowski and Lukasz Wojciechowski identify a new kind of architecture in [ecosistema urbano]'s ingenious temporary tower pavilions for a sterile new housing estate in Madrid. Contributing power to the local electricity grid, these towers are explicitly designed to provide shelter from the unmediated heat of the harsh external environment through their cooling effect and in so doing to stimulate communal activities and events. Copyright © 2009 John Wiley & Sons, Ltd.     

双单元建筑物的换气速度和内部流动的测量

采用示踪气体稀释法对选定的双单元建筑物的换气速度和内部流动进行了测量,以期建立一种实际测量的方法,同时获得一些有用的数据。测量结果表明,选定的建筑物具有令人满意的换气速度,内部流通良好,可满足室内空气质量的要求,但对污染事故的屏蔽能力较差。本工作可以为研究室内空气质量和建筑物屏蔽因子提供一些借鉴。     

新建风井留设小保护煤柱与抗变形技术的研究

以平煤集团公司四矿新建千米进风井为例,系统研究了新建风井留设小保护煤柱的可能性,提出了井筒抗变形技术措施,为深部矿井风井建设提供了可资借鉴的技术途径。