Experimental study on absorption of blade vibration of honeycomb seal and shunt injection

Honeycomb seals and shunt injection have been proposed to weaken the blade vibration. Honeycomb seals, as well as, smooth seals were tested with different seals' clearances and shrouded blades. The shunt injection was sprayed to the blade tip clearance in the reverse direction of the main flow. Experimental results showed that both honeycomb seals and shunt injection had the damping effect for blade vibration, and the blade vibration magnitude could be reduced by more than 25% and 17%, respectively. When the two methods were adopted synchronously, more than 1/3 of the blade vibration could be reduced. Consequently, adopting honeycomb seal and superinducing proper shunt injection are two useful ways to minimize vibration of the blade from the viewpoints of avoiding blade rupture and improving the rotor stability.     

车用旋转密封件动压槽型线优化研究

分析了三次样条插值函数作为车用旋转密封件不同槽型曲线通用描述函数的可行性,研究了槽型曲线通用函数参数的确定方法,并利用贴体坐标变化,将物理域中任意不规则槽型转换为计算域中规则的扇形槽型,实现了对不规则槽型润滑模型的统一求解.在此基础上,以最大油膜承载力为目标,建立了旋转密封件的槽型优化模型,并采用试验设计法完成了多变量优化问题的求解;最后,比较分析了优化槽型、螺旋槽和直线槽的油膜承载力和压力分布特性.研究表明:三次样条插值函数可作为旋转密封件动压槽型的通用描述函数;型线中部具有凸峰的优化槽型,比螺旋槽和直线槽具有更大的油膜承载力.      

生产测井井下仪器密封的设计

密封是井下仪器不可忽视的组成部分，其可取程度与仪器的工作情况密切相关。密封失效对于井下仪器来说是致命的危险，可导致仪器报废。     

Friction Characteristics of Mechanical Seals with Laser-textured Seal Faces

Heat generated by friction between faces of mechanica l seals is a major factor that causes deterioration of the seals and shortens th eir service life. Excessive temperature rise can greatly alter the seal geometry and vaporize the sealing fluid, resulting in friction of boundary lubrication. These effects on face seals usually lead to excessive leakage and ultimately ren der the seal inoperable. In order to maintain the reliability of seals, high fri ction and unwanted wear must be avoided. Using the l...     

Study on estimate method of wave velocity and quality factor to fault seals

Based on ultrasonic test of fault rocks, the responses for wave velocity and quality factor （Q value） to lithology, porosity and permeability of fault rocks and mechanical property of faults are studied. In this paper, a new quantitative estimate method of fault seals is originally offered. The conclusions are as follows： （1） Wave velocity and Q value increase and porosity decreases with the increase in stress perpendicular to joint; （2） In compressive and compresso-shear fault rocks that are obviously anisotropic compared with their original rocks, the wave velocity and Q value are greater in the direction parallel with foliation, and usually less perpendicular to it. In tensile and tenso-shear fault rocks that are not obviously anisotropic, the wave velocity and Q value are under that of original rocks; （3） In foliated fault rocks, the direction with minimal wave velocity and Q value is the best direction for sealing; on the contrary it is the best for flowing; （4） Structural factures develop mainly along foliation, the minimal wave velocity and Q value reflect the flowing capacity in parallel direction to foliation, and the maximal wave velocity as well as Q value reflect the sealing capacity in normal direction to foliation. The new estimate method is based upon contrast of wave velocity and Q value between fault rocks and their original rocks, and is divided into three parts that are respectively to identify rock＇s lithology, to judge mechanic property of faults and to Judge sealing capacity of faults. Although there is vast scale effect between ultrasonic wave and seismic wave, they have similar regularity of response to fabric and porosity of faults. This research offers new application for seismic data and petrophysical basis for seismological estimation of fault seals. The estimate precision will be improved with the enhancement of three-dimensional seismic prospecting work.     

The biochemistry of natural fasting at its limits

There are several groups of animals that are adapted for extremely long duration fasting as part of their reproductive cycle. Penguins, bears and seals routinely fast without food or water for months at time. However, they do not starve, as the biochemical implications of starving are very different from those of successful fasting. There are distinct biochemical adaptations in lipid, carbohydrate and especially protein metabolism that allow these animals to survive. It appears, at least for penguins and seals, that the duration of the fast may be limited by changes that occur in biochemical regulation near the end of the fast. In all of these species, the biochemistry of fasting and the ecological and behavioral demands of their breeding cycles are closely interrelated.     

完美量子封印的攻击策略

提出了一个完美量子封印的攻击策略,利用该策略能成功逃脱系统的监测.构造2个完整的项目操作符,在没有给定基础的情况下可以解码密封消息,并擦除窃听动作.攻击策略在测量过程前后都没有带来任何变化.     

螺旋槽干气密封润滑气膜角向涡动的稳定性分析

螺旋槽干气密封操作的稳定性和可靠性与其槽形参数密切相关,优化槽形参数一直是该领域研究的热点。应用PH线性化方法及变分运算干气密封螺旋槽内瞬态微尺度流动场的非线性雷诺方程,得到了气膜角向涡动刚度的解析式。继而利用复数转换和迭代法对稳态下气膜边值问题进行求解,求得了气膜涡动刚度的近似解析解。通过动态稳定性分析,获得了不同介质粘度、压力和转速下稳定性最佳的螺旋角数值。研究结果表明：随介质压力和转速增大,气膜涡动刚度越大,稳定性越好。     

变压机械密封的研究

探讨了变压机械密封的设计方法，并通过对密封端面润滑状态的分析，提出了一种计算平衡比Ｂ的方法，其计算值与试验值基本符合，应用该法设计的变压机械密封具有良好的密封性能。     

Photoshop软件在印章印文真实性检验中的应用

Photoshop软件是目前市场上最流行的图像处理软件之一,以其强大的功能以及易学易用、效果直观等特点深受用户的青睐.利用Photoshop软件的某些功能可以对可疑印章印文的真实性进行检验.