直线式电机在有杆抽油设备中的应用

通过对游梁式抽油机的效率、启动特性与直线式电机驱动的有杆抽油机特性的对比，论述了直线抽油机的优越性及应用前景。     

电潜泵中压变频调速系统的改进

电潜泵中压变频器输出端产生高次谐波和脉冲电流 ,对电潜泵电动机的绝缘性能和轴承寿命造成不利影响。为此 ,提出 3项改进对策 :①采用谐振软性开关逆变电路 ,使功率开关器件在零电压条件下导通 ;②在变频器逆变输出端设置电抗滤波器抑制高次谐波电流 ;③改变电动机内部结构 ,如加大定子槽宽 ,增加转子导条尺寸 ,变星接法为星 角接法 ,采用绝缘轴承等。实践证明 ,采取改进对策后 ,不仅提高了电潜泵的产量 ,而且变频器滤波后电动机端的过电压明显减小 ,电潜泵和电缆的寿命延长     

冷轧带肋钢筋直径与拉丝机卷筒直径的匹配

采用被动式工艺生产冷轧带肋钢筋须经过减径、成型两台轧机连续轧制．要求钢材的秒流量相等，否则将造成断线停产或线材在拉丝机卷筒上打滑，致使卷筒严重磨损．用双层卷筒拉丝机提供动力生产冷轧带肋钢筋时，线材直径与卷筒直径的匹配是在一个小的调整范围，通过轧机拉力控制在一定范围变化，可保证成品尺寸符合公差要求而不产生打滑，从而避免了卷筒严重磨损．     

KZON-50/120空分设备的安装调试及设计改造

在KZON-50/120空分设备的安装调试和试运行过程中,对其机械和电器部分进行了多处改造,克服了原设计中存在的不足之处。改造后,机械和电器性能更加趋于合理,操作简单,便于维护,降低了制气费用,提高了制气纯度和经济效益,保证了空分设备更加安全可靠运行。     

磁场对泡沫钻井液电导率的影响研究

磁处理技术是利用磁场对非铁磁性流体作用．使被作用物的性质产生某些期望的变化，从而改善生产效果和使用效益。磁处理对常规钻井液流变性能的影响研究结果表明，磁化能明显改善钻井液性能。通过研究磁化后泡沫钻井液的性质．测定与控制钻井液的电导率，以便从电测曲线上取得更好的地层特性评价。泡沫钻井液的电导率与密度基本呈线性关系，电导率随密度的升高而变大；磁处理后泡沫钻井液的性质发生明显改变．泡沫钻井液的电导率有不同程度的下降，在磁场强度为100mT、蜂数为2的磁场条件下泡沫钻井液的电导率变化率降低最大，电导率平均下降16％左右。     

Holographic polymer‐dispersed liquid crystal fabrication under electric field

The transmission mode of holographic polymer‐dispersed liquid crystals (HPDLCs) was developed an under electric field. It is reported that orientation of LC molecules under an electric field induces orientation of oligomer molecules giving rise to low off‐state diffraction and small grating shrinkage. Copyright © 2005 Society of Chemical Industry     

Evaluation of Digitally Encoded Layer‐by‐layer Coated Microparticles as Cell Carriers

To obtain more biologically relevant data there is a growing interest in the use of living cells for assaying the biological activity of unknown chemical compounds. Density ‘multiplex’ cell‐based assays, where different cell types are mixed in one well and simultaneously investigated upon exposure to a certain compound are beginning to emerge. To be able to identify the cells they should be attached to microscopic carriers that are encoded. This paper investigates how digitally encoded microparticles can be loaded with cells while keeping the digital code in the microcarriers readable. It turns out that coating the surface of the encoded microcarriers with polyelectrolytes using the layer‐by‐layer (LbL) approach provides the microcarriers with a ‘highly functional’ surface. The polyelectrolyte layer allows the growth of the cells, allows the orientation of the cell loaded microcarriers in a magnetic field, and does not hamper the reading of the code. It has further been shown that the cells growing on the polyelectrolyte layer can become transduced by adenoviral particles hosted by the polyelectrolyte layer. It is concluded that the digitally encoded microparticles are promising materials for use in biomedical and pharmaceutical in‐vitro research where cells are used as tools.     

Note on ‘Construction of Double Sampling s‐Control Charts for Agile Manufacturing’

He and Grigoryan (Quality and Reliability Engineering International 2002; 18 :343–355) formulated the design of a double‐sampling (DS) s control chart as an optimization problem and solved it with a genetic algorithm. They concluded that the DS s control charts can be a more economically preferable alternative in detecting small shifts than traditional s control charts. We explain that, since they only considered the average sample size when the process is in control, their conclusion is questionable. Copyright © 2006 John Wiley & Sons, Ltd.     

钻井液振动筛叠层筛网透筛率的研究

从理论上详细论述了钻井液振动筛叠层筛网对固相颗粒分离的影响 ,首次提出用透筛率的概念定量地描述这一影响 ,并进行了实例计算。研究表明 ,当上下层筛网随机叠加时对透筛率的影响有以下几种情况 :(1)当上下层筛网开孔尺寸相除的余数为零 ,任意组合叠层筛网的透筛率分别为某一常数 ;(2 )上层筛网目数一定时 ,下层筛网目数越大 ,则透筛率越小 ;(3)上下层筛网的目数相差越小 ,透筛率越小 ;(4 )任意目数的上下层筛网随机叠加后 ,其透筛率仅在一个小范围内变化 ,因此任一叠层筛网有其固有的透筛率属性。     

电接点压力表补水泵定压系统的应用

阐述了电接点压力表补水泵定压系统的一些应用问题 ,给出了电接点压力表定压点的上、下限计算公式 ,并提出了该系统补给水泵、补给水箱及安全阀的设计选型方法