节能型全倾斜隔仓板在水泥管磨上的应用

前言 管磨在我国水泥行业中被广泛采用,其电耗量占产品总耗电量的75％左右,人们为了降低能耗,提高台产,不断更新改造,通过“以破代磨、优化级配、加强磨内通风、流程合理化,操作自动化”等措施,取得了可喜的成效,但是,正垂直中隔仓板使用至今,虽作了多次的技术改造,仍然存在以下问题:分级能力差,

有线电视系统基础工程(10)

作为弥补同轴电缆传输损失的干线放大器的任务,本讲阐述了其增益频率特性及输入输出电平问题。这样做的目的是尽可能在整个频带内均匀地传输优质信号,为此,本讲叙述了电平调整的方法及其与随机噪声的关系。另外,还介绍了表示放大器噪声特性的噪声指数的定义及其与实际放大器构成的关系,而且。还解说了噪声温度。

Numerical simulation of protection range in exploiting the upper protective layer with a bow pseudo-incline technique

The developing processes of stress and deformation fields of a protected layer after mining an upper-protective layer with a bow pseudo-incline technique were simulated to locate the protection region. The pressure relief of the protected layer was analyzed after mining the upper-protective layer. The pressure relief angle along the strike and incline were located according to the roles of protection of the deformation and stress pressure-relief of the protective layer after mining. This results show that the upper-protective layer with the bow pseudo-incline technique have an upper and downside pressure relief angle of 85 and 68 degrees respectively; the distribution of strike pressure relief angles along the pseudo-incline working face is uneven and their values range from 38.3 to 51 degrees. The pressure relief angle of the inclined middle location was the largest. The distribution of the protection region of the upper-protective layer with the bow pseudo-incline teelmique located by practical tests and numerical simulation is essentially consistent, compared with the results obtained by these methods.

Tracking of Flat Belts

When applying fiat belts, correct tracking of the belt through the installation has to be assured. Since flat belts are commonly used for conveying and transmission purposes, tracking systems have been well developed, but the ultimate tracking behaviour of the belt can be greatly enhanced by taking special care in the creation of an adequate tracking mechanism. To obtain long-life operation and full value from the equipment, the correct tracking technique plays an important role. This paper deals with two tracking techniques： The skewed and the angled pulley axis. Numerical simulation results are compared with both measurements and an analytical approach. The advantages of numerical simulation compared to experimental tests are ease, convenience and the absence of any safety risk. Compared to analytical approaches the simulation is used for systems for which simple closed form analytic solutions are not possible.

人生撬棍

【正】 父亲指引我人生路15岁的我初中毕业后面临着是继续上高中还是考技校的人生选择,不知如何是好的我,便去征求父亲的意见。听完我的倾诉,父亲说:“孩子,去考技校吧,像我一样,车、钳、铣、刨、电样样都能拿得起放得下,将来当一名技术精湛的好工人,也一样会有前途的。”父亲是50年代的技校毕业生,如今已是厂的技术骨干。父亲的话在我心中是很有份量的,可我心中久藏的大学的梦想也不是一下子就肯轻易从我脑子里消失的,正在我犹豫不决的时候,发生在父亲身上的一件事情使我一下把选择人生之路的天平完全倾斜到了考技校这一边。父亲所在的化纤厂一台80年代初从西德进口的万能数控机床出了故障。这台用20多万美金买来的高级进口设备。