简论产品定价法

随着社会主义的不断完善，在企业的经营决策中，产品的价格确定是一个十分重要的内容．售价决策正确与否，直接关系到企业经济效益的好坏．本文对产品定价的方法作一探讨，试图找到一种对企业来说比较实用的方法．     

六辊钢带可逆冷轧机传动电控系统

本文主要介绍采用DCS5500B全数字直流传动系统和S7—300程控器等完成的1380mm六辊钢带可逆冷轧机电控系统，详细说明了系统硬件、软件设计。     

建立钢铁主业劳动保护长效机制的思考

建立钢铁主业劳动保护长效机制,是工会组织在促进职业安全健康过程中履行维权基本职责的创新和发展.本文从分析大型钢铁企业的主业劳动保护现状着手,提出创新劳动保护决策、运行和监督机制,把职业安全健康渗透到企业安全管理的全过程,更好地适应国家安全生产管理的转变.     

The virtual cathode velocity during electron beam transport in a drift tube

Technical Physics Letters - A solution corresponding to a thin annular electron beam in a homogeneous drift tube featuring a uniformly moving virtual cathode (VC) has been obtained. The dependence...     

Formation of Quasicrystals and Related Structures in Systems of Aluminum with Transition Metals. Part 1. Binary Systems Formed by Aluminum with 3d Metals

Quasiperiodic phases (quasicrystals) with symmetries forbidden by classic crystallography have been observed in systems of aluminum with transition metals. In binary systems, these phases are metastable; they were obtained for the first time by rapid solidification of melts. We consider the formation of the quasicrystals and we refine the phase diagrams for binary systems A – 3d-M (from V to Ni) in which quasicrystals have been observed.     

Series of Portable Structuroscope-Instruments Based on Measuringthe CoerciveForce

A series of instruments (structuroscopes) assigned for determining various characteristics of materials and products on the basis of the coercive force is described. Main technical characteristics of three types of the instruments are given. The last and most perfect modification is KRM-Ts-K3 instrument. It is provided with a self-contained power supply and has a wide measurement range. It has an internal memory for 4096 measurements and can be connected to a personal computer. Specially designed program software makes it possible automatically to construct graphs. Examples of graphical representation of the measurement data are demonstrated for two- and three-dimensional reproduction of the results.     

Nitrogen utilization and transformation in red soil fertilized with urea and ryegrass

The influence of fertilization with urea and ryegrass on nitrogen utilization and transformation in red soil has been studied by using ^15N tracer method.When urea and ryegrass were applied alone or in combination,the percentage of N uptaken by ryegrass from labelled urea was 3 and 1.7 times that from labelled ryegrass for the application rate of 200mgN.kg^-1 and 100mgN.kg^-1,respectively;combining application of ryegrass and ureareduced uptake of urea N and increased uptake of ryegrass N by ryegrass plant,but the percentage of N residued in soil increased for urea and decreased for ryegrass.when urea and ryegrass were applied alone,the percentage of N residued in soil from labelled ryegrass was more than 69% while that from labelled urea was less than 25%,and much more ryegrass N was incorporated into humus than urea N.     

一种改进的气动弹性时域推进方法

针对气动弹性控制方程,结构项采用标准龙格库塔方法推进,广义气动力项采用时间上的插值技术,发展了一种在每一时间步内只用计算一次非定常气动力的近似四阶龙格库塔推进方法。通过计算非线性Bernoulli方程和某一超音速翼面的气动弹性响应,证明该方法的时间准确度远高于采用气动力冻结技术的四阶龙格库塔方法。其准确度与标准龙格库塔方法相差不大,而其调用非定常气动力求解器的次数仅为其四分之一,大大提高了气动弹性数值模拟的效率。对于一般的气动弹性响应而言,该时间推进方法只用保证每个周期内的时间步在20～30个左右就能满足较高的准确度要求。