Application of Gray Linear Programming in Sintering Mixing Calculation

The mixing calculation cannot be restrained by the quantity of return mines. In order to solve this problem, a method that the sintering mixing proportion is optimized by gray linear programming is presented based on the gray system theory and optimal theory. By using this method, the quality of sintering mines is improved and the energy consumption is reduced.

Analysis and Calculation of the Flow Pressure in the Multipoint Steam Injection String of a Horizontal Well

The multipoint steam injection string of the horizontal well is a commonly used downhole component for high efficiency steam injection of the thermal recovery horizontal well. A reasonable layout of the valves to ensure an even steam output of each point is still not well designed. At present, a general design method which is urgently necessary isn＇ t applied by each factory. According to the balance relationship of the momentum, the energy and the mass of the fluid flowing in the string, the pressure distribution equation of the fluid flowing in the multipoint steam injection string is built. On the basis of this equation, the design calculation method of the multipoint steam injection string is come up with. A specific example is given in the paper. Study shows that, with the equation built in this paper, the string can be designed with each axial valve having the same output, so that the technical demand of an even steam injection of the horizontal well section can be met.

Formal Calculation and Invariant-Based Validation Establish Dependable Algorithmic Programs

The paper presents a formal and practical approach to dependable algorithm development.First,starting from a formal specification based on the Eindhoven quantifier notation,a problem is regularly reduced to subproblems with less complexity by using a concise set of calculation rules,the result of which establishes a recurrence-based algorithm.Second,a loop invariant is derived from the problem specification and recurrence,which certifies the transformation from the recurrence-based algorithm to one or more iterative programs.We demonstrate that our approach covers a number of classical algorithm design tactics,develops algorithmic programs together with their proof of correctness,and thus contributes fundamentally to the dependability of computer software.

基于STEAM理念的“Python程序设计”课程实验案例设计与实践——以股票K线图和均线图绘制为例

针对非计算机专业“Python程序设计”课程,文章探讨了基于STEAM理念的实验案例设计问题。通过实验案例及教学模式设计将程序设计知识与其他学科知识进行跨学科融合,以股票K线图和均线图绘制为例,旨在探索如何以STEAM理念指导实验案例设计,从而通过案例实践提高程序设计类课程的教学质量,进而达成教学目标。

Calculation of the Choked Back Pressure for Steam Turbines with Air Cooled Condensers

The choked back pressure characteristic of the steam turbine unit with air cooled condenser is very different with the unit with wet cooling technology, and the understanding of the choked back pressure performance change with operation load is important to guide the economic operation of the unit. One simplified Variable Operation Condition Analysis Method was put forward for calculation of the unit output-turbine back pressure characteristics. Based on this method, the choked back pressure for each operation load can be determined. An example was given for a super-critical, regenerative single-shaft, 2-casing with 2-exhaust steam turbine generation unit with air cooled condenser. The calculation result was provided and compared with the result of the unit with wet cooling technology.

Algorithm research of the SQP method used in roll schedule calculation for Baosteel's 5m heavy plate

Loading distribution for heavy plate mill is to find optimal control solutions under the granted performance indicators and constraints including mill capacity and hypothesis of rolling models.The solutions are quite different for different performance indicators.In the article,the performance indicators and sequential quadratic programming(SQP for short below) methods employed in 5 000 mm heavy plate mill of BaoSteel are penetratingly analyzed.Generally,the SQP method is an effective and fast way to solve the nonlinear programming problems with small or medium scale constraints.Early in 1976,Han put forward the SQP method for the first time and Powell made it perfect and accomplished the algorithm in 1977.In fact, SQP method was to turn a nonlinear programming problem to a series of sub set of quadratic programming problems.In the algorithm,each iteration step is to solve one quadratic programming problem.The optimal solutions will be gradually approached after quadratic programming problems were totally solved.When solving the quadratic programming problem,the active set strategy were employed which turned the constrained quadratic programming problem to unconstrained quadratic programming problem.The active set strategy made the whole quadratic programming problem be solved by a least square problem.And finally, the matrix of the least square problem would be decomposed by Q matrix and R matrix.After Q matrix and R matrix were obtained,the optimal solutions would be finally found.For loading distribution,the performance indicators were composed by plate shape and draft of each pass.Plate shape is represented by rolling force gradually reduced pass by pass with a tunable factor.The mill capacity is another performance indicator represented by draft of each pass.For heavy plate mill,the mill capacity here is the motor moment. For heavy draft,the motor would be overloaded especially for the first several passes;for small draft,the motor would be loaded slightly.All these would not be permitted to happen when calculating the loading distribution.The mill capacity indicator made the loading of mill just be in the middle,not too much and not too low.In the article,these two performance indicators were analyzed in detail.Examples of loading distribution results with different performance indicators were given by the SQP method.When making changes to the performance indicators,there would be different solutions to the loading distribution.For the optimal solutions to the mill,there was supposed to make changes to the factors of the performance indicators or upgrade the accuracy of the mathematical models of the rolling process.

CALCULATION OF ADIABATIC TEMPERATURE THROUGH COMPUTER PROGRAM IN PROCESS OF COMBUSTION SYNTHESIS

The adiabatic temperature in the process of self-propagating high temperature synthesis iscalculated through FOXBASE language program on the base of establishing thermodynamic datapool concerned.The adiabatic temperature of some common self-propagating high temperaturesynthesis has been calculated,and the computed results are compared with the adiabatic tempera-ture reported.At the same time,the curve about the influence of preheating temperature andadding diluent on Tadis drawn as an example.

融合STEAM的青少年智能编程机器人创客教育研究

设计融合STEAM的青少年智能编程机器人创客教育的实施方案,通过四个“小车主题”课程案例,展示如何运用循序渐进、层层加深又互相联系的方法培养青少年的逻辑和编程思维,提高学生的实践创新能力。

基于STEAM教育理念的机器人课程教学模式构建

本研究通过对STEAM教育与机器人教育的相关概念解析,在STEAM教育理念的指导下,构建了适合我国高校机器人课程的教学模式,该模式以STEAM教育理念的五个维度,以及两个项目活动作为教学内容.其目的是促进学生动手能力、创新能力、计算思维能力等方面的发展.本文从教学目标、教学内容、教学流程和教学评价等方面为当前高校机器人课程教学提供模式参考.

Simulation analysis of static and dynamic characteristics of once-through steam generator in concentric annuli tube

The once-through steam generator (OTSG) in concentric annuli tube is a new type of steam generator which applies double side to transfer heat. The heat flux between the water of centric tube, outside annuli tube and that of annulus channel is assumed to be equal, and then the steam generator’s model is built by lumped parameters with moving boundary. In the basis of the built model, static and dynamic characteristics are analyzed. The static characteristics are proved by experiment results in a 19-tube once-through steam generator of Babcock & Wilcox. The characteristics that the lengths of three regions (subcooled region, nucleate boiling region, superheat region) change with power can be explained by theory analysis. The dynamic characteristics accord with the heat and hydraulics and the results of analysis according to the mechanism.

基于STEAM教育下编程与数学图形认识相结合的教学实践

文章以学生在学习Kitten编程创作《认识图形》的课程为出发点,了解信息技术教学是运用数学或其他学科、领域的学习进行跨学科学习(STEAM教育)的方式,以此加深学生对信息技术在学科学习中的价值理解,推动信息技术与其他学科、领域的整合、实现信息技术作为学习对象与学习工具的双重价值。

韩国STEAM教师专业发展路径研究

概述了韩国培养STEAM专业教师队伍的动机与成就,从国家政策、实践社区、个人教学能力等三个方面探讨韩国STEAM教师专业发展路径,提炼出有利于国内STEAM教师专业发展的要点,以期能为国内教育带来更多有益的思考。

STEAM理念下的动漫课程建设探索——以鄂尔多斯市康巴什区第五小学为例

本文以动漫课程小学阶段STEAM教育研究为载体,分别从STEAM课程的建设框架与理论依据、跨学科整合实践、情境体验与协作性设计、项目设计与成果实证性四个方面来详细阐述具体做法。在课程内容上,艺术融合了美术、音乐等素养课程;工程技术与数学融合了Python编程与简单算法、Scratch模块化编程、3D动漫模型设计与制作等技术类课程;在教学形式上,为更有效进行跨学科教学的课堂实施,积极实践本地化双师授课等新型的教学模式,以此完成STEAM课程理念的本地化实践与推广。

A FUNCTION MINIMIZATION CALCULATION OF CYCLONE 10 MAGNETIC FIELDS

By app(?)ing function minimization calculation method, two function expressions are used to simulate the magnetic field measured for cyclotron Cyclone 10 in azimuth and radius The numerical fitting curves are consistent with magnetic field measured. In most pl(?)es, the accuracies are several thousandth, except those errors to be pointed out in paper.

STEAM视域下小学图形化编程教学设计与实践研究

本研究通过一学期的STEAM视域下的小学图形化编程教学实践,发现在教学中存在以下亟需解决的问题:教学目标失位,导致教学出现两张皮现象;教学内容单一,招致学生学习兴趣低迷化;师资队伍薄弱,致使教学形式化问题凸显。本研究在明确内涵与定位后,构建了教学设计框架,并展示了教学案例,以期为一线教育工作者开展STEAM视域下图形化编程教学提供参考。

A COUPLED THERMO-HYDRAULIC MODEL FOR STEAM FLOW IN PIPE NETWORKS

This article aims to establish a coupled thermo-hydraulic mathematical model for steam network by adopting a set of equations, i.e., the continuity equation, motion equation, energy equation, state equation and enthalpy equation and considering the interaction of hydraulic and thermal working conditions. The model is simplified according to steam flow features in pipe networks. The unsteady flow model is simplified to a steady one with considering engineering practice and the solution to the governing equations are obtained by using the standard fourth-order Runge-Kutta method. Many factors of steam flow are generally considered, such as condensability, change of state, friction and heat transfer in the model. It is concluded that coupled iteration can be employed in steam network thermo-hydraulic computation. The numerical results with the model are basically in accordance with practical operation data.

某600MW机组锅炉主汽出口抽汽方案安全性分析

供热抽汽是形势所趋,本文以某60万千瓦锅炉主汽出口管道最大抽汽量方案进行核算,分别就30%、40%和50%锅炉负荷、在保证发电量不变的基础上,通过壁温计算模型的建立,最终理论计算出三个负荷下最大的理论抽汽量,可为后续供热抽汽改造方案设计提供一些参考。

基于VISUM软件的城市轨道交通线网客流分配自动化计算程序开发

[目的]针对目前城市轨道交通(以下简称“城轨”)线网客流分配计算过程重复性工作较多的问题,基于对城轨线网客流分配过程的研究,开发了城轨线网客流分配自动化计算程序。[方法]梳理了城轨线网客流分配自动化计算程序的开发需求。介绍了基于VISUM软件的城轨线网客流分配自动化计算程序的主要技术流程。基于需求分析,将该程序划分为线网供给方案建模、线网需求方案建模、交通分配计算及数据输出等4个主要功能模块。阐述了该程序中4个模块的操作内容以及参数传递过程。重点介绍了线网供给方案建模模块的计算过程与实现方法。[结果及结论]经实例验证,采用该程序进行城轨线网客流分配的计算,不仅可以满足客流分配所需的复杂的分析计算要求,亦能提高客流分配工作的效率。

基于虚拟编组技术的单线重载铁路通过能力计算方法研究

针对我国现阶段单线重载铁路能力紧张问题,提出应用虚拟编组技术从运输组织层面提升运输能力。对虚拟编组技术基本概念进行介绍,细致分析了虚拟编组技术下列车追踪运行的全过程,将其分为4种状态,并分别给出各状态下追踪间隔计算方法。通过分析虚拟编组技术应用下单线重载线路列车在站作业及会让方式,给出区间运行图周期计算通式,构建虚拟编组下单线重载铁路最小运行图周期计算模型,并将其改写为混合整数线性规划模型。模型结构简单,且规模随区间数多项式有界,可直接采用商业优化软件求解。选取1条实际运营线路进行案例分析,计算结果显示,虚拟编组技术下其通过能力可提升55%,表明计算模型有效可靠,且虚拟编组技术的应用对单线重载铁路能力提升显著。

立式U形管自然循环蒸汽发生器循环倍率近似计算方法研究

循环倍率是保证核电厂立式U形管自然循环蒸汽发生器稳定运行的重要参数。为了近似方便地计算该值,本文在归纳、整理公开出版物中关于蒸汽发生器自然循环相关计算公式的基础上,以典型结构的立式U形管自然循环蒸汽发生器为例,提出一套简单完整的蒸汽发生器循环倍率近似计算方法。在已知蒸汽发生器部分结构参数与少量热工参数的基础上,可按步骤方便地对蒸汽发生器驱动压头与流动阻力进行近似计算,并求解出循环倍率。计算选取的公式均来自公开出版物,仅需水物性表即可完成计算。采用该近似方法的循环倍率求解结果与采用专业蒸汽发生器热工计算程序的循环倍率求解结果相比误差较小。