金色梦想，一触即发——化学专业校外实践教学基地建设与思考

高等教育要适应世界潮流和时代变化,本科教育须进一步提高实践教学的比重,加强理论教学与实践教学相结合,完善协同育人机制。结合学科发展和企业发展需求,中山大学化学学院与金发科技股份有限公司(简称金发科技)共同建设大学生实践教学基地。本文以中山大学-金发科技本科实践教学基地为例,探讨大学生校外实践基地建设过程中遇到的问题以及实践基地的建设内容与成果体会。     

Estimation of Temperatures in Geothermal Wells During Circulation and Shut-in in the Presence of Lost Circulation

The estimation of temperatures in and around a geothermal well during circulation, and during shut-in conditions in the presence of lost circulation is presented in this work. Estimated temperatures are compared with temperature logs measured during drilling stoppages. Temperatures were estimatted using a computer code specifically developed to account for the transient convective heat transfer due to lost circulation in the rock surrounding a well. This feature of the present code is important since wellbore simulators normally consider the heat transfer process in the rock as a merely conductive problem. The code is capable of accounting for these losses at any point in the well and application was made to the study of two Mexican geothermal wells(well LV-3 from the Las Tres Vírgenes field and well EAZ-2 from the Los Azufres field). The results show that the effect of lost circulation on the shut-in temperature profiles can be modelled satisfactorily. Research is under way to improve the present methodology.     

“三三制”人才培养模式下化学实验教学改革的探索与实践

南京大学国家级化学实验教学示范中心基于"三三制"本科人才培养理念,对化学实验教学进行了改革,完善了"专业学术类"人才培养的实验课程,加强了"交叉复合类"实验课程建设,探索了"就业创业类"人才培养的实验课程及平台建设,取得了显著的建设成效。     

生产率、需求率、变质率及损失率均随时间变化的生产库存模型

建立了生产率、需求率、变质率及损失率均随时间变化的生产库存模型,在假定了(I)变质率线性依赖于时间及库存开始点;(II)损失率线性依赖于时间及短缺量拖后供货的结束点的前提下,给出了寻求最优策略的方法,指出了文[10]中不合理的假设,并以实际的例子与已有结果作比较,其结果为生产管理部门的决策提供了理论依据.     

信息安全风险模型

基于决策分析技术,提出了一种决策驱动的风险管理模型框架,并给出了安全策略纯效益的算法,该模型与目前国内流行的风险模型相比,能定量的分析风险管理,给出有害事件爆发频率和影响程度的具体缩减值以及计算出每个安全策略的纯效益,得到最佳安全策略.     

热机的第二定律效率与不可逆性

利用热机的功－熵关系和可用能概念，给出热机经二定律效率的表达式，同时了热机相对损失功的概念，并用它们比较了几个实际动力源的不可逆程度。     

原木随机存贮策略的最优化问题

本主要介绍原木经销商在周期内原木变价销售情况下的最佳期初贮存量的决策方法，在建立期望机会成本的数学模型基础上，探讨原木随机存贮策略的最优化问题。     

工程教育认证背景下《高分子材料成型加工》教学模式探讨

随着高等工程教育改革和社会发展,工程教育认证已经在我国高等工程专业实施。工程教育认证是高等教育工程观的重要转变,主要倡导学生中心、产出导向、持续改进三个基本理念。本文介绍了常州大学高分子材料与工程专业的专业核心课程高分子材料成型加工的建设与教学改革做法,以学生为中心,以毕业要求达成为目标,从教学目的、教学内容、教学方法和手段、持续改进等方面深程度对课程进行改革与实践,积极探索以学生为主体的教学新模式。     

大学化学先修课程的实践与思考

中国大学先修课程是国内在基础教育阶段探索人才培养的一种新模式,同时也是高校探索通过综合评价选拔人才的途径之一。在连续3个轮次教学实践的基础上,北京师范大学第二附属中学对大学化学课程的目标定位、课程内容、实施方式以及资源建设等方面进行了系统的总结,讨论了目前大学先修课程实施过程中所面临的若干问题。     

On the Number of Lost Customers in Stationary Loss Systems in the Light Traffic Case

For the stationary loss systems M/M/m/K and GI/M/m/K, we study two quantities: the number of lost customers during the time interval (0,t] (the first system only), and the number of lost customers among the first n customers to arrive (both systems). We derive explicit bounds for the total variation distances between the distributions of these quantities and compound Poisson–geometric distributions. The bounds are small in the light traffic case, i.e., when the loss of a customer is a rare event. To prove our results, we show that the studied quantities can be interpreted as accumulated rewards of stationary renewal reward processes, embedded into the queue length process or the process of queue lengths immediately before arrivals of new customers, and apply general results by Erhardsson on compound Poisson approximation for renewal reward processes.