基于WEB的校园网交换机端口信息管理系统的设计与实现

随着学校信息化建设的进一步推进,接入校园网的用户数急剧增大,使得大量的交换机端口信息需要统一管理。而传统交换机端口信息由人工管理,这种管理方式存在管理复杂、受交换机所在地点约束、数据易丢失等缺点。探讨了基于WEB的交换机端口信息管理系统的设计思想,并给出了实现方法。     

大类招生背景下的高考成绩标准化探究

高考成绩是大学进行专业分流的重要指标之一,但由于生源地等差异因素导致无法直接对比高考成绩的优劣。本文主要针对省份和文理差异对高考成绩的影响,从分数和排名两个角度对高考成绩进行标准化,在传统线性变换的基础上提出了两段式线性变换方法,并结合有调整的排名正态化得到更为科学的高考标准化分数。     

考研数学中旋转体的体积计算

旋转体的体积计算是考研数学中的一个重要知识点,但一般的教材或考研资料中只给出了计算旋转体体积计算的基本公式,而学生又不能理解这些公式并对其进行拓广,为此,有必要探讨一下旋转体体积的计算方法.     

交叉三角形波纹通道的传热与流动特性的研究

为获得层流条件下交叉三角形波纹通道的传热和流动特性的实验数据,利用热线风速仪和热电偶对流过该设通道的风速和温度进行了测量,在充分考虑入口端流体力学和热力学效应情况下,对周期性通道的实验数据进行处理,并获得平均摩擦因数fD和平均努塞尔数NuD.将实验数据与Fluent数值模拟结果作了对比,误差结果小于±15%.     

实施“高考制＋申请制”并行运作的高考招生改革构想

本文依据教育与心理测量学理论和方法,对目前高等教育"大众化阶段"的高考形式进行了深入剖析。在此基础上,提出了变革传统的"千校一卷"的高考形式,实施"高考制 申请制"并行运作的高考招生制度改革构想:即将高职高专招生考试从目前的高考体制中剥离出来,使高考分为两个层次,一是"本科层次";二是"高职高专院层次";对应目前的高考制度,前者为常模参照考试,主要体现高考的选拔功能;后者为标准参照考试,用申请制替代目前的高考制度。     

大型低速回流风洞换热器设计研究

提出了用于某大气边界层风洞的新型换热装置,设计了一套水循环冷却系统。风洞内换热器是对第3拐角导流片进行特殊设计,该设计突破传统风洞换热器的设计模式,有效地降低了风洞气流的流动损失。在该设计中进行了换热系统的热力学计算、系统结构设计、流动阻力计算等。计算结果表明:对于该大气边界层风洞的技术参数,使用新型导流片换热器,可以使该风洞运转温度保持在25℃左右;该设计对于提高风洞实验数据的精度具有一定的实用价值。     

Effect of terrain and building structures on the airflow in an airport

The aim of this study was to perform computational fluid dynamics (CFD) simulations on the airflows at the Hong Kong International Airport (HKIA). In particular, the effects of hangar buildings and terrain were studied to explore the effects of turbulence on flying aircraft, especially during landing. The CFD simulation showed that significant differences in wind speeds may occur between the north and the south runways on the western part of the HKIA under typhoon conditions with a strong north to northwesterly wind. Simulation also showed that the hanger buildings between the two runways on the western side and the nearby terrain could be causing the observed difference in the wind speeds. The results also indicated that these obstacles could cause significant wind speed variations at the western end of the south runway. This may affect the operation of landing aircraft. The CFD results for a typical typhoon case were analyzed and found to match the wind data recorded by an aircraft landing that day.     

阀门启闭动态转矩测定装置数据采集方案研究

根据阀门启闭动态转矩测定装置设计要求，提出了基于单片机高分辨率模数转换和单片机的数据采集方案。利用Visual Basic6．0提供的MSComm通信控件可以非常方便地编写Windows环境下的串口通讯程序。本文详细介绍了基于PIC16F877单片机的串行数据采集与控制系统实现以及PC机与单片机间串口通讯软件设计。该方法实现简单，功能满足要求，运行可靠。     

高中生数学核心素养发展水平分析与教学建议--2019年高考(天津卷)数学(理工类)考试评价

以2019年高考天津卷数学(理工)试卷实测数据为依据,分析考生从高中入学到高中毕业的数学素养发展情况,着重对数学运算、直观想象和逻辑推理素养的发展水平进行分析与评价,从而得出基于学生数学核心素养发展的教学改进策略。     

中国某传统民居选址对自然通风的影响(英文)

利用计算流体动力学模拟了传统民居当大门建筑群丘陵地形下选址与自然通风的关系.该模拟包括不同气候与地形下的4个案例及其建筑周边风压与风速分布.模拟结果显示:山体能够降低建筑迎风面和背风面的风压绝对值;在有山体的地形中天井对自然通风的促进效果大于没有山体的地形,对比冬季与夏季天井效果时也可得到同样结论;作为障碍物,山体还能降低建筑周边的风速,且由于冬夏季风向不同,山体的影响程度呈现出较大区别.分析结果表明,丘陵位于建筑北向的选址方式可以解决亚热带气候条件下住宅冬夏2季不同的自然通风需求而造成的矛盾,尤其在含天井的住宅中最为显著.     

基于声发射及时延估计的风源系统泄漏定位

动车风源系统专门用于为动车整车制动系统供风,而漏风问题会影响供风效率乃至整个制动系统。旨在利用声发射传感器技术,针对风源系统中最常见的漏风问题进行检测,并利用时延估计技术进行泄漏点定位,从而及时发现泄漏点并采取措施解决问题,以降低风源系统发生故障的风险,减少故障带来的损失。采用小波包分析对传感器采集的数据进行分解重构,以减小外界环境噪音对结果的干扰,最后利用互相关分析及定位公式对漏风点进行定位。仿真实验结果表明,该方法具有较强的抗干扰能力与较高的精度,精度可达到95%左右,因此能较好地解决风源系统漏风定位问题。     

半园式田径场分道前伸数公式的研究

众所周知,传统的田径场地径赛弯道丈量法——“放射法”和“直弦法”存在拉线长,丈量速度慢,使用不方便等缺点。笔者从改革田径场地径赛弯道丈量法的需要出发,摸索研究了分道前伸数的计算公式。 通过列表、画图的比较得知前伸数、分道差、分道前伸数三者之间存在着密切的联系。分道前伸数公式的推导,离不开前伸数和分道差。 本文以求解400米起点线第三道和第四道的分道前伸数为例,得出分道前伸数公式:Ln=(C_1/R(n-1))·d。 最后,应用“角弧法”和“比值法”对公式的准确性进行了检验。本文认为分道前伸数公式的出现,为改革田径场地径赛弯道丈量法提供了条件,同时澄清了某些人对“分道差”的模糊概念。     

湖北省现场统计研究会2010年学术年会会议论文选——基于区组设计的建模评分方式研究

数学建模竞赛试卷的评分方式的合理性与公正性一直是大家关注的焦点.传统的评分方式的最大弊端在于阅卷老师的差异会对试卷的最终得分有一定的影响.根据区组设计的思想,对每位阅卷教师的差异性进行提取,并应用方差分析法进行假设检验.若不同阅卷老师的评分没有显著性差异,就可以用传统的算术平均法计算得分;否则,就应该对学生的试卷得分进行调整,以消除不同阅卷老师评分的差异性,从而保证公平.     

U形渠道断面流速分布规律试验研究

U形渠道是灌区广泛推广的灌溉渠道，其具有占地面积少、水头损失小等特点。但U形渠道流速分布规律及其流量测量仍处于研究阶段。对灌区计划用水、科学用水和节约水资源等工作造成了很大的影响，因此U形渠道测流技术是亟待解决的问题。本文从试验的角度使用断面测流方法，针对三种不同规格的U形渠道测量断面，运用数学拟合方法，探求其流速分布规律，并分析出了相应的U形渠道过水断面流量的积分求和公式，以求对以后的U形渠道量水工作有所帮助。     

浅析俄罗斯高考制度改革

为了适应当今世界的飞速发展,紧跟时代发展的步伐,以及随着国家政治体制的改革与完善,俄罗斯对于高等教育考试制度也进行着不断的改革。通过对俄罗斯高考制度的传统模式、改革原因、改革的目的的研究,以期为我国制定出符合国情的高考制度提供借鉴。     

Algorithm of heating temperature for Chongqing＇s winter greenhouses

Internal temperature is crucial to plant growth in the greenhouse. We investigated the patterns of constructing and managing greenhouses in Chongqing, and developed an algorithm of heating temperature for closed winter plastic greenhouses under the conditions of no man-made illumination, no ventilation and hot wind machine as the heating equipment which are the most adopted pattern of greenhouses in Chongqing area. The algorithm includes two functions of temperature outside the greenhouse, which calculate the values of the warming estimation coefficient （WEC） and the gap between temperatures inside and outside the greenhouse with the measured data of outside temperature, and then give the value of internal temperature; the heat rating of heating facilities required by a greenhouse can be determined by this algorithm with given values of floor area and internal temperature, measured outside temperature and calculated WEC. Verification of the algorithm demonstrates a desirable accuracy of estimation. Algorithms of computing heating temperature for greenhouses of different constructing and managing patterns and in different geographic conditions can also be derived in a similar way. This research presents a paradigm for developing a feasible method to fit out greenhouses with appropriate heating facilities, aiming at energy efficient and cost efficient production.     

Algorithm of heating temperature for Chongqing’s winter greenhouses

Internal temperature is crucial to plant growth in the greenhouse. We investigated the patterns of constructing and managing greenhouses in Chongqing, and developed an algorithm of heating temperature for closed winter plastic greenhouses under the conditions of no man-made illumination, no ventilation and hot wind machine as the heating equipment, which are the most adopted pattern of greenhouses in Chongqing area. The algorithm includes two functions of temperature outside the greenhouse, which calculate the values of the warming estimation coefficient (WEC) and the gap between temperatures inside and outside the greenhouse with the measured data of outside temperature, and then give the value of internal temperature; the heat rating of heating facilities required by a greenhouse can be determined by this algorithm with given values of floor area and internal temperature, measured outside temperature and calculated WEC. Verification of the algorithm demonstrates a desirable accuracy of estimation. Algorithms of computing heating temperature for greenhouses of different constructing and managing patterns and in different geographic conditions can also be derived in a similar way. This research presents a paradigm for developing a feasible method to fit out greenhouses with appropriate heating facilities, aiming at energy efficient and cost efficient production.     

中高考数学试题难度的认知任务分析

本研究根据邵志芳和余岚（2008）设计的CTA评定框架和程序,以李二霞和邵志芳（2009）提出的试题难度多项指标,对近三年（2007~2009）的上海市中考和高考数学试题进行事前难度评定。结果表明：（1）多名评定者对试题的评定呈现极其显著的一致性,进一步验证了CTA方法的信度良好;（2）上海市高考数学试题难度在近三年中呈现“偏难→偏易→偏难”波动,而中考数学试题难度在近三年中则呈现逐年下降趋势。     

Numerical calculation of channel dredging volume using 3D digital stratum model

Prediction of channel dredging volume is critical for project cost estimation. However, many proposed approximate methods are not accurate. This paper presents a novel numerical method to accurately calculate the dredg- ing volume using a 3D stratum model (DSM) and a channel surface model. First, the 3D DSM is constructed rapidly yet accurately from non-uniform rational B-splines (NURBS) surfaces through Boolean operation between a physical terrain model and a stratum surfaces model. Then, a parametric channel surface model is built from cross-section data and a channel center line using code implemented in the VC++ programming language. Finally, the volumes of different types of physical stratums can be calculated automatically and hierarchically to determine the dredging volume. Practical application shows that the DSM method is more precise and faster compared to the section method, and that the implementation of the developed software provides an interactive graphical user interface and visual presentation.     

Classroom Questioning with Immediate Electronic Response: Do Clickers Improve Learning?

A number of studies have focused on how students and instructors feel about digital learning technologies. This research is focused on the substantive difference in learning outcomes between traditional classrooms and classrooms using clickers. A randomized block experimental design involving four sections of undergraduate Operations Management classes was used to determine if clicker systems increase student learning of both quantitative and conceptual material in Operations Management. Learning was measured using the difference between the scores on an entrance examination and the final examination. The findings of this research provide evidence that the use of immediate feedback using a technology like clickers can have a positive impact on student learning as measured by test scores.