管窥南朝与北朝对“郡望”的不同态度

虽然＂郡望＂一词对南北朝社会影响深远,但南朝与北朝对汉族大姓望族的认可态度不同,南朝与北朝冒籍现象的程度不同,南朝与北朝的人们对祖籍的态度不同。之所以会出现不同的态度,是因为南朝与北朝政权依靠的力量、迁都的影响以及文化方面存在差异,而且南朝对于墓志碑铭、谱系的管理制度相对北朝也更为健全和完善。     

网络环境下大学英语教师反思能力培养的实效性研究

开展反思性教学是教师专业发展的有效途径。通过一项基于石家庄铁道大学非英语专业部分教师和学生反思网络环境下大学英语教学的行动研究,可以看出网络环境下的大学英语教学急需解决的主要问题是大学英语教师角色的转换、教学课件制作和使用的科学性、网络环境下互动教学的开展。在网络环境下开展大学英语教师反思能力培养的行动研究,对教师的教学能力和专业发展以及全面提高大学英语教学的质量,有着重要的现实意义。     

WPT-based modal control on distributed structures with MRF-04K damper

The magnetorheological (MR) fluid damper-based semiactive control systems have received considerable attention for protecting structures against natural hazards such as strong earthquakes and high winds. In this paper, a novel modal controller using wavelet packet transform (WPT) is proposed for the vibration control of distributed structures. In the proposed control system, the WPT method is utilized to decompose the acceleration measurement and select the modes containing most of the WPT energy component as the dominant modes. Then, a modal controller is designed to control the dominant modes and the optimal active control force is solved. Finally, Clipped-optimal con- trol law is adopted to determine the voltage applied to each MR damper. A Kalman-filter observer, which estimates the full controlled modal states from local accelerometer feedbacks, is designed for rendering the controller to be more applicable to distributed structures with a large number of degrees of freedom. A numerical example of a stadium roof structure installed with MRF-04K damper is presented. The effectiveness of the controller is evaluated under both Tianjin and El Centro earthquake excitations. The superior performance and adaptability of the controller for versatile loading conditions are demonstrated through the comparison with traditional truncated modal controller.     

引力透镜效应在宇宙学中的研究及应用

引力透镜效应已经成为当前探测宇宙中物质分布最有效的工具之一,因其光线偏折不依赖于物质的组分和状态,所以它很适合于探测包括暗物质在内的所有物质在宇宙中的分布.在引力透镜效应的提出及发现基础上,根据引力透镜的分类,分述了强引力透镜、弱引力透镜和微引力透镜,并讨论了引力透镜效应在宇宙学中的应用.     

Experimental performance of moderate and high temperature heat pump charged with refrigerant mixture BY-3

Theoretical and experimental analysis of a new refrigerant mixture BY-3 was conducted based on a single-stage vapor compression refrigeration system. The water-water heat pump system used BY-3 to produce hot water when the low temperature was 20 ℃. The following results were obtained: the highest temperature at the condenser outlet reached about 85 ℃; when the difference between the water temperatures at the condenser outlet and the evaporator inlet was less than 40 ℃, the coefficient of performance (COP) was larger than 4; when the difference reached 55 ℃, the COP still kept 3; the discharge temperature of BY-3 was lower than 100 ℃, and the refrigerant vapor pressure kept lower than 1.8 MPa. When the water temperature at the condenser outlet reached over 85 ℃, nearly a 5 ℃ superheating temperature was maintained.     

科学教育中的迷信及哲学救赎

在我国的科学教育中存在着迷信化现象,主要表现为重结论轻根据,重肯定轻质疑,化多元为一元,视猜测为真理。导致学生偶像重重、思维僵化、不善追问、缺乏创新能力,这与长期以来哲学与科学教育未能有机融合有关。时代呼唤科学与哲学的重新结盟,充分发挥哲学对科学前提和结论的批判、质疑功能。要充分实现这一功能,需要广泛吸收科学哲学的优秀成果,凸显和改进认识论,形成科学友好型哲学,在各科学专业中开设这样的课程,或在科学课程中融入这样的内容。     

基于SPCE061A智能磁性液体表观密度仪控制系统

介绍以SPCE061A单片机为控制器的磁性液体表观密度仪控制系统,用以满足工业设计中复杂的数据采集需要。该系统由SPCE061A单片机控制,通过力敏传感器单元与PC系统通信,设计数据处理方法并编写相应的计算程序和交互式的窗体界面,用户可根据实际测量要求对实测软件进行设置,从而实现对实验数据读取、处理和曲线绘制、显示、打印、保存等功能。同时,用户可远程登录计算机,进入系统设置实测软件,远程进行数据采集,并能得到实时的采集结果,故系统具有扩展性。该系统控制简单、成本低,适用于教学和科研中的数据采集。     

节能型实验用空调制冷机水系统

提出了节能型实验用空调制冷机水系统。充分利用实验装置的冷凝热、制冷量等自身能源,有效地解决了原有实验用空调制冷机水系统存在的问题,同时还减少了自来水的消耗量,并以实验证明了节能型实验用空调制冷机水系统的优点。     

SBR法后续处理垃圾渗滤液的影响因素

为提高垃圾渗滤液处理效果,采用序批式活性污泥法(SBR)对垃圾渗滤液进行后续处理,考察了曝气时间、污泥浓度、沉降时间和pH对SBR工艺的影响.结果表明:经过30 d污泥培养驯化,测得SVIvi＝80～100,SV30＜0.3,MLSS＝2.8～3.0/L,镜检可见大量钟虫、轮虫和原生动物等;在曝气时间8h,污泥浓度3.5g/L,沉降时间2.5h,pH＝7的条件下使垃圾渗滤液中COD由1600 g/L下降到 352mg/L,NH3-N由485mg/L下降到86.8mg/L,SS由260mg/L下降到52 mg/L,去除率分别达到78%,82.1%和80%.     

基于超声波测距的实时路况信息采集系统

基于超声波测距原理,通过AVR单片机芯片计算出道路车辆的实时速度以及车流量。采集到数据后,通过无线模块NRF24L01发送到PC端,在PC上用VB开发上位机,从而显示出实时曲线,道路信息。介绍了系统的硬件及其软件的整体设计理念,注意事项,同时给出了该系统的应用前景。