纳米ZnO的形貌、光致发光性质及反应气浓度分布的研究

采用化学气相沉积的实验方法,以纯Zn粉为锌源,O_2为反应气,N_2为载气,在双管管式炉内制备了多脚结构的纳米ZnO,研究了载气流量对产物形貌和光致发光性能的影响;通过计算流体动力学软件FLUENT对实验条件下管式炉内O_2和Zn蒸汽的浓度分布进行了模拟。实验和模拟结果表明:随着N2流量的增大,O_2浓度减小,产物由钉状多脚结构向针状多脚结构转变;沉积位置处Zn蒸汽的浓度远大于O_2浓度,绿光发射峰主要是由ZnO纳米晶体氧空位引起的,沉积反应主要由O_2控制。     

Flow Field of Circulating Fluidized Bed Reactor with Venturi Inlet Configuration

Different two-equation k-ε models were used to simulate the gas flow field generated by a new type of circulating fluidized bed reactor with venturi gas distributor. The numerical results were compared with the experimental data. It has been shown that the simulation results from the standard k-ε model have the best match with the experimental data. Based on this model, the gas flow field in the venturi diffuser and riser was analyzed by the concept of velocity nonuniformity and dead zone percentage. Both the nonuniformity of gas velocity and the dead zone percentage reach the maximum at the venturi outlet due to the effect of the vortex. At the same time, it provides a good platform for the further optimization of the inlet configuration of circulating fluidized bed reactor.     

苏联“新经济政策”终结的原因及启示——兼与李述森同志商榷

列宁在国内战争胜利后,自觉地把握住了经济文化落后国家如何建设社会主义这一根本问题,努力实现了党的思维方式的伟大转变,对新经济政策问题进行了可贵的实践探索和理论探索。但由于客观历史条件的限制,他只是提出了问题,尚未完全解决问题,历史要求其后继者沿着其思路走下去。斯大林在国内战争胜利后,却未能自觉适应党所解决问题的变化,仍以处理革命问题的思维方式来处理社会主义建设问题,使其得出的理论与新经济政策的实践形成了巨大的反差,于是便终结了它。这启示我们在社会主义建设过程中,必须把握好实践、理论与其思维方式的内在关联,自觉做到实践创新和理论创新的统一。     

Educational Research for Policy and Practice in Japan – With Particular Reference to Youth Education

Based upon the Fundamental Law of Education, Japanese school education system has long been a source of pride for the country as a result of the high school participation rate, the homogeneity of compulsory education throughout the country. However, the confidence of the people in its schools is now showing severe signs of strain and fatigue. In recent years, there have been many reports about the growing seriousness of a number of educational problems having to do with young people in their childhood and adolescence. Since the mid-1970s, a number of problems have been highlighted. They include violent behavior, juvenile crimes, bullying, refusal to attend school, dropping out at secondary level of education, and corporal punishment. Against the above background, based on recommendations from such advisory bodies as the Central Council for Education and the National Commission on Education Reform, the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) has adopted a range of policies and launched a series of educational reform programmes. For instance, what is called “Rainbow Plan”, based on the final report submitted by the National Commission on Education Reform, provides the country with basic guidelines for the educational reform in the near future. Roles of educational research for making policies have been of significance. Research initiated by the National Institute for Educational Policy Research (NIER) and the National Federation of Educational Policy Research Institutes (NFERI) is an example of contributions to the development of educational qualities in the country. This revised version was published online in July 2006 with corrections to the Cover Date.     

骨科教学中情景模拟与PBL模式的结合应用研究

目的:探讨骨科教学中情景模拟与PBL模式的结合应用效果。方法:选择2013级、2014级共224名康复治疗专业(三年制大专)学生,采用电脑随机的方式,将其随机分为研究组与常规组,各组占112名,其中常规组采用传统方法予以教学,研究组采用情景模拟与PBL模式相结合的方式予以教学,利用考核与问卷调查的方式,统计处理两组教学效果。结果:问卷调查结果提示,研究组对教学方法的满意度、课程活跃程度明显优于常规组,有差异统计学意义(p<0.05);考核结果提示,研究组技能操作、理论考核、病例分析以及专科体验等评分,均高于常规组,有差异统计学意义(p<0.05)。结论:骨科教学中情景模拟与PBL模式的结合应用,能够激发学生学习兴趣,进一步提升骨科教学质量以及学生的综合素质。     

切片胡萝卜热风干燥过程中传热模拟分析与试验研究

物料内部湿热扩散过程是干燥设备和干燥技术研究的基础。干燥过程中,物料内部的湿、热扩散是同时发生的,本文综合湿热扩散过程,提出了切片胡萝卜内部传热模型和内部传质模型,运用第三边界条件进行了传热过程的模拟,并作了实验验证。结果表明:模拟值和实测值十分接近,最大相对偏差小于1.8%;因此用该模型模拟胡萝卜片干燥中传热过程是可行的。模拟结果还显示:物料内各处温度变化不同;在整个干燥过程中,各层的温度梯度随干燥时间先变大,随后逐渐变小,到干燥后期,各层温度趋于一致。     

虚拟仿真技术在计算机网络实验教学中的应用

针对高校计算机专业实验教学的现状,在计算机网络实验中引入了虚拟仿真技术,并结合计算机网络课程的实验教学进行实例论证,说明了在计算机网络课程中运用虚拟仿真技术的必要性。     

室内风速模拟的一种数值方法

在风力发电技术的研究中,进行室内试验是最有效率的方法,这样就必须模拟实际风场的风,而自然风具有不确定性,难于精准的构造模型.运用非平稳随机过程的方法,建立基于观测数据的非平稳随机过程的数学模型,运用这个模型和康平风场实际观测数据,进行了风速样本模拟.结果表明,采用本方法只需利用少量的风速观测数据就可以很好的模拟自然风.     

基于Object控件的组成原理仿真系统

研究在硬件仿真系统中的面向对象技术，使用Object控件开发通用型组成原理实验仿真系统，系统设计采用分层结构和面向对象的设计思想，克服了以往组成原理仿真软件通用性差和功能少的缺点，用户既可使用该系统进行模块内部的设计，又可利用封装好的模块控件进行高级设计。该系统采用可视化的图形界面，具有良好的扩充性。     

美国犹太游说集团对国会及美国中东政策的影响

美国长期以来执行亲以色列政策,美国犹太人对此发挥了重要作用。本文论述美国犹太游说集团的内在资源及其对国会和美国中东政策的影响,从一个侧面展示出美国亲以色列政策形成的原因。