Preparation of carbon encapsulated iron nanoparticles with very thin shells by DC arc discharge

Carbon encapsulated iron nanoparticles(CEINPs) with very thin shells and good core-shell structures were prepared by DC arc discharge at argon intake temperature(AIT) of 800 ℃. The results of high resolution transmission electron microscope(HRTEM), energy dispersive X-ray(EDX) spectroscope, X-ray diffraction(XRD), and X-ray photoelectron spectroscope(XPS) characterizations on the product B show that the thickness of the carbon shells of CEINPs in the product B is in the range of ca. 0.5—5.3 nm, i. e., which can be as thin as only two layers of graphite. The average diameter of the CEINPs is about 24. 7 nm. The total content of Fe element in the product B is 77.0 wt%. The saturation magnetization(Ms) and coercivity(Hc) of the product B are 107.4 emu/g and 143 Oe, respectively. The formation of the CEINPs in the product B is discussed briefly.     

TARGET模型在大学英语课堂网络生态化建设中的应用与研究

基于教育生态理论探讨外语教学网络化建设的实践问题.提出为了建设大学英语网络生态化课堂的运行机制,课堂教学的组织形式可以围绕一个注重教学生态个体和生态环境协调共生发展的TARGET模型逐渐展开.通过行动研究发现,只有在大学英语课堂网络生态化建设中充分发挥好课堂生态系统三个要素(教师、学生、环境)的能量和功能,才可能实现个性的、互动的、立体的生态构建.     

基于工作过程的通信工程项目管理实训系统

对通信工程项目管理的内容进行了分解和优化,基于项目管理的工作过程和核心业务模块,开发了通信工程项目管理实训系统。该实训系统可以模拟通信工程项目前期阶段、设计阶段、招投标阶段、实施和项目监理阶段、验收阶段的工作,可改善通信工程专业类实验教学环境,使实训模块与通信工程真实项目对接,增加学生参加实践的机会,对提高实验教学质量、提高学生的实践能力大有裨益。     

材料、易耗品与低值耐用品信息化管理与实践

材料、易耗品与低值耐用品具有数量广、种类杂、批次多、价值低等特点,管理相对复杂。通过建设信息系统实现对材料、易耗品与低值耐用品的统一登记和管理,建立电子账目,提高了管理效率和管理水平。     

“幼儿集体舞”编舞技法的教学探索

针对目前教学目标定位不准、教学内容择选不恰当、教学方法单一、教师自身创编功底受限等因素所造成的教师难教、学生不爱学的"幼儿集体舞"创编课堂教学困扰,提出从兴趣培养、模仿学习、改变练习、自主探究、作业巩固等几方面来解决的教学策略,以优化教学过程,提高教学效率。     

Writing Dinosaur Large and Mosquito Small: Prephonological Spellers’ Use of Semantic Information

One influential theory of literacy development, the constructivist perspective, claims that young children believe that writing represents meaning directly and that the appearance of a written word should reflect characteristics of its referent. There has not been strong evidence supporting this idea, however. Circumventing several methodological concerns with previous studies, we examined written spellings of young children who did not yet use letters to represent the sounds of words, that is, prephonological spellers. We identified 38 prephonological spellers (M age = 4 years, 2 months) and measured the area of their writing productions. Prephonological spellers made significantly larger productions for words representing large objects than those representing small objects. This effect held true after controlling for the influences of other variables, including size of writing on previous trials and order of trial in a session. Our results suggest that young children sometimes use drawing-like features to communicate the meaning of words when writing.     

协同视域下的高职院校文化产业人才培养与产教融合研究

我国文化产业的快速发展对人才培养提出了更高要求,协同视域为产教融合下的高职院校文化产业专业人才培养提供了有效的实践路径。协同视域下的高职院校文化产业人才培养,应以生产与教学协同为基础,建立科学的人才培养体系;应立足于区域协同发展战略,确立院校文化产业专业人才培养特色;应格外重视“人”的关键要素作用,开创校企合作全面协同机制。产教融合不是高职教育的新概念,但产教融合的全过程协同与全要素效率提升,值得包括文化产业专业在内的学界和业界持续深入研究。     

数字图像处理技术的综述及其未来发展

本文简述了数字图像的一些基本概念,系统地分析了目前较为成熟的数字图像处理的常用方法、计算机软件开发平台及其应用领域,并提出了数字图像的未来发展方向。     

Finite-time control for soft landing on an asteroid based on line-of-sight angle

Motivated by the requirement for safe and pinpoint soft landing in future asteroids missions, a soft landing control method based on finite-time control (FTC) technique is developed in this paper. Firstly, in order to utilize the design philosophy of cascaded system, the landing error dynamics of asteroid probe are divided into two subsystems, including a position error subsystem (PES) and a line-of-sight angle error subsystem (LOSAES). Secondly, homogeneous system theory is employed to design the control law for LOSAES such that the states of LOSAES will be stabilized to the origin in finite time. For the reduced PES subsystem, a FTC law is designed such that the rest of states will converge to zero in finite time. Strict analysis shows that the whole system satisfies the finite time stability. Simulation results demonstrate that the proposed method provides faster convergence rates and better disturbance rejection properties compared with the traditional asymptotically stable control (ASC) method.     

基于刚柔组合搅拌浆增强重金属离子污水处理

重金属离子污水对于环境的污染巨大,对于重金属离子污水一般采用离子分离的方法将污水中的重金属离子提取出来,然后再对污水进行下一步处理,从而降低重金属离子含量的比例。传统的重金属离子污水处理方法采用同一种搅拌浆进行分离搅拌,由于不同离子量下搅拌浆不同时,对于离子的分离特性不同,受限于搅拌浆的固定特性,无法有效对所有的离子进行最优化分离。提出一种基于离子度分布指导的刚柔组合搅拌浆增强技术,通过对不同重金属离子特性的度分布特性进行研究,提取离子度特性,对于不同的离子,采用不同的度分布指导下的刚柔组合搅拌浆进行离子分离搅拌处理,有效提高不同重金属离子下的分离特性。采用4组不同的离子进行比对测试,采用该方法使重金属离子的平均分离特性平均提高了39%,具有很好的指导意义。