Smart elasto-magneto-electric （EME） sensors for stress monitoring of steel structures in railway infrastructure     

Yuan-feng DUAN  Ru ZHANG  Yang ZHAO  Siu-wing OR  Ke-qing FAN  Zhi-feng TANG 《浙江大学学报(A卷英文版)》2011,12(12):895-901

Steel structures are widely used in railway infrastructures. Their stress state is the most important determinant of the safety of these structures. The elasto-magnetic (EM) sensor is the most promising for stress monitoring of in-service steel structures. Nevertheless, the necessity of magnetic excitation to saturation due to the use of a secondary coil for signal detection, keeps from its engineering application. In this paper, a smart elasto-magneto-electric (EME) sensor using magneto-electric (ME) sensing units to take the place of the secondary coil has been exploited for the first time. The ME sensing unit is made of ME laminated composites, which has an ultrahigh ME voltage coefficient and can measure the magnetic induction simply and precisely. Theoretical analysis and characterization experiments firstly conducted on the ME laminated composites showed that the ME sensing units can be applied in the EM sensor for improved performance in stress monitoring. A tension test of a steel bar was carried out to characterize our smart EME sensor and the results showed high accuracy and sensitivity. The present smart EME sensor is a promising tool for stress monitoring of steel structures in railway and other civil infrastructures.  相似文献   

“气味”在跨文化交际中的作用     

赵军 《北京城市学院学报》2011,(5):90-94

随着中国与世界各国之间交流的日益频繁,跨文化间的差异与冲突也凸显出来.如何顺利地进行跨文化交际,克服交际过程中出现的障碍是跨文化交际取得成功的关键.跨文化交际不仅仅是语言的交际,更多的是非语言交际.人们的非语言行为与其所接受的文化有着密切的联系.该论文主要从“气味”与饮食、“气味”与文化、“气味”与香水三个方面来解释“气味”及其所属的文化内涵,以及不同国家的人对气味的不同理解和接受程度.  相似文献   

女校大学生就业认知的现状及其对就业心理的影响     

赵淑媛 《中国科教创新导刊》2011,(29):245-246

对324名女校大学生的就业认知现状进行了问卷调查。结果表明女校大学生对就业形势、就业政策以及职业的认知水平还有待提高,部分女生存在自我认知偏差。就业认知是影响女校大学生就业心理的重要因素之一,加强就业认知教育有着十分重要的现实意义。  相似文献   

西部欠发达地区学前教育发展现状与对策——以贵州省为例     

袁川  罗军兵  赵德肃 《安顺学院学报》2011,13(2):45-49

近年来,在政府的大力支持和全省人民的共同努力下,贵州省的学前教育事业得到了健康、快速的发展,社会各界开始重视学前教育,管理逐步规范,办学体制不断得到完善。但在发展过程中也存在一定的困难和问题,如管理制度不够健全、发展不平衡、没有稳定的经费保障、师资欠缺等。因此,结合国家中长期教育发展规划纲要关于学前教育的相关规定,探讨贵州省学前教育发展的目标与措施显得相当重要。  相似文献   

AHP Comprehensive Evaluation on Sustainable Utilization of Water Resources in Hengshui City,China     

潘峰  赵林 《天津大学学报(英文版)》2015,(2):178-182

In order to investigate the sustainable utilization of water resources in Hengshui City, quantitative analysis and comprehensive evaluation on 15 indexes of Hengshui City, such as the perspectives of social and economic development condition, water resource condition, environment condition, development and utilization of water resources,were conducted by using the analytic hierarchy process(AHP) method from 2004 to 2008. Although the sustainable utilization has been growing from 2004 to 2008, the situation and environment of water resources were not optimistic because of the severe water shortage in Hengshui. In the future, improving the supply capacity is the key target for promoting sustainable utilization of water resources.  相似文献   

Low-power three-stage amplifier using active-feedback Miller capacitor and serial RC frequency compensation     

张庚宇  肖夏  聂凯明  徐江涛 《天津大学学报(英文版)》2015,21(6):515-523

A low-power three-stage amplifier for driving large capacitive load is proposed. The feedback path formed by the active-feedback Miller capacitor leads to a high frequency complex-pole but a high Q-value, which significantly deteriorates the stability of the amplifier. The serial RC stage introduced as the second stage output load can optimize the resistor Rz and the capacitor Cz under fixed power and small compensation capacitor Ca, which brings about a suitable Q-value of the complex-pole and the gain-bandwidth product extension of the amplifier. The amplifiers were designed and implemented in a standard 65 nm CMOS process with capacitive loads of 500 p F and 2 n F, respectively. The post-layout simulation results show that the amplifier driving the 500 p F capacitive load can achieve a gain of 113 d B, a phase margin of 50.6° and a gain-bandwidth product of 5.22 MHz while consuming 24 μW from a 1.2 V supply. For the 2 n F capacitive load, the amplifier has a gain of 102 d B, a phase margin of 52.8°, a gain-bandwidth product of 4.41 MHz and a power of 43 μW. The total compensation capacitors are equal to 1.13 p F and 1.03 p F. The better figures-of-merits are 108 750 and 205 113(MHz×p F/m W). The layout areas are 0.064 mm×0.026 mm and 0.063 mm×0.027 mm. Compared with the CFCC scheme, the gainbandwidth product is extended by 1.6 times at CL=500 p F and Ca=1.1 p F.  相似文献   

基于Android的野外地质实习辅助教学系统     

刘晓  张照录  袁晏明  纪玮  张士全  陈丁杰 《中国地质教育》2015,(1):119-120

本研究从野外地质实践教学的特点和需求出发,设计开发了可以运行在Android手机上的野外地质实习辅助教学软件。该系统实现了野外地图浏览、实习路线管理、地质教学点标记、知识点提示、地质现象照片浏览、卫星地图等功能,为野外地质实践教学提供了重要的辅助平台,是实现地质实习辅助教学的一次有益实践,具有一定创新性。  相似文献   

基于大数据的个性化自适应在线学习分析模型及实现     

姜强  赵蔚  王朋娇  王丽萍 《中国电化教育》2015,(1)

通过大数据学习分析模型,能够深入探究学习者的学习过程与情境,发现学习规律,根据每一个学生的需求和能力为其提供个性化自适应学习。本研究综述了大数据的内涵及应用,从微观视角提出了大数据之“大”,不在于其表象的“大容量”,而在于分析数据的全面性和潜在的“大价值”。基于大数据分析,从数据与环境(What)、关益者(Who)、方法(How)和目标(Why)等4个维度构建个性化自适应在线学习分析模型。以《C语言程序设计》课程学习为例,从基于大数据个性化自适应的学习过程结构、学习过程可视化及学习效果实证等方面进行分析,研究结果表明对学生学习行为与知识掌握的数据分析,能够推荐合理的学习路径与恰当难度的学习资源,可对学生的学习效果做及时准确的反馈,提供个性化服务干预,有利于促进教与学。  相似文献   

用户生成性学习资源开发与利用:基于传播要素视角的调查与分析     

黄志芳  赵呈领  邢楠  万力勇  梁云真 《中国电化教育》2015,(2):57-64

随着Web2.0技术的兴起,用户生成性学习资源成为数字化学习资源开发与利用的新视角,对数字化学习资源建设产生了很大影响。本研究基于传播要素视角对用户参与开发利用生成性学习资源的动因和行为进行了调查分析。研究发现,用户由于受自身信息素养、兴趣爱好、平台资源类型和数量、资源的质量等因素的制约和影响,其开发和利用生成性学习资源的行为在驱动因素、参与频度、互动深度等多个维度呈现出不同的水平和特征。提高用户生成性学习资源的开发效率、开发质量和利用效果,应提高用户信息素养、激励用户积极参与、完善资源质量控制机制并建立有效的资源利用模式。本研究对于推动用户生成性学习资源的建设和发展,具有积极的理论意义和重要的实践指导价值。  相似文献   

中等职业教育投入经济增长效应的实证研究——现实困境与突破     

徐晓 《教育学术月刊》2015,(6)

利用1995-2012年的省级面板数据对比分析地方普通高中与中等职业教育投入对经济增长的影响,研究发现:与普通高中教育支出相比,中等职业教育支出对地区经济增长的影响程度较弱,且呈现出明显的地区差异.我国中等职业教育发展中仍存在不少问题,需要不断改革和完善.  相似文献