Design and Implementation of Network Interactive Teaching Platform Based on Blog

本文立足于Blog和RSS关键技术，结合人工智能技术打破了传统的教与学的模式，探讨Blog与RSS应用于网络交互教学平台的设计和应用，在体现教师起主导作用的基础下，充分发挥资源共享的优势，提供一个开放的交互平台，让丰富的网络资源成为真正有效的、经过筛选的知识的来源，拓宽了教师和学生的交流空间，给学生一个更加开放的、自主的、协作学习环境，有利于开发学生的创新思维和创造能力，使网络教学上一个新的台阶。 本文首先详细分析平台中的要素和常用的约束条件，分析难点和目标，提出求解方案的总体思路和技术路线。其次，对系统进行需求分析，设计一个基于B/S模式的三层结构的网络交互平台，利用优异的皮肤机制建立博客...This dissertation based on Blog and RSS technology combined with artifical intelligence, which breaks the traditional education system, discusses the design and application of Blog and RSS in the Internet-based education platform, to make extensive network of resources to be truly effective and a filtered source of knowledge t and broaden the exchanges of teachers and students, and extend the com...学位：工程硕士院系专业：软件学院_工程硕士(软件工程)学号：X200923013

一种利用激光冲击强化技术在工件表面制备涂层的方法

本发明公开了一种利用激光冲击强化技术在工件表面制备涂层的方法，属于材料改性技术领域。该方法首先在激光冲击强化过程中用的吸收层材料上均匀涂敷涂层粉末；将涂敷涂层粉末的吸收层材料贴敷在待喷涂工件上，采用脉冲纳秒Nd:YAG激光器对吸收层进行激光冲击强化处理，激光经过光束整形后输出，将吸收层表面的涂层粉末冲击嵌入工件表面，从而在工件表面制备所需要涂层；该方法制备的涂层均匀，与基材结合强度高，不受工件形状的限制，适用于在形状复杂工件表面制备涂层

EVALUATION OF TYPHOON DISASTER RISK IN GUANGDONG PROVINCE

利用1951—2010的台风数据和2010年人口及统计数据，结合国内灾害系统理论和国外通用风险评估公式，对广东省各市台风灾害风险进行评估，并应用GIS技术分析各个指标的分级分布情况。通过建立台风路径缓冲区，并根据计算灾次比的方法评估台风灾害的危险性；利用各市总人口数和生产总值表示暴露程度，选取5个指标分别表征人口和社会资产两种承灾体的敏感性；再结合暴露度和敏感性得到承灾体脆弱性指标；最终由灾害危险性和承灾体脆弱性两项指标综合计算出广东省各市的台风灾害风险性。结果表明：台风对广东省的影响程度总体上呈现沿海向内陆递减的趋势，粤西沿海台风危险性最高；广州、湛江人口暴露度最高，广州、深圳社会经济资产暴露度最高；人口敏感性指数等级高的城市人口总抚养比值高、女性所占人口比值高、人均可支配收入相对较低，社会经济敏感性指数等级高的城市往往经济发展水平相对较低；湛江、汕尾等城市人口数目多和人口敏感性高从而人口脆弱性很高，广州、东莞等经济发达的城市虽然社会经济敏感性低，但高的暴露值导致其脆弱性值很高。根据评估结果，当前广东省台风灾害风险值最高的城市为湛江、广州和佛山。The typhoon disaster risk in Guangdong province is evaluated according to a general risk assessment formula by using typhoon data during 1951-2010 and population and statistical data of 2010. GIS technique is also applied to analyze the classification and distribution of each index. We evaluate typhoon disaster risk by establishing typhoon path buffers and calculate the typhoon hazard index. The population and GDP are used to indicate disaster exposure. Five indicators are selected to characterize susceptibility of two receptors, population and social assets. Then the vulnerable index is calculated by using the above results. Finally, the risk of typhoon disasters of Guangdong Province can be calculated by the index of hazard and the index of vulnerability. The results show that： the impact of Typhoon on Guangdong Province shows a decreasing trend from western Guangdong coastal to the inland, and coastal typhoon risk is the highest; exposure of population in Guangzhou and Zhanjiang belong to the highest level, while exposure of economic and social assets in Guangzhou and Shenzhen is classified into the highest level; cities with higher level population susceptibility index tend to have higher dependency ratio, women population ratio and lower disposable income per capita; high value of social assets susceptibility index means relatively low level of economic advancement; with high susceptibility, population of Zhanjiang and Shanwei is the most vulnerable, and the well-developed cities, such as Guangzhou and Dongguan, though their susceptibility index is relatively low, have very high exposure value so that the vulnerability indexes are relatively high. According to the evaluation, the current three cities with the highest typhoon risk are Zhanjiang, Guangzhou and Foshan. The result of this risk assessment can provide decision support for disaster risk management in Guangdong Province.国家自然科学基金项目（41661144019）;中国清洁发展机制基金赠款项目（2014085）;江苏省气候变化协同创新中心部分共同资

Research of laser shock peening on tungsten

利用激光冲击强化技术，对金属钨进行改性处理，研究了不同方法条件下，材料显微硬度的变化情况，得到了最佳的冲击参数。结果表明，激光冲击区域会发生晶粒的滑移，并产生高密度的位错，经过多次激光的反复冲击使材料内晶粒细化，并且产生新的晶界。当激光输出能量为7 J、脉宽为12 ns、冲击3次，显微硬度的提升相对显著，当冲击次数增加，显微硬度有进一步增加的趋势。在相同实验环境和条件下，当冲击4次时，试样达到最优的显微硬度，但是冲击达到6次时，可见明显裂纹

基于LMD多尺度熵与SVM的往复压缩机轴承故障诊断方法

针对往复压缩机振动信号的非平稳和非线性特性,提出了基于LMD多尺度熵与SVM的往复压缩机轴承间隙故障诊断方法。利用具有保形特性的Hermite插值法替代传统LMD中滑动平均法构造均值与包络函数,提高LMD对非平稳信号的分解精度。以改进LMD方法对各状态振动信号进行分解,依据相关性系数选择其中代表故障状态主要信息的PF分量。利用多尺度熵对各PF分量进行定量描述,并以平均类间样本距离对尺度因子进行优选,得出可分性良好的特征向量。使用SVM作为模式分类器,诊断得出了轴承间隙故障类型。同LMD与样本熵以及LMD与近似熵方法所提取特征向量进行对比,结果表明该方法具有更高的识别准确率

Excellent tensile properties and deformation mechanisms in a FeCoNi-based medium entropy alloy with dual-heterogeneous structures

A dual-heterogeneous structure with both heterogeneous grain structure and coherent L1(2) nano-precipitate was obtained in a (FeCoNi)(86)Al7Ti7 medium-entropy alloy (MEA) after cold rolling, critical annealing, and aging treatments. The volume fraction of the L1(2) phase is found to increase from 0% to 34.5% after aging treatment, resulting in severer heterogeneity. The unaged samples of (FeCoNi)(86)Al7Ti7 MEA are found to have a much better synergy of strength and ductility as compared to the FeCoNi MEA. Moreover, the tensile properties for the aged samples of (FeCoNi)(86)Al7Ti7 MEA with dual-heterogeneous structures are even better than those for the corresponding unaged samples. The hetero-deformation-induced hardening plays a more important role in the aged samples than in the unaged samples, producing a higher density of geometrically necessary dislocations. High density dislocations are discovered in grain interiors for the aged samples and the deformation is dominated by the planar slip in the unaged samples. Meanwhile, a high density of dislocations are observed inside L1(2) nano-precipitates; thus, L1(2) nano-precipitates can be sheared by dislocations, indicating that L1(2) nano-precipitates are strong but deformable. The strong interactions between dislocations and L1(2) nano-precipitates should provide additional strain hardening for better tensile properties in the aged samples

Research on a different method to reach the saturate limit of titanium aluminide alloy surface mechanical and fatigue properties by laser shock process

Laser shock peening is one of the best method to enhance the mechanical and fatigue properties of titanium aluminide alloys. Most research depends on the pressure model produced by Professor Fabrro, based on Von-Mise stress yield standard, when the pressure is 2 Hugoniot elastic limit (HEL), the plastic deformation reaches the maximum limit and when the pressure is 2.5HEL The stress release from the edge of laser shock area, This research discussed the titanium aluminide alloys surface mechanical and fatigue properties after reducing the pressure of laser shock and inducing the repetitions of laser shock properly. When the pressure reached HEL the material began plastic deformation, in the experiment environment there are several factors affect the results, so the pressure should be more than 1HEL and less than 2HEL-2.5HEL. As the same repetitive times the effective of 2HEL-2.5HEL pressure is better than the less pressure but with the repetitive times rise the 2HEL-2.5HEL pressure specimens would be cracked and the less pressure specimens mechanical and fatigue properties still increase. The results show that with inducing the repetitions and reducing the pressure the material surface hardness improved nearly 25% and the fatigue life increase nearly 40% in high fatigue cycle, the microstructure is similar but the less pressure more repetitive times specimens contains dislocation cells. It indicates that with 2HEL-2.5HEL pressure (the maximum plastic deformation) the mechanical and fatigue properties reached to its peak after 3 times LSP and with 1.5 HEL pressure 8 times repetitive laser shock can reach to the saturate limit of the material itself, that means with less pressure and more repetitive laser shock is more accurately to get close to the saturate limit of the material.</p