Fabrication of homogeneously dispersed graphene/Al composites by solution mixing and powder metallurgy

Graphene-reinforced aluminum (Al) matrix composites were successfully prepared via solution mixing and powder metallurgy in this study. The mechanical properties of the composites were studied using microhardness and tensile tests. Compared to the pure Al alloy, the graphene/Al composites showed increased strength and hardness. A tensile strength of 255 MPa was achieved for the graphene/Al composite with only 0.3wt% graphene, which has a 25% increase over the tensile strength of the pure Al matrix. Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy were used to investigate the morphologies, chemical compositions, and microstructures of the graphene and the graphene/Al composites. On the basis of fractographic evidence, a relevant fracture mechanism is proposed.     

海南山茶科一新变种

本文描述与说明海南山茶科山茶属一新变种，它就是五指山毛蕊茶．     

电磁继电器触点面的SEM和XPS研究

使用X射线光电子能谱（XPS）和扫描电子显微镜（SEM）等表面分析方法,研究未启封、使用过失失效和使用过失效的继电器触点表面和形貌、组份和结构,结构表明,经过使用后触点表面烧蚀严重并发生磨损,其组份中含Ag、Sn、C和O等原子,C和O的XPS峰显示,触点表面氧化膜和碳化物的形成,导致接触电阻增大,从而影响继电器的稳定履使用寿命。     

新型亲和活性配基及其纯化功能

以Ｄ．Ｓ．Ｄ．酸为桥基，氯三嗪为活性基，对－氨基苯甲酸、对－氨基苄基膦酸、对－氨基苯磺酸为尾基合成了三只对称型无色活性配基，其结构经波谱法及色谱法验证；比较了它们对碱性磷酸酶的纯化功能。结果表明：以苯甲酸及苄基膦酸作尾基者效果较好，回收率达８０％以上；配基浓度及缓冲液ｐＨ值对回收率影响明显。     

连铸小方坯的组织与性能研究

The hot cracking of the continuous casting bullit is connected with its macrostructure and mechanical property burnt. The macrostructure and the mechanical property of 0. 13 wt- %C continuous casting bullit was investigated. The results are as follows: 1) the classical representation of the casting bullit shows three distinct zones, a peripherial region of small equiaxed grains, a columnar zone, and a central equiaxed zone. The rapid increase of the under cooling layer thickness is the criterion of the transformation from the columnar zone to central equiaxed zone; 2) The hardness decreases with the reducing of the solidification speed; 3) The tensile strength decreases gradually from the peripherial equiaxed maximum principal strain zone to central equiaxed zone ,and increases with the drop of the temperature.     

木工压刨床噪声源识别

本文通过对MB10A9型木工压刨床的实验研究,运用现代测试手段和数据处理方法,找出了木工压刨床的噪声源,通过噪声形成机理分析,确定了木工压刨床的声源特性,在此基础上采取了一些降噪措施,并收到了良好的效果。     

Fe—P非晶合金电沉积镀层的制备及其腐蚀性能

本文以电化学方法研制Fe—P非晶合金的电沉积镀层。研究了各种电沉积条件对合金中磷含量的影响。测定了非晶合金的腐蚀性和极化曲线。实验结果指出,在开始阶段合金是活化腐蚀,合金中的磷加快了腐蚀过程,最后磷在表面的富集,使合金进入钝化状态。 对非晶合金电沉积镀层的晶化温度和硬度进行了测定。     

农业地形气候区划的方法及其应用

本文论述了山区农业地形气候区划的原则,方法、指标和等级单位系统,监以福建省沙溪流域为例作了具体应用。文中介绍的山区农业气候资源空间分布的推算方法能有效地揭示山区农业气候资源的宏观与微观分异规律,从而为山区农业地形气候区划的开展创造了先决条件。     

基于SD法的海口骑楼历史街区中山路段的使用评估

为了有利于街区改造,提高空间环境质量和街区形态意识,本文选取海口市骑楼历史街区的中山路街道为研究对象,对其进行了实地调研和问卷调查,同时运用SD法和因子降维分析法,从感性评价到量化分析,从氛围因子、视觉因子、体验因子入手,剖析了游客与居民日常的生活需求,并以使用者为出发点,重塑了历史街区文脉与空间体验感、构成要素和空间...     

SiH_4分子的单脉冲激光光声光谱

本工作测得了在 926.96cm~(-1)～108844.72cm~(-1)波段 SiH_4分子与CO_2激光谱线对应的光声光谱,确定了SiH_4分子的最佳吸收线位置,还用光声谱法测得了声音的传播速度及V-T驰豫时间,验证了在小的光强时光声信号与光强的线性关系.