网址导航系统运行速度的改进研究

自从hao123网址导航系统出现以后，各种各样的网址导航系统层出不穷，虽然表面上看起来都没有什么差别，但其使用速度确是千差万别。针对这个问题，本文分别在搜索引擎设计和代码结构设计上进行改进并开发出了相应的网址导航系统——118网址导航系统，通过对该系统的开发与实现过程的介绍，详细地阐述了网址导航系统改进的方法和改进后的效果。     

反应合成法制备Mg-Li基复合材料的热力学研究

反应合成法制备ＭｇＬｉ基复合材料的热力学研究于化顺闵光辉王大庆（山东工业大学，济南２５００６１）（山东师范大学）陈熙琛（中国科学院物理研究所）关键词：ＭｇＬｉ合金自生复合材料反应合成法１引言ＭｇＬｉ基复合材料具有较小的密度、较高的比强度和比刚...     

含铝蠕铁的研究

对稀土及稀土镁处理含铝蠕铁进行了研究。结果表明：含铝铸铁的蠕化范围比普通铸铁的大得多，并对其机理进行了探讨。     

高强度导电铜基复合材料

高强度导电铜基复合材料是一类很有应用潜力的功能材料，本文综述了该类材料的国内外研究现状，并对其设计原理，制备工艺及性能进行了介绍，最后阐述了该类材料的发展方向。     

Cu—Zr基体中Al—Ti—B2O3体系的反应热力学研究

为研究ＴｉＢ２／ＣｕＺｒ 复合材料的增强相在ＣｕＺｒ 基体中形成的热力学条件, 采用ＤＴＡ 分析和不同温度下的热爆试验, 研究了ＡｌＴｉＢ２Ｏ３ 体系的反应热力学行为, 并讨论了其反应合成机制。结果表明： 在１１００℃下, 该体系能自动发生反应, 生成产物为ＴｉＢ２ 和少量Ａｌ２Ｏ３ ; 在较低温度反应时, 产物中存在硼化物过渡相。基于热爆工艺参数, 在ＣｕＺｒ 熔体中制备了ＴｉＢ２／ＣｕＺｒ 复合材料。     

Martensitic transformation and mechanical properties of Ti-rich Ti-Ni-Cu melt-spun ribbon

Martensitic transformation, mechanical and thermomechanical properties of a Ti-rich Ti₅₂Ni₂₃Cu₂₅ melt spun ribbon annealed at a temperature below the crystallization temperature were studied by XRD, DSC and DMA. After annealing the initially amorphous ribbon at 400 °C for 10 h, the ribbon is fully crystallized and exhibits one-stage B2?B19 phase transformation with the temperature hysteresis of 14 °C. The annealed ribbon is composed of B2, B19 and B11-TiCu phase with (001) preferential orientation. On the stress―strain curves, the rearrangement of the martensite variants and stress-induced martensitic transformation are observed below the M_f temperature and above the A_f temperature, respectively. The annealed ribbon exhibits up to 1.6% superelastic shape recovery with small stress hysteresis of 25 MPa. No flat stress-plateau is associated with the superelasticity. The annealed ribbon shows a well-defined shape memory effect during thermal cycling from ?60 to 100 °C. The transformation strain and recovery strain increase with increasing the applied external stress. Under the external stress above 150 MPa, the shape recovery strain is not sensitive to it and keeps stable at about 1.74%.     

Dependence of characteristics of LaB6 films on DC magnetron sputtering power

Lanthanum hexaboride(LaB₆) thin films were deposited on glass substrate by DC magnetron sputtering technology, and the AFM, XRD and scratch tests were used to characterize the deposited films. Influences of sputtering power on the microstructure and the bonding strength between the film and substrate were investigated. AFM observation proves that the dense films are obtained, and the surface roughness is below 4.3 nm. The LaB₆ film shows the crystalline structure with the grain less than 100 nm. The XRD pattern identifies that the crystal structure of the films is in accordance with that of bulk LaB₆, and the (100) crystal face is dominated. The average grain size decreases firstly and then increases with increasing power, and reaches the minimum of 40 nm when the sputtering power is 44 W. Moreover, the intensity of peaks in XRD pattern increases firstly and decreases afterward with increasing power. When the sputtering power is 50 W, the peak intensity reaches the maximum, showing an intense relationship between the power and crystal structures. The scratch test shows that interface bonding strength of the film/substrate is higher at the power of 44 W than the others, due to the formation of the nanosized crystals and their improved surface energy.     

共晶Ga—In合金的液态结构与粘度研究

利用液态金属X射线衍射仪测试了室温下Ga-24.6%In共晶合金的强度曲线、结构因子、双体分布函数以及原子间最近邻距离。结果表明,液态共晶Ga-In合金结构因子的第一峰呈明显的不对称。表明熔体中仍保留有部分Ga的共价键。,建立了共晶Ga-In合金的结构模型。利用此模型计算所得结果与用Gauss分解所得结果吻合良好;利用回转振动粘度仪进行了粘度测量。结果表明,共晶Ga-In合金的粘度值在100－600℃范围内满足指数关系,表明熔体中没有发生结构转变。并给出了其粘度与温度的关系式。     

铸造Al—Li—Cu合金的组合与性能

本文对Al－Li－Cu三元系铸造合金的组织、性能与成分设计进行了研究。研究发现,Al－Li－Cu三元系铸造合金组织粗大,在枝晶间有大量的Cu偏析;粗大的组织严重损害合金的韧性,在时效态,Al－3Li－Cu三元合金的力学性能较高,但申长较低（0．4％）,采用双级时效时,伸长率可达1％。     

CaB6的反应合成

研究了利用CaCO3、B4C粉和活性炭粉制备CaB6粉末的反应合成工艺,X射线衍射分析了不同反应温度和保温时间条件下所生成粉末的相组成,利用扫描电镜分析了所生成CaB6粉末的颗粒尺寸及形貌,实验结果表明,CaCO3－B4C－C系制备CaB6粉末是一种固相反应过程,其间要经过CaB2O6、CaB2C2等过渡相的生成过程,反应合成CaB6粉末的优化工艺是在10^-2Pa的真空条件下,1400℃保温2．5h。所合成的CaB6粉末与原材料B4C粉的形状相似,通过改善原材料颗粒形貌可优化CaB6粉末形貌及性能。