J2EE架构下的移动智能网业务管理系统

首先对移动智能网中目前的业务管理系统的组成及各部分的功能进行了说明,并指出其缺陷,然后给出了基于J2EE(Java2PlatformEnterpriseEdition)架构下的移动智能网业务管理系统的设计和实现,并讨论了其优缺点。     

室温铁磁性Al2O3∶Mn的制备及性质

以Al2O3为衬底利用多能态离子注入法在离子注入设备上制备了一系列具有室温铁磁性的Al2O3:Mn样品.在Al2O3的X射线衍射峰附近发现新的衍射峰,该衍射峰既可能对应一种未知新相,也可能对应Al2O3:Mn固溶体.所有样品都具有磁滞现象和室温铁磁性.     

基于感应叠加原理的充电电源初步研究

高功率转换开关是限制大功率高压脉冲调制器重复运行频率的关键因素。为避免高功率转换开关的使用,开展了基于感应叠加原理的高压充电电源初步研究。建立了构成感应叠加充电电源基本单元的脉冲变压器调制电路的数学模型,确立了变压器磁芯截面的设计原则,以IGBT作为调制器的转换开关,开展了2级感应叠加充电电源的初步实验研究。实验表明与单元脉冲变压器输出电压相比,升压系数接近2,波形没有发生畸变。     

锥形图形衬底上氮化镓薄膜生长和表征

GaN films are grown on cone-shaped patterned sapphire substrates(CPSSs)by metal-organic chemical vapor deposition,and the influence of the temperature during the middle stage of GaN growth on the threading dislocation(TD)density of GaN is investigated.High-resolution X-ray diffraction(XRD)and cathodeluminescence(CL)wereusedtocharacterizetheGaNfilms.TheXRDresultsshowedthattheedge-typedislocation density of GaN grown on CPSS is remarkably reduced compared to that of GaN grown on conventional sapphire substrates(CSSs).Furthermore,whenthegrowthtemperatureinthemiddlestageofGaNgrownonCPSSdecreases,the full width at half maximum of the asymmetry(102)plane of GaN is reduced.This reduction is attributed to the enhancement of vertical growth in the middle stage with a more triangular-like shape and the bending of TDs.The CL intensity spatial mapping results also showed the superior optical properties of GaN grown on CPSS to those of GaN on CSS,and that the density of dark spots of GaN grown on CPSS induced by nonradiative recombination is reduced when the growth temperature in the middle stage decreases.     

Fabrication of ZnO nanorod-based hydrogen gas nanosensor

We report a first work on nanofabrication of hydrogen nanosensor from single ZnO branched nanorods (tripod) using in-situ lift-out technique and performed in the chamber of focused ion beam (FIB) system. Self-assembled ZnO branched nanorod has been grown by a cost-effective and fast synthesis route using an aqueous solution method and rapid thermal processing. Their properties were analyzed by X-ray diffraction, scanning electron microscopy, energy dispersion X-ray spectroscopy, transmission electron microscopy, and micro-Raman spectroscopy. These analyses indicate high quality ZnO nanorods. Furthermore, our synthesis technique permits branched nanorods to be easily transferred to other substrates. This flexibility of substrate choice opens the possibility of using FIB system for handling.

The main advantage of the proposed in-situ approach is a controllable lift-out procedure which permitted us to obtain a 90% success rate for building nanodevices. The fabricated nanosensor uses only single self-assembled ZnO branched nanorod (tripod) to gauge the 150 ppm H₂ in the air at room temperature. The hydrogen sensitivity is in the range of 0.6–2% depending on which two branches to use. The nanosensor has selectivity against other gases such as O₂, CH₄, CO and LPG, which shows sensitivity of <0.02%. The single ZnO branched nanorod sensor can operate at low power of <5 μW.     

灰色预估神经网络在时滞系统控制中的应用

针对过程控制中由于系统时滞引起的建模和控制方面的困难,提出了利用RBF神经网络对系统时滞进行辨识,采用灰色预估器对系统输出进行预测,并以此替代系统未来的实际输出反馈给输入端,最后利用RBF神经网络控制器对系统进行控制,有效地提高了控制器对时滞变化的自适应性。通过在一个具有时滞的加热炉系统中的应用,说明此方法能够克服不定时滞的影响,使控制目标具有良好的动态和静态性能。     

Thermoelectric Properties of Heavy Rare Earth Filled Skutterudites Dy y Fe x Co4?x Sb12

Heavy rare earth element Dy-filled skutterudites (Dy _y Fe _x Co_4?x Sb₁₂) have been synthesized by a melting–quenching–annealing method and sintered by the spark plasma sintering technique. Our results suggest that single-phased Dy _y Fe _x Co_4?x Sb₁₂ compounds could be obtained when the Fe content is less than 1.5. The maximum filling fraction of Dy in skutterudites increases with increasing Fe content. We also found significant lattice expansion induced by Fe substitution at Co sites and Dy filling in the voids. The electrical conductivity, Seebeck coefficient, and thermal conductivity have been measured in the temperature range from 300?K to 800?K. The low-temperature Hall coefficient and carrier mobility are reported in the temperature range from 2.5?K to 300?K. The power factor for Dy _y Fe _x Co_4?x Sb₁₂ increases with increasing Fe content. A significant reduction in lattice thermal conductivity is observed in heavy rare earth element Dy-filled skutterudites due to the low localized vibrational frequency of Dy that effectively scatters low-frequency lattice phonons. The sample with composition Dy_0.41Fe_1.45Co_2.55Sb_12.28 has lattice thermal conductivity as low as 1.05?W?m^?1?K^?1 at room temperature. The thermoelectric figure of merit (ZT) reaches a maximum value of 0.67 at 750?K.     

ATN路由器中路由算法IS-IS的研究与改进

路由算法和协议在路由器中的地位至关重要,文章对路由算法IS-IS及路由算法的效率进行研究和改进,提高了路由器的处理能力和稳定性。     

基于离群点检测的低压台区同期线损异常辨识研究

为缩短电压参量的实际传输距离,加强对同期线损量异常行为的抵抗能力,提出基于离群点检测的低压台区同期线损异常辨识方法.通过定义离群点的方式,确定线损参量的实际分类条件,根据最大负荷损失数值实现基于离群点检测的低压台区同期线损计算.在此基础上,采集大量的线损数据信息,利用核函数实现对辨识参数的优化与应用,完成基于离群点检测...     

激光在运动系统慢性损伤中的应用

运动系统的任何组织都可发生慢性损伤,这类疾病临床极为常见,病程较长,迁延不愈,常使生活及工作受到影响。作者根据He-Ne激光的特点,选择适当的输出功率作病变局部照射及穴位照射(亦称激光针灸)治疗运动系统慢性损伤的9种疾病,并与其它治疗作了对比,结果证实激光有良好的康复作用。