Influence of Zr dopant on polarization in rutile (In0.5Nb0.5)0.005(Ti1-xZrx)0.995O2 ceramics

(In_0.5Nb_0.5)_0.005(Ti_1-xZr_x)_0.995O₂ (INZT, x = 0-0.10) ceramics were synthesized using a conventional sintering method, and the effects of Zr content on the microstructures, dielectric properties and electron-pinned defect-dipoles (EPDD) polarization of the resultant products were investigated. The solubility limit of INZT was x = 0.075, and a secondary ZrTiO₄ phase appeared at x = 0.10. Ceramics with x = 0-0.10 exhibited excellent dielectric properties, ie, colossal permittivity (CP, εʹ > 10³) and low dielectric loss (tanδ < 0.1), over a wide range of frequencies (10⁰-10⁶ Hz at 300 K) and temperatures (50-350 K at 1 kHz). The dielectric spectra and XPS results confirmed that the CP property of the ceramics could be ascribed to their EPDD polarization. The activation energy (E_a) for EPDD polarization was continuously enhanced by increasing x values. EPDD relaxation parameters at different x values were revealed using Cole-Cole equation fitting. Moreover, α, which characterize the relaxation time τ distribution, increased with x values, thus indicating that Zr was involved in and affected electron localized states. The high E_a, temperature T_p of the peak εʹʹ at 1 kHz, and dielectric relaxation time τ_p at 30 K were related to increases in hopping distance of electrons among defect clusters with Zr addition.     

水样中硫酸根离子的测定方法

提出了以乙醇为介质，钍试剂作指示剂，亚甲基蓝溶液作衬色剂，用氯化钡标准溶液作滴定剂，测定水样中硫酸根离子的方法。该方法可简便、准确地测定各种水样中的硫酸根离子     

基于模糊神经网络的石英加速度计的温度控制

提出了基于模糊神经网络的石英加速度计的温度控制系统.该系统包括模糊神经网络的温度控制软件设计和基于数字信号处理器和可编程逻辑器件(DSP+ FPGA)硬件开发平台的电路设计.模糊神经网络的反向学习过程采用离线学习方法在matlab7.0中进行;根据所设置的样本点对网络参数进行训练,然后把参数训练好的模糊控制程序写入温度控制单元DSP6713中,实现系统的温度控制.实验结果表明,该系统具有响应速度快,稳定性好,控制精度高等优点,其温度控制精度达到0.2℃,满足系统的实际应用要求.     

Lamb波与瞬时相位技术在损伤识别中的应用

采用主动Lamb监测技术与瞬时相位相结合的方法对复合材料板进行健康监测。首先通过仿真试验,模拟损伤信号在正常信号中的叠加,结果表明其会引起瞬时相位曲线相应的变化;然后再利用Lamb波主动监测技术,在复合材料板上进行试验采集信号,其瞬时相位能够发现板结构中的损伤,说明瞬时相位可应用于结构的损伤识别。     

《CLP—Ⅲ》型低压铸造液面加压控制系统的研制及应用

本文用数学语言论证了低压铸造液面加压控制过程中的各种参量之间的关系。由此设计出《CLP-Ⅲ》型控制系统,并通过冷态实验及生产实际考验,证明其理论分析是正确的设计是成功的。     

压铸件中破碎激冷层的研究

本文通过电镜进行金相分析,观察了重量为0.24～4.8公斤的铝合金压铸件的金相组织,并测定了压铸过程中金属液温度的变化,发现了破碎激冷层的存在。探讨了破碎激冷层的生成机理、影响因素及其对压铸件性能的影响。在国内尚未见这方面的研究成果,这项研究对降低由破碎激冷层造成的废品,提高经济效益等都有重要的意义。     

全息干涉的物光研究

本文采用一种比较简单的新方法,即对物光进行部分遮挡,提高了再现光的衍射效率,明显地改进了全息照相实验的再现效果.     

An integrated runtime QoS-aware middleware framework for distributed multimedia applications

Future-generation distributed multimedia applications are expected to be highly scalable to a wide variety of heterogeneous devices, and highly adaptive across wide-area distributed environments. This demands multiple stages of run-time support in QoS-aware middleware architectures, particularly, probing the performance of QoS parameters, instantiating the initial component configurations, and adapting to on-the-fly variations. However, few of the past experiences in related work have shown comprehensive run-time support in all of the above stages – they often design and build a middleware framework by focusing on only one of the run-time issues. In this paper, we argue that distributed multimedia applications need effective run-time middleware support in all these stages to be highly scalable and adaptive across a wide variety of execution environments. Nevertheless, the design of such a middleware framework should be kept as streamlined and simple as possible, leading to a novel and integrated run-time middleware platform to unify the probing, instantiation and adaptation stages. In addition, for each stage, the framework should enable the interaction of peer middleware components across host boundaries, so that the corresponding middleware function can be performed in a coordinated and coherent fashion. We present the design of such an integrated architecture, with a case study to illustrate how it is simple yet effective to monitor and configure complex multimedia applications.     

立式旋涡流化床悬浮空间颗粒浓度场的研究

本文通过实验，利用微机在线测量系统对旋涡流化床悬浮空间颗粒浓度场进行了测试和分析，得出了有利于稳定燃烧的几点结论。