表面效应对YAG:Eu3+纳米晶发光特性的影响研究

分别采用沉淀法和燃烧法制备了YAG:1%Eu3+纳米晶粉末,用XRD和TEM对样品进行了结构分析和形貌表征。室温光谱分析表明,其发射主峰位于590nm,来源于5 D0→7F1跃迁,另外来源于5 D0→7F4跃迁的709nm发射也较强。另外发现,燃烧法制备的样品在不同激发波长激发时,发射光谱峰形有显著变化。对沉淀法制备的纳米微粒经盐酸"浸蚀"表面修饰后,发现395nm激发时,676nm和693nm发光显著增强,而且693nm发射的激发谱中存在两个宽激发带。对表面修饰后样品的变温发光特性研究发现,随着温度的降低,676nm发射显著增强,而693nm发射显著减弱。对于上述现象通过纳米微粒的表面效应和缺陷态进行了分析和解释。     

曲面造型方法的分析与应用

首先对曲面造型的各种方法进行了分析和比较,并进一步说明了实体上曲面创建的一般方法和步骤,然后结合实例对各种造型方法进行了综合应用,有助于提高曲面分析和造型能力。     

QoS-based optimal and fair resource allocation for energy-efficiency uplink NOMA networks

The energy-efficiency(EE) optimization problem was studied for resource allocation in an uplink single-cell network, in which multiple mobile users with different quality of service (QoS) requirements operate under a non-orthogonal multiple access (NOMA) scheme. Firstly, a multi-user feasible power allocation region is derived as a multidimensional body that provides an efficient scheme to determine the feasibility of original channel and power assignment problem. Then, the size of feasible power allocation region was first introduced as utility function of the subchannel-user matching game in order to get high EE of the system and fairness among the users. Moreover, the power allocation optimization to the EE maximization is proved to be a monotonous decline function. The simulation results show that compared with the conventional schemes, the network connectivity of the proposed scheme is significantly enhanced and besides, for low rate massive connectivity networks, the proposed scheme obtains performance gains in the EE of the system.     

基于PLC的板坯过程跟踪系统研究

针对钢铁企业连铸坯料物流信息化现状,根据系统建设情况,叙述了板坯过程跟踪系统组成结构、网络拓扑、软硬件设计以及实施情况。对系统建设和实施过程中的影响因素和完善情况进行了说明,并对设计与实现过程中采用的相关技术与实现方法做了简要阐述。     

诏平台灌区浅层地下水资源量分析

地下水资源量是在地下水不断补给、储存和消耗的循环过程中形成的。从供水和保护环境出发,以及长期稳定开发利用,资源的利用应限于可更新和恢复的那部分水。通过对昭平台灌区地下水均衡趋势的分析计算,计算其各个均衡区补给量、排泄量以及开采量,对以后昭平台灌区节水改造,保护地下水资源及地下水合理开发利用都具有借鉴意义。     

Analysis and direct calculation of the energy migration interaction parameter in high concentration Nd3+ doped YAG laser crystal

The energy migration interaction parameter CDD in high concentration Nd3+ doped YAG laser crystal was estimated using the Yokota-Tanimoto (Y-T) model and the spectral overlap model (SOM) of Kushida, respectively. Firstly, the experimental luminescence decay curves of 4F3/2 state of Nd3+ ions in YAG laser crystal at room temperature for 2.0at.% and 3.0at.% Nd3+ concentrations reported by Mao were fitted successfully using the Y-T model, and the parameter CDD was obtained to be 1.50×10-39 cm6/s. Secondly, the parameter CDD was directly calculated using the spectral overlap model (SOM) of Kushida; CDD was calculated to be 2.73×10-39 cm6/s. By comparing the energy migration interaction parameter CDD with the energy transfer interaction parameter CDA (1.794×10-40 cm6/s), it was concluded that the energy migration rate between Nd3+ ions in YAG laser crystal was about 11 times larger than the energy transfer rate, and that energy migration played a very important role in high concentration Nd3+ -doped YAG laser crystal.     

CeO2∶Er3+纳米晶的合成及上转换发光特性研究

采用燃烧法制备得到CeO2∶Er3+纳米晶粉末.用X射线衍射仪(XRD)、高分辨透射电子显微镜(HRTEM)和荧光分光光度计等对CeO2∶Er3+纳米晶的结构、形貌和上转换发光特性进行了研究.结果表明:所得到的纳米晶粒度均匀、结晶完好,属于立方萤石结构.上转换发光光谱的研究表明:在980nm红外光激发下,可以发现上转换荧光,分别来自于Er3+离子的2H11/2,4S3/2→4 I15/2和4 F9/2→4I15/2跃迁.     

煤炭企业发展循环经济的问题与对策

从煤炭企业具体实际出发,研究煤炭企业发展循环经济过程中存在的内部和外部的问题,针对煤炭企业发展循环经济中存在的问题提出对策和建议,初步探索出一条传统资源型煤炭生产企业依靠自主创新,不断优化产业结构,努力转变经济增长方式,以实现科学发展、可持续发展的新路子。     

模拟退火与蚁群混合并行算法解旅行商问题

求解TSP问题的智能优化算法主要包括蚁群算法和模拟退火算法等,这些算法求解TSP问题的速度比传统的精确求解算法有很大改进,但在问题的求解空间逐渐增加时,串行执行速度往往还是无法满足人们的需求.针对此问题,研究了蚁群算法、模拟退火算法以及两者的混合算法的并行实现方法,建立了PC机群实验平台,基于MPI环境对蚁群算法、模拟退火算法以及混合算法的并行算法进行了测试.根据理论研究和实际测试的结果,比较了并行算法和传统串行算法的性能差异,总结了利用PC机群系统求解旅行商问题的并行求解的可行性,得出了关于并行效率等方面的一些有意义的结论.     

中国古代青铜器纹样在化妆品设计中的应用

中国青铜器文化历史悠久,甚至在世界艺术史上也有着极其崇高的地位。本文通过对青铜器纹样的探索和创新,深入探索古老青铜器纹样与现代化妆品设计的结合点,使之应用于日常生活中。将青铜器纹样及藏品从历史长河中唤醒,步出库房、融入生活、迈出国门,实现让文物“活”起来的目标。让公众在与活态文物的对话中潜移默化地增强文化自信,更为民族化妆品品牌树立国际独特形象,提供具有深厚文化内涵的中国“符号”。