Structure, Phonon Vibration, and Spin Correlation of LaBa2Cu3−x Co x O y

Polycrystalline samples LaBa₂Cu_3?xCo _x O _y (0 ≤ x ≤ 1.0) were synthesized by solid state reaction method. The structure, phonon vibration, conduction, and spin correlation were investigated by means of X-ray diffraction, infrared spectra, resistivity, and electron spin resonance. It is found that there are orthorhombic–tetragonal and tetragonal–orthorhombic structural transitions with Co doping, and the conduction behavior changes from metallic to semiconducting. With the increase of Co content, the Cu(1)—O(1) phonon mode around 531 cm^?1 softens, the Cu(2)—O(2) phonon mode around 657 cm^?1 hardens, and the Cu(1)—O(4) mode around 583 cm^?1 is nearly unchanged. The Cu²⁺ spins tend to localize with Co doping. The changes in structure, phonon vibration, and spin correlation with Co doping are analyzed and discussed.     

关于管理信息化工作的思考

本文探讨在管理信息化工作的关键内容,分析了信息、信息工具与管理工作的关系,强调信息数据的重要性。认为信息是管理工作的主要内容,信息的载体从纸张介质向电磁介质转化,信息工具因此发生了重要变化。管理工作是对工作中产生的信息进行处理,信息量的大小决定了组织结构,信息的如何处理决定了管理的工作流程。管理信息化工作要从信息载体变化的前提出发,考虑这个转变所带来的各种困难,充分应用信息工具的各种资源。在管理信息化工作中应考虑企业的成本和效益。管理系统应从业务出发,打破部门的界限,从数据源头开始,着重考虑权限的榨制,增强灵活性和适应性。     

Characterization of indoor wireless channel at 5 GHz U-NII bands

The paper reports on the experiments undertaken at the University of Wollongong to characterise fading profiles and delay parameters of an indoor wireless channels at 5 GHz U-NII bands. The measurements were undertaken at different locations around the campus with results recorded for a post-processing to calculate the Rician K-factor, the level crossing rate and the average fade duration as well as mean excess delay, rms delay spread, and the coherence bandwidth of the channel. The presented measurement results can be useful in developing a Markov chain based model of the transport channel for IEEE802.11a or HYPRLAN-2 networks. The results also indicate scenarios where the coherence bandwidth of the channel is smaller than the width of the sub-carrier OFDM channels in either of the mentioned systems.     

Decentralized overlapping control of a formation of unmanned aerial vehicles

Decentralized overlapping feedback laws are designed for a formation of unmanned aerial vehicles. The dynamic model of the formation with an information structure constraint in which each vehicle, except the leader, only detects the vehicle directly in front of it, is treated as an interconnected system with overlapping subsystems. Using the mathematical framework of the inclusion principle, the interconnected system is expanded into a higher dimensional space in which the subsystems appear to be disjoint. Then, at each subsystem, a static state feedback controller is designed to robustly stabilize the perturbed nominal dynamics of the subsystem. The design procedure is based on the application of convex optimization tools involving linear matrix inequalities. As a final step, the decentralized controllers are contracted back to the original interconnected system for implementation.     

电测技术在人体骨骼力学性能分析中的应用

用电测实验应力分析方法,对人体管状长骨的力学性质,以及骨折的钢板皮外固定治疗中的力学问题,进行测量与分析。其结果对于推进力学理论在医学方面的应用,以及临床治疗骨折,具有实用价值。     

鞍钢3200m3高炉矿槽施工

介绍了鞍钢新1号高炉(3200m3)矿槽结构的设计原理及其所包含的钢结构、混凝土结构施工技术要点和质量控制,并作出了技术经济效果评述.     

我国首个GSM-R系统工程项目的监理实践

由北京全路通信信号研究设汁院设计、北京现代通信信号工稗咨询公司（以下简称现代公司）监理、中铁电气化局集团施工、华为技术有限公司提供设备的我田首个GSM—R工程项目，经过近一年的施工安装调试，已在大秦线上成功投入运营。在北京局和太原局的大力关怀、支持和帮助下，现代公司对此监理项目，直面困难，高度重视，集思广益，认真监理，严守承诺，根据该项目特点和工程实际，制定并落实各项针对性措施，顺利完成了该项目的监理工作，并获得铁道部领导好评。以下就该工程项目的监理实践谈些体会。     

地基平板载荷试验中存在问题及探讨

根据目前地基平板载荷试验中存在的一些问题．提出一些建议供工程检测人员及规范制定单位参考．     

浅议高职高专计算机网络实验室的建设

文章分析了计算机网络实验的建设对于计算机网络及相关课程的必要性,对高职高专计算机网络实验室的建设问题进行了探讨,提出了网络实验室应具备的功能及建设原则,并给出一种较为全面实用的解决方案。