1.8m厚混凝土板式结构转换层施工技术

中鸿人和商业广场大厦,将转换层厚板分2次浇筑,并在厚板中增设抗剪钢筋,形成叠合板,重点解决了荷载传递问题,合理安排钢筋施工次序,采用”斜面分层、薄层灌筑、自然流淌,连续浇筑到顶”的方法浇筑大体积混凝土,严密控制混凝土内外温差,使板式结构转换层支撑系统稳定可靠。     

异步传输的分布式铁路10 kV电力监控系统

为解决提速铁路10 kV电力系统运行参数变化快、海量实时数据传输和处理困难的问题,设计研发了实时异步传输的电力远动监控系统.对铁路10 kV电力系统的运行、录波数据的远程传输和海量实时数据的处理进行了分析设计.提出了利用发布/订阅原理进行异步数据传输的模式,考虑到实时数据点多、变化快的特点.建立了实时数据交换的二级缓存...     

系统安全背景下未来智能电网建设关键技术发展方向——印度大停电事故深层次原因分析及对中国电力工业的启示

从外部环境以及内部生产运行中的管理层面和技术层面对本次印度大停电事故的原因进行了深入分析,从管理层面和技术层面分别提出了促进中国电力系统安全稳定运行的基本思路。同时,考虑到电网智能化是未来电网发展的趋势,具有坚强、自愈等特点的智能电网能够有效抵御电网安全风险,提出了基于系统安全的中国未来智能电网建设关键技术发展方向,包括分布式发电并网技术、智能配电技术、智能用电技术和电力系统储能技术,能够为中国下步智能电网发展及电力系统安全稳定运行提供借鉴和参考。     

An Enhanced Jacobi Precoder for Downlink Massive MIMO Systems

Linear precoding methods such as zero-forcing (ZF) are near optimal for downlink massive multi-user multiple input multiple output (MIMO) systems due to their asymptotic channel property. However, as the number of users increases, the computational complexity of obtaining the inverse matrix of the gram matrix increases. For solving the computational complexity problem, this paper proposes an improved Jacobi (JC)-based precoder to improve error performance of the conventional JC in the downlink massive MIMO systems. The conventional JC was studied for solving the high computational complexity of the ZF algorithm and was able to achieve parallel implementation. However, the conventional JC has poor error performance when the number of users increases, which means that the diagonal dominance component of the gram matrix is reduced. In this paper, the preconditioning method is proposed to improve the error performance. Before executing the JC, the condition number of the linear equation and spectrum radius of the iteration matrix are reduced by multiplying the preconditioning matrix of the linear equation. To further reduce the condition number of the linear equation, this paper proposes a polynomial expansion precondition matrix that supplements diagonal components. The results show that the proposed method provides better performance than other iterative methods and has similar performance to the ZF.     

块状磷矿石在磷酸溶液中的溶出研究

磷酸直接与磷矿石反应浸取生产浓磷酸,可以使用较大粒度、低品位的磷矿石,充分利用反应热,不需要浓缩,节约成本.当以18.8%P2O5含量的磷矿石为原料,磷酸量为理论量的2倍时,磷酸直接浸取磷矿石的最佳反应条件为反应温度70℃,时间3 h,磷酸浓度54%P2O5,矿石粒度0.9~2.8 mm;当以22.87%中品位磷矿为原料时,磷酸直接浸取磷矿石的最佳反应条件为反应温度90℃,时间2 h,磷酸浓度45%P2O5,矿石粒度小于0.45 mm,磷酸用量为理论量的4.5倍.     

Power optimization using optimal small cell arrangements in different deployment scenarios

For smooth transition from 4G to 5G, there is a need for optimizing the power in the wireless communication. In 5G, it is expected that the number of users will increase drastically that correspondingly increase the utilization of power in the transmitter and receiver sides. So researchers and academicians are now finding ways to optimize the power. Some optimizing methods like convex optimization are very helpful for optimized algorithm design. In this paper, a proposed mathematical approach for deployment of small cell access point is used for optimizing the power consumption in the massive multiple input and multiple output and small cell scenario. The new proposed mathematical approach will also help in deciding the optimal number of small cell access points and optimal location of these small cell access points for the particular deployment scenario like urban macro heterogeneous deployment scenario in the 3GPP LTE standard and different macro deployment scenario in the ITU‐R M.2135 standard like urban macro, suburban macro, and rural macro, for optimizing the power.     

Proximity effects of a layered periodic structure on miniaturization of patch antennas

A miniaturized microstrip antenna on a planar layered periodic structure is proposed, designed and fabricated. The proposed structure miniaturizes patch antennas in the microwave band. With varying the parameters of the proposed structure, the achieved miniaturization factor can be adjusted in the range 2.6–4.2. Numerical and experimental results are presented. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.     

TLM modeling of a probe‐coupled cylindrical cavity based on compact wire model in the cylindrical mesh

This article describes an implementation of a compact wire model into the three‐dimensional transmission‐line matrix (TLM) cylindrical mesh for the purpose of an efficient analysis of probe‐coupled cylindrical microwave cavity devices. Because of a cylindrical grid structure and empirical nature of the compact model, this implementation has to take into account a change of wire model parameters with a variable cross section of the TLM nodes through which a wire conductor passes. The model accuracy has been experimentally verified and compared with the corresponding results reached by the TLM method based on a rectangular grid in order to consider its advantages. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

Adaptive beamforming of massive MIMO based on DoA in high mobility scenarios

A direction of arrival based (DoA-based) beamforming of massive MIMO was proposed for high-speed railway scenarios.In order to guarantee that the optimal system capacity can be obtained during traveling,an iterative multi-beams scheme was proposed.It aimed to design different beams for different mobile carriage terminals (MCT) respectively.The proposal adaptively selected the number of antennas for each beam,and adaptively designed the number of beams according to system capacity.Moreover,the scheme didn’t need channel state information (CSI) that can reduce system implementation complexity and cost.Numerical results indicate that the proposed scheme is suitable for high-speed scenarios,the system performance can be improved more efficiently compared to conventional methods.     

工业建筑大体积混凝土结构裂缝控制设计探讨

大体积混凝土结构的裂缝控制涉及到结构设计、施工、工程管理等各方面,依据多年的实践经验,对裂缝控制设计的若干问题进行总结和探讨,包括对大体积混凝土结构特征的判定、裂缝控制方法的选择、材料的选择、温度应力的控制以及结构方案和构造措施等,可供设计、研究参考。