基于Massive MIMO及频谱叠加的5G SA网络上行优化方法

大规模多输入多输出(Multiple-Input Multiple-Output, MIMO)可以有效提升5G SA网络的上行链路数据传输速率以及可靠性。针对5G SA网络上行链路速率和覆盖不均衡的情况,提出了基于大规模MIMO的分组算法,将发送信号矢量进行分组,组内采用最大似然检测,组外采用基于正交三角分解(QR分解)的干扰消除检测,并且结合5G频谱的叠加策略,在降低算法复杂度的同时,有效提升网络覆盖和速率。通过5G SA现网实测,通过MIMO降低分组数量能够提升分组检测性能,结合上行低频段频谱叠加策略能够有效提升5G SA网络上行覆盖30%,提升5G SA网络上行平均速率40%~80%,特别是弱覆盖边缘的网络速率,最高可达600%。     

机场路水泥混凝土路面维修对策研究

针对机场路水泥混凝土路面的现状、交通量和破坏原因,结合汕头市的技术经济水平和气候条件,提出了3种维修方案,采用现值法对各个维修方案进行经济评价,通过综合对比,推荐最佳的维修方案,以供类似工程参考借鉴。     

深汕高速公路软基段路面处治方案设计

深汕高速公路软基路段经地基加固处理并铺设过渡性路面后投入运营3a,路面出现不同程度破坏。通过调查,软土地基物理力学性能已明显改善,但在重车超荷作用下,过渡性路面承载力不足,加上雨水浸蚀,路面遭受破坏,进行处治势在必行。文章介绍了对过渡性路面改造的补强设计、病害处理和加铺罩面设计方案。实践证明,经处治后路况良好。     

连续配筋混凝土加铺层施工技术探讨

介绍了连续配筋混凝土的施工情况，总结了连续配筋路面施工过程中应控制的因素，以提高连续配筋路面的施工质量，为连续配筋路面在我国的应用提供了施工参考。     

旧水泥混凝土路面加铺沥青层结构设计及防反射裂缝研究

用4种不同方法计算了加铺沥青层结构的厚度,比较计算结果,并综合考虑其他因素进行加铺层结构设计。通过AAPA进行加铺沥青层反射裂缝试验研究。研究表明,所设计的加铺层结构是较为合理的,在加铺层结构中的关键层采用改性沥青是非常有必要的。     

我国省会城市势力圈划分及与其行政范围的叠合分析

用HAP软件对全国省会城市(含直辖市)势力圈进行划分,比较势力圈的面积大小及分布情况,并在势力圈基础上叠加省域行政范围,揭示省会城市势力圈与省域行政范围的相互关系,研究成果可为全国行政区划调整等提供参考。     

核电管道安全端异种金属焊接接头表面堆焊的有限元分析

根据热弹塑性有限元分析原理,建立核电管道异种金属焊接接头表面堆焊修复的有限元模型。应用ANSYS软件模拟某核电厂稳压器安全端接管堆焊修复试验过程,计算分析焊接温度场和应力场及焊接残余应力。结果表明,焊接过程中的不均匀热过程直接引起了复杂的应力状态。焊接过程中,环向应力变化比轴向应力快,环向残余应力比轴向残余应力大。堆焊后,在原管道内表面原焊缝附近形成了压缩残余应力,沿半径方向残余应力由拉应力逐渐向压应力过渡。     

Multidimensional benefit–cost evaluation of asphaltic concrete overlays of rigid pavements

Using the data from a national study in the USA, this study demonstrated a comprehensive and multidimensional pavement treatment evaluation methodology and used the methodology to evaluate the short-term and life cycle cost-effectiveness (CE) of five rigid pavement rehabilitation treatments. Four measures of effectiveness were used in this study: the sudden decrease in surface roughness, treatment service life, increase in average pavement condition over the service life and the area bounded by the performance curve. This study established relationships that quantify the influence of pre-treatment condition on treatment effectiveness. Also, the models were developed to describe the treatment effectiveness as a function of traffic loading and climatic severity. It is seen that at high traffic loading, there is relatively little difference in treatment effectiveness across various climate severities. This study suggests that superior effectiveness of a treatment does not necessarily translate into superior CE. Also, the treatment location was found to influence the relative effectiveness of the treatments. Overall, the results suggest that treatment ‘crack-and-seat and 8-in. asphalt concrete overlay’ is the most cost-effective.     

Land Use Planning and Bushfire Risk: CFA Referrals and the February 2009 Victorian Fire Area

The Victoria Planning Provisions (VPPs) include siting and design regulations incorporated into local government planning schemes to mitigate risk in areas prone to bushfires. Introduced in 1997, these provisions were previously called the Wildfire Management Overlay (WMO). Now updated and renamed the Bushfire Management Overlay (BMO), the provision's ongoing development has been informed by fire behaviour and how houses ignite. The aim of the research reported here, conducted following the catastrophic February 2009 Victorian fires, was to review dwelling losses in terms of the WMO's effectiveness. Empirical evidence compares house losses of dwellings referred to the Country Fire Authority (CFA) via the WMO, with overall house losses. The results suggest that proportionately fewer houses referred to the CFA were lost, compared with those not assessed under the WMO. It should be noted that other factors influenced the results, such as the houses assessed under the WMO being generally newer.     

大型焦炭塔设计特点介绍

对延迟焦化装置中焦炭塔设计参数、壁厚、防腐层及裙座与壳体连接的结构形式进行介绍,重点分析裙座结构,对其优缺点进行了阐述。