多小区MIMO系统中干扰对齐算法分析

干扰对齐技术是解决无线通信系统中同频干扰的重要手段,与传统干扰管理方法相比可获得更大的信道复用增益,提高系统容量。基于工程应用实现的考虑,重点研究了多小区MIMO系统中干扰对齐技术的实现,对求闭式解的经典算法和分布式迭代典型算法在系统容量、收敛性等方面的性能进行了分析比较。针对未来Massive MIMO技术的应用,同时仿真分析了算法在空间相关信道下性能,并分析总结了算法的适用情况。仿真结果表明,基于矩阵投影距离的分布式迭代干扰对齐算法综合性能最优,且具有更好的工程适用性。     

基于输入子系统的Linux触摸屏驱动的实现

文中对输入子系统模型进行了介绍并重点对该驱动模型的实现原理及机制进行了分析。在此基础上,使用输入子系统驱动模型框架,以ARM处理器S3C2440嵌入式芯片为硬件平台,配合其芯片内部集成的触摸屏控制器,设计了Linux下的电阻式触摸屏驱动程序,实现了在S3C2440平台上,电阻式触摸屏的触点位置坐标采集和触点跟踪。     

脉冲频率和热输入对电弧增材制造TC4形貌和组织的影响

粗大β柱状晶导致的各项异性是电弧增材制造TC4合金面临的主要问题。为解决上述问题,采用不同的脉冲频率和热输入成形了多组试样,并结合有限元分析,重点研究了热输入和脉冲频率对成形TC4合金形貌和组织的影响。结果表明:随着脉冲频率增加,试样宽度先快速减小,随后略有增加,β晶粒由柱状晶转变为等轴晶,并且得到细化,但α相没有显著变化;提高热输入有利于获得等轴晶,但会增加试样的宽度,还会导致α相变得粗大。试样的宽度由熔池的尺寸决定,主要与平均热输入和峰值阶段输入的热量相关。提高脉冲频率能破碎树枝晶,降低温度梯度,有利于增加形核率,提高热输入也能降低温度梯度,因此能够获得等轴晶。α相形貌主要与相变时的冷却速度相关,降低热输入能增大冷却速度,细化α相。     

Testing and modelling total suction effects on compressibility and creep of crushable granular material

Recent works have shown that delayed events of particle crushing are partially responsible of creep deformation in granular materials, and that Stress Corrosion Cracking promoted by high humidity within particles is the source of this mechanism. A number of experimental studies have focused on creep behaviour of water saturated samples and wetting-deformation after soaking dry material. However, there are few evidences of the effect of varying total suction in time-dependent deformation of partially saturated crushable material, and this mechanism have been rarely considered in constitutive models. The aims of this paper are to present experimental evidence of the effect of total suction on compressibility and creep of sandy sized samples from crushed rock, and to propose a simple one-dimensional elasto-plastic modelling approach based on the enhancement of an existing model. Oedometric compression tests at different total suctions are presented. The results show that compressibility and creep strains increase with both stress and humidity. The model proposed uses a time-dependent hardening law coupling suction with the amount of particle breakage. Based on preliminary calibrations, the model captures the effect of suction and time-dependent behaviour over a large range of total suction.     

土力学的新概念与特殊土强度初探

讨论了红粘土的实际饱和度的算法;分析了蒙脱石颗粒内表面结合水对膨胀土的三项组成的影响,提出了膨胀土实际饱和度和孔隙比的算法;认为湿陷性黄土由土骨架(包括微小孔隙)和大孔隙组成,提出了骨架率、骨架饱和度和骨架孔隙比的算法。进一步,求得特殊土的饱和度系数和自由水通道率。再进一步,得到特殊土进行大气张力系列的地基承载力、库伦抗剪强度、郎肯土压力、库伦土压力、土坡稳定计算的方法。新概念土力学以有效应力的新概念为基础,以抗剪极限状态的有效应力的大气张力公式为基本公式。     

基于孔结构参数的混凝土气体扩散模型

提出了一种反映混凝土孔结构特征的毛细管束几何模型,并运用分形维数表征了孔数目、孔隙率和曲折度等参数.通过水饱和度与气体有效扩散空间的关系,建立了考虑水饱和度影响的混凝土气体扩散模型,并运用该模型分析了水饱和度、水灰比和环境温度等对气体扩散系数的影响.结果表明:水饱和度是影响混凝土中气体扩散性能的一个主要参数,当水饱和度达到85%(质量分数)时,对气体扩散系数的影响最为显著.     

高精度碳氧比测井在泌阳凹陷的应用

为满足河南油田泌阳凹陷老区特高含水期非均质油层剩余油挖潜的需要,采用国产高精度碳氧比测井仪,其双源距设计减小了井眼和水泥环等因素的影响。通过对其响应特征分析,开展了影响因素校正,应用其测井参数建立了地层参数解释模型。该仪器采集的全硅计数率能较好地反映地层岩性,可用于地层对比和泥质含量计算;俘获与非弹计数比反映地层孔隙性,可用于孔隙度计算;采用碳氧比与孔隙度交会法、碳氧比和硅钙比幅度差与含油饱和度交会法、可计算储层含油饱和度。根据17口井的投产结果,建立了区域储层评价的定量标准,满足了储层饱和度评价的需要。     

Research on orbital angular momentum communication technology

As the good orthogonality between the different modes of orbital angular momentum (OAM),the application of OAM technology in wireless communication has gained increasing popularity in recent years with great potential for capacity improvement.OAM-based wireless communication technology can effectively improve spectrum utilization,but also brings some challenges.Firstly,the research status and progress of OAM technology in the field of wireless communication were introduced and the relationship between OAM and MIMO technology was compared and analyzed combined with the basic principle of OAM.Moreover,the dispute “Does OAM provides a new dimension?” was concluded.Then,the generation and reception methods of OAM were summarized.The key techniques and application fields were overviewed.Finally,the challenges of the technology in practical application were analyzed and the future development trends and follow-up research directions were point out,which would provide a reference and help for the research in this field.