Recovering Sociology from the Trash Heap: Of Waste Politics and the Spatialization of Local Representation in Lagos

This article excavates the debate that unfolded during the 1980s between Jacques Rancière and Pierre Bourdieu to shed light on the theoretical divide that still cuts across the field of urban studies today. Looking at contemporary Rancièrian scholarship through a Bourdieusian lens, it points to their main theoretical shortcomings and reasserts the value of relational, field‐based and empirically grounded approaches to urban politics. At the same time, this article engages seriously Rancière's critique of Bourdieu's failure to account for space in order to question the territoriality inherent to the notion of field. We put this theoretical discussion to the test of Lagos's garbage. Drawing on an ethnographic study conducted in Lagos from 2015 to 2016, we propose analyzing the process of spatialization of the field of local representation by looking at the ways solid waste—here conceived as a political opportunity—is mobilized by different actors. We argue that the deployment of a waste infrastructure in Lagos is congruent with a relative disinvestment in practices of territorial control that reshapes the structure of local representation, reconfiguring the ‘stage’ on which politics is played out in the Nigerian metropolis.     

利用相位差变化趋势的多源信号关联

针对多源信号关联难度大、关联准确率低的问题，利用同一目标平台上搭载的多个辐射源信号具有一致的动态变化趋势这一特点，提出一种利用相位差特征的多源信号关联方法。已知阵列形式和侦测点位置，通过对侦收到的多个辐射源信号进行处理，获取相位差信息并累积形成相位差变化趋势；对比提取疑似相似段，根据相似性判决策略进行有效关联。该方法能有效避免不同传感器对位置测量的误差影响，相比传统基于位置信息关联的方法，能有效提升关联准确率。仿真和实测数据分析证明了该方法的有效性，在阵列形式和侦测点位置已知的条件下该方法具有重要工程意义。     

Municipal solid waste management and greenhouse gas emissions at international airports: A case study of Astana International Airport

The steady expansion of the city of Astana and the increase of airport capacity is leading to an increase in municipal solid waste generation. The purpose of this study was to perform compositional analysis of the municipal solid waste produced at the Astana International Airport and evaluate different waste management scenarios in terms of greenhouse gas emissions. Recyclable and combustible fractions were found to be the major fractions (over 50%) of the total municipal solid waste generated in the Astana International Airport. Four base greenhouse gas emissions scenarios were proposed in this study, namely scenario-1 describing the current municipal solid waste management case, scenario-2 with integration of 29% recycling and 71% of municipal solid waste landfilling, scenario-3 for 100% of airport municipal solid waste being incinerated and scenario-4 for recycling 29% and the remaining waste being processed for energy recovery purposes. The proposed scenario 2 demonstrated significantly reduced net greenhouse gas emissions (t CO₂ eq/year) over the existing scenario 1, while scenarios 3 and 4 showed negative net greenhouse gas emissions. The experimental data provided and the scenarios discussed in this work are useful tools for decision makers for environmental waste management at airports.     

基于软件无线电平台的1090ES扩容信号收发处理

随着空中交通的信息传输与新应用拓展需求不断增加，1090ES信号容量有限问题日益显现，对1090ES信号进行容量扩充是一种有效解决途径。针对一种基于脉内调相的1090ES信号扩容技术，给出了叠加调制的信号模型，研究了1090ES信号的解调解码算法；在GNU Radio+ USRP软件无线电平台上，实现了1090ES扩容信号的产生和接收处理，包括脉冲位置调制（Pulse Position Modulation，PPM）与8PSK叠加调制、低通滤波、报头检测、载波同步、PPM解码和相位解调等，并利用Matlab对实验的解码错误率和信号的频谱特性做了统计分析与仿真，结果表明了该扩容技术的可行性。     

一种适用于遥测测距信号的新型码跟踪环

遥测测距技术采用再生伪码作为上行链路信号。针对飞行器现有码跟踪环结构复杂、低信噪比条件下环路跟踪性能差的问题，提出了一种新的基于锁相环的码跟踪环结构，推导了环路的信号处理流程。该结构降低了环路实现的复杂度，改善了低信噪比条件下的相位测量精度，仿真进一步验证了方法的有效性和稳定性，较现有方法在信噪比为-10 dB时能提高1.5×10－3个码片的精度，适合遥测测距技术。     

相关信噪比对天线组阵相位估计性能的影响

传统天线组阵理论为了简化分析，均假设反正切相位鉴别器是一种最大似然估计器，其估计方差能够达到克拉美-罗下界。然而当相关信噪比在中等值以下时，这一假设条件不再适用。为此，分析了相关信噪比对相位估计性能的影响。针对传统天线组阵合成性能分析方法在描述低相关信噪比条件下相位估计性能方面存在的问题，通过引入修正因子，得到了相位估计方差的理论公式，实现了对低相关信噪比条件下相位估计性能的准确描述。     

一种针对压缩域信号的新型锁相环技术

针对通信信号压缩采样获得的压缩域信号频率、相位提取问题,提出了一种基于压缩感知的新型锁相环技术。通过深入研究压缩域的信号估计问题,提出了压缩域锁相环路,可以直接在压缩域同步跟踪信号频率和相位变化,不再需要高复杂度的信号重构处理。分析了环路模型及其估计性能,并针对该锁相环可行性和性能分别进行了仿真实验。仿真结果不仅验证了压缩域锁相环的可行性,同时表明该环路能够实现高动态信号的高精度频率提取。压缩域锁相环的应用潜力较大,例如可以作为压缩感知通信接收机的同步解调方法。     

单光子卫星量子通信噪声和干扰分析

卫星量子通信是建立全球量子通信网络的最佳选择之一。针对采用偏振编码的卫星量子通信中的偏振保持问题,研究了大气散射和卫星与地面站间相对运动等因素对量子偏振态相位和对准的影响以及相位延迟和对准误差对系统量子误码率的影响,分析了背景噪声和系统硬件噪声对通信产生的影响以及单光子通信过程中可能受到的光子分离攻击干扰,为量子信号认知设计提供借鉴意义。     

设计优化在建设项目成本中的应用分析

建设项目成本控制的重点阶段是建设项目的设计阶段,结合实际工程经验,本文将会通过对建设项目设计阶段如何有效控制成本进行详细的阐述,分析与探究成本控制有何实际意义,并提供一定参考性的建设意见。     

反相高效液相色谱法快速分析紫脲酸

为了给咖啡因生产中的亚硝化反应、还原工艺提供准确的中间体检测数据,寻找紫脲酸含量快速分析方法,利用反相高效液相色谱法,通过进行紫脲酸样品波长选择实验、系统适用性实验、定量摸索实验、精密度实验、线性实验,确定了检测波长和紫脲酸样品质量浓度与样品峰面积之间的线性关系。在15.80~188.60mg/L范围内,紫脲酸样品质量浓度与样品峰面积之间的线性方程为y=71.785x,相关系数R2=0.999 8,表明紫脲酸样品质量浓度与样品峰面积之间具有良好的线性关系。使用反相高效液相色谱法能准确、快速检测紫脲酸样品含量,及时对还原反应进行过程监控。