Analysis and enhancement of the detection performance of the PMF-FFT acquisition algorithm for spread spectrum communication systems

针对扩频通信系统部分匹配滤波结合快速傅立叶变换(PMF-FFT)捕获算法由于FFT对频偏补偿不完全而引起相关能量衰减从而导致检测概率降低的问题,研究了检测器的输出特性,利用剩余频偏存在时检测器输出相关能量扩展的特点,提出了将相邻检测单元输出值累加作为检测变量的相邻bin联合检测方案,理论推导了该方案的虚警概率、检测概率.仿真结果表明,与原检测方案相比,该方案不仅能够提高检测概率,而且在不同剩余频偏条件下的检测具有良好的鲁棒性,适用于高动态低信噪比条件下扩频信号的快速捕获.     

基于连续潮流模型的直流配电网负荷裕度分析

直流配电网由于能灵活接纳分布式电源和直流负荷,是未来智能配电网的发展趋势。随着直流配电网中负荷需求的不断增加,系统会由于静态电压失稳而崩溃。因此,研究直流配电网的负荷裕度对保障系统安全可靠运行至关重要。该文首先建立直流配电网的潮流模型,并将含双有源桥DC-DC变换器的潮流模型嵌入到直流配电网潮流模型中,提出了基于连续潮流法的直流配电网负荷裕度计算方法。通过两类典型的拓扑结构的直流配电网仿真,结果表明直流配电网在减小网络损耗和提高供电能力方面明显优于交流配电网,而且DC-DC变换器变比增加有助于负荷裕度提升。     

家庭洗涤中织物运动测量方法探讨

家庭洗涤中织物的运动过程与洗后性能直接相关。针对洗涤运动特点,围绕织物家庭洗涤时的受力分析、动作分解、速度监测和轨迹跟踪四个方面,得出织物温态性能测量技术、高速摄像技术、传感器技术和电子示踪技术在洗涤运动测量中的研究应用;同时指出未来可以从测量设备的适用性和稳定性、织物含水率的可控性、动作分解原则的可靠性等技术难点深入探索,为实现高效、环保、智能化的家庭洗涤提供更全面的理论依据和更有效的技术支持。     

The analysis for morphological evolution and crystallography of degenerate pearlite in 100Mn13 steel

During approximate 773 K aging treatment of 100Mn13 steel, degenerate pearlite will occur and evolve into lamellar pearlite during growth process. The microstructures of degenerate pearlite and its evolutionary lamellar pearlite are observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that after 748 K, 773 K and 798 K aging, degenerate pearlites occur at grain boundary. At growth front of degenerate pearlite forming at 773 K and 798 K, pearlite presents a morphology of short lamellae of carbide and ferrite, indicating a trend of developing into lamellar pearlite. The higher the temperature is, the more obvious the trend is, and even a conventional lamellar pearlite has developed. However, there is no morphological evolution for degenerate pearlite forming at 748 K aging. Besides, the constituents of degenerate pearlite is identified as M₂₃C₆ and ferrite, and Kurdjumov-Sachs orientation relationship exists between them, (01 )_α//( 1 )_M23C6, [111]_α//[110]_M23C6. This orientation relationship maintains in morphological evolution from degenerate pearlite to lamellar pearlite.     

An adaptive Kalman filtering based State of Charge combined estimator for electric vehicle battery pack

Ah counting is not a satisfactory method for the estimation of the State of Charge (SOC) of a battery, as the initial SOC and coulombic efficiency are difficult to measure. To address this issue, a new SOC estimation method, denoted as “AEKFAh”, is proposed. This method uses the adaptive Kalman filtering method which can avoid filtering divergence resulting from uncertainty to correct for the initial value used in the Ah counting method. A Ni/MH battery test procedure, consisting of 8.08 continuous Federal Urban Driving Schedule (FUDS) cycles, is carried out to verify the method. The SOC estimation error is 2.4% when compared with the real SOC obtained from a discharge test. This compares favorably with an estimation error of 11.4% when using Ah counting.     

不同处理方法测定饲料中的三聚氰胺

采用两种不同的样品处理方法在同样的色谱条件下检测三聚氰胺含量，研究比较两种方法会对检测结果带来的影响。快速处理方法的加标回收率为84．9％～87．6％，固相萃取处理方法加标回收率为96．8％～102．0％，快速处理方法是应对突发事件测定的首选，固相萃取处理方法是定量准确测定的首选。     

论精神损害赔偿范围及其完善

论述了我国民事侵权精神损害赔偿的保护范围以及在范围上需要完善的建议。     

Mechanical properties and compression sensibility of ironstone aggregate concrete

Radiation-shielding concrete was made with ironstone aggregate. The compressive strength is affected by multi factors. The electrical conductive properties and smart performance was discovered and investigated. Experimental results show that concrete conductivity rapidly declines with increasing loading, and the conductivity is much lower than the initial value of conductive aggregate of concrete, which may be related to special characters of ironstone. This kind of concrete has widely potential applications due to its special characters and low cost. Funded by the National Natural Science Foundation of China(No. 40674060)     

A Visual Lossless Image-Recompression Framework

In this paper, we propose a novel image recompression frame?work and image quality assessment (IQA) method to efficient?ly recompress Internet images. With this framework image size is significantly re...