基于倾角导向梯度能量熵的断层检测方法

断层解释是三维地震数据精细构造解释的关键。三维不连续性地震几何属性分析技术的发展,为断层等不连续性地质边界的检测和识别提供了极大的便利。针对传统地震几何属性对随机噪声较为敏感,用于检测和识别微小断层效果不好这一现实问题,提出了一种基于倾角导向梯度能量熵的相干分析方法。首先利用梯度结构张量获取倾角信息,然后通过构建梯度相关矩阵计算局部地震数据的梯度能量熵值。高能量熵值代表数据的连续性很差,低能量熵值代表数据的连续性很好,因此可以利用能量熵值刻画三维地震数据的不连续性空间结构信息。理论模型和实际数据测试表明,新方法不仅抗噪能力较强,而且对断层等不连续性边界的检测效果比超级地震道第一代相干体（ST-C1）、超级地震道第三代相干体（ST-C3）和局部结构熵相干体（LSE）都好,可以有效地用于三维断层及其他地质边界的地震解释。     

数字射频存储器在脉冲多普勒雷达噪声干扰中的应用

采用数字射频存储器(DRFM)技术的噪声干扰机,具有瞄频精度高、噪声带宽窄、干扰功率利用率高的特点,可对脉冲多普勒(PD)雷达实施有效干扰。介绍了DRFM干扰机的组成和工作原理。并分析了瞄频误差和寄生信号的产生以及它们对干扰噪声的影响。     

Thermal effects on structure and photoluminescence properties of diamond-like carbon films prepared by pulsed laser deposition

With their unique properties such as high hardness ,lowfriction,chemical inertness and optical transparency,Diamond-like carbon(DLC) fil ms are usedina wide ar-ea of industrial applications ,as a protective coating insuch areas as optical windows ,magneti…     

基于微功率无线通信技术的电冰箱能效试验系统的设计（上）

传统的电冰箱能效试验采用的热电偶连接线必须跨越冰箱门才能连接到温度记录仪上,这样必定在冰箱门处产生细小的缝隙,从而影响了间室的密封性,使检测的结果出现误差。该文介绍了一种利用微功率无线通信技术开发的新型检测系统,避免了此类误差的产生,并阐述了该系统的工作原理和软硬件结构。实际应用证明,该系统各方面性能良好,测量数据准确...     

目标机动导致导弹脱靶判别建模与仿真

针对目标机动能否逃脱导弹攻击的判断问题,根据比例导引法弹目相对运动方程组分析了目标机动逃脱导弹攻击的条件,推导了目标法向过载与导弹最大需用过载间的关系,建立了目标机动导致比例导引导弹脱靶判别的数学模型,运用该模型对算例进行了仿真与分析,仿真结果符合机动逃脱的运动学一般规律,说明该模型可以用于对抗仿真系统中飞机能否机动逃脱的判据。     

Multiuser Frequency Synchronization for Interleaved-OFDMA Uplink Systems

This paper investigates the frequency synchronization in the uplink of the Orthogonal frequency- division multiple access （OFDMA） system with interleaved subcarrier assignment. In such a system, one of the key problems is the multiuser frequency synchronization, which focuses on the multiple-parameter estimation of the Carrier frequency offsets （CFOs）. In this paper, we propose a two-stage frequency offset estimation algorithm. The main advantage of the proposed method is that it can obtain the CFOs of all users simultaneously using only one OFDMA block. In addition, a novel CFO-compensation method is presented. Based on the inner signal structure of interleaved-OFDMA uplink, the new scheme uses adaptive beamformer to compensate the CFO of each user and isolate the signals of all users at the same time. Compared to the previously known methods, the proposed algorithm can provide accurate frequency synchronization and data detection without feeding CFO estimates back to active users for frequency adjustment.     

Multi-Fidelity High-Throughput Optimization of Electrical Conductivity in P3HT-CNT Composites

Combining high-throughput experiments with machine learning accelerates materials and process optimization toward user-specified target properties. In this study, a rapid machine learning-driven automated flow mixing setup with a high-throughput drop-casting system is introduced for thin film preparation, followed by fast characterization of proxy optical and target electrical properties that completes one cycle of learning with 160 unique samples in a single day, a > 10 ×  improvement relative to quantified, manual-controlled baseline. Regio-regular poly-3-hexylthiophene is combined with various types of carbon nanotubes, to identify the optimum composition and synthesis conditions to realize electrical conductivities as high as state-of-the-art 1000 S cm⁻¹. The results are subsequently verified and explained using offline high-fidelity experiments. Graph-based model selection strategies with classical regression that optimize among multi-fidelity noisy input-output measurements are introduced. These strategies present a robust machine-learning driven high-throughput experimental scheme that can be effectively applied to understand, optimize, and design new materials and composites.     

一种空管S波段30 kW固态发射机的设计

介绍了一种S波段30 kW空管雷达固态发射机的性能指标,阐述了发射机射频链路、监控保护、电源和冷却各部分的设计特点和实现方法;其次,针对空管雷达发射机的特殊需求,描述了在线更换技术和数字化检测技术;最后给出了发射机性能测试结果.本发射机的成功研制,可为今后其他固态发射机设计提供参考.     

Fully Printed Dual‐Band Power Divider Miniaturized by CRLH Phase‐Shift Lines

In this letter, a compact and fully printed composite right‐ and left‐handed (CRLH) dual‐band power divider is proposed. The branches of the conventional Wilkinson power divider are replaced by subwavelength CRLH phase‐shift lines having +90° for one frequency and ?90° for another frequency for dual‐band and miniaturization performance. Equations are derived for the even‐ and odd‐mode analysis combined with the dual‐band CRLH circuit. A PCS and a WLAN band are chosen as the test case and the circuit approach agrees with the CAD simulation and the measurement. Additionally, the CRLH property is shown with the dispersion diagram and the eightfold size reduction is noted.     

一种高可靠GNSS接收机位同步算法

位同步技术是GNSS接收机技术的重要组成部分,位同步错误会导致接收机伪距解算错误及无法正确解调电文。针对弹载GNSS接收机的高可靠性要求,提出了一种高可靠GNSS接收机位同步算法,对最大似然位同步算法进行了改进。在非相干积分过程中等间隔提取中间结果进行观测,综合多次观测结果和最终非相干积分结果进行位同步判断。数值仿真与分析表明,在弱信号情况下,在不增加估计时间的前提下,可以大幅度减小错误同步概率,对于提高弹载GNSS接收机可靠性有着重要意义。