抗侵彻过载战斗部装药安定性实验研究

以钻地战斗部装药安定性研究为背景,在130 mm轻气炮上进行模拟装药实验,采用逆弹道实验方法;混凝土靶撞击缩比弹;PVDF传感器测试模拟装药中的应力波;结合数值计算结果初步评测缩比弹装药安定性。再采用简易平衡炮为发射载体,进行大尺寸弹丸真实装药侵彻安定性实验,证明装药安定。     

结构参数对爆炸成型弹丸性能影响的研究

为研究聚能装药结构参数对爆炸成型弹丸性能的影响,利用三维动力有限元程序,对爆炸成型弹丸形成过程进行了数值模拟,研究了装药长径比、装药密度、药型罩材料、起爆方式以及壳体厚度对爆炸成型弹丸性能的影响规律。根据研究结果,设计了一种较优化的聚能装药,并进行了聚能装药侵彻混凝土靶板实验。实验结果表明,设计的EFP聚能装药对混凝土靶板有较好的开坑效果,开坑孔径和孔深分别接近装药口径的0.6倍和6.4倍。     

自适应跳频系统抗部分频带干扰性能分析

由于部分频带干扰对跳频通信系统危害最为严重,而自适应性的引入将大大改善跳频系统的抗干扰能力。文中在常规跳频系统的基础上给出了一种自适应跳频系统,通过介绍自适应跳频系统原理,引入了双态信道模型,分析了在部分频带干扰条件下系统的误码率。在Matlab平台上对文中所给系统的性能进行仿真,并与常规跳频系统进行对比。仿真结果表明该系统能够自适应的去除干扰频点,调整跳频图案,从而使得抗干扰性能得以改善。在阻塞率为0.2时,自适应跳频系统的误码率仅为常规系统的百分之一,能够有效抵抗部分频带干扰的影响。     

The role of cesium fluoride as an n-type dopant on electron transport layer in organic light-emitting diodes

We report on the role of cesium fluoride (CsF) doping on the enhanced electron transport properties of tris-(8-hydroxyquinolin) aluminum (Alq₃) for organic light-emitting diodes. The electronic structures of CsF-doped Alq₃ layers with various doping concentration are characterized by in situ ultraviolet and X-ray photoelectron spectroscopies, showing an n-type electrical doping effect with Fermi level shift towards unoccupied molecular orbital and the formation of chemistry-induced gap-states. The increase in conductivity and reduction in electron injection barrier in CsF-doped Alq₃ layer with optimal doping concentration lead to the enhanced electron injection and transport, which are consistent with the improved electrical characteristics of OLEDs.     

光学全息图像的校正与再现识别

当印制在商品、证件和文档等物品上的光学全息图被拍摄或复制时,由于光学成像质量或拍摄条件的影响,采集的全息图像会产生畸变。据此,提出了一种全息图失真校正的方法。该方法首先运用图像处理技术,提取出所需要的全息图目标场景,然后在被提取出的全息图上确定全息图场景的边界,并在边界上自动搜索到4个顶点和4个中点的位置以及相对应的理想点的位置,最后进行投影失真校正和非线性失真校正。与其他图像畸变校正方法相比,该方法无需准备高精度标定模板,且校正和识别过程中只需用到一幅目标全息图像。实验证明,该方法能够很好地识别畸变的光学全息图,且具有效率高、快捷、识别效果好的优点。     

High‐Performance Manganese Hexacyanoferrate with Cubic Structure as Superior Cathode Material for Sodium‐Ion Batteries

Sodium manganese hexacyanoferrate (Na_xMnFe(CN)₆) is one of the most promising cathode materials for sodium‐ion batteries (SIBs) due to the high voltage and low cost. However, its cycling performance is limited by the multiple phase transitions during Na⁺ insertion/extraction. In this work, a facile strategy is developed to synthesize cubic and monoclinic structured Na_xMnFe(CN)₆, and their structure evolutions are investigated through in situ X‐ray diffraction (XRD), ex situ Raman, and X‐ray photoelectron spectroscopy (XPS) characterizations. It is revealed that the monoclinic phase undergoes undesirable multiple two‐phase reactions (monoclinic ? cubic ? tetragonal) due to the large lattice distortions caused by the Jahn–Teller effects of Mn³⁺, resulting in poor cycling performances with 38% capacity retention. The cubic Na_xMnFe(CN)₆ with high structural symmetry maintains the structural stability during the repeated Na⁺ insertion/extraction process, demonstrating impressive electrochemical performances with specific capacity of ≈120 mAh g^?1 at 3.5 V (vs Na/Na⁺), capacity retention of ≈70% over 500 cycles at 200 mA g^?1. In addition, the TiO₂//C‐MnHCF full battery is fabricated with an energy density of 111 Wh kg^?1, suggesting the great potential of cubic Na_xMnFe(CN)₆ for practical energy storage applications.     

Local community detection for multi-layer mobile network based on the trust relation

Wireless Networks - With the fast development of mobile Internet, people’s social exchange media has transformed from the traditional social network to mobile network. With the explosion of...     

业务预测与无线网话务量分析方法初探

移动用户的单机话务量是网络建设的重要依据,正确把握单机话务量的变化趋势是合理安排网络建设规模以及投资计划的基础.本文通过定性、定量相结合分析预测移动话音业务量及MOU值的发展趋势,以移动用户和MOU值预测为基础,测算移动用户的话务量以指导网络建设.     

ADSL自动测试技术及应用

建立完善的ADSL宽带接入维护测试与管理系统、提高用户服务质量已成为运营商在积极推广ADSL业务中迫切需要解决的问题。介绍了ADSL自动测试技术和典型应用。     

浅析网络和计费数据核对方法

本文阐述了网络和计费比对的分析过程,通过对比工作及时发现、处理网络和计费突发问题,保障网络设备安全运行和计费话单数据的准确.