合成孔径雷达的有源欺骗干扰方法研究

本文根据SAR成像原理和地面回波信号模型,提出了对SAR进行有源欺骗干扰的方法.文中详细地讨论了有源干扰的基本原理,分析了干扰信号模型,并用实际SAR数据进行了仿真实验,欺骗图像成功加到了真实SAR图像中.     

光纤光栅应变传感系统在船舶结构监测中的应用

介绍了一种光纤光栅应变传感系统在船舶结构监测中的应用.首先设计了贴片式的光纤光栅应变传感器,采用无胶化封装,具有良好的线性和重复性.然后搭建了基于非平衡M-Z干涉仪的PGC解调系统,实现了船体应变信号的高精度实时解调.最后介绍了传感器的施工工艺和流程,并对传感系统采集到的结构应变数据进行了分析.研究成果对光纤光栅应变传感系统在船舶结构监测中的推广应用具有工程指导意义.     

Bioavailability Enhancement of Cepharanthine via Pulmonary Administration in Rats and Its Therapeutic Potential for Pulmonary Fibrosis Associated with COVID-19 Infection

Cepharanthine (CEP) has excellent anti-SARS-CoV-2 properties, indicating its favorable potential for COVID-19 treatment. However, its application is challenged by its poor dissolubility and oral bioavailability. The present study aimed to improve the bioavailability of CEP by optimizing its solubility and through a pulmonary delivery method, which improved its bioavailability by five times when compared to that through the oral delivery method (68.07% vs. 13.15%). An ultra-performance liquid chromatography tandem-mass spectrometry (UPLC-MS/MS) method for quantification of CEP in rat plasma was developed and validated to support the bioavailability and pharmacokinetic studies. In addition, pulmonary fibrosis was recognized as a sequela of COVID-19 infection, warranting further evaluation of the therapeutic potential of CEP on a rat lung fibrosis model. The antifibrotic effect was assessed by analysis of lung index and histopathological examination, detection of transforming growth factor (TGF)-β1, interleukin-6 (IL-6), α-smooth muscle actin (α-SMA), and hydroxyproline level in serum or lung tissues. Our data demonstrated that CEP could significantly alleviate bleomycin (BLM)-induced collagen accumulation and inflammation, thereby exerting protective effects against pulmonary fibrosis. Our results provide evidence supporting the hypothesis that pulmonary delivery CEP may be a promising therapy for pulmonary fibrosis associated with COVID-19 infection.     

基于声表面波技术的飞机结冰预警系统研究

飞机结冰严重影响飞行安全,现有结冰传感器都只在飞机结冰后才进行告警。利用声表面波结冰传感器及声表面波温度传感器设计了飞机结冰预先告警系统。研究了声表面波结冰传感器的原理,并设计了传感器信号的告警逻辑关系,通过等效电路对无线声表面波冰传感器进行仿真。仿真结果表明,声表面波飞机结冰预警系统可用以降低结冰信号的虚警率。     

Room-Temperature Magnetism Realized by Doping Fe into Ferroelectric LiTaO3

We synthesize LiTal-x FexO3-σ （LTFO） remain single phase up to x = 0.09 ceramics by the conventional solid-state reaction method. The samples The magnetic measurements show that the doping of Fe successfully realizes ferromagnetism of LTFO at room temperature. The dielectric measurements indicate that LTFO is ferroelectric, similarly to LiTaO3 （LTO）, but its ferroelectric Curie temperature seems to decrease with the increasing Fe content. By means of doping Fe ions into LTO, the coexistence of spontaneous electric polarization and spontaneous magnetic moment is realized at room temperature.     

光衍射法研究水表面波的性质

将水的表面波视作一种正弦相位型光栅,导出了水表面波衍射光斑间距与其波长的关系,从而利用水表面波对激光的衍射测定了水波波长,确定了表面波成分,即在所用实验频率范围内毛细波占主导地位,验证了表面波的色散关系.     

菠菜和苏州青类囊体溶液的光谱特性

通过分析不同波长光激发下菠菜(Spinach)和苏州青(Suzhou Green)类囊体溶液的发射光谱和荧光光谱,以及同一波长下磁场处理前后类囊体溶液的光谱变化,探讨了低强度稳恒磁场对类囊体溶液的作用机理.结果表明,类囊体溶液中形成了大量的氢键,磁场处理前菠菜和苏州青的氢键喇曼散射峰为531 nm和533.2 nm,两者光系统II(PSII)荧光分别在689.8 nm和686 nm;磁场处理后两者的喇曼散射峰变为532.8 nm和532.4 nm,PSII荧光变为686.8 nm和685.4 nm.磁场改变了两样品中氢键键能,使其趋于相等.     

ICP—AES法中稀土元素间的相互干扰研究

稀土元素的谱线较复杂,相互间存在着不同程度的干扰。本文着重研究了ＩＣＰ－ＡＥＳ法中,它们间的干扰情况,并用几种校正方法进行了比较。     

激光激发水中产生超声波的实验研究

采用压电陶瓷水听器研究了Nd：YAG脉冲激光激发水中产生瞬态超声波的特性,给出了声压信号随距离的变化关系。研究结果表明：用激光产生水下声波是完全可行的。当观测点与光击穿区的距离r远大于柱体长度时,垂直于光传播方向的激光瞬态超声波幅值与r成反比;当观测点与光击穿区的距离r很小时,垂直于光传播方向的声压幅值与产成反比。此外,当激光入射角度发生变化,超声脉冲的幅值也随之发生变化,其幅值在激光束垂直入射的时候最大。     

偏振无关光纤迈克耳孙干涉型磁场传感器研究

采用琼斯矩阵法分析了法拉第旋转镜消除偏振诱导信号衰落的原理,阐述了基于磁致伸缩的光纤迈克耳孙干涉型磁场传感器基本原理。利用闭环控制工作点的方法,稳定了磁场传感器系统的工作点,然后对该系统进行了检测。结果表明,磁场传感器系统具有良好的稳定性,当外界磁场较小时,输出与外界磁场大小呈线性关系,在幅度为4000nT的交流磁场调制下,相位灵敏度可达1．4×10-3rad／nT,最小可测磁场达0．57nT。