基于倏逝波的光纤生物传感器研究

构建了一种以光纤束作为激发光信号和荧光信号传输通道的光纤生物传感器结构.根据光纤探针的倏逝波理论和模式匹配理论对光纤探针的几何形状进行了设计,制作了数组光纤探针并根据需要对其中一部分进行荧光标记.选择了光纤探针置于空气中和水溶液中两种情况,对光纤传感器系统进行了信号检测实验,对比标记了的和未标记的相同几何结构参数的光纤探针两者在系统中被探测的信号差异.从二者的差别区分出系统所探测的倏逝波激发的荧光信号,证明了该光纤传感器系统的可行性.     

Investigation of formation mechanism of Ti3SiC2 by high pressure and high-temperature synthesis

ABSTRACT

In this paper, synthesis of titanium silicon carbide (Ti₃SiC₂) under high pressure and high-temperature condition has been investigated by using the reactant systems Ti/Si/C, Ti/SiC/TiC, Ti/SiC/C and Ti/TiC/Si. Results reveal that Ti/TiC/Si is unsuited to the synthesis of Ti₃SiC₂ under a high pressure of 2.0?GPa, while an elemental mixture of Ti/Si/C is applicable. By the addition of Al, Ti₃SiC₂ with 95.8?wt% purity was obtained from elemental mixture with a large excess of silicon. The optimum experimental parameters were determined as Ti/Si/Al/C having the molar ratio of 3:1.5:0.5:1.9, holding at 2.0?GPa and 1300?°C for 60?min.     

压缩采样中模拟信息转换器的性能仿真

受奈李斯特采样定理的约束,传统通信设备在提高分辨率和满足实时性要求时,面临高采样率、快处理速度等问题的挑战.而根据压缩采样(Compressive Sensing,CS)理论构建的模拟信息转换器(Analog to Information Converter,AIC)只需进行远低于奈奎斯特采样率采样信号,即可实现对原信...     

Location based routing addressing mechanism of integrated satellite and terrestrial network

The ever-changing characteristics of the connection between the satellite network and the terrestrial network caused by the high-speed movement of the satellites have always been one of the most important problem that plagues the routing mechanism of the satellite network and integrated network.To address this problem,a location addressing based routing mechanism of integrated satellite and terrestrial network (LA-ISTN) was proposed.LA-ISTN exploited the user’s physical location in the user’s IP address to calculate the routing orientation.Based on the orientation,LA-ISTN could choose the best forward interface.Theoretical analysis and simulation experiments show that compared with snapshot protocol and OSPF routing protocol,LA-ISTN significantly reduces the route table storage overhead,with no routing updates cost caused by neighbor packet switching and communication.Inter-satellite route selection is not dependent on the prediction of link connection relations,with strong robustness,can always guarantee the network’s availability.     

基于路灯杆基站的规划建模研究

对路灯杆基站的应用场合原则、选址模型、天馈系统规划设计进行了详细的说明,并通过应用案例证明了关于路灯杆基站的规划设计方法在打造联通精品网络的工作中有着深远的推广意义。     

负荷跟踪发电系统自适应控制方法

随着智能电网的建设,电力系统要求发电机组既能快速响应负荷变化,又能保证自身安全经济地运行。发电系统中锅炉蒸汽温度控制过程的动态特性随负荷的大小而变化,并且存在控制量和操作量产生相互干扰等问题。文中提出了一种能够进行负荷跟踪的模型参考自适应控制系统,并利用梯度法推导出可以快速调节误差的参量调整机构,以确保系统的稳定性和抗干扰性。并进行了数据仿真,其仿真结果表明,采用模型参考自适应控制系统能够得到动态性能参数和控制效果,具有一定的理论指导意义和应用前景。     

A random sequence generator based on chaotic circuits

In this paper, a random sequence generator based on chaotic circuits is presented. Fundamental principle and experimental circuit have been carried out in case of Chua's circuit. The statistical results are in good agreement with probability characteristics of random sequence.     

S波段圆波导缝隙全向天线的设计

设计了一种S波段圆波导缝隙全向天线,该天线是在圆波导柱面上开凿一定数量的纵列缝,组成缝隙阵列。经过仿真优化设计和测试,天线在360°方位面范围内幅度起伏小,具有很好的全向特性,目前天线已成功地应用到了雷达产品中。     

基于瑞利散射的单端BOTDA系统温度特性研究

提出一种不受电光调制器传输曲线温度漂移现象影响的基于瑞利散射的单端布里渊光时域分析系统,并对系统所需的合成信号及温度特性进行分析,通过搭建单端布里渊光时域分析温度传感系统测量系统的温度特性.结果表明:通过测量布里渊增益谱获得的布里渊频移与温度呈良好的线性关系;由单端布里渊光时域分析温度测量系统获得的布里渊频移的温度系数为1.109 MHz/℃,与传统双端布里渊光时域分析系统获得的1.20 MHz/℃具有良好的一致性,在1.77 km光纤上可实现9.5m空间分辨率的温度传感测量.     

High Optical Gain of Solution-Processed Mixed-Cation CsPbBr3 Thin Films towards Enhanced Amplified Spontaneous Emission

A solution-processed thin film made of all-inorganic CsPbBr₃ perovskite is a promising candidate for low-cost and flexible green-color lasers. However, the amplified spontaneous emission (ASE) of solution-processed CsPbBr₃ films still experiences a high threshold owing to poor morphology and insufficient optical gain. Here, a multiple-cation doping strategy is demonstrated to develop compact, smooth thin films of Cs_0.87(FAMA)_0.13PbBr₃/(NMA)₂PbBr₄ (FA: formamidinium; MA: methylammonium; NMA: naphthylmethylammonium) with a record high net modal optical gain of ≈ 3030 cm⁻¹ and low propagation loss of 1.0 cm⁻¹. The FA and MA cations improve the crystallization kinetics to form continuous films, and the NMA cations reduce the grain dimension, increase film dispersibility/uniformity, and enhance spatial confinement to promote optical gain. Room-temperature ASE is demonstrated under a low threshold of ≈ 3.8  µ J cm⁻² without degradation after four months of storage in glove box or excitation by 3 × 10⁷ laser pulses. These findings provide insights into enhancing the optical gain and lowering the threshold of perovskite lasers in terms of molecular synthesis and microstructure engineering.