开缝腔体谐振特性放大了进入腔内的耦合能量,对内部电子设备构成严重威胁.文中建立内含金属隔板、吸波体等负载的圆柱腔体模型,提出了在隔板上涂覆吸波材料以抑制谐振的新方式,研究了吸波体电磁特性对谐振的影响.结果表明:隔板越靠近腔体前壁放置、板间距越大,对内部场影响越小,谐振点出现位置越接近空腔固有模式;谐振点处屏蔽效能(Shielding Efficiency,SE)的提升是隔板和吸波材料综合作用的结果,隔板可迫使谐振点迁移,吸波材料能改善谐振特性,并且涂覆磁性吸波材料性能更优;在隔板双面涂敷吸波材料抑制高次谐振效果更好;适当增加隔板上涂覆材料厚度或提高材料相对磁导率,都能实现和全腔内壁涂覆相同的谐振抑制效果,效费比也更高;场强分布因传播模式不同而不同,强电场区应放置电性吸波体才有效.

实际金属腔体常开有多个通道,使得腔内电磁环境变得复杂.以分析腔体多通道耦合电磁特性为出发点,建立平面波入射下矩形、圆柱腔体实例模型,引入对比系数作为评价手段,侧重研究孔缝、贯穿线缆两种耦合通道对腔内电磁场的影响,寻求共性规律.结果 表明:腔外线缆长度变化不影响谐振点出现位置,随长度增加腔体屏蔽效能(SE)下降;腔内线缆随长度增加,谐振频率降低,两腔体具有如上共性结论.基于给定的模型及参数设定,通过比较系数可判断矩形腔体450 MHz之前线缆耦合为主;贯穿线较长时,510 MHz之前圆柱腔体线缆耦合为主;贯穿线较短时,两个局部频点之外的其它频段孔缝耦合为主;涂覆磁损耗型吸波材料提升腔体SE效果最好,且SE越低,提升效果越明显.

The classical restoration algorithm can not effectively recover the full frequency domain information of the object, which leads to the serious optical sidelobes. In this paper, the application of metal nano arrays in structured light illumination is studied, and the problem of optical sidelobes in plasmonic structured illumination microscopy is solved using Maximum A Posteriori (MAP) estimation. The research shows that the MAP estimation method can effectively restore the high spatial frequency information, and through the reasonable selection of optimization parameters to achieve the purpose of suppressing optical sidelobes. At the wavelength of 520 nm, 1.3 numerical aperture, the lateral resolution can be obtained at FWHM of 65 nm, which is about 3.6 times of the traditional fluorescence microscope. This technology has potential application application in the field of life science.

开缝屏蔽腔体不能完全阻断能量耦合,导致在腔内局部区域、特定频点附近形成场强增强效应,对敏感器件或线路构成威胁.以分析腔内场强增强效应及研究抑制方法为出发点,建立3种开缝腔体数值模型,提出并验证腔体涂覆吸波材料、内置吸波柱、内置双层PCB板等谐振抑制方法的有效性.结果表明:在3种腔体模型内表面涂覆吸波材料均能有效抑制场强增强效应,并且涂覆磁损耗型吸波材料效果最好;随着涂覆厚度的增加,谐振抑制效果也增强;腔体中心放置吸波柱,应使用电损耗型吸波材料.腔体内置PCB板既能实现对电子器件和线路的承载功能,还可整体大幅度提升腔体屏蔽效能,对谐振效应的抑制体现在迫使腔体主谐振点偏移,结合使用吸波材料,高阶第2谐振点处谐振抑制效果也明显改善.

A beam expanding focusing lens of single scanning laser vibrometer is analyzed and designed by ZEMAX. Firstly, the Gauss He-Ne laser source is simulated, and then the initial structure of the system is calculated. The relationship between the moving distance of the front lens and the laser focusing distance is analyzed, and the spot sizes at different focusing distances are obtained. Finally, the mechanical structure of the adjustable focusing system is designed. The adjustment of the structure is smooth, and the front lens can not rotate. Thereby the errors caused by rotating lens are reduced.

The external energy that enters the slotted cavity through the penetrative wire will generate the induction current on the MSL.The coupling damage to sensitive device is increased.The model of the shield cavity with penetrative wire and PCB are established.The coupling calculations are carried out by multi angles.After validating the model validity,the corresponding current variation law due to the parameter variations such as the different PCB models,the different termination resistances,the wire radius,the connection between the wire and the cavity wall and the multi wires are discussed by the finite element method.The results show:the effect for field of the double medium model is closer to the actual PCB structure;the impedance matching with MSL can't be considered under the condition of little resistance difference,the resistance may not be equal.The current will increase when the wire radius becomes large.The current when the wire is connected with the different cavity surface are much higher than non contact situation,and they will inspire the new resonance points.The current of the multi wires is higher than the single case,it has the same effect when the line spacing changes.It is more obvious especially before the first resonance;The resonance position will not be affected by multi wires.

The current produced by the coupling between the MSL and the external electromagnetic energy will cause damage to sensitive devices.But the research is not enough at present.The PCB board with a corner MSL in the slot shelled is built as the research object.Using current as the main entry point,the multi parameter coupling is calculated.First,the corresponding model is established and validated.The plane wave excitation is used to investigate the influence for current.The Parameters include the different positions,whether there is a shielding cavity,the MSL angle size and the corner compensation.The results show:the currents of the different positions have little effect for the straight MSL.The value of straight MSL is greater than the one of bend MSL,and the difference decreases with the increasing frequency.At the resonance point,the suppression effect of the cavity is weakened or even completely ineffective;When MSL and E are placed in parallel,it can be arranged into short trace,When MSL and E is placed vertically,it can be arranged into long trace.With the increase of MSL width,the current will increase,but the trend will slow down.The corner compensation is effective for improving SI,but it is limited for the electromagnetic coupling.The resonant point position is not affected due to the multi parameters variation is the common result.

因孔缝的存在屏蔽腔防护性能在谐振点处被大幅度弱化,现有文献多单以屏蔽效能(SE)作为测算点,对于电磁能量与PCB上MSL耦合而产生感应电流(Current)的计算没有给予足够关注.有鉴于此,建立内置带MSL的PCB开缝壳体等效计算模型,在模型有效性验证后,使用有限元法研究平面波激励下,MSL端接负载、孔缝尺寸、PCB尺寸及位置等参数变化对SE和Current的影响.结果表明:Current和SE虽然幅值变化不同,但曲线走势具有一定的对称性,尤其是谐振频点处;负载取值不同对结果没有影响;孔缝长宽尺寸变化对第二谐振有明显影响,取值增大频点左移是共性,且受长度影响更明显;PCB长宽尺寸增加,第一谐振左移是共性,且频移幅度受宽度影响更大,PCB宽度越大,第二谐振被激发出的可能性也变大;PCB等值靠近左壁,第一谐振等频右移,第二谐振等频左移.

非平行微带线作为电路板上常见的电气连接方式,因夹角的存在导致线间耦合复杂且很难预测,一直未被给予足够的关注.基于此情况,建立非平行微带线耦合模型,在验证模型有效性的基础上,使用有限元法(FEM)详细研究由平行到非平行转变导致的串扰曲线演变过程.验证使用防护带及宽度变化对非平行微带线间串扰抑制的有效性.为保证衰减效果和节约制板费用,提出使用短防护带进行串扰抑制,同时研究短防护带起始位置对抑制效果的影响.考察串扰对接地孔半径变化时的依赖性,通过计算得到了与已有文献不同的结论.通过对这些关系的详细分析进而总结相应的规律,为非平行微带线及防护带的优化设计提供理论指导.

为满足生物医学领域对传感器灵敏度和特异性的要求,利用金纳米棒对纳米光纤消逝场强的消光作用,提出基于金纳米棒标记放大的锥形光纤生化传感器.通过理论计算金纳米棒对光纤传输特性的影响,设计实验证明纳米光纤具有对单个金纳米棒的响应能力.采用双抗夹心法对PBS溶液中的羊IgG检测,检测下限可达0.02 ng/mL,证实此种传感器具有极高的灵敏度和特异性.提出的纳米光纤生化传感器结构简单、响应迅速、成本低廉,在医学临床诊断、食品安全检测、环境监测领域具有重要的实用价值.

Taking advantage of the centrifugal microfluidic chip for biochemical analysis, an optical detection system based on absorbance detection technology is designed. The effect of the poor light output stability of xenon flash lamp on test results is reduced by dual wavelength detection. The chip is located precisely by synchronous trigger positioning in the detection process. The effect of sampling error on the test results is also analyzed. The test results show that the absorbance repeatability of the system is 0.0994% by dual wavelength detection; the locating error is extremely small, it is 0.1429% by synchronous trigger positioning; and the sampling error is lower than 2%, which meets the requirements of national standards. The system has the advantages of simple structure, easy integration, and stable and reliable test results, it is promising in medical diagnosis.

为降低飞轮电控系统对其他星载电子设备的电磁干扰,以PWM全桥电路共模辐射源为研究对象,重点分析由开关管和散热片协同导致的共模辐射.建立铝制带鳍散热片计算模型,应用有限元数值计算法分析散热器能量耦合及辐射发射机理,以屏蔽作为主要抑制手段,研究屏蔽板尺寸、放置位置及通风孔对共模辐射抑制效应,并进一步提出屏蔽板改进结构.计算结果表明:使用2块屏蔽板在正确放置时就可有效抑制辐射,且屏蔽板越长,对共模辐射抑制效果越好;屏蔽板上有孔缝存在,对应的辐射就要比无孔时高,开孔个数本身对辐射的影响并不大.改进后的结构对共模辐射抑制效果更优于原结构,尤其体现在3.9 GHz窄频带范围内.

针对POCT(point of care testing)场合对自动化、小体积和易操作的生化分析仪的需求,为基于离心式微流控芯片的生化分析仪设计一种基于ARM、MCU和DSP的多处理器控制系统.以S5PV210(ARM)为上位机,负责友好的人机交互、任务分配、数据管理等工作;以C8051F060(MCU)和TMS320F28335 (DSP)为下位机,负责运动控制、数据采集等实时性要求高的工作.多处理器采用串行通信,协同工作,多任务并行处理.采用嵌入式Linux为操作系统,Qt/Embedded为应用程序开发工具.实验结果表明,系统快速、稳定、操作简单,满足生化分析仪的POCT使用要求.

为了提高反作用飞轮工作的可靠度,并对飞轮的设计提出改进措施,本文进行了可靠性方面的研究.从飞轮的机械主体结构和驱动电路两方面对反作用飞轮的可靠性进行预计并找出反作用飞轮的可靠性薄弱环节.接着根据飞轮运行情况的分析建立故障树和故障模式,得到一些提高可靠性的措施.最后针对影响反作用飞轮可靠性比较大的驱动电路中的MOSFET驱动桥电路进行了具体分析,通过Simulink仿真和Multisim电路仿真,提出给驱动桥添加死区模块和冗余MOSFET管两个改进方法,并针对并联MOSFET管遇到的实际参数不匹配问题给出解决措施.

针对卫星高小型化、可靠性通信等要求,提出了一种以FPGA为主控制器,基于双路切换CAN总线通信的反作用飞轮控制系统的设计与实现方法.对CAN总线收发、报文解析、力矩与速度控制以及控制量测量等功能进行了模块化设计.对原理样机进行了测试实验,实验结果表明该系统具有良好的速度控制特性、力矩控制特性以及稳定的通信性能.所提出的报文解析方法,使上位机可以方便地通过可切换的双路CAN总线对反作用飞轮进行实时可靠地控制、遥测数据采集以及相关的故障处理.

To adapt to the size of the small satellite,improve the inertia/mass ratio of small satellite attitude control flywheel and lighten the weight of flywheel,a disk brushless DC motor used in flywheel was designed.According to the moment of inertia of the flywheel,the overall structure of the motor was designed and the armature diameter ratio was determined.After analyzing the motor magnetic circuit,the relationship between the magnet size and air gap length was derived.The Finite Element Method(FEM) was used to determine the number of pole pairs and get the method of calculating equivalent air gap flux density.After establishing the relationship between winding parameters and the motor rated data,the formulas of designing winding were proposed.Simulation method was used to analyze the Electromotive Force(EMF) of the motor.A prototype was manufactured with this method and tested.The results show that the maximum error is 6.3%,which proves the correctness of the design method.

To obtain both high sensitivity and high throughput when measuring at the same time,a static double-gain Hadamard spectrometer is introduced,based on micro-slit array.The principle and instrument structure of static double-gain Hadamard spectrometer are described,and spectra aliasing caused by Hadamard encoding mask is investigated.The relationship between spectral offset and the spatial offset of incident slit is obtained.For a given wavelength spectrum,the spatial offset caused by the spatial offset of incident slit is also calculated in theory.The simulation results show that this method has no complex computation,with fast correction,and is easy in program realization.

A prototype of the micro-flywheel system with the superconducting magnetic bearing has been designed. This micro-flywheel system adopts the superconducting magnetic bearing as the supporting mechanism, and the brushless planar DC motor as driving device. The maximum speed of the flywheel rotor is 15000rpm at 14. 4V and 0. 36A. Through the test of flywheel system＇s free spin-down curve of speed with the mechanical bearings and the superconducting magnetic bearing, the friction loss of different bearing is obtained, and the equivalent friction coefficient of the superconducting flywheel system is 0. 001-0. 007 under different rotational speed. Equivalent friction coefficient of the superconductivity hearing is found to increase along with the speed. The analysis indicated that the superconductivity magnetic bearing eddy current loss and the hysteretic loss also increase along with the rotational speed.

To improve the inertia / mass ratio of attitude control flywheel used in small satellite and lighten the weight of flywheel attitude adjustment system,a brushless DC motor used in flywheel was designed.According to the motor magnetic circuit,the corresponding relationship between the size and maximum energy of magnet was derived.The influence of magnetic circuit parameters on the flywheel performance was analyzed by using the Finite Element Method(FEM).For the flywheel structure feature of large equivalent air-gap and large ratio of diameter to length,a method for calculating air-gap magnetic flux density was proposed.The relationship between winding parameters and the motor rated data was established.Simulation method was used to analyze the motor performances.Compared with a flywheel motor with the angular moment of 5 Nms at the highest speed of 6 000 r/min,the maximum error is 6.5%,which proves the correctness of the design method.

To satisfy the requirements of small scale fully automatic biochemical analyzer system for multi-task,rigid real-time performance,and complicated data computation,the design method based on ARM double system on a chip(SoC) is proposed.The system is composed of S3C2440A(ARM) as the host computer,and C8051F060 as the slave computer;and serial port communication between ARM and single chip computer is adopted.ARM takes the responsibility for task allocation and data storage,via the master single chip computer,the reagent tray is located,and data are acquired,the rotation of the sampling arm and the sample feeding are controlled by the slave single chip computer,the multi-task parallel rapid processing is implemented;the embedded Linux and QT/E(QT/Embedded) are adopted to develop the system software.The experimental result shows that the system features good real-time performance on motion control,powerful calculation and processing capability,stable and reliable performance,etc,and it can totally satisfy the practical application requirements.