汽油超声喷嘴的设计研究

为了进一步细化汽油雾化粒径,该文基于一维振动理论研究设计了一种汽油超声喷嘴。采用有限元法分析振动模态和谐响应,获得其谐振频率、振动位移与工作应力分布,理论频率30.157kHz与HP-4286A LCR精密阻抗测试仪实测频率30.862kHz接近。此外,对超声喷嘴的汽油雾化效果进行了理论计算分析与试验研究,理论计算粒径?24.38μm,实测粒径?27.62μm,两者基本一致,比传统汽油喷油嘴的雾化粒径(约?50μm)缩小约2倍。研究结果有效地改善了汽油的雾化质量,提高了燃油利用率。     

双激励超声波椭圆振动磨削装置设计及优化

基于ANSYS Workbench多目标驱动模块对双激励超声波椭圆振动磨削(UEVG)装置进行优化设计。基于等效电路法设计前盖板是λ/4(λ为波长)复合变幅杆的半波长换能器,先后建立带有载物台的变幅杆及UEVG装置的参数化模型进行模态、谐响应分析。根据10个设计点模态分析确定变幅杆最优尺寸,在此基础上通过42个设计点仿真分析获得UEVG装置的谐振频率、节面位置与结构尺寸的关系,并优化尺寸。优化后UEVG装置的谐振频率与理论设计频率的误差为0.24%,振幅高达16.7μm。     

基于有限元模型的超声切割刀优化设计

超声切割刀在材料加工领域中有广泛的应用前景,可用于切割各种复合材料等硬脆材料。该文利用ANSYS有限元分析软件建立超声切割刀的有限元模型,对其进行模态分析和谐响应分析。仿真结果显示,超声切割刀在40kHz频率附近存在轴向纵振模态,其振动节点位于安装环和压电陶瓷中心线上,符合设计要求。基于有限元模型研制超声波切割刀,通过阻抗分析仪与激光多谱勒测振仪对换能器的固有频率与响应进行测试,获得的超声切割刀阻抗曲线平滑,谐振频率为40.261kHz,设计误差为0.83%,最大振幅达到14.52μm,结果与有限元计算相互吻合。     

基于压电材料的振动能量收集器的谐振频率调节

振动能量收集器的最大输出电压发生在共振状态,因此其谐振频率应与环境振动频率一致.针对振动能量收集器与环境频率不匹配的问题,采用单自由度模型分析了悬臂梁-质量块结构的振动能量收集器谐振频率等性能,加工并测试了压电式的微型振动能量收集器样机,结果谐振频率的误差最大为6％.通过质量调节方法进一步将样机的谐振频率调节了10.5 Hz的宽度.针对50 Hz的振动环境,将谐振频率为58.7 Hz的样机调节到了50.4 Hz,输出电压提高了4倍.     

多层压电陶瓷变压器振动模态分析与测量

介绍了多层压电陶瓷变压器振动的原理,利用有限元分析研究了多层压电陶瓷变压器的振动模态,并利用激光多普勒干涉仪测量了多层压电陶瓷变压器在不同输入电压下两种谐振状态下沿长度方向的位移振幅。实验表明：谐振频率的测量值和有限元计算结果相符;谐振状态下压电陶瓷变压器长度方向的振幅与输入电压的关系是在输入电压较小时,基本上是线性变化的,并且逐渐趋于饱和,输入端振幅略大于输出端。     

纵振超声刀柄优化设计研究

基于硬脆材料难加工的问题,在传统刀柄基础上进行改进设计出超声刀柄。以纵振超声刀柄为研究对象,利用Ansys对其进行模态和谐响应分析,得到刀柄各节点振型和幅频曲线。仿真结果表明,超声刀柄在23kHz频率附近存在轴向纵振模态,其振动节点位于变幅杆锥面上。用激光多普勒测振仪与阻抗分析仪测试超声刀柄刀具和尾部振幅及阻抗曲线。测试结果表明,谐振频率为23.9kHz时,最大振幅达到10.54μm,与仿真基本一致。最后通过在刀柄上安装平衡环,达到刀具振幅增大,刀柄尾部振幅减小的效果,提高了超声刀柄实际加工中的精度和稳定性。     

一种低功耗多谐振荡式电压频率转换器设计

提出一种新型的低功耗多谐振荡式电压频率转换器电路的设计,采用0.18μm CMOS工艺制程,拥有较大的输入电压范围,根据CSMC 0.18μm工艺参数,在Spectre上仿真。结果表明,该电路在0~1.6 V的输入电压下输出0~2.0 MHz的频率信号,灵敏度1.25 MHz/V,输出频率相对误差小于6.8%,电路的最大功耗0.23 m W。得到预期的设计结果。     

压电式微固体模态陀螺谐振频率自动跟踪电路

压电式微固体模态陀螺振子通过交变电压激振、传感电极感应出电荷。当激励电压频率为某阶振动模态谐振频率时,感应电荷达到最大值。设计了谐振频率自动跟踪电路,使陀螺稳定工作在谐振模态。使用现场可编程门阵列(FPGA)控制直接数字频率合成器(DDS)产生频率精确可调的激励电压,驱动陀螺振子振动。检测谐振点对应的激励电压和感应信号间的相位差,作为反馈信号调节激励电压频率。实验结果表明,当相位差锁定区域处在98.48°~100.27°时,振子感应电极输出信号最大,振子处于谐振状态,实现了振子谐振频率的跟踪锁定。该系统可用于以谐振器为核心器件的振子工作模态锁定与跟踪。     

一种直角螺旋悬臂梁结构的压电能量收集器

提出了一种2π弧度的直角螺旋悬臂梁结构的压电能量收集器。该设计一方面可以降低谐振频率,另一方面可以提高单位体积的能量收集效率。悬臂梁整体结构厚度为2 mm,宽度为6 mm,整体尺寸大小为22 mm×26 mm。当施加的激励为0.1g加速度时,仿真输出电压为1.95 V,测量输出电压为1.8 V,相对电压误差为7.7%;仿真谐振频率为269 Hz,测量谐振频率为265 Hz,相对频率误差为1.5%;理论输出功率为7.04μW,测试输出功率最大为5.79μW,相对功率误差为17.8%。该压电能量收集器适用于便携式微电子系统。     

新型锥壳形旋转超声电机的研究

该文提出了一种新型锥壳形旋转行波超声电机,该锥壳形超声电机振子的三阶弯曲振动模态可以将面内、外弯曲振动结合起来,实现新型振动模式的行波驱动。利用有限元软件确定了振子结构尺寸、三阶弯曲振型及频率并制作了原理样机,对原理样机振动特性及输出性能进行了测试。测试结果表明,当激励电压峰峰值为240 V,谐振频率为27.53 kHz时,空载时超声电机最高转速为85.8 r/min,堵转力矩为441 mN·mm。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.