光的多普勒效应及其应用

本文介绍和探讨光的多普勒效应在天体物理最新发现中的应用及其效应机制，进一步深入了解光的本性及应用前景。     

基于钻削刀具后刀面刃磨方程建立的研究

采用锥面磨削法刃磨钻削刀具的后刀面,可显著提高刀具的使用寿命,有利于保证工件加工精度和提高工件表面质量。利用数控加工设备进行锥面磨削或者进行锥面磨削设备的研制中,关键是数学模型（后刀面方程）的建立;据此编制和计算机床坐标值的程序、对刀具刃磨机床进行研制。针对锥面磨削方法中钻削刀具后刀面方程的建立和有关参量的计算作深入的研究。并以该后刀面方程完成刀具刃磨机床的初期开发研制。     

Detection of vowel-like speech: an efficient hardware architecture and it's FPGA prototype

Microsystem Technologies - In this paper, a robust vowel-like speech (VLS) detection method using modified non-local means normalization factor (MNLM-NF) and it’s FPGA prototype is proposed....     

Improved magnetic and piezoresponse behavior of cobalt substituted BiFeO3 thin film

Piezoresponse force microscopy (PFM) technique has been utilized to characterize the nanoscale electromechanical properties of chemical solution deposited pristine (BiFeO₃, BFO) and 5% Cobalt-substituted bismuth ferrite (BiFe_0.95Co_0.05O_3, BFCO) thin films. Distinct PFM contrast was observed on the films' surface both in out-of-plane and in-plane modes. Piezoresponse signal was larger in BFCO film than BFO and the former film also exhibited negative self polarization. The calculated self polarization factor was − 0.94. Lateral signal (in-plane) changed its sign upon 180° sample rotation which ruled out spurious electrostatic contribution and confirmed piezoelectric nature of the effect. Square patterns were written by local poling and reversible nature of the piezoresponse behavior was established. Well saturated piezoelectric hysteresis loops were acquired with improved piezoelectric coefficient value in case of Co-substituted BFO film. The effect has been described on the basis of polarization rotation with doping. Magnetization of BFO film also increases with Co-substitution. The enhancement in magnetic and ferro/piezoelectric properties should be useful for multiferroic applications.     

Design,simulation and analysis of micro electro‐mechanical system microneedle for micropump in drug delivery systems

This article reports on the mechanical strength analysis and flow characteristics of square tip and circular tip microneedles by employing highly potent drugs that are given in extremely little quantity (microlitres) using MEMS technology, which proves to be a significant component of micropump in the application of Bio‐MEMS. These microneedles are well suitable for a MEMS‐based micropump in the drug delivery systems. It is an essential part of the micropump through which the drug is released into the patient’s body. The proposed microneedles can withstand a stress of 23 MPa and 20 KPa. An extensive investigation on selection of material for the microneedle is carried out to meet the requirements of the biocompatibility and high yield, as well as tensile strength. As mighty drugs such as vasopressin, atropine and digoxin are administered in large quantities, the microneedle is designed so as to deliver 800 µl of drug, with each microneedle delivering 90 µl. in a 3 3 array. 3 × 3 array releasing 90 µl.     

多流道旁通筛管性能实验评价

在海上油田砾石充填作业中,由于设计、井眼不规则、地层等原因导致充填不完全或充填失败,严重影响油井产量。设计研发了一种新型多流道旁通筛管,在常规充填结束后,旁通通道继续对亏空段进行充填。通过自研的大型全尺寸水平井度砾石充填实验模拟系统,对所设计的多流道旁通筛管进行了性能评价。结果表明,在无砂桥旁通管砾石充填实验中,旁通段充填效率为100.0%,连接输送玻璃管时出口处返液流量与输送玻璃管返液流量比为0.68 : 1,相比清水实验,旁通通道内的液体流量大幅提高;与有砂桥旁通管砾石充填实验相比,常规筛管充填效率提高62.5%,出口处返液流量与输送玻璃管返液流量比为1.60 : 1。实验证明,新型筛管的旁通性能和输送性能良好,砾石充填效率高。     

Structure,Ferroelectric, Dielectric and Energy Storage Studies of Ba0.70Ca0.30TiO3, Ba(Zr0.20Ti0.80)O3 Ceramic Capacitors

Ba_0.70Ca_0.30TiO₃-(BCT),Ba(Zr_0.2Ti_0.8)O₃-(BZT) ceramics were fabricated by conventional mixed oxide route to develop inorganic dielectric materials suitable for use as an insulator with high dielectric constant and low energy loss for capacitor applications. The structural phase transition, ferroelectric, dielectric and energy storage properties of BCT, BZT ceramic capacitors were investigated. Room temperature X-ray diffraction (XRD) patterns revealed prominent peaks corresponding to tetragonal perovskite crystal structure for both BCT, BZT solid solutions. Slim ferroelectric hysteresis (P-E) loops were observed for BCT, BZT solid solutions. Temperature dependent dielectric property measurements of BCT, BZT solid solutions have shown a high dielectric constant and low dielectric loss. Room temperature (300K) breakdown field strength and energy densities were obtained from the integral area of P-E loops. For the BCT ceramics, the largest recoverable energy (unreleased energy) density is 1.41 J/cm³ with dielectric breakdown strength as high as 150 kV/cm. For the BZT ceramics, the largest recoverable energy (unreleased energy) density is 0.71 J/cm³ with dielectric breakdown strength as high as 150 kV/cm. Bulk BCT, BZT ceramics have shown interesting energy densities; these might be the strong candidate materials for capacitor applications.     

Design and performance analysis of uniform meander structured RF MEMS capacitive shunt switch along with perforations

Microsystem Technologies - This paper presents design and simulation of uniform structured RF MEMS capacitive shunt switch using FEM tool and HFSS software. The switches with different shaped...     

高职机械制造与自动化专业创新型人才培养模式的研究

从目前高职机械制造与自动化专业人才培养模式存在的问题出发,探索并构建高职机械制造与自动化专业创新型人才培养模式,提出高职机械制造与自动化专业创新型人才培养模式的实现途径。     

Temperature Dependent Magnetic, Dielectric Studies of Sm-Substituted Bulk BiFeO3

Bismuth ferrite- (BiFeO₃) ceramic is the most studied and attractive multiferroic material with low magnetization, moderate leakage current, and low polarization. Samarium substituted bulk BiFeO₃ prepared at low synthesis temperature ??600?°C by the sol?Cgel process. Room temperature X-ray diffraction (XRD) patterns confirmed the formation of perovskite structure Bi_0.9Sm_0.10FeO₃ (BSFO) phases. Present compositions possess high dielectric constant (????199) and low dielectric loss (tan????0.009) at room temperature for 100?Hz frequency. Room temperature dielectric permittivity and dielectric loss decreased with increasing frequency from 100?Hz to 10 MHz. As the temperature increased, an enormous increase in both dielectric permittivity and dielectric loss is observed at all frequency regions. Temperature dependent M?CH hysteresis loops were saturated. Spin glass-like ferromagnetic behavior is retained in M?CH hysteresis loops measured from the low temperature region and normal ferromagnetic behavior is observed in the high temperature region, both at room temperature and above ??350?K, 400?K, respectively. The origin of the ferromagnetic property in BSFO may be due to the presence of rare earth metal ions at the lattice sites of?BFO.