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PROPORTION OF DISTINCT ZEROS OF A DIRICHLET L-SERIES

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Acta Mathematica Scientia 2022年第6期42卷 2367-2376页

作者： Xinhua QIN xiaosheng wu School of Mathematics Hefei University of TechnologyHefei 230009China

By studying the distribution of zeros of combinations of a Dirichlet L-function and its first-order derivative,we prove that every Dirichlet L-function has more than 66.7934%distinct zeros.

关键词： simple zeros distinct zeros Dirichlet L-function

STUDY OF ARTIFICIAL EYES HAVING HIGH STRENGTH AND LOW DENSITY

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Journal of wuhan University of Technology(Materials Science) 1999年第4期14卷 28-32页

作者： LI xiaosheng wu Guangfu Qiqihar University Qiqihar University China Dept. of Mat. Sci. and Engineering Qiqihar University Qiqihar 161006 China

The artificial eyes having high strength, low density and naturalmovement, which are made from hydroxyapatite and bioactive glass havebeen utilized ef- fectively in clinic. The technology of compoundinghydrox- yapatite, melting bioactive glass and making he artificaleyes are stated in this paper. In animal test, the bioactivity andbiocompatibility of the material making the artificial eyes areexamined by histological observation, SEM XRD and electronic *** the same time, application of the artificial eyes in clinic arealso introduced.

关键词： artificial eye seat natural movement hydroxyapatite

Resonance Characteristics of Piezoelectric Resonator Based on Digital Driving Circuit of Field-Programmable Gate Array

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Journal of Shanghai Jiaotong university(Science) 2019年第1期24卷 1-6页

作者： WANG Zhenyu wu xiaosheng SHU Shengzhu National Key Laboratory of Science and Technology on Micro/Nano Fabrication Shanghai Key Laboratory of Navigation and Location Based ServicesDepartment of Micro/Nano ElectronicsShanghai Jiao Tong University

Piezoelectric resonators are widely used in frequency reference devices, mass sensors, resonant sensors(such as gyros and accelerometers), etc. Piezoelectric resonators usually work in a special resonant mode. Obtaining working resonant mode with high quality is key to improve the performance of piezoelectric resonators. In this paper, the resonance characteristics of a rectangular lead zirconium titanate(PZT) piezoelectric resonator are studied. On the basis of the field-programmable gate array(FPGA) embedded system, direct digital synthesizer(DDS) and automatic gain controller(AGC) are used to generate the driving signals with precisely adjustable frequency and amplitude. The driving signals are used to excite the piezoelectric resonator to the working vibration mode. The influence of the connection of driving electrodes and voltage amplitude on the vibration of the resonator is studied. The quality factor and vibration linearity of the resonator are studied with various driving methods mentioned in this paper. The resonator reaches resonant mode at 330 kHz by different driving *** relationship between resonant amplitude and driving signal amplitude is linear. The quality factor reaches over 150 by different driving methods. The results provide a theoretical reference for the efficient excitation of the piezoelectric resonator.

关键词： piezoelectric resonators resonant mode quality factor linearity field-programmable gate array(FPGA)

High Precision Temperature Measurement for Microfluidic Chip Applications

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Journal of Shanghai Jiaotong university(Science) 2022年第5期27卷 699-705页

作者： XIONG Yuefu wu xiaosheng ZENG Zhaofeng HUANG Shan CHEN Tianpei National Key Laboratory of Science and Technology on Micro/Nano Fabrication Department of Micro/Nano ElectronicsShanghai Jiao Tong UniversityShanghai200240China

Biochemical reaction in microfluidic chip is sensitive to *** precise control in a small size device requires the temperature measurement with high measurement *** temperature measurement method usually measures the voltage drop of the thermistor,which is excited by a constant current *** method requires the constant current source with high precision and *** output of the constant current source is influenced by environmental factors,resulting in a larger measurement *** solve this problem,a proportion method,a two-layer filtering algorithm,and a power management technique were applied to improve the temperature measurement *** proportion method can reduce the low frequency fluctuation *** two-layer filtering algorithm can reduce the high frequency fluctuation error *** power management technique used can improve the system *** testing the temperature measurement system built,the experimental results show that the fluctuation error can be significantly decreased from 0.5◦C to 0.2◦C.

关键词： microfluidic chip temperature measurement proportion method two-layer filtering algorithm fluctuation error

High Resolution Differential Capacitance Detection Scheme for Micro Levitated Rotor Gyroscope

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Chinese Journal of Aeronautics 2007年第6期20卷 546-551页

作者： Huang Xiaogang Chen Wenyuan Liu wu Zhang Weiping wu xiaosheng Key Laboratory for Thin Film and Microfabrication Technology of Ministry of Education National Key Laboratory of Nano/Micro Fabrication Technology Institute of Micro and Nano Science and Technology Shanghai Jiao Tong University Shanghai 200030 China

A differential capacitance detection circuit aiming at detection of rotating angle in a novel levitation structure is presented. To ensure the low non-linearity and high resolution, noise analysis and non-linearity simulation are conducted. In the capacitance interface, an integral charge amplifier is adopted as a front end amplifier to reduce the parasitic capacitance caused by connecting wire. For the novel differential capacitance bridge with a coupling capacitor, the noise floor and non-linearity of the detection circuit are analyzed, and the results show that the detecting circuit is capable of realizing angle detection with high angular resolution and relative low non-linearity. With a specially designed printed circuit board, the circuit is simulated by PSpice. The practical experiment shows that the detection board can achieve angular resolution as high as 0.04° with a non-linearity error 2.3%.

关键词： MEMS micro gyroscope capacitance sensing inertial sensor angle detection

The Garden of the World——Visiting the '99 China Kunming International Exposition on Horticulture

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Women of China 1999年第9期 23-25页

作者： wu xiaosheng A RONG

THE biggest garden in the world openedas the’99 Kunming InternationalExposition on Horticulture(EXPO’99)drewback its curtains. A scenic area covering 218 hectares inthe northern part of Kunming City has beenselected as the site of the *** the gate,visitors will see"thecentury flower-clock”welcoming *** isprobably the biggest open air flower-clock inthe world,made up of 1,500 potted flowers,with its diameter of 19.99 meterssymbolizing the year *** 800-meter-

关键词： The Garden of the World China Kunming International Exposition on Horticulture Visiting the

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基于纹理谱及其空间特征的图像检索

高技术通讯 2010年第8期20卷 822-827页

作者：孙君顶毋小省河南理工大学计算机科学与技术学院焦作454000 河南省控制工程重点学科开放实验室焦作454000

针对传统纹理谱描述符维数较高且忽略了空间特征的问题,一方面进一步考虑邻域中心像素与其它像素间的灰度关系,改进了中心对称局部二值模式纹理谱描述符,另一方面基于灰度共生矩阵提出了纹理谱基元共生矩阵的概念,并据此来提取纹理谱基... 详细信息

针对传统纹理谱描述符维数较高且忽略了空间特征的问题,一方面进一步考虑邻域中心像素与其它像素间的灰度关系,改进了中心对称局部二值模式纹理谱描述符,另一方面基于灰度共生矩阵提出了纹理谱基元共生矩阵的概念,并据此来提取纹理谱基元空间特征。通过不同图像库进行实验,结果表明,结合所提取的空间特征,可明显地提高传统纹理谱描述符的检索性能,而且所提出的描述符以较低的维数取得了较好的检索效果。

关键词：纹理谱局部二值模式(LBP) 中心对称局部二值模式(CS-LBP) 纹理谱基元共生矩阵(TSCM) 图像检索

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人工神经网络和电阻抗谱法压电材料快速表征

压电与声光 2024年第2期46卷 234-240页

作者：向辉吴校生上海交通大学微米纳米加工技术全国重点实验室上海200240 上海交通大学电子信息与电气工程学院上海200240

压电材料作为重要的功能材料,广泛应用于社会的各领域,但其弹性常数的偏差会导致应用过程中出现错误的设计,弹性常数的正确表征对压电器件的正确设计尤为重要。与其他测量方法相比,电阻抗谱仅需要阻抗分析仪即可实现测量,通过测量阻抗... 详细信息

压电材料作为重要的功能材料,广泛应用于社会的各领域,但其弹性常数的偏差会导致应用过程中出现错误的设计,弹性常数的正确表征对压电器件的正确设计尤为重要。与其他测量方法相比,电阻抗谱仅需要阻抗分析仪即可实现测量,通过测量阻抗谱反演获得压电材料的弹性常数。传统电阻抗谱法通过不断修正材料参数,使得测量阻抗谱和计算阻抗谱最大程度吻合,该过程需要多次迭代,计算量大,耗时较长。该文提出采用神经网络建立阻抗谱到弹性常数的正向模型,测量得到阻抗谱后仅需一次正向计算即可得到弹性常数。使用Comsol和Matlab联合仿真建立数据集,引入丢弃法避免模型过拟合,利用Pytorch建立模型,经过训练后,最大谐振频率偏差从初始2.8%降至0.8%。该技术为压电材料弹性常数精密测量提供可靠的理论与实践途径。

关键词：压电材料表征电阻抗谱法人工神经网络弹性常数矩阵

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翼型前缘变形对动态失速效应影响的数值计算

航空学报 2014年第4期35卷 986-994页

作者：卢天宇吴小胜北京理工大学宇航学院北京100081

翼型或机翼的动态失速效应所引起的低头力矩和正气动阻尼限制了飞行器气动性能的提高,甚至可能诱导发生不稳定运动。应用于小尺寸机翼的前缘动态变形(DDLE)技术,通过实时改变前缘形状,能够改善翼型前缘区域的速度梯度,进而抑制动态失速... 详细信息

翼型或机翼的动态失速效应所引起的低头力矩和正气动阻尼限制了飞行器气动性能的提高,甚至可能诱导发生不稳定运动。应用于小尺寸机翼的前缘动态变形(DDLE)技术,通过实时改变前缘形状,能够改善翼型前缘区域的速度梯度,进而抑制动态失速效应。采用转捩剪切应力输运(SST)黏性模型结合分区混合动态网格技术,研究了这种前缘变形对机翼俯仰运动所引起的非定常流动的影响,得到通过小幅度前缘变形抑制和延迟动态失速的方法,从而提高翼型的气动性能。翼型NAC A0012的数值模拟结果与动态失速风洞试验结果比较表明:所使用的数值计算方法能够较为准确地模拟翼型在动态失速过程中升力系数与俯仰力矩系数的变化情况,可用于研究前缘变形对翼型俯仰运动所引起的非定常流动的影响。前缘动态变形翼型俯仰运动过程的非定常流场的数值模拟表明:在大迎角下不同幅度的前缘下垂运动能够抑制流动分离的发生,从而抑制动态失速,但在大迎角下小幅度高频率的前缘下垂变形能更高效地抑制动态失速;前缘变形幅度以及变形沿中弧线的分布对升力系数和俯仰力矩系数的影响并不明显。

关键词：翼型动态失速前缘动态变形混合动态网格非定常流动数值计算