OALib Journal期刊

ISSN: 2333-9721




2019 ( 64 )

2018 ( 440 )

2017 ( 395 )

2016 ( 526 )


匹配条件: “ Xiang-E Sun” ,找到相关结果约207921条。
Graphical User Interface Design of FIR Filter  [PDF]
Myagmardorj Bayasgalan, Xiang-E Sun
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104709
FIR digital filter is a stable linear phase filter. Relying on the powerful computing power of MATLAB software and its GUI platform, this graduation project has completed the GUI design and implementation of FIR digital filter through programming. Through the FIR filter to achieve the program, you can design and implement a variety of amplitude characteristics of the FIR digital filter, according to the user input filter design indicators, select the corresponding filter design method (window function, frequency sampling method) to design the corresponding filter. According to the different amplitude characteristics, the parameters of the filter design parameters will change accordingly; when the Kaiser window design filter is selected, the user is allowed to input the stopband attenuation of the filter; when using the frequency sampling method to design the filter, the user must input the filter length and the transition zone sample value; when the parameter is entered incorrectly, the system will prompt for an error message. GUI can also provide intuitive filter amplitude characteristics, phase characteristics and the unit impulse response graphics to help users to confirm whether the design of the filter meets the design specifications; by setting the global shortcut keys, the user after all parameters and options is confirmed by the Shortcut keys to achieve the rapid implementation of filter design.
The Finite-Precision Numerical Effects Analysis of Infinite Impulse Response  [PDF]
Ganbaatar Nandintsetseg, Xiang-E Sun
Open Access Library Journal (OALib Journal) , 2019, DOI: 10.4236/oalib.1104719
This paper mainly uses the MATLAB software to design IIR digital filter with the amplitude frequency characteristic method and zero-pole method, and then analyzes the effect of coefficient quantization and quantization effects in IIR digital filter arithmetic. It is that we can use the software to draw some pictures. These pictures can show coefficient system function of IIR digital filter with a certain length to quantify the zero pole after the system distribution, frequency response, after quantizing the coefficients under the direct, parallel and cascade structures, as well as the limit cycle oscillation and the overflow oscillation of fixed-point operation in the quantization effect of operation are drawn.
Application of the gravity technique on detection of the Earth''''s free oscillations

SUN He-ping,LEI Xiang-e,Hsu Hou-ze,

地球物理学进展 , 2005,
Abstract: 地球自由振荡是一种十分重要的地球动力学现象,用重力技术检测地球自由振荡,结合地震技术可为获得地球内部精细结构提供一种重要手段.本文概要综述了地球自由振荡理论研究的发展和重力技术检测现状,详细讨论了利用我国武汉超导重力仪检测到的地球自由振荡本征周期和谱峰分裂现象,结合我国实际情况提出了研究展望,旨在给出需解决的学科问题和相应的策略探讨.
Role of Downward Momentum Transport in the Formation of Severe Surface Winds
LIU Xiang-E,GUO Xue-Liang,
LIU Xiang-E
,GUO Xue-Liang

大气和海洋科学快报 , 2012,
Abstract: The Weather Research and Forecasting (WRF) model was used to investigate the role of downward momentum transport in the formation of severe surface winds for a squall line on 3–4 June 2009 across regions of the Henan and Shandong Provinces of China. The results show that there was a strong westerly jet belt with a wind speed greater than 30 m s-1 and a thickness of 5 km at an altitude of 11–16 km. The jet belt was accelerated, and it descended while the squall line convective system occurred. It was found that the appearance of strong negative perturbation pressure accompanied by the squall line caused the acceleration of the upper-level westerly jet and increased the horizontal wind speed by a maximum of 18%. Meanwhile, the negative buoyancy due to the loading, melting, and evaporation of cloud hydrometeors induced the downward momentum transport from the upper levels. The downward momentum transport contributed approximately 70% and the surface cold pool 30% to the formation of severe surface winds.
Light Scattering of Gaussian Beam from an Eccentrically Stratified Dielectric Sphere and Application

YAN Bing,HAN Xiang-e,REN Kuan-fang,LI Xiang-zhen,

光子学报 , 2009,
Abstract: Based on the generalized Lorenz-Mie theory(GLMT),the scattering characteristics of an eccentrically stratified dielectric sphere situated on-axis of a Gaussian beam were studied.The beam shape coefficients were calculated by integral localized approximation.The translational addition theorems for spherical vector wave functions and the boundary conditions were used in solving the scattering coefficients.The eccentrically stratified dielectric sphere model was used to study the scattering characteristics of ...
Effects of exogenous spermidine on active oxygen scavenging system and bound polyamine contents in chloroplasts of cucumber under salt stress
外源亚精胺对盐胁迫下黄瓜(Cucumis sativus L.)叶绿体活性氧清除系统和结合态多胺含量的影响

DUAN Jiu-Ju,GUO Shi-Rong,KANG Yun-Yan,ZHOU Guo-Xian,LIU Xiang-E,

生态学报 , 2009,
Abstract: The objective of this study was to investigate the effects of exogenous application of spermidine on the growth, active oxygen scavenging system and bound polyamine contents in chloroplasts of cucumber under salt stress. The results showed that under salt stress, exogenous spermidine increased TGase activity and bound putrescine, spermidine, spermine and total polyamine contents in chloroplasts. The activities of SOD, APX and GR, the contents of AsA, Car and GSH, and the ratios of GSH/GSSG in chloroplasts were increased, while the ratios of DAsA/AsA and the contents of H2O2 and MDA decreased. Furthermore, exogenous spermidine increased net photosynthetic rates, as well as alleviated the salt-induced plant growth inhibition. These results suggest that exogenous application of spermidine could alleviate salt-induced membrane injury of chloroplast by increasing the active oxygen scavenging ability and the bound polyamine contents in chloroplast.
Effects of salt stress on cucumber seedlings root growth and polyamine metabolism

DUAN Jiu-ju,GUO Shi-rong,KANG Yun-yan,LI Jing,LIU Xiang-e,

应用生态学报 , 2008,
Abstract: By the method of water culture, this paper studied the effects of NaCl stress on the seedlings root growth and polyamine metabolism of two cucumber cultivars 'Changchun mici' and 'Jin-chun No. 2'. The results showed that under NaCl stress, root growth was inhibited, and lipid peroxidation and electrolyte leakage increased. These changes were more obvious in salt-sensitive 'Jin-chun No. 2' than in salt-tolerant 'Changchun mici'. NaCl stress caused an increase of agrinine decarboxylase (ADC), ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC) activities in cucumber roots, which was much greater in 'Changchun mici' than in 'Jinchun No. 2'. At the highest value, ADC, ODC and SAMDC activities increased by 149.3%, 60.1% and 69.4% in 'Changchun mici' and 118.6%, 56.2% and 50.6% in 'Jinchun No. 2', respectively, in comparison with the control. Diamine oxidase activity increased in 'Changchun mici' but not in 'Jinchun No. 2', and the increment of polyamine oxidase activity in 'Changchun mici' was smaller than that in 'Jinchun No. 2'. As a result, the contents of free spermidine and spermine and of conjugated and bound polyamines in 'Changchun mici' increased significantly, while that of free putrescine had a significant increase in 'Jinchun No. 2'. It could be concluded that higher levels of free spermidine and spermine and of conjugated and bound polyamines and lower level of free putrescine in roots could improve the adaptability of cucumber seedlings to salt stress.
Research on Speech Endpoint Detection Algorithm with Low SNR  [PDF]
Jian Wei, Xiange Sun
Open Access Library Journal (OALib Journal) , 2017, DOI: 10.4236/oalib.1103487
The detection of speech endpoint is an important application for speech signal processing. Although there are variance methods, the endpoint can’t be detected accurately in low SNR (Signal to Noise Ratio). The paper pointes out an endpoint detection algorithm combining two methods together: the one is improved spectral subtraction based on multitaper spectral estimation, and the other is BARK subband variance in frequency domain. Firstly, the noisy speech signal is processed though the improved spectral subtraction based on multitaper spectral estimation. It can achieve the purpose of noise reduction through this step. Then the noisy speech signal is detected using the method of BARK subband variance in frequency domain. Compared with the common endpoint detection algorithm, it is concluded that endpoint detection accuracy by new method can be improved in low SNR.
Design of the Brushless DC Motor Driving System Based on STM32  [PDF]
Haoran Jin, Xiange Sun
Open Access Library Journal (OALib Journal) , 2017, DOI: 10.4236/oalib.1103703
As a mechanical and electrical integration product, brushless DC motor has better controllability and wide speed range. According to its characteristics, a brushless DC motor control system based on STM32F103ZET6 MCU is designed and realized, and then the control system was analyzed and discussed. Adopted GPIO module, PWM module, timer module, etc., coupled with efficient PID algorithm, three main functions of this system have been implemented, such as start stop control, position detection and closed-loop speed regulation. The experimental results show that this control system works well with low cost and high price-performance ratio.
Check of free oscillation signal with SG data
Xiange Lei,Houze Xu,Heping Sun
Chinese Science Bulletin , 2002, DOI: 10.1360/02tb9346
Abstract: The observation of the Earth’s free oscillation is an important way to study the Earth’s inner structure and geophysical parameters. Many geophysicists have investigated the Earth’s normal modes with strainmeters and spring gravimeters. Since the superconducting gravimeters appeared, people have gained a new kind of more stable instruments to detect the normal modes. The measurement for the Earth’s free oscillation with the superconducting gravimeters is one of the main goals of the Global Geodynamics Project. In this note, we have investigated the Earth’s normal modes excited by Peru Ms 7.9 Earthquake on June 23, 2001 with the superconducting gravimeter C032 at the Wuhan station. After having completed the subtraction of gravity tides with the 20th order polynomial fitting, and the correction for pressure and the analysis of the noise spectrum of the superconducting gravimeter, we accurately observed all base normal modes from 0 S 0 to 0 S 32 and the splittings of 0 S 2 and 0 S 3. Those results show a good agreement with the HB1 model.

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