中国科学院机构知识库网格系统: 检索

Alternative coulometric signal readout based on a solid-contact ion-selective electrode for detection of nitrate 期刊论文 OAI收割
ANALYTICA CHIMICA ACTA, 2020, 卷号: 1129, 页码: 136-142
作者: Wang, Hemin; Yuan, Baiqing; Yin, Tanji; Qin, Wei

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收藏 | 浏览/下载：82/0 | 提交时间：2021/06/16

Coulometric signal Solid-contact ion-selective electrode Electrical double layer capacitance Ordered mesoporous carbon NO3-

CO2 laser enhances the chilling tolerance of wheat seedlings by stimulating NO synthesis 期刊论文 OAI收割
CANADIAN JOURNAL OF PLANT SCIENCE, 2016, 卷号: 96, 期号: 5, 页码: 796-807
作者: Chen, Dong; Liu, Qiang; Chen, Yi-ping

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收藏 | 浏览/下载：27/0 | 提交时间：2018/10/26

Triticum Aestivum Co2 Laser Chilling Stress No Signal Reactive Oxygen Species Stress Tolerance

Improved TOPS about direction of arrival estimation for wideband signals (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Vibration, Structural Engineering and Measurement, ICVSEM2011, October 21, 2011 - October 23, 2011, Shanghai, China
作者: He B.

收藏 | 浏览/下载：17/0 | 提交时间：2013/03/25

The study about the direction-of-arrival (DOA) estimation for wideband signals is a basic topic of Signal Processing. The method called test of orthogonality of projected subspaces (TOPS) does not require initial values to form focusing matrix compared with the coherent signal subspace method (CSSM) but it has poor performance for coherent wideband signals at low signal-to-noise ratio (SNR). Based on the lack of the conventional TOPS this paper reconstructs a set of new matrices with the narrowband correlated matrices coming from the DFT decomposition of the array output and modifies the method frame of the conventional TOPS. So we get a set of reconstructed matrices with full rank corresponding to each frequency bin and which have no array aperture loss. The improved TOPS can estimate the DOA for coherent wideband sources at low SNR and enhances the performance of the conventional TOPS. Simulation results show that the improved TOPS is effective and the total performance of which is similar to the rotational signal-subspace (RSS) method. (2012) Trans Tech Publications.

Application of trend extrapolation method to spectrum analysis of microtremor signal (EI CONFERENCE) 会议论文 OAI收割
2nd World Congress on Computer Science and Information Engineering, CSIE 2011, June 17, 2011 - June 19, 2011, Changchun, China
Zhou X.; Guo T.; Jiao J.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

The trend extrapolation method is applied to spectrum analysis of microtremor signal in order to increase the spectral estimation accuracy. First establish an appropriate extrapolation model based on the existing data series and then fit correlation functions other than existing data by derivative least squares method finally perform spectrum analysis using extrapolated correlation functions. Numerical simulations and the experimental results show that good results are achieved no matter correlation functions change slow or rapid and the extrapolation error is not more than 2.3%. 2012 Springer-Verlag Berlin Heidelberg.

The angular velocity estimation principal of -- filter based on high sampling rate (EI CONFERENCE) 会议论文 OAI收割
2011 2nd International Conference on Mechanic Automation and Control Engineering, MACE 2011, July 15, 2011 - July 17, 2011, Inner Mongolia, China
作者: Zhang Y.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

In order to get angular velocity of stabilization servo mechanism from angular position sensors -- filter and its angular velocity transfer function were predigested. Combing with optimum parameters -- filter based on high sampling rate was established the effect of and sample rate on filter nature frequency were evaluated. According to the requirements of stabilization platform the principle of steady and transient tracking filter differential were proved. With the hypothesis of constant acceleration the frequency characteristics of angular velocity transfer function were analyzed three-dimensional Kalman filter was simplified and the filter parameters were designed. The results show that when the spectrum of input signal was lower than 6rad/s parameters was 0.02 and sampling period were 0.08ms and 0.1ms respectively the filter can realize differential exactly when the spectrum was 9rad/s the precision was no less than 1.1% the phase leading of angular position was no less than 70 the natural frequency should be higher than the cut-off frequency of stabilization platform was two or three times. In the engineering of electro-optical stabilization servo mechanism -- filter has properties of tracking differential and reached the requirement of platform angular velocity estimation. Also it is one of the effective methods to get angular velocity from angular position sensors. 2011 IEEE.

Design of transmission of high-speed CCD driving signals (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Mechatronic Science, Electric Engineering and Computer, MEC 2011, August 19, 2011 - August 22, 2011, Jilin, China
作者: Zhang S.

收藏 | 浏览/下载：70/0 | 提交时间：2013/03/25

In order to overcome the distortion problem of CCD driving signals caused by signal transmission the detail implementation of transmission of high-speed CCD driving signals based on transmission line theory is discussed. The CCD driving signals are critical to the CCD to produce high quality images. In high speed application these drivers will occupy more circuit board areas and can not be put very close to the CCD. So the driving signals must be transmitted. Because the CCD exhibits capacitive load the driving signals distortion problem is much severe. Transmission line theory is used to analyze the problem. The method of source termination is adopted to avoid signal reflections. Meanwhile the characteristic impedance of the circuit board and the resistance of terminal resistor are designed small enough to decrease the rising and falling time of the driving signals. Experimental results show that there is no distortion of the high speed driving signals after transmission. 2011 IEEE.

Design and image restoration research of a cubic-phase-plate system (EI CONFERENCE) 会议论文 OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, April 26, 2010 - April 29, 2010, Dalian, China
作者: Zhang J.; Zhang J.; Zhang J.; Shi G.; Zhang X.

收藏 | 浏览/下载：25/0 | 提交时间：2013/03/25

Wave-front coding technology is a novel jointly optical and digital imaging technology which can greatly extend the depth of focus of optical systems. The image restoration process is an important part of wave-front coding technology. Using wave-front coding makes the modulation transfer function(MTF) values of the optical systems change little over a range of several times the depth of focus which means the system MTF is quite insensitive to defocus and there is no zero in the passband. So we can design a single filter for the restoration of images in different defocus positions. However it's hard to avoid noise during image acquisition and transmission processes. These noises will be amplified in the image restoration especially in the high frequency part when the MTF drop is relatively low. The restoration process significantly reduces the system signal to noise ratio this way. Aimed at the problem of noise amplification a new algorithm was proposed which incorporated wavelet denoising into the iterative steps of Lucy-Richardson algorithm. Better restoration results were obtained through the new algorithm effectively solving the noise amplification problem of original LR algorithm. Two sets of identical triplet imaging systems were designed in one of which the cubic-phase-plate was added. Imaging experiments of the manufactured systems were carried and the images of a traditional system and a wave-front coded system before and after decoding were compared. The results show that the designed wave-front coded system can extend the depth of focus by 40 times compared with the traditional system while maintaining the light flux and the image plane resolution. 2010 Copyright SPIE - The International Society for Optical Engineering.

Micro assembled fourier transform spectrometer (EI CONFERENCE) 会议论文 OAI收割
4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, November 19, 2008 - November 21, 2008, Chengdu, China
作者: Liang J.-Q.; Zhang J.; Zhang J.; Zhang J.; Wang B.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

With the trend of minimization of Fourier transform spectrometer (FTS) which is particularly pronounced in many applications a model of a micro FTS with no moving parts is proposed and analyzed. During analyzng the gradients which mainly introduce phase error are accounted. Based on these assumptions and the improved Mertz phase correcting method the spectrum of signal is simulated with real extended light source. The resolution can be up to 3.43nm@800nm with high signal-to-noise ratio (SNR) limiting resolving ability 6.8dB. In addition the fabrication method of components are illuminated and demonstrated which can not only make it bear some advantages over conventional micro dispersive spectrometers but also afford some new concepts on the design of spectrometers with improved performance. 2009 SPIE.

Analysis and modelling of no-reference video quality assessment (EI CONFERENCE) 会议论文 OAI收割
2009 International Conference on Computer and Automation Engineering, ICCAE 2009, March 8, 2009 - March 10, 2009, Bangkok, Thailand
Tian Y.; Zhu M.

收藏 | 浏览/下载：20/0 | 提交时间：2013/03/25

Video processing system may introduce some amounts of distortions in the video signal. It is crucial to measure the video quality blindly for most image processing applications which could not obtain the original image. Different Video Quality Assessment (VQA) methods are analysis in this paper. A state of art in the field of No- Reference (NR) VQA is presented. Finally an ideal NR VQA model is proposed. 2009 IEEE.

Implementation and stability analysis of the fuzzy controller based on electric-driven simulation turntable (EI CONFERENCE) 会议论文 OAI收割
ISECS International Colloquium on Computing, Communication, Control, and Management, CCCM 2008, August 3, 2008 - August 4, 2008, Guangzhou, China
Xie M.-J.; Wang L.-M.; Wang Z.-Q.

收藏 | 浏览/下载：21/0 | 提交时间：2013/03/25

Fuzzy controller was used to resolve the problem of fast tracking and overshoot in electric-driven simulation turntable for its essence belongs to PD control In this system the control rules of fuzzy controller were established according to the step dynamic response process for the speed loop of this system was predigested to be second-orders system. The describing function method was adopted to analyze the stability of the fuzzy control system. It gave the information of stability of system intuitively. The fuzzy controller had been applied in this system successfully. The simulation turntable had no overshooting nearly when its step input signal was close to 90. Experimental results show the implementation method of fuzzy controller is not only simple but also effectual in engineering practice. It also provides an approach of design of fuzzy controller for motion control system. 2008 IEEE.