[Objective] This research aimed to explore the method to increase conversion rate of pollen-tub pathway in Chinese cabbage.[Method] Chinese cabbage varieties Yuqing and No.03 were used as materials for the selection o...[Objective] This research aimed to explore the method to increase conversion rate of pollen-tub pathway in Chinese cabbage.[Method] Chinese cabbage varieties Yuqing and No.03 were used as materials for the selection of germination buffer and parameters for ultrasonication.[Result] The optimal buffer for pollen germination of Chinese cabbage was 200 g/L sucrose ＋ 100 mg/L boric acid ＋ 200 mg/L calcium nitrate,the preferred ultrasonic processing power was 150 W,processing time was 5 s,interval time was 5 s and processing frequency was 8.Three T1-generation plants were obtained through selection with 200 mg/L kanamycin.[Conclusion] This research laid foundation for the further genetic transformation of Chinese cabbage.展开更多
A new method in digital hearing aids to adaptively localize the speech source in noise and reverberant environment is proposed. Based on the room reverberant model and the multichannel adaptive eigenvalue decompositi...A new method in digital hearing aids to adaptively localize the speech source in noise and reverberant environment is proposed. Based on the room reverberant model and the multichannel adaptive eigenvalue decomposition （MCAED） algorithm, the proposed method can iteratively estimate impulse response coefficients between the speech source and microphones by the adaptive subgradient projection method. Then, it acquires the time delays of microphone pairs, and calculates the source position by the geometric method. Compared with the traditional normal least mean square （NLMS） algorithm, the adaptive subgradient projection method achieves faster and more accurate convergence in a low signal-to-noise ratio （SNR） environment. Simulations for glasses digital hearing aids with four-component square array demonstrate the robust performance of the proposed method.展开更多
Attenuating the undesired audio noise generated by impulse noise,such as shot and scream of brakes,is specially useful for real-time audio recording of TV or broadcasting live report.On the basis of impulse noise dete...Attenuating the undesired audio noise generated by impulse noise,such as shot and scream of brakes,is specially useful for real-time audio recording of TV or broadcasting live report.On the basis of impulse noise detection algorithms based on template,this paper improves the method of establishing the template by using multiple microphones to pick up noise corrupted signals and impulse noises in the environment.The universal of thresholds is found and a detection algorithm with slope as the characteristic is proposed by comparing a variety of feature extraction algorithms.The proposed algorithm gets a significant improvement in testing speed and accuracy,which means it is suitable for real-time processing of audio signals.展开更多
The application of railway wheel noise compensation method is considered. The effect can be obtained by shift a pair of usual parallel rail joints on a pair of offset rail joints, for example, the right rail joint is ...The application of railway wheel noise compensation method is considered. The effect can be obtained by shift a pair of usual parallel rail joints on a pair of offset rail joints, for example, the right rail joint is shifted concerning the left rail joint on the certain distance. The distance is depend on the speed of train and promotes the correlation interconnection between excited acoustical pulses. The intensity wheel knock spectrograms corresponding of different distance between rail joints registered by the microphone are estimated. The spectrograms considerably differed from each other in low frequency band are analyzed. The result of practical using the acoustic noise compensation method is proved.展开更多
基金Supported by Scientific and Technological Project in Shanxi Province(021034)Scientific Research Project of Shanxi Academy of Agri-cultural Sciences (YGX-01)~~
文摘[Objective] This research aimed to explore the method to increase conversion rate of pollen-tub pathway in Chinese cabbage.[Method] Chinese cabbage varieties Yuqing and No.03 were used as materials for the selection of germination buffer and parameters for ultrasonication.[Result] The optimal buffer for pollen germination of Chinese cabbage was 200 g/L sucrose ＋ 100 mg/L boric acid ＋ 200 mg/L calcium nitrate,the preferred ultrasonic processing power was 150 W,processing time was 5 s,interval time was 5 s and processing frequency was 8.Three T1-generation plants were obtained through selection with 200 mg/L kanamycin.[Conclusion] This research laid foundation for the further genetic transformation of Chinese cabbage.
基金Supported by the National Natural Science Foundation of China (60872073)~~
文摘A new method in digital hearing aids to adaptively localize the speech source in noise and reverberant environment is proposed. Based on the room reverberant model and the multichannel adaptive eigenvalue decomposition （MCAED） algorithm, the proposed method can iteratively estimate impulse response coefficients between the speech source and microphones by the adaptive subgradient projection method. Then, it acquires the time delays of microphone pairs, and calculates the source position by the geometric method. Compared with the traditional normal least mean square （NLMS） algorithm, the adaptive subgradient projection method achieves faster and more accurate convergence in a low signal-to-noise ratio （SNR） environment. Simulations for glasses digital hearing aids with four-component square array demonstrate the robust performance of the proposed method.
基金Supported by the Research on Multi-channel Audio Noise Reduction Algorithm(No.3132014XNG1430)
文摘Attenuating the undesired audio noise generated by impulse noise,such as shot and scream of brakes,is specially useful for real-time audio recording of TV or broadcasting live report.On the basis of impulse noise detection algorithms based on template,this paper improves the method of establishing the template by using multiple microphones to pick up noise corrupted signals and impulse noises in the environment.The universal of thresholds is found and a detection algorithm with slope as the characteristic is proposed by comparing a variety of feature extraction algorithms.The proposed algorithm gets a significant improvement in testing speed and accuracy,which means it is suitable for real-time processing of audio signals.
文摘The application of railway wheel noise compensation method is considered. The effect can be obtained by shift a pair of usual parallel rail joints on a pair of offset rail joints, for example, the right rail joint is shifted concerning the left rail joint on the certain distance. The distance is depend on the speed of train and promotes the correlation interconnection between excited acoustical pulses. The intensity wheel knock spectrograms corresponding of different distance between rail joints registered by the microphone are estimated. The spectrograms considerably differed from each other in low frequency band are analyzed. The result of practical using the acoustic noise compensation method is proved.
