CHCA as a matrix facilitates the ionization of proteins and peptides in a matrix-assisted laser desorption/ionization(MALDI) time-of-flight(TOF) mass spectrometer. The matrix itself also ionizes and so do its adducts....CHCA as a matrix facilitates the ionization of proteins and peptides in a matrix-assisted laser desorption/ionization(MALDI) time-of-flight(TOF) mass spectrometer. The matrix itself also ionizes and so do its adducts. Matrix clusters and adducts interfere with peptide ionization and peptide mass spectrum interpretation, especially at low sample concentrations and within m/z 500-1 000 range. These matrix adducts, especially within m/z 500-1 000, are significantly reduced with addition of ammonium citrate, ammonium sulfate, ammonium benzoate, ammonium bicarbonate, ammonium citrate and potassium dihydrogen phosphate to the matrix and the samples were deposited onto the MALDI target. The reduction of matrix adducts improves peptide ionization and signal-to-noise ratio, which enhances the reliability of database searching.展开更多
本文提出了一种新的资料处理方法——速度谱约束(Constraints of Velocity Spectrum,CVS)。该方法首先对叠前CMP道集进行速度分析,拾取有效信号速度,经过动校正后利用横向滤波技术将校平后的信号和未校平的噪声分离;再进行反动校;再次...本文提出了一种新的资料处理方法——速度谱约束(Constraints of Velocity Spectrum,CVS)。该方法首先对叠前CMP道集进行速度分析,拾取有效信号速度,经过动校正后利用横向滤波技术将校平后的信号和未校平的噪声分离;再进行反动校;再次进行速度分析拾取干扰波速度,经过动校正后将校平的干扰波与未校平的有效信号分离,对分离的有效信号利用干扰波速度反动校后再利用有效信号速度动校正;最后进行水平叠加。该方法在提高资料信噪比的同时有效地提高了横向和纵向分辨率,且具有很好的保真度。展开更多
To find the optimized levels of various casting parameters in the ductile iron casting, various casting defects and the rejection rate were observed from a medium scale foundry. The controlled values of different cast...To find the optimized levels of various casting parameters in the ductile iron casting, various casting defects and the rejection rate were observed from a medium scale foundry. The controlled values of different casting parameters such as pouring temperature, inoculation, carbon equivalent, moisture content, green compression strength, permeability and mould hardness were selected. Three different melts of metal with 0.4wt.%, 0.6wt.%, and 0.8wt.% inoculation(Fe-Si-Mg alloy and post inoculant) were produced using a 1-ton capacity coreless medium frequency induction furnace. L-27 orthogonal array with 3-level settings were chosen for the analysis. Responses for each run were observed. The signal-to-noise(S/N) ratio for each run was calculated using the Taguchi approach, and the optimized levels of different casting parameters were identified based on the S/N ratio. The analysis of variance for the casting acceptance percentage concludes that inoculation is the most significant factor affecting the castings' quality with a contribution percentage of 44%; an increase in inoculation results in a significant improvement in acceptance percentage of ductile iron castings. The experiment results showed that with the optimized parameters, the rejection rate was reduced from 16.98% to 6.07%.展开更多
文摘CHCA as a matrix facilitates the ionization of proteins and peptides in a matrix-assisted laser desorption/ionization(MALDI) time-of-flight(TOF) mass spectrometer. The matrix itself also ionizes and so do its adducts. Matrix clusters and adducts interfere with peptide ionization and peptide mass spectrum interpretation, especially at low sample concentrations and within m/z 500-1 000 range. These matrix adducts, especially within m/z 500-1 000, are significantly reduced with addition of ammonium citrate, ammonium sulfate, ammonium benzoate, ammonium bicarbonate, ammonium citrate and potassium dihydrogen phosphate to the matrix and the samples were deposited onto the MALDI target. The reduction of matrix adducts improves peptide ionization and signal-to-noise ratio, which enhances the reliability of database searching.
文摘本文提出了一种新的资料处理方法——速度谱约束(Constraints of Velocity Spectrum,CVS)。该方法首先对叠前CMP道集进行速度分析,拾取有效信号速度,经过动校正后利用横向滤波技术将校平后的信号和未校平的噪声分离;再进行反动校;再次进行速度分析拾取干扰波速度,经过动校正后将校平的干扰波与未校平的有效信号分离,对分离的有效信号利用干扰波速度反动校后再利用有效信号速度动校正;最后进行水平叠加。该方法在提高资料信噪比的同时有效地提高了横向和纵向分辨率,且具有很好的保真度。
文摘To find the optimized levels of various casting parameters in the ductile iron casting, various casting defects and the rejection rate were observed from a medium scale foundry. The controlled values of different casting parameters such as pouring temperature, inoculation, carbon equivalent, moisture content, green compression strength, permeability and mould hardness were selected. Three different melts of metal with 0.4wt.%, 0.6wt.%, and 0.8wt.% inoculation(Fe-Si-Mg alloy and post inoculant) were produced using a 1-ton capacity coreless medium frequency induction furnace. L-27 orthogonal array with 3-level settings were chosen for the analysis. Responses for each run were observed. The signal-to-noise(S/N) ratio for each run was calculated using the Taguchi approach, and the optimized levels of different casting parameters were identified based on the S/N ratio. The analysis of variance for the casting acceptance percentage concludes that inoculation is the most significant factor affecting the castings' quality with a contribution percentage of 44%; an increase in inoculation results in a significant improvement in acceptance percentage of ductile iron castings. The experiment results showed that with the optimized parameters, the rejection rate was reduced from 16.98% to 6.07%.
