Advanced Materials Research Vols. 718-720

Abstract: This research developed and optimized the methods for simultaneous determination of tetracycline (TCs), macrolide (MLs) and sulfonamide (SAs) antibiotics in soils using accelerated solvent extraction (ASE)- solid-phase extraction (SPE)-high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Methanol-citric acid (pH=4.7) was used as extraction solvent, diatomite (washed by EDTA) was used as dispersing agent. Firstly, soil was extracted by ASE with the parameter conditions: pressure 1500 psi, temperature 70°C, static 10 min, 1 circle, then pre-concentration by SPE and followed by HPLC-MS/MS analysis. Recovery was 86.3%~97.4% for SAs, 67.3%~87.4% for TCs and 68.4%~78.3% for MLs. RSD < 9 % and r > 0.99. Limits of detection (LOD) was 0.5~0.9 ug/kg for SAs, 0.2~1.1 ug/kg for TCs and 0.2~0.3 ug/kg for MLs. This method determined 9 kinds of antibiotics within 15 min, the determination accuracy can meet the requirements of actual analysis.

Abstract: A PXI-based microwave interferometer system is constructed to measure the velocity of interior ballistic ammunition. The hardware and software structure of the system is introduced. Wavelet denoising and polynomial chirplet transform is used to process motion signals. Finally, experiments are conducted aiming at the launching process of a certain object, and results show that the proposed system is of high efficiency to calculate the velocity-time, displacement-time and acceleration-time curve of the ammunition. As an experimental case study, the proposed system has been applied to interior ballistic measurement.

Abstract: Resistive dividers have been widely applied in the field of high voltage pulse measurement because of its simple structure, fast response, large power and low distortion rate [1], but measurement inaccuracy is usually coming when the rise time of pulses is less than 10ns. In the article the effects on the response characteristic are investigated theoretically and experimentally and it puts forward a solution that a mid-electrode is joined to transform the distributed capacitance into the one from high voltage side to mid-electrode and the one from mid-electrode to earth in series connection. A new resistive divider with mid-electrode is designed with high voltage side of 10.2kΩ, low voltage side of 10.01Ω and ratio of 1061.86. It is revealed that the divider has excellent response characteristic with the step response time of less than 1.6ns and the measurement uncertainty of less than 1%.

Abstract: The accuracy of the data detection can be affected by speed of in-pipeline MFL detector during non-destructive testing of gas pipeline. So speed regulation of in-pipeline MFL detector is researched in this paper. Speed regulation of in-pipeline MFL detector can be seen as change of speed under different steady state. In-pipeline MFL detector and up-down stream gas are regarded as a particle. According to principles of fluid mechanics, the relationship of pressure of pipeline and speed of in-pipeline detector is analyzed and pressure-speed model of in-pipeline detector is built. The speed of in-pipeline detector is calculated under different steady state based on pressure-speed model for the purpose of speed adjustment. The results of simulation in the Second West-East natural gas pipeline show that the speed of in-pipeline detector can be accurately calculated and effectively adjusted.

Abstract: In MEMS parameter measure based on vision,the process of binarization is critical. In the situation of unbalancing illumination and noise background,the performance of traditional binarization method degrades. In this paper, a binarization method based on wavelet analysis and an optimal box counting (OBC) fractal dimension algorithm is proposed. At first,wavelet analysis is used to eliminate the effect of illumination distribution.Then the MEMS image binarization based on OBC reduces the effect of noise. Experiments show that, the method can get a considerable binarization result.

Abstract: The test method of 32 channel X-ray readout integrated circuit (ROIC) has been proposed in this paper. Large resistors and a voltage source with high accuracy are used to generate 32 channels of weak currents, which are injected into the ROIC. Some key parameters of ROIC such as linearity, uniformity, cross talk, dynamic range have been tested. This method helps to test ROICs performance and does not need any photodiode and any laser light, which is convenient and easy to be realized.

Abstract: This paper introduced an online system about tool observation based on USB microscope. By programing on the upper computer realized the visualized operations about the image data collection, processing and display. then combined with the CMOS digital microscopes hardware which based on USB2.0 communication bus, analyzed and solved matching work between the data transmission that based on USB interface and CMOS image collection. In the meantime, realized image collection, real-time display, and the general processing operations about image that follow up. At last, Through the test and verified the stability and reliability about this observation system. At the same time, analyzed the feasibility about observe the beating of flat chisel using USB microscope.

Abstract: A body-size measurement method based on checkerboard matching is proposed. First, calibrated cameras are used to acquire two body images after projecting chess boards on human body with projector. Then, the parallax of the two images is got by feature extraction and stereo matching. Finally, we can calculate the 3D coordinates of the human body according to the principle of binocular vision to complete the acquisition of body size. The result shows that measurement error is ± 4%. This study can measure automatically and improve precision compared with traditional methods while it has low-cost, simple operation compared with the non-contact measurement. And the results accuracy can meet its general application in practice.

Abstract: The analysis method that the microwave digestion - graphite furnace atomic absorption spectrometry (GF-AAS) determination of trace impurity element arsenic in the nanotitanium dioxide has been built. It uses a mixture digestion reagent which is composed of a certain concentration and the proportion of hydrofluoric acid and nitric acid in the experiments, and then combined with high pressure microwave heating technology so as to quickly and completely digest the nanotitanium dioxide sample into solution. The composition and ratio and amount of the mixed digestion reagent, and the best microwave heating control program are all optimized in this paper, which not only solved the problem of the digestion of titanium dioxide and the loss of the analyte arsenic that is likely to be volatile in the high temperature digestion process, but also ensure that high content of titanium matrix in the low acidity solution is still existing in a stable complex ion form to avoid hydrolysis by complexation of the fluoride ion. Therefore, it can greatly reduce the detection affection of acidity and avoid the erosion of GF-AAS graphite tube. In order to eliminate the influence of the thermal stable titanium dioxide matrix on the determination of volatile trace element arsenic, the type of graphite tube, graphite furnace atomization procedures and atomic absorption spectrometer detection parameters all have been optimized through the matrix effect testing. The detection limit is 0.000 001% and the recovery rate is in the range of 93.0% to 106.0%. Otherwise, RSD is less than 9.36%, which is consistent with ICP-MS detection method.

Abstract: In the paper a measurement technique for study main technical and physical parameters of nanocluster non-volatile memory capacitance cell is presented. The charging/discharging process features associated with nanoclusters (nanocrystals) incorporated into gate dielectric are discussed. Original equipment for fast capacitance measurements based on computer interfaces is considers.