Advanced Materials Research Vols. 718-720

Abstract: This article introduced a fast and stable method on measuring the batches of trace moisture in ultra-purity ammonia gas .This method is based on ammonia decomposited reaction ,which occurs completely and irreversibly when ammonia is passed over nickel catalyst at high temperatures. While the trace water wapor passes though the catalyst unchanged. And the moisture of ammonia may be determined by measuring the dew point of the steam of hydrogen and nitrogen produced by decomposition of ammonia,combined with the trace oxygen content measured by GC,the content of trace moisture in ultra-purity ammonia gas can be got. Contrasted with Cavity Ring-down Spectroscopy (CRDS) and Infrared Absorption Spectroscopy (IR),Thermal Decomposition Dew Point method (TDDP) has high accuracy,good repeatability, stability and environmentally friendly.

Abstract: A fiber-optic dosimeter was developed using a plastic scintillating fiber, a plastic optical fiber, and a photomultiplier tube for measuring entrance surface dose over the low-energy range which is interested in diagnostic radiology. To evaluate the fabricated fiber-optic dosimeter, the scintillating light signals were measured by changing the current-time product whose values were determined by tube current and irradiation time of a digital radiography system. In conclusion, the trend of scintillating light signals of the fiber-optic dosimeter was similar with that of the entrance surface doses of a commercially available semiconductor dosimeter according to the current-time product.

Abstract: In order to identify the green tea quickly and accurately, the infrared spectra of teas measured by Fourier transform infrared spectroscopy are analyzed by using informatics method of feature extraction in this work. By comparing the different characteristic bases found by different feature genes of different tea samples, it is concluded that when green tea, yellow tea and white tea are chosen to constitute the standardized spectrum data matrix, and its first and third feature gene are selected to build characteristic basis, the green tea can be visually distinguished and the same samples have a very good aggregation. While when the characteristic basis is built by the first and second feature gene or the second and third feature gene, or the samples which are used to make up of standardized spectrum data matrix are all green tea, the recognition effect of green tea is bad. A linear arbiter of green tea is set up according to neutrality line principle on the above effectively characteristic basis, when all samples are projected onto the characteristic basis it is shown that all the green tea fall on the right of arbiter, and all not green teas are on the left of arbiter, consequently, the green tea can be identified.

Abstract: Nowadays, experiment and science research on apparel pressure are mainly about knitting wear which is the most closed to human body compared with other garment species. Yet there exists many tightly fitting styles in woman appeal using woven materials that might do harm to human body than the flexible knitting. In this article, we took experiment on western and eastern woman body using ELF system through modern western medicine and ergonomics angle concerning woman dress as the basic categories. 26 points where pressure will be strengthen while daily movement happened were tested, in this way we described the human pressure sensitivity through building the map. Finally, we compared it with traditional Chinese medicine theory. Thus the phenomenon how human body feels pressure was analysis through two perspective of medicine. Moreover, the result of woman body comfortable feelings in different points would be helpful in clothing design and structure building progress of woman apparel.

Abstract: This paper investigates some approaches to improve the accuracy of parameter estimation in geodetic Very Long Baseline Interferometry (VLBI). By analyzing the radio source Sky Coverage (SC) for each antenna, a new approach, the method of condition number is proposed to find out reasonable time ranges for zenith wet delay (ZWD) estimation. The relative accuracy of Earth Orientation Parameters (EOP) is tested after implementing the method of condition number and the result shows that the relative accuracy of EOPs could be improved by ~3% with compared to the equal time range of 20min for ZWD estimation for CONT sessions.

Abstract: A wide frequency band DC corona current measurement system is introduced in this paper. GPS technology is applied to make sure that the voltage and current signal are collected synchronously. The wide band corona current signal is transmitted to the lower computer by the wireless network of 300M/s. The wide frequency band DC corona current waveform was gained in the Ultra High Voltage (UHV) Test Base in Wuhan, which can reflect the high frequency pulses of the corona current, and corona currents of 6 bundle conductor LGJ630-45 in dry and rain (rain rate 20mm/h) conditions are gained. The corona current in the rain condition is much larger than that in the dry condition.

Abstract: Our workgroup have exploited 8 channels DVB-C transport stream monitor which accords with the standard of our country. The most notable characteristic is that this DVB-C transport stream monitor is high capacity transport stream monitor. It can monitor eight channels digital television program at the same time .There is no enterprise which can produce 8 channels DVB-C transport stream monitor at present.The real-time monitoring and management system is a very important part of 8 channels DVB-C transport stream monitor. This paper introduces the significance and theory of DVB-C transport stream monitor. Then, it gives an implementation of the real-time monitoring and management system of 8 channels DVB-C transport stream monitor.

Abstract: Gas insulated switchgears occupy an important position in the power system. But the partial discharge would occur because of insulation defect, PD will lead to the GIS insulation damage after a long time, and will lead to serious consequences without treatment in time, therefore, the PD detection is particularly important. PD is detected by its secondary physical phenomena, including the phenomena of sound, light, electromagnetic waves and gas decomposition products and so on. At present, many scholars in China and foreign countries have done a comprehensive study on insulation detection technology of GIS and have achieved a large number of results. The author do a detailed overview on the detection technical of GIS insulation state, including GIS platform and the simulation of typical insulation defectspartial discharge detection methods, SF₆ alternative gas and pattern recognition. These works provide a valuable reference for follow-up study of GIS.

Abstract: The basic principle of the wavelet analysis method to extract the mineral spectral absorption characteristics is summarized and different wavelet bases,wavelet decomposition scale extraction effect are analyzed in this paper. Then, the algorithm of mineral spectral absorption characteristics based on wavelet spectral analysis is provided and a large number of experiments are carried out using the spectrums of field rock mineral. Experimental result shows that such a method is less affected by original signal noise and depict the parameters of the mineral spectral absorption feature more precise, which is an ideal spectral feature extraction method compared with the traditional mineral spectral absorption feature extraction method.

Abstract: In order to improve the performance of localization using RFID technology and to reduce the localization error, Fisher information matrix including the state parameters was adopted to evaluate the systems performance. The proper placement of reference tags was analyzed to improve the localization accuracy of RFID system. The results of computer simulation show that we can determine the optimal geometric distribution model of reference tags and the optimal distribution model is not unique according to the characteristics of the geometric distribution. This work is significant for improving the localization accuracy of RFID system.