Image processing technology is used to process the transmission electron microscope (TEM) pictures for improving the
definition of the TEM images, giving prominence to the characteristics of crystal materials and obtaining useful crystal
structure information. The language we have used is Matlab.7.0. To improve the articulation of the TEM images,
different method is used according to the characteristics of the pictures, including contrast self adapting histogram
homogenizing, filter noises and so on. Fourier transformation is used for analyzing the structure of nanocrystal materials.
Edge detection method is used to enhance the granular character. Detecting the intensity distribution method is used for
distinguishing the nanocrystal tube and nanocrystal granule. It can also be used to analyze decentrality and homogeneity
of the nanocrystals granular. In order to measure the dimension of the nanocrystal more precisely, we distinguish the
points with larger changes in grey level by using the function "edge".
Proc. SPIE. 7658, 5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optoelectronic Materials and Devices for Detector, Imager, Display, and Energy Conversion Technology
KEYWORDS: Agriculture, Electrodes, Glasses, Dielectrics, Power supplies, Optical testing, Time metrology, Signal detection, Temperature metrology, Liquids
In gas discharge, various self-organized structures are formed as the applied voltage is increased. A noticeable
phenomenon is that the system undergoes twice hexagon structure. One is observed in the lower voltage range and the
other is in the higher voltage range. To study the intrinsic mechanism, the light signal, electric signal, and the emission
spectrum of the two hexagons is measured by photoelectric detect method. The electric signal is detected by high-voltage
probe. The light signal is measured distinguished in time and space by using diaphragm. The electron excitation
temperature is measured using spectrum method. It is conclude that the forming mechanism of the two kinds of hexagon
is different. The lower-voltage hexagon is a dynamic multiplex structure, while the higher-voltage hexagon is a single
static structure. The excitation temperature of higher-voltage hexagon is higher than that of lower-voltage hexagon.
A computer aided process planning system is developed based on laser bar code technology to automatize and
standardize processing-paper making. The system sorts fittings by analyzing their types, structures, dimensions, materials,
and technics characteristics, groups and encodes the fittings with similar technology characteristics base on the theory of
Group Technology (GT). The system produces standard technology procedures using integrative-parts method and stores
them into technics databases. To work out the technology procedure of fittings, the only thing for users need to do is to
scan the bar code of fittings with a laser code reader. The system can produce process-paper using decision trees method
and then print the process-cards automatically. The software has already been applied in some power stations and is
praised by the users.
In this work, rutile Sn-doped TiO2 nanocrystals are synthesized by hydrothermal method, with TiCl4 and SnCl4 aqueous
solutions serve as the precursors. When the TiCl4 and SnCl4·5H2O serve as precursors with ratio of Ti4+/Sn4+ 4:1, most of
the Synthesized crystals are square morphology, with diameter of 30nm. When the ratio of Ti4+/Sn4+ changed to about 1:1,
the obtained samples display various kinds of morphology. Some of them are tiny square crystals with the size less than
20nm. The bigger ones is about 100-120nm in length and 30-50nm in diameter. And the aspect ratio is about 3:1. When
the ratio of Ti4+/Sn4+ is 0:1, the crystals is 20nm in diameter, and 30-120nm in length. The results indicate that
combination of Ti4+ and Sn4+ has relative evident effect on the crystals morphology. The component of the obtained
samples has been analyzed by X-ray energy dispersive spectroscopy (EDS). The result shows that the highest atomic
percent concentration of the doped-Sn is very low. The experiments results indicate that it is hard for other metal ions to
dope into the rutile TiO2 by the way of lattice-substitute.
In this work, we present some practical methods for analyzing and processing the TEM (transmission electron
microscope) images with Matlab, among which including "adjusting the images", "adumbrating the units", "filtering the
noise in the images", and so on. To improve the resolution of the TEM pictures, we use form boards to process the
elements in the input pictures. The form boards are set up according to the characteristics of the input TEM images. In
order to measure the dimension of the nanocrystal more precisely, we distinguish the points with larger changes in grey
level by using the function "edge" to get the structure information of the images. To make the morphology of the crystals
more clearly, we adjust the images by mapping the brightness of the original patterns to a new range of value, which can
be realized with the function "imadjust". To obtain the brightness distribution in the images can help us analyzing the
dispersive property of the nanocrystals. The brightness distribution in the patterns can be obtained with the function
"improfile", which computes the intensity values in the image by using interpolation arithmetic.
A dielectric barrier discharge system is specially designed with two liquid electrodes and a corresponding
photoelectricity detection system. The detection system is composed of lens, apertures, multiplier-tube, digital camera,
and an oscilloscope. A rich variety of emission patterns are obtained in the system as the voltage is increased. The
wavelength characteristic of the emission patterns in dielectric barrier discharge is investigated. It is found that the
wavelength of the emission patterns displays a non-monotonic variation as the applied voltage is increased. When the
applied voltage is relatively low, the wavelength of the emission patterns decreases as the applied voltage increases.
When the applied voltage is increased over a critical value, the wavelength of the patterns becomes larger as the voltage
is increased. The wavelength of the emission pattern may maintain approximately invariable when the voltage is
increased within some particular voltage range.
In this work, we present some practical methods for analyzing the structure of spatial-temporal patterns with Matlab, including "Fourier transform", "obtaining the sketch of the pattern", "obtaining the brightness distribution in the pattern",
"filtering the noise in the pattern", and so on. The types of the patterns can be determined by obtaining the spatial frequency spectrum of the patterns using Fourier transform. To obtain the sketches of the patterns can make the measurement of pattern structure parameters easier and more accurately. To obtain the brightness distribution in the patterns can help us to analyze the physics mechanism of the pattern formation systems. To filter the noise in the patterns can make the pattern pictures more clearly. This work can provide a beneficial reference for researchers who study pattern dynamics in different systems.
In this work, a rich variety of emission spiral patterns have been obtained in dielectric argon/air barrier discharge (DBD) system with a special designed water electrodes setup. We investigate the characteristics of spiral patterns with two kinds of different sidewall materials. By analyzing the image and the light signals of the patterns, it is found that spiral patterns with different sidewall material have different characteristics. The profile of the intensity distribution curve under the glass sidewall appears as a sinusoidal oscillation, while displays in relaxation oscillation mode under plastic sidewall. The space frequency spectrum of spirals under glass sidewall contains only one order spectrum, while the space spectrum of spirals under plastic sidewall contains more than two orders of space frequency spectrum. The experiment results indicate that the sidewall material may affect the excited property of the discharge system.
Glow dielectric barrier discharge appears as an attractive solution to realize near atmospheric pressure cold plasma process suitable for all the surface treatments including thin film coating and material making. Such development requires a large understanding of the dielectric barrier discharge (DBD) physical and chemical process. The objective of this work is to contribute to that understanding. In this paper, we report the results of the measurement of the spectrum from 690nm to 800nm in DBD in argon. The electron temperature Te has been estimated using intensity ratio method by optical emission spectroscopy under difference experimental conditions. According to Local Thermodynamic Equilibrium (LTE) theory, the electron temperature Te can be assumed equal (equals) to the excitation temperature Texc, namely Te=Texc=T. Therefore, the plasma temperature T can be determined by comparing the relative intensities of spectral lines from the same element and ionization stage. The spectral lines 763.72nm (2P6→1S5) and 772.63nm (2P2→1S3) of Ar atom are chosen to estimate the electron excitated temperature. The experimental results show that the electron excitated temperature is in the range of 0.3-8eV in Ar under different pressures. The results also show that the electron excitated temperature increases with the decreasing of the applied voltage. The results provide a reference for the controlling of DBD and are of great importance to the industrial applications.
Pattern formation is a process by which a spatially uniform state loses stability to a non-uniform state. A usual effective method for studying the property of patterns is to take pictures or record images of the patterns with digital cameras and get useful information from them. In this work, the structure, the spatial frequency spectrum of the patterns, the precise location of the discharge filaments center and the distribution of the light emission density of filaments are analyzed with Matlab6.1. This work can provide a beneficial reference for researchers who study pattern dynamics in DBD system or other systems.
Dielectric barrier discharge is a novel system for studying the pattern formation. In this system, spiral pattern has been observed for the first time. For the element of the pattern emits itself, the image can be obtained to give some information about the behavior of the spiral pattern. The image of spiral pattern is analyzed based on the software Matlab6.1. The spatial distribution of the intensity in the image gives a normal spiral structure. The temporal distribution of the intensity shows that the spiral pattern has a periodical behavior in a second time scale. All of the results are consistent with the theoretical simulations.