In this work, a textured surface structure of Si substrate has been prepared using pyramid structure ZnO glass as
mask, and the structure of textured surface and reflection characteristics of Si substrate have been analyzed by scanning
electron microscope (SEM) and reflectivity spectra. The results show that U-shaped structure is formed on the surface of
photoresist after the incidence of ultraviolet light, and it is caused by the different decrement of light intensity in the ZnO
glass Mask Blank. The U-shaped structure which is same with the photoresist appears at the surface of Si substrate after
reactive ion etching (RIE) process, and the size of U-shaped structure is in the range of 0.5-1.5 μm. Needle-like
morphology caused by the RIE process appears on the U-shaped structure. The reflectivity of the U-shaped Si surface is
decreased by the needle-like morphology, and it is protected by the U-shaped structure. The textured structure etched at
different pressure is further investigated, and the results suggest that the reflectance of the sample reduces firstly and then
increases with the decrease of pressure, and a minimal average reflectance is obtained at 0.8 Pa. The ion damage of Si
surface is reduced in the second texturing process, which is useful for film deposition. The results suggest that low
reflectance and textured surface of Si substrate can be obtained by ZnO glass mask blank with natural pyramid structure,
which is meaningful for light trapping in solar cells.
In this paper, a combined method have been put forward for one ASTER detected image with the wavelet filter to
attenuate the noise and the anisotropic diffusion PDE(Partial Differential Equation) for further recovering image contrast.
The model is verified in different noising background, since the remote sensing image usually contains salt and pepper,
Gaussian as well as speckle noise. Considered the features that noise existing in wavelet domain, the wavelet filter with
Bayesian estimation threshold is applied for recovering image contrast from the blurring background. The proposed PDE
are performing an anisotropic diffusion in the orthogonal direction, thus preserving the edges during further denoising
process. Simulation indicates that the combined algorithm can more effectively recover the blurred image from speckle
and Gauss noise background than the only wavelet denoising method, while the denoising effect is also distinct when the
pepper-salt noise has low intensity. The combined algorithm proposed in this article can be integrated in remote sensing
image analyzing to obtain higher accuracy for environmental interpretation and pattern recognition.
Since computer tomography (CT) image has been widely applied in clinic diagnostics, while for many applications the
information directly provided by CT images is incomplete corrupted by noise or instrument defect, there has great
demand to further the processing methods for improving the CT image quality. Among all image features, the edge
profile of clinic focus has obvious influence on accurately translating CT image. In this paper, the wavelet filtering
algorithm based on modulus maximum method is put forward to extract and enhance the CT image edges. Edges in the
brain lobe CT image can be outlined after wavelet transform, during which the wavelet assigned as the first order
derivative of Gauss function. Further manipulation through maximum threshold checking to the modulus have been
attenuated the pseudo-edges. After segmented with the original CT image, the edge structure has been distinctly
enhanced, and high contrast is achieved between the brain lobe microstructure and the artificially established edges.
The proposed algorithm is more efficient than the common first order differential operator, for the latter it even
deteriorates the edge features. The algorithm proposed in this article can be integrated in medical image analyzing
software to obtain higher accuracy for symptom interpretation.
The microcapsules can act as novel optical functional material in which the optical recording substance such as
color-forming substance, photoinitiator and prepolymer are encapsulated. In this paper, the microcapsules with average
particle diameter of 300nm are prepared with interfacial polymerization method. The optical responding character of the
microcapsule is analyzed based on IR spectra and image density technique. Results show that the microcapsule material
encapsulated prepolymer TMPTA and photoinitiator Irgacure-ITX, TPO has thermal phase-change at 140°C, at which
the penetrability of the microcapsule has the highest efficiency. With the increase of exposure time, the reduction in
absorption intensities of the prepolymer TMPTA are observed at 1635cm-1 of C=C stretching and 898cm-1 of C-H
stretching on the C=C molecular bond. Such a result can be ascribed to the double bond cleavage process of the
prepolymer TMPTA is initiated by the optical-exposed photoinitiator, and superpolymer network is formed. The image
density contrast between the unexposed and exposed microcapsule is enhanced with exposure time increased.
UV photocuring technology has encountered increased applications in recent years, which finds a variety of applications on protective coating of the optical-fiber, ink and optical recording materials. Combined with techniques of photohardenable, microcapsule, heat-sensitive and interface-polymerization method, a novel photoheat sensitive recording material of non-silver salt is explored in this thesis. Microcapsules are particulate substance with a core and shell structure, where photopolymerizable composition, monofunctional/polyfunctional diluents, photopolymerization initiator, photosensitivity enhancing agent and dye precursor are encapsulated as the internal phase. In this paper introduced the characteristics and curing mechanism of photo-sensitive microcapsule materials. The photocuring process may be a complex-function with photopolymerizable compound and photopolymerization initiator. For the sake of high photocuring speed and degree, optimal photo-sensitive materials were selected. In order to match with the light source excitation wavelength and absorb more wider ultraviolet band, combined type of photo-polymerization initiators were employed. With the kinds and dosage of photopolymerization initiator changing, the photocuring speed and quality can be ameliorated. Through studying the UV-visible absorption spectrum and infra-red spectrum of the material , the optical response property of the inner compound can be obtained.
The time-resolved photoelectron spectra of spectrally sensitized cubic AgCl emulsion are detected with microwave
absorption and dielectric spectrum detection technique. The decay process of photoelectron is accelerated and becomes
faster than that of the unsensitized sample since the concentration of interstitial Agi
+ ions is increased when the dye
molecules are adsorbed onto the surface of crystal. The influence of temperature condition on the photoelectron decay
process is obtained. Results show that the dye adsorption degree is varied when the sensitizing temperature differs, then
the decay dynamic changes. The optimal temperature condition is in 450C in which the adsorption of dye has a larger
influence on crystal property and the photoelectron decay is fastest. When lower or higher than this condition, the
adsorption degree is poor or the dye molecules have a tendency to form bigger dye-aggregates, then the variance of interstitial Agi+ ions is less than that in 450°C and causes a slower photoelectron decay process.
The photoelectron decay characteristic of AgCl mircrocrystals, which are adsorbed with the green-sensitive cyanine dye, has been obtained by using microwave absorption and phase-sensitive measurement technique. Combined with the absorption spectra of cubic AgCl emulsion sensitized by green-sensitive cyanine dye, the influence of green-sensitive cyanine dye adsorption at various adsorbing concentration on the surface structure of cubic AgCl microcrystals is investigated. It is found that when the concentration is less than 0.02ml(5.0mg/ml)/40g emulsion, the dye J-aggregate is not formed on the surface of silver chloride microcrystals, the surface of AgCl is decorated by the dye, the dye takes place shallow electron trap effect; when the sensitive concentration is more than 0.2ml (5.0mg/ml)/40g emulsion, the dye J-aggregate is formed on the surface of silver chloride microcrystals, the Agi+ of AgCl microcrystal surface is increased, the dye takes place the deep electron trap effect
There will be large numbers of carriers coming into being in the interior of silver chloride microcrystals when illumination acts on it. Microwave absorption and dielectric spectrum detection technology with high temporal resolution (1ns) can detect instantaneous decay process of photoelectrons. In this work, the photoelectron decay action of spectral sensitized silver chloride emulsion is measured by microwave absorption and dielectric spectrum detection technology. By analyzing the measured results, it is found that when plentiful dye adsorb on silver chloride microcrystals film, the photoelectron decay of silver chloride emulsion becomes faster than that of pure emulsion. However it is not that the more the dye is adsorbed, the faster the photoelectron decay will be. When the adsorbed dye reaches a certain level, the photoelectron decay becomes slower than the fastest instance. Combining with photoelectron decay kinetics theory it is found that the above results are induced by two kinds of effect from dye adsorption.
Microcapsule material can be controlled to perform various functions for its unique characteristics by
changing certain environmental conditions, such as mechanical, chemical or electrical factors. In
information-recording field, the applications of pressure-sensitive and heat-sensitive microcapsules
have matured sufficiently. But limited by the size of thermal or pressure print head, these kinds of
microcapsules can not realize the high image resolution printing. Based on microcapsule, as well as
photo-responsive and heat-sensitive techniques, the photo-heat sensitive microcapsule can react quickly
to very wavelength by photo-curing and can record the optical information of high-resolution. In this
paper, a novel photo-heat sensitive microcapsule has been synthesized by interfacial polymerization
method. Some factors that affected the size and distribution of microcapsule had been considered, the
relationship between particle size distribution and the shearing speed was mainly discussed. In order to
eliminate the photographic fog, the microencapsulation of developer was adopted in experiment.
Optical response property of the photo-heat sensitive microcapsule was studied. The relationship curve
between image density and exposing time was obtained. This new generation high resolution recording
material can be used in optically controlled digital image reproduction field.
Continuous and semipermeable films or coatings have been receiving a great of fundamental scientific and practical
interest, for improving the function-control properties of encapsulated compounds. In this paper, the polyurea film is
synthesized with the interface polymerization method. To investigate the penetrability property, color-form function
compound is encapsulated. The shape and diameter of the microcapsules are studied and microcapsules with size smaller
than 1µm have been prepared, which can act as basic function cell with excellent smart property to response the outside
thermal stimuli. From TG results, the polyurea microcapsule has high thermal stability. The penetrability property of the
microcapsule system is obtained. Color density against heat-processing time and developing temperature confirms that
the penetrability variety is ascribed to thermal condition. The penetrability shows a normally linear trend under given
thermal-processing condition, while the penetrability process would achieve to stable state after long penetrating time,
though at different initial thermal condition the penetrability velocity is different.
The characteristic of semi-conduct will be influenced, when environmental conditions act on it. Silver halide
microcrystals, kind of false compositive microcrystals, is a kind of typical photoelectric material. In this work, the silver
chloride microcrystals adsorbing dye are excited by laser with different wavelengths, the photoelectron signals of which
are measured by microwave adsorption dielectric spectrum equipment with a high time resolution (1ns). It is found that
the photoelectron decay time of pure emulsion excited by 355nm and 532nm laser is respective 109ns and 47ns; The
photoelectron decay time of sensitized emulsion with sensitization concentration of 4mg/40g is respective 83ns and 23ns
when it is excited by 355nm and 532nm laser; The photoelectron decay time of sensitized emulsion with sensitization
concentration of 8mg/40g is respective 76ns and 12ns when it is excited by 355nm and 532nm laser. The results show
that the change extent of photoelectron decay are not the same when silver chloride emulsion is excited by laser with
different wavelengths, so the sensitive effect of adsorbed dye is different under different exposal wavelengths.
Microwave absorption and dielectric spectrum detection technology, with high time resolution (less than 1ns), was used for non-contact measurement of electron property in solid materials. In this paper, the photoelectron decay time-resolved spectra of free electrons in cubic AgCl emulsion sensitized by different concentrations of green-sensitive cyanine dye were measured by dielectric spectrum equipment. At the same time the absorption spectra were obtained by spectrophotometer. Experiments show that when the sensitive concentration is less than 0.02ml(5.0mg/ml)/40g emulsion, the dye J-aggregate is not formed on the surface of silver chloride microcrystals; The photoelectron decay is slower than that of pure cubic AgCl emulsion. when the sensitive concentration is more than 0.2ml (5.0mg/ml)/40g emulsion, the dye J-aggregate is formed on the surface of silver chloride microcrystals; compared to the M-state of dye, the maximal absorption peak of J-aggregate is shifted to longer wavelength about 50nm. The photoelectron decay is faster than that of pure cubic AgCl emulsion.
The temporal actions of free photoelectrons and shallow trapped photoelectrons in the AgBrI-T grain emulsion were obtained with the microwave absorption and dielectric spectrum technique at the same time. The results indicate that the electron trap effect of sensitization center changes from shallow to deep with the increase of sensitization time. When the function of chemical sensitization center is shallow electron trap effect, the decay of electron is slower and the decay time and lifetime of the photoelectron in sensitized sample are longer than that in unsensitized sample because the sensitization center holds back the recombination between the electron and the hole. When the function of chemical sensitization center is deep electron trap effect, the decay of electron is quicker and the decay time and lifetime of the photoelectron in sensitized sample are shorter than that in unsensitized sample because the sensitization center deeply traps the electrons. The optimal sensitization time is gained according to the relationship between decay time of photoelectron and sensitization time.
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