Laser remelting on the surface of Cr12 steel was performed by CO2 Laser. Microstructure of the laser remelting layer is studied by optical microscopy, SEM. Wear resistance of Cr12 steel before and after laser surface remelting is studied. The reasons for enhancing wear resistance is discussed. The experimental results show that the super-refined microstructure with dendritic A′ and interdendritically laminal transformed ledeburite (A′+(Cr?Fe)7C3) were formed in the remelting layer. Super-refined microstructure and plenty of austenite after laser surface remelting and formation of dislocation cluster during wear reinforce wear resistance。

The distortional fields of interface-U-field and V-field-have been obtained after the mechanics property for the geometric distortion of interface of cracked zinc alloy ZAS35/carbon steel is analyzed by means of a laser moire interferometry. The optimum cast preheating temperature has been decided in the light of the experiment of shear strength. After the microstructure of interface of bimetal composite of zinc alloy ZAS35/carbon steel is analyzed and studied with a X ray diffraction and an electronic scanning mirror (ESM), the phase component of metallurgical bond of interface of zinc alloy ZAS35/carbon steel has been gained, and the results of interface scan of distribution of elements Fe/Zn have been obtained with the dip coating temperature of 700(C. The above working theory, the experimental technology and its results will be introduced in this paper, and its results will be analyzed.

This assay makes further inquiries to technological treatments of laser cutting for sheet on the basis of current processes of laser cutting, which contains setting up a line of lead-in and lead-out , arranging auxiliary cutting path reasonably , optimal torch path determination , optimal nesting and selecting the process parameters of laser cutting. Make use of computer in laser cutting to realize computer aided process planning (CAPP).

The technology and joint properties of TC1 titanium alloy using CO 2 laser welding were investigated. The problem of melting pool protection was resolved by designing a rear-cover and a special clamp. Joints with good quality were obtained, which had no pore, crack and surface-oxidation. In addition, the welding speed could reach 3m/min with the plate of 1.5mm thickness being penetrated. The profile of joint cross sections was "sandglass". Through analyses of the microstructure and mechanical property, it has bee found that the weld with the relatively coarse microstructure still has good performances.

Laser remelting of thin plate, made of 5Cr4Mo3SiMnVAl(012Al) die steel and Cr12MoV die steel with thickness of 0.3mm to 2.0mm, was carried out by the use of pulsed Nd:YAG laser. The effects of technical parameters such as pulsed width and pulsed frequency, materials and materials thickness on the geometric characteristics of laser remelting zone were studied. One-dimensional (1D) analytical model was also used to calculate the depth of laser remelting. The results show that the width and depth of laser remelting zone increases with the increase of pulsed width or the decrease of pulsed frequency, and the width and depth of laser remelting zone of Cr12MoV die steel is bigger than that of 012Al die steel, and the width of laser remelting zone increases and the depth of laser remelting zone decreases with the increase of materials thickness, and the 1D model is useful for the calculation of laser remelting depth. The main reason is the differences of laser remelting technical parameters, the dissipated heat case of materials and the thermophysical properties of materials.

On the basis of LohmannⅢ Computer-generated hologram (CGH), this paper introduces encoding theory and making technology about two-channel CGH. The simulation results of CGH reconstruction are given. The method of computer simulation for CGH provides an effective way to evaluate the CGH encoding schemes and reconstruction image quality.

Clear photograph of laser holographic interferometry fringes is a basic work for measuring physics factors. In this paper, eliminating background interference and increasing contrast of photograph have been investigated and discussed by computer program technique. The fringes of interferometry fringes are fined and the information can be easily read and distinguished.

A new method of making embossed circular-viewing rainbow hologram for two-dimensional object is presented in this paper. Twice exposures, and the relative position for slit and object rotating 90°angle when the second exposure. We can observe reconstructed images in any direction rotating embossed hologram by white light. This method more advance making technology of embossed hologram in augment visual angle. This method is very simple and practical.

the ultraviolet absorption spectra and fluorescence spectra for acetic acid solution under the wavelength of 254nm (Δλ1/2(4nm) UV light excitation are measured by a grating spectrometer. And their emitting mechanism and spectral characteristic are investigated. The experimental results and theoretic analyzing about it are presented in this paper. It shows that the acetic acid solution emitting fluorescence quantum yield efficiency under 254nm excitation may reach above 50%, the fluorescence result from the -C=O- fluorophores in acetic acid molecule, the fluorescence quantum yield of acetic acid solution changes as the concentration alternates. Investigation on the ultraviolet absorption spectra and fluorescence spectra and their characteristics will contribute to study other organic macromolecule fluorescence spectra when acetic acid serves as solute and hydrolysis catalyst.

This paper reports the experimental study on the pulse duration stability of stimulated Brillouin scattering in cyclohexane pumped with XeCl eximer laser. While the pulse compression ratio is 1.43, the pulse duration stability of stimulated Brillouin scattering with 4.86% is obtained, which is prior to the pulse duration stability of the pump beam.

The effects of the coupling with fiber and flange on the laser power transfer are experimentally studied. It is concluded that the coupling loss of the flange and tie-ins of fiber will result in a significant loss of laser power, which will directly influence the ignition performance of the laser-based firing systems.

The corn(Zea Mays L.) seed was irradiated by He-Ne laser, of which the power densities were 2.83mW/mm 2, 3.95mW/mm 2 respectively and the corresponding irradiating times last 5s, 50s, 500s respectively. The samples were collected randomly at the stage of two leaves and three leaves seedlings respectively. The activities of α-amylase and phosphorylase were studied by the means of colorimetric method. It could analyse the α-amylase isoenzyme spectra by Polyarcrylamide Gel Electrophoresis (PAGE). The results show that both the activities of α-amylase and phosphorylase of treatment groups are higher than the control, α-amylase isoenzyme spectra are varied and new spectra bands present. The experiment indicates that the glycometabolism in plant can be influenced by laser irradiation. Furthermore, it shows that there is the best irradiating dosage of He-Ne laser what has the best biological effects on plant.

Objective:To obtain a new therapy of port-wine stain (PWS) with good effect and few side effects.Methods:The Leghorn combs chosen as the model and treated with small dose HpD and variable pulsed 532nm laser were evaluated histologically and ultrastructurally at different time. Results: Biopsies taken immediately after treatment showed that the endothelial cells of the capillaries are markedlyswollen and occlude the vascular lumen with small fragments of destroyed erythrocytes seen intravascularly. Conclusion: The results provide evidence that small dose HpD and variable pulsed 532nm laser can increase the efficacy of treatment in PWS .

There are 343 cases of hemangioma who were treated by pulse laser in our hospital . 308 cases who had follow-up data of them were carried out by means of a retrospective study and statistical analyzed respectively dividing into groups of age and disease.The results show that cure rate and total utility rate of curative effect are relative with age in those patients with strawberry hemangiomas ,who should be treated early,and not in those of naevus flammeus. Strawberry hemangiomas are real tumors and naevus flammeus are vascular malformations.There are differences in vascular endothelial cells. The various results of curative effort may be related with that in different patients.

Purpose: To elvaluate the complication of laser in situ keratomileusis (LASIK) and its prevention and management for early experience.Methods: LASIK was performed on 100 myopia patients (188 eyes).Results:The complications during the operation included thin flap,incomplete flap,free flap,decentral flap,foreign body in the interface and subconjunctival hemorrhage etc.;The main postoperative complications within 3 months were halos,under or overcorrection,decrease in best corrected visual acuity,infection,flap movement, initial regression.Conclusion: Success of LASIK was that doctors should be familiar with surgical technique and could handle operations effectively.And LASIK has high predictbility and stability of outcome, for the initial operations,doctor shoud be care of management of complication and summary of experience.