检索结果-南通市图书馆

Charateristics of a helical axial flow co2 laser

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of lasers 1993年第6期 19-24页

作者： l-yung Fu, Chin-chiang Liu, Hai-pei Liu (Institute of Optical Science, Central University, Taiwan)

A novel co2laser tube which forms a helical axial gas flow is designed. The influences of such a flow on the output laser beam is discussed.

关键词： helical axial flow co2 laser

Resonator and Beam Quality of the Multi-Channel Spiral Flow co2 laser with Round-Metal-Resonator

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Resonator and Beam Quality of the Multi-Channel Spiral Flow ...

Imaging and ex-vivo tissue analysis by Infrared co2 laser Assisted Rapid Evaporative Ionisation MS – towards an integrated MS-based tissue identification system

作者： Wei GONG Solid-state Device Department (IPE), Wuhan Research Institute of Posts and Telecommunications Wuhan, Hubei, 430074, P.R.China Tel: +86-27-87691409 E-mail: datou@*** Zaiguang LI Desheng XU~* State Key Laboratory of laser Technology Huazhong University of Science and Technology (HUST) Wuhan, Hubei, P. R. China 430074

For developing a new laser for laser citting, which has the advantage of good beam quality, small size and low cost, we have proposed a round-metal-resonator co laser with blow-in discharge and spiral flow. In this paper, investigations have been made on the resonator and beam quality of this laser. At first the ideal of the new laser is introduced in this paper. And secondly, the new structure for carbon dioxide laser is explained. Thirdly, investigations have been made on the resonator and the output beam quality of the carbon dioxide laser. The resonator parameters arc determined by the matrix optics calculations and by considering the size of experimental structure and the basic design principles of resonator. The output laser intensity spacial distribution of the laser resonator with gain spacial distribution inside is obtained by solving the diffraction integral equations through iteration method. The results indicate that from the new structure laser, the quasi-fundamental mode laser beam can be obtaed with a higher efficiency. The ideas to improve the gain distribution in the lasing channel, and than the quality of the mode of the output beam are arisen from these calculations.

关键词： co2 laser round-metal-resonator multi-channel spiral flow resonator beam quality

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Imaging and ex-vivo tissue analysis by Infrared CO2 Laser As...

co_2 laser-micro plasma arc hybrid welding for galvanized steel sheets

2018年中国质谱学术大会（CMSC2018）

作者： Haixing Wang Zoltan Takats Key Laboratory of Anesthesiology of Zhejiang Province Department of AnesthesiologyThe Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University Imperial college

As a direct combination of surgical diathermy and MS analysis of the electrosurgical aerosol, rapid evaporative ionization mass spectrometry(REIMS) is a novel ambient ionization method. Surgical REIMS(or iknife) has been demonstrated to provide real-time tissue identification during surgical interventions with a strong potential for margin control in oncological surgery and applied for food chemistry research already.[1-3] One of the remaining problems for the surgical REIMS is the construction of histologically annotated spectral databases, which are essential for pattern recognition-driven identification. Due to the destructive nature of the electrosurgical REIMS system, a tumor specimen gives limited data points and the histological identification of already evaporated cells is not straightforward. As an alternative, a infrared co2 laser-based system was devised, which is capable of MS imaging and ex-vivo analysis of biological tissues. The setup is described, and optimization of the laser parameters is presented. REIMS analysis of the aerosol formed by laser ablation of tissue shows similar spectral characteristics to those acquired by the electrosurgery-REIMS system, with the data dominated by signals corresponding to complex lipids. Imaging of biological tissue with 100 μm resolution is demonstrated and the technique is then applied to human breast tissue samples. In contrast to the destructive nature of electrosurgical REIMS which limits the amount of data collected from a sample and makes histological identification challenging, laser REIMS imaging allows spectral data and histological information to be easily matched. Imaging data are collected for healthy and cancerous human breast tissue and are used to construct a histologically annotated spectral database, with excellent classification accuracy for real-time analysis.

关键词： rapid evaporative ionization mass spectrometry (REIMS) iknife MS imaging co2 laser tissue identification

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 47-53页

作者： C.H.KIM Y.N.AHN J.H.KIM Advance Welding & Joining Research Group Korea Institute of Industrial Technology Incheon 406-840 South Korea

A laser lap welding process for zinc-coated steel has a well-known unsolved problem-porosity formation. The boiling temperature of coated zinc is lower than the melting temperature of the base metal, which is steel. In the autogenous laser welding, the zinc vapor generates from the lapped surfaces expels the molten pool and the expulsion causes numerous weld defects, such as spatters and blow holes on the weld surface and porosity inside the welds. The laser-arc hybrid welding was suggested as an alternative method for the laser lap welding because the arc can preheat or post-beat the weldment according to the arrangement of the laser beam and the arc. co2 laser-micro plasma hybrid welding was applied to the lap welding of zinc-coated steel with zero-gap. The relationships among the weld quality and process parameters of the laser-arc arrangement, and the laser-arc interspacing distance and arc current were investigated using a full-factorial experimental design. The effect of laser-arc arrangement is dominant because the leading plasma arc partially melts the upper steel sheets and vaporizes or oxidizes the coated zinc on the lapped surfaces. compared with the result from the laser-TIG hybrid welding, the heat input from arc can be reduced by 40%.

关键词： galvanized steel co2 laser micro plasma hybrid welding

co_2 laser collective Thomson Scattering Diagnostics on the HT-7 Tokamak

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2004年第6期6卷 2526-2530页

作者：李亚东李建刚毛剑珊 Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 China

A CW co2 laser collective Thomson scattering diagnostics was developed to measure plasma density fluctuations on the HT-7 tokamak. The design and construction of co2 laser scattering apparatus is described. The laser source is a continuous-wave co2 laser with a cavity length of 1.9 m and a power output of about 10 W at 10.6 μm. The k-resolution of the system is △k ≈ 3.2 cm-1. The preliminary data from the diagnostic is presented.

关键词： collective scattering density fluctuation co2 laser

Spectral Efficiency of Extreme Ultraviolet Emission from co_2 laser-Produced Tin Plasma Using a Grazing Incidence Flat-Field Spectrograph

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2013年第5期15卷 435-438页

作者：吴涛王新兵王少义 Wuhan National Laboratory for Optoelectronics School of Optoelectronic Science and Engineering Huazhong University of Science and Technology School of Science Wuhan Institute of Technology

A grazing incidence flat-field spectrograph using a concave grating was constructed to measure extreme ultraviolet （EUV） emission from a co 2 laser-produced tin plasma throughout the wavelength region of 5 nm to 20 nm for lithography. Spectral efficiency of the EUV emission around 13.5 nm from plate, cavity, and thin foil tin targets was studied. By translating the focusing lens along the laser axis, the dependence of EUV spectra on the amount of defocus was investigated. The results showed that the spectral efficiency was higher for the cavity target in comparison to the plate or foil target, while it decreased with an increase in the defocus distance. The source＇s spectra and the EUV emission intensity normalized to the incident pulse energy at 45 from the target normal were characterized for the in-band （2% of bandwidth） region as a function of laser energy spanning from 46 mJ to 600 mJ for the pure tin plate target. The energy normalized EUV emission was found to increase with the increasing incident pulse energy. It reached the optimum value for the laser energy of around 343 mJ, after which it dropped rapidly.

关键词： laser-produced plasma extreme ultraviolet (EUV) emission co2 laser spec-tral efficiency EUV lithography

CALCULATION OF INFRARED OPTICAL coNSTANTS FOR co_2 laser HOLLOW WAVEGUIDE MATERIALS

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 1996年第2期11卷 58-66页

作者：刘继翔韩建军赵修建 Wuhan Univ of Technology Wuhan China

A simple method was deduced for calculat-ing optical constant, optical loss and transmittance per meter of hollow-core optical fiber using data analysis method, ge-ometerical optical and electromagnetic theory. The method was used to study the Na2O-ZnO-GeO2-SiO2-PbO and Sb2O3 sysem. The glasses have nrcore diameter ao is 0. 5mm, the hollow waveguides of the Sb2O3-containing . glass is predicted with minimum loss of 0. 8 dB/m at 940cm-1

关键词： co2 laser Hollow waveguides In- frared optical constants

Output mode characteristics of an in-phase locked gain waveguide array co_2 laser

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2011年第8期20卷 222-226页

作者：沙鹏飞辛建国周英刘正帆 School of Optoelectronics Beijing Institute of Technology

In this paper, experimental and theoretical studies of the output mode characteristics of an in-phase locked gain waveguide array co2 laser are reported. The experimental results of the optical oscillation mode frequency, the far-field intensity distribution and the burnt pattern of the sliced waveguide array laser are obtained. A revised mode expression of the rectangle waveguide, which is suited for this waveguide array co2 laser, is proposed. The theoretical simulation results based on the revised mode expression are shown to be in good agreement with the experimental results.

关键词： waveguide array phase coupling co2 laser

Effect of co_2 laser sclerectomy with iridectomy on ocular hypertension in rabbits

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2011年第1期4卷 30-32页

作者： Zhi-Xiao Xue 1,3,Ying-Xin Li 2,3,Yan-Shan Xu 4,Jiu-Min Yang 1 1 laser Medicine Laboratory of Tianjin Medical University,Tianjin 300070,China 2 laser Medicine Laboratory,Biomedical Engineering Institute of Chinese Academy of Medical Sciences & Peking Union Medical college,Tianjin 300192,China 3 laser Medicine Technology Engineering Center of Tianjin,Tianjin 300192,China 4 Eye Center of Tianjin Medical University,Tianjin 300384,China laser Medicine Laboratory of Tianjin Medical University Tianjin 300070 China.

AIM:To evaluate the efficiency and safety of an optimized co2 laser glaucoma surgery system for laser sclerectomy with ***:Rabbit trials were performed to evaluate the efficiency and ***:IOP was significantly decreased in laser group compared with trabeculectomy group(Pconfirmed fewer complications and better effects were found in laser ***:co2 laser sclerectomy with iridectomy is effective and safe in terms of IOP lowering.

关键词： co2 laser glaucoma sclerectomy with irid-ectomy intraocular pressure histopathological examination