HOLE PROFILE AND TUNNELLING EFFECT IN LASER DRILLING

ＨＯＬＥＰＲＯＦＩＬＥＡＮＤＴＵＮＮＥＬＬＩＮＧＥＦＦＥＣＴＩＮＬＡＳＥＲＤＲＩＬＬＩＮＧＨＯＬＥＰＲＯＦＩＬＥＡＮＤＴＵＮＮＥＬＬＩＮＧＥＦＦＥＣＴＩＮＬＡＳＥＲＤＲＩＬＬＩＮＧＪｉａｎｇＣｈｅｎｇｙｕ；ＸｕＪｉｕｈｕａ（ＮａｎｊｉｎｇＵｎｉｖｅｒ...     

LASER SHOCK PROCESSING EXTENDS FATIGUE LIFE OF 2024T62

ＬＡＳＥＲＳＨＯＣＫＰＲＯＣＥＳＳＩＮＧＥＸＴＥＮＤＳＦＡＴＩＧＵＥＬＩＦＥＯＦ２０２４Ｔ６２ＲｅｎＮａｉｆｅｉ，ＣａｉＬａｎ，ＹａｎｇＪｉｃｈａｎｇＪｉａｎｇｓｕＵｎｉｖｅｒｓｉｔｙｏｆＳｃｉｅｎｃｅａｎｄＴｅｃｈｎｏｌｏｇｙＺｈａｎｇＹｏｎｇｋａ...     

STUDY OF THE MECHANISM TO IMPROVE PERFORMANCE OF CARBIDE BLADE BY LASER

ＳＴＵＤＹＯＮＴＨＥＭＥＣＨＡＮＩＳＭＴＯＩＭＰＲＯＶＥＰＥＲＦＯＲＭＡＮＣＥＯＦＣＡＲＢＩＤＥＢＬＡＤＥＢＹＬＡＳＥＲＳＴＵＤＹＯＮＴＨＥＭＥＣＨＡＮＩＳＭＴＯＩＭＰＲＯＶＥＰＥＲＦＯＲＭＡＮＣＥＯＦＣＡＲＢＩＤＥＢＬＡＤＥＢＹＬＡＳＥＲＸｕＺｈｅ...     

RELATIONSHIP BETWEEN PLASMA OPTIC SIGNAL AND PENETRATION DEPTH FOR PARTIAL-PENETRATION LASER WELDING

Through sampling and analyzing of plasma optic signals of 400-600 nm emitted from partial-penetration laser welding processes, how the penetration depth is related to the welding parameter and the plasma optic signal is studied. Under the experimental conditions, the plasma optic signal has good response to variety of the weld penetration, and the signal's RMS value increases with the penetration in a quadratic curve mode. The inherent relation between the plasma optic signal and the penetration depth is also analyzed. It is also found that, between the two common parameters of laser power and welding speed, laser power has more influence on penetration while welding speed has more influence on weld width. The research results provide theoretic and practical bases for penetration real-time monitoring or predicting in partial-penetration laser welding.     

Hybrid (LASER + CNC) process for lubricant groove on linear guides

A novel hybrid process [LASER?+?computer numerical control (CNC) machining] is used to fabricate a linear motion guide. A 20-W pulsed fiber laser and a three-axis CNC machining center were combined to fabricate microscale lubrication grooves on a 5-mm wide linear guide contact surface made of SCM-440H material. Ablation fabrication speed was increased up to 1,000 mm/min (or 16.7 mm/s) with a great ablation quality without any tool wear. The mean values of patterned sizes of lubrication grooves were measured to be between 40 and 80?μm in width and between 150 and 275?μm in depth with a laser pulse repetition of 25 kHz. A specially designed optical device was compact enough to be installed on CNC machine. It was mounted on the CNC spindle and proved to be flexible enough to deliver the laser beam on to the work piece. The microscale ablation quality of the surface was of sufficient quality to be adopted on most linear motion related applications.     

LASER 310微机A/D与D/A系统的设计

一、引言巡回测控系统的模数与数模转换通常由单板机或系统微机组成,前者成本低,但功能较简单,手工汇编费时,而后者成本很高。本文介绍的系统别具一格地选用了廉价的学生计算机LASER 310,结构简单,经济实用。 LASER310,是一种简易的Z80系列微型机,主机内固化了16K扩展BASIC解释程序,用户RAM分4K、8K、18K等三种机型。可配置64K RAM扩展盒,一部磁带机、一部打印机,二个软盘驱动器,还     

FRAGMENTATION ANALYSIS OF OLIGONUCLEOTIDES BY MATRIX-ASSISTED LASER DESORPTION/IONIZATION (MALDI) MASS SPECTROMETRY

CharacterizationofnucleicacidbyMatrix-assistedLaserDesorption/Ionizationmassspec-trometry(MALDI-MS)islimitedtorelativelysmalloligomers(<30-mer).SeveralfactorshavebeenproposedtoinfluenceThecapabilityoftheMALDIanalysisfornucleicacids.Thesefactorsinclude(a)thedesorption/ionizationefficiencyofanalyte,(b)thephysicaldistributionofanalyteinmatrix;and(c)theextentofanalytefragmentation.Asthepolyoligomeraslargeas150nucleotidesinlengthhavebeensuccessfullydetected1andtheanalyticalmassrangeandsensit…     

DUAL-FREQUENCY LASER USING ANISOTROPIC BIREFLECTANCE FILM （1.2～6.0 MHz） AND ITS POLARIZATION CHARACTER

The appropriate bireflectance film series are selected to get the beat-frequency of dual-frequency laser using anisotropic bireflectance film (DLABF) from 1.2 MHz to 6 MHz. The maximum measurement velocity of the interferometer utilizing DLABF can be up to1.8 m/s. Generally the outputs of the DLABF in a transverse magnetic field are two orthogonal micro-elliptical polarized components when DLABF can emit dual-frequency laser. When the laser tube is spun in the magnetic field, the ellipticities of these two components are also changed. In some certain relative angles, the outputs the DLABF are two almost ideally orthogonal linear polarized components. The frequency stabilization of DLABF is also discussed. The maximum variation of the beat-frequency of the stabilized DLABF can be 0.15 kHz within 46 h. As no quarter wave plate (QWP) needed, DLABFs have better thermal stability than longitudinal Zeeman lasers.