- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Quasi-continuous-wave laser surface melting of aluminium alloy: Precipitate morphology, solute segregation and corrosion resistance
摘要： A quasi-continuous wave laser surface melting is performed on 2219 aluminium alloy to improve the corrosion resistance. The fast cooling rate and the multi-directional solidification behavior of the process transform large and long-chained constituent particles into fine and isolated circular precipitates with alleviated solute segregation. The improved corrosion resistance is due to formation of low-flaw-density passive film, reduction of the driving force for corrosion and improvement of the re-passivation capability of the modified surface. The large and long-chained constituent particles are the preferred sites for corrosion initiation and propagation.
关键词： C: Segregation,B: Polarization,C: Pitting corrosion,A: Aluminium,B: EPMA
更新于2025-11-28 14:24:20
-
Plasma Diagnostic by Optical Emission Spectroscopy on Dolomite and Cross-Validation Using Scanning Electron Microscopy Coupled with Energy Dispersive X-ray Spectroscopy and Electron Probe Micro-Analysis
摘要： Dolomite [CaMg(CO3)2] is an important carbonate mineral mainly composed of calcium magnesium carbonate. The correct determination of magnesium content in carbonate rocks is important for accessing its suitability for different applications; however, presence of different phases with varying magnesium contents makes their analysis difficult. In the present work, a natural carbonate mineral dolomite is analyzed qualitatively and quantitatively using laser-induced breakdown spectroscopy along with X-ray diffraction, scanning electron microscopy coupled with energy dispersive spectroscopy and electron-probe microanalysis. The optical emission spectra recorded in 200–720 nm wavelength region revealed presence of emission lines for Ca, Mg, Al, Sr, and Na with varying intensities. We used two different techniques, that is, Boltzmann plot and Saha–Boltzmann plot methods to calculate the plasma temperature, and an average value of 4500 ± 450 K was deduced.The Stark broadening line profile method was exploited to calculate the electron number density using calcium and magnesium lines which resulted in 2.39 × 1017 cm–3. The quantitative compositional analysis was carried out using calibration-free laser-induced breakdown spectroscopy method for which the local thermodynamic equilibrium and optically thin plasma conditions were satisfied.The composition for dolomite major constituents calcium and magnesium were estimated as 68.58 and 31.41%, respectively.The results demonstrated the LIBS, EDS, and EPMA ability as an effective, powerful and complementary analytical techniques for the elemental composition analysis of carbonate minerals.
关键词： magnesium,calibration-free laser-induced breakdown spectroscopy,EPMA,plasma diagnostic techniques,dolomite,EDS
更新于2025-09-19 17:13:59
-
Impurities in large scale produced Nd-doped phosphate laser glasses. II. Pt ion and Pt inclusion
摘要： Platinum is a special kind of impurity in Nd-doped phosphate laser glasses. Firstly, its presence in the glass depends on the production processes, rather than the purity of the raw materials used. Secondly, there coexist Pt ion and Pt inclusion in the glass, which one is the oxidized and the other is the reduced. The detection for these two kinds of Pt impurities in the large-scale produced Nd-doped phosphate laser glasses can re?ect the control level and stability of the processes. To determine more accurately the content of Pt ion in the glass, a hemi-cyanine dye, instead of SnCl2 previously used, is utilized to color Pt ion solution by dissolving the glass. On the basis of such a new hemi-cyanine spectrophotometric analysis, the factor of proportionality between Pt ion content and its absorption coe?cient at 400 nm is determined and discussed. To avoid the interference from other cations in the multi-cation solution by dissolving the glass, when doing ICP-MS analysis for Pt, a magnetic poly-ionic liquid is synthesized successfully by bonding an ionic liquid to nano-Fe3O4 particles covered by C. Such a new magnetic poly-ionic liquid can adsorb Pt ions with a better selection. The element distribution of Pt, O and P for di?erently sized Pt inclusions in the glass is analyzed by EPMA.
关键词： Pt ion,Pt inclusion,Selective adsorption for Pt ion,EPMA,Spectrophotometry,Nd-Doped phosphate laser glass
更新于2025-09-12 10:27:22
-
[IEEE 2018 International Conference on Advances in Computing, Communications and Informatics (ICACCI) - Bangalore, India (2018.9.19-2018.9.22)] 2018 International Conference on Advances in Computing, Communications and Informatics (ICACCI) - Design and Analysis of Circularly Polarized Defected Ground Elliptical Patch Antenna for Long Term Evolution (LTE) and 4G Wireless Applications
摘要： In this article the strategy and analysis of a defected ground stacked elliptical patch microstrip antenna (EPMA) is presented for circular polarization (CP). This antenna gives an impedance bandwidth of 44.0% with respect to resonant frequency 1.98GHz, which is eight times greater in comparision to conventional elliptical patch microstrip antenna (EPMA) along with axial ratio bandwidth of 5.5% with reverence to frequency 1.98GHz. The antenna is studied on a Flame Retardant (FR-4) substrate having substrate permittivity 4.4 and thickness 1.59mm. The CP behaviour is observed by truncating the conventional elliptical patch and inserting slots. A square slot is also etched in ground plane at an angle of 45 degrees with respect to horizontal axis. This antenna design having a dimension of ground plane 35.0×32.0 mm2. To achieve the higher impedance bandwidth, the technique of multilayer stacked of patch is used. The over all height of antenna is 9.18mm. This antenna can be used in Long Term Evolution (LTE) and 4G Wireless Applications.
关键词： circularly polarized (CP) antenna,Elliptical microstrip antenna (EPMA),impedance bandwidth (IBW),defected ground (DG) technique,multi-layered stacked structure,axial ratio bandwidth (ARBW)
更新于2025-09-09 09:28:46