C／Cu材料耐磨损设计准则研究中的均匀设计与回归分析

依据均匀设计方法进行C／Cu复合材料的磨损试验设计,不仅大大减少了试验次数,而且使所选试验点都具有“代表性”。用逐步回归分析方法建立了可靠度与载荷、速度的回归方程,为研究C／Cu复合材料的耐磨损设计准则提供了科学、可靠的依据。     

Simultaneous measurement of CO and CO2 at elevated temperatures by diode laser wavelength modulated spectroscopy

One single semiconductor distributed-feedback (DFB) laser is used to demonstrate the possibility of simultaneous measurements of CO and CO₂ at elevated temperatures. Wavelength modulation spectroscopy with second-harmonic detection is used to improve the detection sensitivity and accuracy. The concentrations of CO and CO₂ are determined from the WMS-1-normalized absorption-based WMS-2f signal peak heights of a proper line pair of CO and CO₂ near 6357.814 cm⁻¹ and 6357.312 cm⁻¹, which are selected using some line-selection criterions for the target temperature range of 300–1000 K. The CO and CO₂ concentrations measurements are within 2.86% and 2.69% of the expected values over the tested temperature range 300–1000 K. The minimum detectable concentrations of CO and CO₂ at 1000 K are 250 ppm m and 280 ppm m respectively.