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A CO2 sensor made of nano crystalline CuO–BaTiO3 semiconductor, which has a giant capacitance effect, is designed based on the principle of the physical effect in the nano cluster. After an experimental investigation of its microstructure, the correlation between the quantum size effect and the giant capacitance effect is suggested. The characteristic physical quantities relating to the giant capacitance effect of the sensor are studied systematically with the aid of a gas detector. The quantum size effect is introduced as an interpretation for the mechanism of the giant capacitance effect and a model is proposed for describing the giant capacitance effect of the sensor.

The hot deformation behavior of ZA27 alloy was investigated in the temperature range of 473-523 K with the strain rates in the range of 0.01-5 s -1 and the height reduction of 60 % on Gleeble-1500 thermo mechanical simulator. Based on the experimental results, constitutive equations incorporating the effects of temperature, strain rate, and strain have been developed to model the hot deformation behavior of ZA27 alloy. Material constants, a, n, ln A, and activation energy Q in the constitutive equations were calculated as a function of strain. The results showed that the stress-strain curves of ZA27 alloy predicted by the constitutive equations are in good agreement with experimental results, which validates the efficiency of the constitutive equations in describing the hot deformation behavior of the material.

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In this study, crushed metal enrichment (CME) originated from waste printed circuit boards was treated by a novel oxidizing alkali-salt fusion process to separate and recover metal values. The fusion system consists of CME, alkaline medium and oxidant. Based on former studies, mixture of NaOH and Na2CO3 was selected as alkaline medium, while NaNO3 as the oxidant. Parameters and factors of the fusion process were studied systematically, and the optimized conditions were determined as CME/Na2CO3/NaOH/NaNO3 mass ratio of 1:1:3:3, fusion temperature of 600°C, and fusion time of 40 min. Under these conditions, 84.55% of Sn, 73.97% of Pb, 95.22% of Al and 78.87% of Zn were transferred into solution, while over 99.51% of Cu and all precious metals were enriched in the residue.