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With the continuous improvement of pump-driven liquid cooling requirements for electronic devices, the cooling requirements for multiple dispersed units are inevitable, resulting in higher requirements of equal cooling capacity for parallel microchannel evaporators. Because of the existence of negative slope region in the characteristic curve of two phase flow in microchannel sink, the flow excursion will occur. The flow distribution in the parallel microchannel evaporator is simulated with ammonia as the working medium, and the effects of inlet subcooling degree, heat flux and length of connecting pipe on flow characteristic curve in a microchannel evaporator are studied. Besides, the influence of flow excursion on the overall temperature distribution of evaporator, and the influence of heat flux, inlet subcooling degree, and length of connecting pipe on the flow distribution of two parallel evaporators are investigated. The results show that the flow excursion between evaporators does not necessarily deteriorate the heat transfer capacity of the system, and the arrangement of heating flux, inlet and outlet connecting pipes has a great influence on the stability of the parallel evaporator system.

Taking the Mengku-dayecha protein extracted by alkaline extraction and acid precipitation method as the research object, taking the binding capacity of sodium taurocholate as the inspection index, the preparation process of Mengku-dayecha protein hypolipidemic peptides was optimized through single factor experiment and response surface analysis, and the optimal technology was determined. Under the conditions, the enzymatic hydrolysate was evaluated for lipid-lowering activity and amino acid composition analysis. The results showed that the best preparation conditions for Mengku-dayecha protein hypolipidemic peptides were pepsin hydrolysis for 3 h, pH2.1, substrate concentration 2.7%, enzyme substrate ratio 0.3%, and temperature 37 ℃. Under these conditions, the binding capacity of sodium taurocholate was (70.92%±0.12%). The activity evaluation results showed that the tea protein hydrolysate showed good activity in three in vitro evaluation indicators of lipid-lowering activity: The binding capacity of sodium taurocholate (EC50=6.466 mg/mL), the inhibition of pancreatic lipase (IC50=0.310 mg/mL) and the inhibition of cholesterol esterase (IC50=1.557 mg/mL). Amino acid analysis showed that the obtained Mengku-dayecha protein hypolipidemic peptides was rich in essential amino acids (34.35%), hydrophobic amino acids (31.94%) and acidic amino acids (41.06%).

In this study, the effects of laser power on the microstructure and mechanical properties of Inconel 718 formed by SLM were systematically studied. The results show that with the increase in laser power from 285 W to 360 W, the increase in working temperature in the molten pool promoted the evaporation of gas and the vaporization of the low-melting-point alloy components, and the relative density gradually increased from 99.31% to 99.79%. In addition, with the increase in laser energy density, the microstructure gradually coarsened from columnar dendrites to cellular crystals. The nano-hardness of the material decreased with the increase in laser power. The nano-hardness of four groups of samples from 285 W to 360 W decreased form 3.43 GPa to 2.09 GPa, and the elastic modulus decreased form 205.72 GPa to 199.91 GPa. [ABSTRACT FROM AUTHOR]

To characterize the spoilage of tilapia under super-chilled storage, the bacterial profile and odor and volatile compounds were analyzed. Results showed that the shelf life and bacterial profile of tilapia from different sources varied remarkably, with Pseudomonas being the most dominant organism in tilapia under super-chilled storage (−1.5°C). The correlation analysis showed that the volatile compounds from the spoiled samples were closely related to the bacterial profile. Therefore, no volatile compounds or the response of the electronic nose significantly correlated with sensory spoilage although some of them correlated with that of some specific samples. On the other hand, the total volatile basic nitrogen (TVB-N) was significantly correlated with the sensory spoilage of all samples. In conclusion, under super-chilled storage, the volatile compounds in tilapia, except TVB-N, are sample dependent due to the variation of bacterial profile and therefore cannot be used as a spoilage indicator. [ABSTRACT FROM AUTHOR]