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Conversion among different moisture-binding types of single Hebei wheat kernels during isothermal drying processing at 60 °C was studied by low field nuclear magnetic resonance (LF-NMR), and moisture migration was studied by MRI. Water inside wheat kernels exists in four types: chemically combined water (T21), strong bound water (T22), loosely bound water (T23), and free water (T24). A new method to obtain the contents of different moisture-binding types is forwarded according to the transverse relaxation time distribution curve of dried wheat kernels. Moisture conversion inside wheat kernels during drying occurs mainly through the following mechanisms: high-temperature drives T24 to diffuse to lower moisture areas and transform into other moisture-binding types, and moisture-gradient drives T22 to transform into T24. The drying process can be divided into two stages. Moisture migrates from endosperm to epidermis during drying. As the drying rate of the wheat kernel significantly decreases, the dr...

Ca3 Co4 O9 is a potential high temperature thermoelectric material. We explore the hydrothermal treatment improved sol-gel method to prepare Ca3 Co4 O9 thermoelectric materials. We find that this treatment can increase the thermoelectric performance of the samples compared with the conventional citric acid sol-gel method. We also find the samples prepared by the improved sol-gel method have more uniform grain distribution, better densification, and less voids. At about 1000K, compared with the conventional sol-gel method, the power factor of the samples prepared by improved sol-gel method improves about 168%.