Lan Haipeng

An Experimental Study on the Variation of Physical-Chemical Indicators for Korla Fragrant Pear in the Maturation Stage

In order to study the variation rule of the physical-chemical indicators of Korla fragrant pear in the maturation process, and explore the correlation among these indicators, the fruit firmness, chlorophyll content, soluble solids content(SSC) and Vitamin C content were studied. Adopting to the methods of correlational analysis and regression analysis, the indicators mean and the correlation among them were analyzed, the test results were verified by experiments with SPSS and Excel software. To draw the range of physical-chemical parameters of Korla fragrant pear in the mature period are 4.23-7.99 kg/cm2 firmness, 3.17-6.54 mg/100g chlorophyll, 11.54-11.41% SSC, 0.36-0.6 mg/100g Vitamin C, respectively. The fruit hardness and the content of chlorophyll decrease gradually, while SSC and vitamin C content increase with the deepening of the pear mature. The indices means are significant correlation at the level of 0.01. In the process of regression analysis, the optimal fitting was selected and the corresponding mathematical model was established. The determination coefficients were greater than 0.95 of the four indicators. The error of the predicted value and the measured data was less than 3.21% through verification. Therefore, the content of chlorophyll and Vitamin C can be predicted from the fruit firmness and SSC during the maturity of fragrant pear. The research results can provide reference for maturity evaluation and classification of Korla fragrant pear.

Study on Fracture Mechanism of Walnut Shell According to Brittle Fracture Area

In order to improve crushing rate of walnut shell and study the fracture process and mechanism of walnut shell. This paper breaks walnuts shell by mechanical method and uses scanning electron microscope (SEM) to study crack fracture face. Research results show that: 1) According to the difference of microscopic tissues fracture morphology, walnut shells fracture areas can be divided into two regions from inner to outer., The thickness of the outside region is about 2 times more than the thickness of the inside region, 2) using material brittle fracture theory, this paper proposed a hypothesis of walnut shells brittle crack, 3) applying impulse load to more places of walnut can improve the local crushing rate of walnut shell under small deformation, which ensures fully breaking of walnut shell and the integrity of walnut kernel.