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We investigated the effect and underlying mechanism of postharvest treatment with 0.5 mmol/L melatonin (MT) treatment 1 h on chilling injury (CI) and ripening of ‘Guifei’ mango fruits during 4 days of shelf life at 25 ℃ after refrigeration at 4 ℃ for 28 days. The results showed that MT treatment markedly decreased CI and enhanced soluble solids content (SSC), respiration rate and ethylene production, while accelerating the decline in hue value and firmness of chilled mango fruits. Compared with the control group, MT treatment promoted the increase in the contents of water-soluble pectin (WSP) and chelate-soluble pectin (CSP) and the activities of polygalacturonase, β-galactosidase and endo-1,4-β-D-glucanase and accelerated the decrease in pectin methylesterase activity, thereby leading to cell wall degradation and fruit softening. Compared with the control group, higher activities of 1-aminocyclopropane-1-carboxylic acid synthase (ACS) and 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) and the expressions of their encoding genes (MiACS and MiACO) were observed in MT-treated fruits. Moreover, MT up-regulated the expression of MiETR1, MiERS1, MiERF1, MiEIN2, MiCBF1 and MiICE1 while down-regulating the expression of MiCTR1. These results indicated that MT treatment could promote the restoration of ripening and reduce CI in mango fruits during shelf life after storage at low temperature.

MnO2/MCM-41 composite was prepared by one-pot method to investigate its removal of Sr2+ from radioactive wastewater. The prepared composite were characterized by SEM，BET，FT-IR. The effects of parameters such as mass ratio，pH，adsorption time and competing ion effect of MnO2 and MCM-41 on the adsorption test were investigated. The results showed that the composite adsorbent could rapidly adsorb Sr2+ in water and reached the adsorption equilibrium in 120 min with the maximum adsorption capacity of 85.46 mg/g. The composite adsorbent had the highest adsorption capacity when the mass ratio of MnO2 and MCM-41 was 4∶1 ，and the composite adsorbent had high adsorption performance in the range of pH 4-9. In addition，the composite adsorbent maintained good adsorption capacity in the presence of Na+，K+，Mg2+ and Ca2+，and the inhibited adsorption capacity followed the order of Na+< K+< Mg2+< Ca2+. The adsorption kinetic data analysis of the pseudo-secondary model fit the adsorption data better than the pseudo-first-order model，indicating that chemisorption dominated the adsorption process. The novel MnO2/MCM-41 composite prepared for the removal of Sr2+ from radioactive wastewater had the advantages of rapid adsorption，high adsorption capacity，selectivity，and the ability to be prepared on a large scale，which made it promising to play an important role in the field of Sr2+ containing radioactive wastewater removal.

The purpose of this study was to explore the effect of treatment with dielectric barrier discharge (DBD) plasma followed by complexation with resveratrol on the physicochemical properties and digestibility of green banana starch. The results showed that DBD plasma treatment improved the complexation between banana starch and resveratrol. Compared with unmodified banana starch, the solubility, retrogradation properties, oil-holding capacity, gelatinization temperature (the onset gelatinization temperature (To), peak gelatinization temperature (Tp) and conclusion gelatinization temperature (Tc) increased from 64.10, 71.14 and 73.92 ℃ to 70.18, 75.79 and 82.53 ℃, respectively) and digestibility of the complex were significantly improved, while the swelling power and freeze-thaw stability were reduced. Scanning electron microscopy (SEM) showed that DBD plasma treatment produced more starch fragments and etched the starch surface. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) showed that resveratrol combined with banana starch through CH-π bond, which made the structure of the complex more compact and orderly, forming a non V-type inclusion complex with high crystallinity. Therefore, plasma treatment and then complexation with polyphenols can improve the processing properties of banana starch, which will contribute to the development of new health foods.

The side wall interference and disturbance reflection from the front end wall of a sealed chamber in an extremely low wind speed calibration facility operated by driving the probe in motion might have influence on the flow field inside the chamber,thus affecting the calibration accuracy.The moving overlapping grid technique is used in solving the URANS equations simulating the flow field in the chamber to investigate the effects of side-wall interference and the disturbance wave reflection from the front(upstream)end wall on the interior flow field and calibration.The flow fields in the cases with and without side walls are computed and compared.For the front end wall reflection of the strut rod disturbance,the boundary conditions with and without front end wall are used respectively in computing the flow field in the chamber,and the computed flow fields in the two cases are compared at several instants,respectively.The computed results show that the effects of velocity deviations caused by the wall interference and the front end wall reflection of disturbance on calibration accuracy are in an acceptable range.

This work summarizes the application of gas fumigation technology in postharvest fruit quality management and related biochemical mechanisms in recent years. Gas fumigants mainly include SO2, ClO2, ozone, NO, CO, 1-MCP, essential oils, H2S and ethanol. This work indicated that gas fumigation preservatives can effectively improve postharvest fruit quality, which is mainly manifested in delaying senescence, inhibiting browning, controlling disease and alleviating chilling injury. Gas preservatives are mainly involved in postharvest fruit quality control in the roles of antifungal agent, anti-browning agent, redox agent, ethylene inhibitors, elicitor and pesticide remover. Different gas preservatives have different roles, but most of them have multiple roles at the same time in postharvest fruit quality management. In addition, the role of some gas preservatives with direct antifungal activity in the control of postharvest fruit diseases can also activate defense systems to improve fruit resistance. It should be noted that some gas fumigation treatments with slow-release effects have been developed recently, which may allow gas fumigation gases to perform better. Moreover, some gas fumigants can cause irrational side effects on the fruit and some combined treatments need to be found to counteract such side effects. [ABSTRACT FROM AUTHOR]

Radioactive waste generated in nuclear energy utilization poses great environmental risks, and the safe disposal technology has become a hot research topic in the field of nuclear environmental security. Immobilization is a common radioactive waste disposal technique, and the leaching resistance of the solidified body is the key to safe disposal. In the study, metakaolin was used as a raw material to solidify strontium, a common nuclide in radioactive waste streams, and then conducted leaching resistance tests. Using control variables, the experiments were used to investigate the effects of adsorption pretreatment prior to solidifying, solidifying with and without the addition of adsorbent on the effect of immobilization. The leaching resistance of the solidified bodies were investigated in three leaching environments: 25℃ deionized water, pH=1 sulfuric acid solution, and 5%wt magnesium sulfate solution during the 42d test cycle. The results showed that both leaching rate and cumulative leaching fraction of the 42d samples for the leaching resistance of radioactive waste immobilization under the environment of deionized water at 25℃. For the three leaching conditions, the adsorption pretreatment with (4:1)MnO2/HMSS before solidifying or the addition of (4:1)MnO2/HMSS while solidifying could effectively improve the leaching resistance of solidified body, and the former was more effective. The results of this study can provide reference for the disposal of strontium-contanining radioactive waste.