Search

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nonequilibrium fluctuation relation lies at the heart of the quantum thermodynamics. Many previous studies have demonstrated that the heat exchange between a quantum system and a thermal bath initially prepared in their own Gibbs states at different temperatures obeys the famous Jarzynski-Wójcik fluctuation theorem. However, this conclusion is obtained under the assumption of Born-Markovian approximation. In this paper, going beyond the Born-Markovian limitation, we investigate the statistics of quantum heat in an exactly non-Markovian relaxation process described by the well-known Caldeira-Leggett model. It is revealed that the Jarzynski-Wójcik fluctuation theorem breaks down in the strongly non-Markovian regime. Moreover, we find the steady-state quantum heat within the non-Markovian framework can be widely tunable by using the quantum reservoir-engineering technique. These results are sharply contrary to the common Born-Markovian predictions. Our results presented in this paper may update the understanding of the quantum thermodynamics in strongly coupled and low-temperature systems. Moreover, the controllable heat may have some potential applications in improving the performance of a quantum heat engine.

Biochar is widely used in agricultural production practices as a soil conditioner that can be used both alone and jointly with chemical fertilizer. However, there are few studies on the effects of the combined application of biochar and phosphate fertilizer with different particle sizes on soil and plants. In this experiment, pot experiments were used to study the effects of biochar with different particle sizes on soil nutrients, enzyme activity, and Alfalfa nutrient absorption under two phosphorus levels (according to diameter, the biochar was divided into C1:>1 mm and C2:<0.01 mm). This study showed that the combined application of biochar and phosphorus significantly improved soil nutrients, enzyme activity, and Alfalfa nutrient absorption. Among them, the C2 treatment significantly increased the soil available phosphorus content and phosphatase activity ( P <0.05), whereas the C1 treatment had a significant effect on ammonium nitrogen, nitrate nitrogen, urease, and catalase activities ( P <0.05). Moreover, the differences in nutrients and enzymes among biochar treatments with different particle sizes were affected by soil phosphorus levels. At the P0 level, there was no significant difference in ammonium nitrogen and nitrate nitrogen contents between the C1 and C2 treatments. At the P1 level, the contents of NH 4 + -N and NO 3 - -N in the C1 treatment were 24.19% and 18.68% higher than those in the C2 treatment ( P <0.05), but there was no significant difference between the C1 and C2 treatments. Phosphorus addition significantly increased the N and P contents of Alfalfa above ground and in the ground ( P <0.05), but there was no significant effect on the nutrient content of Alfalfa between different particle sizes of biochar. In conclusion, biochar and phosphate fertilizer can be used as an effective means of soil improvement. In addition, when using biochar for soil improvement, the impact of particle size on soil nutrients and soil enzymes should be considered.

To explore the effects of exogenous melatonin on antioxidant capacity and nutrient uptake of plants under drought stress, we used Lolium perenne and Medicago sativa potted seedlings for foliar spraying and root application of 100 μmol·L -1 melatonin, respectively. We measured the biomass, malondialdehyde (MDA) content, relative conductivity, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities, as well as nutrient contents (organic carbon, total nitrogen, total phosphorus) under drought stress. The results showed that the biomass of L. perenne and M. sativa decreased significantly under drought stress, and that external melatonin application could effectively alleviate the inhibitory effect of drought stress on L. perenne and M. sativa . Foliar spray and root application of melatonin under drought stress enhanced L. perenne biomass by 14.5% and 29.6%, and that of M. sativa by 36.6% and 49.1%, respectively. The SOD and POD activities in L. perenne and SOD activity in M. sativa significantly decreased under drought stress, and exogenous melatonin significantly increased SOD, POD and CAT activities in L. perenne and M. sativa , reduced the accumulation of MDA in leaves, caused a significant decrease in the relative conductivity of leaves, and significantly increased antioxidant capacity. Drought stress and exogenous melatonin did not affect organic carbon content of L. perenne and M. sativa. Under drought stress, the contents of N and P in L. perenne leaves and roots and the content of N in M. sativa roots decreased, while the application of melatonin increased the contents of N and P in roots and leaves of L. perenne and M. sativa , indicating that melatonin could regulate the nutrient absorption of L. perenne and M. sativa under drought stress. In conclusion, the melatonin application not only improved the antioxidant capacity of plants, but also regulated nutrient uptake to enhance plant resilience to drought stress. Foliar spraying of melatonin was more effective than root application.

The concentration, potential source and health risks of 16 polycyclic aromatic hydrocarbons (PAHs) in the atmosphere of Dajiuhu, Shennongjia, China, were studied. Polyurethane foam (PUF) Passive air samplers (PAS) were settled. The results indicated that the total concentrations of 16 PAHs in different samples ranged from 6.94 to 184.23 ng·m -3 , with the mean of 30.36 ng·m -3 . The dominant compounds were low rings PAHs, such as Phe, Nap, Pyr, Fla, Flu and Ant. Compared with other regions, the PAHs pollution of Dajiuhu atmosphere was at a low level. Higher PAHs concentrations were detected in nearby Deer farm, Dajiuhu peat area and Dajiuhu Wetland Authority. Higher PAHs concentrations were detected in autumn and winter, whereas lower concentrations were detected in spring and summer. Potential pollution sources of PAHs were investigated by diagnostic ratios and backward trajectory analysis, which indicated that coal and biofuel combustion, vehicle emissions and petroleum were the main sources. PAHs of Dajiuhu in air not only came from local emission, but also originated from Hubei, Henan and Hunan's atmosphere transport for most part and long range transport from northwest direction for small part. Health risks assessment results showed that the annual average concentration of total Benzo(a)pyrene-equivalent carcinogenic potency (∑BaP eq ) was 0.208 ng·m -3 , lower than the value recommended by Ambient Air Quality Standard of China(GB 3095-2012, 1 ng·m -3 ), indicating a low carcinogenic risk for the local residents.

A total of 14 biological samples and 3 water samples were collected from the Qingbang Island. The concentrations of OCPs in the samples were determined by GC-ECD to investigate the distribution, composition, source and potential health risks of these compounds in the study area. The results showed that OCPs were detected in all samples. The detection ratios of OCPs were 100%. Concentrations of HCHs and DDTs ranged from 0.09 ng x g(-1) to 11.51 ng x g(-1) and 0. 02 ng x g(-1) to 56.15 ng x g(-1), respectively. Compared with other regions, the pollution of OCPs in Qingbang Island stayed at a low level. Distribution characteristics of OCPs in halobios from Qingbang Island indicated that changes in the upwelling and fronts were the main factors that affected the distribution of OCPs. Source analysis showed that HCHs and DDTs in halobios were mainly originated from the external. In addition, OCPs residues were far below the National Food Safety Standard. The estimated daily intake of OCPs from the halobios tested was also below the acceptable daily intake(ADI) recommended by FAO/WHO, indicating little health risk in halobios consumption for local residents.