Modified Kedem-Katchalsky equations for osmosis through nano-pore

This work presents a modified Kedem-Katchalsky equations for osmosis through nano-pore. osmotic reflection coefficient of a solute was found to be chiefly affected by the entrance of the pore while filtration reflection coefficient can be affected by both the entrance and the internal structure of the pore. Using an analytical method, we get the quantitative relationship between osmotic reflection coefficient and the molecule size. The model is verified by comparing the theoretical results with the reported experimental data of aquaporin osmosis. Our work is expected to pave the way for a better understanding of osmosis in bio-system and to give us new ideas in designing new membranes with better performance.Comment: 19 pages, 4 figure

Effect of Microbial Community in Artificial Pit Mud on the Formation of Flavor Metabolites during the Fermentation of Nongxiangxing Baijiu

In this study, a small-scale simulated fermentation system of fermented grains (Jiupei in Chinese) without pit mud (PM) was used as a control, and the differences in the microbial community and metabolite components between the PM and control groups were compared. The results indicated that PM significantly enhanced the contents of major flavor compounds in Jiupei including butyric acid, caproic acid, ethyl acetate, ethyl butyrate, and ethyl caproate, and reduced the contents of lactic acid and ethyl lactate. For both groups, the relative abundance of Lactobacillus, one of the dominant bacteria in the upper and bottom layers of Jiupei, significantly increased at the initial stage, and showed a slight difference between them at the end of fermentation. The decay period of Lactobacillus in the PM group was about 15 days earlier than that in the control group. At the same time, the relative abundance of Rhodococcus in the control group, and the relative abundance of Kroppenstedtia, Clostridium_sensu_stricto_12, and Acetobacter in the PM group increased. The abundance of most of the enzymes in the Embden-Meyerhof-Parnas (EMP) pathway, as well as that of caproic acid synthase (EC 1.3.1.38, EC 2.3.1.16, EC 6.2.1.1) and butyric acid synthase (EC 2.3.1.9, EC 2.8.3.8) increased during fermentation, and the abundance of these enzymes was significantly higher in the bottom layer of Jiupei than in the upper layer. The abundance of lactate dehydrogenase (EC 1.1.1.27), which uses lactic acid as a substrate, increased in the PM group. These findings reveal the contribution of PM to the microbial communities and metabolite components of Jiupei

Effect of Spatial Heterogeneity on the Microbial Community of Daqu, a Fermentation Starter for Chinese Baijiu

The effect of spatial heterogeneity on the microbial community and physicochemical properties during the primary fermentation of Daqu were investigated by high-throughput sequencing technology and conventional detection methods. Nongxiangxing baijiu Daqu inoculated with the unique ripe starter obtained by gradually culturing and expanding Daqu treated by cosmic rays was used. The results showed that although the intensity of change in driving factors varied among layer, their trends were the same. The liquefying, saccharifying and esterifying power of Daqu were higher in the bottom layer than in the upper and middle layers at the same fermentation time and the fluctuation was small. The microbial community of Daqu was composed of 12 dominant bacterial genera, including Lactobacillus, Weissella, Bacillus, Kosakonia, Staphylococcu and Thermoactinomyces, and seven dominant fungal genera, such as Pichia, Thermoascus, and Rhizomucor. Principal co-ordinates analysis and hierarchical clustering analysis showed significant differences in the bacterial and fungal community structure among fermentation stages and layers. Procrustes analysis and Mantel test showed that moisture had a significant effect on the bacterial community in Daqu, and acidity had a significant effect on the bacterial community in the middle and bottom layers of Daqu. Moreover, moisture had a significant effect on the fungal community in the upper and middle layers of Daqu. Redundancy analysis showed that moisture and acidity were positively correlated with Lactobacillus and Pichia, while driving factors had different influences on the microbial communities in different layers of Daqu. Therefore, the interaction and co-occurrence patterns of microbial genera in Daqu could change due to the differences in driving factors among different layers of Daqu. These results suggested that regulating driving factors during the Daqu making process is an effective way to improve the microbial community structure and quality of Daqu

BJ_MARGA_Surfacedata.xlsx

Observations at BJ station</p

Differential Hydrological Properties of Forest Litter Layers in Artificial Afforestation of Eroded Areas of Latosol in China

Litter is one of the key components of the forest ecosystem and plays a role as the second active layer influencing hydrological processes, which has affected the global water cycle. Soil- and water-conservation forests were constructed by artificial afforestation as a part of vegetation restoration in the eroded area of Latosol, and little is known about the differences in the hydrological properties of vegetation restoration in the eroded area of Latosol in the tropical region. We investigated the litter thickness, mass, and hydrological properties in three soil- and water-conservation forests (Eucalyptus robusta, Hevea brasiliensis, and Acacia mangium) through in situ surveys and laboratory experiments. The results showed that (1) the total litter thickness varied from 2.16 to 5.53 cm and was highest in the A. mangium forest. The total litter mass for A. mangium, 14.66 ± 1.09 t·ha−1, was significantly higher than that for E. robusta (5.45 ± 0.59 t·ha−1) and H. brasiliensis (3.01 ± 0.14 t·ha−1). The mass of the semi-decomposed litter (SDL) layer was markedly higher than that of the un-decomposed litter (UDL) layer. (2) The maximum water-retention capacity (Wmax) and effective water-retention capacity (Weff) of the SDL layer were larger than the UDL layer for three forest plantations. The Wmax and Weff for the A. mangium stand were significantly higher than those for the E. robusta and H. brasiliensis stand. (3) The water-absorption rate of the SDL and UDL layer were highest at the onset of the immersion experiment, declined exponentially with time, and especially declined rapidly in the first 2 h. A higher water-holding capacity of A. mangium may be more effective in enhancing rainfall interception, minimizing splash erosion, and decreasing surface runoff. These results indicate that planting A. mangium in E. robusta and H. brasiliensis forests and then turning them into mixed forests should improve soil and water conservation and maximize their ecological benefits

Numerical Simulation on the Influence of heating with Different Arrangement of Burners on the High Performance Hydrogen Bell-type

numerical simulation Abstract. The heating bell with burners is an important heating device for the high performance hydrogen bell-type annealers. The arrangement of the burners has an important impact on the heating effect. In this study, we simulated a series of model with different location of burners under the same quantity of burners and the same heating power. The result shows: (1) Under the same quantity of burners and the same heating power, when we increase the number of rows of burners, the maximum temperature inside the furnace could be reduced, and the temperature distribution will become more uniform; (2)When we fixed the number of the row of the burners, if we move the upper burners to higher position to make the arrangement of burners more uniform, the temperature distribution inside the furnace will be more uniform, this will be good for the heat transfer to the higher parts of the annealers, and this will accelerate the heating process, improve the efficiency of annealing, reduce fuel consumption, and extend the life of the inner bell