Characteristic of filamentous fungal diversity and dynamics associated with wheat Qu and the traditional fermentation of Chinese rice wine

Chinese rice wine, a traditional alcoholic beverage, is fermented from steamed rice with a starter culture of wheat Qu which is either inoculated spontaneously with various microorganisms in natural environment or inoculated artificially with certain microorganisms. The diversity of filamentous fungi in wheat Qu and the fermentation mashes of Chinese rice wine was studied by high‐throughput sequencing. The results indicated that filamentous fungi varied in wheat Qu and fermentation periods. Moreover, Aspergillus was the dominant filamentous fungi at genus levels. On that basis, quantitative real‐time PCR was used to quantify some dominant Aspergillus species. It was found that Aspergillus species in wheat Qu were more abundant than that in various fermentation mashes and continually decreased until the end of rice wine fermentation. Furthermore, it was found that different organic acids were produced by microorganisms at different fermentation stages might due to the changes of oxygen and nutrient content.     

Isolation,purification, and antioxidant activities of polysaccharides from Ziziphus Jujuba cv. Muzao

In the present study, crude polysaccharides from Ziziphus Jujuba cv. Muzao were isolated and purified using DEAE cellulose-52 and Sephadex G-100 size-exclusion chromatography; four fractions were collected, namely GZMP-1, GZMP-2, GZMP-3, and GZMP-4. The molecular weights of these four fractions were measured to be 111.2, 95.1, 84.2, and 571.4 kDa, respectively, using high-performance gel permeation chromatography. Gas chromatography analysis of the monosaccharide composition confirmed that GZMP-1 was composed of rhamnose, arabinose, glucose, and galactose. Rhamnose, arabinose, and galactose were the main components present in GZMP-2 and GZMP-3, whereas GZMP-4 was composed of only rhamnose and arabinose. Scanning electron microscopy showed relatively smooth surfaces for GZMP-1 and GZMP-4, whereas GZMP-2 and GZMP-3 had more folds on their surfaces. Fourier transform infrared spectroscopy analyses indicated that GZMP-1 and ZMP mainly had α-type glycosidic linkages. The in vitro antioxidant activities of the polysaccharides revealed that jujube polysaccharides exhibit remarkable antioxidant activity, and can scavenge DPPH radical and OH radical in a concentration-dependent manner. The results of this work suggest that polysaccharides from Z. Jujuba cv. Muzao have potential to be used as functional food and in the development of natural antioxidant drug carriers.     

Leader-following consensus of fractional-order multi-agent systems via adaptive control

This article focuses on the consensus problem of leader-following fractional-order multi-agent systems (MASs) with general linear and Lipschitz nonlinear dynamics. First, the distributed adaptive protocols for linear and nonlinear fractional-order MASs are constructed, respectively. We allow the control coupling gains to be time varying for each agent. Moreover, the adaptive modification schemes for the control gain are designed, which renders smaller control gains and thus requires smaller amplitude on the control input without sacrificing consensus convergence. Second, based on fractional-order Lyapunov stability theorem and Barbalat's lemma, two novel sufficient conditions in terms of linear matrix inequalities are provided to ensure that the leader-following consensus can be obtained in the case for any undirected connected communication graph. Furthermore, we show that the proposed algorithm also works for consensus of agents with intrinsic Lipschitz nonlinear dynamics. As a result, the proposed framework requires no global information and thus can be implemented in a fully distributed manner. Finally, the numerical simulations are given to demonstrate the effectiveness of obtained the theoretical results.     

Analysis of phase transition,structural and dynamical properties of R290 using molecular dynamics simulation

Propane (R290), a hydrocarbon refrigerant, is an excellent choice of cooling fluids for use in refrigeration and air conditioning systems considering the environmental point of view and system performance. The phase transition phenomenon and structural and dynamic properties of R290 were analyzed through a molecular dynamics (MD) simulation. The densities, isobaric heat capacities and viscosities were computed and the variations of density, volume, potential energy and the nucleation process were examined to investigate the effects of condensation temperature on the phase transition rate. The mean square displacement and velocity autocorrelation function for different temperatures were simulated for dynamical analysis. Radial distribution functions were investigated to get insight into the structural analysis at the atomic level. Shear viscosity and isobaric heat capacity obtained by the present simulation showed a good agreement with the REFPROP data. The structural analysis revealed that the phase transition of R290 did not affect its intramolecular structure.

     

Influence of hexapod robot foot shape on sinking considering multibody dynamics

Journal of Mechanical Science and Technology - Hexapod robots have attracted attention for their excellent terrain adaptabilities. When a robot walks on soft soil, dynamic subsidence and slippage...