Modifying the acidity of H-MOR and its catalytic carbonylation of dimethyl ether

Among the reactions catalyzed by zeolites there are some that exhibit high selectivity due to the spatial confinement effect of the zeolite framework.Tailoring the acidity,particularly the distribution and location of the Bronsted acid sites in the zeolite is effective for making it a better catalyst for these reactions.We prepared a series of H-mordenite（H-MOR） samples by varying the composition of the sol-gel,using different structure directing agents and post-treatment.NH3-TPD and IR characterization of adsorbed pyridine were employed to determine the amount of Bronsted acid sites in the 8-membered ring and 12-membered ring channels.It was shown that controlled synthesis was a promising approach to improve the concentration of Bronsted acid sites in MOR,even with a low Al content.Using an appropriate composition of Si and Al in the sol-gel favored a higher proportion of Bronsted acid sites in the 8-membered ring channels.HMI as a structure-direct agent gave an obvious enrichment of Bronsted acid sites in the 8-membered ring.Carbonylation of dimethyl ether was used as a probe reaction to examine the modification of the acid properties,especially the Bronsted acid sites in the 8-membered ring channels.There was a linear relationship between methyl acetate formation and the number of Bronsted acid sites in the 8-membered ring channels,demonstrating the successful modification of acid properties.Our results provide information for the rational design and modification of zeolites with spatial constraints.

Global Attractor and Dimension Estimation for a 2D Generalized Anisotropy Kuramoto-Sivashinsky Equation

In this paper, firstly, some priori estimates are obtained for the existence and uniqueness of solutions of a two dimensional generalized anisotropy Kuramoto-Sivashinsky Equation. Then we prove the existence of the global attractor. Finally, we get the upper bound estimation of the Haus-dorff and fractal dimension of attractor.

Empirical Analysis on Relationship between Apple Futures and Spot Prices in China

Taking a total of 903 apple futures data from Zhengzhou Futures Exchange as research samples, and through unit root test, cointegration test, error correction, Granger causality test and variance decomposition with the aid of Eviews 8.0, this paper made an empirical analysis on the relationship between Zhengzhou apple futures market and Chinese apple website(pingguo7.cn) spot market price. It concluded that the main continuity of apple futures has an absolute advantage over the reference value of the futures index, and apple market participants can achieve hedging through the futures and spot market.

The Global Attractors of the Solution for 2D Maxwell-Navier-Stokes with Extra Force Equations

In this paper, we studied the solution existence and uniqueness and the attractors of the 2D Maxwell-Navier-Stokes with extra force equations.

Characteristics of gut microbiota determine effects of specific probiotics strains in patients with functional constipation

To the Editor:Probiotics are a promising treatment modality for functional constipation(FC);however,the factors affecting individual responses to probiotics remain unclear.Growing evidence has identified that there is a strong relationship among the gut microbiota and constipation and related gut-brain axis.[1]The gut microbiota may modulate the gut functions via gut metabolites or trigger the release of gut hormones,such as peptide YY,gastric inhibitory polypeptide,and 5-hydroxytryptamine.[2]In turn,gut hormones affect gut secretion,motility,and sensation through their receptors located on epithelial,enteric,and smooth muscle cells.[2]Based on these findings,exogenous probiotics have been used in patients with constipation;however,few have produced consistent results.[3]In this study,we investigated the efficacy and safety of several specific probiotics strains for constipation,and also examined the potential reasons for the individualized effects of probiotics,which may facilitate interventional decisionmaking for FC patients.

Bautype: Capsule and Lipopolysaccharide Serotype Prediction for Acinetobacter baumannii Genome

Acinetobacter baumannii has three clusters of genes for polysaccharide synthesis.Capsular polysaccharides and lipopolysaccharides are major virulence determinants in many Gram-negative bacteria,and play key roles in the overall fitness and virulence in A.baumannii,meanwhile poly-beta-1-6-N-acetylglucosamine was critical for biofilm formation.A variety of studies have been conducted which focused on the surveillance of antimicrobial resistance genes and clones in A.baumannii.However,a tool to perform serotype prediction in A.baumannii is still lacking.Here we present Bautype,a tool for whole genome sequencingbased K and O locus typing in A.baumannii.Using Bautype,users can upload and analyze the genome assembled in a web browser,with the results being displayed in a tabular or graphical format.We demonstrated the high accuracy of predicting K and O locus diversity using Bautype when analyzing more than 3000 A.baumannii genomes.Using our software,we were able to analyze K and O locus diversity among 593 genomes belonging to ST208(3 K and 8 O).These diverse loci can serve as epidemiological markers for Multi-drug Resistance(MDR)strain subtyping.We also identified 45 novel O locus types.Our findings highlight the importance in monitoring the capsule type and LOS of A.baumannii strains for which Bautype is a tailored clinical software.Bautype is available at http://BauType.net.