365 research outputs found
ALUMINUMDODECATUNGSTOPHOSPHATE (Al0.9H0.3PW12O40) NANOTUBE AS A SOLID ACID CATALYST ONE-POT PRODUCTION OF BIODIESEL FROM WASTE COOKING OIL
Solid nanocatalyst aluminum dodecatungstophosphate (Al0.9H0.3PW12O40, abbreviated as AlPW) with nanotube structure was synthesized through a natural cellulose fiber template. The AlPW nanotubes, which are highly water-tolerant and acid-tolerant, can be described as green double acids, as they combine both BrĂžnsted and Lewis acid sites. They have been applied as an efficient nanoheterogeneous catalyst for the preparation of biodiesel from waste cooking oil containing 26.89 wt% high free fatty acids (FFAs) and 1% moisture via esterification of FFAs and transesterification of triglycerides in one pot under mild conditions
An Innovative Practice System of Information Management and Information System Specialty Based on Actual Projects
The practical teaching is the key link of training the studentsâ practical and creative ability in major of information management and information system. On the basis of analyzing the training goal and social demand of the major, an innovative practice system based on actual projects is constructed to solve the main problems exist in the practical teaching, by combining with the successful experience of the practical teaching innovation in Wuhan University of Science and Technology. The system provides a good practical teaching environment and an innovation practical platform for the cultivation of high quality innovation talents. To study in actual projects will accumulate the studentsâ project experience, cultivate their innovation consciousness and promote their competition ability
Heterologous expression, biochemical characterization, and overproduction of alkaline α-amylase from Bacillus alcalophilus in Bacillus subtilis
<p>Abstract</p> <p>Background</p> <p>Alkaline α-amylases have potential applications for hydrolyzing starch under high pH conditions in the starch and textile industries and as ingredients in detergents for automatic dishwashers and laundries. While the alkaline α-amylase gains increased industrial interest, the yield of alkaline α-amylases from wild-type microbes is low, and the combination of genetic engineering and process optimization is necessary to achieve the overproduction of alkaline α-amylase.</p> <p>Results</p> <p>The alkaline α-amylase gene from <it>Bacillus alcalophilus </it>JN21 (CCTCC NO. M 2011229) was cloned and expressed in <it>Bacillus subtilis </it>strain WB600 with vector pMA5. The recombinant alkaline α-amylase was stable at pH from 7.0 to 11.0 and temperature below 40°C. The optimum pH and temperature of alkaline α-amylase was 9.0 and 50°C, respectively. Using soluble starch as the substrate, the <it>K</it><sub>m </sub>and <it>V</it><sub>max </sub>of alkaline α-amylase were 9.64 g/L and 0.80 g/(L·min), respectively. The effects of medium compositions (starch, peptone, and soybean meal) and temperature on the recombinant production of alkaline α-amylase in <it>B. subtilis </it>were investigated. Under the optimal conditions (starch concentration 0.6% (w/v), peptone concentration 1.45% (w/v), soybean meal concentration 1.3% (w/v), and temperature 37°C), the highest yield of alkaline α-amylase reached 415 U/mL. The yield of alkaline α-amylase in a 3-L fermentor reached 441 U/mL, which was 79 times that of native alkaline α-amylase from <it>B. alcalophilus </it>JN21.</p> <p>Conclusions</p> <p>This is the first report concerning the heterologous expression of alkaline α-amylase in <it>B. subtilis</it>, and the obtained results make it feasible to achieve the industrial production of alkaline α-amylase with the recombinant <it>B. subtilis</it>.</p
A Study on Project-Driven Practice and Innovation Abilities of IT Studentsâ Club
IT studentsâ clubs play an irreplaceable role in training studentsâ innovation and practical abilities. Through questionnaires and interviews, the paper analyzes studentsâ participation in IT clubs, the training of studentsâ innovation and practical abilities and the problems existing in the organization management of clubs. By referring to the successful experience of Wuhan University of Science and Technology in the practice teaching reform, a âproject-drivenâ system for training practice and innovation abilities, which focused on training studentsâ innovation spirit and practical abilities, was established and achieved remarkable success
Color and Metallicity Distributions of M81 Globular Clusters
In this paper we present catalogs of photometric and spectroscopic data for
M81 globular clusters (GCs). The catalogs include B- and V- photometric and
reddening data of 95 GCs, and spectroscopic metallicities of 40 GCs in M81.
Using these data, we make some statistical correlations. The results show that
the distributions of intrinsic B and V colors and metallicities are bimodal,
with metallicity peaks at [Fe/H]=-1.45 and -0.53, respectively as has been
demonstrated for our Milky Way and M31. The relation between spectroscopic
metallicity and intrinsic B and V color also exists as it does for the Milky
Way and M31.Comment: Accepted for Publication in PASP, 9 pages, 6 figure
037-B327 in M31: Luminous Globular Cluster or Core of a Former Dwarf Spheroidal Companion to M31?
037-B327 is of interest because it is both the most luminous and the most
highly reddened cluster known in M31. Deep observations with the Advanced
Camera for Surveys on the Hubble Space Telescope provide photometric data in
the F606W band, and also show that this cluster is crossed by a dust lane. We
determined the structural parameters of 037-B327 by fitting the observed
surface brightness distribution to a King model with r_c=0.72" (=2.69 pc), and
r_t=5.87" (=21.93 pc), and a concentration index c=log(r_t/r_c)=0.91. The
surface brightness profile appears to be essentially flat within 0.25" of the
center and shows no signs of core collapse. Although the dust lane affects the
photometry, the King model fits the surface brightness profile well except for
the regions badly affected by the dust lane. We also calculate the half-light
radius r_h=1.11" (=4.15 pc). Combined with previous photometry, we find that
this object falls in the same region of the M_V versus log R_h diagram as do
Omega Centauri, M54 and NGC 2419 in the Milky Way and the massive cluster G1 in
M31. All four of these objects have been claimed to be the stripped cores of
former dwarf galaxies. This suggests that 037-B327 may also be the stripped
core of a former dwarf companion to M31.Comment: Accepted for Publication in ApJ Letter, 4 pages, 4 figure
Copper Affects Composition and Functioning of Microbial Communities in Marine Biofilms at Environmentally Relevant Concentrations
Copper (Cu) pollution in coastal areas is a worldwide threat for aquatic communities. This study aims to demonstrate the usefulness of the DNA metabarcoding analysis in order to describe the ecotoxicological effect of Cu at environmental concentrations on marine periphyton. Additionally, the study investigates if Cu-induced changes in community structure co-occurs with changes in community functioning (i.e., photosynthesis and community tolerance to Cu). Periphyton was exposed for 18 days to five Cu concentrations, between 0.01 and 10 ÎŒM, in a semi-static test. Diversity and community structure of prokaryotic and eukaryotic organisms were assessed by 16S and 18S amplicon sequencing, respectively. Community function was studied as impacts on algal biomass and photosynthetic activity. Additionally, we studied Pollution-Induced Community Tolerance (PICT) using photosynthesis as the endpoint. Sequencing results detected an average of 9,504 and 1,242 OTUs for 16S and 18S, respectively, reflecting the high biodiversity of marine periphytic biofilms. Eukaryotes represent the most Cu-sensitive kingdom, where effects were seen already at concentrations as low as 0.01 ÎŒM. The structure of the prokaryotic part of the community was impacted at slightly higher concentrations (0.06 ÎŒM), which is still in the range of the Cu concentrations observed in the area (0.08 ÎŒM). The current environmental quality standard for Cu of 0.07 ÎŒM therefore does not seem to be sufficiently protective for periphyton. Cu exposure resulted in a more Cu-tolerant community, which was accompanied by a reduced total algal biomass, increased relative abundance of diatoms and a reduction of photosynthetic activity. Cu exposure changed the network of associations between taxa in the communities. A total of 23 taxa, including taxa within Proteobacteria, Bacteroidetes, Stramenopiles, and Hacrobia, were identified as being particularly sensitive to Cu. DNA metabarcoding is presented as a sensitive tool for community-level ecotoxicological studies that allows to observe impacts simultaneously on a multitude of pro- and eukaryotic taxa, and therefore to identify particularly sensitive, non-cultivable taxa
Flavor Wheel Development and Sensory Quantitative Descriptive Analysis of Chinese Brewed Soy Sauce
Based on sensory descriptors developed by a sensory evaluation panel for 48 commercial Chinese brewed soy sauce samples, a flavor wheel of Chinese brewed soy sauce with 55 descriptors in the dimensions of aroma and flavor was developed for the first time. Meanwhile, a lexicon of sensory descriptors for brewed soy sauce containing reference samples with different intensities was established, and 20 brewed soy sauce samples of different grades and from different geographical origins were subjected to sensory evaluation by quantitative descriptive analysis (QDA) using this lexicon. The results showed that the characteristic flavor attributes of soy sauce were soy paste-like, salty, umami, Chinese herbal, and cooked soybean-like aromas. Through analysis of variance (ANOVA), principal component analysis (PCA) and discriminant analysis (DA), it was found that there were significant differences in sensory properties among soy sauce of different grades and from different regions. This study can provide a methodological reference for sensory quality analysis of Chinese brewed soy sauce
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