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Expression and characterization of a novel GH128 laminarinase OUC-BsLam26 harboring both hydrolyzing and transferring activities

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Food science and Human Wellness 2024年

作者： yueyang Dong Yongyi Quan Hong Jiang Hamed I.Hamouda Zewei Lu Yimiao Chen Chengqiang li Xiangzhao Mao State Key Laboratory of Marine Food Processing and Safety Control， College of Food science and Engineering， Ocean University of china Qingdao Key Laboratory of Food Biotechnology Sanya Ocean Research institute， Ocean University of china Processes Design and Development Department， Egyptian Petroleum Research institute Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine science and technology Key Laboratory of Biological Processing of Aquatic Products，china.National light Industry

Laminarin oligosaccharides (LOSs) with a specific degree of polymerization prepared through the laminarin degradation via laminarinase present more significant nutritional functions and application values. Human intestinal bacteria are promising potential producers of novel carbohydrate-active enzymes with unique properties. Here， a novel glycoside hydrolase family 128 (GH128) laminarinase OUC-BsLam26 from the intestinal bacterium Bacteroides sp. CBA7301 was heterologously expressed and characterized. The recombinant OUC-BsLam26 with a molecular mass of 49.86 kDa exhibits highest activity (6.60 U/mg) at 45 ℃ and pH 6.0， which shows noticeable temperature and pH stability. The purified OUC-BsLam26 could degrade laminarin via an endo-type mode with the generation of laminaripentaose， laminaritetraose， laminaritriose， and laminaribiose， among them， laminaritetraose is the principal product， which accounts for 45.25% of the total products， which is significantly different from the reported GH128 laminarinases. The minimum recognition substrate of OUC-BsLam26 is laminarihexaose. Furthermore， OUC-BsLam26 also could catalyze the transglycosylation process with the production of some novel glycosides. Altogether， the intestinal bacterium Bacteroides sp. CBA7301 contains laminarinase with unique product composition and OUC-BsLam26 is a hopeful bio-catalyst with the potential to produce laminaritetraose and some novel glycosides.

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Catalysts for decomposing ozone tail gas

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Journal of Environmental sciences 2003年第6期15卷 779-782页

作者： liU Chang-an, SUN De-zhi, WANG Hui, li Wei (Department of Environmental science and Engineering, Harbin institute of technology, Harbin 150001,china. Department of Environmental science and Engineering Harbin Institute of Technology Harbin 150001

The preparation of immobilizing-catalysts for decomposing ozone by using dipping method was studied. XRD, XPS and TEM were used to characterize the catalysts. The three kinds of catalysts were selected preferentially, and their catalytic activities were investigated. The results showed that the catalyst with activated carbon dipping acetate(active components are Mn:Cu=3:2, active component proportion in catalyst is 15%, calcination temperature is 200℃) has the best catalytic activity for ozone decomposing. One gram of catalyst can decompose 17.6 g ozone at initial ozone concentration of 2.5 g/m 3 and the residence time in reactor of 0.1 s. The experimental results also indicated that humidity of reaction system had negative effect on catalytic activity.

关键词： ozone tail gas catalytic decomposition immobilizing-catalyst MnO 2 CuO

Tuning surface active oxygen of lanthanum oxide via partial dissolution and regrowth of crystallites

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Journal of Natural Gas Chemistry 2011年第5期20卷 483-486页

作者： Zhiming Gao, Huili li Key Laboratory of Cluster science, Ministry of Education of china.Department of Chemistry, School of science, Beijing institute of technology, Beijing 100081, china Key Laboratory of Cluster science Ministry of Education of China Department of Chemistry School of Science Beijing Institute of Technology Beijing 100081 China

A commercial lanthanum oxide was modified into X%-La2O3 samples via partial dissolution and regrowth of crystallites, wherein the X value denotes the weight percent of the initial metal oxide powder dissolved by nitric acid. BET measurements and TEM observations indicate that the 20%-La2O3 sample has an increased specific surface area, relatively thin and small crystallites in size. TPD/TPR profiles also show that the 20%-La2O3 sample has more surface active oxygen than the 0%-La2O3 sample. Among the four X%-La2O3 samples, the highest activity for methane oxidation was obtained over the 20%-La2O3 sample. Therefore, the present work proves that the method of partial dissolution and regrowth of crystallites are effective to modify surface property of lanthanum oxide.

关键词： solid state reaction surface oxygen crystallite regrowth TPR metal oxide

ON THE EXISTENCE OF SOLUTIONS TO A TYPE OF NONliNEAR DIFFERENTIAL-ITERATIVE EQUATIONS

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Chinese Annals of math.matics,Series B 2000年第2期21卷 217-224页

作者： GE WEIGAO(Department of Applied math.matics, Beijing institute of technology, Beijing 100081, china.) li CUIZHE(Department of Applied math.matics, Beijing institute of technology, Beijing 100081, china.) YU YUANHONG(Inditute of Applied math.matics, Acad Department of Applied math.matics Beijing Institute of Technology Beijing 100081 China institute of Applied math.matics Academia Sinica Beijing 100080 China

Under the assumption that h(z) is strictly monotone the existence of solutions to a type of nonlinear differential-iterative equations in the form of x’(t) = g(x(t)) -h(x(x(t))) is discussed according to the behavior... 详细信息

关键词： Differential-iterative equation Quasi-isoclinic curve Fixed point

The Spectral Method for the Flow between Two Concentric Rotating Spheres, Part I:The Full Discrete Nonlinear Legendre-Galerkin Method

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Communications in Nonlinear science and Numerical Simulation 1998年第4期3卷 211-214页

作者： Weibing FENG and Kaitai li (institute of Appl. math. & Mech., Shanghai Uni., Shanghai 200072, china.(science College, Xi’an Jiaotong University, Xi’an 710049, china.E--mail: glliu@*** institute of Appl. math. and Mech. Shanghai Univ. Shanghai 200072 China science College Xi'an Jiaotong University Xi'an 710049 China

The nonlinear Galerkin methods are numerical schemes for evolutionary partial differential equations based on the theory of inertial manifolds and approximate inertial manifolds. In this paper, we consider the flow between two concentric rotating spheres, and combine the Legendre-Galerkin spectral methods in Part I together with the nonlinear Galerkin method, then construct the full discrete nonlinear Legendle-Galerkin spectral scheme, and derive the stability conditions and its error estimate.

关键词： Navier-Stokes equations nonlinear Galerkin method stream function

Enhanced activity of yqhD oxidoreductase in synthesis of 1,3-propanediol by error-prone PCR

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Progress in Natural science:Materials International 2008年第12期18卷 1519-1524页

作者： Hongmei li~a Jia Chen~a Yinghua li~b a institute of Food science and Biological technology,University of Shanghai for science and technology,Shanghai 200093,china.b institute of Pharmaceutical Engineering,Zhejiang University,Hangzhou 310027,china institute of Food science and Biological technology University of Shanghai for Science and Technology Shanghai 200093 China institute of Pharmaceutical Engineering Zhejiang University Hangzhou 310027 China

yqhD oxidoreductase was determined to be an NADP-dependent dehydrogenase,and was more active toward 3-HPA when compared to 1,3-propanediol *** further improve enzyme activity towards 3-hydroxypropionaldehyde (3-HPA),error-prone PCR was implemented to mutant yqhD *** mutants,D99QN147H and Q202A with increased catalytic and affinity efficiency,were obtained after one round of error-prone polymerase chain *** the catalytic efficiency of the mutant D99QN147H was up to 4-fold greater than the wild enzyme (0.0375 min-1mM-1vs.0.0078 min-1mM-1).The recombined strain containing pEY28yqhD D99QN147H yielded 28 g L-1of 1,3-propanediol in the fed-batch LB cultures (1 L volume) with an initial 3-HPA concentration of 40 g L-1,which was higher than the 21 and 17 g L-1of 1,3-propanediol from the mutant Q202A and the wild-type,*** for propionaldehyde,the optimal mutant D99QN147H also exhibited higher activity on a range of substituted aldehydes than the wild- type.

关键词： yqhD oxidoreductase Error-prone PCR Catalytic efficiency 1,3-Propanediol

REACTION MODEL IN Al-Ti-C SYSTEM

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Acta Metallurgica Sinica(English Letters) 1995年第2期8卷 137-140页

作者： WANG Zidong HU Hanqi(University of science and technology Beijing.Beijing,china.li Qingchun(Harbin institute of technology,Harbin.china Univ of science and technology Beijing China

In this Paper,interaction coefficients among Al,Ti and C in Al-Ti-C ternary system and actual free energy of Al_3Ti,TiC and Al_4C_3,were calcutated via ternary alloy thermodynamic *** rsults show that,at low temperatures,Al_3Ti forms through the reaction of aluminium with titanium,and at high temperatures,the TiC forms hy the reaction of carbon with Al_*** reaction mechanism was verified by the experimental results.

关键词： thermodynamics reaction mechanism Al-Ti-C.system

Modeling of the Shape Forming of Composite Roll

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Journal of Materials science & technology 2000年第3期16卷 337-340页

作者： Chengsong CUI, Zhenyu li, Fuyang CAO and Qingchun li (School of Materials science and Engineering, Harbin institute of technology, 150001, china. School of Materials science and Engineering Harbin Institute of Technology China

A shape modeling of spray formed composite roll, which is utilized to predict the shape and dimension of roll during spray forming process, is developed in this paper. The influences of the principal spray forming parameters, such as the spatial distribution of melt mass flux, spray distance, rotating and translating speeds of substrate bar etc. , on the geometry and dimension of spray formed product were investigated.

关键词： Modeling of the Shape Forming of Composite Roll

Grey Model of the Investment Portfolio Optimization

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Systems science and Systems Engineering 2002年第2期11卷 143-149页

作者： li QunDept. of Applied math. , Dalian Univeristy of technology Dalian 116024, china Dept. of Applied math. Dalian Univeristy of Technology Dalian 116024 China

The theory of investment portfolio is a very important theory in the modern economical system. Based on the feature of the theory, the paper sets up new various kinds of models of investment portfolio, namely grey opt... 详细信息

关键词： investment portfolio expected return risk grey optimization model