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Xu N.,Liaocheng Vocational and Technical College | Wei M.,State Key Laboratory of Crop Biology | Wang C.,State Key Laboratory of Crop Biology | Shi W.,Shandong Agricultural University | And 2 more authors.
Allelopathy Journal | Year: 2013

The root exudates of Welsh onion (Allium fistulosum L.) were collected with the continuous root exudates trapping system and extracted with organic solvents of different polarities. The allelopathy of different extracted components on cucumber (Cucumis sativus L.) and Fusarium oxysporum f.sp. cucumerinum was studied and the composition was analyzed by using gas chromatography-mass spectrum (GCMS). All components extracted by different organic solvents promoted the growth of cucumber sprouts but inhibited the growth of F. oxysporum f.sp. cucumerinum mycelia. The components extracted by ethyl acetate had strongest allelopathic potential and were similar to those extracted by ether. Following further separation of major components, the allelopathy of components extracted by 80% ethyl acetate and 20% ethyl ether was strongest. The potential allelochemicals of Welsh onion root exudates were: diethyl phthalate, dibutyl phthalate, diisooctyl phthalate, 2-(methylthio)benzothiazole, benzothiazole, benzoic acid p-tolyl ester and cycluron. Dibutyl phthalate, benzoic acid, 4-methylphenyl ester and benzothiazole had significant allelopathic effects on the growth of cucumber sprouts and F. oxysporum f.sp. cucumerinum. Source

Zhou J.,Yunnan Normal University | Dong Y.,Liaocheng Vocational and Technical College | Gao Y.,Yunnan Normal University | Tang X.,Yunnan Normal University | And 5 more authors.
Biotechnology and Bioprocess Engineering | Year: 2012

The 774-bp pectate lyase gene plyAI4 from Bacillus sp. I4 was cloned and expressed in E. coli. The gene encodes a 257-residue polypeptide (PlyAI4, 28.3 kDa) with the highest identities of 97.3% with a putative pectate lyase from Bacillus subtilis BSn5 (ADV94306) and 60.3% with an identified pectate lyase of the polysaccharide lyase family (PL) 3 from Paenibacillus amylolyticus 27C64 (ADB78774). The purified recombinant PlyAI4 (rPlyAI4) exhibited apparently optimal activity at pH 10.5 ∼ 11.0 and 50°C. Compared with the majority of reported alkaline pectate lyases, rPlyAI4 exhibited more residual enzyme activity at 20°C (∼45%) or at 70°C (∼50%) and better thermostability at 70°C (∼60 min half-life at 70°C). In the presence of 20% (v/v) ethanol, pectate lyase activity was enhanced by 0.2 fold. After incubation in 40% (v/v) ethanol at 37°C and pH 8.5 for 1 h, the purified rPelAI4 retained more than 75% of the initial activity. Sequence analysis proposed a new signature block, A-D-G-[V/I]-H, for PL 3 pectate lyases. These properties may prove to be important with regards to PlyAI4 for basic research and industrial application. © The Korean Society for Biotechnology and Bioengineering and Springer 2012. Source

Huang X.,Liaocheng Vocational and Technical College
Advanced Materials Research | Year: 2012

The immersive feeling brought by virtual roaming system easily causes the user to got lost in it. In order not to lose direction in a three-dimensional virtual environment, usually a 2D map and the real-time current location of the user are provided so that the user can know his location in the 3D virtual environment action to take for the next step. However, since the parameter transformation is difficult to understand, the technology in virtual system of roaming is limited to use and promotion. This article analyzes the principle of 2D map and suggests the way to realize it based on Virtools. Special explanation is given to how to convert data in the three-dimensional coordinate to the 2D coordinate and the mapping relationship between the direction of the three-dimensional space and the direction of the two-dimensional maps. © (2012) Trans Tech Publications, Switzerland. Source

Xu Y.-X.,Northwest Normal University | Liu Z.-M.,Northwest Normal University | Liu Z.-M.,Liaocheng Vocational and Technical College | Lin M.-M.,Northwest Normal University | And 3 more authors.
Physics of Plasmas | Year: 2011

The collision between two ion-acoustic solitary waves with arbitrary colliding angle in an unmagnetized, ultracold quantum three-component e-p-i plasma has been investigated. By using the extended Poincaré-Lighthill- Kuo (PLK) perturbation method, we obtain the KdV equations and the analytical phase shifts after the collision of two solitary waves in this three-component plasma. The effects of the quantum parameter H, the ratio of Fermi positron temperature to Fermi electron temperature θ, the ratio of Fermi positron number density to Fermi electron number density μ, and the ratio of Fermi ion temperature to Fermi electron temperature ρ on the phase shifts are studied. It is found that these parameters can significantly influence the phase shifts of the solitons. © 2011 American Institute of Physics. Source

Ding X.,China University of Petroleum - East China | Yu X.C.,Liaocheng Vocational and Technical College | Sun H.X.,China University of Petroleum - East China
Advanced Materials Research | Year: 2013

Mesoporous molecular sieve MCM-41 was modified by using 3-mercaptopropyltriethoxysilane as a coupling agent and MCM-41 functionalized with sulfonic acid groups was prepared. The prepared product was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption technique and temperature programmed desorption. The results showed that during the process of modification the frameworks of the molecular sieve were not destroyed, the channel has ordered property. SH group was successfully grafted to the surface of channels of the molecular sieve. The acid amount on the mesoporous material functionalized with sulfonic acid groups reached 0.755mmol/g, showing a potential application foreground as a catalyst. © (2013) Trans Tech Publications,Switzerland. Source

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