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Xi'an, China

Shaanxi Normal University is a key institution of higher education in People's Republic of China authorized to grant degrees in almost all kinds of subject. It was included in the 211 Project in 2006 and started its high-speed development.. Wikipedia.

Xu L.-W.,Hangzhou Normal University | Xu L.-W.,Shaanxi Normal University
ChemCatChem | Year: 2013

This minireview focuses on the recent advances in the synthetic application of amino acid-derived bifunctional phosphine catalysts bearing a hydrogen-bond donor. In the examples illustrated, the amino acid-based phosphines have already been proven to be versatile, catalyzing a wide range of asymmetric reactions, including (aza)-MBH reactions, [3+2] cyclizations, [4+2] cycloadditions, allylic alkylation, and Michael addition. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Yang P.,Shaanxi Normal University | Yang W.,Beijing University of Chemical Technology
Chemical Reviews | Year: 2013

Researchers discuss chemoselective phototransformation of C-H bonds on organic polymeric materials and related high-tech applications. New demands on polymer surfaces have led chemists to develop chemical systems that can directly convert C-H bonds on these soft organic material surfaces into functional groups or polymer chains in facile, efficient, specific, and selective ways. Several methods have been established for C-H transformations in molecules based on the use of different catalysts such as transition metal complexes, enzymes, and pure organic compound-catalyzed coupling methods. Examples based on photochemistry have emerged to achieve chemoselective activation of C-H bonds, which have become the emphasis of extensive discussion and summary. Top-down techniques such as photochemistry, which facilitate the preparation of gradient surfaces, have also found a wide range of applications in high-tech fields. Source

Liu Z.-H.,Shaanxi Normal University
Carbon | Year: 2010

A hybrid graphene/Ni2+-Fe3+ layered double hydroxide material has been fabricated by the hydrothermal treatment of a mixed suspension of the exfoliated graphite oxide, Ni(NO3)2 6H 2O, Fe(NO3)3·9H2O, urea and trisodium citrate. The Ni2+-Fe3+ layered double hydroxide platelets are first homogeneously grown on the surface of GO nanosheets which are then reduced to graphene under a mild hydrothermal treatment. In the hybrid graphene/Ni2+-Fe3+ layered double hydroxide material, the restacking of graphene nanosheets is effectively prevented by the formation of Ni2+-Fe3+ layered double hydroxide platelets, and the graphene nanosheets exist in a complete exfoliation state. © 2010 Elsevier Ltd. All rights reserved. Source

Li Y.,Shaanxi Normal University
Information Sciences | Year: 2011

In this paper, we study finite automata with membership values in a lattice, which are called lattice-valued finite automata. The extended subset construction of lattice-valued finite automata is introduced, then the equivalences between lattice-valued finite automata, lattice-valued deterministic finite automata and lattice-valued finite automata with -moves are proved. A simple characterization of lattice-valued languages recognized by lattice-valued finite automata is given, then it is proved that the Kleene theorem holds in the frame of lattice-setting. A minimization algorithm of lattice-valued deterministic finite automata is presented. In particular, the role of the distributive law for the truth valued domain of finite automata is analyzed: the distributive law is not necessary to many constructions of lattice-valued finite automata, but it indeed provides some convenience in simply processing lattice-valued finite automata. © 2010 Elsevier Inc. All rights reserved. Source

Zhu C.,Shaanxi Normal University | Liu X.,Shaanxi Normal University
Carbohydrate Polymers | Year: 2013

In this study, response surface methodology was employed to optimize the extraction process of crude polysaccharides from Pomegranate peel with water. Three independent and main variables, including extraction time (h), extraction temperature (°C) and ratio of water to raw material (ml/g), which were of significance for the yields of polysaccharides were studied and the Box-Behnken design was based on the results of a single-factors test. The experimental data were fitted to a second-order polynomial equation using multiple regression analysis and also examined using the appropriate statistical methods. The best extraction conditions are as follows: extraction time 1.9 h, extraction temperature 98 °C, ratio of water to raw material 37 ml/g. Under the optimization conditions, the experimental yield was 10.358%, which was well matched with the predictive yield of 10.423%. © 2012 Elsevier Ltd. Source

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