Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development

Nanning, China

Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development

Nanning, China
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Chen W.,Guangxi University | Liu D.,Guangxi University | Wu W.,Guangxi University | Wu W.,Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development | And 2 more authors.
Journal of Magnetism and Magnetic Materials | Year: 2017

A series of Dy3+ doped Co–Ni–Zn ferrites with the formula Co0.5Ni0.25Zn0.25DyxFe2−xO4 0≤x≤0.24) have been successfully synthesized using the solvothermal method. X-ray diffraction and scanning electron microscope examinations indicate that a highly-crystallized cubic Co0.5Ni0.25Zn0.25DyxFe2−xO4 with rod-like morphology is obtained when the precursor is calcined at 1000 °C in air for 3 h. Single phase Co0.5Ni0.25Zn0.25Fe2O4 is obtained at 650 °C, but all samples consist of the main spinel phase in combination of a small amount of a foreign Dy2O3 phase after doping Dy. When the precursor is calcined at 1000 °C, the lattice parameter of the ferrites initially increase after doping Dy, but then become smaller with increasing Dy content. The addition of Dy content results in a reduction of crystallite size, attributed that the binding energy of Dy3+–O2− is larger than that of Fe3+–O2−. Dy3+ substitution can decrease the remanence (Mr) and coercivity (Hc) of Co0.5Ni0.25Zn0.25DyxFe2−xO4 samples, which are very desirable characteristics for high density data storage devices. © 2016 Elsevier B.V.


Chen W.,Guangxi University | Wu W.,Guangxi University | Wu W.,Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development | Wu X.,Guangxi University | And 3 more authors.
Journal of Materials Science: Materials in Electronics | Year: 2017

Co0.5Ni0.3Zn0.2AlxFe2−xO4 (0.0 ≤ x ≤ 0.21) rods are synthesized by a solvothermal method using glycol as template and surfactant. X-ray diffraction, scanning electron microscope, and vibrating sample magnetometer are employed to evaluate structural, morphology, and magnetic properties of the as-prepared ferrites. The X-ray diffraction analysis indicates that single phase spinel ferrites are obtained when the precursor is calcined above 750 °C in air for 3 h. After being calcined at 950 °C, the lattice parameters of the ferrites initially decrease with increase in Al3+ content, but then increase (x = 0.21). The addition of Al3+ ion decreases the average crystallite size. This is because the electron orbital tends to be completed. The scanning electron microscope micrographs of the synthesized samples show the presence of large-area arrays of ferrite rods. The possible formation mechanism for the synthesis of ferrites rods has been preliminarily explained. Magnetic property tests indicates that when the Al3+ doping amount is increased from 0 to 0.21, the specific saturation magnetization (Ms) values initially increase from 74.37 to 80.01 emu/g and then decrease to 76.77 emu/g, while the coercivity (Hc) values increase from 245.61 to 345.96 Oe at first, then decrease to 317.04 Oe. The results can be explained by Neel’s two sublattice and Yafet-Kittle configuration models. © 2017 Springer Science+Business Media New York


Chen W.,Guangxi University | Wu W.,Guangxi University | Wu W.,Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development | Liu D.,Guangxi University | Wu J.,Guangxi University
Journal of Materials Science: Materials in Electronics | Year: 2016

Four kinds of Ni–Cu–Mg based ferrites materials having the general formula Ni0.5Cu0.25Mg0.25DyxFe2−xO4 (0.0 ≤ x ≤ 0.24) have been successfully synthesized using the solvothermal method. X-ray diffraction and scanning electron microscope examinations confirm that a rod-like Ni0.5Cu0.25Mg0.25DyxFe2−xO4 with cubic spinel structure is obtained when the precursor is calcined above 850 °C in air for 3 h. Single phase Ni0.5Cu0.25Mg0.25Fe2O4 is obtained at 850 °C, but all samples consist of the main spinel phase in combination of a small amount of foreign Dy2O3 and/or DyFeO3 phases after doping Dy3+. When the precursor is calcined at 1000 °C, the lattice parameters of the ferrites initially decrease after doping Dy3+(x = 0.08), but then become larger with additional Dy3+ doping. The addition of Dy3+ decreases the average crystallite size, and results in higher coercivity (Hc) and squareness (Mr/Ms) as compared to un-substituted Ni–Cu–Mg ferrites. In this study, Ni0.5Cu0.25Mg0.25Dy0.24Fe1.76O4, obtained at 1000 °C, exhibits the highest coercivity of 149.29 Oe and squareness (0.3055). © 2016 Springer Science+Business Media New York


Wu X.,Guangxi University | Chen W.,Guangxi University | Wu W.,Guangxi University | Li H.,Guangxi University | Lin C.,Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development
Journal of Electronic Materials | Year: 2016

Four types of Co-Ni based ferrites materials with the general formula LixCo0.5Ni0.5−xFe2O4 (0.0 ≤ x≤0.3) were successfully synthesized by thermal decomposition of oxalates in air. The effect of substitution of diamagnetic Li+ ions for partial Ni2+ ions in a spinel lattice on the crystalline structure and the magnetic properties of Co-Ni ferrites was studied. X-ray diffraction examination confirms that a high-crystallized LixCo0.5Ni0.5−xFe2O4 with cubic spinel structure is obtained when the precursor is calcined at 900°C in air for 3 h. The substitution of Li+ ions for partial Ni2+ ions does not change the spinel crystalline structure of MFe2O4, but crystallinity of LixCo0.5Ni0.5−xFe2O4 can be improved. The incorporation of Li+ ions in place of Ni2+ ions in Co-Ni ferrites decreases the average crystallite size and results in higher specific saturation magnetization as compared to un-substituted Co-Ni ferrites. In this study, Li0.1Co0.5Ni0.4Fe2O4, obtained at 900°C, exhibits the highest specific saturation magnetization of 88 emu/g ± 2 emu/g and magnetic moment (3.60 μB ± 0.05 μB). © 2016 The Minerals, Metals & Materials Society


Chen Z.,Guangxi University | Hu W.,Guangxi University | Wang M.,Guangxi University | Wang L.,Guangxi University | And 3 more authors.
Carbohydrate Research | Year: 2016

A glycosyl-rhodamine fluorescent probe with good water-solubility has been designed and synthesized through click reaction. Compared with control compound 1, the obtained target compound (RBGlc-3) could be independently applied for the detection of Hg2+ in water medium, and not disturbed by Ce3+, Eu3+, Ca2+, Cd2+, Fe2+, Ba2+, Co2+, Cu2+, Zn2+, Pb2+, Mg2+, Ni2+, K+, Ag+, Na+, NH4 +, CH3COO-, S2O4 2-, SO4 2-, SO3 2- and Cl-. 1:1 Stoichiometry is the most likely recognition mode of RBGlc-3 toward Hg2+ ion, and the OFF-ON fluorescent mechanism of RBGlc-3 is proposed. © 2016 Elsevier Ltd.


Du C.-R.,Guangxi University | Lu D.-W.,Guangxi University | Shi K.,Guilin University of Electronic Technology | Chen D.-D.,Guangxi University | And 2 more authors.
Faguang Xuebao/Chinese Journal of Luminescence | Year: 2015

Because of the excellent properties and wide applications of cinnamamide medicines in clinic, three m-hydroxycinnamic acid derivatives were designed and synthetised by the reaction of m-hydroxybenzoic acid with different amino acids, respectively. Their structures were characterized by mass spectrometry, infrared spectroscopy, and nuclear magnetic resonance. The interaction mechanism of derivatives and human serum albumin (HSA) were investigated by AutoDock molecular docking, fluorescence spectroscopy and UV-visible absorption spectroscopy. The results of molecular docking represent that derivatives exist in the hydrophobic pocket of subdomain II A (site I) of HSA. Hydrogen bonds and van der Waals' forces are main acting forces and hydrophobic force is just the secondary consideration. The spectra experiment results indicate that the derivatives can form complexes with HSA respectively and strongly quench the intrinsic fluorescence of HSA through static quenching at different temperatures. Meanwhile, the secondary structure of HSA is influenced. The change in enthalpy (ΔH) and entropy (ΔS) suggest that hydrogen bonds and van der Waals forces are main acting forces. The molecular docking data are consistent with experimental results. © 2015, Science Press. All right reserved.


Zhou Y.,Guangxi University | Chen W.,Guangxi University | Shen Y.,Guangxi University | Wu X.,Guangxi University | And 3 more authors.
Journal of Magnetism and Magnetic Materials | Year: 2015

LixCu0.6Mg0.4-xFe2O4 (0.0≤x≤0.3) is obtained by calcining precursor oxalates over 900 °C in air. The precursor and its calcined products are characterized by thermogravimetry and differential scanning calorimetry, X-ray powder diffraction, scanning electron microscopy, and vibrating sample magnetometer. A high-crystallized LixCu0.6Mg0.4-xFe2O4 with a cubic structure is obtained when the precursor is calcined at 900 °C in air for 3 h. The lattice constants of the ferrites decrease after Li+ doping. Magnetic properties of LixCu0.6Mg0.4-xFe2O4 depend on the composition and calcination temperature. Cu0.6Mg0.4Fe2O4 obtained at 900 °C has the highest specific saturation magnetization value, 42.44 emu/g; remanence value of Li0.2Cu0.6Mg0.2Fe2O4 obtained at 900 °C is close to zero. © 2015 Elsevier B.V. All rights reserved.


Huang X.,Guangxi University | Chen W.,Guangxi University | Wu W.,Guangxi University | Wu W.,Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development | And 4 more authors.
Journal of Materials Science: Materials in Electronics | Year: 2016

The effect of cobalt doping on the structure and magnetic properties of polycrystalline La0.6Ca0.4Mn1−xCoxO3 (0 ≤ x≤0.3) has been studied. X-ray powder diffraction and magnetization measurements have been performed. A high-crystallized La0.6Ca0.4Mn1−xCoxO3 with an orthorhombic structure is obtained when the precursor is calcined at 900 °C in air for 3 h. Different amounts of Co3+ ion doping do not lead to the formation of another phase except diffraction peaks shifts slightly. With increase in Co3+ doping from x = 0, 0.1, 0.2, to 0.3, lattice parameters (b value) increase at first, then decrease. Magnetic characterization indicates that specific magnetization of La0.6Ca0.4Mn1−xCoxO3 decreases with the increase of Co3+ additional amount; substitution of Mn by Co3+ ion can markedly increase the coercive field of La0.6Ca0.4Mn1−xCoxO3, attributed that Co3+ doping can decrease Mn3+/Mn4+ ratio in La0.6Ca0.4Mn1−xCoxO3. La0.6Ca0.4Mn0.7Co0.3O3 at 100 K had the highest coercive field value, 1889.7 Oe. The coercive field of La0.6Ca0.4Mn1−xCoxO3 is between 35.1 and 114.7 Oe, even at 200 K, indicating that La0.6Ca0.4MnO3 and doped Co3+ La0.6Ca0.4Mn1−xCoxO3 continue being ferromagnetic at 200 K. © 2016 Springer Science+Business Media New York


Tian J.,Northeast Agricultural University | Tian J.,CAS Institute of Microbiology | Chen H.,CAS Institute of Microbiology | Chen H.,Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development | And 7 more authors.
Applied Microbiology and Biotechnology | Year: 2016

Many novel microbial nature products were discovered from Actinobacteria by genome mining methods. However, only a few number of genome mining works were carried out in rare actinomycetes. An important reason precluding the genome mining efforts in rare actinomycetes is that most of them are recalcitrant to genetic manipulation. Herein, we chose the rare marine actinomycete Streptosporangium sp. CGMCC 4.7309 to explore its secondary metabolite diversity by genome mining. The genetic manipulation method has never been established for Streptosporangium strains. At first, we set up the genetic system of Streptosporangium sp. CGMCC 4.7309 unprecedentedly. The draft genome sequencing of Streptosporangium sp. CGMCC 4.7309 revealed that it contains more than 20 cryptic secondary metabolite biosynthetic clusters. A type II polyketide synthases-containing cluster (the hex cluster) was predicted to encode compounds with a pentangular polyphenol scaffold by in silico analysis. The products of the hex cluster were uncovered by comparing the metabolic profile of Streptosporangium sp. CGMCC 4.7309 with that of the hex30 inactivated mutant, in which a key ketoreductase gene was disrupted. Finally, three pentangular polyphenols were isolated and named as hexaricins A (1), B (2), and C (3). The inconsistency of the stereochemistry of C-15 in hexaricins A, B, and C indicates a branch point in their biosynthesis. Finally, the biosynthetic pathway of the hexaricins was proposed based on bioinformatics analysis. © 2016 Springer-Verlag Berlin Heidelberg


Huang X.,Guangxi University | Zhou Y.,Guangxi University | Wu W.,Guangxi University | Wu W.,Guangxi Colleges and Universities Key Laboratory of Applied Chemistry Technology and Resource Development | And 4 more authors.
Journal of Electronic Materials | Year: 2016

A series of Zn2+ doped Co–Cu ferrites with the formula Co0.5Cu0.5−xZnxFe2O4 (0.0 ≤ x ≤ 0.3) have been successfully synthesized using the solvothermal method. X-ray diffraction and scanning electron microscopy results indicate that a high-crystallized cubic Co0.5Cu0.5−xZnxFe2O4 with rod-like structure is obtained when the precursor is calcined at 800°C in air for 3 h. The lattice parameters increase with the increase of Zn2+ additional amount, attributed to the larger ionic radius of the substituted ion Zn2+ than Cu2+ ionic radius. Zn2+ substitution can improve the magnetic properties of Co0.5Cu0.5−x ZnxFe2O4. Co0.5Cu0.4Zn0.1Fe2O4 obtained at 800°C has the highest specific saturation magnetization (73.7 ± 0.9 emu/g) and magnetic moment (3.13 ± 0.04 B.M.). © 2016 The Minerals, Metals & Materials Society

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