Time filter

Source Type

Ding Y.,Wuhan University | Yuan C.,Wuhan University of Science and Technology | Wang Z.,Wuhan University | Liu S.,Wuhan University | And 5 more authors.
Applied Physics Letters | Year: 2014

Chromium dioxide (CrO2) is an ideal material for spin electronic devices since it has almost 100% spin polarization near Fermi level. However, it is thermally unstable and easily decomposes to Cr2O3 even at room temperature. In this study, we try to improve the thermal stability of CrO2 thin films by doping with Sn whose oxide has the same structure as CrO2. High quality epitaxial CrO2 and Sn-doped CrO2 films were grown on single crystalline TiO2 (100) substrates by chemical vapor deposition. Sn4+ ions were believed to be doped into CrO2 lattice and take the lattice positions of Cr4+. The magnetic measurements show that Sn-doping leads to a decrease of magnetocrystalline anisotropy. The thermal stabilities of the films were evaluated by annealing the films at different temperatures. Sn-doped films can withstand a temperature up to 510 °C, significantly higher than what undoped films can do (lower than 435 °C), which suggests that Sn-doping indeed enhances the thermal stability of CrO2 films. Our study also indicates that Sn-doping may not change the essential half metallic properties of CrO2. Therefore, Sn-doped CrO2 is expected to be very promising for applications in spintronic devices. © 2014 AIP Publishing LLC. Source

Peng M.,Wuhan University | Qin S.,Wuhan University | Qin S.,South-Central University for Nationalities | Jia H.,Wuhan University | And 4 more authors.
Nano Research | Year: 2016

A novel self-delivered prodrug system was fabricated for tumor-targeting therapy. In this nanosystem, the Arg-Gly-Asp-Ser (RGDS) tetrapeptide was used to improve the therapeutic index to integrin-overexpressing tumor cells. The antitumorous drug camptothecin was further appended to the ε-amino group of lysine by 20-O-succinyl linkage and controllably released via hydrolytic cleavage. Prodrug molecules self-assembled into fibrillar nano-architectures and achieved the capability of self-delivery after being injected subcutaneously into mice. Introduction of hydrophobic myristic acid favored the self-assembly and enhanced the cellular internalization of the prodrugs. In vitro and in vivo studies demonstrated that the self-assembled nanofibers could effectively target integrinoverexpressing tumorous cells and inhibit tumor growth via RGD-mediated specific targeting. Therefore, the traditional idea that fibrillar structures hold low therapeutic efficacy due to poor cell uptake can be challenged. [Figure not available: see fulltext.] © 2016, Tsinghua University Press and Springer-Verlag Berlin Heidelberg. Source

Lu X.-H.,Hubei University | Sun Y.-W.,Hubei University | Wei X.-L.,Hubei University | Peng C.,Hubei University | And 2 more authors.
Catalysis Communications | Year: 2014

Different from any other catalytic systems containing transition metals and additives, sodium hydroxide itself was found to be a unique and effective catalyst for the solvent-free synthesis of the secondary amines via the N-alkylation of amines with alcohols. For the reaction of aniline with benzyl alcohol, 99.6 mol% conversion of aniline and 99.5% selectivity of the product were achieved under optimal conditions. Also, high conversion and selectivity could be acquired for the N-alkylations of various amines with alcohols, implying the universality of this methodology. Mechanistic studies revealed that this novel reaction most possibly proceeds with a base-catalyzed mechanism. © 2014 Elsevier B.V. Source

Chen X.,Huazhong University of Science and Technology | Chen X.,Hubei University | Xiao J.,Hubei University | Yao J.,Hubei University | And 4 more authors.
Ceramics International | Year: 2014

Single-phase Bi4NdTi3Fe0.7Ni 0.3O15 polycrystalline samples were synthesized following a multicalcination procedure. The sample exhibited multiferroic property at room temperature, which was demonstrated by the ferroelectric (2Pr=8.52 μC/cm2, 2Ec=89 kV/cm at applied electric field 110 kV/cm) and magnetic (2Mr=388 m emu/g, 2Hc=689 Oe at applied magnetic field 1.04 T) hysteresis loops. More importantly, magnetoelectric coupling effect is observed from measurements of electrical properties not only under small but also under large electric signal when an external magnetic field is applied. The present results suggest a new candidate for a room temperature multiferroic material with magnetoelectric coupling effect. © 2013 Elsevier Ltd and Techna Group S.r.l.All rights reserved. Source

Zhou D.,Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials | Tang B.,Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials | Lu X.-H.,Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials | Wei X.-L.,Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials | And 2 more authors.
Catalysis Communications | Year: 2014

Selective oxidation of alkenes with air to corresponding epoxides was performed over simple ion-exchanged Co-MOR and Co-5A. Among all transition metal ions-exchanged M-zeolites, both Co-MOR and Co-5A exhibited the highest activity at 363 K. Notably, for the epoxidation of styrene, α-pinene, α-methyl styrene and cyclooctene, Co-MOR obtained higher conversions than Co-5A, in agreement with the difference of pore sizes of both zeolitic materials. Recycling and control tests showed high durability of Co-MOR as a heterogeneous catalyst in our catalytic system. © 2013 Elsevier B.V. Source

Discover hidden collaborations