Variation of magnetic properties with different annealed temperatures in the Ni_3[Fe(CN)_6]_2ㆍXH_2O

M. Liu,X.F. Bian,Y.F. Xia,Z. Bao,H.S. Wu,M.X. Xu 한국물리학회 2011 Current Applied Physics Vol.11 No.3

Molecular magnet nickel(II) hexacyanoferrate(III) powder Ni_3[Fe(CN)_6]_2ㆍXH_2O was prepared by coprecipitation method. The coprecipitated powder was annealed in vacuum at different temperatures of 140,and 160 ℃. Water molecules contained in Prussian blue analogues were removed by heating. The annealing of Ni^II ferricyanide induced an inner charge transfer from Ni^II towards Fe^III to form the mixed valence system Ni(II) Ni(III) ferri-ferro-cyanide. Variation of magnetic properties with different annealed temperatures was studied by elemental analysis, powder X-ray diffraction, transmission electron microscopy, Fourier transform infrared, and Mössbauer and magnetization measurements. The differences in magnetic phase transition temperature, coercivity, remanence and effective magnetization are studied. Differences in magnetic properties may be attributed to a partial charge transfer from Ni^II to Fe^III.

High-efficiency p–i–n organic light-emitting diodes with a novel n-doping electron transport layer

Wei Xu,M.A. Khan,Yu Bai,X.Y. Jiang,Z.L. Zhang,W.Q. Zhu 한국물리학회 2009 Current Applied Physics Vol.9 No.4

We demonstrate p–i–n organic light-emitting diodes (OLEDs) incorporating an n-doping transport layer which comprises 8-hydroxy-quinolinato lithium (Liq) doped into 4'7-diphyenyl-1,10-phenanthroline (Bphen) as ETL and a p-doping transport layer which includes tetrafluro-tetracyano-quinodimethane (F4-TCNQ) doped into 4,4',4''-tris(3-methylphenylphenylamono) triphenylamine (m-MTDATA). In order to examine the improvement in the conductivity of transport layers, hole-only and electron-only devices are fabricated. The current and power efficiency of organic light-emitting diodes have been improved significantly after introducing a novel n-doping (Bphen: 33 wt% Liq) layer as an electron transport layer (ETL) and a p-doping layer composed of m-MTDATA and F4-TCNQ as a hole transport layer (HTL). Compared with the control device (without doping), the current efficiency and power efficiency of Device C (most efficient) is enhanced by approximately 51% and 89%, respectively, while driving voltage is reduced by 29%. This improvement is attributed to the improved conductivity of the transport layers that leads to the efficient charge balance in the emission zone. We demonstrate p–i–n organic light-emitting diodes (OLEDs) incorporating an n-doping transport layer which comprises 8-hydroxy-quinolinato lithium (Liq) doped into 4'7-diphyenyl-1,10-phenanthroline (Bphen) as ETL and a p-doping transport layer which includes tetrafluro-tetracyano-quinodimethane (F4-TCNQ) doped into 4,4',4''-tris(3-methylphenylphenylamono) triphenylamine (m-MTDATA). In order to examine the improvement in the conductivity of transport layers, hole-only and electron-only devices are fabricated. The current and power efficiency of organic light-emitting diodes have been improved significantly after introducing a novel n-doping (Bphen: 33 wt% Liq) layer as an electron transport layer (ETL) and a p-doping layer composed of m-MTDATA and F4-TCNQ as a hole transport layer (HTL). Compared with the control device (without doping), the current efficiency and power efficiency of Device C (most efficient) is enhanced by approximately 51% and 89%, respectively, while driving voltage is reduced by 29%. This improvement is attributed to the improved conductivity of the transport layers that leads to the efficient charge balance in the emission zone.

Highly Sensitive and Selective Detection of Dopamine at Poly(chromotrope 2B)-Modified Glassy Carbon Electrode in the Presence of Uric Acid and Ascorbic Acid

Li, X.B.,Rahman, Md.M.,Xu, G.R.,Lee, J.J. Pergamon Press 2015 ELECTROCHIMICA ACTA Vol.173 No.-

A highly sensitive and selective electrochemical method based on a poly(chromotrope 2B)-modified anodized glassy carbon electrode (PCHAGCE) was developed for the determination of dopamine (DA) in the presence of uric acid (UA) and ascorbic acid (AA). The PCHAGCE sensor exhibited excellent electron-mediating behavior towards the oxidation of DA in 0.1M phosphate buffer solution (PBS) (pH7.0). It was found that the electrocatalytic activity was significantly dependent on the charge status and molecular structure of the target molecules. Differential pulse voltammetry (DPV) measurements revealed oxidation signals for DA, UA, and AA that were well-resolved into three distinct peaks with AA-DA, DA-UA, and AA-UA peak potential separations (ΔE<SUB>p</SUB>) of 172, 132, and 304mV, respectively. A detection limit of 0.04+/-0.001μM (S/N=3) and a quantification limit (S/N=10) of 0.149+/-0.03μM were obtained for DA sensing in a linear range of 1 to 40μM in PBS (pH7.0) with a very high sensitivity of 1.522+/-0.032μA.μM<SUP>-1</SUP>. The DA concentrations in human urine samples were also successfully determined with recoveries of 94.0-98.0%. This approach provides a simple, easy, sensitive, and selective method to detect DA in the presence of AA and UA.

Simulation of Neutron irradiation Corrosion of Zr-4 Alloy Inside Water Pressure reactors by Ion Bombardment

Bai, X.D.,Wang, S.G.,Xu, J.,Chen, H.M.,Fan, Y.D. The Korean Vacuum Society 1997 Applied Science and Convergence Technology Vol.6 No.1

In order to simulate the corrosion behavior of Zr-4 alloy in pressurized water reactors it was implanted (or bombarded) with 190ke V $Zr^+\; and \;Ar^+$ ions at liquid nitrogen temperature and room temperature respectively up to a dose of $5times10^{15} \sim 8\times10^{16} \textrm{ions/cm}^2$ The oxidation behavior and electrochemical vehavior were studied on implanted and unimplanted samples. The oxidation kinetics of the experimental samples were measured in pure oxygen at 923K and 133.3Pa. The corrosion parameters were measured by anodic polarization methods using a princeton Applied Research Model 350 corrosion measurement system. Auger Electron Spectroscopy (AES) and X-ray Photoelectric Spectroscopy (XPS) were employed to investigate the distribution and the ion valence of oxygen and zirconium ions inside the oxide films before and after implantation. it was found tat: 1) the $Zr^+$ ion implantation (or bombardment) enhanced the oxidation of Zircaloy-4 and resulted in that the oxidation weight gain of the samples at a dose of $8times10^{16}\textrm{ions/cm}^2$ was 4 times greater than that of the unimplantation ones;2) the valence of zirconium ion in the oxide films was classified as $Zr^0,Zr^+,Zr^{2+},Zr^{3+}\; and \;Zr^{4+}$ and the higher vlence of zirconium ion increased after the bombardment ; 3) the anodic passivation current density is about 2 ~ 3 times that of the unimplanted samples; 4) the implantation damage function of the effect of ion implantation on corrosion resistance of Zr-4 alloy was established.

Analysis of the Magnetic Properties of RFe₁₁Ti and RFe₁₁TiH (R=Tb,Ho)

S. W. Xu,Y. Yan,H. M. Jin,X. F. Wang,W. Q. Wang,F. Su 한국자기학회 2003 Journal of Magnetics Vol.8 No.4

The values of crystalline-electric-field parameters A㎚ for RFe₁₁TiHx (R=Tb,Ho) (x=0,1) are obtained by fitting calculations to the magnetization curves along the crystal axes at 4.2 K and higher temperatures. The insertion of H element in RFe₁₁Ti significantly affects CEF parameters A㎚. By using exchange field 2μ_BHex derived by inelastic neutron scattering and fitted A㎚, the calculations reproduce the experimental curves well.

Polymorphism of Ghrelin Gene in Twelve Chinese Indigenous Chicken Breeds and Its Relationship with Chicken Growth Traits

C. C. Li,K. Li,J. Li,D. L. Mo,R. F. Xu,G. H. Chen,Y. Z. Qiangba,S. L. Ji,X. H. Tang,B. Fan,M. J. Zhu,T. A. Xiong,X. Guan,B. Liu 아세아·태평양축산학회 2006 Animal Bioscience Vol.19 No.2

A 2,656 bp fragment of chicken ghrelin gene was cloned and SNPs were detected by PCR-RFLP and Allele Specific PCR (ASP) in 12 Chinese indigenous chicken breeds and a commercial chicken population. The results showed that there were 23 base variations and an amino acid change (Gln->Arg) in cloned chicken ghrelin gene. Three SNPs were confirmed in 13 populations and associations between this gene and growth traits of Tibetan chicken (TC) and Recessive White chicken (RW) were investigated. The results of haplotype analysis revealed that 26 haplotype genotypes were composed of eight haplotypes. The results of x2 tests indicated that there were significant differences between genotypes or haplotype genotype frequencies in some of the breeds or sexes at 0.05 or 0.01 levels. The results of ANOVA revealed that there were significant differences between genotypes or haplotype genotypes on some growth traits of TC and RW chicken breeds at 0.05 or 0.01 levels. Multiple comparisons showed that there were significant associations between genotype CT at site 71 and some growth traits of two chicken breeds and between genotype AG at site 1,215 and body weight at 16 wk of two chicken breeds, and there was a significant association between haplotype genotype CAA/CAG and body weight and shank girth at 16 wk of two chicken breeds.

Chaperonins Facilitate KNOTTED1 Cell-to-Cell Trafficking and Stem Cell Function

Xu, X. M.,Wang, J.,Xuan, Z.,Goldshmidt, A.,Borrill, P. G. M.,Hariharan, N.,Kim, J. Y.,Jackson, D. American Association for the Advancement of Scienc 2011 Science Vol.333 No.6046

Lithium reaction mechanism and high rate capability of VS4-graphene nanocomposite as an anode material for lithium batteries

Xu, X.,Jeong, S.,Rout, C.,Oh, P.,Ko, M.,Kim, H.,Kim, M.,Cao, R.,Shin, H.,Cho, J. Royal Society of Chemistry 2014 Journal of Materials Chemistry A Vol.2 No.28

Effects of Dietary Fructooligosaccharide on Digestive Enzyme Activities, Intestinal Microflora and Morphology of Growing Pigs

Xu, Z.R.,Zou, X.T.,Hu, C.H.,Xia, M.S.,Zhan, X.A.,Wang, M.Q. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.12

One hundred and twenty-eight growing barrows (Jiaxing Black${\times}$Duroc${\times}$Landrace) at an average BW of 20.8 kg were allocated to four treatments for 42 days, each of which was replicated four times with eight pigs per replicate and used to investigate the effects of fructooligosaccharide (FOS) on digestive enzyme activities, intestinal microflora and morphology of growing pigs. The pigs received the same basal corn-soybean meal diet and FOS was added to the basal diet at 0, 2, 4, 6 g/kg diet at the expense of corn, respectively. As compared to control, supplementation with 4 and 6 g/kg FOS significantly improved average daily gain and feed efficiency. Addition of FOS enhanced the growth of Bifidobacterium and Lactobacillus, but inhibited Clostridium and Escherichia coli in the small intestinal and proximal colonic contents. Supplementation with 4 and 6 g/kg FOS significantly improved the activities of total protease, trypsin and amylase in the small intestinal contents. However, FOS had no significant effect on the activity of lipase in the small intestinal contents as well as the digestive enzymes in pancreas. Morphological measurement of jejunal mucosa did show response to consumption of FOS. Villus height and the villus height to crypt depth ratio at the jejunal mucosa were significantly higher with 4 and 6 g/kg FOS supplementation as compared to control.

Dynamics of kinetic geodesic-acoustic modes and the radial electric field in tokamak neoclassical plasmas

Xu, X.Q.,Belli, E.,Bodi, K.,Candy, J.,Chang, C.S.,Cohen, R.H.,Colella, P.,Dimits, A.M.,Dorr, M.R.,Gao, Z.,Hittinger, J.A.,Ko, S.,Krasheninnikov, S.,McKee, G.R.,Nevins, W.M.,Rognlien, T.D.,Snyder, P.B. International Atomic Energy Agency 2009 Nuclear fusion Vol.49 No.6

<P>We present edge gyrokinetic simulations of tokamak plasmas using the fully non-linear (full-<I>f</I>) continuum code TEMPEST. A non-linear Boltzmann model is used for the electrons. The electric field is obtained by solving the 2D gyrokinetic Poisson equation. We demonstrate the following. (1) High harmonic resonances (<I>n</I> > 2) significantly enhance geodesic-acoustic mode (GAM) damping at high <I>q</I> (tokamak safety factor), and are necessary to explain the damping observed in our TEMPEST <I>q</I>-scans and consistent with the experimental measurements of the scaling of the GAM amplitude with edge <I>q</I><SUB>95</SUB> in the absence of obvious evidence that there is a strong <I>q</I>-dependence of the turbulent drive and damping of the GAM. (2) The kinetic GAM exists in the edge for steep density and temperature gradients in the form of outgoing waves, its radial scale is set by the ion temperature profile, and ion temperature inhomogeneity is necessary for GAM radial propagation. (3) The development of the neoclassical electric field evolves through different phases of relaxation, including GAMs, their radial propagation and their long-time collisional decay. (4) Natural consequences of orbits in the pedestal and scrape-off layer region in divertor geometry are substantial non-Maxwellian ion distributions and parallel flow characteristics qualitatively like those observed in experiments.</P>