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Journal of Rare Earths 2012年第2期30卷 142-145页

作者：周玲玲周洪庆邵辉朱海奎 college of Materials Science and Engineering Nanjing University of Technology

The Ba6-3xSm8＋2xTi18O54 （x=2/3） microwave dielectric ceramics were prepared by traditional solid sate reaction technique. The ex-periment was based on the Ba6-3xSm8＋2xTi18O54 （BST） microwave dielectric ceramics doped with a certain amount of Bi2O3, then the effects of BaxSr1-xTiO3 additives on the structure and microwave dielectric properties of Ba6-3xSm8＋2xTi18O54 ceramics were investigated using X-ray diffraction and scanning electron microscopy. In this study, the small amount substitution of Sr for Ba was effective for the microwave dielec-tric properties of BST, especially the τf could be tuned to near zero. The result showed that the BST possessed excellent dielectric properties when the addition of Bi2O3 and BaxSr1-xTiO3 was 1 wt.% respectively： εr=79.6, Q？f=10789 GHz, τf=-1.5 ppm/oC.

关键词： dielectric properties microstructure BaxSr1–xTiO3 rare earths

Regeneration of waste sintered Nd-Fe-B magnets to fabricate anisotropic bonded magnets

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Journal of Rare Earths 2015年第7期33卷 736-739页

作者：李现涛岳明 ZAKOTNIK Miha 刘卫强张东涛左铁镛 college of Materials Science and Engineering Beijing University of Technology

The waste sintered Nd-Fe-B magnets were regenerated as magnetic powders via manually crushing （MC） or hydrogen decrepitation （HD） to fabricate anisotropic bonded magnets. Effect of size distribution on the magnetic properties of the regenerated magnetic MC and HD powders was investigated. For the MC powders, as the particle size decreased, the remanence （Br） increased first, and then decreased again, while the coercivity （Hci） dropped monotonically. The powders with particle size in the range of 200-450μm possessed the best magnetic properties ofBr of 1.22 T and Hci of 875.6 kAJm. The corresponding bonded magnet exhibited magnetic properties ofBr of 0.838 T, Hci of 940.9 kA/m, and （BH）max of 91.4 kJ/m^3, respectively. On the other hand, the liD powders with particle size range of 200-450 μm bore the best magnetic properties Of Br of 1.24 T and Hci of 860.4 kA/m. Compared with magnetic properties of the waste magnet, the powders retained 93.9% of Br and 70.0% of Hci, respectively. The bonded magnet produced from HD powders possessed Br of 0.9 T, Hci of 841.4 kA/m, and （BH）max of 111.6 kJ/m^3, indicating its good potential in practical applications.

关键词： regeneration Nd-Fe-B magnet scraps hydrogen decrepitation anisotropic bonded magnets rare earths

Thermodynamics of a two-dimensional charged black hole in the geometric framework

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Chinese Physics B 2014年第10期23卷 60-63页

作者：韩亦文洪云 college of Computer Science Chongqing Technology and Business University

In this paper, we study the thermodynamic features of a two-dimensional charged black hole. Weinhold curvature and Ruppeiner curvature are explored as information geometry, respectively. Moreover, based on the Legendr... 详细信息

关键词： black hole thermodynamic curvature Legendre invariant

Study on phosphating treatment of aluminum alloy:role of yttrium oxide

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Journal of Rare Earths 2009年第3期27卷 469-473页

作者：张圣麟 college of Chemistry and Environmental Science Henan Normal University

Zinc phosphate coatings formed on 6061-Al alloy, after dipping in phosphating solutions containing different amounts of Y2O3（yttrium oxide）, were studied by scanning electron microscopy （SEM）, X-ray diffraction （XRD） and electrochemical measurements. Significant variations in the morphology and corrosion resistance afforded by zinc phosphate coating were especially observed as Y2O3 in phosphating solution varied from 0 to 40 mg/L. The addition of Y2O3 changed the initial potential of the interface between aluminum alloy substrate and phosphating solution and increased the number of nucleation sites. The phosphate coating thereby was less porous structure and covered the surface of aluminum alloy completely within short phosphating time. Phosphate coating was mainly composed of Zn3（PO4）2·4H2O （hopeite） and AlPO4（aluminum phosphate）. Y2O3, as an additive of phosphatization, accelerated precipitation and refined the gain size of phosphate coating. The corrosion resistance of zinc phosphate coating in 3% NaCl solution was improved as shown by polarization measurement. In the present research, the optimal amount of Y2O3 was 10-20 mg/L, and the optimal phosphating time was 600 s.

关键词： yttrium oxide zinc phosphate coating aluminum alloy nucleation agent accelerator rare earths

Investigation of coupled cobalt-silver nanoparticle system by plan view TEM

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Progress in Natural Science:Materials International 2012年第3期22卷 186-192页

作者： Daniel Fox Ruggero Verre Brendan J. O'Dowd Sunil K. Arora Colm C. Faulkner Igor V. Shvets School of Physics and CRANN Trinity College Dublin CRANN Advanced Microscopy Laboratory Trinity College Dublin

We present a transmission electron microscopy (TEM) investigation of a coupled cobalt and silver nanoparticle system. A plan view in situ lift-out method for preparing samples for TEM using the focused ion beam (FIB) microscope was used. This technique is used to prepare high quality TEM samples with site specificity in a short time and with a high success rate. We demonstrate the ability of the plan view sample preparation technique to provide information about an ordered system of nanoparticles which could not be observed using standard FIB cross sectioning of the sample. High resolution TEM and energy dispersive X-ray spectroscopy mapping of both cross sectional and plan view samples are presented, clearly showing the significant benefit of plan view TEM analysis for certain samples.

关键词： Focused ion beam Transmission electron microscopy Lift-out Co Ag Nanoparticle

Uniform YF_3 nanorods:Synthesis,luminescent properties and cytotoxicity study

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Journal of Rare Earths 2011年第11期29卷 1036-1039页

作者：吕蕴海李苑赵东张林飞钟声亮 college of Chemistry and Chemical Engineering Jiangxi Normal University

Uniform YF3 nanorods composed of nanoparticles were successfully prepared via a facile solvothermal method with ethanol as solvent and tetrabutyl ammonium fluoride（TBAF） as fluorine *** products were characterized with powder X-ray diffraction（XRD）,scanning electron microscopy（SEM） and transmission electron microscopy（TEM）.The nanorods were with diameters of ca.60 nm and lengths ranging from 200 to 350 ***3＋ and Tb3＋ doped YF3 nanorods were also prepared and their photoluminescence properties were *** study revealed that these YF3 based nanorods were biocompatible.

关键词： yttrium fluoride nanorods luminescent properties bio-application rare earths

Specific mode output from multimode fiber oscillators by designing rare earth doping profiles

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Chinese Physics B 2014年第9期23卷 232-237页

作者：王文亮黄良金冷进勇郭少锋姜宗福 college of Optoelectric Science and Engineering National University of Defense Technology

Based on rate equations, a theoretical model of a fiber oscillator with a multimode gain fiber was built. We studied the effect of the rare earth doping profile in the core on the output characteristics of the multimode fiber oscillator. The results indicated that a pure fundamental mode can be obtained by partly doping the core of the large mode area （LMA） ytterbium doped fiber （YDF） in the fiber laser. Furthermore, a sole specific high-order mode can also be implemented by tailoring the rare earth doping profile according to the simulations. The mode coupling effect was also taken into account in the model. In spite of the mode coupling effect, the specific mode was able to dominate in the output of the fiber laser by utilizing the designed LMA YDF.

关键词： fiber laser rare earth doping profile specific mode

The analytical potential energy function of flue gas SO_2(X^1A_1)

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Chinese Physics B 2012年第4期21卷 207-212页

作者：伍冬兰谢安东余晓光万慧军 college of Mathematics and Physics Jinggangshan UniversityJi'an 343009China

The equilibrium structure of flue gas SO2 is optimized using the density functional theory （DFT）/B3P86 method and CC-PV5Z basis. The result shows that it has a bent （C2v, X1A1） ground state structure with an angle of 119.1184°. The vibronic frequencies and the force constants are also calculated. Based on the principles of atomic and molecular reaction statics （AMIIS）, the possible electronic states and reasonable dissociation limits for the ground state of SO2 molecule are determined. The potential functions of SO and 02 are fitted by the modified Murrell-Sorbie＋c6 （M-S＋c6） potential function and the fitted parameters, the force constants and the spectroscopic constants are obtained, which are all close to the experimental values. The analytic potential energy function of the SO2 （X1A1） molecule is derived using the many-body expansion theory. The contour liues are constructed, which show the static properties of SO2 （XIA1）, such as the equilibrium structure, the lowest energies, the most possible reaction channel, etc.

关键词： flue gas SO2 analytical potential energy function many-body expansion theory

Conformal invariance and a kind of Hojman conserved quantity of the Nambu system

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Chinese Physics B 2011年第3期20卷 9-13页

作者：李燕方建会张克军 college of Physics Science and Technology China University of Petroleum

Conformal invariance and a kind of Hojman conserved quantity of the Nambu system under infinitesimal transformations are studied. The definition and the determining equation of conformal invariance of the system are presented. The necessary and sufficient condition under which the conformal invariance of the system would have Lie symmetry under infinitesimal transformations is derived. Then, the condition of existence and a kind of Hojman conserved quantity are obtained. Finally, an example is given to illustrate the application of the results.

关键词： conformal invariance Nambu system Hojman conserved quantity

Structural evolution-enabled BiFeO3 modulated by strontium doping with enhanced dielectric,optical and superparamagnetic properties by a modified sol-gel method

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Chinese Physics B 2023年第3期32卷 521-530页

作者： Sharon V S Veena Gopalan E Malini K A Department of Physics Vimala college Thrissur-9 KeralaIndia

Multiferroic(BFO)nanoparticles doped with strontium with the general formula Bi1-xSrx FeO3(x=0,0.3,0.5,0.7)were synthesized using a modified sol-gel auto-combustion *** structural,electrical,optical,and magnetic properties of the samples are *** structural analysis,carried out using the x-ray powder diffraction technique,shows a structural transition from rhombohedral(R-3c)to cubic(Pm-3m)for the doping amount of strontium(Sr)equal to x=*** analysis of the prepared samples were carried out using scanning electron microscopy(SEM).Frequency-dependent dielectric constant and ac conductivity were *** doped samples,with improved dielectric properties,can be used to fabricate different optoelectronic *** dielectric dispersion and broad relaxation were exhibited by all the ***–Cole plots were employed as an effective tool to study the dispersion parameters,namely,the optical dielectric constant,static dielectric constant,relaxation time,and spreading *** activation energy was calculated from the relaxation peaks and Cole–Cole plots,which were found to be compatible with each *** bandgap of the samples was calculated using diffuse reflectance spectral(DRS)*** and strong photoluminescence in the IR region was observed in the samples,similar to ZnO,which was reported for the first ***-temperature and low-temperature magnetization studies point towards the superparamagnetic nature of the samples,with an improvement in magnetic properties with *** antiferromagnetic behavior of bulk bismuth ferrite transforms to superparamagnetic in nature for both pure and Sr-substituted bismuth ferrite nanoparticles due to the close dimensions of crystallite size with magnetic domains leading to the break-down of the frustrated spin cycloidal moment.

关键词： multiferroics sol-gel process x-ray spectra optical and dielectric properties