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Investigation on the 773 K isothermal section of La-Fe-Sn ternary systems by X-ray powder diffraction

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Rare Metals 2010年第6期29卷 567-571页

作者： CHEN Xiang ZHUANG Yinghong CHEN Yungui Key Laboratory of Nonferrous Metal and New Processing Technology of Materials (Ministry of education of china) Guangxi University Nanning 530004 China Department of physics and electronic Information engineering Neijiang Teachers College Neijiang 641002 China Department of Metallic Materials engineering Sichuan University Chengdu 610065 China

The 773 K isothermal section of the La-Fe-Sn ternary system was investigated and constructed by X-ray powder diffraction（XRD）.The existence of two reported ternary intermetallic compounds,La6Fe13Sn and La3FeSn6,is confirmed in this *** with other R-Fe-Sn phase diagrams（R = Pr and Sm）,the binary alloys Fe3Sn and Fe5Sn3 are not *** compound Fe3Sn2 was observed from the XRD pattern of Fe3Sn2 samples,but it is not an equilibrium phase at 773 K and decomposes into Fe and FeSn phases completely for a longer heat treated *** to now,the crystal structure data of La2Sn3 has not been reported,so the X-ray pattern of La2Sn3 was only *** phase relationship for this compound was drawn by a dotted line.

关键词： intermetallics quenching phase diagrams X-ray diffraction.

Stochastic bi-resonance induced by external noise for Ca^2+ signaling in hepatocytes

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Science china Chemistry 2005年第4期48卷 286-291页

作者： ZHANG Jiqian1,2,HOU Zhonghuai1 & XIN Houwen1 1.Department of Chemical physics,university of Science and Technology of china,Hefei 230026,china 2.college of physics and electronic Information,Anhui Normal university,Wuhu 241000,china 1. Department of Chemical physics University of Science and Technology of China 230026 Hefei China 2. college of physics and electronic Information Anhui Normal University 241000 Wuhu China

The influence of external noise on intracellular Ca2+ oscillations dynamics in a single cell of rat hepatocytes is *** coherence of noise-induced intracellular Ca2+ oscillations reached two maxima for multiple external noise intensity,indicating the occurrence of external noise stochastic bi-resonance (SBR).This phenomenon is compared with our previous result that was induced by internal ***,the deterministic bifurcation character of the system was also discussed.

关键词： stochastic bi-resonance, environment fluctuation, calcium oscillations.

New ternary compound La_8Al_(13)Sn_3

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Rare Metals 2009年第5期28卷 491-493页

作者： HE Wei XIA Xiuwen ZHANG Jiliang HUANG Jinli LIU Yixin Key Laboratory of Nonferrous Metal Materials and New Processing Technology （Ministry of education） College of Materials Science and Engineering Guangxi University Nanning 530004 China Department of physics and electronic Information Science Guangxi Teachers Education University Nanning 530023 China

A new ternary compound La8Al13Sn3 was synthesized and studied by means of X-ray powder diffraction technique. The compound La8Al13Sn3 crystallizes in a hexagonal AlB2-type structure with space group P6/mmm （No. 191） and the lattice parameters a = 0.44919（1） nm and c = 0.43835（1） nm. The Smith and Snyder figure of merit for index, FN, is F30 = 197.3（30）. The Rietveld refinement for the crystal structure of the compound was carried out successfully. The liability R-factors of Rietveld refinement are Rp = 0.114 and Rwp = 0.148. The compound La8Al13Sn3 decomposes into LaAl2 with cubic structure and space group Fd 3m （227）, LaAl3 with hexagonal structure and space group P63/mmc （194）, and Sn at 720°C.

关键词： crystallography X-ray diffraction Reitveld method rare earth compounds

Bloch constant of holomorphic mappings on the unit polydisk of C^n

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Science china Mathematics 2008年第4期51卷 652-659页

作者： WANG JianFei~(1+) LIU TaiShun~2 1 college of Mathematics and physics Information engineering Zhejiang Normal university Jinhua 321004,china 2 Department of Mathematics Huzhou teachers college Huzhou 313000 china college of Mathematics and physics Information Engineering Zhejiang Normal University Jinhua China Department of Mathematics Huzhou Teachers College Huzhou China

In this paper,we give a definition of Bloch mappings defined in the unit polydisk D^n, which generalizes the concept of Bloch functions defined in the unit disk *** is known that Bloch theorem fails unless we have some restrictive assumption on holomorphic mappings in several complex *** shall establish the corresponding distortion theorems for subfamiliesβ(K)andβ_(loc)(K) of Bloch mappings defined in the polydisk D^n,which extend the distortion theorems of Liu and Minda to higher *** an application,we obtain lower and upper bounds of Bloch constants for various subfamilies of Bloeh mappings defined in D^*** particular,our results reduce to the classical results of Ahlfors and Landau when n=1.

关键词： Bloch constant Bloch mapping univalent ball critical point Julia lemma locally biholomorphic mapping Landau constant

Magnetocaloric effect of (Gd_(1-x)Nd_x)Co_2 alloys in low magnetic field

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Rare Metals 2008年第4期27卷 350-353页

作者： CHEN Xiang ZHUANG Yinghong YAN Jialin ZHOU Kaiwen LI Kefeng Key laboratory of the Ministry of education of china for Nonferrous Metal Materials and New Processing Technology Guangxi University Nanning 530004 China Department of physics and electronic Informational engineering Neijiang Teachers College Neijiang 641002 China

The phases and magnetocaloric effect in the alloys （Gd1-xNdx）Co2 with x = 0, 0.1, 0.2, 0.3, and 0.4 were investigated by X-ray diffraction analysis and magnetization measurement. The samples are single phase with a cubic MgCu2-type structure. The To decreases obviously with increasing Nd content from 404 K of the alloy with x = 0 to 272 K of the alloy with x = 0.4; forx = 0.3, the To is 296 K, which is near room temperature. In the samples （Gd1-xNdx）Co2 with x = 0.0, 0.1, 0.2, 0.3, and 0.4, the maximum magnetic entropy change is 1.471, 1.228, 1.280, 1.381 and 1.610 J·kg^-1·K^-1, respectively, in the applied field range of 0-2.0 T. The results of Arrott plots confirmed that the transition type were second order magnetic transition forx = 0, 0.3, and 0.4.

关键词： magnetic refrigeration materials magnetocaloric effect magnetic entropy change phase transition

Modulation on the collective response behavior by the system size in two-dimensional coupled cell systems

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Science china(physics,Mechanics & Astronomy) 2006年第3期49卷 304-312页

作者： ZHANG Jiqian1, SHEN Chuansheng1,2 & CUI Zhifeng1 1. college of physics and electronic Information, Anhui Normal university, Wuhu 241000, china 2. Department of educational Technology, Anqing teachers college, Anqing 246011, china college of physics electronic Information Anhui Normal University Wuhu 241000 China Department of educational Technology Anqing Teachers College Anqing 246011 China

By the intracellular calcium ionic minimal model proposed by Berridge, we investigated the collective response of two-dimensional (N×N) coupled cell systems to the external stimulation using numerical simulation methods. With a coupled intensity fixed and an appropriate coupled cell number chosen, the kinetic system size resonance was discovered. At the same time, it was found that the system size responding to the external stimulation for different coupled intensities transferred too, especially when the coupled intensity increased, the range of the corresponding system size extended. These phe- nomena illustrate that the coupled cell number and the coupled intensity can play con- structive roles in noisy coupled systems, by which the biology system would probably improve its capability to respond to the external stimulation.

关键词： cell coupling,collective response,system size resonance

Accurate studies on the full vibrational energy spectra and molecular dissociation energies for some electronic states of N_(2)molecule

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Science china(physics,Mechanics & Astronomy) 2005年第4期48卷 385-398页

作者： REN Weiyi1,2, SUN Weiguo1, HOU Shilin3 & FENG Hao4 1. Institute of physics, college of Chemical engineering, Sichuan university, Chengdu 610065, china 2. Institute of Theoretical physics, Xihua Normal university, Nanchong 637002, china 3. Department of physics, china Oceanography university, Qingdao 266003, china 4. college of physics, Sichuan university, Chengdu 610065, china 1. Institute of physics College of Chemical Engineering Sichuan University 610065 Chengdu China 2. Institute of Theoretical physics Xihua Normal University 637002 Nanchong China 3. Department of physics China Oceanography University 266003 Qingdao China 4. college of physics Sichuan University 610065 Chengdu China

It is usually very difficult to directly obtain molecular dissociation energy De and all accurate high-lying vibrational energies for most diatomic electronic states using modern experimental techniques or quantum theories, and it is also very difficult to give accurate analytical expression for diatomic molecular dissociation energy. This study proposes a new analytical formula for obtaining accurate molecular dissociation energy based on the LeRoy and Bernstein’s energy expression in dissociation limit. A set of full vibrational energy spectra for some electronic states of N2 molecule are studied using the algebraic method (AM) suggested recently, and the corresponding accurate molecular dissociation energies are evaluated using the proposed new formula and high-lying AM vibrational energies. The results show that the AM spectra and the new theoretical dissociation energies agree excellently with experimental data, and thereby providing a new physical approach to generating accurate dissociation energies for electronic states of diatomic molecules.

关键词： vibrational energy, dissociation energy, nitrogen molecule, algebraic method.

Studies on the Relation between the Composition of Thermal Sensitive MnZn Ferrite and Curie Temperature

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Journal of Materials Science & Technology 2000年第2期16卷 209-210页

作者： Mengkui WANG (Department of physics, Jinzhou teachers college, Jinzhou 121003, china) Junyue WANG (Jinzhou Audio-Visual education Center, Jinzhou 121000, china) Ke SUN (Department of physics, Northeastern university, Shenyang 110006, china) Department of physics Jinzhou Teachers College Jinzhou 121003 China Jinzhou Audio-Visual education Center Jinzhou 121000 China Department of physics Northeastern University Shenyang 110006 China

Thermal sensitive MnZn ferrite is a kind of soft magnetic ferrite material with lower Curie temperature (Tc) and can be used to make many kinds of magnetic thermal sensitive sensors with high sensitivity. In this paper, the relation between the composition of thermal sensitive ferrite and TC was studied. It was found that TC changes linearly with ZnO extent when the content of Fe2O3 is fixed. Based on lots of experiments, an experimential formula to determine was given out.

关键词： Studies on the Relation between the Composition of Thermal Sensitive MnZn Ferrite and Curie Temperature ZnO

Exchange bias for ferromagnetic/antiferromagnetic bilayers with the uniaxial anisotropy being misaligned with the exchange anisotropy

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Science china(physics,Mechanics & Astronomy) 2009年第12期52卷 1885-1892页

作者： BAI YuHao1 & YUN GuoHong1,2 1 college of Physical Science and Technology,Inner Mongolia university,Hohhot 010021,china 2 Key Laboratory of physics and Chemistry of Functional Materials,college of physics and electronic Information,Inner Mongolia Normal university,Hohhot 010022,china 1. college of Physical Science and Technology Inner Mongolia University Hohhot 010021 China 2. Key Laboratory of physics and Chemistry of Functional Materials College of Physics and Electronic Information Inner Mongolia Normal University Hohhot 010022 China

Using the principle of minimal energy and S-W model,the exchange bias for ferromagnetic/antiferro-magnetic bilayers has been investigated when the uniaxial anisotropy is misaligned with the exchange anisotropy. According to the relation between the energy of the bilayer and the orientation of ferro-magnetic magnetization,it is found that the bilayer will be in the monostable state or bistable state when the external field is absent in the initial magnetization state. The monostable state or bistable state of the bilayer,which determines the angular dependence of exchange bias directly,is controlled by the competition between the exchange anisotropy and uniaxial anisotropy. When the applied field is parallel to the intrinsic easy axes and intrinsic hard axes,one of the switching fields of the hysteresis loop shows an abrupt change,while the other keep continuous by analyzing the magnetization reversal processes. Consequently,the exchange bias field and the coercivity will show a jump phenomenon. The numerical calculations indicate that both the magnitude and direction of the exchange anisotropy will significantly affect the angular dependence of exchange bias. The jump phenomenon of exchange bias is an intrinsic property of the bilayer,which is dependent on the interfacial exchange-coupling constant,the orientation of the exchange anisotropy,the thickness and uniaxial anisotropy constant of the ferromagnetic layer.

关键词： monostable state bistable state intrinstic easy axis intrinstic hard axis switching field