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STUDY OF PHASES IN U-10wt%Zr ALLOY BY neutron diffraction

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Acta Metallurgica Sinica(English Letters) 1995年第3期8卷 174-180页

作者： XIE Guoqiang YANG Jijian ZHANG Baisheng LI Wendan(China Institute of Atomic Energy, Beijing) China Inst of Atomic Energy Beijing China

U 10wt%Zr alloy has been analysed by neutron diffraction method to determine the constituent phases and their crystal *** collected diffraction data are processed using Rietveld' s profile technique (with program“ Fullprof ”). Four phases,α-U,δ, γand α Zr, in the alloy at room temperature and the corresponding volume fractions as well their structural parameters are obtained from the data analysis, For the δ-phase, a partially ordered unusual hexagonal structure of the modified C32(AlB2) type is confirmed.

关键词： U-10wt%Zr alloy neutron diffraction δ-phase

Influence of short chain ceramides and lipophilic penetration enhancers on the nano-structure of stratum corneum model membranes studied using neutron diffraction

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Frontiers of Chemical Science and Engineering 2013年第1期7卷 29-36页

作者： Annett SCHROETER Tanja ENGELBRECHT Reinhard H. H. NEUBERT Institute of Pharmacy Martin Luther University Halle-Wittenberg D-06120 Halle/Saale Germany

Oriented stratum corneum model lipid membranes were used to study the influence of the short chain ceramides （CER）[NP] and [AP] as well as the impact of the lipophilic penetration enhancer molecules oleic acid （OA） and isopropyl myristate （IPM） on the lipid nanostrueture. The influence of the enhancer molecules were studied using specifically deuterated OA and IPM and neutron diffraction. 2H NMR spectroscopy was used to study the impact of the ceramides＇ degree of order within the stratum corneum model lipid membranes. It was found that CER[NP] forms two very stable phases with high resistance against temperature increase. Phase B showed unusual hydration behavior as no water uptake of this phase was observed. The 2H NMR spectroscopic measurements showed that CER[NP] based ternary model system had a higher state of lamellar order in comparison to CER[AP] based lipid matrix. The studies confirmed that the short chain ceramides, particularly CER[NP], have a very high impact on the integrity of the Stratum comeum lipid bilayers. The penetration enhancer OA has not influenced the repeat distance of the model membrane based on CER[AP], and was not able to induce a phase separation in the investigated lipid matrix. However, a disorder and a fluidisation of the model membranes were observed when OA was incorporated. IPM showed the same effect but two phases （assigned as phase A and B） appeared, when IPM was used as penetration enhancer and incorporated into the model membrane. Furthermore, two arrangements of IPM were identified in phase A using deuterated IPM. A model of the nanostructure of the Stratum corneum lipid membranes is presented.

关键词： nano-structure of the stratum corneum cer-amide penetration enhancer model membrane neutron diffraction 2H NMR spectroscopy

neutron　diffraction　Study　on　Structure　of　α－LiIO_3　Single　Crystal　under　DC　Voltage

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Chinese Journal of Structural Chemistry 1995年第6期 11-14页

作者： Cheng Yu-Fen Yang Zhen Cheng Zhi-Xu Guo Li-Ping(China Institute of Atomic Energy,Beijing 102413)E.Legrand(SCK/CEN Boeretang 200 B-2400 Mol,Belgium)

A detailed investigation of anisotropy of neutron diffraction intensity enhancement observed in α-LiIO-3 single crystal under a DC field was carried out on a Four-Circle neutron Diffractometer installed at the BR2 reactor in Belgium and CIAE *** was found that the intensity increase must be ascribed to small displacements of oxygen and iodine atoms rather than the explanation which is only based on changes in the defect of the crystal structure,since the movement of lithium atom to interstitial sites or holes in the crystal may cause displacement of the other atoms.

关键词： neutron diffraction single crystal structure α-LiIO3

neutron diffraction STUDY ON R_2Fel_(17)N_x(R=Y,Dy,Nd)

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Acta Metallurgica Sinica(English Letters) 1993年第11期6卷 345-348页

作者： YANG Jilian ZHANC Baisheng DINC Yongfan China Institute of Atomic Engergy,Beijing,ChinaYANG Yingchang ZHANG Xiaodong Peking University,Beijing,ChinaPAN Shuming General Research Institute for Non-Ferrous Metals,Beijing,China associate professor,P.O.Box 275,Branch No.30,Beijing 102413,China

The N occupying sites and magnetic structures in R_2Fe_(17)N_x(R=Y,Dy,Nd)are de- termined by neutron *** effects of the site occupation of N on magnetic properties are discussed primarily.

关键词： neutron diffraction Curie temperature permanent magnet (Y Dy Nd)_2Fe_2N_x

STRUCTURAL REFINEMENT FOR Nd_2(Fe_(0.9)Si_(0.1))_(14) B FROM neutron diffraction MEASUREMENT

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Acta Metallurgica Sinica(English Letters) 1990年第4期3卷 297-299页

作者： YANG Jilian ZHANG Baisheng JIN Lan DING Yongfan YE Chuntar Institute of Atomic Energy,Beijing,China YANG Yingchang,KONG Linshu Associate Professor,P.O.Box 275-80,Beijing 102413,China

neutron diffraction measurements on Nd2(Fe0,Si0 ,)14B at room temperature and 77 K were performed. Data analysis using profile refinement was carried out. The results show that at room temperature Si atoms occupy preferentially 4c, 8j, and I6k2 sites, and the magnetic moments of bath Nd and Fe are parallel to C-axis. At 77 K, the site occupations remain unchanged as in room temperature, while the calculated Nd magnetic moment direction has an angular deviation of 37.8 ° from C-axis.

关键词： neutron diffraction Nd2(Fe09Si0 ,)4B magnetic moment

X-Ray and neutron diffraction Studies on Thermal Parameters of Thalous Bromide

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Journal of Materials Science & Technology 2003年第2期19卷 189-190页

作者： J.Bashir R.T.A.Khan T.Ikeda KenichiOhshima PakistanInstituteofNuclearScience&Technology P.O.NiloreIslamabadPakistan InstituteofMaterialsSciences UniversityofTsukubaTennodai1-1-1Tsukuba-ShiIbaraki305Japan

Thermal parameters of TIBr were determined using both X-ray and neutron diffraction techniques. The data was analysed by Rietveld profile refinement procedure. From the neutron diffraction data, due to weak odd-order reflections, it was not possible to determine the individual thermal parameters. TheX-ray diffraction measurements yielded BT1=0.296(5) nm2 and BBr=0.162(5) nm2. The overall isotropic value, B was 0.252(7) nm2 which is in good agreement with B=0.230(8) nm2 obtained from present neutron diffraction measurements. The present values are also in good agreement with theoretical estimates obtained from the shell models.

关键词： Thallium bromide Temperature factors Debye temperature Rietveld refinement neutron diffraction X-ray diffraction

Crystallographic and magnetic structures ofPr6Fe13Ge studied by powder neutron diffraction

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Chinese Physics B 2004年第6期13卷 918-923页

作者：王芳卫张泮霖沈保根严启伟 StateKeyLaboratoryofMagnetism InstituteofPhysicsandCentreforCondensedMatterPhysicsChineseAcademyofSciencesBeijing100080China

Crystallographic and magnetic structures of Pr6Fel3Ge have been investigated by high-resolution powder neutron diffraction in the temperature range of 10-300 K. The magnetic structure consists of ferromagnetic Pr6Fe13 slabs that alternate antiferromagnetically, along c, with the next Pr6Fe13 slab separated by a non-magnetic Ge layer. The magnetic moments lie within the ab-planes. The propagation vector of this structure is k=(001) with respect to the conventional reciprocal lattice of the Ⅰ-centred structure. However, the temperature-dependence of neutron-scattering intensity of the (110) Bragg peak, very similar to the temperature-dependent magnetization measured by SQUID magnetometer,indicates that a small c-axis ferromagnetic component should be added to the above antiferromagnetic model.

关键词： neutron diffraction magnetic configuration Pr6Fel3Ge

neutron diffraction Study on the Magnetic Structure of 153EuMnO3-δ: One Way to Assess the Magnetic Structure of EuMnO3-δ

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Research and Application of Materials Science 2020年第2期2卷 58-64页

作者： Xing MA Muhammad Asim FARID Jian LI Aimei YANG Guobao LI Fuhui LIAO Laijun LIU Jianhua LIN Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871P.R.China College of Materials Science and Engineering Guilin University of TechnologyGuilin 541004P.R.China Department of Chemistry Division of Science and TechnologyUniversity of Education Lahore 54770Pakistan

Owing to the strong neutron absorption of 151Eu,151Eu free 153EuMnO3-δhas been synthesized to collect the neutron diffraction data for analyzing the magnetic structure of EuMnO3-δ.The obtained neutron diffraction data of 153EuMnO3-δindicates that the magnetic diffraction peaks corresponding to cAAFM(canted A-type antiferromagnetic)phase can be observed,but the magnetic diffraction peaks corresponding to expected ICAFM(incommensurate antiferromagnetic)phase may be too weak to be observed.

关键词： Magnetic structure neutron diffraction 153EuMnO3 Perovskite

neutron Back-and Front-Face Bragg diffraction on a Thin Si Single Crystal Excited by Ultrasound

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Journal of Modern Physics 2015年第1期6卷 37-45页

作者： E.Raitman V.Gavrilov D.Mjasischev Ju.Ekmanis A.Hoser T.Hoffmann Institute of Physical Energetics RigaLatvia Helmholtz-Zentrum BENSCBerlinGermany

In this research project, we measured and analyzed the spatial distribution of neutron beam Bragg diffracted from the front- and back-faces of thin Si single crystal undergoing on ultrasound excitation. For the perfect crystal, it is shown that when the acoustic wave amplitude is increased, the front-face peak position remains unchanged and its value grows linearly. The values of ultrasound wave amplitude were determined. The back-face peak becomes asymmetric and tends to disappear. New types of Pendellosung fringes in the center of the diffraction profiles were observed at the first time. It is supposed that in the perfect crystal this effect may be due to the appearance of the new “sonic” extinction length, depending on the amplitude of the ultrasonic wave. Thus, it leads to the new interference interactions between neutron wave and ultrasonic phonons. It is established that within the framework of the dynamical theory of the neutron scattering, some asymptotic models valid for the case of Laue geometry as well as Kato’s quasi-classical approximation can be applied in the case of Bragg geometry also. Good agreement between experimental data and the theory has been obtained.

关键词： neutron diffraction Ultrasound Pendellosung