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Composition and structure of ceramic coatings prepared on pure titanium by alternating-current microarc oxidation

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Composition and structure of ceramic coatings prepared on pu...

International Symposium of Young Scholars on Mechanics and Material Engineering for Science and Experiments

作者： Wenbin Xue11^ Chao Wang1 U] Ruyi ChenI1>2. Zhiwei Deng Yongchun Lai Key laboratory for radiation Beam Technology and Materials Modification {2. of Low {3. Nuclear physics Beijing Normal University) Beijing 100875 china m Beijing radiation Center Beijing 100875 china Key laboratory for radiation Beam Technology and Materials Modification Institute of Low Energy Nuclear Physics Beijing Normal University Beijing 100875 China

ISBN: (纸本)1880132796

＜正＞ A ceramic oxide coating of 3.μm was prepared on TA2.pure titanium by alternating-current microarc oxidation in aluminate solution. Its microstructure and phase component were characterized by scanning electron microscopy, X-ray diffractometry, Raman spectroscopy. The Al, Ti, O concentration profiles across the coating were determined by energy dispersive spectroscope. The coating contains two layers, an outer layer and an internal layer. The outer layer is composed of a large amount of TiAl2.5 and a little rutile type TiO2.compounds. But the rutile content in the inner layer is much higher than in the outer layer while the TiAl2.5 content decreases obviously in the inner layer. All of these oxides derive from a rapid solidification of the local molten coating in microarc discharge zone.

关键词： Microarc oxidation pure titanium phase structure ceramic coating

Interpretation of the pre-edge X-ray absorption fine structures in MnO

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Nuclear Science and Techniques 2003年第3期14卷 153-156页

作者： LI Shu-Jun, HU Rong, HU Tian-Dou, XIE Ya-Ning, ZHANG Jing, TAO Ye, WU Zi-Yu (Beijing synchrotron radiation Facility,{2., the Chinese Academy of Sciences, Beijing 10003. Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, Via Enrico Fermi 40,1-00044 Frascati, Italy) Beijing synchrotron radiation Facility Institute of High Energy Physics the Chinese Academy of Sciences 北京 100039

The weak pre-edge features in the Mn AT-edge X-ray absorption near-edge structure (XANES) spectrum of manganese monoxide (MnO) were investigated by comparing experimental data with dipolar and quadrupolar cross-section calculations in the framework of multiple-scattering theory. We assign the first pre-edge feature to a direct quadrupolar transition from Is core state to 3. molecular orbitals of the central atom, e.g., the lowest in energy, due to the more effective attraction of the core hole. The second peak in this region arises unambiguously from the hybridization between p-orbitals of the central atom with higher-shell metal octahedral orbitals.

关键词： X-ray absorption fine structures X-ray absorption near-edge structure MnO

Experiment of X-ray Generations Using Laser-Compton Scattering at LINAC of SINAP

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原子核物理评论 2009年第S1期26卷 109-114页

作者： PAN Qiang-yan1,XU Wang1,LUO Wen1,3.FAN Gong-tao1,3.Yang Li-feng1,3.Fan Guang-wei1,3.LI Yong-jiang1,3.XU Ben-ji1,SHI Xiang-chun2.LIN Guo-qiang1, YAN Zhe1,XU Yi1,3.CHEN Jing-gen1,GUO Wei1,WANG Hong-wei1,WANG Cheng-bin1, XU Jia-qiang1,Ma Yu-gang1,CAI Xiang-zhou1, ZHAO Ming-hua1,SHEN Wen-qing1(1 Shanghai institute of Applied physics,Chinese Academy of Sciences,Shanghai 2.1800,{2. 2.Shanghai institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 2.1800,{2. 3.Graduate School of Chinese Academy of Sciences,Beijing 100049,{2.) Shanghai institute of Applied physics Chinese Academy of SciencesShanghai 201800China Shanghai institute of Applied physics Chinese Academy of SciencesShanghai 201800China Graduate School of Chinese Academy of Sciences Beijing 100049China

Laser Compton scattering(LCS) can generate X-rays or γ-rays with high brightness and easy controlled polarization by applying high-peak-power laser pulses to relativistic electron bunches. One of the most promising approaches to short pulsed X-ray sources is the laser {2. source. It is based on LCS between picoseconds relativistic electron bunches and picoseconds laser pulses. A project of Shanghai laser electron gamma source with LCS method has been proposed on Shanghai {2. radiation facility. Before that,a prototype has been developed in the beamline of the linear accelerator at the Shanghai institute of Applied physics,Chinese Academy of Sciences. The LCS experiment was carried out by using the 107 MeV,5 Hz,1 ns,0.1 nC electron bunches from the linear accelerator and the 18 ns,10 MW peak power,Nd∶YAG laser pulses. In this communication,we describe the details and report the first results of this experiment.

关键词： Compton scattering Nd∶YAG laser γ-ray source polarization

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Electromagnetic retarded interaction and symmetry violation of time reversal in high order stimulated radiation and absorption processes of light

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Science china(physics,Mechanics & Astronomy) 2008年第3期51卷 282-298页

作者： MEI XiaoChun Department of physics,Fuzhou University,Fuzhou 3.002.,china 1. Department of physics Fuzhou University Fuzhou 350025 China

It has been proved that when the retarded effect (or multiple moment effect) of radiation fields is taken into account,the high order stimulated radiation and stimulated absorption probabilities of light are not the same so that time reversal symmetry would be violated,though the Hamiltonian of electromagnetic interaction is still unchanged under time reversal. The reason to cause time reversal symmetry violation is that certain filial or partial transition processes of bound atoms are forbidden or cannot be achieved due to the law of {3. conservation and the special states of atoms themselves. These restrictions would cause the symmetry violation of time reversal of other filial or partial transition processes which can be actualized really. The symmetry violation is also relative to the asymmetry of initial states of bound atoms before and after time reversal. For the electromagnetic interaction between non-bound atoms and radiation field,there is no such kind of symmetry violation of time reversal. In this way,the current formula on the parameters of stimulated radiation and absorption of light with time reversal sym-metry should be revised. A more reliable foundation can be established for the theories of laser and nonlinear optics in which non-equilibrium processes are in-volved.

关键词： quantum mechanics stimulated radiation and absorption of light retarded interaction time reversal symmetry violation laser nonlinear optics non-equilibrium processes

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Effects of Current on energy transport of argon plasma in the cascaded arc

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Effects of Current on energy transport of argon plasma in th...

第十五届全国等离子体科学技术会议

作者： J.Zhang~1,P.Wang~1,F.Chen~2.W.Sun~1,X.Lv~2.P.He~2.F.Gou~(1,3.) 1Key {3. of radiation {2. and Technology(Sichuan University),Ministry of Education {3. of Nuclear Science and Technology,Sichuan University,Chengdu 610064,P.R.china 2.{3. of Plasma Surface Interactions,Guizhou University,55002.,Guiyang,P.R.china 3.FOM {3. for Plasma {2.,3.3. MN Nieuwegein,The Netherlands

In this study PIASIMO was used to investigate the effect of current on energy exchanging in argon plasmas produced in the cascaded arc,the currents of 3., 50,70,90 A were *** simulation results show that from the inlet to the outlet along the symmetry axis,the ohmic dissipation density *** increasing current,the ohmic dissipation density *** energy exchanging is contributed by elastic collisions near the *** the energy transferring by inelastic collisions increases and then *** increasing current,the energy transferring by inelastic collisions increases and reaches the maximum at the outlet.

关键词： cascaded arc non-LTE ohmic dissipation elastic inelastic

Assessment of Dust Aerosol Optical Depth and Shortwave Radiative Forcing over the Northwest Pacific Ocean in Spring Based on Satellite Observations

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Atmospheric and Oceanic Science Letters 2009年第4期 223-228页

作者： CHEN Lin 1,2.SHI Guang-Yu 1,ZHONG Ling-Zhi 3.and TAN Sai-Chun 1 1 State Key laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics,institute of Atmospheric {2.,Chinese Academy of Sciences,Beijing 10002.,{3. 2.Key laboratory of Radiometric Calibration and Validation for Environmental Satellites (KLRCV),National Satellite Meteorology Center,{3. Meteorological Administration (NSMC/CMA),Beijing,100081,{3. 3.State Key laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081,{3. State Key laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical FluidDynamics Institute of Atmospheric physics Chinese Academy of Sciences Beo＇ing 100029 China Key laboratory of Radiometric Calibration and Validation for Environmental Satellites （KLRCV） National Satellite Meteorology Center China Meteorological Administration （SMC/CMA） Beijing 100081 China State Key laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing 100081 China

Dust aerosol optical depth (AOD) and its ac-companying shortwave radiative forcing (RF) are usually simulated by numerical ***,by using 9 months of Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol product data in combination with Clouds and the Earth’s Radiant energy System Single Scanner Footprint (CERES/SSF) data,dust AOD and its shortwave RF were estimated over the cloud-free north-west (NW) Pacific Ocean in the springs of 2.04,2.05,and *** results showed that in this region,the mean dust AOD and its shortwave RF were 0.10 and 5.51 W m 2.*** order to validate the dust AOD de-rived by MODIS,results from the Goddard Global Ozone Chemistry Aerosol radiation and Transport (GOCART) model were also used *** correlation coefficient between the monthly averaged dust AOD derived by MODIS measurements and the model simulation results was approximately *** the estimates of the dust AOD and its shortwave RF obtained in this study are based mainly on satellite data,they offer a good reference for numerical models.

关键词： dust aerosols optical depth shortwave radiative forcing northwest Pacific satellite measurements

Molecular dynamics study on the structure I helium hydrate

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Progress in Natural Science:Materials International 2004年第11期 79-82页

作者： CHENG Wei, WU Hucai, YE Xiaoqin and ZHOU Hongyu*(Key laboratory in University for radiation Beam Technology and Materials Modification, {2. of Low {3. Nuclear physics, Beijing Normal University, Beijing 100875, china) KeylaboratoryinUniversityforradiationBeamTechnologyandMaterialsModification InstituteofLowEnergyNuclearPhysicsBeijingNormalUniversityBeijing100875China

A 3.8- water molecule structure I gas hydrate, encased by the number of helium (He) molecules ranging from two to twenty-two, are calculated by molecular dynamical simulations. The potential TIP4P (transferable intermolecular potentical with four sites) is used for water interactions and Lennard-Jones for He-He and He-water interactions. He molecules do not affect the water lattice and can stabilize the hydrate when their concentration is small. A trough signature of He encased is found at 80～90 meV in the phonon density of states. He molecules prefer to be more off-center in 5 12. 2.cages. Heavier isotope He are energetically favorable to be filled in cages.

关键词： molecular dynamics neutron scattering spectra helium hydrate.

DLC formation in C implanted PET

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DLC formation in C implanted PET

18th International Conference on high Pressure Science and Technology

作者： Wu Yuguang Zhang TongheKey laboratory in University for radiation Beam Technology and Material modification {2. of Low {3. Nuclear physics Beijing Normal University Beijing radiation Center Beijing

＜正＞In order to enhance the mechanical and electrical properties of the polymers, ion implantation techniques have been suggested [1-4]. Recent studies have shown that ion implantation is very effective for improving surface properties of polymers Polyethylene terephthalane （PET） has been modified with C ions attracted from a metal vapor arc source （MEVVA）. After implantation, sheet resistance decreased. The results from nano testing show that after C implantation, flexibility of implanted layer increases as shown in Fig.l. The Surface hardness is 12.3.times greater than that of PET, 2.times greater than stainless steel hardness （3.Pa）, the Modulus increases 2.6 times comparing with PET as shown in Table 1. The infrared absorption indicated that the bonds of carbon nano-particles and DLC nano-particles are detected. The PET has been strengthened by these dispersed nano-particles. The measurement results using nano hardness tester show that the surface hardness and modulus increase obviously. The surface structure has greatly changed. The TEM photo shows that the nano-particles were formed.

关键词： C implantation Tribological properties Nano particle Surface strengthening mechanism of polymer.

Structural phase transitions of tellurium nanoplates under pressure

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Chinese physics B 2015年第3期24卷 280-283页

作者：李超 Arfan Bukhtiar 沈希孔盼盼王伟鹏赵豪飞姚湲邹炳锁李延春李晓东刘景靳常青禹日成 Beijing National laboratory for Condensed Matter physics Institute of PhysicsChinese Academy of Sciences Beijing Key laboratory of Nanophotonics and Ultrafine Optoelectronic Systems Beijing Institute of Technology institute of high {2. {3. Chinese Academy of Sciences

In situ high-pressure angle dispersive x-ray diffraction experiments using synchrotron {2. on Te nanoplates were carried out with a diamond anvil cell at room temperature. The results show that Te-Ⅰ with a trigonal structure transforms to triclinic Te-Ⅱ at about 4.9 GPa, Te-Ⅱ transforms to monoclinic Te-Ⅲ at about 8.0 GPa, Te-Ⅲ turns to rhombohedral Te-Ⅳ at about 2..8 GPa, and Te-Ⅳ changes to body centered cubic Te-Ⅴ at 2..6 GPa. The bulk moduli B0 of Te nanoplates are higher than those of Te bulk materials.

关键词： tellurium nanoplates phase transition high pressure

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