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Up-conversion emissions of Er^(3+)-Yb^(3+) codoped Al_2O_3 nanoparticles by the arc discharge synthesis method

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science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 1043-1046页

作者： DONG Bin1, CAO BaoSheng1, FENG ZhiQing1, WANG XingJun2, LI ChengRen3 & HUA RuiNian4 1 school of science, Dalian Nationalities university, Dalian 116600, china 2 school of electronics Engineering and Computer science, Peking university, Beijing 100871, china 3 College of Physics and electronic technology, Liaoning Normal university, Dalian 116029, china 4 College of Life science, Dalian Nationalities university, Dalian 116600, china 1. school of science Dalian Nationalities University Dalian 116600 China 2. school of electronics Engineering and Computer science Peking University Beijing 100871 China 3. College of Physics and electronic technology Liaoning Normal University Dalian 116029 China 4. College of Life science Dalian Nationalities University Dalian 116600 China

The Er3+-Yb3+ codoped Al2O3 nanoparticles with an average particle size of about 50 nm have been synthesized by an arc discharge synthesis method. The green and red up-conversion emissions centered at about 526, 547 and 677 nm, corresponding respectively to the 2H11/2→4I15/2, 4S3/2→4I15/2 and 4 F9/2→4I15/2 transitions of Er3+, were detected by a 978-nm semiconductor laser diode excitation. The Annealing has evident effect on the up-conversion emissions of the samples: The red up-conversion emission is noticeable before annealing; however, the green up-conversion emission becomes predominant after annealing. The mixture of (Er,Yb)3Al5O12 and α-(Al,Er,Yb)2O3 phases is more favorable for green up-conversion emissions due to an enhancement of the ESA (I) of 4I11/2+a photon→4F7/2 and ET (III) of 2F5/2(Yb3+)+4I11/2(Er3+)→2F7/2(Yb3+)+4F7/2(Er3+) processes. The two-photon absorption up-conversion process is involved in the green and red up-conversion emissions. The results have proved that arc discharge synthesis is a new promising preparation technology for optical materials.

关键词： up-conversion Er3+-Yb3+ codoped Al2O3 arc discharge synthesis

Research of CRM Based on Customer Intelligence Engine

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Journal of electronic science and technology of china 2004年第3期2卷 98-103页

作者： HOU Lun, TANG Xiaowo (school of Management, university of electronic science and technology of china chengdu 610054 china) school of Management University of Electronic Science and Technology of China Chengdu 610054 China

The discipline of business intelligence addresses a broad range of functional activities from data mining and statistical analysis to predictive modeling and reporting, and customer intelligence is the actionable output from an intelligence eco-system. In order to focus enterprise's attention on their customers satisfaction in the customer relationship management and make CRM system run more efficiently, a new concept of customer intelligence engine(CIE) is proposed at first time in the paper, the architecture of CIE is structured, the trigger of CIE is defined and described, the CIE-based CRM eco-system is also discussed.

关键词： customer intelligence (CI) customer intelligence engine (CIE) business intelligence (BI) customer relationship management (CRM)

Anisotropic HDDR-treated Nd_2Fe_(14)B-type powder

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science china(Physics,Mechanics & Astronomy) 2010年第9期53卷 1590-1593页

作者： LIU Min1,3,HAN BaiPing2,3,HAN GuangBing3 & GAO RuWei3 1 Department of electronic science,Huizhou university,Huizhou 516007,china 2 College of Mathematical and physical sciences,Xuzhou Institute of technology,Xuzhou 221008,china 3 school of Physics,Shandong university,Jinan 250100,china 1. Department of electronic science Huizhou University Huizhou 516007 China3. School of Physics Shandong University Jinan 250100 China2. College of Mathematical and Physical Sciences Xuzhou Institute of Technology Xuzhou 221008 China

Effects of the wheel speeds v and disproportionation time during the SC-HDDR process on the properties of Nd-Fe-B magnetic powders are *** is found that the remanence Br,coercivity Hcj and energy products(BH)max of magnetic powders all first increase to the maximum at v=3 m/s,and then decrease with enhancing *** is attributed to the fact that the SC alloy flakes prepared by the wheel speed of 3 m/s display the optimized *** optimized SC alloy flakes without homogenizing treatment which carried out a short duration disproportionation treatment can prepare the evidently anisotropic *** prolonging disproportionation time,the alignment degree of anisotropy of magnetic powders gradually *** is due to the fact that a short duration disproportionation reaction is beneficial to the disproportionated microstructure displaying the lamella crystals,and the lamella disproportionated microstructure is helpful to the formation of *** results confirm that the anisotropic HDDR Nd-Fe-B magnetic powders prepared directly from the SC alloy flakes without homogenizing treatment can be obtained.

关键词： SC-HDDR process SC alloy flakes disproportionated microstructure anisotropic powders

3,4-oxo-isopropylidene-shikimic acid inhibits adhesion of polymorphonuclear leukocyte to TNF-α-induced endothelial cells in υitro

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Acta Pharmacologica Sinica 2004年第2期 120-124页

作者： Yi MA, Jian-ning SUN2, Qiu-ping XU, Zi-li YOU3, Ya-jian GUO Department of Pharmacology, Beijing university of Chinese Traditional Medicine, Beijing 100102 3school of Life science and technology, university of electronic science and technology of china, chengdu 610054, china

AIM: To examine the effect of 3,4-oxo-isopropylidene-shikimic acid (ISA) on human polymorphonuclear leuko- cyte (PMN) adhesion to human umbilical vein endothelial cells (HUVEC) and explore its mechanism. METHODS: Adhesion of PMN to HUVEC was measured by rose bengal staining assay. Cell-ELISA and RT-PCR methods were used to examine the expression of adhesion molecules ICAM-1. Cell viability was detected with MTT assay. RESULTS: ISA (1-100 μmol/L) effectively reduced PMN adhesion to TNF-α-induced HUVEC with the inhibitory rate from 17.2 % to 53.5 %, and exerted no effect on PMN adhesion to normal HUVEC. Adhesion molecule ICAM-1 surface protein and mRNA expression induced by TNF-α (400 kU/L) were significantly inhibited by ISA. In addition, the cell viability of HUVEC was unchanged 48 h after treatment with ISA. CONCLUSION: ISA inhibited TNF-α-stimulated PMN-HUVEC adhesion and expression of ICAM-1.

关键词： oxo-isopropylidene-shikimic acid adhesions vascular endothelium neutrophils intercellular adhesion molecule-1

physical Property Influence on Foaming Index of Refining Slag

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 8-10,14页

作者： Lin Di Ping Wang Jie Fu (Metallurgy school, university of science and technology Beijing, Beijing 100083, china) Univ of science and technology Beijing Beijing China

The foaming indexes of a group of refining slag were measured. The refining slag with better foaming ability was chosen,its composition (mass frachon in %) is CaO, 53.25, SiO2, 17.75, MgO, 9; Al2O3, 15 and CaF2, 5. The relationship between slag foaming index and physical properties of the slag was obtained by dimensional analysis, and the expression indicates that viscosity of slag is the most important factor which influences foamng index. The influence sequence of slap composition on foaming index was also obtained as follows: CaF2→MgO→Al2O3→ B (CaO/SiO2).

关键词： secondary refining submerged arc slag dimensional analysis

Design and Synthesis of Ti-ZrO_2 Functionally Graded Materials

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Journal of university of science and technology Beijing 2001年第1期8卷 48-52页

作者： Lidong Teng, Fuming Wang, Wenchao Li Metallurgy school, university of science and technology Beijing, Beijing 100083, china Univ Sci & Technol Beijing Met Sch Beijing 100083 Peoples R China

Functionally graded materials (FGMs) based on titanium-zirconia system have been prepared by powder metallurgical method. The graded interlayer number and the compositional distribution have been designed by elastic finite element method. The interfacial microstructure between layers, the combining state of phases between Ti and ZrO2 have been investigated by means of XRD (X-ray diffraction), SEM (scanning electron microscope), EDS (energy dispersive spectrometer) and so on. The co-existing region of Ti and ZrO2 has been determined by thermodynamic calculation to control the sintering atmosphere. The experimental results show that the joint between Ti and ZrO2 phases is physical in this composite and ZrO2 mainly exists as tetragonal phase. The microstructure of Ti-ZrO2 system FGM exhibits a transition from a zirconia particle dispersion in a titanium matrix to an inverse dispersion of titanium in zirconia. The gradient structure of titanium and zirconia can relieve thermal stress.

关键词： Ti-ZrO2 system functionally graded material thermodynamic analysis finite element method

Sidelobe reduction based on spectrum reshaping in microwave imaging

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science china(Information sciences) 2011年第1期54卷 204-212页

作者： WANG HuaiJun,SU Yi,XU HongBo & ZHU YuTao school of electronic science and Engineering,National university of Defense technology, Changsha 410073,china 1. school of electronic science and Engineering National University of Defense Technology Changsha 410073 China

Sidelobe artifacts are a common problem in image reconstruction from finite-extent Fourier data obtained by microwave imaging *** order to enhance the image quality,sidelobe reduction must be *** the sidelobe reduction in microwave imaging as the research subject,this paper presents Fourier imaging technique *** the point spread function is obtained through Fourier inversion of rectangular spectral support data and the changing effect of sidelobe direction due to reshaping spectral support is *** reshaping makes that the sidelobes of two Fourier images do not *** on the idea of separating sidelobes from mainlobe,a nolve method that reduces sidelobe levels while maintaining the imaging resolution is *** performance of this method is ***,the simulated and measured data of typical microwave imaging systems such as synthetic aperture radar(SAR),inverse synthetic aperture radar(ISAR)and real aperture radar are used to demonstrate the validity of the proposed method.

关键词： microwave imaging Fourier imaging sidelobe reduction spatial spectrum point spread function

Synthesis of TiN/AlON composite ceramics

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Journal of university of science and technology Beijing 2003年第1期10卷 49-53页

作者： Xidong Wang, Lichun Gao, Guobao Li, and Wenchao LiDepartment of physical Chemistry, university of science and technology Beijing, Beijing 100083, china Dept. of Phys. Chem. Univ. of Sci. and Technol. Beijing Beijing 100083 China

The synthesis process of TiN/AlON composite ceramics was studied, the thermodynamics, mechanical properties and micro-structures of TiN/AlON have also been investigated. The TiN/AlON composite ceramics has been synthesized by both hot-pressing and pressureless sintering. The characterizations of the material synthesized were analyzed with XRD (X-ray diffraction) and TEM (transmission electronic microscope). The density and toughness strength of TiN/AlON are 3.57g/cm3 and 4.74MPa.m1/2, respectively. The bending strength was measured at both room temperature and high temperatures and the results are 399 MPa (room temperature), 406 MPa (1 073 K), 417 MPa (1 273 K) and 323 MPa (1 573 K). Pattern Recognition (PR) and Artificial Neural Network (ANN) were used to optimize the parameters and to predict the expected values. A proper parameter for pressureless sintering of TiN/AlON has been obtained and testified, the parameters are temperature (1 978 K), AlN / (AlN + Al2O3) ratio (0.22), MgO (4.7%) and TiO2 (7.2%).

关键词： synthesis TiN AlON composite ceramics

Design of a re-entrant double-staggered ladder circuit for V-band coupled-cavity traveling-wave tubes

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Chinese Physics B 2012年第7期21卷 291-297页

作者：刘洋徐进赖剑强许雄沈飞魏彦玉黄民智唐涛宫玉彬 National Key Laboratory of science and technology on Vacuum electronics School of Physical ElectronicsUniversity of Electronic Science and Technology of China

The re-entrant double-staggered ladder slow-wave structure is employed in a high-power V-band coupled-cavity traveling-wave tube. This structure has a wide bandwidth, a moderate interaction impedance, and excellent thermal dissipation properties, as well as easy fabrication. A well-matched waveguide coupler is proposed for the structure. Combining the design of attenuators, a full-scale three-dimensional circuit model for the V-band coupled-cavity traveling- wave tube is constructed. The electromagnetic characteristics and the beam wave interaction of this structure are investigated. The beam current is set to be 100 mA, and the cathode voltage is tuned from 16.8 kV to 15.8 kV. The calculation results show that this tube can produce a saturated average output power over 100 W with an instantaneous bandwidth greater than 1.25 GHz in the frequency ranging from 58 GHz to 62 GHz. The corresponding gain and electronic efficiency can reach over 32 dB and 6.5%, respectively.

关键词： coupled-cavity traveling-wave tube V band re-entrant double-staggered ladder slow-wave structure