Synthesis of YAG∶Ce~(3+) Phosphor by Polyacrylamide Gel Method and Promoting Action of α-Al_2O_3 Seed Crystal on Phase Formation

Cerium activatedyttriumaluminumgarnet Y3Al5O12(YAG∶Ce3+)isknownasanefficientphos phor,whichhasstrongyellowluminescencewhenex citedbybluephotons.Therefore,YAG∶Ceisideally suitedforluminescenceconversionofbluelightemit tingdiodes[1,2],andusedintheassemblingofwhite lightemittingdiode(wLED),sinceblueandyellow arecomplementarycolors.Suchdiodesarenowcom merciallyavailable[2].HighluminancewhiteLEDhas beenarousedattentionaroundworldduetoitslighting withnohydrargyrum,highefficiencyandlonglife.…     

Characterization of Y_2O_2S∶Eu ~(3+), Mg~(2+), Ti~(4+) Long-Lasting Phosphor Synthesized by Flux Method

Long lastingphosphorescence(LLP)isaproper tyofphosphorswithlongdecaytime,rangingfroma fewminutestotensofhours[1].Inrecentyears,LLP materialshavebeenwidelyusedinmanyfieldssuch asroadsigns,emergencylighting,graphicarts,inte riordecoration,automobileinstrument,andoptical datastorage[2～4].Buttodate,theprogressonred phosphorescenceisveryslow.TheredLLPmaterialbasedonsulfide(CaS∶Eu3+)hasnearly3hafterglow.However,itisex tremelysensitivetomoistureandthuschemicallyun stable[5].CaTiO3∶Pr3+,BaT…     

Improvement on Hot Workability of

［1］Kim Y W. Intermetallics Alloys Based on Gamma Titanium Aluminide [J]. JOM,1989,41(7):24-30. ［2］Kim Y W, Dimiduk D M. Progress in the Understanding of Gamma Titanium Aluminides [J]. JOM,1991,43(8):40-47. ［3］Kim Y W. Ordered Intermetallic Alloys, Part III: Gamma Titanium Aluminides [J]. JOM,1994,46(7):30-39. ［4］Kim Y W. Wrought TiAl Alloy Design [J]. Trans Nonfe-rrous Met Soc China,1999,9(Supp l.1):298-308. ［5］Zhong Zenyong, Zhang Ji, Li Shiqiong, et al. Microstruc-ture Modifications of Wrought and Cast TiAl Alloys [J].Trans Nonferrous Met Soc China,1999,9(Supp l.1):188-196. ［6］Zhang Ji, Zhang Zhihong, Su Xi, et al. Microstructure Prep-aration and Hot-Deformation of Ti-46.2Al-2.0V-1.0Cr-0.5Ni Alloy [J]. Intermetallics,2000,8:321-326. ［7］Hodgson J M, Srinivasan R, Lipsitt H A. The Workability of Some Near Gamma Titanium Aluminide Base Alloys [A]. S Ankem, J A Hall eds. Microstructure/Property Relationships of Titanium Alloys [C], Warrendale: TMS,1994.255-261. ［8］Singh J P, Tuval E, Weiss I, et al. Isothermal Deformation of Gamma Titanium Aluminide [A]. Kim Y W, Wagner R,Yamaguchi M eds. Gamma Titanium Aluminides [C]. War-rendale: TMS,1995.547-554. ［9］Pu Zhongjie. The Study on the Behaviors of Deformation,Fracture and Ductility Approach of TiAl Compound [D].Beijing: Central Iron & Steel Research Institute,1990 (in Chinese). ［10］Su Xi, Li Shiqiong, Zou Dunxu, et al. Study on Hot Deformation Properties of Ti-47Al-2Cr-2Nb-1Mo Alloy [J]. Acta Metallurgica Sinica,1999(Supp l.2):428-430. ［11］Shi Jiandong. The Study on the Influence of Microstructures on Mechanical Properties, and Toughening Approach of TiAl Alloy [D]. Beijing: Central Iron & Steel Research Institute,1994 (in Chinese). ［12］Su Xi, Zhang Ji, Zhang Zhihong, et al. Study on Hot Deformability of Gamma Titanium Aluminide Alloys [J]. Acta Metallurgica Sinica, 1999(Supp l.1):280-283.     

Study on Scrapping Mechanism of Forging for Boiler

［1］Li Daizhong. Non-Metallic Conclusion in the Steel [M].Beijing: Science Press,1983 (in Chinese). ［2］Chen Yongyi. Steel Metallurgy [M]. Beijing: Metallurgical Press,1980 (in Chinese). ［3］Kang Dadao. Material and Heat Treatment of Large Forgings [M]. Beijing: Longmen Publishing House,1998(in Chinese). ［4］Chen Dehe. The Steel Defect [M]. Beijing: China Machine Press,1977 (in Chinese). ［5］Wan Xiaojing. The Metallic Hydrogen Brittleness [M].Beijing: Science Press,1981 (in Chinese). ［6］Kang Dadao. Heat Treatment of Large Forgings [M]. Beijing:China Machine Press,1977 (in Chinese). ［7］Large Forging & Casting Trade Association. The Defect Analy-sis Atlas of Large Forgings and Castings [M]. Beijing: China Machine Press,1990 (in Chinese). ［8］Metallic Mechanical Property Writing Group. Metallic Mechan-ical Property [M]. Beijing: China Machine Press,1982 (inChinese).     

Luminescence Properties of Green-Emitting Phosphor (Ba_(1-x),Sr_x_2SiO_4∶Eu~(2+) for White LEDS

Whitelightemittingdiode(LED)iswell known assolid statedevicesthatconsistsofablueornear UVLEDchipandblue yelloworblue green red phosphors[1].AwhiteLEDthatcombinesablueLED andaYAGphosphorwasmadeavailableonthemar ketin1996[2].However,furtherstudyindicatedthat whiteLEDbypre coatingblue green redphosphors ontoalongUVLEDchipismuchmoreopticallysta blethantheconventional“blueyellow”whiteLED.Becauseitispossibletoimprovetheluminousefficacy ofwhiteLEDSexcitedbynear UVLEDSinthenear UVtob…     

中医药治疗糖尿病视网膜病变进展

糖尿病视网膜病变(diabetic retinopathy,DR)是糖尿病严重并发症之一.美国对2005-2008年40岁以上的糖尿病患者进行调查发现,DR患病率为28.5%[1].几乎所有病程在20年以上的糖尿病患者都存在不同程度的视网膜病变[2].DR导致的失明占所有失明人数的8.9%[3].     

婴幼儿抗生素相关性腹泻的微生态疗法及专科护理

抗生素相关性腹泻(Antibiotic-associated diarrhea.AAD)是指因感染性疾病,在接受抗生素治疗后2h~2月内,发生的不能解释的腹泻[1].可以说抗生素使肠道菌群失调是AAD发生和发展的基础[2].国内外已有不少文献报道益生菌制剂可用来预防和治疗AAD[3].因此,近年来,调节机体正常菌群平衡的微生态制剂开始受到广泛的关注和重视,AAD的治疗越来越多地采用微生态疗法并配合专科护理.现就微生态疗法配合专科护理在AAD临床治疗中的应用作一总结.     

Preparation and Characterization of Porous Yttrium Oxide Powders with High Specific Surface Area

Y2O3isoftenusedinthemanufactureofphos phorsandceramics[1～3].However,itisalsousedas selectivecatalysts[1,4,5],suchasforthedehydrationof2alkanols,thedimerizationofmethane,1butene isomerization,hydrogenationof1,3butadieneandac etonealdoladdition,andsupport[6,7]formetalsthat catalyzetheformationofmethanolfromCO2andH2.It iswidelyacceptedthatthecatalysispropertiesofox idesdependstronglyontheirphysicalcharacteristics,especiallyontheirspecificsurfaceareaandporous structure.Agreatdealofattentionhasb…     

Preparation of Nano Y_2O_2S∶Eu Phosphor by Ethanol Assisted Combustion Synthesis Method

Rareearthoxysulfidematerialsexhibithighlumi nescentefficiencyaswellasexcellentchemicalstabili ty.Thesematerialsarewidelyusedasluminescent hostmaterialsofseveralcommerciallyavailablephos phorssuchasredemittingphosphorsforcolortelevi sionpicturetube,X rayphosphors[1],andlongafter glowpigments[2].Thereexistseveralmethodsinpre paringrareearthoxysulfides:(1)Traditionalsulfide fusionmethod,i.e.sulfurationofrareearthoxidein theflux(Na2CO3K2CO3K3PO4)athighte mperature[3,4],whichiswidelyemployedona…     

Evaluation of Component Activity in Mol ten MnO-SiO2-Al2O3-CaO System with Model SELF-SReM4

ItwasemphasizedthatSELF-SReM4isapplicabletoevaluatethethermodynamicpropertyofahomogeneousregionofrandomquaternarysystems.Asamatteroffact,ananalysisofSi-basedalloywascarriedoutbymeansofSELF-SReM3[1].ThepurposeofthispaperistoevaluateactivityofthecomponentsintheliquidregionofthemoltenslagMnO-SiO2-Al2O3-CaOwithmodelSELF-SReM4.　　Certainly,SELF-SReM4canbeattributedtothecategoryofthermodynamicparametermodel.Itneitherconcernswiththebondstructureoftheslagnorintendstolinkupitsmacroscopi…     

镁的合金化与合金相图

论文分析了镁基合金二元和多元相图的研究现状；指出了镁合金在合金化中存在的问题。在此基础上探讨了在镁合金的设计与研究过程中如何进行相图的研究。指出由6－10个元素组成镁合金集团进行合金相图的实验测定和热力学计算的方案是可行的。     

Experimental Study and Thermodynamic Optimization of the FeO-V_2O_3 System

Optimization of the phase diagram of FeO-V2O3 system is a part of an on-going research project to develop a self-consistent multi-component thermodynamic database for vanadium slag from hot metal.Due to the lack of experimental data for optimization,a novel experimental investigation has been carried out by thermal analysis(DSC)with a series of slags on different V2O3 contents(i.e.3mass%-12mass%).All available thermodynamic and phase diagram data for the binary systems have been simultaneously optimized with CALPHAD(Calculation of Phase Diagrams)methods to give one set of model equations for the Gibbs free energy of the liquid slag as functions of composition and temperature.The modified quasi-chemical model was used to describe the binary slag system.It was demonstrated that the calculated phase diagram with the optimized parameters was in good agreement with the experimental data.     

Phase diagram of Er-Sn-Te system for diluted magnetic semiconductor developments

Phase diagrams of the RE (rare earth)-IV-VI systems are very important for the design of rare earth doped diluted magnetic semiconductors (DMSs), but related information is very limited. In this work, ...     

Experimental Study and Thermodynamic Optimization of the FeO-V203 System

Optimization of the phase diagram of FeO-V20a system is a part of an on-going research project to develop a self-consistent multi-component thermodynamic database for vanadium slag from hot metal. Due to the lack o{ ex- perimental data for optimization, a novel experimental investigation has been carried out by thermal analysis （DSC） with a series of slags on different V2 03 contents （i. e. 3mass%- 12mass%）. All available thermodynamic and phase diagram data for the binary systems have been simultaneously optimized with CALPHAD （Calculation of Phase Dia- grams） methods to give one set of model equations for the Gibbs free energy of the liquid slag as functions of compo- sition and temperature. The modified quasi-chemical model was used to describe the binary slag system. It was dem- onstrated that the calculated phase diagram with the optimized parameters was in good agreement with the experi- mental data.     

Phase Diagram of the Ni ― Os System

Metallography, DTA, x-ray, and electron-probe microanalysis methods have been applied to alloys with four compositions in the cast and annealed states. A phase diagram has been constructed for the entire concentration range on the basis of these data together with published ones. The diagram is of peritectic type, and the peritectic temperature is 1500°C. The mutual solubilities of the components at that temperature are 13.3 at.% osmium in nickel and 13 at. % nickel in osmium. The solubility of osmium in nickel falls to 9.2 at. % when the temperature is reduced to 1200°C.     

Alloy Structure and Equilibrium Phase Diagram for the Sc–Ru–Rh System. Part 7. Polythermal Sections in the Sc–Ru–Rh System

DTA, XRD, metallography, and electron-probe microanalysis have been applied to study phase compositions of cast and annealed alloys (annealing at subsolidus temperatures of 1400°C (composition range 0-50 at.% Sc) and 930°C (composition range 50-100 at.% Sc)) and construct polythermal sections for the Sc Ru Rh ternary system on the isoconcentrates 75 at.% Sc, 65 at.% Rh, and beam Ru:Rh = 1:1, as well as isoconcentrates for 5.0 ± 0.3 at.% Ru and 5 at.% Rh in the region of 50-100 at.% Sc. The sections reveal characteristic features of the phase diagram structure for this ternary system, in particular temperature ranges for crystallization and the types of phase transformation within them.     

作为材料设计基础的相图研究

介绍了现代材料设计与相图研究之间的关系，强调了计算相图的出现使相图研究成为材料的设计的一部分，相图计算程序系统的另一重要功能是评估和优化热力学参数，以双相纳米材料、宽滞后形状记忆合金、钕铁硼永磁合金、钛铝金属间化合物和低温用钢的研究开发为例，说明了相图研究在材料设计上的重要作用。     

Reaction mechanism of phosphorus with multi phase fluxes during hot metal dephosphorization

The formation of solid solution combined with tricalcium phosphate and dicalcium silicate could promote a considerable removal of phosphorus from liquid slag to solid during hot metal dephosphorization,and thus the dephosphorization by using multi phase fluxes could significantly decrease the consumption of lime. However,the reaction mechanism of multi phase fluxes has not been understood clearly.In the present study,the phase diagram for the CaO-SiO₂-FeO-P₂O₅ system has been measured with certain oxygen partial pressure at hot metal pretreatment temperature.Comparing with the CaO-SiO₂-FeO system,shrinkage of liquid phase area at higher FeO contents was observed at 1 673 K with oxygen partial pressure of 9.2×10^-11 atm.     

SrO—SrCl2渣系热力学性质的测定与计算

采用Ｍｏ│Ｍｏ＋ＭｏＯ２│ＺｒＯ２（ＭｇＯ）│Ｆｅ＋（ＦｅｘＯ）＋Ａｇ│Ｆｅ固体电池测定ＳｒＯ－ＳｒＣｌ２渣系中ＦｅｘＯ的活度，进而做出该渣系在１６２３Ｋ的等温相图，计算出中ＳｒＯ的活度，探讨了温度对渣中ＦｒｘＯ活度的影响规律。