Forming regularity and relation between composition and property of B_2O_3-BaO-ZnO glass

1INTRODUCTION Colorplasmadisplaypanel(PDP)isakindofeligibleapparatusforlargearea,hang on wallhighdefinitiontelevisions,computermonitorsandvari ousdisplaypanelsforcivilianandmilitaryapplica tion[13].Comparedwithotherflatdisplaypanels,themarketperspectiveforPDPisrapidlygrowingbecauseoftheiradvantagessuchasthinthickness,lowdensity,largeareaandlargevisualangle[4,5].TheglasssubstratesandthedisplayelectrodesinPDParethemainpartsandplayaveryimportantroleinhighperformancePDP[6].Inordertopro t…     

Bi_2O_3-GeO_2(B_2O_3)玻璃的结构研究

本文测定了铋锗酸盐、铋硼酸盐玻璃的IR光谱和EXAFS谱,分析了Bi~(3+)对B-O、Ge-O网络结构的影响,讨论了Bi~(3+)在氧化物玻璃中的结构形态。结果表明:Bi_2O_3能够给锗酸盐玻璃提供非桥氧,使[GeO_4]四面体构成的结构网络解聚;Bi_2O_3能够提供游离氧给硼酸盐玻璃,使[BO_3]三角体转变成[BO_4]四面体。晶体中不规则的[BiO_6]八面体在玻璃中产生了更为严重的畸变,使极化率很大的Bi~(3+)离子在氧化物玻璃中可能以低配位的[BiO_3]基团形式存在。     

Influence of ZrO_2 on sintering and crystallization of CaO-Al_2O_3-SiO_2 glass-ceramics

1INTRODUCTION Nowadays,glassresearchersandarchitecture designersbecomeinterestedinthesinteringglass ceramics,anewlyappearingmaterialforarchitec turaldecoration[13].Comparedwithnaturalstone materials,sinteringglass ceramicsdecoratedmate rialshavethefollowingadvantages:densestruc tureandhighstrength.Itsbasicglasscomponents belongtoCaO Al2O3SiO2system.Becausenonu cleationagentisrequired,thissystemisattributed tothesuperficialcrystallizationmechanismofglass[4].Theproductionprocessofsinteri…     

Microstructures and properties of WC-20Co-1Y_2O_3 cemented carbide by hot-press and liquid phase sintering

1　INTRODUCTIONInRef .[1],averyinterestingandinexplicablefindingwasreportedthataspecialwhisker likeWCgrainstructure ,mostintherangeof 10 0 2 0 0nmindiameterand 1 2mminlength ,wasformedinWC 2 0Co 1Y2 O3cementedcarbidepreparedbyhot pressbelowtheeutectictemperature .ItwasmentionedinthepaperthatWCpowderwithFisherSubsiereSizer(FSSS)of 1μm ,ultrafineCopowder ,andY2 O3powderof 1μmwereusedastherawmaterialsofWC 8Cocementedcarbide .However ,whetherthesamerawmaterialswereusedinWC 2 0Co …     

STRUCTURE STUDY OF GLASSES IN BINARY Bi_2O_3-GeO_2 AND Bi_2O_3-B_2O_3 SYSTEMS

IR and EXAFS spectra of two binaryBi_2O_3-GeO_2 and Bi_2O_3-B_2O_3 glasses aremeasured,the effect of Bi~(3+) on B-O,Ge-Onetwork structure is analysed,and thelocal structure of Bi~(3+) in oxide glasseshas been discussed.The results show:Bi_2O_3 can introduce some non-bridgingoxygens to Bismuth Germanate glasses todepolymerize the Ge-O tetrahedronnetwork and give part of its oxygens toBismuth Borate glasses to form four-coordinated sites.Asymmetric [BiO_6]octahedra are distorted in oxide glasses.The highly polarizable Bi~(3+) ions partici-pate in the structure of oxide glasses byforming [BiO_3] groups.     

Luminescent properties of BaO-La_2O_3-B_2O_3 glasses with dopant

1　INTRODUCTIONResearcheshaveconfirmedthatonlyblueandredcomponentsofsunlightcanbeefficientlyabsorbedbychlorophyllmolecules[14 ] .Thereforealargeportionofsolarenergy ,particularlytheultravioletandgreencomponentsofsunlightcannotbeuseddirectlybygreenplants .A possiblewaytoincreasetheproduc tivityofgreenplantsistoconvertultravioletorgreencomponentofsunlightintoblueorredlight ,whichisbecomingmoreandmoreimportantwiththeincreaseofworld population .Thereisevidencethatthegreenhousemadeoftheplastic…     

Antibiotic properties of Al_2O_3 doping silver

1INTRODUCTION Sterilizationisanimportantprocedureto maintainsanitaryenvironment,andinorganicanti bacterialmaterials,especiallydopingsilverion,havemanyadvancedfunctionsandfeatures,inclu dinghighstability,strongantibacterialfunction, highsafetyandheat resistantproperty[1].Atpres ent,thecarriersofinorganicantibacterialmaterials containingsilverthathavebeendevelopedaregen erallyzeolite,calciumphosphate,siallite,phos phoricacidzirconium,activatedcarbonandsilicageletc[24].Butthecarriersmenti…     

TiO_2对Bi_2O_3-SiO_2-ZnO-B_2O_3玻璃性能影响

TiO2掺杂的铋锌硼玻璃作为封接玻璃和特种光学玻璃材料,其光学特性和化学稳定性研究是至关重要的。主要研究了掺加2%、4%、6%和8%TiO2的Bi2O3-SiO2-ZnO-B2O3体系玻璃的光学和化学稳定性,研究结果表明:玻璃表面没有条纹和缺陷,从可见光透过率可知,玻璃为半透明,透过率在20%~50%之间。玻璃的耐水性能受玻璃中离子含量的影响较大,Ti离子的含量越高,结构越稳定,耐水性能越好;玻璃的耐酸性能与结构中阳离子的极化能力有关,极化能力越大,耐酸性能越好,而且玻璃的侵蚀是渐缓的;玻璃在碱性介质中的侵蚀机理是铋锌硼长链末节的金属离子被水化,导致Bi-O-Bi断键,耐碱性能变差,加入TiO2后,改善其耐碱性能。     

Bi_2O_3-B_2O_3-RE_2O_3(RE=Ce,Tb)玻璃的光学带隙

采用熔融法制备了Bi2O3-B2O3-RE2O3(RE=Ce,Tb)玻璃,根据Urbach公式和Tauc方程分别计算了含不同种类稀土玻璃的Urbach能及光学带隙,并探究了Urbach能与光学带隙的关系.结果表明:增加稀土离子,玻璃中非桥氧键增多,玻璃的结构疏松,电子跃迁所需的能量降低,Urbach能降低;随着极化率增加,玻璃的键强降低,吸收边增加,光学带隙减小,且光学带隙随着Urbach能的减小线性降低.     

Preparation and properties of a new scintillating glass

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｈｉｇｈ ｅｎｅｒｇｙｐａｒｔｉｃｌｅｐｈｙｓｉｃｓｅｘｐｅｒｉｍｅｎｔｓｎｅｅｄｄｅｔｅｃｔｏｒｓ ,ｗｈｉｃｈｃａｎｂｅｕｓｅｄｉｎｈｉｇｈｒａｄｉａｔｉｏｎｅｎｖｉｒｏｎｍｅｎｔ.Ｔｈｅｓｅｄｅｔｅｃｔｏｒｓｒｅｑｕｉｒ     

Bi_2O_3-P_2O_5二元系统玻璃性能

采用高温熔融的方法制备xBi_2O_3-(100-x)P_2O_5二元系统玻璃,研究了Bi_2O_3含量变化对该体系玻璃的结构、热膨胀系数、密度和化学稳定性等的影响。在二元系统中随着Bi_2O_3含量的增加,熔融温度不断升高。当Bi_2O_3摩尔分数达到30%,在1 200℃下熔制且保温2h的玻璃液均化程度高、成玻性能良好,化学稳定性达到最好。随着Bi_2O_3含量的增加,热膨胀系数呈先减小后增大的趋势,在Bi_2O_3摩尔分数为25%出现最小值。     

Microstructures and properties of WC-2OCo-1Y2O3 cemented carbide by hot-press and liquid phase sintering

Ultrafine tungsten carbide and fine cobalt as well as nano yttrium oxide powders were used as the raw materials. The effects of hot-press below the eutectic temperature and conventional liquid phase sintering on the structures and properties of WC-20Co-1Y2O3 cemented carbide were studied. It is shown that hot-pressed alloy has the character of isotropic properties and microstructure with homogeneous and ultrafine WC grains. However, the ultrafine and fully-densified structure is developed at the cost of the presence of large amount of cobalt-lake (uneven-ly distributed binder phase), and thus lower strength. Yttrium oxide in the alloy cannot play the role of grain growth inhibitor fully when cemented carbide with high content of cobalt and ultrafine raw materials is sintered at high liquid phase sintering temperature. Peculiar platelet-enhanced bi-model structure is formed in WC-20Co-1Y2 O3 cemented carbide by conventional liquid phase sintering, which points out that yttrium oxide in the alloy facilitates the formation of plate-like WC grain.     

B_2O_3-Li_2O-LiCl-Al_2O_3系统非晶态快离子导体

本文研究了B_2O_3—Li_2O—LiCl—Al_2O_3系统非晶态快离子导体的导电性。用红外光谱、X射线荧光分析术研究了该系统玻璃的结构,以及LiCl、Al_2O_3对本系统玻璃中Li~+离子导电性能的影响。Li_2O的加入,使硼氧三角体[BO_3]转变为硼氧四面体[BO_4],当Li_2O含量超过30mol％时,玻璃中主要是含[BO_4]较多的二硼酸盐基团。LiCl的加入,对玻璃结构没有明显的影响,其处于被网络骨架解离的状态。但随LiCl含量的增加,离子电导率迅速上升。引入Al_2O_3,使玻璃能在室温冷却条件下形成,且都使电导率下降,导电活化能升高。但高温下电导率下降并不明显。实验测得室温下离子电导率σ=6.2×10~(-6)Ω~(-1)cm~(-1),300℃时σ=6.8×10~(-3)Ω~(-1)cm~(-1),计算的导电活化能值为0.6～1.0eV。     

Effect of nucleating agents on microstructure and mechanical properties of SiO_2-Al_2O_3-ZrO_2 glass-ceramics

1INTRODUCTION Glass ceramicsarepolycrystallinematerials composedofatleastonecrystallinephaseanda vitreousmatrixphase,whichisproducedbythe controlledcrystallization.Wide rangingproperties ofglass ceramicscanbemodifiedinapredictable waybycontrollingthechemicalcompositionsand heattreatmentschedule[16].Al2O3SiO2ZrO2sys temisseldomreportedduetothehighmelting temperature.ZrO2,TiO2andP2O5arecommon nucleatingagents.Inglass ceramics,ZrO2isanef fectivenucleatingagentduetothecharacteristics ofh…     

Dielectric Properties of B_2O_3 Doped MgTiO_3-CaTiO_3 System Ceramics

1　IntroductionMgTiO3 basedceramicsarewellknownasmicrowavedielectricwithhighQvalueandlowτfvalue .Since1990s ,FerreiraetalReportedthemicrowavedielectricpropertiesofMgTiO3 CaTiO3ceramicsdopedwithLa2 O3,Cr2 O3[1 3] .Mostoftheresearcheswereconcernedwithimpro…     

Bi_2O_3和Fe_2O_3掺杂对BaTiO_3陶瓷显微结构的影响

利用扫描电子显微镜（ＳＥＭ）、透射电子显微镜（ＴＥＭ）和Ｘ射线能量色散谱（ＥＤＡＸ）等结构分析 技术,研究了施主（Ｂｉ３＋）和受主（Ｆｅ３＋）掺杂对ＢａＴｉＯ３陶瓷显微结构的影响。研究结果表明;施主掺杂抑制晶 粒生长,受主掺杂则促进晶粒生长;受主（Ｆｅ３＋）掺杂导致部分晶粒中出现壳－芯结构和包晶结构特征,ＦＤＡＸ 微区分析证实,壳－芯结构和包晶结构的形成都与Ｆｅ３＋的偏析有关;在 Ｂｉ掺杂ＢａＴｉＯ３陶瓷晶粒中发现子离 子化合物材料中比较罕见的位错网。     

Bi_2O_3-B_2O_3体系玻璃的形成结构与性能研究

采用熔融急冷法制备了Bi2O3摩尔分数为25%~60%的Bi2O3-B2O3体系玻璃,对玻璃的形成能力、基本结构和性能进行了研究。X射线粉末衍射分析结果表明该体系的成玻性能较好,成玻范围较宽;FT-IR分析结果表明玻璃中含有[BO3]和[BO4]结构基团。利用差热分析(DTA)确定该体系玻璃的特征温度,以及特征温度随组成的变化;根据Brewster定律测量并计算了玻璃的折射率;根据阿基米德定律测试玻璃的密度和显微硬度,发现玻璃的显微硬度随着体系中Bi2O3含量的增加而减小,而密度随着体系中Bi2O3含量的增加而增加。     

PbO—ZnO—B_2O_3低熔玻璃析晶的研究

本文研究了 PbO-ZnO-B_2O_3低熔玻璃的析晶。利用 Kissinger 修正方程计算了样品的析晶活化能,同时根据测出的表面析晶层厚度随时间的变化,求出析晶速率。析出的晶相用 x-射线衍射进行了分析鉴定,晶相的形貌用扫描电镜进行了观察。对热处理前后的样品进行了喇曼光谱和红外光谱的测定,并对结构可能产生的变化进行了探讨。     

La , Li＋ Precipitation processes and luminescence properties of ZnO： 3＋ nanoparticles

ZnO:La3+ ,Li+ nanoparticles were successfully prepared by co-precipitation, citric acid-assisted co-precipitation, co-precipitation combined solid-state reaction and thermal decomposition method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and luminescence spectrophotometry were employed to characterize the crystal phases, particle sizes and luminescence properties of the as-prepared nanopowders. The results indicate that all the prepared samples crystallize in a hexagonal wurtzite structure. The ZnO:La 3+ ,Li+ prepared by citric acid-assisted co-precipitation method has a particle size of about 80 nm, which is the smallest among all the samples. Fluorescence (FL) spectra of all samples exhibit three typical emissions: a violet one centered at around 400 nm, blue around 450 nm and 466 nm, and weak green near 520 nm. But the samples prepared by co-precipitation method show a strong and wide green light emission located at about 500 nm. The ZnO:La 3+ ,Li+ nanoparticles synthesized by the co-precipitation method demonstrate relatively the strongest emission intensity.