Preparation and Long Persistence Red Luminescence of M_ (0.2)Ca_(0.8)TiO_3∶Pr ~(3 ) (M=Mg~(2 ), Sr~(2 ), Ba~(2 ), Zn ~(2 )

Inthe 1990s ,newaluminatelongafterglowphos phorswerereported ,theluminescenceintensityandtheafterglowpersistencearemuchhigherthanthatofthetraditionalsulfide .Moreover ,theydonotcontainradiativeelementandhasgoodstructuralstability .Therehasbeenincreasinginterestonthenewphos phorsovertheworld .Thewideanddeepresearchonthisnewmaterialhasbeenmadeinrecentyears[1～ 3] .Nowadays ,thegreenandbluephosphorescencephos phorscanbesuccessfullypreparedwhichlastsmorethan 30and 12hrespectively[4 ] .Ithasalread…     

含Ni~(2+),Fe~(3+),Mg~(2+)的硫酸盐溶液萃取分离Cu~(2+)

采用Lix984作萃取剂,煤油作稀释剂混合而成溶液萃取的有机相,从含Ni~(2+),Fe~(3+),Mg~(2+)离子的硫酸盐溶液中萃取分离Cu~(2+).实验结果表明,在一定范围内,铜萃取率随萃取剂浓度的升高、相比的增加、萃取时间的延长、初始水相pH值的增加、萃取温度的升高以及搅拌时间的延长而增加.本实验的优化条件为萃取剂体积分数达60%,相比为O∶A=2∶1,萃取时间为16 min,萃取初始水相pH值为2.5,萃取温度在25~45℃之间,搅拌速度为240 r/min.在最佳条件下,铜萃取率高达95.55%.Fe~(3+)萃取率为8.82%,Ni~(2+)的萃取率为5.47%,Mg~(2+)的萃取率为2.36%.从而达到Cu~(2+)与其它金属离子有效分离的效果.     

Fluorescence of Sm~(2+) and Eu~(2+)→Sm~(2+) Energy Transfer in SrB_4O_7

Fluorescence spectra of Sm~(2+)and Eu~(2+)→Sm~(2+)energy transfer were studied in SrB_4O_7.There appearsonly fluorescence from ~5D_0 transition of Sm~2+ at 77 K.The vibronic lines associated with ~5D_0→~7F_0 transitionwere observed.The thermal population to upper states of ~5D_1 and 4f~5d levels from ~5D_0 gives rise to ~5D_1→~7F_J and 5d→4f radiative transitions of Sin~(2+)at higher temperature.     

LUMINESCENCE CENTERS OF Eu~(2 ) IN KCaF_3:Eu~(2 )

The nature of the emission center of Eu~(2 ) in KCaF_3:Eu~(2 ) strongly depends on the preparative condi-tions.Experimental results show that there are two different d→f transition emission bands,and the origin ofthese two emission bands,their interrelationship and the effect of doping concentration on them have been dis-cussed.A Eu~(2 )-Eu~(3 ) valency change process has been proposed.     

Crystal Structure of{[(μ_2-Cl)(C_5H_5)Sm(μ_2-Cl)]_2(μ_3-Cl)(μ_4-O)Sm(μ_2-Cl)·THF}_2~(2-)·[Li(DME)_2·Li(THF)_2·DME]~(2 )·DME

The crystal structure of title complex has been determined by the method of X-ray single crystaldiffraction.The crystal belongs to monoclinic space group C_(2/c)with the unit parameters a=2.8907(7),b=2.0431(5),c=1.5723(3)nm;β=115.67(2)°.The unit volume V is 8.36924(348)nm~3;Z=8,Dc=1,82g·cm~(-3),μ(MoK_α)=46.4cn~(-1); F(000)=4416.The final R is 0.083,Rw 0.088.The title complex con-sists of two univalent cations and one divalent anion.The anion has a cluster structure including six Sm~(3 ).Coordination numbers of all six Sm~(3 )are eight,but their surroundings are different from each other.Two ofthem are decahedral array,and the others are octahedral array f the centroid of each pentacyclodienyl ring istaken as one point.     

SrAl_2O_4∶Eu~(2+),Nd~(3+) and Dy~(3+) Long Afterglow Phosphor

Longafterglowphosphorabsorbingenergyfromsolar,lampandotherlightsourcesforashorttimestorestheenergyandexhibitsbrightandlong lastingphosphorescencewhichsuitsthevisualperceptionofthehumaneyewithminimumbrightness 0 32mcd·m- 2 andlastingtimemorethan 8h) .TheSrAl2 O4 ∶Eu2 +,Dy3+phosphorhasbeenknowntobeagreenlongafterglowphosphorwithanemissionpeakat 5 2 0nm[1～ 7] .ThepropertiesofthephosphorwerefurtherexaminedbythegroupofTangMingdaoandMatsuzawaTindetailin 1995and 1996respectively[1,2 ] .Inorde…     

Luminescence and Energy Transfer Properties of Ca_2Gd_8(SiO_4)_6O_2∶A(A=Pb~(2 ), Tm~(3 ))Phosphors

Compoundswiththeapatitestructureareverysuit ablehostlatticesforvariousluminescentions .ThemostwellknownexampleisSb3 andMn2 coactivatedcalci umhalophosphateCa5(PO4 ) 3(F ,Cl)∶Sb ,Mn ,whichhasfoundapplicationsinfluorescentlampsforalongtime[1] .Ca2 R8(SiO4 ) 6 O2 (R =Y ,Gd ,La)isakindofternaryrare earth metalsilicatewiththeoxyapatitestructure ,whichhasbeenusedashostmaterialsfortheluminescenceofvariousrareearthandmercury likeions[2～ 4 ] .Themostprominentstructuralcharacteristicisthetwos…     

(Sm2O3)0.04(Gd2O3)0.06掺杂CeO2纳米粉体的制备与表征

以Sm2O3、Gd2O3与Ce2(CO3)3·nH2O为原料,采用改进的沉淀法制备了二元稀土(Sm2O3)0.04 (Gd2O3)0.06掺杂CeO2纳米粉体.测定了pH值对0.80Ce(OH)4·0.08Sm(OH)3·0.12Gd(OH)3水溶胶体系Zeta电位的影响.pH值约为7.0时,体系的Zeta电位为0,即体系的等电点(IEP)为7.0.pH值为10.0时,Zeta电位达到最大值-18.5mV,说明此时该体系的稳定性最好.DTA/TG热分析表明,0.80Ce(OH)4·0.08Sm(OH)3·0.12Gd(OH)3粉体的热分解温度约为232℃.由粉末XRD分析可知,经750℃焙烧的二元稀土掺杂CeO2粉末为立方萤石结构,说明Sm2O3与Gd2O3已完全固溶到CeO2中,形成了CeO2基固溶体.由TEM照片可以看出,粉末具有良好的分散性,呈软团聚状态,粒径在5nm～10nm之间.经BET测试计算的平均颗粒尺寸为11nm,与TEM结果是一致的.     

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…     

Luminescent Properties of BaMgAl_(10)O_(17)∶Eu~(2+) Phosphors Coated with Y_2SiO_5

BaMgAl_(10)O_(17)∶Eu~(2+)(BAM)is the blue compo-nent of the rare earth tricolor phosphor,and it hasbeen widely applied in tricolor fluorescent lamps duetoits highluminescent efficiency.However,deteriora-tion of this phosphor[1~5]li mits the lifeti me of thelamps.The deterioration of the brightness has twoforms:thermal deterioration and deterioration in igni-tion.Thermal deterioration mainly happens inthe pro-cess of lamp production.In general,it is consideredthat this deterioration comes f…     

(ZrO2)0.96(Y2O3)0.03(Al2O3)0.01陶瓷的制备及性能研究

采用化学共沉淀法制备（ZrO2）0.96（Y2O3）0.03（Al2O3）0.01的粉末, 在不同的升温速率、不同的烧结时间和不同的烧结温度等烧结工艺下制备出（ZrO2）0.96（Y2O3）0.03（Al2O3）0.01三相体系复合陶瓷. 经研究发现, 在升温速率和降温速率均为5 ℃·min^-1 的烧结制度下, 1550 ℃烧结时, 可以得到抗弯强度达998 MPa, 抗热震次数达33次, 相对密度达96%和电性能较好的烧结体.     

Binuclear Lanthanide Complexes Containing SodiumSyntheses and Crystal Structure of (C_5Me_5)_2Nd(μ-Cl)_2Na(DME)_2 and (C_5Me_5)_2Nd(μ-OCH_3)_2Na(DME)_2

The reaction of NdCl_3 with NaC_5Me_5 generates a novel complex (C_5Me_5)_2Nd(μ-Cl)_2Na(DME)_2 (1).Then (1) reacts with 1 mol ratio Na and a little methyl-naphthalene generating another novel complex(C_5Me_5)_2Nd(μ-OCH_3)_2Na(DME)_2 (2).Complex (1) belongs to orthorhombic crystal system,space groupPbn2_1 with a=1.2635(3) nm,b=1.6127(5) nm,c=1.6543(4J nm,V=3.371(2) nm~3,D_c=1.36 gcm~(-3) andZ=4.The central metal Nd is coordinated by two C_5Me5 ring centroids and two μ-chlorine atoms forming adistorted tetrahedron.The crystal of complex (2) is monoclinic,space group C2/n with a=1.7482(5) nm,b=1.3260(4) nm,c=1.6406(7) nm,β=109.39(3)°,V=3.5874(1) nm~3,D_c=1.26 gcm~(-3) and Z=4,Twofive-membered ring centroids and two p-oxygens of OCH_3 form a distorted tetrahedron around the centralneodymium ion.     

Eu(bpy)2(NO3)3(H2O)2/Nafion修饰于金电极上的电化学发光性质研究

本文合成了铕-联吡啶的二元配合物Eu(bpy)2(NO3)3(H2O)2,用元素分析、红外及紫外光谱对配合物进行了表征.采用循环伏安法,研究了用Nafion将Eu(bpy)2(NO3)3(H2O)2修饰于金电极上的电化学发光行为.讨论了介质、pH对该体系电化学发光性质的影响,推测了Eu(bpy)2(NO3)3(H2O)2电化学发光的机理.结果表明:在没有共反应试剂存在的条件下,Eu(bpy)2(NO3)3(H2O)2在pH 8.0的硼砂缓冲溶液中可以产生较强的电化学发光,其发光体可能为Eu*(bpy)2(NO3)3(H2O)2.     

Preparation of Stable CaS∶Eu~(2+), Tm~(3+) Phosphor

Alkalineearthsulfides (AES)havebeenfoundtobeexcellentandversatilephosphor ,andrareearthsasactivatorshavebeenintensivelyinvestigated[1～ 7] .Theyholdpromiseforapplicationsinphoto ,electro ,cathoderay ,fieldemissiondisplaysandluminescencepaints[8,9] .However ,alkalineearthsulfidesasaphos phorhosthavebeenfoundtobelimitedinapplica tion ,duemainlytoitssensitivetomoistureandotheratmosphericcomponents .Theirchemicalstabilityagainstatmosphericcarbondioxideandmoisturecouldbeenhancedthroughthegoodcryst…     

挤压筒强度优化设计(2)

9q刀包申雨o。（》①。门〕_垫_9（卜卜 卜,）………门3）—-””————一’”’”RR“”-“ala。,、hib3中公才a（》一子 兴及V（门一子十六由l比.函数中侣）和下侣）解为:_。_、。。_。^__….d（入）日1。。＊‘犬一阶导数、二阶导数:Q（Z）一>一兰 兰 3％三—……·（74）J“”’————”一”’”“——“—”一卜’（》R一Pal.3a。、,。。。丫（U—一（兴十尖）……·’·（63）_,_、1,’（Uh’（U一0’丛丛二竺,”’”””入‘入’”e〔Z）一工二二二二一一干7厂卜大二二二二二一、一·lh’（人）卜2al.12a3、I。。\_。’。…     

基于Cu~+-In~(3+)-Se~(2-)-NH_3-L~(2-)-Cl~--H_2O体系的常温全液相法制备CuInSe_2粉体

采用同时平衡和质量守恒原理对全液相常温常压法制备CuInSe2(CIS)粉体过程中Cu+-In3+-Se2--NH3-L2--Cl--H2O体系的热力学平衡进行分析,并绘制一系列的浓度对数lgc-p H值曲线.依据平衡图,发现溶液中[NH3]T的变化主要影响溶液中[Cu+]T在体系中的浓度变化,[L2-]T的变化主要影响的是体系中[In3+]T的浓度变化,而[Cl-]T的变化对[Cu+]T和[In3+]T的浓度变化均有影响,并可发现在pH 7.0~8.5时沉淀率最高.依据Cu+-In3+-Se2--NH3-L2--Cl--H2O体系的同时平衡和质量守恒原理,采用全液相常温常压法,在pH 7.0~8.5条件下制备出粒径在20~50 nm且基本符合标准化学计量比的CIS纳米粉体.     

从Fe~(2 )-NH_3-(NH_4)_2SO_4-O_2体系中沉淀砷

多年来 ,从湿法冶金工艺溶液中除砷一直采用砷酸铁沉淀法或氢氧化铁共沉淀法。在许多冰铜和硫化物精矿中 ,砷以 As3 存在 ,沉淀前需氧化成 As5 ,而且溶液中必须含足够量的铁。但在 Fe2 -NH3-( NH4) 2 SO4-O2 体系中沉淀砷时 ,铁不再以 Fe3O4形式沉淀 ,而是形成含 x H2 O的水合砷酸铁或多种通式为 Fe ASO4· x Fe( OH) 3的碱性砷酸铁。R.P.Das和 S.Anand研究了在 Fe2 -NH3-( NH4) 2 SO4-O2 体系中沉淀砷时 ,初始砷质量浓度、温度和氧分压的影响。试验在装有可控温度和速度的 2 L 不锈钢加压釜中进行。所有试验的转速为 5 0 …     

Thermal Decomposition Mechanism and Non Isothermal Kinetics of Complex of [La_2(P-MBA)_6(PHEN)_2]2H_2O

Ｏｗｉｎｇｔｏｔｈｅｖａｒｉａｔｉｏｎｏｆｃｏｏｒｄｉｎａｔｅｄｍｏｄｅｓｆｏｒｃａｒｂｏｘｙｌａｔｅａｎｉｏｎｓ ,ｍａｎｙｄｉｆｆｅｒｅｎｔｔｙｐｅｓｏｆｃｒｙｓｔａｌｓｔｒｕｃｔｕｒｅｓｆｏｒｔｈｅｒａｒｅｅａｒｔｈｃｏｍｐｌｅｘｅｓｗｉｔｈａｒｏｍａｔｉｃａｃｉｄａｎｄｎｉｔｒｏｇｅｎ ｃｏｎｔａｉｎｉｎｇｌｉｇａｎｄｓｗｅｒｅｏｂｔａｉｎｅｄ[1～ 4 ] .Ｔｈｅｉｒｔｈｅｒｍａｌｄｅｃｏｍｐｏｓｉｔｉｏｎｂｅｈａｖｉｏｒｈａｄｂｅｅｎｒｅ ｐｏｒｔｅｄｉｎｐｒｅｖｉｏｕｓｐａｐｅｒｓ[5～ 8] .…     

Synthesis and Crystal Structure of Lutetium Complex withTriethylenetetraaminehexaacetic Acid (H_6ttha):{[Lu_2 (ttha) (H_2O)_6Lu_2 (ttha) (H_2O)_4]·21H_2O}_n

Paramagneticmetali0ncomplexeshavemanyapplicati0nsinbiomedicine,especiallyasbioconjugatesf0rmonoclonalantib0dyradioiso-topelabelingandasmagneticresonanceimaging(MRI)agents["'].Polyaminepolycarboxylicacidsandtheirderivativesareveryimportantchelatingagentsformetalions,anddiethylene-triaminepentaaceticacid(H,dtpa)complexwithgadoliniumhasbeenusedasMRlagentintheNMRdiagnosisoft....,[3'4j.HavingsimilarcoordinationabilitywithH5dtpatowardlan-thanideions,triethylenetetraaminehexaaceticacid(H,ttha)can…     

La2(SO4)3/SiO2催化合成增塑剂

以La2(SO4)3/SiO2为催化剂,顺丁烯二酸酐和丁醇为原料,合成内增塑剂顺丁烯二酸二丁酯,探讨了催化剂用量,酐醇物质的量比以及反应时间等对收率的影响.结果表明,La2(SO4)3/SiO2对顺丁烯二酸二丁酯的合成具有良好的催化活性,在适宜的条件下其收率可达99%.当把此催化剂用于合成柠檬酸三丁酯、邻苯二甲酸二辛酯、丁二酸二丁酯时,同样具有良好的催化活性.