Growth and Spectral Properties of Crystal Er~(3 )∶Y_(0.5)Gd_(0.5)VO_4

Er∶YVO4andEr∶GdVO4lasercrystalshavebeen widelystudiedandusedinlaser diodepumpedsolid statelasersfortheirgoodlaserproperties[1～4].Howev er,thethermalconductivityofEr∶YVO4crystalislow andthecrystaliseasytodecompose.ThoughEr∶GdVO4lasercrystalhasanexcell     

Preparation and Luminescence Properties of the New Long Phosphorescent Phosphors Ba_(1-x)Ca_xAl_2O_4∶Eu ~(2 ), Dy~(3 )

Inrecentyears ,SrAl2 O4 ∶Eu2 ,Dy3 ,CaAl2 O4 ∶Eu2 ,Nd3 [1～ 8] andBaAl2 O4 ∶Eu2 ,Dy3 [9]havebeenconsideredasusefulblueandgreenphos phorsbytheirlongdurationphosphorescence .Howev er ,toourknowledge ,thephosphorBa1-xCaxAl2 O4 ∶Eu2 ,Dy3 hasnotbeeninvestigated .TheluminescenceofEu2 isverystronglydepen dentonthehostlattice ,whichcanoccurfromtheul traviolettotheredregionoftheelectromagneticspec trum .Itiswellknownthatthepersistentluminescenceisduetothetrappingofenergyinthed…     

Crystal Growth and Laser Characteristics of Nd~(3+)∶KGd(WO_4)_2

The solid-state diode-pumped laser was widelyusedin many fields.With the development of crystalgrowth,many good working materials were discov-ered,such as:Nd3+∶YAG,YVO4[1],YLF[2,3],andNd3+∶KY(WO4)2(Nd∶KYW),Yb3+∶KY(WO4)2(Yb∶KYW),Nd3+∶KGd(WO4)2(Nd∶KGW)in recent10years.Compared with Nd∶YAG,Nd∶KGWhas manyoutstanding properties:the emission cross section isbig at the output wavelength of1064and1351nm,concentrate quenching of high Nd3+(at a maxi mumof10%)(atomfraction)is v…     

磨球的湿式磨损分析及对策

通过对磨球的湿式磨损分析 ,认为添加抗腐蚀剂白灰及按 1 0 0∶ 80∶ 60 =30∶ 4 0∶ 30配比补加钢球 ,使钢球单耗由 1 .0 4 kg/ t降到 0 .90 kg/ t,同时提高磨矿细度和磨矿效率 ,达到降低生产成本的目的     

低品位碳酸锰矿富集技术研究

研究了低品位碳酸锰块矿及锰粉矿焙烧工艺控制条件,确定最佳条件为:焙烧温度900～1 000℃时,块矿烧损率33. 7%,块矿中Mn元素含量26. 21%,Fe元素含量4. 32%。粉矿∶煤粉∶粘接剂∶水=12∶4∶1∶3的球团矿配比,在1 000℃的焙烧温度下,焙烧后球团矿中Mn元素含量为30. 61%,Fe元素含量为3. 77%,Mn富集量最大。     

Investigations on Valence-Change Behaviors of Europium Ions in Eu-Doped Aluminate and Silicate Phosphors

Compounds of Sr3Al2O6∶Eu, Sr4Al14O25∶Eu, and BaZnSiO4∶Eu were synthesized by high-temperature solid state reactions. The doping Eu3 ions were partially reduced to Eu2 in Sr4Al14O25∶Eu and BaZnSiO4∶Eu prepared in an oxidizing atmosphere, N2 O2. However, such an abnormal reduction process could not be performed in Sr3Al2O6∶Eu, which was also prepared in an atmosphere of N2 O2. Moreover, even though Sr3Al2O6∶Eu was synthesized in a reducing condition CO, only part of the Eu3 ions was reduced to Eu2 . The existence of trivalent and divalent europium ions was confirmed by photoluminescent spectra. The different valence-change behaviors of europium ions in the hosts were attributed to the difference in host crystal structures. The higher the crystal structure stiffness, the easier the reduction process from Eu3 to Eu2 .     

A New Yellow Long Lasting Phosphor Y_2O_2S∶Ti

Longphosphorescencephosphorshaveattractedconsiderableattentioninrecenthalf century[1] becauseoftheirpotentialapplicationsinsuchfieldsaslumi nouspaint ,safetyindicatorinemergencycase ,etc[2～ 4 ] .Sincethediscoveryofalkali earthaluminatelonglastingphosphorsin 1996 [1] ,theyhavebeenstudiedextensivelyastheyhavebetterstabilityandlongerpersistenttimethanthesulfidephosphorswhichwerewidelyusedinmanycases .Uptonow ,poly crystallinephosphorsofblueCaAl2 O4 ∶ (Eu2 ,Nd3 ) ,greenSrAl2 O4 ∶(Eu2 ,…     

Cr3+离子在不同介质中的光谱特征及晶格场强度

研究Cr3+离子掺杂固体物质的制备工艺以及光谱特性有助于开发新的光学材料.本研究分别用提拉法技术生长了Cr3+∶BeAl2O4晶体, 用坩埚下降法技术生长了Cr3+∶LiNbO3晶体, 以及用高温熔融法技术研制了ZnO-Al2O3-SiO2微晶玻璃.获得了生长优质Cr3+∶BeAl2O4与Cr3+∶LiNbO3的工艺参数.分别测定与讨论了Cr3+离子在上述不同介质中的吸收光谱与荧光光谱特征.实验发现Cr3+离子在不同介质中, 其吸收光谱与荧光光谱的位置与形状在不同基质中发生很大的差异.在Cr3+∶BeAl2O4与Cr3+∶LiNbO3晶体中均观测到尖锐的R线荧光.从其相应的光谱特性大致估算了Cr3+离子在不同介质中的晶格场参数.从Dq/B值数据判断Cr3+∶BeAl2O4与Cr3+∶LiNbO3晶体属于强晶格场, Cr3+∶ZnO-Al2O3-SiO2与其微晶玻璃属于弱晶格场.     

Crystal Growth and Spectral Properties of Yb~(3+)∶KY(WO_4)_2

Diode pumpedsolid statelasers(DPSSL)based onYb3+dopedlasermediaaresuperiortotheDPSSL,basedonNd3+dopedinsomeapplications.Microchip lasercanbedevelopedbyYb3+dopedlasermaterial,whichisveryimportantforintegration,smallsize,andcompactnessofLDpumpedsolid statelaser[1～3].InYb3+∶KY(WO4)2(Yb∶KYW),Yb3+replacesY3+,whichdecreasesradiusdislocation,andhenceYb3+canbedopedwithhighconcentration[4].Compared withYb∶YAGandYb∶YCOB,Yb∶KYWhashighab sorptioncoefficient,lowquantumdefect,highabsor…     

黄蜀葵多糖的分子质量测定及单糖组成分析

采用凝胶渗透色谱法测定了4种黄蜀葵多糖的相对分子质量;选用糖分离柱(CarboPacPA200,3×250 mm),以10 mmol·L-1NaOH溶液为流动相、Au为工作电极、Ag/AgCI为参比电极的脉冲积分安培离子色谱法分离测定了4种多糖水解产生的单糖成分及相对含量.结果表明:凝胶渗透色谱法测定4种黄蜀葵多糖的重均分子量分别为4.23×103、6.11×105、4.47×103、6.01×105Da;离子色谱法检出4种多糖均含有半乳糖、葡萄糖、甘露糖以及极少量的阿拉伯糖,其中半乳糖、葡萄糖和甘露糖的物质量之比分别为0.29∶1.00∶0.41、0.56∶0.13∶1.00、0.10∶1.00∶0.11和0.55∶0.17∶1.00;检出限在1.63～2.80μg·L-1范围,相对标准偏差在2.55%～4.67%之间,样品加标回收率为95.8%～107.9%.     

Luminescence Properties of (Y, Gd)Al_3(BO_3)_4∶Eu ~(3 ) under VUV excitation

Thephosphorsasanimportantpartofplasmadis playpanel (PDP)deviceemitvisiblelightundervac uumultraviolet (VUV)excitationof 14 7nmand/or172nmfromXe/Hegasplasma[1] .Untilrecently ,Y2 O3∶Eu3 and (Y ,Gd)BO3∶Eu3 havebeenusedascommercialred emittingphosphorsforPDP[2 - 3] .Butthesematerialsstillhaveshortcomingstobeim proved :lowlightoutputofY2 O3∶Eu3 uponVUVex citationandbadcolorpurityof (Y ,Gd )BO3∶Eu3 [4～ 5] .AluminoborateshavestrongabsorptionintheVUVregion ,andexhibitexcellentma…     

Study on Luminescence Properties of High-Density Phosphors BiTaO4∶Pr3+ and BiTaO4

The photoluminescence properties of BiTaO4∶Pr3+ and BiTaO4 at room temperature were studied, and the infrared transmission and diffusion reflection spectra of BiTaO4 were measured. The photoluminescence spectrum of BiTaO4 peaks at about 420, 440 and 465 nm. There has an obvious excitation band from 330 to 370 nm. The photoluminescence spectrum of BiTaO4∶Pr3+ consists of the characteristic emission of Pr3+, and its main peak is at 606 nm from 3P0→3H6 transition of Pr3+. Its excitation spectrum consists of the wide band with maximum at 325 nm, the wide band in the range of 375～430 nm, and the characteristic excitation of Pr3+. The bands at 325 nm and 375～430 nm may be from the absorption of the charge transfer transition of the tantalate group and defect energy levels in its forbidden band, respectively. There is energy transfer from host to Pr3+. Because both the host density and photoluminescence peak intensity of BiTaO4∶Pr3+ are superior to PbWO4, BiTaO4∶Pr3+ may be a potential heavy scintillator.     

新型尾砂胶结剂胶结分级尾砂充填体强度研究

结合某矿山实际,采用实验室试验与数值模拟相结合的手段,研究了新型尾砂胶结剂胶结分级尾砂充填体力学强度特性及其作为采场顶板的稳定性.单轴抗压试验与巴西劈裂试验结果表明,灰砂比为1∶6、1∶12的新型尾砂胶结剂胶结分级尾砂充填体在7d、14 d、28 d、60 d养护龄期的抗压、抗拉强度,分别高于所对应灰砂比为1∶4、1∶8的42.5级水泥胶结分级尾砂充填体;并且灰砂比为1∶6、1∶12的新型尾砂胶结剂胶结分级尾砂充填体的早期抗压、抗拉强度均优于对应灰砂比为1∶4、1∶8的42.5级水泥胶结分级尾砂充填体;FLAC3D数值模拟结果表明:新型尾砂胶结剂胶结分级尾砂充填体,可以满足作为采场充填顶板的要求.     

纳米YVO4:Ln(Ln=Eu,Tm,Dy)发光粉的研制及与相应块体发光粉的光谱对比

采用络合溶胶-凝胶法合成出3种YVO4∶Ln(Ln= Eu,Tm,Dy)纳米发光粉,并且对纳米YVO4∶Ln与自合成的块体YVO4∶Ln的红外光谱(FTIR),荧光光谱和X-射线衍射以及粒径的分布进行了对比研究.实验结果证明,当钒基稀土发光材料粒径达到纳米级以后,由于纳米粒子的一些特性,导致发光材料的光谱与块体材料相比有了较大的不同,出现了不同程度的蓝移现象.并且纳米发光材料的发光强度较块体发光材料的强度有一定程度的增强.     

新型废水絮凝剂的合成及稳定性的研究

合成了一种新型微交联阳离子絮凝剂FHAD,讨论了量比n[丙烯酰胺(AM)]n∶[二甲基二烯丙基氯化铵(DADAAC)]、n[聚胺(CPA)]n∶[丙烯酰胺与二甲基二烯丙基氯化铵共聚物(PDA)]、PDA分子质量对产品稳定性的影响.用此絮凝剂处理染料废水具有较好的脱色和去COD效果,并确定了最佳配比:n(AM)n∶(DADAAC)为69∶4,n(CPA)n∶(PDA)为11∶.     

Macro and Micro Behaviors of Low Alloyed TRIP780 Steel with Different Biaxial Proportional Loading

To investigate the macro and micro behaviors of TRIP(transformation induced plasticity)steel under biaxial loading,experiment and finite element simulation were carried out for TRIP780 steel under proportional biaxial tension with displacement ratio of 1∶1,2∶1,3∶1 and 4∶1,respectively.The results show that cruciform specimens of TRIP780 steel fractured under proportional biaxial stretching when effective strain was about 1.5%,and fracture was always generated on the cross arm or cross links.During biaxial tension,stress and strain components in xand ydirections of the center of the samples have the same nonlinear developing tendency,decreasing in one direction and increasing in another direction.Equal biaxial stretching stress state was helpful for retained austenitemartensite transformation than the other biaxial stress state.With increasing displacement ratio(DR)from 1∶1to 4∶1,corresponding stress distributed unevenly on the yield ellipse from 30° to 60° in the first quadrant of stress space and corresponding retained austenite volume fraction distributed symmetrically in bow tie format.     

7020挤压铝合金T4及T6状态金相腐蚀效果研究

为了确定挤压态7020铝合金T4及T6状态下的最佳腐蚀方法,对挤压态7020铝合金T4及T6状态分别进行不同类型腐蚀剂的腐蚀处理。经试验得出,氢氟酸溶液=1∶1对于T4及T6状态下7020铝合金的晶界腐蚀效果最好,腐蚀后晶界清晰,组织晶粒明显。磷酸溶液∶水=1∶9,硫酸溶液∶水=1∶9~2∶8,硝酸溶液∶水=1∶3腐蚀后的T4及T6状态下的7020铝合金组织第二相分布明显。     

氧化物熔盐电沉积二硼化钛镀层的研究

分别采用脉冲电源和直流电源,利用TiO2 B2 O3 LiF KF熔盐体系,在石墨基体上电沉积制备了TiB2 镀层。在实验中,考察了直流电流密度、脉冲宽度、脉冲间隔、脉冲电流幅度等条件对TiB2 镀层性能的影响。实验结果表明:采用脉冲电沉积得到的镀层性能优于直流电沉积。在本实验参数下(摩尔比TiO2 ∶B2 O3∶KF∶LiF =0 .0 6∶0 .4∶0 .74∶0 .8,温度80 0℃,脉冲宽度7.5ms ,脉冲间隔2 .5ms,电流密度0 .6A·cm- 2 ,电沉积时间5 0min)得到的TiB2 镀层表面平整,有金属光泽,结构致密,晶粒细小,与基体的结合力良好。     

高碱性脉石低品位混合镍矿氧压浸出行为与机制研究

研究了氧压氨浸条件下高碱性脉石低品位混合镍矿在NH3-(NH4)2SO4-H2O体系中的浸出行为与机制.结果表明:在氧分压1.3 MPa、浸出温度120℃、总氨浓度8 mol/L、c(NH3)∶c((NH4)2SO4)=1.5∶1、液固体积质量比10∶1、浸出时间2h条件下,镍浸出率达70.86％,其中以氧化镍和硫化镍形式存在的镍浸出率达93％,而赋存于硅酸盐晶格中的镍因热力学原因不能被浸出.     

Tm3+对甲基苯甲酰甲基亚砜高氯酸铽配合物的荧光增强效应

合成了六种不同掺杂比例的稀土高氯酸盐(铽掺铥)与甲基苯甲酰甲基亚砜的固态配合物,经元素分析、稀土络合滴定确定其组成为(TbxTmy)(ClO4)3·L5·C2H5OH(x∶y=1.000∶0.000,0.999∶0.001,0.995∶0.005,0.990∶0.010, 0.950∶0.050,0.900∶0.100).荧光光谱测定结果表明,将铥掺入铽后,可大大提高配合物中铽离子的荧光发射强度,当x∶y=0.995∶0.005时敏化强度最大,可使配合物的荧光强度增加到147%.并且在本文所研究的掺杂比例范围内,配合物中Tm3+对Tb3+的发光一直起敏化作用.