Influence of Ga~(3 ) on Photoluminescence of Ce~(3 )

ＩｎｆｌｕｅｎｃｅｏｆＧａ３＋ｏｎＰｈｏｔｏｌｕｍｉｎｅｓｃｅｎｃｅｏｆＣｅ３＋ＸｕＣｈｕｎｘｉａｎｇ（徐春祥），ＬｏｕＺｈｉｄｏｎｇ（娄志东）（ＩｎｓｔｉｔｕｔｅｏｆＭａｔｅｒｉａｌＰｈｙｓｉｃｓ，ＴｉａｎｊｉｎＩｎｓｔｉｔｕｔｅｏｆＴｅｃｈｎｏ...     

Thermal Expansion of LaCoO3

High-temperature X-ray diffraction(HTXRD)measurements of LaCoO3 powder was carried out in a temperature range from 298 to 1273 K.The experimental data obtained were adopted to evaluate the lattice parameters and cell volume.In this temperature range,the linear and volume expansion coefficients calculated using these cell parameters are 24.160～23.610×10-6·K-1 and 59.601～63.218×10-6·K-1 respectively.There is no discontinuity found in the cell parameters through the proposed first-order transition at 1210 K.     

Crystal Structure of RbYbI_3

ＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆＲｂＹｂＩ３ＷａｎｇＭｅｉｔｉａｎ（王梅天），ＷａｎｇＳｈｉｈｕａ（王世华）（ＤｅｐａｒｔｅｍｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＢｅｉｊｉｎｇＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ，Ｂｅｉｊｉｎｇ１００８７５，Ｃｈｉｎａ...     

Thermokinetics of Liquid-Liquid Reaction of Dy（NO3 ）3 with Histidine

The thermokinetics of liquid-liquid reaction of dysprosium nitrate with histidine were studied using a microcalorimeter. On the basis of experimental and calculated results, threethermodynamic parameters (the activation enthalpy, the activation entropy and the activation free enegy),the rate constant, three kinetic parameters (the activation energy, the pre-exponential constant and the reaction order) wereobtained. On the basis of thermodynamics and kinetics, the for marion reaction of the complex was discussed.     

Effect of Addition of Sm_2O_3 on Property of CuO-γ-Al_2O_3 Catalyst

ＥｆｅｃｔｏｆＡｄｄｉｔｉｏｎｏｆＳｍ２Ｏ３ｏｎＰｒｏｐｅｒｔｙｏｆＣｕＯγＡｌ２Ｏ３ＣａｔａｌｙｓｔＪｉａｎｇＸｉａｏｙｕａｎ（蒋晓原），ＺｈｏｕＲｅｎｘｉａｎ（周仁贤），ＭａｏＪｉａｎｘｉｎ（毛建新），ＺｈｅｎｇＸｉａｏｍｉｎｇ（郑小明）（...     

Effect of Nd^3＋ on Photosynthesis of Spinach

The effect of Nd^3 on the photosynthesis and the growth of spinach was studied. The results show that Nd^3 improves the growth of spinach and increases chlorophyll content and photosynthetic rate. UV-Vis spectrum indicates that the Soret band of chl-a in spinach with NdCl3 treatment is blue shifted by 2 nm, and the Q band is red shifted by 1 nm, and the ratio of Soret band intensity and Q band intensity increases. FT-IR spectra show that the peak of porphyrin ring in chl-a of spinach with NdCl3 treatment is widened, suggesting that the formation of Nd^3 -chl-a. Treated by NdCl3, the fluorescence emission peak of PSⅡ in spinach leaves is blue shifted by 12 nm and the intensity declines obviously, indicating that Nd^3 is bound to the PSⅡ protein-pigment complex and the electron transfer rate increases.     

Effects of Ce3＋ , Nd3＋ , Gd3＋, Tb3＋ and Lu3＋ ions on Formation of CaCO3

The effects of lanthanides at various concentrations on CaCO3 crystal growth were studied by X-ray diffraction (XRD), infrared spectra (IR), X-ray photoelectric energy spectra (XPS) and inductively coupled plasma mtms spectrometry (ICP-MS). It was found that the calcite, a stable form of CaCO3 in thermodynamics, is the predominant species. The research indicates that lanthanide ions (Ln3 ) can partly substitute the Ca2 in the lattice of CaCO3 crystals, and change the crystal characterization and direct the ordinal growth of CaCO3 crystals.     

Mechanical Activation-Assisted Synthesis of Nd-BaPbO3

ThesimpleperovskiteBaPbO3hasbeenreportedtohavehighelectricalconductivityandorthorhombicsymmetry[1～ 3] .Matherssetal .[4 ] reportedthehighconductivityofthismaterialoriginatesfromtheforma tionofabroadbandduetomixingoflead 6sandoxy gen 2pstates .Substitutionand/ornonstoichiometryinBaPbO3induceinterestingelectricalproperties .Forexample ,Sleightetal .[3] foundthesuperconductivityofBaPb1-xBixO3intherangeofx =0 .0 5～ 0 .3in1975 .IncreasingattentionhasbeenfocusedonBaP bO3asacomponentofthemate…     

Structural Characteristic of AREI_3 Compounds

The structure of AREI_3 is reported in this paper.Their crystal structures,which includeAREI_3(A=K,Rb,Cs;RE=Sm,Eu,Yb,Tm) were determined by X-ray powder diffraction method,Gui-nier technique was used.CsEuI_3 was investigated by electron microscopy to confirm the polytype ofAREI_3(SrCeO_3-type,Pmmm) observed in the X-ray diffraction experiments.The values as a function of structure type show that the structure of AREI_3 are different from that ofother halides of AREX_3(X=F,Cl,Br)     

Effect of Ln3＋ on Inhibition of Tobacco RuBPcase

Ｉｔｗａｓｐｒｏｖｅｄｂｙｐｒｅｖｉｏｕｓｗｏｒｋｓ[1] ｔｈａｔｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓｐｒｏｍｏｔｅｔｈｅｇｒｏｗｔｈａｎｄｄｅ ｖｅｌｏｐｍｅｎｔｏｆｐｌａｎｔｓａｎｄｉｎｃｒｅａｓｅｔｈｅｙｉｅｌｄｏｆｃｒｏｐｓａｔｌｏｗｃｏｎｃｅｎｔｒａｔｉｏｎ ,ｂｕｔｗｈｅｎｔｈｅｃｏｎ ｃｅｎｔｒａｔｉｏｎｉｓｈｉｇｈ ,ｔｈｅｙｗｉｌｌｉｎｈｉｂｉｔｔｈｅｇｒｏｗｔｈｏｆｐｌａｎｔｓ .Ｉｔｗａｓａｌｓｏｐｒｏｖｅｄ[2 ,3] ｔｈａｔｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｓｅｘｈｉｂｉｔｂｏｔｈｐｏｓ…     

Effects of Concentration of La~(3 ) Vacancies in LaMnO_(3 λ) on the Catalytic Activity of Oxidation of CO

ＥｆｅｃｔｓｏｆＣｏｎｃｅｎｔｒａｔｉｏｎｏｆＬａ３＋ＶａｃａｎｃｉｅｓｉｎＬａＭｎＯ３＋λｏｎｔｈｅＣａｔａｌｙｔｉｃＡｃｔｉｖｉｔｙｏｆＯｘｉｄａｔｉｏｎｏｆＣＯＳｕｎＹｏｎｇａｎ（孙永安），ＺｈａｎｇＷｅｎｔａｏ（张文韬）（Ｄｅｐａｒｔｍｅｎ...     

Measurement of Densities and Surface Tensions of NaCl-KCl-ScCl_3 System

Scandiumpossessesexcellentphysicochemi-calproperties.WhenalittleofScisaddedintoAlalloy,thestrengthandhardnessofAlalloycanbeincreasedremarkably,andthesyntheticmechanicalpropertiescanbeimprovedlarge-ly['~sJ-Especially,Al-ScalloyhasexcellentsuI:rplasticalproperty,andtheelongationofAlalloywith~0.5%Sccanreachupt01lO0q'bymeans0fsuperplasticforming['j.Inaddition,becausethereisonlyalittledifferenceindensityofAlandSc,Al-Scalloywithhighspecialstrength(theratioofthestrengthtotheweight)canbeprepared…     

Structure of Laser Depositing of Al_2O_3 Coating

Ｔｈｅｒｅａｒｅｔｈｒｅｅｍａｉｎｆｏｒｍｓｏｆａｌｕｍｉｎａ，ｎａｍｅｌｙα－Ａｌ２Ｏ３，β－Ａｌ２Ｏ３ａｎｄγ－Ａｌ２Ｏ３．Ｐｅｒｆｏｒｍａｎｃｅｓｏｆα－Ａｌ２Ｏ３ａｒｅｔｈｅｂｅｓｔａｍｏｎｇｔｈｅｍ：ｔｈｅｃｏｅｆｉｃｉｅｎｔｏｆｅｘ－ｐａ...     

Influence of B2O3 on Spectroscopic Properties of Er^3＋/Yb^3＋ Co-Doped Tungsten-Tellurite Glasses

A series of novel Er^3＋/Yb^3＋ co-doped （85- x ） TeO2-15WO3-xB2O3 （TWB;x=2%,5%,8%（mole fraction） ） glasses were prepared. Influence of B203 on the spectroscopic properties of Er^3＋/Yb^3＋ co-doped tungsten-tellurite glasses were investigated. It is found that the intensity of 1.5μm fluorescence, lifetime of the ^4I13/2 level and upconversion fluorescence all decrease with the increase of B2O3 content. The product of full width at half maximum （FWHM） and stimulated emission cross-section （σe^peak） of Er^3＋ ：^4I13/2→^4I15/2 transition has an optimum when B203 is 5% （mole fraction）. The emission spectra of Er^3＋ ： ^4I13/2→^4I15/2 transition was analyzed using peak-fit routine, and an equivalent four-level system was proposed to estimate the stark splitting for the 411512 and ^4I13/2 levels of Er^3＋ ions in TWB glasses at room temperature.     

Investigation of Modification Effect of B2O3 Component on Optical Spectroscopy of Er^3＋ Doped Tellurite Glasses

To investigate the modification effect of the B2O3 component on tellurite glass, a series of glasses with a composition of xB2O3-（80-x）TeO2-10ZnO-10Na20 （x = 0, 10, 20, 30, 40, 50, 60, 70, 80） and an additional amount of 0.5% Er2Os（in molar） were prepared. The refractive index, the absorption edge of the host, the J-O parameters of Er^3＋ , the fluorescent decay time, the bandwidth, and the quantum efficiency for the 4Ⅰ13/2→4Ⅰ15/2 transition were obtained theoretically and experimentally. These results indicated that the introduction of B2O3 modified the performance of the tellurite glass. For example, with increasing content of B2O3, the refractive index of the host decreases from 1.9 to 1.5, the absorption edge of the host shifted toward the blue regime, the intensity parameter Ω6 changed from 1.08 × 10^-20（for the pure tellurite glass） to 1.98 ×10^-20 cm^2（for the pure borate glass）, the bandwidth of the 4Ⅰ13/2→4Ⅰ15/2 transition increased, and the quantum efficiency of the 4Ⅰ13/2→4Ⅰ15/2 transition decreased.     

Influence of Al4C3 Particles on Grain Refinement of Mg–3Al Alloys

Al?CSi/Al₄C₃ master alloy has been developed by reacting the SiC particles in Al melt. The extent of SiC conversion to Al₄C₃ in the Al?CSi/Al₄C₃ master alloy has been calculated using optical emission spectroscopy. Experimental results indicated that only 70?% of SiC particles have been converted into Al₄C₃ after the reaction between Al and SiC in Al/5?wt% SiC_p composites at 900?°C. The grain refining efficiency of Al?CSi/Al₄C₃ master alloy has been assessed by adding this into the Mg?C3Al alloy. Grain size of Mg?C3Al alloy has been significantly refined from 480 to 220???m by the addition of 0.07?wt% of Al₄C₃ particles in the form of Al?CSi/Al₄C₃ master alloy.     

Effect of Bi2O3 Additives on Properties of La0.7Ca0.3CrO3

Lanthanum chromites doped with alkaline earthmetals (Ca or Sr) have been widely accepted as candi dates for interconnection materials in high temperaturesolid oxide fuel cells (SOFCs)[1,2]. It can satisfy mostof the requirements for SOFC, such as h…     

Influence of In3＋ ions concentration on spectroscopic properties of Ho：LiNbO3 crystals

In:Ho:LiNbO3 crystals doped with various concentrations of In3+(0, 1 mol.%, 3 mol.%, 5 mol.%), fixed concentrations of Ho3+ (1 mol.%) were grown by Czochralski method. The X-ray powder diffraction, infrared and UV-visible absorption spectra were measured and modified. Judd-Ofelt approach was employed to study the effect of In doping on spectroscopic properties of Ho:LiNbO3 crystals. In concentrations in crystals were analyzed by an inductively coupled plasma optical emission spectrometry (ICP-OE/MS). For In (3 mol.%):Ho (1 mol.%):LiNbO3 crystal, the obtained intensity parameters were: Ω2=9.6563, Ω4=4.2195, Ω6=14.1526. The results showed that the Ω2 and Ω6 parameters increased with the increase of In3+ concentration. When the In doping concentration was up to 5 mol.%, Ω2 and Ω6 suddenly decreased. In2O3 incorporation had a strong effect on the radiative lifetime, but had less influence on fluorescence branching ratios. The effective distribution coefficient of In3+ in In:Ho:LiNbO3 crystals was less than 1 and increased with increasing concentration of In3+ in the melt.     

Effect of Crystallization of Li2O-Al2O3-SiO2 Glasses on Luminescence Properties of Nd^3＋ Ions

In the field of solid-state lasers ,it is generallyconsidered that laser action can only be obtained insingle crystals or glasses ,because they ensure lowab-sorption or diffusion of light , which is required toovercome laser threshold . Now, the number of thehost materials has increased withthe addition of a newmaterial group ,glass-ceramics .Transparent glass-ce-ramics may advantageously replace glass lasers in sev-eral applications ranging from microchip lasers andamplifying optical fibers t…     

Transformation of α-Fe2O3 to Fe3O4 Realized by Mechanochemical Reaction of α-Fe2O3 and SrCO3

A transformation from ??-Fe₂O₃ with rhombohedral structure to Fe₃O₄ with spinel face-centered cubic (fcc) structure was realized by ball milling the mixture of SrCO₃ and ??-Fe₂O₃ powders with molar ratio of 1:3 under ambient air in the current work, but it was not observed by ball milling the ??-Fe₂O₃ powders. The transformation is due to a mechanochemical reaction between SrCO₃ and ??-Fe₂O₃ in the milling process, and the ??-Fe₂O₃ catalyzes the decomposition of SrCO₃, while the decomposition promotes the transformation of ??-Fe₂O₃ to Fe₃O₄. X-ray diffraction, X-ray photoelectron spectrometry, and magnetic measurements indicate that the transformation finishes completely upon milling of 120?hours, and the mixture milled for 120?hours consists of Fe₃O₄ and a Sr element. However, Sr does not incorporate into the Fe₃O₄ but exists in grain boundary of the Fe₃O₄ in a form of a Sr-O bond. It is found that the product obtained by ball milling the mixture is different from that prepared by sintering the mixture at atmospheric pressure, which product is SrFeO_2.97 with cubic structure. The mechanism of the transformation and origin of difference in products obtained in the ball milling and sintering processes are also discussed in the current work.