Quenching Photoluminescence of Eu(III) by Cu(II) in ZnO:Eu3++Cu2+ Compounds by Solution Combustion Method

In this study Cu2++Eu3+ co-doped ZnO(ZnO/Cu2++Eu3+) solid solution powders were synthesized by solution combustion method using as oxidant agent zinc nitrate hexahydrate and as fuel urea;the Cu2+ concentrations were 0, 1, 2, 3, 10, and 20 %Wt;the Eu3+ ion concentration was fixed in 3%Wt. The samples after were annealed at 900°C by 20 h in air. The structural results showed the largely presence of a wurtzite solid solution of Cu2++Eu3+doped ZnO, at high Cu2+ doping CuO and Eu2CuO4 phases are also present. Morphological properties were analyzed using scanning electron microscopy (SEM) technique. However it is important to remark that the Cu2+ ions suppress the Eu3+ ion photoluminescence (PL) by means of an overlap mechanism between Cu2+ absorption band and Eu3+emission band (e.g. 5D0→7F2) of the Eu3+ emission spectra.

Determination of Apparent Formation Constants of Eu(III) with Humic Substances by Ion Selective Liquid Membrane Electrode

This is the novel measurement of the apparent formation constants of trivalent lanthanide with humic substances by potentiometric titration using an ion selective electrode (ISE) consisting of bis(diphenylphosphoryl)methane as an ionophore. The ISE prepared exhibited a Nernstian response to the Eu3+ concentration in the test solutions in the presence of humic acid and fulvic acid. The effect of the solution conditions, including the pH, initial metal and humic substance concentrations, and ionic strength, on the formation constants was examined. The present formation constants were compared with the reported data using solvent extraction method.

Solvent extraction of uranium(VI) and europium(III) from nitrate media by picolinamide

The solvent extraction of uranium(VI) and europium(III) from nitric acid solution was studied with pi- colinamide dissolved in ethylene dichloride. The distribution ratios of U(VI) and Eu(III) as a function of aqueous HNO3 concentration , extractant concentration in organic phase and temperature as well as the salting-out agent con- centration have been measured. The experiment results show that picolinamide has higher extractability for U(VI) than for Eu(III). The composition of extracted species, equilibrium constants and enthalpies of extraction reaction have also been presented.

Adsorption behavior of ^(241)Am(Ⅲ) and Eu(Ⅲ) by silica/polymer-based isoHex-BTP adsorbent from nitric acid solution

The adsorption behavior of241Am(Ⅲ) and Eu(Ⅲ) by silica/polymer-based iso Hex-BTP adsorbent(iso HexBTP/Si O2-P) was investigated by a batch experiment method. iso Hex-BTP/Si O2-P exhibited high affinity and selectivity for241Am(Ⅲ) over152Eu(Ⅲ) in 2–4 mol/dm3 nitric acid solutions. Within the experimental contact time range of 0.5–24 h, iso Hex-BTP/Si O2-P showed high selectivity for241Am(Ⅲ) compared to152Eu(Ⅲ) in3 mol/dm3 nitric acid solution. However, the adsorption kinetics of241Am(Ⅲ) and152Eu(Ⅲ) was slow. Eu(Ⅲ)adsorption followed the pseudo-second-order kinetic model, indicating chemical adsorption as the rate-limiting step of the adsorption process. And the adsorption agreed well with the Langmuir adsorption model at various temperatures. The adsorption kinetics and isotherm data indicated that the equilibrium adsorption capacity, the adsorption rate, the maximum adsorption capacity and the adsorption affinity, increased with temperature. The thermodynamic parameters, negative change in Gibbs free energy, and positive change in enthalpy and entropy,suggested that the adsorption of Eu(Ⅲ) was spontaneous and endothermic process with an increase of entropy.

Removal of Chromium(III) from the Waste Solution of an Indian Tannery by Amberlite IR 120 Resin

The extraction of chromium(III) from a model waste solution and also from a waste solution of an Indian tannery with Amberlite IR 120 resin is described, and the performance of this resin is compared with other similar resins. The parameters that were optimized include effect of mixing time, pH, loading and elution behaviours of chromium(III) for this resin. Sorption of chromium(III) on Amberlite IR 120 followed Freundlich isotherm and Langmuir isotherm model, and the maximum sorption capacity was determined to be 142.86 mg Cr(III)/g of the resin. Higher Freundlich constant (Kf) values (6.30 and 13.46 for aqueous feed of 500 and 1000 ppm Cr(III)) indicated strong chemical interaction through ion exchange mechanism of the metal ion with the resin. The kinetic data showed good fit to the Lagergren first order model for extraction of chromium(III). Desorption of chromium(III) from the loaded resin increased with the increase in concentration of eluent (5-20% H2SO4). With 20% (v/v) sulphuric acid solution 94% chromium(III) was eluted in three stages. Elution of the Cr(III) in the column experiments was however, found to be lower (82%) than that of the shake flask data. In case of Indian tannery’s waste solution, it was observed that almost total chromium was extracted in four stages with Amberlite IR 120.

A Highly Luminous LiCaPO₄:Eu²⁺Phosphor Synthesized by a Solution Method Employing a Water-Soluble Phosphate Ester

A LiCaPO4:Eu2+ phosphor with high photoluminescence was synthesized using a polymerizable complex (PC) method employing a water-soluble polyethylene glycol-conjugated phosphate ester (PEG-P). PEG-P could be obtained from a reaction among polyethylene glycol 300, phosphorus pentoxide, and pyrophosphoric acid. The PEG-P prepared was stable in an aqueous condition. A transparent solution and gel were obtained when the PEG-P was used as a source of P during the PC method, whereas the use of H3PO4 caused an undesirable precipitate. The LiCaPO4:Eu2+ obtained via the PC method employing the PEG-P showed higher emission intensity than those synthesized by a solid state reaction method and the PC method employing H3PO4. The high luminescence properties of the sample synthesized using the PEG-P may be attributed to high homogeneity of constituents in the sample.

基于改进NSGA-III算法的多无人机协同目标分配

武器-目标分配问题是战场环境下无人机对敌方执行打击任务的关键,其目的是基于目标的威胁、价值和我方武器的毁伤概率,寻找合理的武器目标分配方案,以提高作战效率。针对当前多目标优化算法解决静态武器-目标分配问题时收敛速度慢、收敛稳定性差,难以适应当前战场高度实时性的问题,提出一种改进的基于参考点的非支配排序遗传算法。通过二进制编码打击方案并优化初始种群,引入自适应变异与交叉策略以及种群寻优更新策略,基于对战场态势进行评估得到的威胁矩阵和优势矩阵,种群多次迭代后生成目标打击方案。最后计算满足约束条件的Pareto解集,并将Pareto前沿中的相对最优解作为多无人机的打击方案。多次实验证明,在较好情况下改进算法相比于原始算法的收敛时间减少46.74%,目标威胁值降低50.5%,总飞行航程减少26.46%,杀伤目标数增加11.76%,证明该算法在解决多无人机空对地打击任务目标分配问题时具有合理性和高效性。

Role of Microstructure and Spectrum Features on the Catalysis Effect of Ce1-x(Nd0.5Eu0.5)xO2-δSolid Solutions

Nanosized Ce^1-x）（Nd^0.5）Eu^0.5））xO^2-δ） solid solutions（x = 0.00-0.20） were synthesized by means of hydrothermal method.Then the solid solutions were ball milled with Mg2Ni and Ni powders for 20 h to get the Mg2Ni–Ni–5 mol% Ce^1-x）（Nd^0.5）Eu^0.5））xO^2-δ） composites.The structures and spectrum characteristics of the Ce^1-x）（Nd^0.5）Eu^0.5））xO^2-δ） solid solutions catalysts were analyzed systemically.XRD results showed that the doped samples exhibited single phase of CeO2 fluorite structure.The cell parameters and cell volumes were increased with increasing the doped content.Raman spectrum revealed that the peak position of F^2g mode shift to higher wavenumbers and the peak corresponding to oxygen vacancies were observed distinctly for the doped samples.UV-Vis technique indicated that the absorption peaks of Eu^3＋ and Nd^3＋ ions appeared; the bandgap energy was decreased linearly.The electrochemical and kinetic properties of the Mg2Ni–Ni–5 mol% Ce1-x（Nd0.5Eu0.5xO2-δ composites were measured.The maximum discharge capacity was increased from 722.3 mA h/g for x = 0.00 to 819.7 mA h/g for x = 0.16,and the cycle stability S20 increased from 25.0%（x = 0.00） to 42.2%（x = 0.20）.The kinetic measurement proved that the catalytic activity of composite surfaces and the hydrogen diffusion rate were improved for the composites with doped catalysts,especially for the composites with x = 0.16 and x = 0.20.The catalysis mechanism was analyzed from the point of microstructure and spectrum features of the Ce1-x（Nd0.5Eu0.5）xO2-δ solid solutions.

红色超敏LaAlO_(3)∶Eu^(3+)纳米荧光粉的X射线激发光谱及其CIE色度特性

采用溶液燃烧合成法制备新型红色超敏La AOl_(3)∶Eu^(3+)纳米荧光粉,合成的La AOl_(3)∶Eu^(3+)材料具备纯R3c(No.167)结构.采用光谱学方法,研究La AOl_(3)∶Eu^(3+)纳米荧光粉的X射线激发光谱性质.结果显示,在X射线激发下,La AOl_(3)∶Eu^(3+)纳米荧光粉发射出很强的红色荧光,谱带中心波长位于620nm处,发光的淬灭浓度是6.0mol%.CIE色度研究表明,样品具有优良的红色荧光发射特性且浓度效应对色调和色纯度影响较小.说明合成的荧光粉可作为高效闪烁体,在超紫外LEDs和辐射探测等领域有重要的应用价值.

Efficient removal of Al(Ⅲ)and P507 from high concentration MgCl_(2)solution based on in-situ reaction strategy

For a highly efficient recycling of a wastewater containing a high concentration of MgCl_(2),Al(Ⅲ)and P507 were scheduled to be removed in advance.In this study,the in-situ removal of Al(Ⅲ)and P507 from a high concentration MgCl_(2)solution at different pH values and Al/P molar ratios was investigated.The results showed that P507 formed organic complexes of Al_(x)(OH)_y^(Z+)-P507 at pH of 2.0-4.0.At pH of 4.0-5.0,Al(Ⅲ)precipitated and transferred into Al(OH)_(3)with a flocculent amorphous morphology.Active sites on the Al(OH)_(3)surface enhanced the removal efficiency of P507.At pH of 6.0-6.5,Al(Ⅲ)and Mg(Ⅱ)formed layered crystalline Al(OH)_(3)and MgAl_(2)(OH)_(8with)small pore channels and fewer active sites,resulting in a reduced removal efficiency of P507.When the Al/P molar ratio exceeded 13 and the pH was between 4.0 and 5.0,the removal rates of both Al(Ⅲ)and P507 were higher than98%,while the concentration loss of Mg(Ⅱ)was only 0.2%-0.9%.

溶胶–凝胶法制备 Eu^3＋掺杂 BiVO4及其可见光光催化性能

采用柠檬酸络合溶胶–凝胶法制备了Eu3+掺杂BiVO4新型光催化剂,通过XPS、XRD、SEM、BET和UV-Vis等手段对其进行表征和分析。并以甲基橙为模拟污染物,考察了BiVO4的可见光催化活性。结果表明,Eu3+掺杂前后BiVO4均为单斜白钨矿型,无其他杂质相生成,且由于掺杂Eu3+,晶体中V4+和氧空缺增多。掺杂后样品光吸收性能发生红移,但掺杂对其形貌和比表面积改变较小。Eu3+掺杂有效提高了BiVO4的可见光催化活性,当Eu3+掺杂量为0.2mol%时,BiVO4光催化效率最高,50 min内对甲基橙溶液的脱色率达95%,比纯BiVO4提高了62%左右。

导向剂法合成EU-1分子筛

将导向剂法引入EU-1分子筛合成体系，所加入的导向剂为自主研发的硅铝酸盐溶胶（或凝胶）。合成导向剂时，仅在其中加入少量有机模板剂溴化六甲双铵（HMBr2），而在配制反应混合物时不再加入HMBr2。按照m（SiO2）：m（Al2O3）：m（Na2O）：m（HMBr2）：m（H2O）为（40～50）：1：（2．0～4．5）：（9～12）：（60～80）质量比配制导向剂，适宜的陈化温度为370～450K，陈化时间为18～24h。合成EU-1分子筛适宜的反应混合物质量比m（SiO2）：m（Al2O3）：m（Na2O）：m（H2O）为（30～40）：1：（1．7～4．9）：（50～70），导向剂用量为8％～10％，晶化时间为2～3d，温度区间为430-450K。采用XRD、SEM、和IR等表征手段对样品进行表征。结果表明，采用该法成功地合成了高纯度、高结晶度的EU-1分子筛，且模板剂用量较常规合成法降低70％以上，降低了制造成本。

Eu(Ⅲ)溶液对膨润土-砂混合物渗透性能影响研究

在高放废物处置库长期运营过程中包封容器将发生破坏,核素会向外界迁移,缓冲回填材料的水力传导系数是评价处置库工程屏障性能的重要指标。采用柔性壁渗透仪,研究2.0×10-5 mol/L的Eu(III)溶液作为渗入液时膨润土-砂混合物的渗透特性。结果表明,膨润土-砂混合物的水力传导系数K=(2.07~5.23)×10-10 cm/s;在0~50%掺砂率范围内,膨润土-砂混合物吸水膨胀过程中渗透性能随掺砂率增大时没有明显的变化,能够满足高放废物处置库缓冲回填材料低渗透性的要求。使用有效黏土密度的概念,得到膨润土-砂混合物的体积膨胀率随初始有效黏土密度的增大呈指数增大的趋势;混合物水力传导系数的对数值与有效黏土密度存在良好的线性衰减关系;与蒸馏水相比,渗入液(ECDD)为2.0×10-5 mol/L的Eu(III)溶液时,膨润土-砂混合物的水力传导系数较小,可能是由于渗入液黏滞性的影响。

Ce_(1-x)Eu_xO_(2-δ)(x=0.05～0.50)固溶体的溶胶-凝胶法合成与性质研究

利用溶胶 -凝胶方法合成了固溶体Ce1 -xEuxO2 -δ,通过XRD ,Raman ,XPS和交流阻抗谱系统研究了固溶体Ce1 -x EuxO2 -δ的结构 ,确定了稀土离子价态及掺杂对CeO2 基电解质电性能的影响 .XPS分析表明固溶体Ce1 -xEuxO2 -δ中 ,Eu离子价态为 +3价 ,Ce离子主要以Ce4+ 离子形式存在 ,阻抗谱测试表明低价离子掺杂使固溶体Ce1 -xEuxO2 -δ的导电率得到很大提高 ,导电率x =0 .2时达到最大值σ60 0℃ =2 .87× 10 -3 S·cm-1 .导电活化能为Ea=0 .72eV .

Eu-TTA体系测定条件的优化及其在小麦代谢研究中的应用

研究了铕(Ⅲ)-TTA(邻-A噻吩甲酰三氟丙酮)体系在有机溶剂和邻菲啰啉衍生物存在下的荧光性质,发现醇类有机溶剂能使Eu(Ⅲ)-TTA体系荧光强度大幅度提高;三种邻菲啰啉衍生物中,4,7-二苯基-2,9-二甲基-1,10-邻菲啰啉的加入也能提高体系灵敏度,优化了反应条件,并用此法研究了小麦根施Eu^(3+)数天后,Eu^(3+)在根和叶片细胞膜和细胞内的分布定位,为稀土元素的植物代谢研究提供了一种重要的辅助研究手段.

非自发成核体系合成EU-1分子筛的研究

通过添加自主发明的液态晶种，首次在非自发成核体系中制备了EU一1沸石分子筛，并采用xRD，SEM，IR，TG—DTG等手段对样品进行表征。考察了水的添加量、硅铝摩尔比、碱硅摩尔比、晶化温度、晶化时间等因素对合成的影响，获得了合成EU-1分子筛适宜的配比n（SiO2）：n（Al2O3）。n（Na2O）：n（H2O）=（30～80）：1：（1．82～5．44）：（691～1000），晶化温度为453K，晶化时间为48～120h。液态晶种法合成的分子筛为形貌规整、轮廓清晰的薄片层状结构。采用此方法合成的EU-1中模板剂的使用量仅为常规法的1／5，在很大程度上降低了生产成本，具有潜在的工业化应用前景。

Eu(Ⅲ)在泥炭上的吸附行为研究

采用静态法研究了Eu(Ⅲ)在泥炭上的吸附行为。探讨了固液比、离子强度、pH、腐殖酸等因素对吸附的影响,并测定了不同温度下的吸附等温线。实验结果表明,pH对Eu(Ⅲ)吸附过程影响较大;离子强度有一定影响;低pH情况下腐殖酸会促进Eu(Ⅲ)吸附的进行,高pH情况下腐殖酸会抑制吸附的进行;吸附反应的吉布斯自由能变小于零说明吸附过程自发进行;吸附过程符合Freundlich吸附模型。

SrAl_2O_4∶Eu^(2+),Dy^(3+)磷光粉低成本制备工艺及发光性能研究

以工业铝酸钠溶液制备的氢氧化铝为铝基原料,采用高温固相反应法合成了SrAl2O4∶Eu2+,Dy3+磷光粉,考察了稀土掺杂量、烧结温度及硼酸加入量对其发光性能、激发光谱及发射光谱的影响,并通过XRD谱及余辉衰减曲线对最佳工艺条件下制备的样品进行表征。结果表明,当稀土掺杂量x(Eu)=3%、x(Dy)=3%,烧结温度为1 300℃,烧结时间为4h,硼酸加入量w(H3BO3)=9%时,所制备磷光粉样品仍保持SrAl2O4的晶体结构,其发光性能最好,发光强度最大,主激发波长在360nm左右,主发射波长在510nm左右;余辉为黄绿色,衰减时间长。

铕(III)三元活性配合物/丙烯酸凝胶的制备

以氧化铕(Eu2O3)、邻菲罗啉(phen)和丙烯酸(AA)为原料,制备了含铕(III)三元活性配合物Eu(AA)3phen,与丙烯酸-丙烯酰胺凝胶体系进行UV共聚,制备了含铕水凝胶。研究了凝胶中Eu(AA)3phen含量对其吸水性、温敏性及荧光性能的影响,同时探讨了温度及溶胀时间对其荧光性能的影响。结果表明,随Eu(AA)3phen含量的增加,凝胶吸水率先增加后减少,荧光强度逐渐增强;对于特定的凝胶体系,其12 h溶胀度随温度增加而增加,凝胶的荧光强度随溶胀时间和温度增加而减弱。当Eu(AA)3phen的添加量为3.5%时,凝胶综合性能最佳:平衡溶胀度为631 g/g,4 h内吸水率达90%以上,荧光强度为175 a.u.。所研制的水凝胶在吸水及荧光性能方面对温度均具有良好的响应性。

TiO_2-Li_2O-Nb_2O_5∶Eu^(3+)体系的研究

本文研究了 TiO_2-Li_2O-Nb_2O_5:Eu^(3+)体系中固溶体形成的温度与组成的关系。化学通式为 Ti_(1-4x-y)EuLixNb_3xO_2,当 y=0.2,0<x<1.04时,形成固溶体的温度为1156℃。结构为正交晶系。测定和讨论了 Eu^(3+)