稀土铕高分子荧光配合物的制备及性能研究

稀土配合物作为发光材料已广泛应用于众多领域,为了使材料获得更稳定更持久的发光性能,本文以N-乙烯基甲酰胺(NVF)和丙烯酰胺(AM)为共聚单体,水为溶剂,在高温、引发剂条件下经自由基溶液聚合制备出含有氨基、羧基等多种配位官能团的水溶性高分子聚合物两性聚乙烯胺(PVAm),并以此作为高分子配体,再辅以1,10-邻菲咯啉(phen)作为第二配体,用三价稀土离子铕(Eu)的盐溶液与之配位,制备出具有优良荧光效应的稀土配合物Eu(PVAm)_3phen荧光粉。对高分子配体PVAm进行IR、NMR等分析,找出配位官能团,并对稀土配合物的外观形貌进行荧光显微镜等观察分析,对配合物的结构进行XRD等表征,并分析其紫外光谱、荧光光谱、荧光余辉亮度。配合物在220～275 nm范围内对紫外光有较强的吸收,最大吸收峰在260 nm处。配合物在580、593、614、650 nm的4处有明显的荧光发射峰。     

ATOCA调控下的聚苯乙烯的合成及端基配位

在过氧化二苯甲酰(BPO)的引发下,以4-氨基-4-羧基-2,2,6,6-四甲基哌啶氧(ATOCA)为调控剂,成功进行了苯乙烯的氮氧稳定自由基本体聚合。结果表明聚合是可控的。根据氮氧稳定自由基聚合(NMP)的聚合机理,利用在聚合物末端封端的ATOCA上的羧基进行稀土金属铕(Eu(Ⅲ))的配位,获得了具有荧光性的聚合物。通过对配合物的激发光谱和荧光光谱分析,证明了稀土金属配位发生在聚合物链的末端,而非简单的物理掺杂。     

聚/N-异丙基丙烯酰胺-铕-噻吩甲酰三氟丙酮的光谱性质及能量传递的研究

首次合成了铕-聚(N-异丙基丙烯酰胺)-噻吩甲酰三氟丙酮(Eu3+-PNIPAM-TTA)三元配合物,并用紫外光谱、红外光谱和荧光光谱进行了初步表征.结果表明,Eu3+与PNIPAM侧链中氮原子或氧原子配位,Eu3+-PNIPAM-TTA体系为三元配合物,而并非PNIPAM与铕-噻吩甲酰三氟丙酮(Eu3+-TTA)的混合物;Eu3+-PNIPAM-TTA三元配合物的614 nm波长荧光强度比Eu3+-PNIPAM及Eu3+-TTA二元配合物分别增强了20900%和183%,在能量传递中,高分子以F(o)rster能量传递方式将紫外激发能传递给TTA,再经TTA传递给Eu3+,而获得增强的Eu3+的特征发射.并考察了不同合成条件下的荧光光谱性质.     

铕铽配合物/甲基丙烯酸酯型聚合物复合材料的制备及表征

采用原位合成法制备了一系列不同铕铽比例的稀土配合物/甲基丙烯酸酯型聚合物复合材料.利用红外光谱、SEM图像、紫外-可见吸收光谱和光致发光光谱表征了材料的结构、微观形貌、光学带隙及发光性能.结果表明,铕铽稀土配合物/甲基丙烯酸酯型聚合物复合材料在365nm紫外光激发下,均能产生发光峰在613nm附近的红光发射,发光亮度高,色纯度高,且发光强度与共聚物中MAA的含量有关;Tb3+对Eu3+荧光性能的影响与Tb3+所占比例有关,即当Tb3+比例较小时,对Eu3+产生荧光猝灭作用,当Tb3+比例较大时,对Eu3+产生荧光敏化作用.     

红色荧光粉Ba_(4-4x)B_(11)O_(20)F∶4xEu~(3+)的制备及发光性能

以BaCO_3、BaF_2、H_3BO_3和氧化铕(Eu_2O_3)原料,采用高温固相反应法制备了一系列新型荧光材料Ba_(4-4x) B_(11)O_(20)F∶4xEu~(3+)(x=0.06、0.08、0.10、0.12、0.14)。利用XRD、SEM和荧光分光光度计对粉体结构、形貌和发光性能进行表征,并研究了铕离子(Eu~(3+))掺杂量对Ba_(4-4x)B_(11)O_(20)F∶4xEu~(3+)发光性能的影响。研究结果表明在激发波长为465nm的条件下,材料的发射峰主要位于592、598、616、654和700nm处;随着Eu~(3+)离子浓度的增大,样品的发光强度先增大后减小,最佳掺杂浓度为x=0.12。     

GO改性铕(Ⅲ)-二苯甲酰甲烷-三苯基氧膦及其发光性能研究

采用超声辅助溶剂热法合成一种氧化石墨烯(GO)改性铕(Ⅲ)-二苯甲酰甲烷-三苯基氧膦(Eu-DBMTPPO-GOs)近紫外转换红光材料,通过元素分析、紫外光谱、红外光谱、热重、X射线粉末衍射、扫描电镜和荧光对结构和性能进行表征。结果表明:配体与铕原子有效配位,适量GO添加改性能提高材料发光性能和品质。添加质量为0.009%时,分解温度达到230℃以上,在300~500nm呈现强激发带,在611nm发射强特征红光,量子产率23.5%,荧光寿命0.212ms,色坐标(0.655,0.340),并结合结构和性能对GO改性机理进行了分析。     

镧掺杂铕的2,5-噻吩二羧酸-1,10-菲咯啉四元异核配合物的合成、表征及谱学性质

合成了5种新型镧掺杂铕的2,5-噻吩二羧酸(H2L)、1,10-菲咯啉(Phen)四元异核配合物,通过元素分析、TG-DTA、红外光谱法确定其组成为(EuxLay)2L3(Phen)2·4H2O(x∶y=0.90∶0.10、0.70∶0.30、0.50∶0.50、0.30∶0.70、0.10∶0.90),配体的羧基与稀土离子以螯合双齿配位。荧光光谱测试表明镧对铕的配合物有荧光浓聚效应。     

一种新型罗丹明席夫碱(RHBS)制备及多功能性研究

以罗丹明B酰肼、3-溴水杨醛为原料,通过活性氨基与醛基的缩合反应,制备了一种新型罗丹明B席夫碱化合物(RHBS)。该化合物作为配体与锌离子配位,可得到新的红光发光材料[RHBS-Zn(Ⅱ)];作为荧光探针,可实现锌离子高灵敏选择性。通过核磁共振氢谱、红外光谱、紫外光谱、荧光光谱对席夫碱配体RHBS及配合物[RHBS-Zn(Ⅱ)]进行了结构和性能的分析。结果分析表明:锌离子以1∶1的方式与配体RHBS上亚氨基的N原子、羰基中的O原子及酚基中的O原子配位,形成锌离子配合物[RHBS-Zn(Ⅱ)]。在556 nm光的激发下,配合物在587 nm处有明显的特征红色荧光产生,且配合物的发光荧光量子产率达15.1%。同时,在587 nm处,不受其它离子干扰,对Zn(Ⅱ)具有高的荧光探针选择性,是Zn(Ⅱ)很好的荧光探针检测材料。     

基于TNT敏感聚合物的纳米阵列结构的制备与性质

利用多孔氧化铝模板法制备了两种1,3,5-trinitrotoluene(TNT)敏感的荧光共轭聚合物Tri-phenylamine-CO-para-biphenyene vinylene(TPA-PBPV)和Triphenylamine-co-para-phenyl-ene vinylene(TPA-PPV)的纳米线阵列结构.纳米线的直径在80～100 nm之间,高度在150-200nm之间.和固体薄膜相比,TPA-PBPV和TPA-PPV荧光光谱都发生了蓝移,TPA-PBPV的发射峰从485变为455 nm,PPV的峰从495 nm变为475 nm.蓝移的发光表明聚合物纳米线阵列可以抑制低能量陷阱,有望提高材料的传感性能.     

静电纺丝技术制备PAN/Eu(BA)3 phen复合发光纳米纤维与表征

采用静电纺丝技术制备出聚丙烯腈(PAN)/Eu(BA)3phen复合纳米纤维;采用扫描电子显微镜(SEM)对其结构进行了表征,复合纳米纤维表面光滑,平均直径在400～720nm.荧光光谱和荧光寿命分析表明,复合发光纳米纤维均能发出强的铕离子的特征荧光,具有较高发光效率和色纯度高,且荧光寿命高于稀土配合物.     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.     

空压机轴承箱蜗壳温度探头油封改造

由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。     

Characteristics of mechanical properties of materials in studies of conditions of attainment of marginal states

It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle.     

Determination of parameters of microstructural inhomogeneity of deformation of metals by the method of modeling

The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

水三相点复现的不确定度评定

水三相点是开尔文热力学温度的唯一基准点，也是ITS-90国际温标重要的定义固定点。因此，水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来，中国计量科学研究院研制出一系列高质量的水三相点容器，加强了水三相点的研究，为不确定度的分析提供了更为可靠的实验依据。同时，不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此，根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明，其扩展不确定度为0．16mK(k=2．69，P=0．99)。