孔雀石和蓝铜矿的局域结构和吸收光谱的研究

在晶体场理论的基础上,采用半自洽场(Semi-SCF)自由Cu2+的d轨道模型和点电荷模型,建立了过渡金属离子矿物晶体的局域结构和吸收光谱之间的定量关系,统一的解释了孔雀石和蓝铜矿的局域结构和Cu2+的不同占位时的吸收光谱,所得理论计算结果与实验值一致,同时在理论上预测了它们的顺磁g因子,这为进一步研究孔雀石和蓝铜矿的结构、光学、磁学、热学及高压等性质提供了理论依据.     

Zn3V2O8的电子结构与光学性质的理论研究

采用平面波超软赝势密度泛函理论的方法研究了Zn3V2O8的能带结构、电子态密度和光学特性.能带结果显示Zn3V2O8呈间接带隙的绝缘体型能带,其禁带宽度为2.9 eV.详细的电子态密度结果显示其费米面上的态密度达到20 e/eV,费米能级附近的能级由Zn3p、V3p和O2p电子形成,Zn3d和O2s之间有强的杂化作用.介电性能结果显示在4.4 ～5.7 eV附近有强的吸收峰,在20.6 eV附近有一个次强吸收峰;吸收光谱显示在6.8 eV处有强吸收,在20.7 eV处有一个较弱的吸收峰.     

Al2O3-C材料中Ti(C,N)的形成及其抗气化炉渣侵蚀性能研究

水煤浆气化炉内衬材料的无铬化势在必行.基于碳氮化钛对高炉渣的增稠机理,本工作在前期开发水煤浆气化炉用Al2O3-C无铬化内衬材料的基础上,拟通过在Al2O3-C材料中引入一定量的TiO2,使之在高温下材料内原位反应形成碳氮化钛相,提高材料的抗气化炉渣侵蚀性能.结果表明:当Al2O3-C材料引入适量的TiO2时,可以发现在烧成过程中材料中原位形成了Ti(C,N)相,优化材料的孔结构;当材料与渣发生反应时,提高了在侵蚀过程中渣的粘度,改善材料的抗侵蚀性能.当材料中引入的过量的TiO2,TiO2易与气化炉渣发生反应,降低渣的粘度,从而降低材料的抗侵蚀性能.     

铜锌掺杂的六铝酸盐分解N2O催化性能研究

采用共沉淀法制备了Cu和Zn取代六铝酸盐（LaCu_xZn_1-xAl₁₁O_19-δ,x=0、0.2、0.4、0.5、0.6、0.8、1.0）催化剂,通过XRD和BET等技术对催化剂进行表征,利用微型固定床反应器考察催化剂对N₂O的分解活性。结果表明,以(NH₄)₂CO₃为沉淀剂制备的催化剂在1 200 ℃焙烧4 h,可以形成完整的六铝酸盐晶型,Cu和Zn能够取代Al³⁺进入六铝酸盐晶体结构。LaCu_xZn_1-xAl₁₁O_19-δ催化剂对N₂O分解有较好的催化活性,其中,LaCu_0.8Zn_0.2Al₁₁O_19-δ活性较好。在LaCu_xZn_1-xAl₁₁O_19-δ六铝酸盐中,Cu为N₂O催化分解的主要活性元素,Zn有助于提高催化剂的稳定性,但由于六铝酸盐的特殊结构,Zn在催化剂中的作用较小。     

Enhance the luminescence properties of Ca14Al10Zn6O35:Ti4+ phosphor via cation vacancies engineering of Ca2+ and Zn2+

Ti⁴⁺-activated zinc calcium aluminate phosphors, owing to their excellent luminescence properties, nontoxicity, environment friendliness and low price, have a certain prospect in the field of plant cultivation. In this study, we have successfully synthesized a series of Ca_14-yAl_10-xZn_6-zO₃₅:xTi⁴⁺ (CAZO:Ti⁴⁺) phosphors through a high-temperature solid-state method. Furthermore, the emission spectrum of CAZO:Ti⁴⁺ located in bluish violet-emitting band, and has an emission peak at 378?nm upon the excitation of 268?nm due to the charge transfer of Ti⁴⁺-O^2-. Moreover, the luminescence intensity of as-synthetized phosphors can be improved by cation vacancies engineering to compensate for charge unbalance. Especially, the luminescence intensity could be further improved when the Ca²⁺ vacancy is 0.35?mol or the Zn²⁺ vacancy is 0.275?mol. Furthermore, the X-ray powder diffraction (XRD) analysis and crystal structure are checked and confirmed that the synthesized material is pure phase. The concentration quenching mechanism, FT-IR spectra, UV–vis absorption properties, lifetimes and electron transition process of Ca_14-yAl_10-xZn_6-zO₃₅: xTi⁴⁺ were discussed in detail. From the above, the phosphor has a potential application for plant growth field due to its broad bluish violet emission.     

Effect of Gamma Radiation on Optical and EPR Absorption Spectra of Phosphate and Fluoride Glasses Containing Lead

The induced optical and EPR absorption spectra of phosphate and fluoride glasses containing lead are investigated. It is revealed that exposure to gamma radiation leads to the formation of radiation-induced defects responsible for the induced absorption band with a maximum at 12500–13500 cm⁻¹ and the EPR signal in the form of an almost symmetric line with a g factor of 1.999 and a linewidth of ≈26 Oe. Analysis of the intensities of the absorption bands and the EPR signals in the spectra of glasses with low terbium, tin, and carbon contents and the study of their thermal bleaching demonstrate that the color centers are electron traps, whereas the paramagnetic centers are hole-trapping centers. Examination of the change in the parameters of the absorption bands in the spectra of glasses with different R ₂O contents (R = Na, K, Rb, Cs) makes it possible to determine the location of the color centers associated with the Pb⁺ ions in the structure. It is established that the glasses under investigation are characterized by the nonlinear absorption of radiation at a wavelength of 1.06 μm. The mechanism of formation of radiation-induced defects is considered. Original Russian Text Copyright ? 2005 by Fizika i Khimiya Stekla, Bocharova, Karapetyan.     

蛭石处理含Cu^2＋和Zn^2＋废水的性能研究

从吸附时间、蛭石用量和溶液pH三方面研究了蛭石对Cu^2＋和Zn^2＋两种重金属离子的吸附性能。结果表明,蛭石对这两种重金属离子均有较好的吸附作用。蛭石对Cu^2＋和Zn^2＋的吸附量随吸附时间的增加而增大,当吸附时间达到60min时,蛭石对Cu^2＋和Zn^2＋的吸附量分别为4.94mg·g^-1和4.97mg·g^-1。在相同蛭石用量和相同溶液浓度的条件下,蛭石对Cu^2＋的吸附效率略高于Zn^2＋。pH是影响吸附量的主要因素,吸附量随着pH的升高而增大。     

一种新型铜配合物Cu_2(C_6H_8O_4)_2(C_3H_7NO)_2的合成和晶体结构

本文以苯并咪唑-5-羧酸、己二酸、硫酸铜为原料,以水/DMF(v/v 1:1)为溶剂,采用水热合成法合成了新型铜配合物Cu_2(C_6H_8O_4)_2(C_3H_7NO)_2单晶,并通过单晶衍射仪测定了晶体结构。该配合物属于为单斜晶系,空间群为P21/n,晶胞参数为:a=9.4764(5)?,b=8.2618(5)?,c=15.0990(8)?,β=106.259(1)o,V=1134.85(11)?3,Z=2。     

Manipulation of the ratio of Li+/Zn2+ on the structure and persistent luminescence property of Li2Zn0.9992Ge3O8:0.08%Cr3+

Long persistent luminescence (LPL) materials have been widely applied and investigated in the fields of night-safe, bio-fluorescent labeling, and optical anti-counterfeiting because of their unique properties of delayed luminescence. In this work, the focus of this research is to significantly improve the LPL properties of Li₂Zn_0.9992Ge₃O₈:0.08%Cr³⁺ by adjusting the ratio of Li⁺/Zn²⁺. On the one hand, when Li⁺:Zn²⁺ < 2:1 (Li_1.97Zn_1.0292Ge₃O₈:0.08%Cr³⁺), a deep-red LPL is produced in the 650–900 nm band for more than 50 h, which is 2.5 times longer than that without regulation. From another perspective, when Li⁺:Zn²⁺ > 2:1 (Li_2.01Zn_0.9892Ge₃O₈:0.08%Cr³⁺), the intensity of LPL is enhanced about four times compared to unregulated. The relationship between traps and LPL was comprehensively investigated by analyzing thermoluminescence spectra. Biological tissue penetration experiments were performed and a set of anti-counterfeit labels was designed. This research will provide guidance for the design of a novel persistent phosphor for the desired trap depth.