锰掺杂对CaS：Eu光激励发光性能的影响

采用硫化助熔剂法制备了CaS：Eu，Mn荧光粉。通过测量样品的荧光光谱和紫外光辐照下的光激励发光谱，发现Mn离子的掺人使CaS：Eu的发光性能明显增强，存在于基质材料中的陷阱分布因掺人Mn杂质而改变，形成了新的俘获中心，引起能量转移。增大了电子俘获过程中电子和空穴复合的几率，有利于提高材料的存储性能。比较了不同浓度下发射光谱的差异，探讨了掺杂浓度对发光特性的影响。通过比较光激励发光衰减曲线，进一步表明了Mn掺杂对CaS：Eu光激励发光性能的改善。     

锰掺杂对CaS∶Eu光激励发光性能的影响

采用硫化助熔剂法制备了CaS∶Eu, Mn荧光粉.通过测量样品的荧光光谱和紫外光辐照下的光激励发光谱, 发现Mn离子的掺入使CaS:Eu的发光性能明显增强, 存在于基质材料中的陷阱分布因掺入Mn杂质而改变, 形成了新的俘获中心, 引起能量转移. 增大了电子俘获过程中电子和空穴复合的几率, 有利于提高材料的存储性能. 比较了不同浓度下发射光谱的差异, 探讨了掺杂浓度对发光特性的影响. 通过比较光激励发光衰减曲线, 进一步表明了Mn掺杂对CaS∶Eu光激励发光性能的改善.     

BaBrCl：Eu^2＋：一类新型X射线影像存储材料

在Eu^2＋掺杂的BaBrCl中，发现经X射线辐照后的光激励发光。BaClCl：Eu^2＋的发光峰位于413nm，两个差吸收带分别位于-550nm和675nm。激励光能量较BaFX：Eu^2＋（X=Cl，Br）低，与通常用作读出光源的HeNe激光器更为匹配。实验结果表明BaClCl：Eu^2＋有望成为一类新型的X射线影像存储材料。     

MO-RE2O3-B2O3(M=Mg,Ca,Sr,Ba;RE=La,Eu,Gd)玻璃的发光性质

在空气中采用高温固相反应方法合成的17MO－（8-x-y)-75B2O3-xGd2O3(MLBEG,M-Mg,Ca,Sr,Ba)玻璃，在紫外光（λex=350nm)激发下发射蓝光和红光，在绿色光（λex=532nm)激发下发射红光，电子自旋共振谱研究表明玻璃体系中有Eu^2 离子存在，蓝色区的宽带发射是Eu^2 离子的5d-4f跃迁发射：红色区的窄带发射是Eu^3 离子的5Do-7FJ(J=1,2,3,4)跃迁发射，发现玻璃中的碱土金属离子对Eu^3 /Eu^2 离子的比例有很大影响，选择不同的碱土金属离子可以调节玻璃蓝色光和红色光的相对发射强度，MLBEG玻璃的发光性质可用于转换太阳能，增强植物的光合作用。     

BaFCl：Sm晶体的光激励发光和热释发光

研究了在X射线辐照及光激励发光和热释发光过程中,BaFCl:Sm晶体中钐离子的价态变化和F色心的产生和湮灭过程。提出了如下的BaFCl:sm晶体的光激励发光和热释发光过程:在X射线辐照下,晶体中产生F色心,同时一部分Sm~(3 )俘获空穴形成Sm~(4 ),还有少量的Sm~(3 )得到电子形成Sm~(2 )。在光激励发光和热释发光过程中,从F色心中电离出来的电子与Sm~(4 )复合转变成Sm~(3 )激发态,随后发出Sm~(3 )的特征光辐射。同时在热释发光中,Sm~(2 )还可以与空穴复合,转变成Sm~(3 )的激发态,也发出Sm~(3 )的光辐射。     

利用热释光和光激励技术研究合成工艺对BaFBr：Eu^2＋,Al^3＋发光性质的影响

利用热释发光谱和光激励发光谱表征了不同合成工艺条件对合成BaFBr:Eu^2 ,Al^3 发光性质的影响，利用理论分析找出了热释发光衰减与光激励衰减的异同，理论上计算了不同的合成工艺对BaFBr:Eu^2 ,Al^3 色心能级的影响，其热释发光谱和光激励发光谱的理论计算值能较好的吻合，并且能够很好的表征实验结果。     

Pr3+掺杂的LaF3纳米微晶/氟氧化物玻璃陶瓷的激光选择激发

研究了Pr^3 掺杂纳米晶／氟氧化物玻璃陶瓷的光谱性质，选择激发光谱分辨了氟氧化物玻璃陶瓷和其中的LaF3纳米微晶内的Pr^3 离了，可以看到LaF3纳米微晶／氟氧化物玻璃陶瓷体系在光谱上未表现出明显的界面效应，这对良好的发光性质可能是一种有利因素，纳光微粒小的尺寸和大表面增加了掺杂离子的局域环境的离散性，使纳米微粒中谱线的非均匀线宽比体材料中大，且随粒径减小而增加，掺杂离子在微晶中富集，或在界面附近富集，提高了微晶中或微晶内局部范围中的浓度，增加了交叉迟豫的几率，出现浓度猝灭，因此Pr^3 离子在LaF3中的富集而引起的浓度猝灭是发光能级寿命缩短的主要原因。     

CaBPO5：RE（RE=Eu，Tb）的水热合成及其发光特性

利用水热法合成了CaBPO5：RE(RE=Eu，Tb)荧光体并测试了其结构和光谱，讨论了其发光性质，并与高温固相法合成的产物作了对比．结果表明，由于电子转移。Eu^3 ,Tb^3 和Eu^2 共存于同一体系中，而且Eu^2 的发射位置从402nm移至428nm,在双掺杂体系中引入Ce^3 ．Eu^3 ，Tb^3 和Eu^2 的发光强度均有所增强,这可能是Ce^3 与Eu^3 之间的电子转移及各种稀土离子之间能量传递相互竞争的结果。     

Ho3+/Yb3+共掺ZnO-Al2O3-GeO2-SiO2玻璃陶瓷的制备和上转换发光性质

综合ZnO-Al_2O_3-SiO_2系和锗酸盐玻璃陶瓷的优点,采用熔融-晶化法首次制备了Ho~(3+)/Yb~(3+)共掺以ZnAl_2O_4为主晶相的ZnO-Al_2O_3-GeO_2-SiO_2系玻璃陶瓷。因[GeO_4]四面体和[SiO_4]四面体都是玻璃网络形成体,讨论了GeO_2取代SiO_2对玻璃陶瓷样品硬度及发光性能的影响,最终确定GeO_2的取代量为10.55%(w/w)时,玻璃陶瓷综合性能最佳。在980 nm泵浦光的激发下,发现强的绿色(546 nm)和弱的红色(650 nm)上转换发光,并研究了不同Ho~(3+)/Yb~(3+)掺杂比对样品上转换发光的影响,最终结果表明当Ho~(3+)/Yb~(3+)掺杂比为1∶11(n/n)时样品荧光强度最强,在绿色上转换发光材料方面具有潜在的应用。     

超声化学法制备BaF_2纳米粒子及纳米方块

<正>0引言BaF2的用途非常广泛,可用于光学玻璃、陶瓷色料、玻璃光导纤维、激光发生器、助熔剂及防腐剂等。BaF2是最快的闪烁体,在核物理和核技术中用来检测γ射线和带电粒子[1]。将掺杂稀土金属的纳米BaF2粒子嵌入有机或玻璃基体以发挥其发光性能的研究越来越引起重视[2]。碱土氟化物和许多半导体的晶格匹配性良好,可以用不同碱土氟化物层来连接晶格常数不同的半导体[3]。     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.