Tm:K2YF5晶体的光谱参量计算

测量了Tm:K2YF5晶体的吸收光谱,根据Judd-Ofelt理论计算了Tm3+在K2YF5中的强度参数:Ω2=5.02×10-20cm2,Ω4=3.40×10-20cm2,Ω6=0.38×10-20cm2,以及Tm3+激发能级的自发辐射跃迁几率A,荧光分支比β,荧光寿命τ和积分发射截面∑等光谱参量.     

Tm3+掺杂的新型铋酸盐玻璃的制备与光谱特性

通过传统熔融法,分别制备了Tm3+单掺和Tm3+/Yb3+共掺的新型铋酸盐玻璃Li2O-SrO-ZnO-Bi2O3(LSZB),采用拉曼光谱、吸收光谱、荧光光谱对其进行了表征.应用Judd-Ofelt理论,计算了Judd-Ofelt参数Ωt(t=2,4,6),分别为Ω2=4.29×10-20 cm2,Ω4 =1.16×...     

新型掺铒铋酸盐玻璃上转换发光研究

制备了新型掺Er3 铋铅锶玻璃,研究了玻璃的吸收光谱和上转换光谱性质,应用Judd-Ofelt理论计算了铋铅锶玻璃的3个强度参量Ωt(t=2,4,6),分别为Ω2=3.27×10-20 cm2,Ω4=1.15×10-20cm2,Ω6=0.38×10-20 cm2.计算了Er3 离子的振子强度、自发辐射跃迁几率、荧光分支比和辐射寿命等光谱参数.研究了上转换发光强度随泵浦激光功率的变化,上转换荧光525,546和657 nm曲线的斜率分别为1.86,1.88和1.85,表明红、绿光发射均为双光子吸收过程.     

掺铒TeO2-WO3玻璃光谱性能

研究了掺铒TeO2-WO3玻璃的吸收光谱和荧光光谱性质.根据吸收光谱,应用Judd-Ofelt理论计算得到了3个强度参数Ωt(t=2,4,6),分别为Ω2=5.38×10-20cm2,Ω4=1.78×10-20 cm2,Ω6=0.75×10-20cm2.Er3 离子在TeO2-WO3玻璃中的Ω6小于磷酸盐、氟磷酸盐中的Ω6,而大于锗酸盐、硅酸盐和碲酸盐玻璃中的Ω6,说明Er-O键在TeO2-WO3玻璃中的共价性大于磷酸盐、氟磷酸盐中Er-O键的共价性而小于锗酸盐、硅酸盐和碲酸盐玻璃中Er-O键的共价性.4I13/2→4I15/2荧光光谱表明Er3 的荧光半高宽(FWHM)为66 nm,荧光寿命为3.2 ms;应用McCumber理论计算了Er3 的峰值发射截面σe为8.0×10-21cm2.对Er3 在不同基质玻璃中光谱参数比较发现,TeO2-WO3玻璃的FWHM×σe乘积较大,说明其带宽特性较好.     

Yb3+敏化宽波带掺Er3+氟磷酸盐玻璃的发光性质及Judd-Ofelt理论研究

采用高温熔融法制备了一种新的Er3+/Yb3+共掺氟磷酸盐玻璃,测试和分析了其密度、吸收光谱以及荧光光谱,讨论了Er3+离子和Yb3+离子对光谱性质的影响.根据Judd-Ofelt理论计算了玻璃中Er3+离子的强度参数Ωt(t=2,4,6),分别为Ω2=4.36×10-20cm2,Ω4=1.35×10-20cm2,Ω6=0.79×10-20cm2,以及Er3+离子4I13/2能级荧光寿命τm=8.26ms.主发射峰1.53μm处半高宽(FWHM)为68nm.根据McCumber理论计算了Er3+的受激发射截面σe=8.5×10-21cm2.比较了不同玻璃基质中Er3+离子的光谱特性,结果表明:Er3+/Yb3+双掺氟磷酸盐玻璃在1.53μm附近具有较宽的半高宽和较大的受激发射截面,是一种高增益掺铒光纤放大器的理想介质材料.     

ZBLAN玻璃中三价铒离子 2H11/2,4S3/2辐射跃迁的量子效率

为了探讨铒离子掺杂材料的激光制冷可能性, 依据测量样品的吸收光谱, 计算了Er3 掺杂的ZBLAN玻璃材料的Judd-Ofelt参数, 得到Ω2=3.01×10-20 cm2, Ω4=1.59×10-20 cm2, Ω6=1.03×10-20 cm2, 进而获得了2H11/2, 4S3/2及其以下各能级间跃迁的跃迁几率、分支比、寿命等数据. 测量了77 K到315 K温度范围内Er3 较强的两个绿色发射2H11/2, 4S3/2→4I15/2的发射谱及荧光寿命. 讨论了2H11/2, 4S3/2这样处于热平衡中的两个能级的量子效率的计算方法, 进而计算了它们的量子效率, 并与其它材料进行了比较.     

新型激光晶体α—Nd：Ba3Y（BO3）3光谱性能研究

研究了高温相掺钕硼酸钇钡α Nd∶Ba3Y(BO3)3(α NBYB)晶体的光谱特性。α NBYB晶体具有R3空间群结构。吸收光谱表明:该晶体在808nm左右有比较强的吸收峰,其对应于4I9 2→4F5 2,2H9 2的能级跃迁,半峰宽(FWHM)15nm,相应的吸收截面为1.56×10-20cm2,荧光光谱表明:4F3 2→4I11 2能级跃迁有很强的荧光发射,其发射波长为1.058μm,相应的荧光寿命为70μs,发射跃迁截面为1.82×10-19cm2,并用J O理论计算了该晶体的振子强度参数:Ω2=1.43×10-20,Ω4=2.08×10-20,Ω6=2.45×10-20cm2。     

Tm，Ho∶BaY2F8晶体光谱性能与能量传递

采用提拉法,生长钬铥双掺氟化钇钡[分子式:Tm3+,Ho3+∶BaY2F8,简称Tm,Ho∶BYF]激光晶体。工艺参数:拉速0.5 mm.h-1,转速5 r.min-1,冷却速率10℃.h-1。XRD表明:属于单斜晶系,空间群C12/m1。计算出晶格参数:a=0.69973 nm,b=1.05293 nm,c=0.427 84 nm,β=99.71°。测试了晶体的吸收及荧光光谱,同时计算了784 nm处吸收峰的半高宽、吸收系数及吸收截面,分别为3.2 nm,2.23 cm-1,7.44×10-21 cm2。该吸收峰对应于Tm3+离子从基态3H6到激发态3H4的跃迁。Tm,Ho∶BYF晶体在2.06μm附近有很强的荧光发射峰,在该荧光峰的发射截面和荧光寿命分别为4.96×10-21 cm2,10.1 ms。Tm3+→Ho3+的正向、反向能量转换系数之比是10.4。     

Er~(3+)铋铅锶玻璃吸收光谱和上转换光谱

制备了新型掺Er3+铋铅锶玻璃,研究了玻璃的吸收光谱和上转换光谱性质,应用Judd-Ofelt理论计算了铋铅锶玻璃的3个强度参量Ωt(t=2,4,6),分别为Ω2=3·27×10-20cm2,Ω4=1.15×10-20cm2,Ω6=0.38×10-20cm2。计算了Er3+离子的振子强度、自发辐射跃迁几率、荧光分支比和辐射寿命等光谱参数。研究了上转换发光强度随泵浦激光功率的变化,上转换荧光525,546和657nm曲线的斜率分别为1·86,1·88和1·85,表明红、绿光发射均为双光子吸收过程。     

钠快离子导体Na1+xZr2-yTiySixP3-xO12系统研究(Ⅰ)

以Na_3PO_4、ZrP_2O_7、SiO_2、ZrO_2、TiO_2为反应原料,在1173K—1473K的高温下进行固相反应,制备了钠快离子导体Na_(1 x)Zr_(2-y)Ti_ySi_xP_(3-x)O_(12)系统中x=1、y=0—2.0的一系列合成物。研究了它们的相变关系;测定了两个单纯相—211相和202相的电导率和电导激活能。 室温时,211相的电导率σ_(RT)=1.52×10~(-4)(Ω·cm)~(-1),202相的σ_(TR)=0.53×10~(-4)(Ω·cm)~(-1);623K时,211相的电导率σ_(623)=1.21×10~(-1)(Ω·cm)~(-1),202相的σ_(623)=0.88×10~(-2)(Ω·cm)~(-1)。 在523K～673K温区里,211相的电导激活能E_a为31.87kJ/mole,202相的E_a为33.16kJ/mole。     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

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。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

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.