YIG及Bi—YIG薄膜材料的光吸收谱的微观机理研究

采用ＤＶ－Ｘα方法计算了ＹＩＧ薄膜的电子结构，在能态密度的基础上，得出了导致光吸收的两种电荷转移跃迁。在１２￣２０ｃｍ＾－１×１０＾３波长范围，计算出了与实验一致的吸收谱。Ｂｉ＾３＋离子的掺入，增大了跃迁的振子强度，其增大量与铋离子的浓度成正比。在此基础上得出的Ｂｉ－ＹＩＧ的理论谱与实验谱符合得较好。     

掺铋钇铁石榴石光吸收谱的理论计算

利用ＤＶ－Ｘα方法分别计算了Ｆｅ＾３＋Ｏ＾２－６和Ｆｅ＾３＋Ｏ＾２－４原子族的能态密度和能级，在能级图的基础上，给出了０．５－０．９μｍ（１．６ｅｒ－２．３ｅｖ）范围内Ｂｉ－ＹＩＧ与吸收有关的跃迁能级，振子强度和跃迁线宽，并计算了相应的吸收谱，理论计算与实验结果符合较好。     

掺Ce稀土铁石榴石单晶的制备及磁光性能

采用改进的助熔刑法生长块状Ｃｅ：ＹＩＧ单晶,分析了它的晶体结构、测试了在近红外波段的磁光性能Ｃｅ~３＋掺入铁石榴石十二面体位极大地增强了材料的法拉第旋转,在λ＝０．７８μｍ时,Ｙ３Ｆｅ５Ｏ１２晶体中每一个 Ｃｅ~３＋替代 Ｙ~３＋;其Ｆ的增加量（ｄθＦ,／ｄｘ）达到 ０．６×１０~４ｄｅｇ／ｃｍ,比同量 Ｂｉ~３＋替代时晶体Ｆ的增加量高２倍,在稀土铁石榴石中掺入Ｙｂ和Ｅｕ;由于其有弱的还原性,能抑制Ｃｅ~４的形成,增加 Ｃｅ~（３＋）离子的替代量。     

YIG及Bi－YIG薄膜材料的光吸收谱的微观机理研究

采用ＤＶ－Ｘα方法计算了ＹＩＧ薄膜的电子结构，在能态密度的基础上，得出了导致光吸收的两种电荷转移跃迁。在１２～２０ｃｍ－１×１０３波长范围，计算出了与实验一致的吸收谱。Ｂｉ３＋离子的掺入，增大了跃迁的振子强度，其增大量与铋离子的浓度成正比。在此基础上得出的Ｂｉ－ＹＩＧ的理论谱与实验谱符合得较好。     

用于光纤电流传感器的BiGd：YIG和Gd：YIG激光单晶的生长及性能 …

本文用助溶剂熔盐法生长了具有高法拉第旋转角,低温度灵敏性的磁光石榴石单晶：（ＹＢｉＧｄ）３Ｆｅ５Ｏ１２（ＢｉＧｄ：ＹＩＧ）和（ＹＧｄ）３Ｆｅ５Ｏ１２（Ｇｄ：ＹＩＧ）。     

（BiAl）YIG薄膜的生长感生磁各向异性

从理论和实验上分析了Ｆｅ＾３＋和Ｆｅ＾２＋对（ＢｉＡ）ＹＩＧ薄膜的生长感各向异性的贡献，掺Ｂｉ导致的生长磁感生各向异性，来源于Ｅｉ＾３＋改变了Ｆｅ＾３＋的零场劈裂，其大小取决于Ｂｉ＾３＋含量及在十二面体位的择优分布，高价离子和氧空位形成的Ｆｅ＾２＋在八面体位的择优分布，对生长感生磁各向异性也有贡献。     

真熔紫外光激发下Tb^3＋激活的稀土正硼酸盐的发光

报导了Ｔｂ＾３＋，Ｃｅ＾３＋激活的土正硼酸盐的真空紫外光谱。分析了Ｃｅ＾３＋的４ｆ＾７５ｄ能级随基质结构，基质阳离子的变化，讨论了温度，Ｔｂ＾３＋离子的浓度对发光的影响以及Ｃｅ＾３＋－Ｔｂ＾３＋间的能量传递。     

钇铁石榴石薄膜材料的光吸收谱及Bi,Al掺入对谱的影响研究

采用单离子晶场跃迁模型，拟合出钇铁石榴石（ＹＩＧ）薄膜材料的光吸收谱，与实验谱吻合得较好。从实验和理论上分析了（ＢＩＡＩ）ＹＩＧ 薄膜材料的光吸收谱，结果表明，Ａｌ３＋离子的作用如同稀释剂一样，减小了光吸收，Ｂｉ３＋离子由于其强的自旋轨道耦合作用，增大了跃迁振子强度和跃迁线宽，从而增大了光吸收损耗，在此基础上所作的（ＢｉＡｌ）ＹＩＧ的理论谱与实验谱符合得较好。     

用于光纤电流传感器的BiGd∶YIG和Gd∶YIG磁光单晶的生长及性能研究

本文用助溶剂熔盐法生长了具有高法拉第旋转角、低温度灵敏性的磁光石榴石单晶：（ＹＢｉＧｄ）３Ｆｅ５Ｏ１２（ＢｉＧｄ∶ＹＩＧ）和（ＹＧｄ）３Ｆｅ５Ｏ１２（Ｇｄ∶ＹＩＧ）。对所生长的单晶,经Ｘ射线和扫描电镜能谱测试,分析了结构和晶体组成。测试光吸收系数和比法拉第旋转角等磁光性能,并用分子场理论分析了晶体的饱和磁化场和法拉第旋转角随温度变化的关系。结果表明ＢｉＧｄ∶ＹＩＧ非常适合光纤电流传感系统等一些磁光器件的应用     

Al^3＋和Mn^2＋对YGdCaVInIG性能的影响

本文对少含稀土氧化物的ＹＧｄＣａＶＩｎＩＧ材料的性能和结构进行了分析研究，重点讨论了用Ａｌ＾３＋和Ｍｎ＾２＋替代Ｆｅ＾３＋对铁氧体性能的影响。     

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.     

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.     

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.     

可燃气体检测报警器测量结果的不确定度评定

本文详细介绍了可燃气体检测报警器示值误差测量结果的不确定度评定方法。     

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)。     

心电图机电压测量示值误差测量值的不确定度评定

本文介绍了心电图机电压测量示值误差测量值的不确定度评定与表示方法。     

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.