Br^—2,Cl^—2.诱导氧化磷酰化甲硫氨酸水溶液的脉冲辐解研究

采用脉冲辐解动态吸收光谱法研究了Ｂｒ＾－２和Ｃｌ＾－２自由在诱导氧化Ｎ－二异丙基磷酰化甲硫氨酸（ＮＤＭ）水溶液的过程，结果表明：Ｂｒ＾－２和Ｃｌ＾－２进攻ＮＤＭ中的硫原子形成含硫三电子键ＮＤＭ（Ｓ∴Ｘ）（Ｘ＝Ｂｒ，Ｃｌ）它们分别在４００ｎｍ和３９０ｎｍ处有最大吸收峰，形成和衰变均呈一级反应，测定了不同条件下氧化反应的速率常数，推导了反应机理，并从分子结构观点与甲硫氨酸水溶液的Ｂｒ＾－２．Ｃｌ＾－２     

一种可用于分析任意介电常数张量的各向异性波导导模的二维时域有限差分模型

为分析具有任意介电常数张量的各向异性波导的导模，本文通过把简化的二维时域有限差分（２－ＤＦＤＴＤ）法扩展至任意各向异性介质，提出了一种以Ｄ、Ｅ和Ｈ场为基础的统一的简化２－ＤＦＤＴＤ模型．利用该模型，研究了简化的复数２－ＤＦＤＴＤ方法与实变数２－ＤＦＤＴＤ方法之间的关系．文中还讨论了复变数方法和实变数方法的激励技术．     

BaFCl_（x）Br_（1－x）：Sm~（2＋）中_（5）D_2→~（7）F_

本文以ＢａＦＣｌｘＢｒ－１－ｘ：Ｓｍ２＋Ｄ２→７Ｆ０的跃迁几率随ｘ变化为中心对ＢａＦＣｌｘＢｒ－１－ｘ：Ｓｍ２＋体系４ｆ５ｄ带的激发光谱、５Ｄ２→７Ｆ０跃迁的荧光衰减随温度的变化特性、５Ｄ２→７Ｆ０的跃迁几率等进行了研究．从而得出结论：在ＢａＦＣｌｘＢｒ１－ｘ：Ｓｍ２＋中，随Ｂｒ含量的增大，４ｆ５ｄ带与５Ｄ２能级更加接近，使７Ｆ０→Ｄ２的吸收截面增大，从而可能提高在５Ｄ２：能级烧孔的效率．     

LaH2分子基态（C2V,A1）的势能函数

在ＱＣＩＳＤ水平上基于相对论紧致有效势（ＲＣＥＰ：Ｒｅｌａｔｉｖｉｓｔｉｃ Ｃｏｍｐａｃｔ Ｅｆｆｅｃｔｉｖｅ Ｐｏｔｅｎ－ｔｉａｌ）方法优化出ＬａＨ２分子的基态为Ｃ２ｖ（Ｘ＾２Ａ１）构型,其〈ＨＬａＨ－１２４４°、平衡核间距Ｒｅ＝２．１９４５Ａ和离子解能Ｄｅ＝５．５９９ｅＶ,并计算出谐振频率：ｖ１＝１２１６．５２１ｃｍ＾－１、ｖ２＝１０８７．４１７ｃｍ＾－１和ｖ３＝２１５６．９５７２ｃｍ＾－１。     

三种丁二炔类衍生物的聚合性能

用半经验ＰＭ３法得到了ＨＤＡＢＳ－１，ＨＤＡＢＳ－２，ＨＤＡＢＳ－３３种丁二炔衍生物的堆积距和堆积角，其值分别为７．３８６Ａ（３８．８７°），６．６９４Ａ（３９．７７°），６．６３５Ａ（４０．１９°），实验证实了衍生物ＨＤＡＢＳ－２的聚合活性比衍生物ＨＤＡＢＳ－要高，这与由ＰＭ３法得到有堆积距和堆积角预测的结果要一致。     

Brans-Dicke理论中的非Accetta真空虫洞解

给出与Ａｃｃｅｔｔａ等人所得到的完全不同的Ｂｒａｕｓ－Ｄｉｃｋｅ（B－Ｄ）理论真空虫洞解，且表明这类虫洞与所得到的其他虫洞不同，其喉的尺度是随着Ｅｕｃｌｉｄｅａｎ宇宙时间的增大而线性增大。     

Brans—Dicke理论中的非Accetta真空虫洞解

给出与Ａｃｃｅｔｔａ等人所得到的完全不同的Ｂｒａｕｓ－Ｄｉｃｋｅ（B－Ｄ）理论真空虫洞解，且表明这类虫洞与所得到的其他虫洞不同，其喉的尺度是随着Ｅｕｃｌｉｄｅａｎ宇宙时间的增大而线性增大。     

析相光度法测定铜（Ⅱ）的研究

本文研究了Ｃｕ－ＰＥＧ－ＤＤＴＣ（铜试剂）（ＮＨ４）２ＳＯ４体系的析相光度法并应用于测定Ｃｕ。最宜酸度为３．６－９．０（ＮａＡｃ－ＨＡｃ，ＮＨ４Ｃｌ－ＮＨ３．Ｈ２Ｏ）缓冲溶液，其络合物的最大吸收位于４５０ｎｍ，表观摩尔吸光系数为９．０５×１０＾３Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，Ｃｕ浓度在０－３０μｇ／Ｌ范围内服从比耳定律，铜与ＤＤＴＣ形成组成为１：２的稳定络合物。该方法用于铝合金中铜的测定，获得了满     

邻啡啰啉─吡啶2，6二甲酸铕二、三元配合物的NMR研究

报道了稀上铕（Ｅｕ３＋）与吡啶－２，６－二甲酸（Ｈ２ＤＰＣ）及邻啡啉（Ｐｈｅｎ）形成的二元和三元固体配合物的制备．对它们进行了元素分析，确定该配合物的组成为二元Ｎａ３［Ｅｕ（ＤＰＣ）３］２Ｈ２Ｏ和三元ＮａＥｕ（ＤＰＣ）２·４Ｈ２Ｏ，对上述配合物的结构作了核磁共振氢谱（１ＨＮＭＲ）、碳谱（１３ＣＮＭＲ）和氮谱（１４ＮＮＭＲ）及红外光谱（ＩＲ）的研究．吡啶－２，６－二甲酸中的羧基以单齿配位（整个分子为三齿配位）．二、三元配合物中铕的配位数分别为９和８．     

NH4Cl作助熔剂合成CaS：Ce的光谱特性及其浓度效应

以ＮＨ４Ｃｌ作助溶剂，碳还原硫酸钙的方法合成了ＣａＳ：Ｃｅ。在紫外光激发下，ＣａＳ：Ｃｅ中存在着Ｃｅ＾３＋的＾２Ｄ－＾２Ｆ５／２（５００ｎｍ）和＾２Ｄ－＾２Ｆ７／２（５５０ｎｍ）跃迁发射，但在蓝色光激发下，只有波峰为５３２ｎｍ半宽度为９２ｎｍ的宽带发射。当Ｃｅ＾３＋的浓度为０．０７５ｍｏｌ％时，＾２Ｄ－＾２Ｆ５／２跃迁发射强度与＾２Ｄ－＾２Ｆ７／２跃迁发射强度相等，而５３２ｎｍ发射猝灭。     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.     

A stereo matching algorithm using multi-peak candidate matches and geometric constraints

Gray cross correlation matching technique is adopted to extract candidate matches with gray cross correla- tion coefficients less than some certain range of maximal correlation coefficient called multi-peak candidate matches. Multi-peak candidates are extracted corresponding to three closest feature points at first. The corresponding multi-peak candidate matches are used to construct the model polygon. Correspondence is determined based on the local geometric relations between the three feature points and the multi-peak candidates. The disparity test and the global consistency checkout are applied to eliminate the remaining ambiguous matches that are not removed by the local geometric relational test. Experimental results show that the proposed algorithm is feasible and accurate.