流动注射固相预富集原子吸收光谱法测定铁和钴

研究了用邻菲罗啉为配合剂,Ｃ１８键合硅胶为固相富集材料,流动注射在线固相萃取预富集火焰原子吸收法测定痕量铁和钴的方法。该方法自动化程度高,选择性强。经３０ｓ预富集、方法的采样速度达９０次／ｈ,铁和钴的富集倍数分别达１９倍和２０倍,检出限分别达３μｇ／Ｌ和６μｇ／Ｌ。     

5-溴水杨基荧光酮-溴化十六烷基三甲铵荧光熄灭法测定微量钼的研究

本文报道了在溴化十六烷基三甲铵（ＣＴＭＡＢ）存在下,以５－溴水杨基荧光酮（５－ＢｒＳＡＦ）作为荧光试剂,用荧光熄灭法测定微量钼的新方法。详细研究了各种条件实验。反应的适宜酸度范围为 ０．０８－０．２４ｍ ｏｌ·Ｌ－ １ ＨＣｌ,钼含量在０－ ４．０μｇ／２５ｍ Ｌ范围内呈线性关系,配合物的组成比为Ｍｏ（Ⅵ）∶５－ＢｒＳＡＦ∶ＣＴＭＡＢ＝ １∶２∶２,激发波长为３６５ｎｍ ,发射波长为５２５ｎｍ 。方法灵敏度高,检出限为２．０μｇ／Ｌ。用于样品中微量钼的测定,结果令人满意。     

5′-硝基-水杨基荧光酮-溴化十六烷基 三甲胺荧光猝灭法测定微量锆

本文基于Ｚｒ（Ⅳ）－５′－硝基－水杨基荧光酮（５′－Ｎ－ＳＡＦ）－溴化十六烷基三甲铵（ＣＴＭＡＢ）体系的荧光猝灭效应,提出一种测定微量锆的新荧光分析方法。在０．８～１．２ｍｏｌ／Ｌ的Ｈ２ＳＯ４介质中,在ＣＴＭＡＢ存在下,锆与５－Ｎ－ＳＡＦ生成组成比为１∶４的橙红色络合物。该体系存在两个激发峰,其激发波长分别为λｅｘ１＝４７５ｎｍ,λｅｘ２＝５０５ｎｍ,发射波长λｅｍ＝５２５ｎｍ。锆（Ⅳ）浓度在２．０～８０μｇ／Ｌ呈良好线性关系,检出限为２．０μｇ／Ｌ。本法灵敏度高,选择性好,用于铝合金中微量锆的测定,获得满意结果。     

膜富集分光光度法测定痕量铜的研究

本文以ＰＡＮ为显色剂，用ＷＸ型混合纤维素滤膜（孔径为０．６５μｍ，２５ｍｍ）富集分离，用乙醇溶解富集物Ｃｕ－ＰＡＮ，分光光度法测定微量铜，Ｃｕ－ＰＡＮ在乙醇溶液中最大吸收波长为５６０ｎｍ，表观摩尔吸光系数为３．７３×１０－４Ｌ·ｍｏｌ－１·ｃｍ－１。铜量在０．２－１０．０μｇ／５ｍＬ范围内符合比耳定律，该法具有灵敏度高、操作简便、快速、线性范围宽等优点。方法应用于食品、水样中铜的测定，结果满意     

ICP－AES法分析水质的探讨

本文用ＩＣＰ－ＡＥＳ（电感耦合等离子体－原子发射光谱法）测定水中Ａｌ、Ｂ、Ｂａ、Ｂｅ、Ｃａ、Ｃｄ、Ｃｏ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｇ、Ｍｏ、Ｍｎ、Ｎｉ、Ｐｂ、Ｓｒ、Ｖ、Ｚｎ等１８种微量元素。方法简便、快速，只将样品简单酸化，即可测定。方法检出限为０．０００５－０．５μｇ／ｍＬ。相对标准偏差＜１８％     

激光蒸发进样ICP－AES测定地质祥品中的钡和锶

本文讨论了用连续ＣＯ＿２激光器蒸发地质粉末样品，ＩＣＰ－ＡＥＳ测定Ｂａ和Ｓｒ。在样品中加入适量的粘合剂和石墨粉混匀压饼，用激光全部蒸发。在蒸发室出口处加入了一只多层多孔过滤器，一定程度上改善了系统长时间工作的稳定性。对影响激光采样和ＩＣＰ－ＡＥＳ分析性能的参数进行了研究。实验结果表明，连续激光蒸发地质粉末样品、ＩＣＰ－ＡＥＳ测定Ｂａ、Ｓｒ，大部分分析结果满意。在选择的系统条件下，Ｂａ、Ｓｒ的检出限分别为２．６μｇ·ｇ￣－１和３．０μｇ·ｇ￣－１；精密度ＲＳＤ分别为６．３％（４７０μｇ·ｇ￣－１）和５．６％（５２μｇ·ｇ￣－１）     

痕量钴、镍和镉的流动注射在线共沉淀预浓集的研究及其FAAS测定

本文应用流动注射分析技术为痕量钴、镍和镉的火焰原子吸收光谱测定建立了一个有效的在线共沉淀预浓集系统。钴、镍和镉离子在弱酸性介质中与ＡＰＤＣ－Ｆｅ２＋产生共沉淀，共沉淀反应和沉淀收集在编结反应器中同时进行。用甲基异丁基甲酮溶洗沉淀在线引入火焰原子化器中进行测定。分析速度为７２样／ｍｉｎ，样品消耗量为１．１ｍｌ以及装样时间３０ｓ时，测定钴、镍和镉获得的增感系数分别为４２、３０、３３。测定含量水平分别为２０．０、１００．０和１０．０μｇ／ｌ，钴、镍和镉的相对标准偏差为２．３％、２．０％和２．４％（ｎ＝１１）。测定钴、镍和镉的检出限（３σ）分别为１．０、３．０和０．３μｇ／ｌ。对尿样标准参考物（ＧＢＷ０９１０３）中镍和镉及动物组织牛肝标准参考物（ＮＢＳ１５７７ａ）中钴的测定结果与标准值一致     

FAAS法测定对氯基乙酰苯胺中的铁

本文建立了火焰原子吸收光谱法测定对氨基乙酰苯胺中的铁的方法。样品用酸分解或灰化处理后进行酸溶。采用氧化性空气／乙炔火焰，于２４８．３ｎｍ波长进行测定，２４种金属离子不干扰铁的测定，其特征浓度为０．０７５μｇ／ｍＬ／１％吸收，ＤＬ（３Ｓ）为０．０１４μｇ／ｍＬ，ＲＳＤ（ｎ＝１１）为０．７２％，标准回收率为９８％－１０３％。本方法与ＩＣＰ－ＡＥＳ法及分光光度法测定结果一致。     

FAAS法测定对氨基乙酰苯胺中的铁

本文建立了火焰原子吸收光谱法测量对氨基乙酰苯胺中的铁的方法。样品用酸分解或灰化处理后进行酸溶。采用氧化性空气／乙炔火焰，于２４８．３ｎｍ波长进行测定，２４种金属离子不干扰铁的测定，其特征浓度为０．０７５μｇ／ｍＬ１％吸收，ＤＬ（３Ｓ）为０．０１４μｇ／ｍＬ，ＲＳＤ（ｎ＝１１）为０．７２％，标准回收率为９８％—１０３％。本方法与ＩＣＰ－ＡＥＳ法及分光光度法测量结果一致。     

膜溶解富集分光光度法测定微量锰的方法研究

本文以５－Ｂｒ－ＰＡＤＡＰ为显色剂，用ＷＸ型纤维素滤膜为富集分离膜测定微量锰。使用乙醇溶解捕集物，Ｍｎ－５Ｂｒ－ＰＡＤＡＰ在乙醇溶液中最大吸收波长为５６３ｎｍ，表观摩尔吸光系数为９．３２×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１。锰浓度在０．１－５．０μｇ／５ｍＬ范围内符合比耳定律，该法灵敏度高，操作简便，方法应用于食品，水样中锰的测定结果满意。     

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.     

Hybrid Wavelength and Code Division Multiple Access in Optical Networks

A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.     

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.