电感耦合等离子体-质谱法同时测定地下水中微量B、P、Br和I

研究并建立了电感耦合等离子体-质谱法(ICP-MS)同时测定地下水中B、P、Br和I的方法,考察了标准之间的相互影响,B、P、Br、I的检出限分别为0.8864、1.286、0.6875、0.1242μg/L.加标回收率在98.60％-104.4％之间,研究了乙酸和乙醇在ICP-MS中的增强效果,发现乙酸的增敏效果优于乙醇.     

电感耦合等离子体-原子发射光谱法测定新锆合金(锆-锡-铁-铬-铌)中10种微量杂质元素

IPC-AES测定了新锆合金中10种微量杂质元素Al、Co、Cu、Mg、Mn、Mo、Ni、Pb、Ti和V.试液浓度为10mg/mL时,测定范围在20-1060μg/g之间,回收率在94%-108%之间,相对标准偏差(RSD,n=6)为4.3%-7.4%之间.     

二阶导数光度法测定豆奶粉中微量铜

在含有乳化剂OP(聚乙二醇辛基苯基醚)的pH值为9.2的磷酸氢二钠缓冲溶液中,以1-(2-吡啶偶氮)-2-萘酚(PAN)为显色剂,在566nm波长处用二阶导数分光光度法测定铜,可消除锌、镉的干扰.校准曲线回归方程A=0.0976C 0.0038,线性范围0.025-2.1μg/mL,相关系数r=0.9992.检出限为5.5×10-6g/L,相对标准偏差RSD为2.37%,测定豆奶粉中铜的回收率在95%-102%之间,结果令人满意.     

原子吸收光谱法测定中药厚朴中的铜、铁和钙

用硝酸-高氯酸（4∶1）混合液对厚朴进行消解,然后采用原子吸收光谱法测定厚朴中铜、铁、钙的含量.结果表明,厚朴中含铜4.41μμg/g,含铁55.5 μg/g,含钙6872.5μg/g,加标回收率在93.6％-100.1％之间.该方法测定中药中金属离子的含量方法简便、快速、灵敏.该结果可为进一步研究厚朴的相关药理作用提供参考依据.     

微波消解-电感耦合等离子-质谱法测定船用燃料油中钒、铝、钙、锌、镍、钠、铁和硅

船用燃料油样品经微波消解后,采用电感耦合等离子-质谱法(ICP-MS)测定其中的钒、铝、钙、锌、镍、钠、铁和硅含量。方法在0—100μg/L范围内线性良好,仪器检出限为0.005—12.89μg/L,其回收率在90.39%—107.48%之间,相对标准偏差小于2.0%。本方法具有检出限低、准确度高、精密度好和多种元素同时测定等优点,完全满足船用燃料油实际样品的测试需要。     

HG-AFS同时测定锌锭中的砷和汞

采用盐酸分解样品,用聚环氧琥珀酸(PESA)掩蔽基体,建立了氢化物发生-原子荧光光谱法(HG-AFS)测定锌锭中砷和汞的方法.实验表明,0.1g锌锭溶解后加入2.0mL PESA可以有效地掩蔽基体元素Zn,共存元素Mg、Al、Cu、Sb和Sn不干扰As和Hg的测定.砷和汞的方法检出限分别为0.26μg/L和0.043μg/L.将方法应用于实际样品分析,砷和汞的相对标准偏差(RSD,n=5)分别在1.1％-2.0％和1.0％-1.6％之间.加标回收率分别为96.1％-120.0％和92.8％-108.8％.     

二极管阵列紫外分光光度法测定西埃斯

利用紫外分光光度法对西埃斯进行检测,在0.2072-10.36μg/mL浓度范围内线性关系良好(R2=0.9990),检出限为0.0518μg/mL,相对标准偏差(RSD)为0.82％,回收率在99.3％-100.1％之间.本法操作简便,准确,能较好的应用于气溶胶中痕量西埃斯的测定.     

整体柱毛细管电色谱法测定蔬菜中有机磷农药的含量

采用加压毛细管电色谱法,在整体柱上实现了马拉硫磷、二嗪农、甲基对硫磷、杀螟硫磷、倍硫磷、甲基毒死蜱和毒死蜱等 7 种有机磷类化合物的分离检测.整体固定相具有渗透性好,传质速度快等优点,7种物质10min内实现快速分离测定.在最佳电色谱条件下,马拉硫磷、二嗪农、甲基对硫磷、杀螟硫磷、倍硫磷、甲基毒死蜱和毒死蜱的线性范围分别为2-50μg/mL,2-50μg/mL,2-50μg/mL,2-50μg/mL,1.4-50μg/mL,2.5-50μg/mL,2.5-50μg/mL;相关系数r2为0.9925-0.9984;检测限(S/N=3)在0.3-1.5μg/mL之间.本法操作简单、快速,适合于蔬菜中有机磷农药残留的分析测定.     

顺序注射氢化物发生-原子荧光光谱法测定化肥中砷、汞、锑和硒

本文建立了一种顺序注射氢化物发生 -原子荧光光谱法测定化肥中 As、Hg、Sb、Se含量的方法。在最佳条件下 ,As、Hg、Sb和 Se的检出限分别为 0 .1 5μg/ L、0 .0 6 1μg/ L、0 .0 4 6μg/ L、0 .2 5μg/ L。测定化肥中 As、Hg、Sb和 Se,回收率均在 94 .6 7%— 1 0 6 .81 %之间。该方法用于检测化肥中 As、Hg、Sb和 Se具有很好的可行性和实用性。     

火焰原子吸收光谱法测定黄芪、甘草、广藿香中的铜

用硝酸-高氯酸混合酸(4 1)消解黄芪、甘草、广藿香,在波长324.7nm处,用火焰原子吸收光谱法测定黄芪、甘草、广藿香中铜的含量.线性回归方程为A=0.1861C 0.0007,相关系数r=0.9998,线性范围为0-7μg/mL,检出限为0.0032μg/mL,测定结果的相对标准偏差为0.061%,加标回收率为98.7%-103.0%.     

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.