有机相直接进样ICP-OES快速测定车用汽油中微量硅（英文）

车用汽油样品用异辛烷溶剂适当比例稀释,直接进入电感耦合等离子体光谱仪(ICP-OES)测定硅元素。考察了稀释溶剂及稀释比例、标准物质类型、样品冷却温度、汽油样品组成等因素对硅含量测定的影响。结果表明,汽油样品用异辛烷按1∶1的比例混溶,在雾化室冷却温度为-10℃时,直接进入ICP-OES测定硅含量效果最佳。在优化的工作条件下,该方法在0.1~10.0 mg·kg~(-1)硅含量范围内线性良好,线性相关系数达0.999 96,检出限为0.012 mg·kg~(-1),回收率在95.8%~98.4%之间,相对标准偏差小于3.0%。该法简便、快速、准确度高,适用于车用无铅汽油、车用乙醇汽油和低比例甲醇汽油中微量硅的快速检测。     

火焰原子吸收光谱法测定氢甲酰化反应液中铁

利用冰醋酸作溶剂,采用火焰原子吸收光谱法直接测定氢甲酰化反应液中的总铁含量,以1mol/L盐酸萃取样品,有机相与无机相分虽用冰醛酸稀释后用火焰原子吸收法测定,可分虽得到样品中有机铁与无机铁的含量,方法简便、快速、可靠。具有较好的精密度和准确度,回收率为93．5％－109％,相对标准偏差为1．0％－2．7％,方法的特征浓度为0．585μg/mL/1%.     

ICP-OES雾化系统对汽油中不同硅化学形态测量的适应性研究

汽油中含硅化合物的存在会在燃烧时形成二氧化硅沉积于汽车燃烧系统的不同部位,进而导致车辆故障的发生。汽油中的含硅化合物可能以不同的形态存在。采用有机直接进样模式的电感耦合等离子体发射光谱(ICP-OES)法测定油品中的微量杂质因其方便、快速正得到越来越多的应用。本文研究了不同的ICP-OES雾化系统对不同形态含硅化合物测量的影响。对于微量旋流雾化系统,硅的发射强度与硅化学形态有明显关系,硅化合物挥发性越大,硅元素的发射强度就越强。微量可控温旋流雾化系统可改善易挥发性硅元素的发射强度增强效应,但仍无法完全消除此增强效应。直接注入高效雾化器(DIHEN)雾化系统的应用,可有效消除易挥发性硅的发射强度增强效应,比较适合汽油中硅含量的测定。DIHEN-ICP-OES方法的加标回收率为92.8%～108.7%,相对标准偏差(RSD,n=10)为1.05%～4.63%,方法检出限为0.05 mg·kg-1。与传统微波消解法相比,DIHEN-ICP-OES具有简便,快速,灵敏,准确度较高的优点,可用于汽油中硅含量的直接检测。     

电感耦合等离子体发射光谱法测定E10乙醇汽油中的钠和锌

车用乙醇汽油是一种新型、清洁的汽车燃料,在燃烧过程中,微量的重金属杂质对汽车的行驶和养护有着至关重要的影响,一些燃烧产物可能会污染环境,威胁人们的身体健康,因此有必要对其中的微量元素进行控制.以异辛烷稀释汽油样品,电感耦合等离子体发射光谱(IC P-O ES)法测定车用E10乙醇汽油中钠、锌含量的方法,选择钠和锌的分析...     

基体改进剂和L′vov平台技术石墨炉原子吸收光谱法测定全血中铅

应用基体改进剂和L′vov平台技术,石墨炉原子吸收光谱法测定了全血中铅。实验发现,使用含磷酸二氢铵0．6％、硝酸铵0．4％的混合溶液作为基体改进剂,可使血样样品的灰化温度提高到900℃,实际使用灰化温度750℃;用0．3％ Trition X-100稀释血样,可代替消化,经氚灯校正背景,直接测定血样中的铅含量,对六份血样分析结果,相对标准偏差3％－7％,回收率93％－106％,分析方法的灵敏度特征质量为6．0pg/1%。     

高纯La-Ni-Al合金成分及杂质元素的分析方法研究

叙述了镧－镍－铝（La-Ni-Al)合金分镍、铝及微量杂质元素锌、铁、锰、镁、硅、铜和钙的ICP－AES测定方法。样品以HNO3（1＋1）溶解,稀释后直接测定主量元素镍和铝;用基体匹配法补偿基体效应测定其他杂质元素。各元素回收率在95％－106％,相对标准偏差优于5％。     

火焰原子吸收光谱法测定铜镍矿浮选产品中铜、镍、镁

研究了用火焰原子吸收光谱法在同一溶液体系中直接快速测定金川铜镍矿浮选产品中铜、镍、镁含量新的新方法。考察了产品中高含量的SiO2对测定镁的干扰情况，并提出了排除这项干扰简便方法，根据各元素的标准溶液系列的测定数据，推算出了铜、镍、镁3元素的线性回归方程及线性相关系数，特征浓度铜为0．40mg.L^-1/1%，镍为0．48mg.L^-1／1％，Mg为0．018mg.L^-1／1％；线性浓度范围铜，镍均为0－10mg.L^-1，镁为0．2－1．2mg.L^-1。相对标准偏差铜为2．5％(n=6)，镍为2．3％（n＝6），镁为2．8％（n=6），加标回收率铜为96．5％－102．5％，镍为98．8％－103．5％，镁为98．2％－102．5％，这种方法操作简便，快速，实用，具有较好的精密度和准确度，实际产品分析结果与外检单位及金川公司测定的结果吻合。     

茜素红S荧光猝灭法测定壳聚糖含量

在pH 5.0的NaAc-HAc缓冲液中壳聚糖对茜素红S的荧光强度具有明显的猝灭作用,且猝灭程度F0/F与加入的壳聚糖浓度成线性关系,据此建立一种测定壳聚糖含量的荧光猝灭法。确定了最佳测定条件,线性回归方程为F0/F=-0.438 37 0.436 27c(mg·L-1),线性范围为0-16.667 mg·L-1,r=0.996,检测限为0.473 mg·L-1;平均回收率为100.60％,测定了样品中壳聚糖的含量,并考察了干扰因素对测定的影响。采用该方法可测定复杂样品中微量壳聚糖含量。     

超声波辅助溶剂萃取-电感耦合等离子体质谱法测定生物样品中的总汞和甲基汞

建立了超声波辅助溶剂萃取联用电感耦合等离子体质谱法(ICP-MS)测定生物样品中总汞(T-Hg)和甲基汞(MeHg)的分析方法。实验优化了萃取溶剂种类,溶剂浓度,各种辅助方法和超声波振荡时间等各种萃取条件。选择6 mol·L-1 HCl作为溶剂,超声2 h, 以有机溶剂萃取,再以水反萃,稀释后直接进行测量MeHg的含量。此方法可用于同时测定T-Hg和MeHg, 检出限为0.01 ng·mL-1,相对标准偏差为3.44％,线性范围为1～50 ng·mL-1,加标回收率为80%～97%。在此条件下测定了5种不同类型生物标准参考物质的T-Hg和MeHg,测定值与标准值吻合。该法综合了超声波辅助萃取和溶剂微萃取以及ICP-MS的优点,操作简便快速,灵敏度高,适合于各种生物样品中痕量MeHg快速萃取分离和分析。     

可变误差多面体分光光度法同时测定联磺甲氯苄啶片三组分的含量

以可变误差多面体法处理多波长分光光度数据同量测定联磺甲氧苄啶片中三组分的含量，模拟样品中磺胺甲Wu唑、磺胺嘧啶、甲氧苄啶的的回收率分别为98．89％－101．36％、98．18％－100．98．86％－101．75％相对标准偏差为0．81％、0．23％、0．94％。对3个批号实际样品的测定结果与药典方法的测定结果吻合。     

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.