电感耦合等离子体质谱测定土壤中的有效硼

以沸水提取土壤中的有效硼,不经分离富集,电感耦合等离子体质谱法直接测定土壤样品中的有效硼.方法检出限可达0.016μg/g,通过对国家土壤有效态一级标准物质测试,测定结果基本一致;GBW 07412标准物质11次测定的相对标准偏差(RSD)为1.03%.     

电感耦合等离子体-质谱测定石灰性土壤中的有效磷

采用电感耦合等离子体一质谱法测定石灰性土壤中的有效磷,方法检出限为0.090μg/g.通过对国家土壤有效态一级标准物质和行业标准物质测试,测定结果与标准值基本一致;对GBW 7413、GBw 7414、ASA-8、ASA-9标准物质进行11次测定的相对标准偏差(RSD)均小于5%.     

秦巴山区汉中中药材姜黄中无机元素的测定

用ICP-AES测定陕西汉中市中药姜黄中的2种常量营养性元素(钙、镁)和5种微量元素(铜、铬、铁、锌、锰)含量.钙6010.5μg·g-1、镁6250.1μg · g-1、铜18.8μg·g-1、铬4.2μg·g-1、铁331.8μg·g-1、锌208.6μg·g-1、锰477.4μg·g-1,加标回收率均在96.4％...     

秦巴山区中草药钮子七中微量元素的测定

用ICP-AES测定了秦巴山区独有的中草药钮子七中的2种常量营养性元素(钙、镁)和5种微量元素(铜、铬、铁、锌、锰)含量。钙4790.66μg.g-1、镁55.32μg.g-1、铜18.44μg.g-1、铬2.1μg.g-1、铁264.50μg.g-1、锌56.71μg.g-1、锰17.83μg.g-1,回收率均在96.2%—100.5%之间,结果表明,此方法简便、可靠,具有良好的精确度和准确性。并初步讨论了中草药钮子七中有益元素与治疗疾病的关系,并与中药材汉三七中微量元素含量相比较,二者微量元素含量略有差异。     

湿式消解-ICP-AES同时测定猪组织器官中的7种金属元素

建立湿式消解-ICP-AES测定猪组织器官中7种金属元素含量.对猪肉、猪肝、猪肚15份样品,采用湿式消解法进行前处理,利用ICP-AES测定铁、锰、铜、锌、镉、铅、铬7种金属元素含量.方法检出限为0.230-3.501μg/L、线性范围为0.01-6.00μg/mL、相关系数为0.99961-0.99997、加标回收率为90.4％-96.8％、相对标准偏差为1.03％-3.12％.经实际检测,猪产品中含有丰富的人体必需的金属元素铁、锌、铜,特别是猪肝中的铁和锌含量较高,铁最高达到160.3mg/kg,锌最高达到113.4mg/kg.结果显示3种猪组织器官是人体补充铁、锌金属非常有益的营养食品.     

微波消解-ICP-AES测定植物样品中多种微量元素

用微波消解仪消解植物样品,ICP-AES同时测定样品中硼、硫、磷、钾、钠、钙、镁、铜、锌、锶、钡、锰、铁等13个元素。方法检出限为0.087-6.03μg/g,精密度（RSD%,n=12）为0.49%—2.28%。对大米、茶叶、豆角、紫菜、花粉、黄芪国家一级标准物质进行测定,测定值与推荐植相符。结果表明,该方法可以满足植物样品中微量元素测定的要求。     

FAAS法测定硫酸中的铜、铁和锌

采用火焰原子吸收光谱法测定硫酸中铜、铁和锌,确定了最佳仪器工作条件和样品处理方法.在选择好的实验条件下,测定铜的特征浓度为0.005μg/mL/1%;铁的特征浓度为0.014μg/mL/1%吸收;锌的特征浓度为0.002μg/mL/1%吸收.回收率分别为铜97.7%-98.2%,铁98.2%-99.4%,锌96.8%-98.7%.     

微波消解ICP-MS测定尿样中硒及其他重金属元素

建立微波消解电感耦合等离子体-质谱法(ICP-MS)同时测定尿样中硒及铬、镉、砷、铅、锰、钴、镍、铜、锌10种重金属元素的方法。采用硝酸-过氧化氢消解体系,微波消解法制备样品.以铟、铋为内标物质,直接用ICP-MS测定上述10种元素。所测10种元素的检出限为0.006-0.073μg/L,校准曲线线性关系好(r>0.9999),相对标准偏差(RSD)均小于3%,对尿样标准物质的测定值均在标准参考值范围内。应用微波消解ICP-MS分析尿样,方便快捷,灵敏度高,检出限低,重现性好,是理想的生物样本检删分析方法。     

基体改进-石墨炉原子吸收光谱法测定中药丹参中的铜和锌

以 NH4NO3 和 Se Triton X- 10 0作为铜和锌的基体改进剂 ,石墨炉原子吸收法测定丹参中铜和锌的含量。优化了实验条件 ,灰化温度分别提高到 12 0 0℃和 90 0℃ ,提高了方法的灵敏度。研究了不同测定波长对实验的影响 ,消除了基体干扰 ,提高了方法的重现性。用校准曲线法和标准加入法对试样分析结果一致 ,铜和锌的方法检出限分别为 0 .6 ng/ m L和 0 .9μg/ m L,RSD分别为 1.8%和 2 .3% ,回收率分别为 96 %和 10 1%。     

FAAS测定电解镉中的Zn、Cu和Fe

采用火焰原子吸收光谱法测定电解镉中铜、铁和锌的方法,确定了最佳仪器工作条件和样品处理方法.在选择好的实验条件下.测定铜的特征浓度为0.006#g/mL/1%吸收;铁的特征浓度为0.015μg/mL/1%吸收;锌的特征浓度为0.0031μg/mL/1%吸收.回收率分别为铜97.5%-98.0%,铁99.1%-100.2%,锌97.4%-99.1%.     

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.     

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.     

Fiber Modal Index Measurements Based on Fiber Gratings

A novel method based on fiber gratings for measuring the effective indices of fiber modes is proposed. The effective index difference between the core mode and a cladding mode was obtained by analyzing the interference fringe of a pair of cascaded long-period fiber gratings. In order to extract the core mode index from the measured index difference, an index matching oil immersion method is proposed. By analyzing the interaction between the cladding mode and the oil applied on the cladding surface, the mode order and the effective index of the involved cladding mode might be calculated. Experimental results about the interference fringe shifts induced by the oil index and the oil-applied length are also presented.     

Optical Pulse Compression Schemes That Use Nonlinear Bragg Gratings

Nonlinear optical pulse compression of picosecond pulses typically requires long lengths of optical fiber and multiple components. Periodic structures, such as fiber Bragg gratings, are highly dispersive at wavelengths outside of the photonic bandgap. This implies that such gratings can be used as very short all-fiber compressors. In this paper a number of such compression schemes are reviewed involving uniform and nonuniform fiber Bragg gratings, relying on both soliton and nonsoliton compression principles. Experimental results supporting the corresponding underlying theory are also presented. Finally, an extension of one of the compression schemes is shown, which allows the generation of adjustable high-repetition rate soliton trains.