ICP-AES测定地质样品中铍、硼和镓

ICP-AES测定地质样品中的B、Be和Ga.对B在磷酸中的稳定性进行了研究,并有效地控制了B的空白值.方法可信、简便、快速,适用于大批量测试工作.     

ICP-AES测定金合金中钆和铍含量

通过ICP-AES测定金合金中Gd和Be量各种相关因素的试验研究,建立了一个准确可靠的测定方法以替代原国标方法,适用于AuAgCuMnGd、AuAgCuGd、AuNiGd、AuBe合金中钆、铍量的测定,测定含量范围为:0.2%-2%.方法加标回收率:Gd为95.58%-99.98%,Be为96.11%-103.33%.方法测定精密度结果:Gd为1.02%.Be为4.05%.     

密闭溶样-电感耦合等离子体-质谱法测定地质样品中的微量硼

采用酸溶密闭溶样处理样品,电感耦合等离子体-质谱法测定地质样品中的微量硼.方法检出限为0.029μg/g.测定国家标准物质,测定结果均在标准值的允许误差范围内,同一样品11次分析结果的相对标准偏差(RSD)为5.20％.方法简便、结果可靠、使用化学试剂少,适用于大批地质样品的分析测试.     

ICP-MS测定碳酸锂中微量元素

用ICP-MS测定碳酸锂中微量杂质元素的基本条件,确定了合适的样品处理、分解方法,研究了元素间的干扰.方法检出限K0.020μg/g,Na o.025μg/g,Ca0.009μg/g,Mg 0.010μg/g,SO2-4 0.050μg/g;加标回收率在94.0%-102.0%,测定精密度RSD 0.5%-2.1%,方...     

C+轰击铍的分子动力学模拟

使用分子动力学模拟方法研究了入射能量对C⁺离子与Be样品表面相互作用的影响。模拟结果表明,随着C⁺离子的入射能量增大,C⁺离子注入深度也增加,Be原子的溅射产额近似线性增加,而滞留在样品中的C原子数量变化不大,在C⁺离子轰击Be样品的初始阶段,样品中Be原子的溅射产额较大,而随着C⁺离子注入剂量的增加,Be原子的溅射产额逐渐减小并趋于稳定。在此作用过程中,在样品表面形成一个富C层,减缓了样品中Be原子的溅射速率,起到了保护Be样品的作用。     

微波消解ICP-MS/ICP-AES测定沙姜中无机元素

以沙姜为原料,经浓HNO3-30%H2O2处理及微波消解后,用ICP-MS/ICP-AES同时测定K、Mg、Mn、Fe、Pb等无机元素。实验结果表明该法快速简便、准确率高、精密度好,完全可以满足沙姜样品中无机元素测定要求。从检测结果来看沙姜中富含K、P、Mg、Ca、Al、Fe、Na、Mn,其中K含量最高为18600μg/g,而Be、Cd、Tl、Pb含量较低,均低于3μg/g。     

催化动力学褪色光度法测定痕量铜(Ⅱ)研究

研究了在盐酸介质中, 铜(Ⅱ)催化过氧化氢氧化孔雀绿褪色反应的适宜条件与影响因素, 建立了催化动力学光度法测定痕量铜的新方法. 该方法是用固定时间法在615 nm波长处监测催化反应. 方法的线性范围为0～22 μg·L-1, 检出限为1.92×10-9 g·mL-1, 该催化反应对铜(Ⅱ)为一级反应, 表观活化能为122.3 kJ·mol-1, 表观反应速率常数为7.70×10-4 s-1. 因为Fe3+干扰Cu(Ⅱ)的测定, 用PO3-4与Fe3+生成稳定的[Fe(PO4)2]3-络合物, 可掩蔽Fe3+. 方法相对标准偏差为1.16%, 标准加入回收率为98.3%～100.3%. 该方法用于水样品、茶叶样品、奶粉样品以及苹果样品中铜的测定, 获满意结果.     

ICP-AES测定青海三江源地区水中Be、Pb、Cd等对人体有害元素的含量

电感耦合等离子体发射光谱法（ICP-AES）为具有干扰水平低,精密度好,线性分析范围宽和同时多元素分析能力强的特点,已广泛应用于水质、环境、生物样品、食品、临床分析、地质样品、金属材料等的测定。本文利用ICP-AES同时测定水中的Be、Pb、Cd、Cu和Cr这5种元素,方法简便、快速,结果令人满意。     

氢化物发生-原子荧光光谱法测定贻贝中的砷

以 HNO3 - H2 SO4消解样品 ,氢化物发生原子荧光光谱法测定了贻贝中的砷。研究了消化方法、介质及酸度、还原剂浓度、硫脲 -抗坏血酸用量、干扰离子等对测定的影响。在最佳试验条件下 ,荧光强度与砷浓度在 0 .174 5— 2 0 0 .0 μg/L范围内呈线性关系 ,相关系数 r为 0 .9990 ,检出限为 0 .0 349μg/L。标准样品的推荐值和 ICP- AES分析结果相符。方法简便、快速、灵敏、准确。     

ICP-MS同时测定水产品中的铅、镉、汞和砷

以电感耦合等离子体-质谱法同时测定国家标准物质扇贝中4种元素,研究了此法测定水产品铅、镉、汞和砷,4种元素的校准曲线、检出限、精密度和准确度.ICP-MS测定4种元素均在扇贝样品标准值的允许误差范围之内,铅、镉、汞、砷检出限分别为0.06、0.01、0.26、0.20μg/kg.精密度都在10％以下,符合方法确认要求.     

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.