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本文研究了一种新的在线流动注射-溶剂萃取预富集-原子吸收光谱分析方法。它具有原理简单,萃取装置,萃取效率高,易操作等特点,经对地表水,人发和中草药中Mn(Ⅱ)进行在线FIA-EXT-AAS分析得到比较好的结果。方法检出限为0.076μg.ml^-1,RSD1.02%线性范围0.5-5.0μgm.ml^-1回收率94-102%。 相似文献
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利用双光子吸收,将Na(3S)原子激发到4D态,测量了Na(4D)+Na(3S)=Na(4F)+Na(3S)碰撞能量转移截面,因为直接由4F→3D的荧光不能探测,所以检测3D→3P级联荧光讯号。结合基态钠原子密度的测量,给出了截面值σ4D→4F-1.3×10^-14±28%(cm^2)。 相似文献
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溶剂萃取原子吸收光谱法测定建材样品中微量铁 总被引:8,自引:1,他引:7
本文研究了在微酸性介质中用抗坏血酸还原Fe(Ⅲ),Fe(Ⅱ)与1,10-二氮杂菲(phen)形成Fe(phen)^2+3配合物,加入ClO^-4阴离子与之形成离子缔合物,再用有机溶剂硝基苯萃取,火焰原子吸收测定有机相。本法检出限为1.1ng/mL,回收率为98.5%-106%。 相似文献
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D2EHPA萃取稀土的有机相红外光谱及添加DMHPA的影响 总被引:6,自引:1,他引:5
本文研究了部分皂化的二(2-乙基己基)磷酸(D2EHPA)-正庚烷体系萃取稀土离子Y^3+,Pr^3+,Nd^3+,Eu^3+后有机的傅里叶变换红外光谱(FT-IR)。发现不同稀土离子与萃取剂的配位能力有差异,并且皂化度对萃取有机相中的P=O谱带的频率和吸收强度皆有影响,在D2EHPA中加入二(1-甲基庚基)磷酸(DMHPA)导致P=O谱带形状和吸收强度发生变化。 相似文献
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本文研究了一种新的在线流动注射-溶剂萃取预富集-原子吸收光谱分析方法。它具有原理简单,萃取装置方便,萃取效率高,易操作等特点。经对地表水、人发和中草药中Mn(Ⅱ)进行在线FIA-EXT-AAS分析得到比较好的结果。方法检出限为0.076μg·ml-1,RSD1.02%,线性范围0.5~5.0μg·ml-1,回收率94~102% 相似文献
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本文采用双柱在线离子交换预浓缩FIA-ICP系统,建立了水及土壤浸出液中痕量钼的测定方法。用内装Dowexl(Cl^-1型)阴离子交换树脂微型柱吸附待测元素,然后用洗脱剂(1.9mol/L氯化铵-0.4mol/L柠檬酸铵混合液^[5])洗脱。在采样频率为12样/小时的速度下,浓缩倍数可达50倍。样品(自来水)回收率为90-110%;在0.2μg/ml水平时,变异系数为5.3%(n=11)。 相似文献
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本文用多通道量子数亏损理论(MQDT)对镁原子MgI单激发Rydberg序列3Snd^1,3D2激发态能级结构和能态寿命进行了理论分析和详细的计算,预言了3snd^1,3D2序列n≤30的未知能级及其寿命值,此外,我们还首次预言了实激发态3P^2^1D2能级位于54330.26cm^-1处。 相似文献
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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. 相似文献
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Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide 总被引:1,自引:0,他引:1
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. 相似文献
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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. 相似文献
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S. G. Nedel’ko M. A. Krysyuk A. L. Apanasenko L. N. Lymarenko Z. T. Moroz 《Journal of Applied Spectroscopy》1997,64(1):55-61
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. 相似文献
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A multi-conjugate adaptive optics (MCAO) can offer a possibility of widening field of view (FOV) characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle's expressions of two deformable mirrors (DMs) MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance. 相似文献
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Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use. 相似文献
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References: 《声学学报:英文版》2008,27(1):23-33
The performance of port/starboard discrimination of dual-line array will be seriously degraded when the space between the two line arrays of the dual-line array is mismatched. The directivity function of the delay-sum and delay-subtract beamforming is deduced and the port/starboard discrimination of the delay-sum and delay-subtract beamforming is also studied both under the ideal status and the status under which the space between the two line arrays of the dual-line array is mismatched. Analysis results show the delay-subtract beamforming has better performance of port/starboard discrimination. At last, the sea trial results demonstrate the theoretical results. 相似文献
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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. 相似文献
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With a novel light-weight and absolutely calibrated ultraviolet (UV) spectrometer, UV skylight radiances and O3 slant column densities are measured by balloon-borne limb measurements in Xinjiang area, China. UV skylight radiances measured at the height of 31 km are compared with the results from Modtran in the wavelength range from 290 to 420 nm. O3 slant column densities are derived from radiance spectra in the Huggins bands (320 - 335 nm) using differential optical absorption spectroscopy method. And the parameter exhibits a good correlation with the same value simulated by radiative transfer model (Tracy). The O3 profile simultaneously measured by an O3 sonde is used as input in Tracy calculations. The O3 sonde is launched on the same balloon. 相似文献