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1.
火焰原子吸收光谱法连续测定茶叶中的锌、铜和锰   总被引:16,自引:0,他引:16  
本文研究了茶叶中锌、铜、锰微量金属元素的火焰原子吸收分光光度法的测定。方法简便、快速,灵敏度和精密度高,特征浓度锌为0.009μg/mL/1%,铜为0.031μg/mL/1%,锰为0.017μg/mL/1%;相对标准偏差为0.9%~5.0%,回收率92.0%~106.0%。  相似文献   

2.
田树华  张杨 《光谱实验室》2000,17(6):671-674
在近10年内按季度收集了同一个人的头发样品33份和指甲样品,41份,应用火焰原子吸收光谱法测定了人发和指甲中的锰和镍含量,并分别绘制锰和镍随时间(年)变化曲线,获得锰含量波动范围;人发中0.2100-1.500μg/g、指甲中0.8300-2.391μg/g;镍含量波动范围;人发中0.4900-1.750μg/g、指甲中1.179-4.184μg/g。含量变化曲线均具有非线性特征。  相似文献   

3.
导数光谱法同时测定甲硝唑和维生素B6的研究   总被引:7,自引:0,他引:7  
本建立了以0.1mol/LHCl为介质,采用三阶导数光谱法,同时测定甲硝唑和维生素B6的新方法,方法检测限为0.81μg/mL甲硝唑和0.16μg/mL维生素B6,二测定的线性范围均为1.6-22.4μg/mL,直接用于复方甲硝唑片剂中甲硝唑和维生素B6的测定,两种生物的测定变异系数分别小于2.26和2.60%,回收率分别为93-102%和99-101%.  相似文献   

4.
催化分光光度法测定油品中的微量铁   总被引:4,自引:0,他引:4  
在稀硫酸介质中,铁(Ⅲ)能催化过氧化氢氧化中性红使其褪色。本文对轻油的消化条件进行了考察。轻、重油品分别经消化、灰化后可直接测定。摩尔吸收系数3.4×105L·cm-1·mol-1,检出限为0.04-0.05μg/25mL,加标回收率为99.5%-101.7%。  相似文献   

5.
本文建立了火焰原子吸收光谱法测定对氨基乙酰苯胺中的铁的方法。样品用酸分解或灰化处理后进行酸溶。采用氧化性空气/乙炔火焰,于248.3nm波长进行测定,24种金属离子不干扰铁的测定,其特征浓度为0.075μg/mL/1%吸收,DL(3S)为0.014μg/mL,RSD(n=11)为0.72%,标准回收率为98%-103%。本方法与ICP-AES法及分光光度法测定结果一致。  相似文献   

6.
本文叙述了痕量铍在铝合金中的重要作用以及石墨炉原子吸收光谱法测定铝合金中痕量铍的方法研究。该方法用硝酸(1+1)溶解样品。0.10mg/mL以上的铝具有增感效应,铍在0-0.25μg/100mL的范围内具有良好线性关系。该方法操作简便、灵敏度高,特征浓度为1.05×10 ̄(-5)μg/mL/1%。相对标准偏差为1.66%,回收率在96%-102.5%。  相似文献   

7.
Fe(Ⅲ)-灿烂绿-过氧化氢测定痕量铁   总被引:5,自引:0,他引:5  
本文研究了在PH=3.0的酸性条件下,利用铁催化过氧化氢氧化灿烂绿的反应,建立了催化动力学光度法测定痕量铁的新方法。方法检出限为4*10^-9g/mL,线性范围内0.1-1.0μg/25mL,ε=2.50*10^4cm^-1,L.mol^-1,用于水样中痕量铁的测定,结果满意。  相似文献   

8.
本文建立了火焰原子吸收光谱法测量对氨基乙酰苯胺中的铁的方法。样品用酸分解或灰化处理后进行酸溶。采用氧化性空气/乙炔火焰,于248.3nm波长进行测定,24种金属离子不干扰铁的测定,其特征浓度为0.075μg/mL1%吸收,DL(3S)为0.014μg/mL,RSD(n=11)为0.72%,标准回收率为98%—103%。本方法与ICP-AES法及分光光度法测量结果一致。  相似文献   

9.
催化动力学光度法测定水中痕量铁   总被引:4,自引:0,他引:4  
本文研究了ph5.0的HAc-NaAc介质中,痕量铁催化过氧化氢氧化紫脲酸的褪色反应,建立了催化动力学光度法测定痕量铁的新方法,方法的线性范围0-0.40,0.40-2.0μg/25mL,检出限为8×10^-11g/mL,用于水样中痕量铁的测定,结果满意。  相似文献   

10.
本文报道了多波长K系数法测定氯芬待因复方片剂中双氯芬酸钠、磷酸可待因两组分含量的研究。结果表明,双氯芬酸钠在11.18~25.40μg/mL、磷酸可待因在6.785~15.42μg/mL范围内ΔA值与浓度线性关系良好,回归方程分别为ΔA双=-0.00674c双-1.4185×10-3,r=0.9996;ΔA=-0.0130c可-1.822×10-3,r=0.9998。双氯芬酸钠和磷酸可待因的平均回收率及相对标准偏差分别为100.1%,0.36%;100.7%,0.80%。方法简便,快速,结果满意。  相似文献   

11.
Cyclic competition game models, particularly the “rock–paper–scissors” model, play important roles in exploring the problem of multi-species coexistence in spatially ecological systems. We propose an extended “rock–paper–scissors” game to model cyclic interactions among five species, and find that two of the five can coexistent when biodiversity disappears, which is different from the “rock–paper–scissors” game. As the number of fingers is five, we named the new model the “fingers” game, where the thumb, forefinger, middle finger, ring finger, and little finger cyclically dominate their subsequent species and are dominated by their former species. We investigate the “fingers” model in two ways: direct simulations and nonlinear partial differential equations. An important finding is that the number of species in a cyclic competition game has an influence on the emergence of biodiversity. To be specific, the “rock–paper–scissors” model is in favor of maintaining biodiversity in comparison with the “fingers” model when the variables (population size, reproduction rate, selection rate, and migration rate) are the same. It is also shown that the mobility and reproduction rate can promote or jeopardize biodiversity.  相似文献   

12.
The differences of the pitch and duration of Chinese syllables between Putonghua (PTH) and Taiwan Mandarin (TM) were studied. The speech materials to be used are not only isolated syllables, but also sentences. The results reveal that: For the isolated syllables, T1 and T2 in TM are influenced by Minnan dialect, therefore their pitch are lower than those in PTH. T3 is fall-rise in PTH, while it is fall in TM. Moreover, the syllable duration sequence for different tone is T3〉T2〉T1〉T4 in PTH, while it is T1〉T2〉T3〉T4 in TM. For the syllables in sentences, T2 is mid-rise in PTH, while it is mid-level in TM. And the T3 is longer than T4 but shorter than T1 or T2 in PTH, while it is the shortest in TM. Furthermore the effects of prosodic phrase boundary on duration for different tones are almost the same in PTH, but the lengthening part of T1 or T2 is longer than that of T3 or T4 in TM.  相似文献   

13.
Downstep in pitch contour of Chinese Putonghua is examined using subtly designed sentences by controlling tone combinations. The results show both automatic and nonautomatic downstep phenomena exist in Chinese. In non-automatic downstep, low tones compress downwards the pitch range of the following syllables. and the main influence of downstep is on topline. Low tone not only lower the topline behind it, but also raise the high tones before it, the effects are compatible with each other. In automatic downstep, the topline of pitch contour in intonational phrase is presented as a linear downtrend, but it differs among speakers due to the effect of personal stress practice. In comparison with downstep phenomenon in other tone or non-tone languages, the downstep ratio in Chinese is not constant, and the domain of downstep is not limited within the adjacent tones.  相似文献   

14.
It is shown that SU(2) QCD admits an dual Abelian-Higgs phase, with a Higgs vacuum of a type-Ⅱ superconductor. This is done by using a connection decomposition for the gluon field and the random-direction approximation. Using a bag picture with soft wall, we presented a calculational procedure for the glueball energy based on the recent proof for wall-vortices [Nucl. Phys. B 741(2006)1].  相似文献   

15.
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   

16.
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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19.
Based on the research in Ref. [5][Materials Science and Engineering, 1989; A122: 57 63], an improved model of heat source is set up, the different modes of Lamb wave in an isotropic sample generated by a chopped electron beam at frequency f are obtained with integral transform and normal function expansion method, and the output signal of PZT coupled at the back surface of the sample is found out. The generation mechanism of SEAM (Scanning Electron Acoustic Microscopy) signal is discussed. It shows that the SEAM is a near field imaging technique with high spatial resolution and its best lateral spatial resolution is about 2√2α (α is the radius of the focused electron beam). Some of experimental results of SEAM images are presented in the paper and it shows that the spatial resolution of SEAM is better than 0.5 μm and smaller than the thermal diffusion length of the sample. Therefore the character of near field imaging in SEAM is also proved experimentally.  相似文献   

20.
Transmission spectra of coupled cavity structures (CCSs) in two-dimensional (2D) photonic crystals (PCs) are investigated using a coupled mode theory, and an optical filter based on CCS is proposed. The performance of the filter is investigated using finite-difference time-domain (FDTD) method, and the results show that within a very short coupling distance of about 3λ, where λ is the wavelength of signal in vacuum, the incident signals with different frequencies are separated into different channels with a contrast ratio of 20 dB. The advantages of this kind of filter are small size and easily tunable operation frequencies.  相似文献   

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