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1.
本文详细考查了巯基棉富集Fe(Ⅲ)的条件,发现微量铁(Ⅲ)的PH值为5-8的条件下能为巯基棉定量吸附,1mol/L盐酸5mL能将巯基棉吸附的Fe(Ⅲ)定量洗脱,0.1g巯基棉的饱和吸附量为90μg,样品分析测定结果的相对标准偏差小于3.4%,加标回收率为98.4%-98.8%。  相似文献   

2.
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   

3.
基于pH4.0的弱酸性介质中铁离子对过氧化氢氧化固绿FCF褪色反应的催化作用,提出了催化褪色光度法测定痕量铁的新方法。研究了该方法的适宜反应条件,方法的检出限为9.7×10-7gFe(Ⅲ)/L,线性范围为0-1.5μgFe(Ⅲ)/25mL,方法用于水中痕量铁的测定,结果满意。  相似文献   

4.
本文研究了新显色试剂8-喹啉偶氮槲皮素的合成方法及其理化性质,显色性能和与Fe(Ⅲ)的显色反应条件,在TweeN-80存在下,PH=10.3的NH3-NH4Cl缓冲介质中,Fe(Ⅲ)与8-QAQ的络合物在500nm处有最大吸收,表观摩尔吸光系数为1.06×10^5L·mol^-1·cm^-1,Fe(Ⅲ)含量在0-2.6μg/10mL范围内符合比耳定律。在室温下,络合物至少稳定15h,络合比为1:3  相似文献   

5.
基于PH4.0的弱酸性介质 离子对过氧化氢氧化固绿FCF褪色反应的催化作用,提出了催化褪色光度法测定痕量铁的新方法。研究了该方法的适宜反应条件,方法的检出限为9.7×10^-7gFe(Ⅲ)/L,线性范围为0-1.5μgFe(Ⅲ)/25mL方法用于水中痕量铁的测定,结果满意。  相似文献   

6.
乳酸亚铁中总铁的溶样及比色测定   总被引:2,自引:0,他引:2  
本文研究在HNO3-HCl体系乳酸亚铁中的Fe^2+会被氧化成Fe^3+,用碘基水杨酸比色法就能准确测定总铁量,回收率在98%-100%,相对标准偏差为1.14%,摩尔吸光系数为5.6×10^4L.mol^-1.cm^-1,含铁量在0-700μg/100mL范围内符合比耳定律。  相似文献   

7.
本文研究了铁(Ⅲ)-PEG(聚乙二醇-2000)-钍试剂-Na2SO4体系的析相光度法并应用于测定Fe(Ⅲ),最适酸度为4.6(NaAc-HAc)缓冲溶液,其络合物的最大吸收位于566nm,表观摩尔吸光系数为8.06×103L·mol-1·cm-1。Fe(Ⅲ)浓度在0—30μg·mL-1范围内服从比耳定律,该方法用于发样中铁的测定,获得了满意结果  相似文献   

8.
ICP-AES法测定铝锂合金中Li、Mg、Fe、Cu、Si、Zr的研究   总被引:1,自引:0,他引:1  
李莉  潘傥  徐普德 《光谱实验室》1999,16(4):434-438
本文研究了采用ICP-AES技术同时测定铝锂合金中Li、Mg、Fe、Cu、Si、Zr等六元素的分析方法,优化了工作条件,经对合成样品和实际样品测量,对Li(1%-4%)、Mg(0.5%-6%)、Fe(0.05%-2.5%)、Cu(0.5%-5%)、Si(0.05%-0.5%)、Zr(0.05%-0.5%),方法的相对标准偏差均小于5%,回收率为93%-105%。方法对照结果亦表明,本方法简便、快速、准确  相似文献   

9.
析相光度法测定铁(Ⅲ)的研究   总被引:2,自引:0,他引:2  
本研究了铁(Ⅲ)-PEG(聚乙二醇-2000)-铬锖R-Na2SO4体系的上光度法并应用于测定Fe(Ⅲ)。最适酸并为4.5 ̄6.5(NaAc-HAc)缓冲溶液,其络合物的最大吸收位于560nm,表观摩尔吸光系数为5.36×10^4L·mol^-1·cm^-1,Fe(Ⅲ)浓度在0 ̄4μg范围内服从比尔定律,铁与铬菁R形成组成为1:2的稳定络合物。该方法用于蔡叶中铁的测定,获得了满意的结果。  相似文献   

10.
硫氰酸铵树脂相分光光度法同时测定天然水中微量铁和钴   总被引:4,自引:0,他引:4  
研究了在Tween-80存在的酸性介质中,Fe(Ⅲ)和Co(Ⅱ)与SCN^-形成稳定的有色络阴离子与阴树脂交换吸附,有色络合物富集显色于树脂组上,进行树脂组分光光度集显色于树脂相上,进行树脂相分光光度法同时测定铁和钴的实验条件,Fe(Ⅲ)和Co(Ⅱ)树脂具有色络合物最大吸收波长λmax分别为490nm和630nm,摩尔吸光系数,ε为2.4×10^5L.mol^-1.cm^-1和2.1×10^5L.  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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