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1.
王明  张一心 《光谱实验室》1999,16(4):465-467
在pH7.0混合磷酸盐介质中,SO3^2-使I3^-与CTMAB生成离子缔合物CTMA^+,I3^-而褪色,从而建立了测定SO3^2-的新间接紫外光度法,测定波长为365nm,SO3^2-浓度在0-25μg/25mL内服从比耳定律,表观摩耳吸光系数为ε=6.04×10^4L·mol^-1·cm^-1,可用于食品中微量SO3^2-的测定,其结果满意。  相似文献   

2.
研究新合成的水溶性光度试剂N-壬基-N‘-(氨基对苯磺酸钠)硫脲与钯的显色反应。结果表明,在pH5.8-6.6的HAc-NaAc缓冲体系中,Pd^2+与NTP形成1:4的黄色水溶性配合后物,CTMAB对反应有明显的增敏作用,配合物的最大吸收波长位于297.6nm,表面摩尔吸光系数ε297.6=1.27×10^5L.mol^-1cm^-1,钯含量在2-11.2μg/25mL范围内服从比尔定律,50种  相似文献   

3.
二碘苯基荧光酮与钨的显色反应及其在钢铁分析中的应用   总被引:1,自引:1,他引:0  
本文研究了新试剂二碘苯基荧光酮(DIPF)与钨的显色反应,在硫磷混合酸介质中,CPB存在下,二碘苯基荧光酮(DIPF)与钨生成3:1稳定红色络合物,λmax=510nm、ε=2.52×10^5L.mol^-1.cm^-1,钨含量在0-10μg/25mL 内符合比耳定律,方法用于钢样中钨的测定,结果令人满意。  相似文献   

4.
褪色光度法测定微量硫化物的研究   总被引:2,自引:0,他引:2  
根据S^2-对4-(对磺酸基苯基)-卟啉(TSPP)与铅显色反应的褪色干扰作用,建立了一种测定S^2-的新方法,该方法对S^2-的检出限为10μg/L,选择性较好,用于含硫废水中痕量S^2-的测定,结果令人满意。  相似文献   

5.
次甲基绿—溴酸钾体系催化光度法测痕量钒(V)的研究   总被引:6,自引:0,他引:6  
本文基于在抗坏血酸存在下,痕量钒(V)对溴酸钾氧化次甲基绿褪色的新指示反应,建立了一个催化动力学光度法测痕量钒(V)的新方法。线性范围为0-0.12μg/25mL和0.12-0.20μg/25mL,方法检出限为3.4×10^-10g/mL。用于人发、水样中痕量钒(V)的测定,结果满意。  相似文献   

6.
铝-氟-DSPCF分光光度法测定地下水中铝   总被引:1,自引:1,他引:0  
本文研究了铝-氟-1,5-二(2-羟基-5-磺基苯基)-3-氰基甲(DSPCF)的显色反应。在硼酸-硼砂介质中,显色反应灵敏,最大吸收波长为610nm,配合物的表现摩尔吸光系数5.0×104,铝含量在0-15μg/25mL符合比尔定律。该法用于地下水中微量铝的测定获得了满意结果。  相似文献   

7.
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   

8.
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   

9.
解文秀 《光谱实验室》2000,17(4):477-479
在酸性介质中,痕量钼(Ⅵ)对过氧化氢氧化罗丹明B褪色反应有较强的催化作用,本文研究了反应的最佳条件,建立了测定痕量钼的新方法,方法最低检出限为5.0*10^-10g/mLMo(Ⅵ)检测线性范围为0-1.0μg/25mLMo(Ⅵ),用于水样及食品中Mo(Ⅵ)的测定,获得满意结果。  相似文献   

10.
使用离子速度成像(Ion Imaging-Velocity Mapping)技术来测量光电子能谱及其角分布,对碘原子在277nm附近的(2+1)多光子电离过程I^*(^2P1/2)→I′(^1D2)6p[1]1/2→I^+和I(2P3/2)→I′(^3P0)6p[1]1/2→I^+进行了研究。与文献报道的结果相比,分辨率要好5倍,相对能量分辨率达到6%。还讨论了速度成像方法中速度分布校正和重构三维  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.
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   

13.
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   

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.
16.
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   

17.
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   

18.
The key to the restoration of rotational motion blurred image is how to restore the image under a low cost and to correct the irreversibility of the degradation function matrix.Based on the special qualities of degradation function matrix and precise deduction in space-domain, we present a new approach using gradient-loading for restoration of rotational blurred image.By easily adding a gradient operator, the irreversibility of the original matrix is corrected and can be applied for inverse filtering then.Gradientloading is the optimized approach which combines the advantages of both the approaches using constrained least square filtering and traditional diagonal-loading.Compared with the approach using least square filtering, its peak signal-to-noise ratio (PSNR) is improved from 3.18 to 6.46dB, while the computing time is reduced to 1/2-1/3.Experimental results demonstrate the effectiveness, noise-resistibility, robustness, and low complexity of this approach, which make it more suitable for real-time environment.  相似文献   

19.
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   

20.
We propose an all-optical logic device made of a bent tapered Y-junction waveguide with a Kerr-type nonlinear interface. It could provide an AND gate, OR gate, and exclusive-OR (XOR) gate. We could obtain different transmission results by adjusting the bending angle. The numerical simulation results show that the device functions as AND, OR, and XOR gates.  相似文献   

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