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1.
在pH 5.0 的NaAc-HAc缓冲溶液中, PVA 存在时, 锡和邻苯二酚紫(PV) 与罗丹明B(RhB) 生成离子缔合物, 其组成为Sn∶PV∶RhB= 1∶2∶4。缔合物最大吸收波长为560 nm , 表观摩尔吸光系数ε=1.18×105 L·m ol- 1 ·cm - 1 。锡量在0~15 μg/25m L范围内符合比耳定律。拟定方法已用于某些样品中微量锡的测定, 结果满意。  相似文献   

2.
固相分光光度法测定食品中痕量锡   总被引:9,自引:0,他引:9  
本文研究了以邻苯二酚紫为显色剂固相分光光度法测定痕量锡的新方法 ,在 pH =2 5条件下直接在树脂相于最大吸收波长 5 70nm处测量 ,锡含量在 0~ 15 0 μg·L- 1 范围内符合比尔定律 ,表观摩尔吸光系数可达 7 2× 10 6L·mol- 1 ·cm- 1 ,该法可应用于食品中痕量锡的测定  相似文献   

3.
在 p H1.6的氯乙酸缓冲介质中 ,溴化十六烷基三甲基铵存在下 ,Sn( )与溴邻苯三酚红及磺基水杨酸形成 ( 1+2 +1)的胶束混配络合物。络合物的最大吸收波长为 540 nm,表观摩尔吸光系数为 8.9× 10 4 L·mol-1·cm-1。Sn( )浓度在 0— 0 .6mg/ L范围内符合比耳定律。方法的选择性及稳定性都比无磺基水杨酸时好 ,适用于罐头盒中微量锡的测定 ,结果令人满意。  相似文献   

4.
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   

5.
用钨盐涂覆石墨管,大幅度提高测定血清中锡的灵敏度和稳定性。选用氨和钼酸盐混合基体改进剂,消除基体干扰。方法简便、快速、灵敏度和精密度高。特征浓度2.73×10-3μg·ml-1/1%。回收率95.75~106.16%。RSD2.63~7.34%。  相似文献   

6.
研究了新试剂5-(偶氮苯)-8-(4-硝基-1-重氮苯)-氨基喹啉(PANPAQ)与铜的显色反应,在弱碱性介质中,吐温-80存在下,PANPAQ与Cu(Ⅱ)反应生成2:1紫色络合物,λmax=615nm,ε=5.19×10^4L·mol^-1·cm^-1,铜含量在0-15μg/25mL内符合比耳定律,方法用于生物样品中铜的测定,结果满意。  相似文献   

7.
本文研究了在溴化十六烷基三甲胺存在下,苯基荧光酮与铁的显色反应。试验结果表明,显色的适宜酸度为pH等于7.3至10.5,配合物的摩尔吸光系数为1.09×105L·mol-1·cm-1,铁量在0-6μg·25mL-1范围内符合比耳定律。用于试样中铁的测定,灵敏度高,且简便可靠。  相似文献   

8.
本文研究了新显色剂4,4'-二(2,6-二溴-4-硝基苯基重氮氨基)联苯与Hg(Ⅱ)的显色反应,在表面活性剂Triton X-100的存在下,于pH8.8的Na2B4O7-HCl缓冲溶液中,试剂与Hg(Ⅱ)形成2:2橙红色配合物,其最大吸收峰位于490nm,表观摩尔吸光系数为7.62×10^4L·mol^-1·cm^-1。Hg(Ⅱ)量在0-12μg/25mL范围内符合比耳定律。方法用于废水中微量Hg(Ⅱ)的测定,结果满意。  相似文献   

9.
系统研究邻硝基苯基荧光酮与钛的显色反应,试验多种表面活性剂对体系的作用及相应的光度性质,从而确定Ti(Ⅳ)-ONPF-Tween-40为较佳体系,在0.084-0.15mol/L HCl介质中形成紫红色配合物,其波长在530nm处的表观摩尔吸光系数ε为1.79×10^5L·mol^-1·cm^-1,配合物组成中Ti:ONPF=1:4,钛浓度在0-1.2μg/10mL范围内服从比耳定律。应用于直接测定硅铁合金中钛,结果满意。  相似文献   

10.
在pH=4.5HAc-NaAc缓冲介质中,吐温-80存在下,2-(4安替比林偶氮)-5-二甲氨基苯胺(ADA)与铜生成2:1红色络合物,λmax=520nm,ε=5.24×10^4L·mol^-1·cm^-1。铜含量在0-20μg/25mL内符合比耳定律,方法用于食品中铜的测定,结果满意。  相似文献   

11.
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   

12.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
For breaking through the sensitivity limitation of conventional surface plasmon resonance (SPR) biosensors, novel highly sensitive SPR biosensors with Au nanoparticles and nanogratings enhancement have been proposed recently.But in practice, these structures have obvious disadvantages.In this study, a nanohole based sensitivity enhancement SPR biosensor is proposed and the influence of different structural parameters on the performance is investigated by using rigorous coupled wave analysis (RCWA).Electromagnetic field distributions around the nanohole are also given out to directly explain the performance difference for various structural parameters.The results indicate that significant sensitivity increase is associated with localized surface plasmons (LSPs) excitation mediated by nanoholes.Except to outcome the weakness of other LSP based biosensors, larger resonance angle shift, reflectance amplitude, and sharper SPR curves' width are obtained simultaneously under optimized structural parameters.  相似文献   

19.
Novel polymer distributed feedback(DFB)gratings are fabricated based on photopolymerization to reduce lasing threshold of polymer lasers.A photopolymer formulation sensitive to 355-nm ultraviolet(UV)light is proposed for the fabrication of polymer gratings and it can be used to form polymer films by spin-coating process.A very low surface-relief depth ranging from 12.5 to about 1.0 nm has been demonstrated with a refractive-index modulation of about 0.012.The experimental results indicate that such polymer gratings have promising potentials for the fabrication of low-order DFB organic semiconductor lasers.  相似文献   

20.
We propose a novel methodology based on the projector-camera (ProCam) system to address the photometric compensation issue for the projection display on the patterned screen.The patterned screen is treated as the combination of a perfect white screen and a color modulator.The perfect white screen is used to automatically and accurately characterize the ProCam system offline using the polynomial model,and the parameters of the color modulator can be efficiently recovered by employing only two gray images based on the linear reflectance model.The experimental results show that the color artifacts of the display image can be greatly improved with this methodology,which demonstrates its feasibility and validity in the photometric compensation.  相似文献   

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