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1.
中草药中微量锗和钼的同时测定   总被引:1,自引:0,他引:1  
本文采用硅藻土 TBP反相萃取层析 分光光度法同时测定了中草药中的锗和钼的含量 ,获得了锗、钼含量较高的中草药。中草药样品经处理、消化后 ,用盐酸将试样中HCl浓度调至 6mol·L-1,加入以负载有磷酸三丁酯 (TBP)的烷基化硅藻土做固定相的层析柱。用 4mol·L-1盐酸以 0 5mL·min-1的流速洗脱锗 ,苯基荧光酮 CTMAB分光光度法测定锗 ,Ge PF CTMAB络合物的λmax=5 10nm ,摩尔吸收系数ε510 =1 6 7× 10 -5L·mol-1·cm-1。用 0 5mol·L-1盐酸以 0 5mL·min-1的流速洗脱钼 ,苯基荧光酮 CTMAB分光光度法测定钼 ,Mo PF CTMAB络合物的λmax=5 2 5nm ,摩尔吸光系数ε52 5=1 16× 10 -5L·mol-1·cm-1。该方法可对样品中的锗和钼同时测定 ,简便易行 ,具有较高的灵敏度 ,而且能有效地避免共存离子的干扰。  相似文献   

2.
二甲苯胺蓝褪色光度法测定水中痕量铬   总被引:4,自引:0,他引:4  
研究了在酸性介质中铬(Ⅵ)催化溴酸钾氧化二甲苯胺蓝褪色的最佳条件.本法λmax=515nm,表观摩尔吸光系数为2.5×104L·mol-1·cm-1,线性范围为0-26μg/25mL.用于水样中痕量铬的测定,结果令人满意.  相似文献   

3.
用分光光度法研究了亮氨酸与四氯对苯醌的荷移反应.实验结果表明,在硼砂缓冲溶液中,两者于60℃水浴中恒温50min即可形成稳定的荷移络合物,其λmax=350nm,络合物组成比为1:1,表观摩尔吸光系数ε=2×104 L·mol-1·cm-1,浓度在0.16-8μg/mL,范围内符合比耳定律,回收率在99.6%-101.0%之间,相对标准偏差在0.6%以内.  相似文献   

4.
在弱碱性介质中,乳化剂-OP存在下,羟基萘酚蓝(HNB)和钙生成蓝色2:1络合物,λmax=650nm,ε=1.86×104L·mol-1·cm-1,钙含量在0-40μg/25mL内符合比尔定律,本方法用于烟叶中钙的测定,结果令人满意.  相似文献   

5.
在pH=7.0 NH4Ac-HAc缓冲介质中,镁与苦氨酸偶氮-H-酸(PHA)生成1:2蓝紫色络合物,λmax=632nm,ε=1.2×104L·mol-1·cm-1,镁的含量在1.0-80μg/50mL内符合比耳定律,本方法用于烟草样品中镁的测定,结果令人满意.  相似文献   

6.
缬氨酸的荷移分光光度法测定   总被引:1,自引:1,他引:0  
研究了缬氨酸与四氯对苯醌(TCBQ)的荷移反应,确立了荷移反应的最佳条件。实验表明,在水溶液中,两者在50℃水浴中恒温70min,即可形成2∶1型的稳定络合物,其最大吸收波长λmax=350nm,表观摩尔吸光系数ε=4.7×104L·mol-1·cm-1,在0—6.7μg/mL范围内符合比耳定律,方法的相对标准偏差小于1.2%。方法对样品含量测定,结果与文献方法一致。  相似文献   

7.
李刚  徐刚  董文丽 《光谱实验室》2007,24(2):265-267
Cr(Ⅵ)与二苯卡巴腙的快速显色反应,生成一种紫红色配合物,其表观摩尔吸收系数为6.7×104L·mol-1·cm-1,有色合物λmax=545nm,铬在0.01-2.5μg/mL符合比耳定律.据此建立了二苯卡巴腙分光光度法测定水和钢中Cr(Ⅵ)方法,该方法选择性好,操作简单,快速准确,适宜于水样及钢中微量铬(Ⅵ)的检测.  相似文献   

8.
李省云 《光谱实验室》2006,23(3):606-608
研究了盐酸半胱氨酸与四氯对苯醌的荷移反应,确定了荷移反应的最佳条件.结果表明,在硼砂介质中,两者可形成1:1的稳定络合物,其λmax=354nm,表观摩尔吸光系数ε=8.7×103L·mol-1·cm-1,在2-18μg/mL的范围内符合比耳定律.本方法测定药物制剂含量与文献方法一致,回收率在99.83%-102.4%,相对标准偏差在1.9%以内.  相似文献   

9.
在弱酸性条件下,阿莫西林能与亚甲蓝(MB)反应生成易被1,2-二氯乙烷萃取的离子对缔合物,其最大吸收波长为λmax=657 nm。据此建立了测定阿莫西林的萃取分光光度法,药物浓度在0.4~6.8 mg.L-1范围内符合比尔定律,在最大吸收波长657 nm处表观摩尔吸光系数ε=5.0×104L.mol-1.cm-1,最低检出限为0.01 mg.L-1,回收率为97.5%~101.3%。实验表明该法可成功地用于药物制剂及尿样中阿莫西林含量的测定,结果令人满意。  相似文献   

10.
用分光光度法研究了甲硫氨酸与2,3-二氯-5,6-二氰-1.4-苯醌(DDBQ)的荷移反应.实验表明,在pH=9.0三酸缓冲溶液中,在50℃水浴中加热30min,两者可形成稳定的1:1型的荷移络合物.此络合物的λmax343nm,表观摩尔吸光系数ε=1.4×104L·mol-1·cm-1,在0.4-15.0μg/mL范围内符合比耳定律,回收率在98.24%-101.1%,相对标准偏差为0.89%-0.95%.  相似文献   

11.
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   

12.
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   

13.
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   

14.
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   

15.
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   

16.
17.
A transient suppression method for piezoelectric ceramic transducer is presented. By adding some special pedestal pulses to the original transmitted signal, the transient effects in the output of the transducer can be just precisely transmission by use of a narrowband transducer. canceled, thereby achieving the broadband The experimental results show that the transient responses of the sinusoid pulses and coded signals are suppressed successfully and the acoustic waveforms radiated into the surrounding water are improved significantly.  相似文献   

18.
We experimentally demonstrate amplitude squeezed soliton utilizing intensity-dependent self-phase modulation in an asymmetric Sagnac interferometer.The system.whose components are connected via ferrule connector/physical connection(FC/PC)fiber connectors,constitutes all-fiber configuration to generate squeezed soliton.Soliton amplitude reduction measured by homodyne detection is near 4.0 dB below the shot-noise level.Optimal squeezing fields in both simple and compact all-fiber configuration are obtained.  相似文献   

19.
The(2 1)-dimensional nonlinear Schr(o)dinger(NLS)equation with spatially inhomogeneous nonlinearities is investigated,which describes propagation of light in(2 1)-dimensional nonlinear optical media with inhomogeneous nonlinearities.New types of optical modes and nonlinear effects in optical media are presented numerically.The results reveal that the regular split of beam can be obtained in (2 1)-dimensional nonlinear optical media with inhomogeneous nonlinearities,by adjusting the guiding parameter.Furthermore,the stability of beam regular split is discussed numerically,and the results reveal that the beam regular split is stable to the finite initial perturbations.  相似文献   

20.
In the real-world application of face recognition system, owing to the difficulties of collecting samples or storage space of systems, only one sample image per person is stored in the system, which is so-called one sample per person problem. Moreover, pose and illumination have impact on recognition performance. We propose a novel pose and illumination robust algorithm for face recognition with a single training image per person to solve the above limitations. Experimental results show that the proposed algorithm is an efficient and practical approach for face recognition.  相似文献   

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