地钱中总黄酮含量的测定

采用改进的铝盐显色分光光度法 ,在 5 2 5 nm波长下 ,Na NO2 - Al Cl3 - Na OH为显色剂 ,常温显色 ,15 min内测定地钱黄酮提取物中总黄酮的含量。在 4 0— 4 0 0 μg/ m L范围内线性关系良好 ,回归方程为 A=0 .0 30 0 C- 0 .0 15 3,RSD=0 .16 % ,相关系数为 0 .9997,加标回收率在 97.6 1%— 10 1.5 9%范围内。本法用于地钱中总黄酮含量的测定 ,方法准确、可靠 ,结果令人满意     

鱿鱼丝中乳糖含量的测定

以苯酚、氢氧化钠、苦味酸和亚硫酸氢钠混合溶液为显色剂 ,分光光度法测定鱿鱼丝中乳糖含量。乳糖在 4— 80 μg/m L范围内与吸光度呈良好的线性关系 ,检出限为 1 .0 μg/m L,回收率为 99.8%— 1 0 0 .0 %。该法简便快捷 ,结果令人满意     

紫外分光光度法测定维生素B_6

本文建立了以 0 .0 35 mol/ L HAc(醋酸 )为介质 ,采用紫外分光光度法测定维生素 B6的新方法。该方法体系简单 ,操作方便、快速、灵敏 ,其表观摩尔吸光系数ε为 9.37× 10 4 L· mol-1· cm-1。线性范围为0 .61— 4 0 .10μg/ m L。用于 VB6片剂和针剂测定 ,回收率为 10 0 .82 %— 10 1.90 %     

分光光度法测定蒸馏酒及配制酒中杂醇油

研究了分光光度法测定蒸馏酒及配制酒中杂醇油的实验条件 ,提高了方法的稳定性、精密度和准确度。杂醇油浓度在 0— 0 .0 4 0 mg/ m L范围内线性关系良好 ,检出限为 2 μg/ m L,相对标准偏差在 1 .5 8%—3.5 7%之间 ,样品加标回收率在 94 .0 %— 1 0 4 .0 %之间 ,方法简单、快速 ,用于酒样中杂醇油的测定 ,结果令人满意。     

分光光度法测定发酵液中果糖的含量

针对微生物转化发酵液体系的特征 ,用分光光度法测定其中果糖的含量。校准曲线回归方程为 y=2 6 .2 3x 0 .0 0 7,相关系数为 0 .9991 ;1 0倍量葡萄糖和 1 0倍量甘露醇的存在对果糖测定基本无干扰 ;发酵液中果糖测定的加标回收率为 99.1 %— 99.8%。     

黑龙江膜荚黄芪多糖及微量元素Fe、Zn、Cu和Mn的测定

采用水提醇沉法制备黄芪多糖提取物,苯酚-硫酸分光光度法测定多糖的含量,在0.00-0.14mg/mL线性范围内具有良好的线性关系,回收率在94.81%-103.50%.测定黄芪多糖含量为4.3%.采用校准曲线法,用空气-乙炔火焰原子吸收光谱法测定样品中Fe、Zn、Cu和Mn的含量,膜荚黄芪中微量元素含量较高.     

薄层层析-分光光度法测定南瓜中β-胡萝卜素

石油醚∶丙酮 (7∶ 3)混合液作提取剂 ,薄层层析 -分光光度法测定了南瓜中 β-胡萝卜素的含量 ,对该法的精密度、准确性进行了探讨。在 β-胡萝卜素的最大吸收波长 4 5 0 nm下 ,回归方程为 A=0 .0 2 4 0 5 6 C-0 .0 0 2 4 6 4,r=0 .998。测定结果的相对标准偏差在 2 .0 1%— 4 .5 2 %之间 ,回收率在 94 .5 0 %— 97.2 0 %之间 ,检出限为 0 .5 μg     

胶束增溶光度法测定土豆中微量铝

采用 Al( ) - CAS- CTMAB- OP胶束增溶分光光度法测定了土豆中的铝。实验表明 ,在 p H=6 .5的HAc- Na Ac缓冲溶液中 ,λmax=6 2 0 nm处 ,Al3 在 0— 0 .2 4 μg/ m L范围遵守朗伯 -比耳定律 ,回归方程、相关系数、回收率和 RSD分别为 :A=4 .773C- 0 .0 1 3、r=0 .9995 (n=4 )、98.8%— 1 0 2 %和 0 .5 3%。不同产地土豆样品中 Al含量为 :1号样品 1 6 8.8μg/ g,2号样品 1 6 7.0 μg/ g     

分光光度法测定镧汞齐中的镧

以偶氮胂 为显色剂 ,氯乙酸 -氢氧化钠为缓冲溶液 ,用分光光度法直接测定镧汞齐中镧含量。最佳的显色酸度为 p H2 .8— 3.0 ,最佳测定波长为 6 6 0 nm。镧含量在 0— 75 μg/ 2 5 m L范围内吸光度符合比耳定律 ,线性回归方程为 A=- 0 .0 2 4 8+0 .0 132 C,相关系数 r=0 .9992 ,配合物的摩尔吸光系数 ε为 4 .2 8×10 4L· mol-1· cm-1,回收率为 97.3%— 10 3.6 %。本法显色稳定性好 ,灵敏度高 ,操作简便 ,快速     

分光光度法测定沙棘叶多糖含量

经苯酚-硫酸显色,用分光光度法测定沙棘叶多糖含量。测定波长490nm,葡萄糖含量在10.0—71.0μg/mL范围内与吸光度呈良好的线性关系,r=0.9981,多糖换算因子f为3.271。测得不同月份同一片植株沙棘叶多糖含量分别为:5月份3.39%,7月份3.94%,9月份4.42%,平均回收率为99.07%,RSD为3.22%。     

药材瓜蒌不同部位的红外光谱分析

采用傅立叶红外光谱和二阶导数谱分析方法,对药材瓜蒌不同部位(皮、瓤、子)的红外光谱进行分析.红外谱图显示,瓜蒌各部位均含糖及苷;瓜蒌皮和瓜蒌子中含黄酮及酯类成分;瓜蒌瓤和瓜蒌皮中含相当量的淀粉.二阶导数谱中,在1800～700 cm-1区域内,瓜蒌子的谱峰最简单,次之为瓜蒌瓤,全瓜蒌和瓜蒌皮的峰数较多,峰形和峰强比较相...     

傅里叶变换红外光谱法应用于中药砂仁真伪鉴别的研究

为了直接准确地鉴别砂仁及其伪品的真伪, 采用傅里叶变换红外光谱法直接测定砂仁及其伪品的红外光谱。结果阳春砂、绿壳砂、海南砂的红外光谱差别不大,而砂仁与其伪品红壳砂仁、海南假砂仁、华山姜及山姜的红外光谱吸收差别较大。对同一批次的不同样品进行了重复性试验,二阶导数傅里叶变换红外光谱正峰值的峰位一致率检验结果无显著性差异存在,说明可以采用FTIR法直接、快速、准确地对阳春砂、绿壳砂、海南砂与其伪品红壳砂仁、海南假砂仁、华山姜及山姜进行区别鉴定。     

火焰原子吸收光谱法测定小茴香中的铜、铁、锰和锌

样品在550℃灰化,用王水浸提。用火焰原子吸收法测定样品中的Fe、Cu、Zn、Mn的含量,并对其结果进行了分析。此法校准曲线性关系良好,回收率在94.70%—104.33%。测定结果表明,小茴香中的铁含量较高。     

桂皮和小茴香中砷、铅、镉和汞的测定

用电感耦合等离子体-原子发射光谱法(ICP-AES)对桂皮和小茴香中的有害元素砷、铅、镉和汞进行了定量测定.结果表明,该方法简便可靠,具有良好的精密度和准确度.本文为桂皮、小茴香的种植及入药等方面提供了一些有用的信息.     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

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.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

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.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

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.     

Sorting of bending magnets for the SSRF booster

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.     

Measurement of nonlinear coefficient of optical fiber based on small chirped soliton transmission

We measure the waveform and phase curves of short optical pulses before and after transmission over different lengths of fibers by use of the pulse analyzer with the frequency-resolved optical gating (FROG),and numerically simulate pulse evolution under the experimental conditions.The nonlinear coefficient of the fiber is given by comparing the experimental results with the numerical ones.Difference between the experiment and numerical simulation is analyzed.