2-(2-喹啉偶氮)-1,5-苯二酚固相萃取光度法测定银的研究

研究了新试剂 2 (2 喹啉偶氮 ) 1,5 苯二酚 (QADHB)与银的显色反应 ,在 pH =5 0柠檬酸 氢氧化钠 (内含 0 0 1mol·L- 1 Na2 EDTA)缓冲介质中 ,十二烷基磺酸钠 (SDS)存在下 ,QADHB与银反应生成摩尔比为 2∶1的稳定络合物 ,该络合物可被WatersSep ParkC1 8固相萃取小柱萃取富集。富集在小柱上的络合物用乙醇 (含 1%乙酸 )洗脱后 ,在乙醇介质中 ,其吸收光谱的λmax=5 5 0nm ,ε=6 99× 10 4 L·mol- 1 ·cm- 1 。银含量在 0～ 1 2 μg·mL- 1 范围内符合比尔定律。方法用于环境水样中痕量银的测定 ,结果令人满意     

过硫酸钾-甲基紫-银(Ⅰ)催化体系动力学光度法测定痕量银

在醋酸 -醋酸钠缓冲介质中 ,有活化剂邻二氮菲存在时 ,Ag( )对过硫酸钾氧化甲基紫褪色反应有催化作用 ,建立了测定痕量银的新催化光度法。实验优化了反应条件 ,线性范围为 4 .0— 80 μg/ L,检出限为1.5 5× 10 -9g/ m L,相对标准偏差 1.2 % (n=11)。催化反应表观活化能 Ea=4 4.31KJ·mol-1,表观速率常数 k=7.2 7× 10 -4s-1。表观摩尔吸光系数 ε=7.30× 10 5L·mol-1· cm-1。用于洗像废液中银的测定 ,结果令人满意     

非线性光散射、振荡与谐波产生

单壁碳纳米管表面增强喇曼散射的新方法=New technique in SERS study on single wailed carbon nanotubes[刊,中]/方炎(首都师范大学北京市纳米光电子学重点实验室.北京(100037)),欧阳雨∥光电子·激光.—2004,15(6).—731-733 依据碳纳米管独特的力学性能,在银表面直接研磨单壁碳纳米管(SWCNTs),在形成纳米级粗糙银表面的同时,SWCNTs管也吸附在银表面上,在银表面粗糙程度和SWCNTs厚度适中的区域得到了高质量的表面增强喇曼散射(SERS)谱。理论分析和实验结果表明,该方法是正确可行的。图2表1参10(于晓光)     

摄影光学 感光材料与性能测试

TB84 2006043405超声场下不同形貌银胶体的制备与表征=Preparation andcharacterization of different morphological silver colloids byultrasonic field[刊,中]/程敬泉(天津大学化工学院.天津(300072)) ,姚素薇…∥天津大学学报.—2006 ,39(1) .—34-38为了研究制备工艺条件对不同形貌银胶体稳定性的影响,在超声场作用下,以AgNO3为前驱物,聚乙烯吡咯烷酮为保护剂,KBH4和N2H4·H2O分别为还原剂,制备了稳定的银胶体,并利用透射电镜和分光光度技术对制备的银胶体进行了表征。结果表明,超声场分布、超声作用时间、超声功率和还原剂种类…     

紫外分光光度法同时测定柠檬黄和日落黄

采用紫外分光光度法同时对饮料中柠檬黄、日落黄两种食用合成色素进行测定,确定了各色素的最大吸收波长λmax,及其最大吸收波长处的吸收系数a和摩尔吸收系数ε.结果表明:柠檬黄在λmax=426nm处的吸收系数为a=33.45 L·g-1,摩尔吸收系数为ε=1.79×104L·mol-1·cm-1.日落黄在λ=481nm处的吸收系数为a=34.00 L·g-1·cm-1,摩尔吸收系数为ε=1.54×104L·mol-1.cm-1.测定饮料中柠檬黄、日落黄含量分别为0.0067mg/mL,和0.0033mg/mL,相对标准偏差(RSD)分别为0.148%、1.026%,测定了两种色素在奥地利饮料中的回收率分别为:92.35%、96.77%.该方法操作简便,同时准确度高,精密度好.     

表面等离子体共振技术研究肝素对高迁移率族蛋白1与晚期糖基化终产物受体亲合力的影响

测定肝素与高迁移率族蛋1(HMGB1),及其与晚期糖基化终产物受体(RAGE)的亲和力,探讨肝素对HMGB1/RAGE亲和力的影响.用表面等离子体共振技术,实时分析肝素与HMGB1,HMGB1与RAGE的亲和常数,利用其binding analysis分析肝素对HMGB1/RAGE配受体结合的影响.肝素与HMGB1的动力学速率常数ka=1.78×105 L·(mol·s)-1,kd=8.02×10-4·s-1,亲和常数KA=2.22×108L·mol-1,KD=4.5×10-9 mol·L-1;HMGB1与RAGE的动力学常数ka=1.85×103L·(mol·s)-1,kd=1.81×10-4·s-1,亲和常数KA=1.02×107L·mol-1,KD=9.77×10-8mol·L-1.肝素与RAGE的亲和力极低.当浓度分别为50,100,1 000,10 000 U·L-1的肝素与HMGBl混合后,后者与RAGE的亲和力下降.上述不同浓度的肝素对HMGB1/RAGE亲和力的影响没有显著差异.结果表明,肝素可与HMGB1结合并影响后者与RAGE的亲和力,该作用并不与肝素浓度呈正相关.     

胸腺嘧啶在改进银溶胶溶液中的表面增强拉曼散射光谱信号与浓度的定量关系

尝试使用高分子材料作为银溶胶的稳定剂,以吡啶作为内标化合物研究胸腺嘧啶浓度与其SERS信号强度的关系。在胸腺嘧啶的浓度为2×10-4～1×10-3 mol·L-1的范围内,谱峰强度之比与胸腺嘧啶的浓度之间呈现良好的线性关系,线性回归方程为y=3.143x+0.348 7, 线性相关系数R2=0.975 4。     

不同银含量的Pd-Ag复合膜微结构光栅光纤 氢气传感特性

研究了不同钯银合金原子比例复合膜对微结构光纤光栅氢气传感特性的影响.使用飞秒激光在布拉格光栅光纤包层加工螺旋微结构,将磁控溅射方法制备的不同钯银原子比例的合金膜镀在螺旋微结构表面,研制优化钯银合金比例的新型微结构布拉格光栅光纤氢气传感器.采用扫描电子显微镜和能谱仪对Pd-Ag薄膜进行表征和分析,对三种不同钯银原子含量(Pd∶Ag=2∶1,4∶1,6∶1)的微结构布拉格光栅光纤探头进行氢气传感测试.在室温条件下,钯银原子比例为4∶1的微结构探头具有最佳的氢气传感性能,钯银原子比例为2∶1的微结构探头响应速度最快,但是灵敏度最低.在4%氢气浓度下,螺旋微结构传感器的漂移量达到107pm,对比同类型布拉格光栅光纤氢气传感器,具有更高的灵敏度和更快响应速度.     

银纳米微粒荧光猝灭法测定水中痕量ClO2

在pH 9.1的NH4Cl-NH3·H2O缓冲溶液中,银纳米微粒在470 nm处产生一个荧光峰;它能被ClO2氧化导致体系的荧光发生猝灭.ClO2浓度在0.001 1～0.185μg·mL-1范围内与荧光猝灭强度成良好的线性关系,检测限为0.004 7μg·mL-1 ClO2.据此建立了测定ClO2的荧光分析新方法,用于饮用水中ClO2的测定,结果满意.     

基于未修饰银纳米粒子光度法测定卡托普利

研究建立了一种简单、快速、高灵敏测定药物卡托普利的新方法。该方法基于卡托普利诱导未修饰的银纳米粒子的快速团聚,从而使银纳米溶胶从亮黄色变为红色,在395 nm处的吸光度呈线性降低。探讨了银纳米粒子的团聚机理。在优化条件下,该方法测定卡托普利的线性范围为1～35 μg·mL-1,检出限为0.7 μg·mL-1。应用于卡托普利药片含量的测定,获得了满意结果。     

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.     

Resonance scattering of canonical elastic shells in absorbing fluid medium

Resonance scattering of elastic spherical shell and cylindrical shell while the surrounding fluid medium has absorption is studied. The normal mode solution derived using exact elastic theory and the separation of variables is still applicable. However, the scattering form function has to be modified for the absorbing medium, otherwise the unreasonable result would be obtained. The backscattering form function in the absorbing medium is redefined, and the form function of elastic spherical and cylindrical shell with vacuum or solid matter filled is calculated in various absorption conditions. The results show that the absorption of surrounding fluid leads to notable attenuation of the coincidence resonances in the mid-frequency, but it has a little influence on the low-frequency resonance scattering induced by the filler inside the shell.     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Influences of SiO2 protective layers and annealing on the laser-induced damage threshold of Ta2O5 films

Ta2O5 films are prepared on BK7 substrates with conventional electron beam evaporation deposition.The effects of SiO2 protective layers and annealing on the laser-induced damage threshold (LIDT) of the films are investigated.The results show that SiO2 protective layers exert little influence on the electric field intensity(EFI)distribution,microstructure and microdefect density but increase the absorption slightly.Annealing iS effective on decreasing the microdefect density and the absorption of the films.Both SiO2 protective layers and annealing are beneficial to the damage resistance of the films and the latter is more effective to improve the LIDT.Moreover,the maximal LIDT of Ta2O5 films is achieved by the combination of SiO2 protective layers and annealing.     

A stereo matching algorithm using multi-peak candidate matches and geometric constraints

Gray cross correlation matching technique is adopted to extract candidate matches with gray cross correla- tion coefficients less than some certain range of maximal correlation coefficient called multi-peak candidate matches. Multi-peak candidates are extracted corresponding to three closest feature points at first. The corresponding multi-peak candidate matches are used to construct the model polygon. Correspondence is determined based on the local geometric relations between the three feature points and the multi-peak candidates. The disparity test and the global consistency checkout are applied to eliminate the remaining ambiguous matches that are not removed by the local geometric relational test. Experimental results show that the proposed algorithm is feasible and accurate.