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1.
为了更快速、简便、准确地同时测定多种抗生素混合物,采用同步荧光光谱结合径向基神经网络的方法,对3种氟喹诺酮类抗生素(乳酸环丙沙星、乳酸左氧氟沙星、盐酸左氧氟沙星)的同步荧光光谱进行研究。选择3组分浓度均为1.67ng/mL的混合溶液,测量其3维同步荧光光谱;分别测量39种不同浓度的混合溶液样本的同步荧光光谱;选取其中35种作为训练组,其余4种作为预测组,将训练组样本对应的光谱数据作为输入,建立和训练径向基神经网络;在发射波长与激发波长的差Δλ=194nm条件下,利用训练好的神经网络对预测组中各组分的浓度进行预测,得到3种组分浓度预测的平均相对误差分别达到3.59%,3.47%,3.09%。结果表明,当Δλ设定为194nm时,3种抗生素的同步荧光峰差异最为明显、区分度高,该方法能实现对3种抗生素混合物中各组分的同时测定。这为多种抗生素混合物同时测定提供了一种快速、简便、准确的方法。  相似文献   

2.
A new anthracene derivative of 9,10-bis(2,5-dimethyl-4-(naphthalen-2-yl)phenyl)-2,3-diphenylanthracene (BDNPA) was designed and synthesized as a non-doped blue emitter in organic light emitting diodes (OLEDs). BDNPA has highly rigid structure and thermal stability with decomposition temperature (corresponding to 5% weight loss) of 490 °C, because p-naphthyl xylene groups in 9,10-positions were highly twisted to anthracene core due to steric hindrance of xylene groups, and because the 2,3-diphenyl groups were also twisted about 45–49° to anthracene. OLEDs with BDNPA non-doped emitter showed high efficiency of 5.21 cd/A due to the carrier mobility with well-aligned π-stacking structure toward out-of-plane by the face-on orientation by grazing incidence X-ray diffraction.  相似文献   

3.
光电流光谱技术与原子荧光法联用测定激光波长   总被引:1,自引:0,他引:1  
王松岳 《中国激光》1992,19(6):473-475
激光波长仪可在一定精度内测定激光波长,但在激光光谱学和激光分离同位素的应用研究中,不能保证测得的波长已与原子的某一跃迁共振。而光电流光谱技术恰好具有及时地反映这种共振的性能,激光激发原子荧光法的应用又为复杂原子谱线的认定提供准确可靠的依据。我们联用这两种技术简便快速而又准确无误地分别测定了与铀、镧原子一些非精细结构高分辨谱线中某一成分共振的激光波长。  相似文献   

4.
目的:比较红光(630nm)和蓝光(415nm)联合治疗与单纯蓝光(415nm)治疗面部寻常型痤疮的临床疗效。方法:将61例面部寻常型痤疮患者随机分为红蓝光联合治疗组与单纯蓝光治疗组,分别进行8周治疗,于实验第2周、4周、6周、8周对疗效进行比较分析。结果:59例患者完成了实验,红蓝光联合治疗组对脓疱、结节/囊肿的疗效(皮损总数的减少率)较单纯蓝光治疗组好,而单纯蓝光治疗组对丘疹的疗效较好,所得结果均有统计学意义(P〈0.05)。8周治疗结束后,两组皮损总有效率无差异性(P〉0.05)。结论:红蓝光联合治疗及单纯蓝光治疗均对面部寻常型痤疮有一定的疗效,虽然二者总体疗效无差别,但对不同类型皮疹的疗效不同,且所得结果有统计学意义。  相似文献   

5.
基于STM的三维荧光导数光谱法检测食品中黄曲霉素   总被引:1,自引:1,他引:0  
基于支持张量机(STM)的三维荧光导数光谱定量分析方法,检测了食品中黄曲霉素。在计算三维荧光导数光谱时,将常规的、只适用于向量光谱数据的Savitzky-Golay方法扩展到由二阶张量描述的三维荧光光谱中。同时,应用了STM方法建立校正模型,对白酒和牛奶中的黄曲霉素进行了检测。在对白酒中的黄曲霉素检测中,复相关系数(CC)和预测误差均方根(RMSEP)分别为0.952 3和14.847 5,与常规的偏最小二乘(PLS)和支持向量机(SVM)方法相比,CC分别提高了2.40%和2.34%,RMSEP分别降低了8.92%和4.36%。在对牛奶中的黄曲霉素检测中,CC和RMSEP分别为0.996 5和5.448 9,与PLS和SVM的方法相比,RMSEP分别提高了0.40%和0.30%,RMSEP分别降低了18.31%和17.18%。检测结果表明,基于STM方法建立的校正模型要优于传统的SVM方法和PLS方法。  相似文献   

6.
The picosecond time-resolved fluorescence decaysI(t)and spectraI(lambda, t)for hematoporphyrin derivative (HPD) in a phosphate buffer saline aqueous solution at different concentrations (8.4 times 10^{-6}sim 8.4 times 10^{-3}M) are measured by a two-dimensional synchroscan streak camera with a mode-locked CW dye laser, and a new emission band (which we call theY-band) is found at high concentration. It is shown that the fluorescence decays composed of fast and slow components at high concentration are due to theY-band (120 ps lifetime) from head-to-tail aggregates including equilibrium dimer and stable dimer, and the usual band (3.6 ns lifetime) from monomer, respectively, and the latter band is dynamically quenched by the Förster type resonance energy transfer from the monomer to the aggregate. Furthermore, the measurement of static fluorescence spectra from human gastric cancers and the surrounding in vivo after HPD injection shows that a band corresponding to theY-band from the aggregate appears at only the cancerous cells.  相似文献   

7.
The determination of Luzhou-flavor liquor ages is carried out by three-dimensional fluorescence spectroscopy combined with non-negative matrix factorization (NMF). 37 samples of aged liquors with weighted ages of 15, 20 and 25 years were prepared by blending three Luzhou-flavor original base liquors with storage ages of 10, 20 and 30 years in different proportions. The fluorescence spectra of the samples were measured, and then factorized into basis matrix and coefficients matrix by multiplicative iterative NMF. The fluorescence spectra, reconstructed from the basis matrix, are similar to the original spectra. The coefficients matrix is taken as the input of support vector machine (SVM) to establish a prediction model for the determination of liquor ages. Compared with the principal component analysis, the prediction model based on SVM has a predicted accuracy better than 91.7%. This method can provide helps for the market supervision on the aged liquors.  相似文献   

8.
目的:建立控制能脉胶囊质量的方法.方法:用高效液相色谱法(HPLC).采用色谱柱Zorbax RP-C18柱(150mm×4.6mm,5μm):流动相:甲醇:水=75:25(v/v):流速:0.8mL/min:波长254nm:柱温:25℃.结果:通脉胶囊中葛根素和丹参酮分离良好,葛根素线性范围是22.5μg/mL至2.25μg/mL,r=0.9997.丹参酮线性范围为16.5μg/mL至165μg/mL,r=0.9998.结论;该方法准确可靠,可用于控制通脉胶囊的质量.  相似文献   

9.
为了测定混合色素溶液中胭脂红的浓度,采用归一化的方法对荧光光谱进行数据预处理,将处理后的光谱数据结合径向基神经网络,建立了对胭脂红含量的预测模型。结果表明,3维同步荧光光谱、普通3维荧光光谱预测结果的平均相对误差分别为2.86%,11.12%;对于混合色素溶液中单个色素浓度的测定,3维同步荧光光谱结合径向基神经网络效果较好。该研究为预测混合色素溶液中各色素浓度提供了帮助。  相似文献   

10.
目的:建立控制通脉胶囊质量的方法.方法:用高效液相色谱法(HPLC).采用色谱梓ZorbaxRP-C18柱(150mm×4.6mm,5μm);流动相:甲醇:水=75:25(v/v);流速:0.8mL/min;波长254nm;柱温:25℃.结果:通脉胶囊中葛根素和丹参酮分离良好.葛根索线性范围是22.5μg/mL-225μg/mL,r=0.9997.丹参酮线性范围为16.5tμg/mL-165μg/mL,r=0.9998.结论:该方法准确可靠,可用于控制通脉胶囊的质量.  相似文献   

11.
为实现鸭蛋蛋清中庆大霉素(GM)残留含量的快速测定与检测模型精度的提高,应用遗传算法(GA)筛选导数同步荧光光谱特征波长,用遗传-支持向量回归(GA-SVR)建立鸭蛋蛋清中GM残留含量的预测模型。首先分析了样本的三维同步荧光光谱和确定了本实验研究的波长差Δλ为120nm;然后利用sym5小波的2层分解对一阶导数同步荧光光谱进行去噪处理,并利用GA筛选出了14个荧光特征波长;最后利用GA优化了SVR的径向基核函数(RBF)参数(c,g,p),进而比较了GA-SVR、PLS和MLR 3种预测模型的预测能力,研究表明,以GA-SVR模型的预测能力最强,其预测集的决定系数(R2)和均方根误差(RMSEP)分别为0.983 0和1.149 4mg/L。实验结果表明,GA能有效筛选出鸭蛋蛋清中GM的荧光特征波长和提高GA-SVR模型预测精度。  相似文献   

12.
《Organic Electronics》2014,15(2):500-508
A novel blue emitting and electro-chromic conjugated copolymer based on 9,9′dioctylfluorene (F8) and spiro(fluorene-9,9′-xanthene) (SFX) has been prepared. Optical, photophysical and electrochemical characterizations are given for the synthesized polymer; poly[spirofluorene-co-9,9′dioctylfluorene] P(F8-SFX). Switching of the corresponding polymer between yellow and purple states is demonstrated, and blue emission with Commission Internationale de L’Eclairage (CIE) coordinate at (0.19, 0.15) is obtained from PLED device. The addition of a thin polymer interlayer ((F8)0.5–(TFB)0.5) is further investigated to maintain color purity. Furthermore, all polymer electrochromic device (ECD) based on P(F8-SFX) and poly(ethylene dioxythiophene) (PEDOT) was constructed. Spectroelectrochemistry and switching ability of the device were also investigated by UV–vis spectroscopy.  相似文献   

13.
A novel intermediate connector (IC) was formed which was composed of aluminum (Al, 3 nm)/1,4,5,8,9,11- hexaazatriphenylene-hexacarbonitrile (HAT-CN). The 3-nm-thick Al in the IC is certified to efficiently generate intrinsic charge carriers, and the HAT-CN is proved to work as the holes injection layer (HIL) for the corresponding electroluminescent (EL) unit simultaneously. This simply IC comprehensively takes advantage of the features of the HAT-CN so as to stack two single EL units without introducing extra material. In addition to a significant enhancement in luminance and current efficiency, a current efficiency (CE) of 10.2 cd/A and a luminance of 2 042 cd/m2 under the current density 20 mA/cm2 of this tandem organic light emitting device (TOLED) are yielded, which are notably almost the sum of that of the two single-unit devices.  相似文献   

14.
应用空心阴极灯激光激发荧光法,间接分辨开镍原子高激发态f~3D_2和f~1D_2产生的611.6178nm和611.6179nm重迭谱线,并测得其线宽分别为2.1GHz和2.6GHz。  相似文献   

15.
The determination of magnetic flux and electric charge using a coil and capacitor is subject to the uncertainty relation.  相似文献   

16.
Surface plasmon (SP) enhanced blue organic light emitting diodes (OLEDs) have been realized by using silver nanoclusters (SNCs) deposited using thermal evaporation technique. SNCs were found to have the surface plasmon resonance at wavelength 445 nm and were used with blue emitting layer BCzVBi. The optimized OLED (in terms of the size of SNCs and the distance between SNCs and emitting layer) were found to have the efficiency two times higher than reference OLED without SNCs. Internal quantum efficiency was calculated to be 24% for SP enhanced OLED owing to 96% fluorescence efficiency. Energy transfer between exciton and SPs with the separation distance have been studied experimentally and using 2D-FDTD simulation and surface–dipole energy transfer has been observed.  相似文献   

17.
A highly fluorescent an ionic fluorene derivative 1 was synthesized and its photophysical, electrochemical and electroluminescence characteristics were investigated. Deep blue emissions were observed for compound 1 in solid as well as in dilute solutions. The synthesized compound shows high fluorescence quantum yield around 77% indicates that compound 1 can perform its role as efficient ionic emitter in LEC devices. Light-emitting electrochemical cell (LEC) devices were fabricated incorporating compound 1 without (device I) and with (device II) ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM·PF6). Devices I and II exhibited blue electroluminescence maximum centered at 455 and 454 nm with CIE coordinates of (0.15, 0.21) and (0.16, 0.22), respectively. Maximum luminance and current efficiency of 1105 cd m−2 and 0.14 cd A−1 respectively, has achieved for device I while that of device II resulted in 1247 cd m−2 and 0.14 cd A−1 respectively.  相似文献   

18.
李雷  韩彩芹  刘莹  吴庆州  王涛 《光电子.激光》2020,31(12):1348-1354
三七在现代中成药市场作为原料有着巨大的消耗 量,根源是其具有重要的药物价值,因此对三七的 研究具有着现实意义。但是三七含有几十余种化学成分,是典型的多组分物质,普通二维荧 光光谱对其难 以进行定量分析。本文应用FLS920荧光光谱仪测量了22个不同浓度的三七粉水溶液样本的三维同步荧光 光谱,结合二阶校正算法以及分半信度法(Split half Method)、核一致诊断算法(Core Consistency Diagnostic) 等分析确定三七粉水溶液的平行因子模型组分数为3。第一组分荧光特征峰区间λEx=380 nm, λEm=465 nm;第二组分荧光特征峰区间λEx=465 nm,λEm=515 nm;第三组分荧光特征峰区间 λEx=330 nm,λEm =415 nm。其第三组分荧光可能是人参 皂苷Rg1的荧光表现。实验发现,对于多组 分物质应用三维同步荧光光谱法结合二阶校正算法进行分析,可以去除冗余干扰信息,简化 光谱分析难度,从全局视角表达三七的整体荧光特性,为天然药物的分析提供建议与帮助。  相似文献   

19.
A new multifunctional blue-emitting terfluorene derivative (TFDPA) featured with triphenylamine groups for hole-transportation and long alkyl chains for solution processability on the conjugation inert bridge centers was reported. TFDPA can give homogeneous thin film by solution process and exhibits high hole mobility (μh  10?3 cm2 V?1 s?1) and suitable HOMO for hole injection. Particularly, TFDPA performs efficient deep-blue emission with high quantum yield (~100% in solution, 43% in thin film) and suitable triplet energy (ET = 2.28 eV), making solution-processed OLED devices of using TFDPA as blue emitter and as host for iridium-containing phosphorescent dopants feasible. The solution-processed nondoped blue OLED device gives saturated deep-blue electroluminescence [CIE = (0.17, 0.07)] with EQE of 2.7%. TFDPA-hosted electrophosphorescent devices performed with EQE of 6.5% for yellow [(Bt)2Ir(acac)], 9.3% of orange [Ir(2–phq)3], and 6.9% of red [(Mpq)2Ir(acac)], respectively. In addition, with careful control on the doping concentration of [(Bt)2Ir(acac)], a solution-processed fluorescence–phosphorescence hybrided two-color-based WOLED with EQE of 3.6% and CIE coordinate of (0.38, 0.33) was successfully achieved.  相似文献   

20.
不同产地小美牛肝菌的红外光谱聚类分析研究   总被引:2,自引:0,他引:2  
周在进  刘刚  任先培 《激光与红外》2009,39(11):1158-1162
同一种蕈菌子实体,由于外观形貌相似,凭传统外观形貌特征难以鉴别产地来源.用傅里叶变换红外光谱技术结合系统聚类分析了5个不同产地的63个野生小美牛肝菌子实体样本.结果表明,原始红外光谱在4000~400 cm-1总体特征相似,主要是由蛋白质、多糖等吸收谱峰组成,在1800~1000 cm-1范围不同产地样本的原始光谱存在微小的差异.对光谱进行一阶导数和二阶导数处理,用导数光谱进行系统聚类分析(HCA),结果显示,一阶导数光谱在1800~1000 cm-1范围按不同产地样本聚类效果较好,63个样本按5个不同产地很好地聚类,分类正确率达到了90.5%.结果提示傅里叶变换红外光谱结合系统聚类分析可以快速、方便地对不同产地野生蕈菌进行鉴别分类.  相似文献   

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