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紫薯色素的变色范围及吸收光谱特性研究 被引量:2
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作者 高向阳 高遒竹 张娜 《河南农业大学学报》 CSCD 北大核心 2017年第5期725-729,共5页
为研究紫薯色素的变色范围和吸收光谱特性,以郑州市市售紫薯为样品,在优选的条件下提取其色素,以电位滴定法和吸光光度法进行测定。结果表明,紫薯色素在酸性溶液中,吸收光谱的波峰在530 nm左右,在碱性溶液中,波峰为600~620 nm;在强碱性... 为研究紫薯色素的变色范围和吸收光谱特性,以郑州市市售紫薯为样品,在优选的条件下提取其色素,以电位滴定法和吸光光度法进行测定。结果表明,紫薯色素在酸性溶液中,吸收光谱的波峰在530 nm左右,在碱性溶液中,波峰为600~620 nm;在强碱性溶液中波峰消失。紫薯色素的变色范围为7.3~7.8,只有0.5个pH单位,变色极其敏锐,可作为一种天然的酸碱指示剂和安全的食品着色剂,在食品工业中加以应用。 展开更多
关键词 紫薯色素 变色范围 吸收光谱特性 PH电位滴定法
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利用近红外吸收光谱特性实现酒精浓度的非接触式测量系统的设计
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作者 王添 吴卫 张紫芸馨 《红外与激光工程》 EI CSCD 北大核心 2023年第12期166-172,共7页
酒精浓度的非接触式测量是一种新型的测量方法。对一些特殊行业有着很大的帮助,比如酿酒业测量酒的酒精浓度,工业上生产工业酒精等。为了便于测量不能接触的酒精溶液,文中设计了一种基于近红外吸收光谱特性的酒精浓度测量系统,可以对不... 酒精浓度的非接触式测量是一种新型的测量方法。对一些特殊行业有着很大的帮助,比如酿酒业测量酒的酒精浓度,工业上生产工业酒精等。为了便于测量不能接触的酒精溶液,文中设计了一种基于近红外吸收光谱特性的酒精浓度测量系统,可以对不同浓度的酒精溶液进行非接触式连续测量。对于酒精来说,在1300~1350 nm的光谱段浓度定性反应非常明显,使用处于该波段的红外LED发光二极管,加上光电二极管、模数转换芯片、单片机和LCD屏幕组成该系统。通过使用该系统对不同浓度的酒精进行测量,利用最小二乘法找到酒精浓度和电压信号之间的函数关系式。这样就能通过测量电压值来反推出酒精浓度值。实验表明,在该红外波段下,采集到的电压值和酒精浓度之间有良好的二次函数关系,拟合优度达到了0.99946。测量结果显示,测量值和标准值之间的相关系数R为0.999911,平均绝对误差为0.64。与传统酒精计的0.5相差不大,重复测量和连续测量的方差分别为0.0044和0.0056,证明了该装置的稳定性和可靠性符合预期。而且通过优化电路和程序,选择更为精确的酒精计作为标准,可以使误差更小。该方案相比传统测量方法结构简单,速度更快,还可以进行连续测量。在现实生活中,制酒业、医疗行业和工业生产等行业都对于测量酒精浓度有着很高的需求。该装置可以在不损坏产品的情况下进行酒精浓度测量,它的连续检测能力对某些行业的批量生产有着很大的帮助。通过改良,可以实现自动化检测。除了企业生产,也可用于制造日常使用的便携式酒精浓度测量仪。 展开更多
关键词 酒精浓度测量 近红外吸收光谱特性 非接触测量 光电二极管 红外LED光源
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有序CdS纳米线阵列的制备和光学特性 被引量:2
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作者 孙岚 林昌健 《电化学》 CAS CSCD 2004年第2期154-158,共5页
 应用直流电沉积法在多孔氧化铝模板中制备了高度有序的CdS纳米线阵列,并由XRD、Raman、SEM、TEM和HRTEM等进行物理化学表征.结果表明,沉积在多孔氧化铝模板中的CdS呈六角结构,c轴沿孔长度方向定向生长.紫外吸收光谱研究表明,随着纳米...  应用直流电沉积法在多孔氧化铝模板中制备了高度有序的CdS纳米线阵列,并由XRD、Raman、SEM、TEM和HRTEM等进行物理化学表征.结果表明,沉积在多孔氧化铝模板中的CdS呈六角结构,c轴沿孔长度方向定向生长.紫外吸收光谱研究表明,随着纳米线尺寸的减小,纳米线阵列的吸收边向短波长方向移动,荧光光谱测量显示,CdS纳米线阵列的荧光强度高于氧化铝模板,而且在可见光区的荧光特性与激发波长无关. 展开更多
关键词 硫化镉 半导体纳米线阵列 直流电沉积法 多孔氧化铝模板 制备 紫外可见吸收光谱特性 荧光光谱特性
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Immunogenicity and protective efficacy of Vibrio harveyi pcFlaA DNA vaccine in Epinephelus awoara 被引量:1
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作者 覃映雪 苏永全 +1 位作者 王世峰 鄢庆枇 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2009年第4期769-774,共6页
The FlaA gene from Vibrio harveyi marker, was cloned into the eukaryotic expression with a short nucleotide sequence encoding the Flag vector pcDNA3.1(+) (designated as pcFlaA). Ninety grouper (Epinephelus awoar... The FlaA gene from Vibrio harveyi marker, was cloned into the eukaryotic expression with a short nucleotide sequence encoding the Flag vector pcDNA3.1(+) (designated as pcFlaA). Ninety grouper (Epinephelus awoara) were separated into three equal size groups. An experimental group was immunized with pcFlaA, Control I group was immunized with the vector pcDNA3.1(+), and Control 1I group was immunized with PBS. The expression of pcFlaA mRNA and protein was examined using reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry. We also evaluated the immunogenicity and protective efficacy of pcFlaA against V. harveyi by measuring the lymphocyte proliferation response and serum levels of specific antibody and conducting a bacterial challenge test. We successfully transfected the fish muscle with pcFlaA. The pcFlaA mRNA and protein was expressed in the muscle cells for up to one month following injection. The proliferation response of lymphocytes in fish immunized with pcFlaA was significantly higher than in control group II. Furthermore, the immunized fish generated specific antibody. The vaccination also resulted in significantly higher survival during the bacterial challenge test. 展开更多
关键词 Vibrio harveyi DNA vaccination IMMUNOGENICITY protective efficacy
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Characterization of Water Constituents Spectra Absorption in Chagan Lake of Jilin Province, Northeast China 被引量:1
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作者 WANG Yuandong LIU Dianwei +6 位作者 SONG Kaishan DU Jia WANG Zongming ZHANG Bai TANG Xuguang LEI Xiaochun WU Yanqing 《Chinese Geographical Science》 SCIE CSCD 2011年第3期334-345,共12页
Research on the optical characteristics of water color constituents in Chagan Lake of Jilin Province,Northeast China was carried out in order to investigate the variability of the spectra absorption parameters as inpu... Research on the optical characteristics of water color constituents in Chagan Lake of Jilin Province,Northeast China was carried out in order to investigate the variability of the spectra absorption parameters as inputs to bio-optical models and remote sensing algorithms for converting observed spectral signals into water quality information.Samples of total particulates,non-algal particles and colored dissolved organic matter (CDOM) were first prepared by quantitative filter technique (QFT) and then absorption coefficients of these color producing agents were determined by spectrophotometry.Spectral characteristics of absorption coefficients by total particulate matter,spectral specific absorption dependency on chlorophyll concentration (Chl-a) of phytoplankton,spectral absorption slopes variation for CDOM and non-algal particles and their corresponding reasons were examined and clarified over five months of 2009 and 2010 in this study.Results suggest that total particulate spectral absorption in Chagan Lake is mainly dominated by non-algal particles in most cases,but phytoplankton could be the dominant contributor when chlorophyll concentration is high (up to 84.48 mg/m3 in autumn 2010).The specific absorption coefficients of phytoplankton particulate (a*ph(λ)) dependency on Chl-a is significantly variable due to relative contributions of package effect and accessory pigments,and the parameters of power function are clearly biased on a long time span.The sources of variability in spectral absorption slopes of CDOM and non-algal particles are mainly attributed to the changing proportions of high molecular weight humic acids and mineral suspended sediments in waters,respectively. 展开更多
关键词 colored dissolved organic matter spectra absorption water constituents spectral slope Chagan Lake
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Upconversion Luminescence of Er^3+ and Co-Doped Er^3+/Yb^3+ Novel Transparent Oxyfluoride Glasses and Glass Ceramics: Spectral and Structural Properties
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作者 Arzumanyan Grigory Vartic Victoria +6 位作者 Kuklin Alexander Soloviov Dmitry Rachkovskaya Galina Zacharevich Galina Trusova Ekaterina Skoptsov Nikolay Yumashev Konstantin 《Journal of Physical Science and Application》 2014年第3期150-158,共9页
Transparent oxyfluoride silicate precursor glasses and glass ceramics with the novel composition (1) SiO2-PbO-PbFE-Er2O3, (2) SiO2-GeOE-PbO-PbFE-Er2O3 (3) SiO2-Al2O3-Y2O3-Na2O-NaF-LiF-Er2O3-YbF3 doped with Er^3... Transparent oxyfluoride silicate precursor glasses and glass ceramics with the novel composition (1) SiO2-PbO-PbFE-Er2O3, (2) SiO2-GeOE-PbO-PbFE-Er2O3 (3) SiO2-Al2O3-Y2O3-Na2O-NaF-LiF-Er2O3-YbF3 doped with Er^3+ and co-doped with Er^3+/Yb^3+ ions were synthesized. X-ray diffraction analysis (XRD) and Er3+ absorption spectra revealed precipitation of PbF2 nanocrystals dispersed in the glassy matrix. Under 980 nm laser excitation, intense green, red and near IR bands of upconversion luminescence (UCL) were recorded both before and after heat treatment. In the glass ceramics the upconversion intensity increased significantly. To our knowledge, for the first time the composition of the glass ceramics characterized by the small-angle neutron scattering (SANS) showed the cluster organization of PbF2 nanocrystals. 展开更多
关键词 Visible to near-infrared upconversion rare-earth luminescence oxyfluoride glass ceramics small-angle neutron scattering.
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