Synthesis, Crystal Structure, Thermal Stability and Solid UV-Vis Absorption Spectra of One New Copper(Ⅱ) Coordination Polymer

A new coordination polymer [Cu2(OH)(nbta)(tib)(H2 O)2]n(1, H3 nbta = 5-nitro-1,2,3-benzenetricarboxylic acid, tib = 1-(4 H-1,2,4-triazol-4-yl)-4-(imidazol-1-yl)benzene) constructed from dimeric Cu(Ⅱ) units has been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction analysis. The compound crystallizes in monoclinic system, space group I2/c, with a = 17.8474(9), b = 11.7588(6), c = 21.9221(11) ?, β = 104.419(5)°, V = 4455.7(4) ?3 and Z = 8. Compound 1 is a three-dimensional structure constructed from dimeric Cu(Ⅱ) units and presents a 2-nodal(3,5)-connected net. Moreover, the thermal stability and solid UV-Vis absorption spectra have been investigated.

Effect of Heat-treatment on Crystalline Phase and UV Absorption of 60CeO_2-40TiO_2 Thin Films by Magnetron Sputtering

60CeO2-40TiO2 thin films were deposited on soda-lime silicate glass substrates by R.F. magnetron sputtering. The effects of heat-treatment on the UV-absorption of the thin films were studied on the 60CeO2-40TiO2 thin film with the largest UV cut-off wavelength. The sample films with CeO2：TiO2=60：40 were heated at 773 K, 873 K, 973 K for 30 min. These films are characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and X-ray photoelectron spectroscopy and spectrometer （XPS）. XRD analysis proves that the addition of TiO2 to CeO2 changed the crystalline state of CeO2. But the UV absorption effect of CeO2-TiO2 films with CeO2 crystallite phase is inferior to that of the amorphous phase CeO2-TiO2 films. XPS analysis also indicates that the amorphous phase CeO2-TiO2 films have the most Ce3＋ content in these films. Amorphous phase and crystalline phase of the CeO2-TiO2 films have different effects on UV absorption of the thin films.

Synthesis of rare earth sulfides and their UV-vis absorption spectra

Rare earth sulfides were systematically synthesized via the sulfurization of their commercial oxide powders using CS2 gas to shorten sulfurization time, and their UV-vis absorption spectra were investigated. The appropriate sulfurization conditions were studied. For the rare earth sulfides with the same crystal structure, the sulfurization temperature showed increasing tendency with the decrease of rare earth element atomic radii. The UV-vis absorption spectra of rare earth sulfides did not depend on the crystal structure of rare earth sulfides, but on the 4f electronic structure of rare earth element. The data showed that the optical band gaps of rare earth sulfides were irregular, and the values ranged from 1.65 to 3.75 eV.

The isolation of prophyra-334 from marine algae and its UV-absorption behavior

Prophyra-334 was prepared by methanol extraction and HPLC methods from marine algae (dried laver). It is a sunscreen compound that has good absorption of ultraviolet radiations in the wavelength ranges of 200-400 nm. The absorption maximum wavelength of prophyra-334 is at 334 nm, so defined the name. The mo- lar extinction coefficient (ε) of prophyra-334 in aqueous solution at 334 nm wavelength is 4.23×104. The absorp- tion of prophyra-334 in organic solvents differs in aqueous solutions. In polar organic solvents, the absorption maximum wavelength of prophyra-334 has a slight shift toward longer wavelength compared with that in pure water. On the contrary, in inert non-polar organic solvents, the absorption maximum wavelength and the shape of absorption spectra of prophyra-334 are changed. The effects of organic solvents on prophyra-334 stability sug- gested that: (1) the absorbance of prophyra-334 in water is generally constant at temperature of 60°C in 24 h, meaning that prophyra-334 is quite stable in water; (2) the absorbance of prophyra-334 in ethanol and hexane decreases at the same condition. The stability of prophyra-334 in organic solvents is less than that in aqueous solution. In benzene, the prophyra-334 is very instable.

Preparation of nanometer yellow iron and its UV absorption capacity

The nanometer yellow iron oxide was prepared by oxidizing Fe（OH）2 with air, which was verified with XRD and TEM. The result shows that nanometer yellow iron oxide is spindle-shaped and well-distributed with a long axis of 150-200 nm and short axis of 40-50 nm. Ultraviolet （UV） transmittance of the iron oxide shows the great effect of concentration on both transparency and UV ab- sorption, and it has been proven that iron oxide with a concentration of 0.025wt% is preferred. The spectrum of XRD indicates that it is goethite. When the yellow iron is dispersed in sol, given that the wavelength of UV is less than 300 nm, its UV absorption capacity is superior to those of ZnO and TiO2. The absorption capacity of the yellow iron is less than TiO2 and more than ZnO as the wavelength of UV is 300-400 nm.

Comparison of Nitric Oxide Concentrations in μs-and ns-Atmospheric Pressure Plasmas by UV Absorption Spectroscopy

In this paper,an absorption spectroscopy measurement method was applied on two atmospheric pressure plasma sources to determine their production of nitric oxide.The concentrations are essential for evaluating the plasma sources based on the principle of the Dielectric Barrier Discharge（DBD）for applications in plasma medicine.The described method is based on a setup with an electrodeless discharge lamp filled with a mixture of oxygen and nitrogen.One of the emitted wavelengths is an important resonance wavelength of nitric oxide（λ = 226.2 nm）.By comparing the absorption behaviour at the minimum and maximum of the spectral absorption cross section of nitric oxide around that wavelength,and measuring the change in intensity by the absorbing plasma,the concentration of nitric oxide inside the plasma can be calculated.The produced nitric oxide concentrations depend on the pulse duration and are in the range of 180 ppm to 1400 ppm,so that a distance of about 10 cm to the respiratory tract is enough to conform to the VDI Guideline 2310.

Preparation and UV-light Absorption Property of Oleic Acid Surface Modified ZnO Nanoparticles

Syntheses of zince oxide（ZnO） nanoparticles by direct precipitation and surface modification with oleic acid were reported. ZnO nanoparticles were characterized via X-ray diffractometry（XRD）, transmission electron microscopy（TEM）, infrared spectroscopy（IR） and UV-Vis spectroscopy. The prepared ZnO nanoparticles were nearly spherical and highly crystalline with an average size of 29 nm. In addition, high UV-light absorption properties of oleic acid surface modified ZnO nanoparticles were successfully obtained for a dispersion of ZnO nanoparticles in ethanol.

Exciplex formation and electroluminescent absorption in ultraviolet organic light-emitting diodes

We investigated the formation of exciplex and electroluminescent absorption in ultraviolet organic light-emitting diodes（UV OLEDs） using different heterojunction structures.It is found that an energy barrier of over 0.3 eV between the emissive layer（EML） and adjacent transport layer facilitates exciplex formation.The electron blocking layer effectively confines electrons in the EML,which contributes to pure UV emission and enhances efficiency.The change in EML thickness generates tunable UV emission from 376 nm to 406 nm.In addition,the UV emission excites low-energy organic function layers and produces photoluminescent emission.In UV OLED,avoiding the exciplex formation and averting light absorption can effectively improve the purity and efficiency.A maximum external quantum efficiency of 1.2%with a UV emission peak of 376 nm is realized.

适用于UV喷印的尼龙废丝涂层商标织物的制备及性能

选用5种不同来源的尼龙废丝,用甲醇/氯化钙溶解后,加入高岭土制备涂层浆,并利用湿法涂层工艺制备尼龙废丝涂层织物,研究了其UV喷印性能。结果表明,当氯化钙质量为240 g,高岭土质量为76 g,选用1#普通开刀丝制备的涂层织物吸墨性、耐摩擦色牢度、耐皂洗色牢度均较优异,说明利用尼龙废丝可以制备出适合UV喷印的商标织物。

Highly enhanced UV absorption and light emission of monolayer WS_(2)through hybridization with Ti_(2)N MXene quantum dots and g-C_(3)N_(4)quantum dots

Two-dimensional(2D)transition metal dichalcogenides(TMD)are atomically thin semiconductors with promising optoelectronic applications across the visible spectrum.However,their intrinsically weak light absorption and the low photoluminescence quantum yield(PLQY)restrict their performance and potential use,especially in ultraviolet(UV)wavelength light ranges.Quantum dots(QD)derived from 2D materials(2D/QD)provide efficient light absorption and emission of which energy can be tuned for desirable light wavelength.In this study,we greatly enhanced the photon absorption and PLQY of monolayer(1L)tungsten disulfide(WS_(2))in the UV range via hybridization with 2D/QD,particularly titanium nitride MXene QD(Ti_(2)N MQD)and graphitic carbon nitride QD(GCNQD).With the hybridization of MQD or GCNQD,1LWS_(2)showed a maximum PL enhancement by 15 times with 300 nm wavelength excitation,while no noticeable enhancement was observed when the excitation photon energy was less than the bandgap of the QD,indicating that UV absorption by the QD played a crucial role in enhancing the light emission of 1L-WS_(2)in our 0D/2D hybrid system.Our findings present a convenient method for enhancing the photo-response of 1L-WS_(2)to UV light and offer exciting possibilities for harvesting UV energy using 1L-TMD.

紫外吸收光谱结合SPA-ELM算法的水体磷酸根离子检测研究

在工业锅炉中随着水蒸气蒸发,大量的钙镁离子留在炉水中,如果不加处理,在水冷管中会形成水垢,造成爆管停炉。为了保障设备的安全运行,消除安全隐患,工业上通过维持水中一定含量的磷酸根离子来去除锅炉中的钙、镁水垢。传统的磷酸根离子检测技术主要有比色法、分光光度法、色谱法、电位法等,这些方法前期处理步骤较繁琐且耗时较长。光谱法是通过测定物质的吸收光谱并建立和浓度关系的数学模型,对物质浓度定量的一种分析方法。为了满足磷酸根离子快速、实时测量的要求,提出了一种基于紫外吸收光谱结合SPA-ELM算法快速测量磷酸根离子的方法。按照我国《工业锅炉水质GB/T 1576—2018》中所规定的进入热水锅炉前的水质参数要求,配置37份浓度范围在5~100 mg·L^(-1)磷酸根溶液,使用搭建的实验装置,采集紫外吸收光谱。使用SPXY将样品按照7∶3的比例随机划分训练集、测试集;使用Savitzky-Golay(S-G)滤波对数据预处理以提高光谱的信噪比;通过连续投影算法(SPA)压缩光谱数据,筛选出5个与磷酸根强相关的特征波长;使用极限学习机(ELM)将特征波长处的吸光度与样本浓度进行拟合,以决定系数R2和均方根误差RMSE作为模型评价指标,建立磷酸根离子的回归模型。采用所提出的建模方法所建立的模型训练集的R2与RMSE分别为0.9972和1.3015 mg·L^(-1),测试集的R^(2)与RMSE分别为0.9995和0.5174 mg·L^(-1)。为了验证所提出的SPA-ELM预测模型效果,另外建立了LASSO-ELM、PCA-ELM、SPA-PLS和SPA-SVR四种预测模型进行对比。实验结果表明,SPA-ELM建立的预测模型的R2和RMSE均优于其他四种预测模型,说明采用的特征选择方法和回归方法均为最优,能够对磷酸根浓度范围为5~100 mg·L^(-1)的水体进行准确预测,为水中磷酸根离子的检测提供了一种新的解决方法。

烟草废弃物提取物的双水相萃取及其化妆品功效研究

采用双水相萃取法制备烟草废弃物提取物,探究不同萃取条件对其中上相多酚得率的影响,并探讨其抗氧化活性、紫外吸收特性和细胞毒性。结果表明:当料液质量比为1∶60,搅拌时间为30 min,(NH4)2SO4质量分数为23.3%,乙醇质量分数为23.5%时,上相多酚得率最高,为48.59 mg/g;该萃取条件下,烟草废弃物提取物具有较好的抗氧化活性,当质量浓度为2 mg/mL时,对DPPH自由基清除率达98%,对ABTS自由基清除率达78%;当提取物质量浓度为0.5 mg/mL时,具有较好的紫外吸收特性,有一定的光防护功效;当提取物质量浓度在0~1.2 mg/mL范围内时,对Hacat细胞无细胞毒性,有望成为天然无刺激的功效型化妆品原料。

棉和羽毛蛋白丝交织物的性能测试

对棉和羽毛蛋白丝交织物进行吸湿速干、透湿、抗静电和防紫外线性能测试,并与棉织物和棉涤纶丝织物进行对比分析,得出结论:棉羽毛蛋白丝织物的吸水率、滴水扩散时间、芯吸高度达到GB/T 21655.1—2023中吸湿速干织物Ⅱ级的要求,但干燥速率未达到吸湿速干织物要求:棉羽毛蛋白丝织物透湿性能较好,抗静电性能优异,符合防紫外线产品要求;棉羽毛蛋白丝织物适宜用作夏季服装面料。

表儿茶素的碳酰化改性及其紫外吸收和抗氧化活性

为增强表儿茶素衍生物的紫外吸收性能、改善其在油脂等非极性溶剂中的溶解度,以甲烷磺酸为溶剂和催化剂,由表儿茶素和对羟基苯甲酸合成了2,2'-二(对羟基苯甲酮基)-表儿茶素,经柱层析分离得到目标产物,采用高效液相色谱(HPLC)验证纯度,运用紫外-可见光(UV-vis)光谱、傅里叶变换红外(FT-IR)光谱、液相色谱-质谱联用(LC-MS)和核磁共振(NMR)波谱等表征手段确证目标产物结构。评价了2,2'-二(对羟基苯甲酮基)-表儿茶素的紫外吸收性能,以及对2,2-联氮-二(3-乙基苯并噻唑-6-磺酸)二铵盐阳离子自由基、1,1-二苯基-2-三硝基苯肼自由基和超氧阴离子自由基清除能力。结果表明,合成的2,2'-二(对羟基苯甲酮基)-表儿茶素与常用紫外线吸收剂4-甲氧基肉桂酸-2-乙基己酯(OMC)具有相似的紫外吸收范围和相当的摩尔吸光系数,有望成为一种性能优良的UVB波段紫外线吸收剂;2,2'-二(对羟基苯甲酮基)-表儿茶素具有良好的体外抗氧化活性,其体外抗氧化能力高于维生素C(VC)、略低于表儿茶素,有望应用于化妆品领域。

UV-Vis光谱差减法测定油橄榄叶中橄榄苦苷含量初探

建立了紫外-可见(UV-Vis)分光光谱测定油橄榄叶中橄榄苦苷含量的方法。以芦丁和橄榄苦苷为对照品,分别采用NaNO2-Al(NO3)3-NaOH络合体系和AlCl3络合体系进行显色。以NaNO2-Al(NO3)3-NaOH体系显色后于510 nm处可测得油橄榄叶中总黄酮和橄榄苦苷的吸光度之和;而以AlCl3体系显色后于415 nm处仅测得总黄酮的吸光度,橄榄苦苷无吸收。利用橄榄苦苷在两种显色体系中的吸收特性差别,通过差减法换算后可间接测定样品中橄榄苦苷的含量。以UV-Vis差减法测得油橄榄叶及其纯化浸膏中橄榄苦苷的平均含量分别为11.6%和63.4%,3次测定的相对标准偏差(RSD)分别为1.5%和1.2%,其结果与高效液相色谱法(HPLC)测定结果的相对误差小于4.0%。该方法可替代HPLC用于油橄榄叶中橄榄苦苷的含量测定,为油橄榄叶及其制品的质量控制提供了一种快速、简便、成本低廉的分析方法。

UV照射大肠杆菌对其吸收光谱的影响

探讨了样品池溶液及分光光度计内置紫外光对大肠杆菌吸收光谱测定的影响。发现样品池溶液(2.8 mL双蒸水+0.1 mL生理盐水+0.1 mL LB培养基)较为合理,既给细菌提供了有利的生存环境,又对细胞的紫外吸收影响较小;研究同时发现在257 nm波段150 s内细胞吸收强度基本没有变化,说明内置的紫外光不会影响试验测定结果。在此基础上,研究了UV照射0,20,40,60,80,120 s大肠杆菌吸收光谱的变化情况。结果显示随着UV照射剂量的增加,大肠杆菌吸收光谱存在一个先降后升再降的现象。该现象反映了辐射中细胞损伤死亡和修复存活的生物学效应。该研究从光谱学角度探讨了UV对大肠杆菌细胞的损伤作用,对利用光谱技术研究细胞的辐射损伤、死亡和修复具有一定参考意义。

四氮杂芳氧基取代酞菁金属配合物的UV-Vis吸收光谱研究

测定了6个系列18种四氮杂芳氧基取代酞菁金属配合物（R4PCM，R=4-吡啶氧基、8-喹啉氧基、2-甲基-8喹啉氧基；取代位置分别为：α位及β位；M=Ni（Ⅱ），Cu（Ⅱ），Zn（Ⅱ））的UV-Vis吸收光谱。探讨了中心金属、取代基种类及取代位置、溶剂对酞菁金属配合物UV-Vis吸收光谱中Q带最大吸收波长（λmax）的影响，实验结果表明：标题配合物的Q带λmax在680nm左右；与相同中心金属无取代酞菁金属配合物（669～671nm）比较，标题配合物的Q带λmax都发生了不同程度的红移；当取代基在α位时其种类对标题配合物Q带λmax的影响较在β位时显著，且相同取代基及中心金属的α位取代配合物的Q带λmax较β位取代配合物的红移更为明显；中心金属、溶剂对标题配合物的Q带λmax影响不明显。

磺酸基对掺杂酞菁在溶胶-凝胶复合体系中UV/Vis吸收光谱的影响

选择、设计具有代表性无取代酞菁镍(NiPc)和周环带有4个磺酸基的四磺化酞菁镍(NiTSPc),采用溶胶-凝胶湿化学将其均匀掺入SiO2凝胶基质,制备无机基质酞菁掺杂复合光功能材料并考察磺酸基的引入对掺杂酞菁在溶胶-凝胶复合体系中UV/Vis吸收光谱的影响。研究结果表明水溶性磺酸基的引入有助于改善酞菁的溶解性,进而实现其与溶胶-凝胶体系的稳定互溶,使酞菁均匀掺杂复合材料的制备成为可能。

蚕丝织物的巴西莓生态染色及功能性

为提高蚕丝织物的附加值和多功能性,以天然绿色抗氧化能力强的巴西莓进行生态染色。研究了壳聚糖、阳离子瓜尔胶、木瓜蛋白酶改性对织物K/S值的影响,通过单因素法确定了直接染色的最优工艺,考察了媒染剂氯化铈、单宁酸以及桃胶对织物色牢度的影响,测试了染色织物的色牢度、抗紫外性能以及吸湿导热性能。结果表明:木瓜蛋白酶改性蚕丝织物能够提高巴西莓的上染能力;直接染色最优工艺为pH=4,温度50℃,时间50 min,浴比1∶40;氯化铈同浴媒染时织物K/S值最大,但匀染性较差;染色后蚕丝织物耐摩擦和耐水洗色牢度均能达到3级,紫外防护性能以及吸湿导热性能得到增强。