Growth, Structural and Microhardness Studies on New Semiorganic Single Crystals of Calcium Para Nitrophenolate Dihydrate

Good quality crystals of calcium p-nitrophenolate （NPCa） were grown from saturated solution by slow evaporation method. The crystal structure analysis and the molecular arrangement of these crystals were determined using X-ray diffraction （XRD）. From Single crystal XRD studies, NPCa is found to be crystallized in the mon- oclinic system with a space group P21/n. The functional groups of the material were confirmed qualitatively by F-FIR （Fourier transform infrared spectroscopy） spectral analysis. Optical absorption studies reveal the absorption region and microhardness studies were carried out to confirm the mechanical behaviour of the crystals.     

邻菲咯啉锌(Ⅱ)配合物[Zn(phen)_3]·(ClO_4)_2的水热合成、晶体结构及光谱性质

用水热法合成了一种新的配合物[Zn(phen)3].(ClO4)2,并用X-射线衍射分析、元素分析、红外光谱、紫外光谱及荧光光谱对其结构进行了表征。配合物的晶体结构属于单斜晶系,空间群为P21/n,晶胞参数为a=1.355 36(14)nm,b=2.559 3(3)nm,c=2.077 1(2)nm,β=109.04°,V=6.810 8(12)nm3,Z=8,Dc=1.570g.cm-3,μ=0.942 mm-1,F(000)=3 280。该配合物中心离子是一个典型的八面体配位构型。     

主成分分析联合Fisher判别在紫外-可见光谱法水质检测中的应用

水质类型的判别是实现光谱法水质参数准确检测的重要前提。针对直接光谱法水质检测系统采集的光谱数据信息冗余较大的问题, 利用主成分分析消除信息指标间的相关性,实现光谱数据的降维和特征信息提取。采集某化工厂和某溪水水样的紫外-可见光谱数据, 利用主成分分析联合Fisher判别的方法建立判别模型,以12组水样光谱数据作为训练样本,6组作为测试样本,对模型的判别能力进行论证和检验,并与传统的Fisher判别模型进行对比实验。实验结果表明,利用主成分分析联合Fisher判别模型可以有效消除信息冗余带来的影响,相比传统的Fisher判别模型具有分类精度高、回代误判率为零、计算时间短等优点,计算时间由传统Fisher判别方法的0.6733 s减少到0.6012 s。该方法为直接光谱法水质类型判别工程实用化提供了一种高效手段。     

有机半导体Butyl-PBD的DFT理论计算研究

采用密度泛函理论(DFT)方法对2-(4-叔丁苯基)-5-(4-联苯基)-1,3,4-恶二唑(Butyl-PBD)进行了B3LYP/6-31G水平上的分子结构优化、红外光谱、Raman光谱、紫外-可见光谱、分子前线轨道、分子电子密度、Mulliken电荷等理论计算.研究结果表明:理论计算结果与实验数据吻合得较好,对IR、THz、UV-Vis吸收光谱和Raman散射光谱中的特征峰进行了归属,发现Butyl-PBD在0.1～10 THz波谱范围内有五个明显的吸收峰,分别位于2.04THz、3.48THz、5.16THz、6.60THz及7.08THz,Butyl-PBD在紫外光波段有三个吸收波段,分别对应于326.76nm、279.60nm及269.31 nm,其中326.76nm的紫外吸收峰最强.电子密度计算表明,最大电子密度集中在O原子上,N原子的电子密度次之.Mulliken电荷计算表明,负电荷主要集中在O原子和N原子上,所有H原子的Mulliken电荷都为正电荷,C原子的Mulliken电荷则与其具体位置相关.     

TiO2薄膜的溶胶-凝胶法制备及其光学特性

采用溶胶-凝胶法在普通载玻片上制备了均匀透明的纳米TiO2薄膜，X射线衍射结果表明薄膜晶粒大小为23．0nm，呈锐钛矿型。通过测量薄膜的紫外可见光透射率和吸光度光谱，对其光学特性和吸收边缘进行了研究，同时计算了薄膜的光学禁带宽度。实验结果表明：随薄膜层数的减少，光吸收带边缘发生了蓝移，光学禁带宽度随之变大，此现象可用量子尺寸效应来解释。     

An Alternative Procedure to Quantify Soot in Engine Oil by Ultraviolet-Visible Spectroscopy

Abstract

Due to new pollutant emissions standards, internal combustion engines need several emission control strategies (and related procedures) such as exhaust gas recirculation, diesel/gasoline particulate filters, and selective catalyst reduction that allow them to comply with complete requirements defined on those standards. These strategies result in faster degradation of engine oil, one of the most relevant consequences of which is an increase in soot contamination level. All of these strategies facilitate soot generation. Consequently, soot is one of the most important contaminants present in engine oil. The main technique to measure the content of soot in oil is thermogravimetric analysis (TGA), but this technique has certain limitations. TGA requires a long and specific procedure and has limitations in measuring small concentrations of soot in oil. Therefore, the design of an alternative technique to quantify soot in oil is relevant. One alternative is Fourier transform infrared (FTIR) spectroscopy, but it also has limitations related to low concentrations of soot in oil. This work presents an alternative technique based on ultraviolet-visible (UV-Vis) spectroscopy that allows quantification of small soot contents in used engine oil samples and avoids potential interference from other typical contaminants or those related to measurement processes, such as sample cuvette material.     

Fabrication and Characterization of Gelatin Stabilized Silver Nanoparticles under UV-Light

Silver nanoparticles (Ag-NPs) were successfully synthesized using the UV irradiation of aqueous solutions containing AgNO(3) and gelatin as a silver source and stabilizer, respectively. The UV irradiation times influence the particles' diameter of the Ag-NPs, as evidenced from surface plasmon resonance (SPR) bands and transmission electron microscopy (TEM) images. When the UV irradiation time was increased, the mean size of particles continuously decreased as a result of photoinduced Ag-NPs fragmentation. Based on X-ray diffraction (XRD), the UV-irradiated Ag-NPs were a face-centered cubic (fcc) single crystal without any impurity. This study reveals that the UV irradiation-mediated method is a green chemistry and promising route for the synthesis of stable Ag-NPs for several applications (e.g., medical and surgical devices). The important advantages of this method are that it is cheap, easy, and free of toxic materials.     

4-(9-蒽基)-6-辛氧基-1,3,5-三嗪-2-胺的合成及其在酸性介质中的光谱行为研究

以2,4-二氯-6-辛氧基-1,3,5-三嗪为原料,经Kumada偶联及胺化两步反应合成了三嗪胺衍生物:4-(9-蒽基)-6-辛氧基-1,3,5-三嗪-2-胺(AOOTA),总产率为38%.通过紫外-可见吸收光谱及荧光光谱研究了氯仿溶液中AOOTA在乙酸(HOAc)及三氟乙酸(TFA)作用下的光谱行为.研究发现AOOTA与HOAc在基态及激发态下均不能发生双氢键作用,而AOOTA与TFA相互作用基态下形成双氢键复合物,激发态下由于分子中蒽基及辛氧基与三嗪环间的C—C单键以及C—O单键的自由旋转,从而使得AOOTA与TFA分子间不能形成有效的氢键相互作用.     

Saccharomyces cerevisiae biosorbed with grape pomace flavonoids: adsorption studies and in vitro simulated gastrointestinal digestion

The residual Saccharomyces cerevisiae from brewing was used as a biosorbent of flavonoids of hydro alcoholic extract from samples of grape pomace (Merlot and Tannat). Biosorption assays verified that the pseudo-second order kinetic model and the Dubinin-Raduschkevich isotherm model presented the best fit, with free energy of adsorption (E) of 7.1 and 6.5 kJ for the Merlot and Tannat varieties, respectively, indicating that the yeast has many binding sites and adsorption was a physical process. The analysis of microscopy and spectroscopy showed differences in structure and composition of the yeast after biosorption, demonstrating that the application was effective, which was confirmed by the chromatographic analysis, where a reduction in 17% and 50% in the catechin peak was observed in the Merlot and Tannat samples, respectively. Finally, there was an increase in the in vitro bioaccessibility of flavonoids in 68% for the Merlot sample and 88% for Tannat, reaching the main objective of this application.     

棒状金纳米粒子的制备及其光谱特性

以银离子为辅助粒子,十六烷基三甲基溴化铵(CTAB)为表面活性剂,抗坏血酸为弱还原剂,利用晶种法制备棒状金纳米粒子,着重研究晶种用量与氯金酸量的比例对棒状纳米粒子形状和产率的影响。利用透射电子显微镜（TEM）和X射线衍射（XRD）仪对纳米粒子的形貌及晶体结构进行分析,利用紫外可见光谱（UV-Vis）对产物进行光谱表征。结果表明,纳米棒为面心立方结构,其UV-Vis出现位于530 nm处的短波吸收和970~980 nm的长波吸收,随着晶种与氯金酸用量比例的增加,纳米棒的长径比出现先增大后减小的趋势,并最终形成球形颗粒。最后探讨晶种用量影响金纳米棒生长的机制。