Molecular distillation was used to recover ionic liquid(IL) 1-allyl-3-methylimidazolium chloride(AmimCl) in homogeneous cellulose acetylation.The five factors that affect the separation efficiency of molecular distill...Molecular distillation was used to recover ionic liquid(IL) 1-allyl-3-methylimidazolium chloride(AmimCl) in homogeneous cellulose acetylation.The five factors that affect the separation efficiency of molecular distillation,namely,feed flow rate,distillation temperature,feed temperature,wiper rotating speed,and distillation pressure,are discussed.The optimal recovery condition was determined via orthogonal experiments using an OA9(34) design.The IL was recycled and reused 5 times in the homogeneous cellulose acetylation system under optimal conditions.The purity of recycled IL the 5th time reached 99.56%.FT-IR(Fourier transform infrared spectroscopy) and 1H NMR(nuclear magnetic resonance) spectroscopy showed that the structure of the recovered IL is not changed.This work proves that AmimCl has excellent reusability,and that molecular distillation is an effective method for recovering IL in homogeneous cellulose acetylation.展开更多
The absorption spectrum of NiI between 445 and 510 nm has been investigated using the technique of laser vaporization/reaction with free jet expansion and cavity ring down laser absorption spectroscopy. Two new transi...The absorption spectrum of NiI between 445 and 510 nm has been investigated using the technique of laser vaporization/reaction with free jet expansion and cavity ring down laser absorption spectroscopy. Two new transitions namely,[21.3]^2△5/2-X^2△5/2 and [21.9]^2Ⅱ3/2-X^2△5/2 systems were identified and studied. Spectra of both ^58NiI and ^60NiI isotopic molecules were observed. Equilibrium molecular constants for both electronic states are reported and the equilibrium bond length for the [21.3]^2△5/2 state and the[21.9]^2Ⅱ3/2 state was respectively determined to be 2.431 and 2.481 A.展开更多
There are many well-known analytical methods for determination of iron（Ⅱ） and iron（Ⅲ）. Among these methods： Gravimetric, titrimetric, potentiometric, conductometric and batch and flow-injection spectrophotometr...There are many well-known analytical methods for determination of iron（Ⅱ） and iron（Ⅲ）. Among these methods： Gravimetric, titrimetric, potentiometric, conductometric and batch and flow-injection spectrophotometric methods. In present study, two batch spectrophotometric, atomic absorption spectrometric and biolabo kit methods have been used for determination of iron（Ⅱ）, iron（Ⅲ） and total iron. The present methods have the advantages of high sensitivity, low cost reagent, low operation cost, simplicity, speed and their applications for determination of iron（Ⅱ） and iron（Ⅲ） in some serum samples of normal human and fl-thalasemia patients in Erbil city. For the first time especially in Erbil city attempts were made to use zero, first and second derivative spectra to identify the serum samples of some β-thallasemia patients from the normal human serum samples due to the appearance and resolution of peaks in both cases.展开更多
A novel analysis approach using atomic fluorescence excited by synchrotron radiation is presented. A system for synchrotron radiation-atomic fluorescence spectrometry is developed, and experimental conditions such as ...A novel analysis approach using atomic fluorescence excited by synchrotron radiation is presented. A system for synchrotron radiation-atomic fluorescence spectrometry is developed, and experimental conditions such as flow rate, analyte acidity, concentration of pre-reducing and hydrogenation system are optimized. The proposed method is successfully applied to get an excitation spectrum of arsenic. Seven of ten primary spectral lines, four of which have never been reported by means of atomic fluorescence spectrometry, agree well with the existing reports. The other three are proposed for the first time. Excitation potentials and possible transitions are investigated. Especially for the prominent line at 234.99 nm, the mechanism of generation is discussed and a model of energy transition processes is proposed.展开更多
Cerium （III） tetraphenylporphyrin nitrate Ce（TPP）NO3 was synthesized by using meso- tetraphenylporphyrin （TPP） and Ce（NO3）.6H20 in mixture solution of CHC13 and C2HsOH （V：V=1：1）. The complex was characteri...Cerium （III） tetraphenylporphyrin nitrate Ce（TPP）NO3 was synthesized by using meso- tetraphenylporphyrin （TPP） and Ce（NO3）.6H20 in mixture solution of CHC13 and C2HsOH （V：V=1：1）. The complex was characterized by UV-Vis, FT-IR, conventional fluorescence, MALDI-TOF-MS, and ^1H NMR spectral techniques. The structure of complex was proposed viaSpectral analyses, in which tetraphenylporphyrin was coordinated to a cerium ion in a tetradentate fashion, while one nitrate was coordinated to the same cerium ion. After bubbling NO to the solution of Ce（TPP）NO3 in CH2Cl2, spectral analyses suggested that Ce（TPP）NO3 could interact with NO to form a novel complex of Ce（TPP）（NO）NO3, and NO was coordinated to the center cerium ion. When nitrogen was poured into the Ce（TPP）（NO）（NO3） solution, the complex could be reduced to Ce（TPP）NO3.展开更多
The encapsulation of essential oil components in cyclodextrins(CDs)to form inclusion complexes(ICs)is an effective strategy for improving their stability and bioaccessibility.The aim of the present study was to obtain...The encapsulation of essential oil components in cyclodextrins(CDs)to form inclusion complexes(ICs)is an effective strategy for improving their stability and bioaccessibility.The aim of the present study was to obtain a deeper understanding of the encapsulation behavior of multi-components inβ-CD.Guest molecules ofα-pinene,myrcene,and 3-carene,having the same molecular weight,formed ICs withβ-CD by a freeze-drying method.A simplex lattice mixture design with 28 experiments was carried out.Statistical analysis was applied to analyze the encapsulation behavior of guest components,and quantitative models of guest components in ICs were constructed by coupling with near-infrared(NIR)spectroscopy and chemometrics analysis.Besides,the molecular docking technique was used to obtain the optimal conformation and explain the binding behavior of inclusion.The results suggested that the spatial structure and ratio of guest molecules were the key factors affecting the encapsulation effect.A non-destructive and rapid NIR analytical model for the guest component in ICs could be obtained by second derivative(2nd der)pretreatment.Collectively,the encapsulation of guest components inβ-CD was differentiated,and NIR could be used as a rapid and non-destructive tool for quantitative analysis of ICs.展开更多
We investigate nanorod assemblies of two 64-substituted pentacenes, namely （2,3-X2-9,10-Y2）-substituted pentacenes with X -- Y = OCH3 （MOP） and with X = F, Y-- OCH3 （MOPF）, grown on Au（111） single crystals. By...We investigate nanorod assemblies of two 64-substituted pentacenes, namely （2,3-X2-9,10-Y2）-substituted pentacenes with X -- Y = OCH3 （MOP） and with X = F, Y-- OCH3 （MOPF）, grown on Au（111） single crystals. By using a multi-technique approach based on ultraviolet photoelectron spectroscopy X-ray photoelectron spectroscopy; and X-ray absorption, we find evidence for charge transfer screening at the interface with gold. Furthermore, the MOP and MOPF nanorods show a rough surface morphology, which was investigated with atomic force microscopy. We use molecular simulation techniques to investigate the energetic barriers to diffusion and to traverse step-edges to estimate their influence on the nanorod roughness. We find that barriers to surface diffusion on a terrace are anisotropic and that their direction favors the formation of nanorods in these materials.展开更多
基金Supported by the Major Project of the State Key Development Program for Basic Research of China（2009CB219901）the National Natural Science Foundation of China（21006118）
文摘Molecular distillation was used to recover ionic liquid(IL) 1-allyl-3-methylimidazolium chloride(AmimCl) in homogeneous cellulose acetylation.The five factors that affect the separation efficiency of molecular distillation,namely,feed flow rate,distillation temperature,feed temperature,wiper rotating speed,and distillation pressure,are discussed.The optimal recovery condition was determined via orthogonal experiments using an OA9(34) design.The IL was recycled and reused 5 times in the homogeneous cellulose acetylation system under optimal conditions.The purity of recycled IL the 5th time reached 99.56%.FT-IR(Fourier transform infrared spectroscopy) and 1H NMR(nuclear magnetic resonance) spectroscopy showed that the structure of the recovered IL is not changed.This work proves that AmimCl has excellent reusability,and that molecular distillation is an effective method for recovering IL in homogeneous cellulose acetylation.
文摘The absorption spectrum of NiI between 445 and 510 nm has been investigated using the technique of laser vaporization/reaction with free jet expansion and cavity ring down laser absorption spectroscopy. Two new transitions namely,[21.3]^2△5/2-X^2△5/2 and [21.9]^2Ⅱ3/2-X^2△5/2 systems were identified and studied. Spectra of both ^58NiI and ^60NiI isotopic molecules were observed. Equilibrium molecular constants for both electronic states are reported and the equilibrium bond length for the [21.3]^2△5/2 state and the[21.9]^2Ⅱ3/2 state was respectively determined to be 2.431 and 2.481 A.
文摘There are many well-known analytical methods for determination of iron（Ⅱ） and iron（Ⅲ）. Among these methods： Gravimetric, titrimetric, potentiometric, conductometric and batch and flow-injection spectrophotometric methods. In present study, two batch spectrophotometric, atomic absorption spectrometric and biolabo kit methods have been used for determination of iron（Ⅱ）, iron（Ⅲ） and total iron. The present methods have the advantages of high sensitivity, low cost reagent, low operation cost, simplicity, speed and their applications for determination of iron（Ⅱ） and iron（Ⅲ） in some serum samples of normal human and fl-thalasemia patients in Erbil city. For the first time especially in Erbil city attempts were made to use zero, first and second derivative spectra to identify the serum samples of some β-thallasemia patients from the normal human serum samples due to the appearance and resolution of peaks in both cases.
基金This work wass supported by the National Natural Science Foundation of China （No.20675074 and No.10575099）.
文摘A novel analysis approach using atomic fluorescence excited by synchrotron radiation is presented. A system for synchrotron radiation-atomic fluorescence spectrometry is developed, and experimental conditions such as flow rate, analyte acidity, concentration of pre-reducing and hydrogenation system are optimized. The proposed method is successfully applied to get an excitation spectrum of arsenic. Seven of ten primary spectral lines, four of which have never been reported by means of atomic fluorescence spectrometry, agree well with the existing reports. The other three are proposed for the first time. Excitation potentials and possible transitions are investigated. Especially for the prominent line at 234.99 nm, the mechanism of generation is discussed and a model of energy transition processes is proposed.
基金ACKNOWLEDGMENTS This work was supported by the ＂Western Light＂ Visiting Scholar Plan, the Program for New Century Excellent Talents in University （No.NCET-12-1017）, the Program for Grassland Excellent Talents of Inner Mongolia Autonomous Region, the Inner Mengolia Science Technology Plan, the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region （No.NJYT-12-B13）, the Natural Science Foundation of Inner Mongolia Autonomous Region （No.2011BS0601, China）, the Inner Mongolia Talented People Development Fund, and Yongfeng Boyuan Industry Co., Ltd. Jiangxi Province, China.
文摘Cerium （III） tetraphenylporphyrin nitrate Ce（TPP）NO3 was synthesized by using meso- tetraphenylporphyrin （TPP） and Ce（NO3）.6H20 in mixture solution of CHC13 and C2HsOH （V：V=1：1）. The complex was characterized by UV-Vis, FT-IR, conventional fluorescence, MALDI-TOF-MS, and ^1H NMR spectral techniques. The structure of complex was proposed viaSpectral analyses, in which tetraphenylporphyrin was coordinated to a cerium ion in a tetradentate fashion, while one nitrate was coordinated to the same cerium ion. After bubbling NO to the solution of Ce（TPP）NO3 in CH2Cl2, spectral analyses suggested that Ce（TPP）NO3 could interact with NO to form a novel complex of Ce（TPP）（NO）NO3, and NO was coordinated to the center cerium ion. When nitrogen was poured into the Ce（TPP）（NO）（NO3） solution, the complex could be reduced to Ce（TPP）NO3.
基金National Natural Science Foundation of China (Grant No. 82003953)China Postdoctoral Science Foundation (Grant No. 2019M662278)+2 种基金Science and Technology Project of Education Department of Jiangxi Province (Grant No. GJJ190688, GJJ201252)Po stdoctoral Science Foundation of Jiangxi Province (Grant No. 2019KY42)Key Scientific Research Foundation of Jiangxi University of Traditional Chinese Medicine (Grant No. 2004/538200010402)。
文摘The encapsulation of essential oil components in cyclodextrins(CDs)to form inclusion complexes(ICs)is an effective strategy for improving their stability and bioaccessibility.The aim of the present study was to obtain a deeper understanding of the encapsulation behavior of multi-components inβ-CD.Guest molecules ofα-pinene,myrcene,and 3-carene,having the same molecular weight,formed ICs withβ-CD by a freeze-drying method.A simplex lattice mixture design with 28 experiments was carried out.Statistical analysis was applied to analyze the encapsulation behavior of guest components,and quantitative models of guest components in ICs were constructed by coupling with near-infrared(NIR)spectroscopy and chemometrics analysis.Besides,the molecular docking technique was used to obtain the optimal conformation and explain the binding behavior of inclusion.The results suggested that the spatial structure and ratio of guest molecules were the key factors affecting the encapsulation effect.A non-destructive and rapid NIR analytical model for the guest component in ICs could be obtained by second derivative(2nd der)pretreatment.Collectively,the encapsulation of guest components inβ-CD was differentiated,and NIR could be used as a rapid and non-destructive tool for quantitative analysis of ICs.
文摘We investigate nanorod assemblies of two 64-substituted pentacenes, namely （2,3-X2-9,10-Y2）-substituted pentacenes with X -- Y = OCH3 （MOP） and with X = F, Y-- OCH3 （MOPF）, grown on Au（111） single crystals. By using a multi-technique approach based on ultraviolet photoelectron spectroscopy X-ray photoelectron spectroscopy; and X-ray absorption, we find evidence for charge transfer screening at the interface with gold. Furthermore, the MOP and MOPF nanorods show a rough surface morphology, which was investigated with atomic force microscopy. We use molecular simulation techniques to investigate the energetic barriers to diffusion and to traverse step-edges to estimate their influence on the nanorod roughness. We find that barriers to surface diffusion on a terrace are anisotropic and that their direction favors the formation of nanorods in these materials.
