傅里叶变换拉曼光谱法鉴别肉桂及其混淆品阴香

目的:无损快速鉴别肉桂及其混淆品阴香。方法:采用傅里叶变换拉曼光谱法(FT-Raman)。结果:肉桂与其混淆品阴香在拉曼谱图中均有各自的特征峰,可容易地将它们区别开。结论:该方法具有快速、准确、操作简单、不需对样品进行提取分离,可直接进行测定的特点。

傅里叶变换拉曼光谱法鉴别八角茴香及其伪品

目的 :鉴别八角茴香及其伪品。方法 :傅里叶拉曼光谱法 ( FT-Ram an)。结果 :八角茴香及其伪品在拉曼光谱中均有各自的特征峰 ,极易将它们区别开。结论 :该方法快速准确 ,操作简单 ,不需分离 ,可直接测定。

FT-Raman光谱法无损鉴定药材的真伪

本文利用傅里叶变换拉曼 (FT Raman)光谱法无损快速鉴定了正品大黄与伪品大黄以及有掺伪物的知母样品。结果表明 :大黄 (西宁大黄 )与伪品大黄 (华北大黄、山大黄、水根大黄 )在拉曼谱图中均有各自的特征峰 ,可容易地将它们区别开 ;知母样品中所掺杂的其他饮片 ,经与白芨的拉曼谱图比对 ,证实为白芨饮片。该方法具有快速、准确、操作简单、不需对样品进行提取分离 ,可直接进行测定的特点。

药用植物真伪品的FT-Raman光谱法鉴别研究

首次采用近红外傅里叶变换拉曼光谱法 (NIR Raman)无损快速鉴别了药用植物肉桂、天麻及其伪(混淆 )品。结果表明 :药用植物肉桂、天麻及其伪 (混淆 )品在拉曼光谱图上有明显的差别。如肉桂在 1 60 0和 1 3 0 0cm- 1有较特征的基频振动峰 ,而肉桂的混淆品阴香 1 3 3 0cm- 1的峰较弱 ,相反的是 1 62 4和 1 5 97cm- 1的基频振动峰较强。天麻在 2 91 4cm- 1的C H振动峰与羊角天麻的 2 93 4cm- 1位移了 2 0个波数 ,另外羊角天麻在 1 60 5cm- 1有较强的拉曼基频振动峰 ,而药用天麻此处未见振动峰。凭借这些谱峰的差异可进行药材的真伪鉴别。该方法具有快速、准确、操作简单、不破坏样品 ,可直接进行鉴别的特点。

抗坏血酸恒温氧化过程拉曼光谱的二维相关分析

采用近红外傅里叶变换拉曼光谱法 (NIRFT -Raman)和二维相关分析 (2DCorrela tionAnalysis)技术研究了固态抗坏血酸的恒温 (1 0 0℃ )氧化过程。研究表明 ,二维相关分析能提供氧化扰动过程中结构动态变化的微观信息 。

不同产地藿香的红外光谱分析

目的建立红外光谱技术,快速鉴别不同产地藿香的方法。方法采用傅里叶变换红外光谱技术和二维相关红外光谱法鉴定石牌广藿香(牌香),高要广藿香(肇香),海南广藿香(南香),湛江广藿香(湛香)等四种药材。结果四种不同产地的广霍香(南香、湛香、牌香、肇香)的一维红外光谱和高分辨的二阶导数谱的结果相一致,确切地佐证了南香药材与其它三个产地药材相比具有明显的差异性,很好地解释了南香属于广藿香伪品的论证。二维红外相关谱表明:肇香在940 cm-1的自动峰最强,而牌香和湛香在947 cm-1为最强峰,两者相差了7个波数。湛香1151 cm-1的自动峰明显强于牌香的自动峰,另外湛香947 cm-1的交叉峰也明显强于牌香的交叉峰。凭借自动峰和交叉峰的强弱既可以作为鉴别相似度较大的牌香和湛香的依据。结论红外光谱、二阶导数谱和二维相关红外光谱等三谱技术可以相互补充,相互佐证,可以鉴别四种广藿香的产地,同时也可以看到肇香与牌香、湛香的品质相近,但不完全相同,品质最差的是南香,即海南产的广藿香。

昆明山海棠与南蛇藤红外宏观指纹图谱研究

比较了卫矛科的昆明山海棠和南蛇藤粉末和醇提物的红外图谱特征。两种药材的粉末图中都看到草酸钙和淀粉的特征。醇提物图中都有卫矛醇的特征,但南蛇藤较为明显。两种药材醇提物的二阶导数图有明显差异,说明某些成分含量不同。南蛇藤根图的草酸钙和卫矛醇的峰形都比茎的强和尖,说明其根中草酸钙和卫矛醇的含量比茎大。由于红外法既能快速地找出药材差异,又能准确指认出卫矛醇,所以此法制定的宏观指纹图谱可作为生药鉴定的依据。

各种水泥助磨剂的特性及对水泥易磨性与性能的影响

这里研究工作的目的是评价用于硅酸盐水泥（实验室阶段在一个球磨机中研磨）生产的六种商业助磨剂。为了参考，一个样品没有添加任何附加剂进行粉磨。利用傅里叶变换红外光谱法和气相色谱／质谱联用技术对助磨剂的特性进行了描述。粉磨后的水泥试样测试初凝和终凝时间、标准稠度用水量、流动性，以及在2d、7d、28d后测试抗压强度。实验过程中，掺加助磨剂能使物料更易被粉磨，并且改善水泥的比表面积，这个归因于添加剂不仅能降低粉碎阻力，还能阻止物料颗粒团聚与黏附在粉磨介质和磨机内壁上。水泥粉磨时加入的商业助磨剂都含有三异丙醇胺（TIPA），它能在不同龄期提高水泥强度，并且延长水泥的凝结时间。另外，商业助磨剂中三乙醇胺（TEA）的存在不但影响了生产水泥的力学性能，还略减少了水泥的凝结时间。

近红外光谱法同时快速鉴别3种麻黄药材品种

目的:建立同时快速鉴别3种药典收载麻黄药材的近红外光谱法。方法:测量药典品种麻黄药材草麻黄、中麻黄和木贼麻黄,以及混淆品种丽江麻黄的傅里叶变换近红外漫反射光谱,采用化学计量学技术,提取不同药典品种麻黄药材共有的且区别于混淆品种丽江麻黄的光谱特征信息,建立同时鉴别不同药典品种麻黄药材与混淆品种丽江麻黄的判别分析(discriminant analysis,DA)模型和对向传播人工神经网络(counterpropagation artificial neural network,CP-ANN)模型,并比较2种模型的性能。结果:所建DA模型校正集和验证集的预测准确率均为100.0%;CP-ANN模型校正集、交叉验证和验证集的预测准确率均为100.0%。虽然2种模型具有相同的预测准确率,但是非线性CP-ANN模型使用较少的主成分建模,性能略优于线性DA模型。结论:所建近红外光谱法能够同时快速鉴别3种药典收载麻黄药材。

Surface modification of ZrO_2 nanoparticles with styrene coupling agent and its effect on the corrosion behaviour of epoxy coating

The surface of ZrO2 nanoparticles was modified by styrene coupling grafting method to improve the dispersion and interaction of the nanoparticles with the epoxy coating in which the modified ZrO2 nanoparticles were used as an additive. The grafting performance and microstructure of the nano- ZrO2/epoxy coating were analyzed by Fourier transformation infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The corrosion behavior of the nano-ZrO2/epoxy coating on mild steel was evaluated in neutral 3.5 wt% NaC1 solution using electrochemical impedance spectroscopy （EIS）. Both the coating capacitance and coating resistance fitted by the equivalent circuit from EIS were used to evaluate the protective performance of the coating towards the mild steel. The results show a superior stability and efficient corrosion protection by the modified ZrO2 nanoparticles. The epoxy coating containing 2 wt% modified ZrO2 nanoparticles exhibited the best corrosion performance among all the coating specimens. This research may provide an insight into the protection of mild steel using modified epoxy coatings.

TG–FTIR analysis of pyrolusite reduction by major biomass components

Pyrolusite reduction processes by three major biomass components cellulose,hemicelluloses and lignin,represented by CP,HP and LP,respectively,were investigated by thermogravimetric analyzer coupled with Fourier transform infrared spectrometry(TG-FTIR).The Sestak-Berggren(SB) equation was used to evaluate the kinetics of reduction processes.TG analysis reveals that the main reduction processes occur at 250-410 ℃,220-390 ℃,and 190-410 ℃ for CP,HP,and LP,respectively.FT-IR and XRD results indicate that various reducing volatiles(e.g.aldehydes,furans,ketones and alcohols) are produced from the pyrolysis with the three major components,which directly reduce MnO_2 in ore to MnO.The processes are described by the SB equation with three parameters(m,n,p).Their non-zero values suggest that pyrolusite reduction is controlled by the diffusion of reducing gaseous products through an ash/inert layer associated with minerals.The apparent activation energies for pyrolusite reduction by CP,HP and LP are 40.48,25.70 and 40.10 kJ·mol^(-1),respectively.

Curing Mechanism of Condensed Polynuclear Aromatic Resin and Thermal Stability of Cured Resin

In order to improve the thermal stability of condensed polynuclear aromatic(COPNA) resin synthesized from vacuum residue, 1,4-benzenedimethanol was added to cure COPNA resin. The curing mechanism was investigated by proton nuclear magnetic resonance spectrometry, solid carbon-13 nuclear magnetic resonance spectrometry and Fourier transform infrared spectroscopy. Microstructures of the uncured and the cured COPNA resins were studied by scanning electron microscopy and X-ray diffractometry. The thermal stability of COPNA resins before and after curing was tested by thermogravimetric analysis. The element composition of the cured COPNA resin heated at different temperatures was analyzed by an element analyzer. The results showed that the uncured COPNA resin reacted with the cross-linking agent during the curing process, and the curing mechanism was confirmed to be the electrophilic substitution reaction. Compared with the uncured COPNA resin, the cured COPNA resin had a smooth surface, well-ordered and streamlined sheet structure with more crystalline solids, better molecular arrangement and orientation. The weight loss process of the uncured and cured COPNA resins was divided into three stages. Carbon residue of the cured COPNA resin was 41.65% at 600 ℃, which was much higher than 25.02% of the uncured COPNA resin, which indicated that the cured COPNA resin had higher thermal stability.

Effect and mechanism of siderite on reverse anionic flotation of quartz from hematite

Reverse flotation technology is one of the most efficient ways to improve the quality and reduce impurity of iron concentrate. Mineral processors dealing with hematite face a challenge that the flotation results of reverse flotation of hematite are poor in presence of siderite using fatty acid as collector, starch as depressant of iron minerals and calcium ion as activator of quartz at strong alkaline pH. In this work, the effect of siderite on reverse anionic flotation of quartz from hematite was investigated. The effect mechanism of siderite on reverse flotation of hematite was studied by solution chemistry, ultraviolet spectrophotometry(UV) and Fourier transform infrared spectroscopy(FTIR). It was observed that siderite had strong depressive effect on quartz in flotation using sodium oleate as collector, corn starch as depressant of iron minerals and calcium chloride as activator of quartz at strong alkaline pH. The starch was adsorbed onto calcium carbonate by chemical reaction which was formed by CO^(2-)_3 from siderite dissolution and Ca^(2+) from calcium chloride as activator of quartz and precipitated on the surface of quartz, which resulted in improving the hydrophilic ability of quartz.

Surface Modification of Polycarbonate Urethane by Covalent Linkage of Heparin with a PEG Spacer

Heparin was grafted onto polycarbonate urethane (PCU) surface via a three-step procedure utilizing α, ωdiamino-poly(ethylene glycol) (APEG, M n =2 000) as a spacer. In the first step, isocyanate functional groups were introduced onto PCU surface by the treatment of hexamethylene diisocyanate (HDI) in the presence of di-n-butyltin dilaurate (DBTDL) as a catalyst. In the second step, APEG was linked to the PCU surface to obtain the APEG conjugated PCU surface (PCU-APEG). In the third step, heparin was covalently coupled with PCU-APEG in the presence of N-hydroxysuccinimide (NHS) and 1-ethyl-3-(3-dimethylamidopropyl) carbodiimide (EDAC). The amount of heparin (1.639 μg/cm 2 ) covalently immobilized on the PCU-APEG surface was determined by the toluidine blue method. The modified surface was characterized by water contact angle, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The hemocompatibility was preliminarily studied by platelet adhesion test. The results indicated that heparin was successfully grafted onto the PCU surface, and meanwhile the hydrophilicity and hemocompatibility of the modified PCU surface were improved significantly compared with the blank PCU surface.

Growth Kinetics of Silicon Carbide Film Prepared by Heating Polystyrene/Si（111）

SiC films were prepared by heating polystyrene/Si（111） in normal pressure argon atmosphere at different temperatures. The films were investigated by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and Fourier transform infrared absorption measurements. The thicknesses of SiC films were calculated from FTIR spectra. The growth kinetics of the growth process of SiC films were investigated as well. The thicknesses of the SiC films grown for 1 h with increasing growth temperatures have different trends in the three temperature ranges： increasing slowly （1200-1250 ℃）, increasing quickly （1250- 12.70 ℃）, and decreasing （1270-1300 ℃）. The apparent activation energies of the growth process of SiC films in the three ranges were calculated to be 122.5,522.5, and -127.5 J/mol respectively. Mechanisms of the different growth processes were discussed. The relation between film thicknesses and growth temperatures indicated that the growth process was a 2D mechanism in the first range and 3D mechanism in the second range. In the third range, the thicknesses of SiC films were decreased by the volatility of Si and C atoms.

Adsorption of Chromium （VI） onto Activated Carbon Modified with KMnO4

The adsorption capacity of activated carbon modified with KMnO4 （potassium permanganate） for Cr（VI） from aqueous solution was investigated. The modified activated carbon was characterized by SEM （scanning electron microscopy）, FT-IR （Fourier transform infrared spectrometer）, and N2 adsorption/desorption tests. Adsorption of Cr（VI） from aqueous solution onto the activated carbon was investigated in a batch system. In the present study, the effect of various parameters such as pH, contact time and initial concentration on the adsorption capacity were determined by ICP-AES （inductively coupled plasma atomic emission spectrometry）. The Cr（VI） adsorption on the activated carbon conforms to the Langmuir and Freundlich isothermal adsorption equation. The rates of adsorption were found to conform to pseudo-second order kinetic. The modified activated carbon can be an effective adsorbent for Cr（VI） from the aqueous solution.

Preparation of Thermoplastic Elastomer from Polypropylene-SIR 10 Rubber Blends with Addition of Dicumil Peroxide as Initiator and Divinylbenzene as a Crosslinker

Preparation of thermoplastic elastomer of Polypropylene-SIR 10 rubber blends with addition of DCP （dicumil peroxide） as initiator and DVB （divinylbenzene） as a crosslinker has been done. Blends of Polypropylene-SIR 10 rubber with variation of weight 60/40 （w/w）, 50/50 （w/w） and 40/60 （w/w） with variation concentration of DCP and DVB 1 phr, 2 phr and 3 phr were mixed into internal mixer at temperature 180 ℃. Then, the blends were pressed at 185 ℃ and specimen were molded according to the ASTM D638. The characterization were carried out based on tensile strength testing, crosslink percentage, morphology surface analysis with SEM and fungtional group analysis with FTIR （Fourier Transform Infra Red）. The result showed that the blends of Polypropilene-SIR 10 rubber 60/40 （w/w） with 2 phr DCP and 1 phr DVB posses a higher tensile strength with value 1.37 Kgf/mm2 and value of elongation at break 17.58%, and value of percentage crosslink 82.4%. The result of morphology test with SEM showed that the blend was well homogenous. Spectra analysis with FT-IR has shown physical interaction among components of the blends.

Study of Dye Absorption in Carbon Nanotube-Titanium Dioxide Heterostructures

In this work, the authors present a study of dye absorption in TiO2 doped with CNTs （carbon nanotubes）. Absorption decreases exponentially with the increase of CNTs in the film, while morphological characterization, conducted by SEM （scanning electron microscope） and TEM （transmission electron microscope） microscopes, suggests that this behavior is strongly related to morphological structure of grown films. For CNTs amounts greater than 1%, the authors observe the formation of CNTs clusters randomly distribute on TiO2 bulk, which strongly reduces the film porosity quenching the dye absorption. Comparison with optical properties of CNT/TiO2 filmstudied in the previous work, suggest that the best level of doping is with 0.5% of CNTs. FTIR （Fourier transform infrared spectroscopy） measurements conducted on a series of pristine and doped samples clearly indicate the absence of change in allotropic species of TiO2, while AFM （atomic force microscope） analysis indicates that the sample roughness strongly changes with doping, preventing the dye adsorption. Finally, measurements of cell efficiency indicate an increase of 5% in cells with 0.5% of CNT doping and a decrease for greater values.

Study on Weathering Behavior of Jack Pine Heat-Treated under Different Conditions

It is of considerable importance to investigate the influence of weathering on the degradation processes of heat-treated wood. Kiln-dried （untreated）jack pine （Pinus banksiana） and jack pine heat-treated at three different temperatures （190 ℃, 200 ℃, and 210 ℃） were exposed to artificial weathering for different periods in order to understand the degradation processes due to weathering. Before and after exposure, their color and wettability by water were determined. Structural changes and chemical modifications at exposed surfaces were also investigated using SEM （scanning electron spectroscopy）, FTIR （Fourier transforms infrared spectroscopy）, and XPS （X-ray photoelectron spectroscopy）. The results revealed that the photo-degradation of lignin and the presence of extractives play important roles in color change and wetting behavior of heat-treated wood surfaces during weathering. The structural changes also influence the wettability. The effects of weathering for woods heat-treated under different conditions were similar, but different from those for untreated wood.

Preparation, characterization, and antifungal activity of hymexazol-linked chitosan derivatives

In this study, three hymexazol-linked chitosan derivatives （HML-CS） were synthesized and their structures confirmed by Fourier transform infrared and elemental analysis. Linkage ratios were measured by high performance liquid chromatography. The derivatives＇ antifungal activity against the plant pathogenic fimgi Rhizoctonia solani CGMCC 3.28 and Gibberella zeae CGMCC 3.42 were investigated at concentrations of 100, 200, and 400 mg/L. These HML-CS derivatives exhibited stronger antifungal activity than CS alone. HML-CS-1 showed the best antifizngal activity against G. zeae, whose antifimgal index was 65.9% at 400 mg/L, and also showed the best antifungal activity against R. solani, whose antifimgal index was 52.7% at 400 mg/L. This conjugation of CS and HML suggested the presence of synergistic effects between the moieties and indicated that these derivatives possessed great potential as novel fungicides and require further research for the development of applications in crop protection.