In-Situ FT-IR Investigation Methane to Syngas over of Partial Oxidation of Rh/SiO2 Catalyst

Partial oxidation of methane to syngas （POM） over Rh/SiO2 catalyst was investigated using in-situ FT-IR. When methane interacted with 1.0wt%Rh/SiO2 catalyst, it was dissociated to adsorbed hydrogen and CHx species. The adsorbed hydrogen atoms were transferred to SiO2 surface by ＂spill-over＂ and reacted with lattice oxygen to form surface -OH species. POM mechanism was investigated over Rh/SiO2 catalyst using in-situ FT-IR. It was found that CO2 was formed before CO could be detected when CH4 and O2 were introduced over the preoxidized Rh/SiO2 catalyst, whereas CO was detected before CO2 was formed over the prereduced Rh/SiO2 catalyst.

Investigation on the Ammonia Sensitivity Mechanism of Conducting Polymer Polypyrroles Using <i>In-Situ</i>FT-IR

Ammonia is toxic, colorless, and harmful to human health. It is important to detect ammonia effectively by gas sensors. In this paper, the mechanism of ammonia sensing on polypyrroles (PPy) films at room temperature has been investigated using a real-time, in-situ Fourier-transform infrared (FT-IR) spectroscopy. The introduction of ammonia results in a structural transformation of PPy films, which is confirmed by FT-IR spectrums. The structure and morphology of the products after the reaction between ammonia and PPy were investigated in detail by FT-IR spectrum and scanning electron microscope (SEM). It was found that the morphology of PPy films was changed to some degree after the reaction. Our results demonstrate that FT-IR spectroscopy is an extremely suitable technique for the characterization of the specific reaction between PPy and ammonia, since it allows monitoring the reaction at room temperature in real time. After the reaction between PPy and ammonia, the concentration of the carrier increases, and the resistance of PPy films decreases, indicating the sensitivity of detection of ammonia.

Synthesis and Infrared Spectra Computation of Sterically Congested 2,2-Disubstituted Indane-1,3-dione Derivatives

Sterically congested 2,2-disubstituted indane-1,3-dione derivatives have been syn-thesized and characterized by 1H NMR,13C NMR,FT-IR and elemental analysis.The B3LYP/HF calculations for computation of IR spectra have been carried out for the title compounds at the 6-31G and 6-311＋＋G basis set levels.Predicted vibrational frequencies have been assigned and compared with the experimental FT-IR spectra and they are supported each other.

Improving the activity of electrochemical reduction of CO_(2) to C_(1) products by oxidation derived copper catalyst

Cu-based electrocatalysts have become the focus in the field of electrochemical CO_(2) reduction reaction(ECO_(2) RR)due to their ability to produce multicarbon products.However,the research on generating single carbon products with higher economic feasibility via ECO_(2) RR based on Cu-based electrocatalysts is rather rare,and the roles of the surface architecture and oxides of the electrocatalysts have not been explained exactly.In this work,a two-step method including thermal oxidation and electroreduction is proposed to introduce Cuþinto pure Cu foil to form Cu_(2)O/Cu electrocatalyst.By regulating the surface composition and morphology of the electrocatalyst in this way,the activity of ECO 2 RR to C_(1) products has been greatly improved.The Faradaic efficiency of carbon products of the Cu_(2)O/Cu electrode reaches 84%at?0.7 V vs.RHE with good selectivity for HCOOH and CO.The current density of Cu_(2)O/Cu electrode reaches-12.21 mA cm^(2) at-0.8 V vs.RHE,which is much higher than that of the Cu foil electrode(?0.09 mA cm?2).In-situ Raman characterization shows that Cuþin Cu_(2)O/Cu electrode could inhibit hydrogen generation and promote ECO_(2) RR by stabilizing the adsorption of CO_(2).

Multi-spectroscopic characterization of bovine serum albumin upon interaction with atomoxetine

The quenching interaction of atomoxetine(ATX) with bovine serum albumin(BSA) was studied in vitro under optimal physiological condition(pH=7.4) by multi-spectroscopic techniques. The mechanism of ATX-BSA system was a dynamic quenching process and was confirmed by the fluorescence spectra and lifetime measurements. The number of binding sites, binding constants and other binding characteristics were computed. Thermodynamic parameters ΔH^0 and ΔS^0 indicated that intermolecular hydrophobic forces predominantly stabilized the drug-protein system. The average binding distance between BSA and ATX was studied by F?rsters theory. UV-absorption, Fourier transform infrared spectroscopy(FT-IR), circular dichroism(CD), synchronous spectra and three-dimensional(3D) fluorescence spectral results revealed the changes in micro-environment of secondary structure of protein upon the interaction with ATX. Displacement of site probes and the effects of some common metal ions on the binding of ATX with BSA interaction were also studied.

Comparison of vibrations induced by excavation of deep-buried cavern and open pit with method of bench blasting

The measured data of vibrations induced by excavation of deep-buried cavern and open pit with method of bench blasting were analyzed by Fourier Transform and Wavelet Transform,and the characteristics of vibrations induced under these two circumstances were studied.It is concluded that with the similar rock condition and drilling-blasting parameters,vibration induced by bench blasting in deep-buried cavern has a higher main frequency and more scattered energy distribution than that in open pit.The vibration induced by bench blasting in open pit is mainly originated from the blast load,while the vibration induced by bench blasting in deep-buried cavern is the superposition of vibrations induced by blast load and transient release of in-situ stress.The vibration induced by transient release of in-situ stress increases with the stress level.

Atmospheric air dielectric barrier discharge excited by nanosecond pulse and AC used for improving the hydrophilicity of aramid fibers

In this paper, a long line-shape dielectric barrier discharge excited by a nanosecond pulse and AC is generated in atmospheric air for the purpose of discussing the uniformity, stability and ability of aramid fiber treatment. The discharge images, waveforms of current and voltage,optical emission spectra, and gas temperatures of both discharges are compared. It is found that nanosecond pulsed discharge has a more uniform discharge morphology, higher energy efficiency and lower gas temperature, which indicates that nanosecond pulsed discharge is more suitable for surface modification. To reduce the water contact angle from 96° to about 60°, the energy cost is only about 1/7 compared with AC discharge. Scanning electron microscopy,Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy are employed to understand the mechanisms of hydrophilicity improvement.

The Impact of Clay Loading on the Relative Intercalation of Poly(Vinyl Alcohol)-Clay Composites

Polymer clay nanocomposites (PCN) materials are industrially applied because of their unique properties. However many of their physical and chemical properties have not been determined. The formed structures of polymer/clay nanocomposite depend on the nature of interactions between polymer chains and clay platelets. According to the possible modes of interactions between polymer matrix and clay sheets, these nanocomposites can be classified into: intercalated, flocculated and exfoliated nanocomposites. In this work, the morphology of the nanocomposite was studied using X-ray diffraction (XRD) and nanoscaning electron microscopy (NSEM). XRD and NSEM measurements confirmed the intercalation between poly(vinyl alcohol) chains and cloisite&reg;20A sheets. Because of the intercalation between the clay platelets and the PVA chains, as the clay concentration increases as the band intensities in FT-IR spectra increase. On the other hand, the XRD did not provide clear shift of any of the clay peaks for PVA/cloisite&reg; 10A nanocomposites and confirm the non-intercalation between PVA matrix and cloisite&reg;10A platelets. The relative intercalation (RI) of PVA/Cloisite&reg;20A nanocomposites declined with increase in the clay loadings. In contrast, for PVA/Cloisite&reg;10A, RI values slightly increased with increasing the clay loading.

INVESTIGATIONS OF FT-IR SPECTRA OF IRON(Ⅲ) MONONUCLEOTIDE COMPOUNDS

The interactions between ferric ion and various nucleotides are no doubt very important in the fate of iron in vivo, especially in the process of iron absorption and transportation, as well as to seek potential drugs in the treatment of iron-deficiency anemia.

STUDIES ON THE INITIATION MECHANISM OF CERIC ION AND ACETYLACETONE REDOX SYSTEM IN VINYL POLYMERIZATION

The initiation mechanism of acrylamide (AAM)polymerization using ceric ion/acetylacetone system as an initiator has been studied. The redox polymerization was revealed by the low value of overall activation energy of AAm polymerization. The structure of free radicals formed from above-mentioned initiation sytem were detected by radical trapping and ESR spectra techniques and the end groups of polymers obtained were determined by FT-IR spectra analysis method. Based on these results the initiation mechanism is proposed.

Preparation of Water Soluble Yeast Glucan by Four Kinds of Solubilizing Processes

(1→3)-β-D-glucan?from the inner cell wall of Saccharomyces cerevisiae is considered a member of a class of drugs known as biological response modifiers (BRM). However the glucan was an insoluble polysaccharide, which could be the major barrier to the utilization of glucan. In this case, the insoluble glucan was convent into a soluble form by four kind of solubilizing processes. The yield, solubility, chemistry structure and immunoprophylaxis efficacy of the soluble products were compared. Our date suggest that urea has a significant effect on yield, and DMSO has a significant effect on solubility. FT-IR spectra, 13C NMR spectra and helix-coil transition analysis demonstrate that the chemistry structure of native and solubilizing glucans have no significant difference. They still have the triple helical structure. The solubility and immunoprophylaxis efficacy assay indicate that the introduction of phosphate group not only enhanced the solubility of glucan, but also improved the survival rate of mice challenged with E. coli.

In-situ Fourier transform Raman scattering from a triple Helix DNA

A third pyrimidine strand can bind the complementary purine strand of homopurinehomopyrimidine tracts of duplex DNA to form a local triplex structure. Recently investigations have indicated that triplex-forming-oligonucleotides can specifically inhibit gene transcription in vitro and in vivo, and can be used in chromosome analysis and

Low-coordinated Ni-N_(1)-C_(3)sites atomically dispersed on hollow carbon nanotubes for efficient CO_(2)reduction

Low-coordinated single atom catalysts compared to M-N4 are appealing in optimized electronic structure for CO_(2)electroreduction,but the preparation is still very challenging.Herein,a novel single Ni atom catalyst with Ni-N_(1)-C_(3)configuration is in-situ evolved on curved carbon nanotubes.The obtained Ni-N_(1)-C_(3)catalyst exhibits a superior CO Faradaic efficiency of 97%and turnover frequency of 2,890 h^(−1)at−0.9 V versus the reversible hydrogen electrode,as well as long-term stability over 45 h.High current densities exceeding 200 mA·cm^(−2)and CO Faradaic efficiency of 99%are achieved in flow-cell.Moreover,in-situ potentialand time-dependent Raman spectra identify the key intermediates of*COOH and*CO during CO_(2)-to-CO conversion.Theoretical calculations reveal that the upward-shifted d-band center and charge-rich Ni sites of Ni-N_(1)-C_(3)facilitate the electron transfer to*COOH and thus reduce the*COOH formation energy barrier.This work demonstrates a strategy for modulating the coordination environment for efficient CO_(2)reduction.

Numerical evaluation of the effectiveness of NO_2 and N_2O_5 generation during the NO ozonation process

Wet scrubbing combined with ozone oxidation has become a promising technology for simultaneous removal of SO_2 and NO_x in exhaust gas.In this paper,a new 20-species,76-step detailed kinetic mechanism was proposed between O_3 and NO_x.The concentration of N_2O_5 was measured using an in-situ IR spectrometer.The numerical evaluation results kept good pace with both the public experiment results and our experiment results.Key reaction parameters for the generation of NO_2 and N_2O_5 during the NO ozonation process were investigated by a numerical simulation method.The effect of temperature on producing NO_2 was found to be negligible.To produce NO_2,the optimal residence time was1.25 sec and the molar ratio of O_3/NO about 1.For the generation of N_2O_5,the residence time should be about 8 sec while the temperature of the exhaust gas should be strictly controlled and the molar ratio of O_3/NO about 1.75.This study provided detailed investigations on the reaction parameters of ozonation of NO_x by a numerical simulation method,and the results obtained should be helpful for the design and optimization of ozone oxidation combined with the wet flue gas desulfurization methods（WFGD） method for the removal of NO_x.

Spectrofluorimetric Study on the Weak Interaction between ATP and Na-4-Tosyl-L-arginine Methyl Ester Hydrochloride

In this paper, some new results on the selective weak interaction between Na-4-tosyl-L-arginine methyl ester hydrochloride （TAME） and adenosine-5＇-triphosphate （ATP） have been reported. Fluorescence spectrophotometry and Fourier transform infrared （FT-IR） spectroscopy were used to investigate this kind of weak interaction. In fluorescence experiments, obvious fluorescence quenching phenomena were observed when TAME was added, which indicated the weak interactions between TAME and ATP. It has been identified by fluorescence titration experiments that TAME exhibited high selectivity to ATP over ADP and AMP. FT-IR spectral results showed that an ATP-TAME adduct was formed. The experimental results indicated that the interaction sites were the guanidinium group of TAME main-chain and the γ-phosphate group of ATP, and the interaction took place through hydrogen bonding and electrostatic force. In addition, the effects of metal ions on the weak interaction between ATP and TAME, or between ATP and analogues of L-arginine were studied.

Synthesis of Asymmetrical Monobenzo-Substituted Cobalt Thioporphyrazines and Their Biomimetic Catalytic Property

Two novel monobenzo porphyrazines bearing nitro and methoxyl respectively on fused benzene ring were suc- cessfully synthesized. Also, an asymmetrical porphyrazine with one butylthio branch at the pyrrolic p-position sub- stituted by hydrogen atom was successfully isolated in the course of synthesis of symmetric octakis（butylthio） porphyrazine. Their corresponding cobalt complexes were subsequently obtained and characterized. Their catalytic ability was assessed by aerobic oxidation of benzoin, showing the highest benzil yield of 95.2% for 60 min. A pos- sible mechanism was also presented from the in-situ UV-Vis spectra, in which a novel and characteristic absorption peak of metal-oxo was observed. At the same time, similar results of the extended oxidation of benzyl alcohol also confirmed the reactive mechanism.