Study on Catalytic Wet Oxidation of H2S into Sulfur on Fe/Cu Catalyst

A wet catalytic oxidation at room temperature was investigated with solution containing ferric, ferrous and cupric ions for H2S removal. The experiments were carried out in a two step process, and the results obtained show that the removal efficiency of H2S can always reach 100% in a 300 mm scrubbing column with four sieve plates, and the regeneration of ferric ions in 200 mm bubble column can match the consumed ferric species in absorption. Removal of H2S, production of elemental sulfur and regeneration of ferric, cupric ions can all be accomplished at the same time. No raw material is consumed except O2 in flue gas or air, the process has no secondary pollution and no problem of catalyst degradation and congestion.     

Charge transfer across the water/nitrobenzene interface by three-electrode system

A droplet of aqueous solution containing a certain molar ratio of redox couple is first attached onto a platinum electrode surface, then the resulting drop electrode is immersed into the organic solution containing very hydrophobic electrolyte. Combined with reference and counter electrodes, a classical three-electrode system has been constructed. Ion transfer (IT) and electron transfer (ET) are investigated systematically using three-electrode voltammetry. Potassium ion transfer and electron transfer between potassium ferricyanide in the aqueous phase and ferrocene in nitrobenzene are observed with potassium ferricyanide/potassium ferrocyanide as the redox couple. Meanwhile, the transfer reactions of lithium, sodium, potassium, proton and ammonium ions are obtained with ferric sulfate/ferrous sulfate as the redox couple. The formal transfer potentials and the standard Gibbs transfer energy of these ions are evaluated and consistent with the results obtained by a four-electrode system and other methods.     

Effects of Magnesium and Ferric Ions on Crystallization of Calcium Sulfate Dihydrate Under the Simulated Conditions of Wet Flue-gas Desulfurization

The influences of magnesium and ferric ions in their different ratios on the rate of gypsum crystallization were studied under the conditions similar to those of wet flue-gas desulfurization（WFGD）. The results show that addition of both Mg^2＋ and Fe^3＋ increased induction time and decreased the growth efficiency up to 50% compared with the baseline（without impurities） depending on the concentration and the type of impurity. The effects of Mg^2＋ and Fe^3＋ on the surface energy and the rate of nucleation were estimated by employing the classical nucleation theory. The surface energy decreased by 8% and 14% with the addition of 0.02 mol/L magnesium or ferric ions, respectively, compared to the baseline. Mg^2＋ and Fe^3＋ made the growth rate of the （020）, （021） and （040） faces of gypsum crystal a much greater reduction, which leads to the formation of needle crystals compared to the baseline which favors the formation of plate or flakes. Furthermore, an edge detection program was developed to quantify the effects of impurities on the filtration rate of gypsum product. The results show that the inhibition efficiency of the presence of 0.02 mol/L Mg^2＋ and Fe^3＋ on the filtration rate of gypsum crystal ranges from 22% to 39%.     

Amino acid identification and sequence analysis of peptides by reaction mass spectrometry

Fast atom bombardment mass spectrometry (FAB-MS) is applied to distinguish N-terminal series ions from C-terminal series ions of a peptide by on-probe acetylation, it providesvaluable information about the sequence of an unknown peptide. The FAB mass spectra containa number of characteristic ions at low-mass region in addition to the sequence ions at high-massregion. It was found that the ions below m/z 200 are characteristic of the amino acid composition ofthe peptide, from which the amino acid composition of the peptide could be estimated. Additionally,mixture analysis is also discussed.     

Recent advances in click-derived macrocycles for ions recognition

Triazole-containing macrocycles using Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition click reaction for ions recognition, including anions, metal ions and ions pair, have been reviewed.     

Studies on the Synthesis and the Structure of Ferric Aluminum Magnesium Hydrotalcite—like Compounds

Hydrotalcite-like compounds (HTlc) are composed of trivalent and divalent metal ions, the general formula 1 is: [M2+1-xM3+x(OH)2]x+An-x/n·mH2O M3+ is trivalent metal ions, M2+is divalent metal ions, A is negative ions whose valence is n, and m is the amount of water in the crystal, and x is the molar ratio of trivalent metal ions to all metal ions. A lot of studies have been done on the synthesis and property of HTlc, which is made up of two kinds of the metal ions. It has been found …     

Acyl Thioacetamide-group Chelated Nanofiber to Adsorb Silver Ions from Aqueous Systems

The acyl thioacetamide-group chelated nanofiber was prepared from polyacrylonitrile（PAN） fiber with thioacetamide as vulcanization agent by an electrospinning process combined with chemical modification.It was found that the chelated nanofiber displays a high adsorption capacity and adsorption selectivity for Ag（Ⅰ） ions from aqueous systems.The adsorption capacity of Ag（Ⅰ） ions on chelated nanofiber increases with the increase of adsorption time.Kinetics of the Ag（Ⅰ） ions adsorption was found to follow pseudo-second-order rate equation.Based on the characterization results,a possible mechanism of Ag（Ⅰ） ions adsorbed on the acyl thioacetamide-group chelated nanofiber was proposed.The chelated nanofiber could not only chelate to Ag（Ⅰ） ions but also reduce them.This study provides a promising nanofiber material for removing heavy metal ions.     

Preparation and Luminescence Behavior of CaSiO3:Eu3+(Bi3+)

CaSiO3:Eu3 0.08Bi3 0.002 with a monoclinic perovskite structure was synthesized by using sol-gel method, and its luminescence characteristics were investigated. From the excitation spectrum, it can be seen that the main peaks located at238, 396, 415, 437 and 359 nm correspond to the charge-transfer band of Eu3 -O2- , the absorption transitions of 7F0,1→5 L6,7F0→5D3,7F1→5D3 of Eu3 ions, and 3P1→1S0 of Bi3 ions, respectively. When the samples were excited with a light of wavelength 359 or 395 nm, it can be seen from the emission spectrum that the electronic dipole transition located at 609 nm corresponding to 5D0 →7F2 of Eu3 ions was stronger than the magnetic dipole transition located at 587 nm corresponding to 5D0→7F1 of Eu3 ions, which shows that more Eu3 ions were located in nonreversion center lattices. The energy transfer from Bi3 ions to Eu3 ions in the phosphor was also discussed. The results show that Eu3 ions could be well sensitized by Bi3 ions, and the energy-transfer pattern between Bi3 ions and Eu3 ions was resonance energy transfer.     

Preparation and Luminescence Behavior of CaSiO3：Eu^3＋（Bi^3＋）

CaSiO3：Eu0.08^3＋Bi0.002^3＋ with a monoclinic perovskite structure was synthesized by using sol-gel method, and its luminescence characteristics were investigated. From the excitation spectrum, it can be seen that the main peaks located at 238,396,415,437 and 359 nm correspond to the charge-transfer band of Eu^3＋-O^2- , the absorption transitions of ^7F0.1→^3L6, ^7F0→^5D3, ^7F1→^5D3 of Eu^3＋ ions, and ^3P1→^1S0 of Bi^3＋ ions, respectively. When the samples were excited with a light of wavelength 359 or 395 nm, it can be seen from the emission spectrum that the electronic dipole transition located at 609 nm corresponding to ^5D0→^7F2 of Eu^3＋ ions was stronger than the magnetic dipole transition located at 587 nm corresponding to ^5D0→^7F1 of Eu^3＋ ions, which shows that more Eu^3＋ ions were located in nonreversion center lattices. The energy transfer from Bi^3＋ ions to Eu^3＋ ions in the phosphor was also discussed. The results show that Eu^3＋ ions could be well sensitized by ^3＋ions, and the energy-transfer pattern between Bi^3＋ ions and Eu^3＋ ions was resonance energy transfer.     

Multi-bond network hydrogels with robust mechanical and self-healable properties

Multi-bond network(MBN) which contains a single network with hierarchical cross-links is a suggested way to fabricate robust hydrogels. In order to reveal the roles of different cross-links with hierarchical bond energy in the MBN, here we fabricate poly(acrylic acid) physical hydrogels with dual bond network composed of ionic cross-links between carboxylFe3+ interactions and hydrogen bonds, and compare these dually cross-linked hydrogels with singly and ternarily cross-linked hydrogels. Simple models are employed to predict the tensile property, and the results confirm that the multi-bond network with hierarchical distribution in the bond energy of cross-links endows hydrogel with effective energy-dissipating mechanism. Moreover, the dually cross-linked MBN gels exhibit excellent mechanical properties(tensile strength up to 500 k Pa, elongation at break ~ 2400%) and complete self-healing after being kept at 50 °C for 48 h. The factors on promoting self-healing are deeply explored and the dynamic multi-bonds are regarded to trigger the self-healing along with the mutual diffusion of long polymer chains and ferric ions.     

Copper-exchanged LTA zeolite membranes with enhanced water flux for ethanol dehydration

Phase-pure and well-intergrown Cu-LTA membranes are developed through copper ions exchange of sodium ions in Na-LTA framework. For pervaporation of 90.0 wt% ethanol/10.0 wt% water mixtures, the Cu-LTA membrane shows much higher water flux than Na-LTA membranes due to the enhancement of the pore size after ions exchange.     

FT-Raman Spectroscopic Studies on the Interaction of Metal Ions With Sphingomyelin Bilayer

The interaction of trivalent lanthanide ions and divalent calcium ions with sph-'ngomyelm bilayer has been studied by FT-Raman spectroscopy.The results showed that the bonding of metal ions to the phosphate group of sphingomyelin bi-iayer,either La3 or Ca2 did not change the conformation of the choline group,that is,O-C-C-N is still in its gauche conformation.The presence of metal ions changed the states of the interfacial region from liquid-like to amorphous state and even to crystalline.They increased the fluidity of acyl chains of sphingomyelin bilaver and made them packed disorderly.     

Synthesis of novel calix[4]crown telomers and selective extraction of cesium ions

p-tert-Butylcalix[4]diazacrown-4 telomer, which contains hard and soft ion binding sites, was synthesized. It exhibited high selectivity toward cesium ions. The binding sites may complex alkali metal ions selectively.     

Magnetism tuned by intercalation of various metal ions in coordination polymer

Insertion of various metal ions have changed the ferromagnetic coordination frameworks into paramagnetic, superparamagnetic, or ferromagnetic. The net charge and radius of the ions determined the magnetism of the host frameworks.     

Dynamic dispersion stability of graphene oxide with metal ions

Graphene oxide(GO),an important chemical precursor of graphene,can stably disperse in aqueous surrounding and undergo aggregation as metal cations introduced.The usual instability of GO with ions is caused by the shielding effect of ions and crosslinking between GO and ions.However,the dynamic stability of GO under ions exchange still remains unclear.Here,we investigated the dynamic dispersion stability of GO with metal ions and observed a redispersion behavior in concentrated Fe~(3+) solution,other than permanent aggregation.The exchange with Fe~(3+) ions drives the reversion of zeta(ζ) potential and enables the redispersion to individual GO-Fe~(3+) complex sheets,following a dynamic electric double layer(EDL) mechanism.It is found that the specifically strong electrostatic shielding effect and coordination attraction between Fe~(3+) and functional oxygen groups allows the selective redispersion of GO in concentrated Fe~(3+) solution.The revealed dynamic dispersion stability complements our understanding on the dispersive stability of GO and can be utilized to fabricate graphene-metal hybrids for rich applications.     

Reactions of Laser Ablation-magnesium Plasma with Methanol Clusters

IntroductionReactions of metal ions with neutral molecules orclusters produce a variety of metal complex ions andother new series of cluster ions including cations andanions.The laser ablation-molecular beam(LA-MB)method has marked its relevance in the st…     

Hydrogen Evolution Reaction on Thermodiffusion Treated Nickel-Implanted Titanium Electrodes

Implating ions with high-energy into the surface of electrode can introduce catalytically active elements, and thus form a large number of active centers to improve the catalytical activity. As a result of implanting nickel ions into Ti-electrode we get a overpotential decrease of hydrogen evolution by 245 mV and the electrode was much more active than the unimplanted one. The experiment shows that the catalytical activity of the electrodes raises with the increase of the surface nickel ions concentration. The maximum concentration of ions were not on the electrode surface, as the deep distribution of the     

Promoter Effects of Rare Earth Ions on Electrocatalytic Oxidation of Methanol

The promoter effects of rare earth ions on the electrocatalytic oxidation of methanol at the Pt electrode were studied using the cyclinc voltammetry and stable polarization techniques. It was found or the first time that Eu、Ho、Dy ions could accelerate the electrocatalytic oxidation of methanol at the Pt electrode,while Lu、Pr、Yb、Sm ions showed inhibitor effects.     

Nitrogen-doped Carbon Dots: Application of Hg Ions Detection in Rannasangpei

Nitrogen-doped carbon dots(N-CDs) were hydrothermally synthesized by folic acid, which revealed excited wavelengtli-dependent blue emission and the specific recognition ofHg ions by fluorescence quenching. A wide range response and a fitted linear relationsliip for Hg ions detection were established to show that tliese blue-emission N-CDs achieved a satisfying Hg ions detection in Chinese traditional herb, Rannasaiigpei(RSNP). Tlie results from the N-CDs FL quenching gave the similar outcomes with those from ICP-OES measurement, which exhibited the possibility of the simple FL method of Hg ions detection by N-CDs in Chinese traditional herbs.     

Microcalorimetric Study of the Action of Yb^3＋ ion on the Growth of Staphylococcus aureus

A microcalorimetric method was used to evaluate the action of Yb^3 ions onthe growth metabolism of Staphylococcus aureus.The power-time curves of the growth metabolism of Staphylo.coccus aureus and the action of Yb^3 ions were obtained by us-ing stopped-flow method at 37 ℃. For evaluation of the action,the growth rate constants ( k1 and k2) for the log phase 1, log phase 2, and the total heat effect (Qtotal) for Staphylococcus aureus were determined. The results show that Yb^3 ions at low concentrations have the stimnlatory effect on Staphylococcus au-reus and that Yb^3 ions at higher concentration could inhibit its growth.