The genesis of H2S in the Weiyuan Gas Field, Sichuan Basin and its evidence

The Sinian Dengying Formation gas pool in Weiyuan is the oldest large-scale sulfur-bearing gas field in China, which has a H2S content ranging from 0.8% to 1.4%. The Cambrian Xixiangchi Formation gas pool discovered recently above the Dengying Formation contains gas geochemical behaviors similar to those of Dengying Formation but different in sulfur isotopes of H2S. Investigations show that though these two Sinian and Cambrian gas pools are separate ones, they share the same Cambrian source rock. The higher dry coefficient, heavier carbon isotopes, sulfur isotopes of sulfide, lower filling of gas pools, formation water characteristics, reservoir properties and H2S distribution, indicate that H2S in both the Sinian and Cambrian gas pools originates from TSR. The sulfur isotopes of sulfates have shown that H2S was formed in respective pools, namely hydrocarbons charged into the pools reacted with the Dengying Formation and the Xixiangchi Formation gypsum （TSR）, respectively, to form H2S. Compared with sulfur isotopes of sulfates in each pool, δ^34S values of H2S are 8‰ lighter for the Dengying Formation pool and 12‰ lighter for the Xixiangchi Formation pool, respectively, which is attributed to the difference in temperatures of TSR occurrence. The reservoir temperature of the Xixiangchi Formation pool is about 40℃ lower than that of the Dengying Formation pool. Temperature plays a controlling role in both the sulfur isotopic fractionation and amounts of H2S generation during TSR.     

Immobilization of hemoglobin on platinum nanoparticles-modified glassy carbon electrode for H<Subscript>2</Subscript>O<Subscript>2</Subscript> sensing

This work described an amperometric hydrogen peroxide (H2O2) biosensor based on immobilization of hemoglobin (Hb) on a glassy carbon (GC) electrode modified by platinum nanoparticles, which was prepared by an in situ chemical reductive growth method. The electrochemical impedance measurements confirmed that the Hb was immobilized on the platinum nanoparticles-modified glassy carbon surface and has a synergistic effect with platinum nanoparti-cles in improving the catalytic reduction of H2O2. The Hb immobili...     

Temperature dependent kinetics of the gas-phase reaction of OH radicals with EMS

Using an improved smog chamber system,the temperature dependence of OH radical reaction with EMS was investigated over the temperature range of 297-346 K at 1.01×105 Pa pressure of air. The Arrhenius expression of the reaction was obtained for the first time. The mechanism of the reaction was also investigated.     

Intense laser induced field ionization of C<Subscript>2</Subscript>H<Subscript>2</Subscript>, C<Subscript>2</Subscript>H<Subscript>4</Subscript>, and C<Subscript>2</Subscript>H<Subscript>6</Subscript>

Using HOMO Field Ionization Model, the tunneling probabilities and the theoretical threshold intensities of the field ionizations of acetylene, ethylene, and ethane in intense laser field are calculated. C2H2, C2H4, and C2H6 were irradiated by 800 nm, 100 fs laser pulses with the intensity range of 10^13-10^14 W/cm^2. A TOF-mass spectrometer was coupled to the laser system and used to experimentally investigate the field ionization of these molecules. The experimental ionization threshold intensities are obtained. The calculating results of the three molecules agree well with the experimental results, indicating that HOMO Field Ionization Model is valid for the ionization of polyatomic molecules in intense laser field.     

Fabrication of porous alumina templates with a large-scale tunable interpore distance in a H<Subscript>2</Subscript>C<Subscript>2</Subscript>O<Subscript>4</Subscript>-C<Subscript>2</Subscript>H<Subscript>5</Subscript>OH-H<Subscript>2</Subscript>O solution

Highly ordered porous alumina templates with a large-scale tunable interpore distance （100-445 nm） have been successfully fabricated under an electric field of 40-180 V by modifying oxalic acid solution with adequate alcohol. The results under our experimental conditions show that the phenomena of burning and breakdown during the high-field anodization process can be avoided by adding a proper amount of alcohol to the oxalic acid solution. An excellent linear relationship between interpore distance and anodization voltage is obtained under 40-170 V, and the maximum anodization voltage that could be used to avoid burning and breakdown is 180 V.     

Synthesis, characterization and properties of ruthenium-substituted polyoxometallic acid H_6Ru(H_2O)FeW_(11)O_(39)·18H_2O with Keggin structure

The ruthenium-substituted polyoxometallic acid H6 [Ru(H2O)FeW 11O39 ]·18H2O was synthesized by stepwise acidification and stepwise addition of solutions of the component elements, and an ion-exchange-cooling method. The product was characterized using inductively coupled plasma spectrometry (ICP), Infrared Spectroscopy (IR), Ultraviolet Spectroscopy (UV), and X-ray diffraction (XRD). The results show that this complex has the Keggin structure. The determination of the thermal stability and proton conductivi...     

Synthesis, Characterization and Calorimetry of Ni（C4H8N2O3）2Cl2

A coordination complex was synthesized from NiCl2 and dipeptide glycylglycine（GG）. It was characterized by element analysis, NMR and TG methods, and then was determined to be Ni（C4HsN2O3）2Cl2. Using an isoperibolic reaction calorimeter, the standard molar enthalpy of formation of Ni（GG）2Cl2（solid） has been determined to be -（1 674.66±2.02） kJ · mol^-1 at 298.15 K.     

Effect of CH_3OOH on the atmospheric concentration of OH radicals

Peroxides play an i mportant role in atmosphericchemistry,because they are not only amongthe prin-ciple oxidants in the chemical conversion of O3andSO2,but also act as an atmospheric sink and tempo-rary reservoir for i mportant oxidizing radicals such asOH, HO2and RO2[1 ,2]. With the development ofmeasurement techniques , several organic peroxideswere identified in the atmosphere in addition to hy-drogen peroxide (H2O2)[3—5]. And among these or-ganic peroxides , methyl hydroperoxide ( MH…     

Improved hydrogen desorption properties of Co-doped Li<Subscript>2</Subscript>BNH<Subscript>6</Subscript>

The hydrogen desorption properties of Li 2 BNH 6 were improved by doping with cobalt. With the addition of CoCl 2 (7 wt%), more than 8 wt% of hydrogen was released from Li 2 BNH 6 at temperatures below 210°C, which is approximately 90°C lower than that of pristine Li 2 BNH 6 . X-ray diffraction, Fourier transform-infrared and Raman characterizations revealed that the dehydrogenation was a stepwise process with the formation of intermediates Li 4 BN 3 H 10 and LiBH 4 and final products of Li 3 BN 2 and LiH. The introduction of Co greatly accelerated the dehydrogenation of Li 4 BN 3 H 10 . X-ray absorption near-edge structure measurements revealed that Co and CoB species formed during ball milling of CoCl 2 with LiBH 4 and LiNH 2 , which may function as catalyst in the subsequent dehydrogenation.     

Effect of CH3OOH on the atmospheric concentration of OH radicals

Methyl hydroperoxide (CH₃OOH, MHP) is known to be a significant sink and reservoir of HO_x and RO_x radicals in the atmosphere. In order to investigate the impact of MHP on the concentration of atmospheric OH radicals, two key gas-phase reactions of MHP, i.e. the reactions with OH radicals and with UV photolysis, have been simulated at temperature of 293±2 K and total pressure of 1.01×10⁵ Pa, using the long path Fourier transform infrared (LP-FTIR) spectrometry. OH radicals are generated by the photolysis of O₃ in the presence of water vapor. Combined with the relative rate method, the reaction rate constant of MHP with OH radicals is determined to be (3.99±0.15)×10^-12 cm³?molecule^-1?s^-1, and thus the atmospheric lifetime of MHP is estimated at 2.9 days. Furthermore, from detailed analysis of the UV photolysis of MHP, the yield of OH radicals is obtained to be 0.91±0.04. Based on the MHP atmospheric lifetime and the yield of OH radicals, it is concluded that MHP plays an essential role in the redistribution of OH radicals in the troposphere.     

Effect of CH3OOH on the atmospheric concentration of OH radicals

Methyl hydroperoxide (CH₃OOH, MHP) is known to be a significant sink and reservoir of HO_x and RO_x radicals in the atmosphere. In order to investigate the impact of MHP on the concentration of atmospheric OH radicals, two key gas-phase reactions of MHP, i.e. the reactions with OH radicals and with UV photolysis, have been simulated at temperature of 293±2 K and total pressure of 1.01×10⁵ Pa, using the long path Fourier transform infrared (LP-FTIR) spectrometry. OH radicals are generated by the photolysis of O₃ in the presence of water vapor. Combined with the relative rate method, the reaction rate constant of MHP with OH radicals is determined to be (3.99±0.15)×10^-12 cm³?molecule^-1?s^-1, and thus the atmospheric lifetime of MHP is estimated at 2.9 days. Furthermore, from detailed analysis of the UV photolysis of MHP, the yield of OH radicals is obtained to be 0.91±0.04. Based on the MHP atmospheric lifetime and the yield of OH radicals, it is concluded that MHP plays an essential role in the redistribution of OH radicals in the troposphere.     

Measurement of rate constant for gas-phase reaction of DDVP with OH radical by using LP-FTIR

：Pollution caused by organic pesticides has received increasing attention. Until now, studies on organic pesticides pollution are mainly focused on soil and water. For reactions of organic pesticides in gas-phase, there are very little research results reported. Using a long path quartz reactor to simulate the atmospheric reaction of dimethyl_dichloro_vinyl_phosphate(DDVP) with OH radicals, the rate constant for the reaction at room temperature is measured at (3.06±0.46)×10-11 cm3 s-1 with Fourier transform infrared spectrograph.The result indicates that DDVP degrades relatively fast in the atmosphere and is unlikely to cause persistent pollution.     

Effect of CO<Subscript>2</Subscript> and H<Subscript>2</Subscript>O on gasification dissolution and deep reaction of coke

To more comprehensively analyze the effect of CO₂ and H₂O on the gasification dissolution reaction and deep reaction of coke, the reactions of coke with CO₂ and H₂O using high temperature gas-solid reaction apparatus over the range of 950-1250℃ were studied, and the thermodynamic and kinetic analyses were also performed. The results show that the average reaction rate of coke with H₂O is about 1.3-6.5 times that with CO₂ in the experimental temperature range. At the same temperature, the endothermic effect of coke with H₂O is less than that with CO₂. As the pressure increases, the gasification dissolution reaction of coke shifts to the high-temperature zone. The use of hydrogen-rich fuels is conducive to decreasing the energy consumed inside the blast furnace, and a corresponding high-pressure operation will help to suppress the gasification dissolution reaction of coke and reduce its deterioration. The interfacial chemical reaction is the main rate-limiting step over the experimental temperature range. The activation energies of the reaction of coke with CO₂ and H₂O are 169.23 kJ·mol-1 and 87.13 kJ·mol-1, respectively. Additionally, water vapor is more likely to diffuse into the coke interior at a lower temperature and thus aggravates the deterioration of coke in the middle upper part of blast furnace.     

Studies of several systems with air electrode electro-synthesizing H<Subscript>2</Subscript>O<Subscript>2</Subscript> on the spot for degrading aniline in aqueous

A gas diffusion electrode (air electrode) with a high current efficiency of electro-synthesizing H₂O₂ using O₂ in air was prepared. The several systems with air electrode as cathode of electro-synthesizing H₂O₂ on the reaction spot for degrading aniline in aqueous—electro-Fenton system, photo-excitation electro-H₂O₂ system and photo-electro-Fenton system, were developed. The rates of decomposition of H₂O₂ and mineralization of aniline were experimentally measured respectively under different conditions, and the results indicated there has an excellent parallel relation between decomposition rate of H₂O₂ and mineralization rate of aniline. Especially, photo-electro-Fenton system, where H₂O₂ is decomposed the fastest, is the best system of oxidizing and degrading organic toxicants. Compared photo-electro-Fenton system with photo-Fenton system, important role is revealed in the interface of air electrode. In this paper, the mineralization mechanism of aniline in the photo-electro-Fenton system was also discussed. Foundation item: Supported by the National Natural Science Foundation of China (200710026) and Foundation of Environmental Sciences Academy of Jiangsu Province. Biography: Cao xiao-yu (1979-), male, Master candidate, research direction: Electrochemistry     

Quantitative relationship between production and removal of OH and HO<Subscript>2</Subscript> radicals in urban atmosphere

Atmospheric oxidizing capacity is the essential feature of urban and regional air. And OH and HO2 radicals are the key species indicating atmospheric oxidizing capacity. Using Guangzhou City as a case, this work has conducted field measurements of photochemistry relevant pollutants including O3, NOx, VOCs, H2O2, HNO2 and CO,SO2. The concentrations of OH radical are measured simultaneously by impregnated filter trapping and HPLC (IFTHPLC) method. The factors influencing OH levels are assessed. Based on understanding of OH and HO2 air chemistry, the production and removal rates of these 2 radicals are calculated. The results show that the budget of OH and HO2 can generally be closed, the radical transformation between OH and HO2 dominates the sources and sinks of them, and also the photolysis of HNO2 and HCHO is the significant source of OH and HO2 respectively.     

NO and H2O2 induced by Verticillium dahliae toxins and its influence on the expression of GST gene in cotton suspension cells

Nitric oxide （NO） and hydrogen peroxide （H2O2） have been shown to be important signaling molecules that participate in the regulation of several physiological processes. In particular, they have significant role in plant resistance to pathogens by contributing to induction defense genes. Here, whether NO and H2O2 participate in the resistance responses against Verticillium dahliae toxins （VD-toxins） and their effects on the expression of GSTgene are studied. The results reveal that NO and H2O2 are produced as part of a complex network of signals that respond to VD-toxins and may converge to function both synergistically and independently by inducing resistant responses. GSTgene is potentially involved in the resistance mechanism in the cotton suspension cells. NO induces the expression of GSTgene independently of H2O2. H2O2 may be a more potent signal in the resistance responses against VD-toxins.     

Theoretical study on the lithium bond interaction of furan homologues C4H4Y （Y=O,S） with LiCH3 via DFT and MP2

The optimizations geometries and interaction energy corrected by BSSE of the complexes between C4H4Y （Y=O, S） and CHiLi have been calculated at the B3LYP/6-311＋＋G^＊＊ and MP2/6-311＋＋G^＊＊ levels. Three complexes were obtained. Abnormally, the calculations showed that all the C10--Li14 bond lengths increased obviously but the blue-shift of C10-Li14 stretching frequency occurred after formed complexes. The calculated binding energy with basis set super-position error （BSSE） and zero-point vibrational energy corrections of complexes I-III is -45.757, -35.700 and -39.107 kJ·mol^-1, respectively. The analyses on the combining interaction with the atom-in-molecules theory （AIM） also showed that a relatively strong lithium bond interaction presented in furan homologues C4H4Y-LiCH3 systems. Natural bond orbital theory （NBO） analysis has been performed, and the results revealed that the complex I is formed with n-σ type lithium bond interaction between C4H40 and LiCH3, complex II is formed with TT-s type lithium bond interaction between C4H4O and LiCH3, and complex III is formed with TT-s and n-s type lithium bond interactions between C4H4S and LiCH3, respectively.     

Kinetic parameters of oscillating reaction of amino acid- BrO3^——Mn^2＋-H2SO4-acetone system

In the previous papers[1—3], the oscillating reactionusing amino acids as organic substrates was studied. Inorder to obtain information about the kinetic parameters ofoscillating reaction of amino acids in amino acid- BrO3 - ?Mn2 -H2SO4-acetone sy…     

Comparative analysis of the dissolution kinetics of galena in binary solutions of HCl/FeCl<Subscript>3</Subscript> and HCl/H<Subscript>2</Subscript>O<Subscript>2</Subscript>

A comparative study of the dissolution kinetics of galena ore in binary solutions of FeCl₃/HCl and H₂O₂/HCl has been undertaken. The dissolution kinetics of the galena was found to depend on leachant concentration, reaction temperature, stirring speed, solid-to-liquid ratio, and particle diameter. The dissolution rate of galena ore increases with the increase of leachant concentration, reaction temperature, and stirring speed, while it decreases with the increase of solid-to-liquid ratio and particle diameter. The activation energy (E _a) of 26.5 kJ/mol was obtained for galena ore dissolution in 0.3 M FeCl₃/8.06 M HCl, and it suggests the surface diffusion model for the leaching reaction, while the E _a value of 40.6 kJ/mol was obtained for its dissolution in 8.06 M H₂O₂/8.06 M HCl, which suggests the surface chemical reaction model for the leaching reaction. Furthermore, the linear relationship between rate constants and the reciprocal of particle radius supports the fact that dissolution is controlled by the surface reaction in the two cases. Finally, the rate of reaction based on the reaction-controlled process has been described by a semiempirical mathematical model. The Arrhenius and reaction constants of 11.023 s⁻¹, 1.25×10⁴ and 3.65×10² s⁻¹, 8.02×10⁶ were calculated for the 0.3 M FeCl₃/8.06 M HCl and 8.06 M H₂O₂/8.06 M HCl binary solutions, respectively.