FeII(EDTA)络合吸收NO体系中吸收液的生物再生

利用驯化的微生物对FeII(EDTA)NO的再生进行了研究.结果表明,驯化过程中,分子量相对较低的乙醇比葡萄糖更适合于作为该体系的碳源200mg·L-1的乙醇添加量可以使9.92 mmo1·L-1FeII(EDTA)NO完全再生,添加过量碳源对反应速率没有促进作用.当FeII(EDTA)NO浓度为7.3 mmol·L-1,菌体接种量大于80mg(菌体干重)·L"时就能满足再生需要.生物再生的适宜pH值和温度范围分别为6 5～7.5和30～42.5℃;实验考察条件下,该反应符合一级降解动力学,最大反应速率ymax为5.4mmo1·L-1·h-1,半饱和速率常数km为63.8mmo1·L-1.     

Endothelial Nitric Oxide Synthase (eNOS) 4b/a Gene Polymorphisms and Coronary Artery Disease: Evidence from a Meta-Analysis

A variety of studies have suggested that the 4b/a polymorphism in the endothelial nitric oxide synthase (eNOS) was associated with coronary artery disease (CAD) risk. However, the data remain conflicting. The aim of the present meta-analysis was to estimate the overall association between risk of CAD and eNOS 4b/a polymorphism. Case-control, cohort or cross-sectional studies evaluating the association between eNOS 4b/a polymorphism and CAD susceptibility were systematically identified in PubMed up to 31 October 2013. Pooled odds ratios (OR) and corresponding 95% confidence intervals (CIs) were calculated to assess the association in overall and subgroup analyses. A total of 10,617 cases and 8302 controls from 37 studies were included in the study. The results of overall analysis revealed significant positive associations between CAD risk and eNOS 4b/a polymorphism in homozygote comparisons (OR = 1.47, 95% CI = 1.16–1.87), heterozygote comparisons (OR = 1.14, 95% CI = 1.02–1.27) and dominant models (OR = 1.18, 95% CI = 1.06–1.33). In subgroup analyses, similar associations were identified in African individuals, as determined using population-based source subgroups and noted in small-and-moderate sample size subgroups (case sample size or control sample size <500). The current meta-analysis revealed that eNOS 4b/a polymorphisms could be a risk factor for developing CAD, particularly in African populations and population-based subgroups.     

脉冲电晕结合Ca(OH)2吸收法脱硫脱硝

Removal of SO2 and NOx by pulsed corona combined with in situ alkali absorption was experimentally investigated.In the reactor,a plate-wire-plate combination is devised for generating pulsed corona and then alkaline absorbent slurries were introduced into the reactor by a continuous band conveying system to capture the gaseous reaction products.It was found that both SO2 and NO could be removed by corona combined with in situ alkali absorption.The removal of SO2 increased to 75%with the corona discharge,compared with 60%removal only with Ca(OH)2 absorption.About 40%removal of NO was reached by pulsed corona combined with in situ Ca(OH)2 absorption.It was found that SO2 and NO in the gas stream are oxidized to SO3 and NO2 by pulsed corona respectively,and then absorbed by the alkali in the reactor.The removals of SO2 as well as NO were higher with Ca(OH)2 as the absorbent,compared with using CaCO3 or ZnO.     

Cure kinetics of a cyanate ester blended with poly(phenylene oxide)

The cure kinetics and mechanisms of a cyanate ester and its blends with poly(phenylene oxide) (PPO) were studied using differential scanning calorimetry and Fourier transform infrared spectroscopy. The results showed that blending with PPO has an effect on the cure reaction. Reaction rates of the cyanate ester blends were higher in the initial stage than that of the neat cyanate ester; however, the conversion reached decreased with increasing PPO content. Experimental data, showing autocatalytic behavior, were compared with Kamal's model which includes two apparent rate constants and two reaction orders. This model apparently describes well the kinetics, but diffusion control in the vitrified state limits the reactions from going further. By introducing a diffusion factor f(α) into this model, it becomes possible to predict the cure kinetics over the whole range of conversion. Copyright © 2006 Society of Chemical Industry     

Removal of TEX vapours from air in a peat biofilter: influence of inlet concentration and inlet load

This paper presents the results of the study of the removal of toluene, ethylbenzene, and o‐xylene (TEX) by biofiltration using a commercial peat as filter‐bed material. Runs with a single organic compound in air, and with the mixture of TEX in air, were carried out for at least 55 days in laboratory‐scale reactors inoculated with a conditioned culture. The influence of organic compound inlet load and of gas flow rate on the biofilter's performance was studied, including relatively high values of pollutant inlet concentration (up to 4.3 gC m^?3 for ethylbenzene, 3.2 gC m^?3 for toluene, and 2.7 gC m^?3 for o‐xylene). Results obtained show maximum elimination capacities of 65 gC m^?3 h^?1 for o‐xylene, 90 gC m^?3 h^?1 for toluene, and 100 gC m^?3 h^?1 for ethylbenzene, and high removal efficiency (>90%) even for moderately elevated concentrations: 3.0, 2.5 and 1.8 gC m^?3 for ethylbenzene, toluene and o‐xylene, respectively. The behaviour of the TEX mixture was in good agreement with the results obtained for the runs in which only one organic compound was present. Ethylbenzene and toluene are degraded easier than o‐xylene, and inhibitory effects due to the presence of multiple substrates were not observed. Copyright © 2005 Society of Chemical Industry     

Pd/Al2O3催化剂上CH4选择性还原NO的研究

考察了Pd/Al₂O₃、In/Al₂O₃和Co/Al₂O₃对甲烷选择性还原NO的催化活性。结果表明，采用浸渍法制备的Pd/Al₂O₃、In/Al₂O₃和Co/Al₂O₃三种催化剂，在有氧气氛下，用CH₄作还原剂催化还原NO时，Pd/Al₂O₃催化剂的活性最佳，热稳定性好，在550 ℃，用CH₄选择还原NO，Pd/Al₂O₃催化剂表现出较强的催化能力，NO的转化率达到100%。在高空速实验中，该催化剂亦表现出较高的活性，其活性顺序为Pd/Al₂O₃>In/Al₂O₃>Co/Al₂O₃。实验研究了助催化剂、氧含量以及空速对Pd/Al₂O₃催化剂活性的影响。     

Interaction of poly(ethylene oxide) with solvents: 1. Preparation and swelling of a crosslinked poly(ethylene oxide) hydrogel

Crosslinked polymer gels containing over 90 wt% poly(ethylene oxide) have been made and their swelling in a large number of solvents studied. The results confirm previous observations that the interaction of poly(ethylene oxide) with water is quite different from the interaction with most other solvents. Formamide also appears to be anomalous. The crosslinked polymer, swollen with water, shows dramatic syneresis between 0° and 100°C but at 100°C still retains approximately three molecules of water for each ether oxygen.     

Electrodeposition of insulating poly(phenylene oxide) films with variable thickness

Ability to control key characteristics of electrodeposited polymers plays a vital role for their applications. In this work the results on tailoring the thickness of electronically insulating poly(phenylene oxide) (PPO) type polymer films have been showed. Pinhole‐free PPO films with variable thickness in the range of 10–50 nm were grown by controlling the potential applied during the electrochemical polymerization on the surface of titanium nitride (TiN) substrates. The insulating properties of the PPO film were confirmed by testing its permeability to redox species by cyclic voltammetry. Thermal stability of the PPO films with different thicknesses was investigated by in‐situ spectroscopic ellipsometry up to 400 °C in various environments. This insight is important for the optimization of the PPO anneal conditions in order to remove the residual solvent and potentially improve the polymer chains stacking. Our results provide the basis for electrodeposition of PPO films with variable thickness for diverse applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44533.     

Molecular Mechanisms of Nitric Oxide (NO) Signaling and Reactive Oxygen Species (ROS) Homeostasis during Abiotic Stresses in Plants

Abiotic stressors, such as drought, heavy metals, and high salinity, are causing huge crop losses worldwide. These abiotic stressors are expected to become more extreme, less predictable, and more widespread in the near future. With the rapidly growing human population and changing global climate conditions, it is critical to prevent global crop losses to meet the increasing demand for food and other crop products. The reactive gaseous signaling molecule nitric oxide (NO) is involved in numerous plant developmental processes as well as plant responses to various abiotic stresses through its interactions with various molecules. Together, these interactions lead to the homeostasis of reactive oxygen species (ROS), proline and glutathione biosynthesis, post-translational modifications such as S-nitrosylation, and modulation of gene and protein expression. Exogenous application of various NO donors positively mitigates the negative effects of various abiotic stressors. In view of the multidimensional role of this signaling molecule, research over the past decade has investigated its potential in alleviating the deleterious effects of various abiotic stressors, particularly in ROS homeostasis. In this review, we highlight the recent molecular and physiological advances that provide insights into the functional role of NO in mediating various abiotic stress responses in plants.     

Separation of Water and Nitric Acid with Porous Hydrophobic Membrane by Air Gap Membrane Distillation (AGMD)

Abstract

This study investigates the effect of operation parameters on the separation of nitric acid‐water mixture using air gap membrane distillation (AGMD). Porous hydrophobic PTFE membrane was used. The performance was evaluated based on the permeate flux and the nitric acid selectivity. Operating parameters such as feed solution temperature, feed concentration, flow rate, and air gap width were varied. Nitric acid selectivity was found to increase with the increase in feed solution temperature, feed concentration, flow rate, and air gap width. Permeate flux increased, when the feed temperature and the flow rate were increased. The effect of recirculation of the feed solution was also studied. With the recirculation mode, at different initial solution volumes, it was observed that the nitric acid concentration in the feed and the permeate, increased. The rate of flux decline was greater, when the initial feed solution volume was lower.     

Extraction of Lanthanides(III), U(VI), and Th(IV) from Nitric Acid Solutions with 1,5-N,N'-Bis[(diphenylphosphoryl)acetylamino]pentanes

Novel polyfunctional neutral organophosphorus ligands, namely 1,5-N,N'-bis[(diphenylphosphoryl)acetyl(alkyl)amino]pentanes [Ph₂P(O)CH₂C(O)NR]₂(CH₂)₅ (Ia, R = C₆H₁₃; Ib, R = CH₃), were studied as extractants for Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, and U from nitric acid solutions. The effect of both HNO₃ concentration in the aqueous phase and that of the extractant in the organic phase on the extraction of metal ions is considered. The stoichiometry of the extracted complexes was determined by the slope analysis method. Compared with the related bisaminopentane [Ph2P(O)CH₂C(O)NH]₂(CH₂)₅ (Ic), the replacement of hydrogen atoms at the amide nitrogens by alkyl radicals (compounds Ia,b) leads to an increase of metal ions extraction. Bis-CMPO ligands Ia-c were found to possess higher extraction efficiency towards U(VI), Th(IV), and Ln(III) than their monophosphorylated analogue Ph₂P(O)CH₂C(O)N(C₄H₉)₂.     

Change in the molecular weight distribution of poly(ethylene oxide) caused by the complexation with poly(acrylic acid)

The complexation between poly(ethylene oxide) (PEO) and poly(acrylic acid) (PAA) was made by using double the molar quantity of either polymer component at pH 2 where the resulting complex completely precipitates. After the removal of the precipitate, PEO or PAA remaining in the supernatant was subjected to gel permeation chromatography to investigate the change in the molecular weight distribution (MWD) caused by the complexation. No remarkable difference is observed in the MWD curves for PEO[1] (M_w=1.37 × 10⁴) before and after the complexation with PAA[1] (M_w=1.10 × 10³) and PAA[2] (M_w=4.16 × 10⁵). However, the MWD curves of PEO[2] (M_w=1.26 × 10⁵) and PAA[2] become shortened and shift to the low molecular weight side after the complexation with PAA[1] or [2] and PEO[2], respectively. This tendency is enhanced by increasing the complexation temperature. From these results, it is indicated that the complexation between PEO and PAA deals with an equilibrium reaction, and the equilibrium constant is dependent on the chain length of both polymer components and also on the complexation temperature.     

Actinide(III)/Lanthanide(III) Separation Via Selective Aqueous Complexation of Actinides(III) using a Hydrophilic 2,6-Bis(1,2,4-Triazin-3-Yl)-Pyridine in Nitric Acid

i-SANEX is a process for separating actinides(III) from used nuclear fuels by solvent extraction: Actinides(III) and lanthanides(III) are co-extracted from a PUREX raffinate followed by selective back extraction of actinides(III) from the loaded organic phase. This step requires a complexing agent selective for actinides(III). A hydrophilic sulfonated bis triazinyl pyridine (SO₃-Ph-BTP) was synthesized and tested for selective complexation of actinides(III) in nitric acid solution. When co-extracting Am(III) and Eu(III) from nitric acid into TODGA, adding SO₃-Ph-BTP to the aqueous phase suppresses Am(III) extraction while Eu(III) is extracted. Separation factors in the range of 1000 are achieved. SO₃-Ph-BTP remains active in nitric acid up to 2 mol/L. As a result of this performance, buffering or salting-out agents are not needed in the aqueous phase; nitric acid is used to keep the lanthanides(III) in the TODGA solvent. These properties make SO₃-Ph-BTP a suitable candidate for i-SANEX process development.     

Synthesis and characterization of poly(dihalophenylene oxide)s by solid-state thermal-decomposition of manganese phenolate complexes with tetramethylethylenediamine

The characterization of poly(dihalophenylene oxide)s synthesized by solid-state thermal decomposition of manganese phenolate complexes with tetramethylethylenediamine (TMEN) ligand is reported. The complexes prepared with 2,4,6-trichlorophenol (TCP) and 2,4,6-tribromophenol (TBP) have been characterized by FTIR spectroscopy, elemental analysis, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The dependence of the polymerization yield on temperature and decomposition time of the complexes has been investigated. Maximum polymerization yield is obtained at 220°C and 48 h. The polymers synthesized from the complexes have been characterized by ¹H-NMR and FTIR spectroscopy, DSC, and viscometric measurements. All polymers have a branched structure, a high T_g and low intrinsic viscosity. © 1999 Society of Chemical Industry     

Fractional Crystallization Kinetics of Poly(ethylene oxide) in Its Blends with Poly(butylene succinate): Molecular Weight Effects

The fractional crystallization kinetics and phase behavior of PEO with different molecular weights (MWs) in its miscible crystalline/crystalline blends with PBS are studied. Both fractional crystallization kinetics and phase segregation of PEO in PBS/PEO blends are dramatically influenced by its MW. PEO with a medium MW (20 kDa) shows a significant fractional crystallization in the blends with PBS crystallized at a high T_IC,PBS, which, however, is dramatically depressed in the blends with a very low or high MW of PEO. This indicates that the PEO component with a medium MW is more ready to segregate into the interlamellar region of PBS crystals than those with a very low or high MW. The MW‐dependent fractional crystallization kinetics and phase segregation of PEO component in the PBS/PEO blends are discussed.

     

Crystallization Kinetics and Hydrophilicity Improvement of Biodegradable Poly(butylene succinate) in its Miscible Blends with Poly(ethylene oxide)

The spherulitic morphology and growth, overall isothermal crystallization kinetics and hydrophilicity of PBSU were investigated by POM, DSC and WCA measurements in its miscible blends with PEO. The Hoffman‐Lauritzen equation was employed to analyze the spherulitic growth rates of neat and blended PBSU, which show a crystallization regime transition between regime II and III. The overall crystallization rates of PBSU decreased with increasing crystallization temperature, regardless of blend composition, while the crystallization mechanism does not change. A significant improvement in the hydrophilicity of PBSU can be achieved by blending with different weight fractions of PEO, which may be essential for the practical application of PBSU/PEO blends.