惠民凹陷临北地区基山砂体油气成藏主控因素研究

临北地区位于惠民凹陷中央隆起带中部,针对该区沙三中亚段基山砂体的储层类型、圈闭规模及储层有效性不清等问题,从烃源条件、储层物性、沉积相展布以及构造特征等方面入手,通过钻井和试油成果资料,综合应用地质、地化分析和地球物理研究手段,剖析了油气成藏条件及主控因素.结果表明,紧邻的临南洼陷沙三段优质烃源岩是临北基山砂体的主要来...     

Hydrogen production for energy: An overview

Power to hydrogen is a promising solution for storing variable Renewable Energy (RE) to achieve a 100% renewable and sustainable hydrogen economy. The hydrogen-based energy system (energy to hydrogen to energy) comprises four main stages; production, storage, safety and utilisation. The hydrogen-based energy system is presented as four corners (stages) of a square shaped integrated whole to demonstrate the interconnection and interdependency of these main stages. The hydrogen production pathway and specific technology selection are dependent on the type of energy and feedstock available as well as the end-use purity required. Hence, purification technologies are included in the production pathways for system integration, energy storage, utilisation or RE export. Hydrogen production pathways and associated technologies are reviewed in this paper for their interconnection and interdependence on the other corners of the hydrogen square.Despite hydrogen being zero-carbon-emission energy at the end-use point, it depends on the cleanness of the production pathway and the energy used to produce it. Thus, the guarantee of hydrogen origin is essential to consider hydrogen as clean energy. An innovative model is introduced as a hydrogen cleanness index coding for further investigation and development.     

英国景观协会注册景观师认证体系

本文基于英国景观学会会员资格认证体系,介绍了目前获得英国注册景观师资格的“专业执业考试”体系。并对将要实行的注册景观师“资格进阶体系”做出了简要介绍。     

Kinetic and mechanistic examinations of reductive transformation pathways of brominated methanes with nano-scale Fe and Ni/Fe particles

In this study, carbon tetrabromide (CTB), bromoform (BF) and dibromomethane (DBM) were the target compounds investigated for their reduction kinetics and pathways with nano-scale Fe and Ni/Fe particles synthesized in laboratory. The BET surface areas of these nano-scale particles were around two orders of magnitude higher than that of the commercial micro-scale Fe particles. Batch reduction experiments were carried out with a metal loading of 2.5gl(-1) for the nano-scale particles, and 125gl(-1) for the commercial micro-scale Fe. The nano-scale Ni/Fe was the most reactive for reductive dehalogenation of the brominated methanes. The rates of bromide ion liberated during the reduction of the brominated methanes were usually higher than the disappearance rates of the parent compounds, indicating occurrence of concerted debromination mechanism. Analysis of the reduction kinetics showed that CTB and BF were mainly reduced through hydrogenolysis reaction, while over 76% of DBM was reduced through concerted reductive debromination to methane. Addition of Ni to Fe increased the specific reduction rates of the target compounds and reactive intermediates, but only marginally changed the distribution of their end products. Through comprehensive kinetic and mechanistic examinations of the reduction dehalogenation of various brominated methanes, a scheme summarizing their overall reduction pathways with the nano-scale Fe and Ni/Fe is proposed.     

Thermal decomposition of trichloroethylene under a reducing atmosphere of hydrogen

The thermal reaction of trichloroethylene (TCE: C₂HCl₃) has been conducted in an isothermal tubular flow reactor at 1 atm total pressure in order to investigate characteristics of chlorinated hydrocarbons decomposition and pyrolytic reaction pathways for formation of product under excess hydrogen reaction environment. The reactions were studied over the temperature range 650 to 900 °C with reaction times of 0.3–2.0 s. A constant feed molar ratio C₂HCl₃: H₂ of 4: 96 was maintained through the whole experiments. Complete decay (99%) of the parent reagent, C₂HCl₃ was observed at temperature near 800 °C with 1 s reaction time. The maximum concentration (28%) of C₂H₂Cl₂ as the primary intermediate product was found at temperature 700 °C where up to 68% decay of C₂HCl₃ occurred. The C₂H₃Cl as highest concentration (19%) of secondary products was detected at 750 °C. The one less chlorinated methane than parent increased with temperature rise subsequently. The number of qualitative and qualitative chlorinated products decreased with increasing temperature. HCl and dechlorinated hydrocarbons such as C₂H₄, C₂H₆, CH₄ and C₂H₂ were the final products at above 800 °C. The almost 95% carbon material balance was given over a wide range of temperatures, and trace amounts of C₆H₆, C₄H₆ and C₂HCl were observed above 800 °C. The decay of reactant, C₂HCl₃ and the hydrodechlorination of intermediate products, resulted from H atom cyclic chain reaction via abstraction and addition replacement reactions. The important pyrolytic reaction pathways to describe the important features of reagent decay, intermediate product distributions and carbon mass balances, based upon thermochemical and kinetic principles, were suggested. The main reaction pathways for formation of major products along with preliminary activation energies and rate constants were given.     

Extended detailed balance for systems with irreversible reactions

The principle of detailed balance states that in equilibrium each elementary process is equilibrated by its reverse process. For many real physico-chemical complex systems (e.g. homogeneous combustion, heterogeneous catalytic oxidation, most enzyme reactions, etc.), detailed mechanisms include both reversible and irreversible reactions. In this case, the principle of detailed balance cannot be applied directly. We represent irreversible reactions as limits of reversible steps and obtain the principle of detailed balance for complex mechanisms with some irreversible elementary processes. We prove two consequences of the detailed balance for these mechanisms: the structural condition and the algebraic condition that form together the extended form of detailed balance. The algebraic condition is the principle of detailed balance for the reversible part. The structural condition is the convex hull of the stoichiometric vectors of the irreversible reactions has empty intersection with the linear span of the stoichiometric vectors of the reversible reactions. Physically, this means that the irreversible reactions cannot be included in oriented cyclic pathways.The systems with the extended form of detailed balance are also the limits of the reversible systems with detailed balance when some of the equilibrium concentrations (or activities) tend to zero. Surprisingly, the structure of the limit reaction mechanism crucially depends on the relative speeds of this tendency to zero.     

Diversity in Genetic Regulation of Bacterial Fimbriae Assembled by the Chaperone Usher Pathway

Bacteria express different types of hair-like proteinaceous appendages on their cell surface known as pili or fimbriae. These filamentous structures are primarily involved in the adherence of bacteria to both abiotic and biotic surfaces for biofilm formation and/or virulence of non-pathogenic and pathogenic bacteria. In pathogenic bacteria, especially Gram-negative bacteria, fimbriae play a key role in bacteria–host interactions which are critical for bacterial invasion and infection. Fimbriae assembled by the Chaperone Usher pathway (CUP) are widespread within the Enterobacteriaceae, and their expression is tightly regulated by specific environmental stimuli. Genes essential for expression of CUP fimbriae are organised in small blocks/clusters, which are often located in proximity to other virulence genes on a pathogenicity island. Since these surface appendages play a crucial role in bacterial virulence, they have potential to be harnessed in vaccine development. This review covers the regulation of expression of CUP-assembled fimbriae in Gram-negative bacteria and uses selected examples to demonstrate both dedicated and global regulatory mechanisms.     

Degradation of an Anthraquinone Dye by Ozone/Fenton: Response Surface Approach and Degradation Pathway

A coupled O₃/Fenton process is applied to study the degradation ef?ciency of organic pollutants. The C.I. Acid Blue 80 (AB80), a kind of anthraquinone dye, is used as target contaminant. The results show that the combination of ozonation and Fenton process is a highly effective way of removing color from wastewater. Response surface methodology is applied to optimize the working conditions and the effects and interactions among initial pH (X₁), mole ratio of H₂O₂/Fe²⁺ (X₂) and ozone flux (X₃) are investigated. Regression equations determines that the best condition is that initial pH = 2.85, [H₂O₂]/[Fe²⁺] = 18.10 and ozone flux = 55.70 L.h^?1. It turns out the relative error of 1.32% with the predicted model when the actual value which is 88.76% in the best condition, compared to the predictive value of 88.95% under same condition. UV-Vis and FT-IR analysis are used as an assisted technique to study degradation mechanism during the oxidation process. The intermediate products are determined by gas chromatography/mass spectrometry (GC/MS) analysis and the plausible degradation pathway is proposed.     

农用杀菌剂吩嗪-1-羧酸的生物合成与基因调控

吩嗪-1-羧酸是一种安全、广谱的微生物源农药，可以抑制多种植物病原真菌，有效防治作物病害。本文对假单胞菌中吩嗪-1-羧酸的生物合成途径及吩嗪-1-羧酸衍生物的形成等进行了阐述，分析了吩嗪-1-羧酸合成的基因调控方式以及环境因素变化对其合成的影响。吩嗪-1-羧酸已广泛应用于生物防治．具有良好的应用前景。