吸附转移溶出伏安法测定氟罗沙星注射液含量

A new,simple and convenient method was proposed to determine FLRX.Cyclic voltammetric behavior of Fleroxacin(FLRX) on graphite electrode was studied.FLRX can be strongly adsorbed on graphite electrode.At the potential of +1.040V(vs.SCE),FLRX is oxidized and adsorbed on the electrode surface.Using HAc～NaAc as a buffer solution, FLRX showed a reduction wave and the peak potential of -0.110V(vs.SCE) by linear sweep voltammetry after the electrode was washed by double distilled water.A new method for the determination of FLRX was established by adsorptive transfer stripping voltammetry.The peak current is proportional to the concentration of fleroxacin in the range of 4～42 μ g/mL.The method is simple,sensitive,fairly free of interference and accurate.

地下水系统中石油污染物的吸附转移研究

本文以吸附理论为基础，探讨地下水系统的多组分吸附，并通过实验建立溶解油在固相和液相之间的分配关系──吸附等温式；然后，根据实测的吸附等温线和突破曲线确定溶解油在地下水系统中的阻滞系数，从而把反应性石油污染物的对流弥散迁移和相间转移有机地结合起来。

新型吸附相转移催化剂对有机废水的净化性能

以糠醛渣为基体,通过改性、炭化、掺杂纳米钛酸钙,制备复合吸附相转移催化剂;以热处理废水COD去除为目标,以臭氧为氧化剂,采用预吸附相转移再通臭氧催化氧化工艺,研究该材料对高浓度难降解有机废水的净化性能,考察吸附催化条件对废水COD去除率的影响。结果表明:合成的糠醛渣基复合吸附催化剂净化热处理含油废水时,首先将废水中的有机物吸附于其上,实现难降解有机物的液-固相转移,再与臭氧反应,吸附相转移大大提高了臭氧催化氧化能力;吸附40min,再通20mg/L臭氧催化氧化120min,废水COD去除率达到79%以上;吸附催化材料重复使用6次,COD去除率下降在5%以内,该材料具有较好的稳定性。

基质金属蛋白酶含量及表达与膀胱癌侵袭转移的关系

目的 :探讨基质金属蛋白酶 2 (MMP- 2 )、基质金属蛋白酶 9(MMP- 9)的血清含量及组织表达与膀胱移行细胞癌侵袭转移的关系。方法 :用 EL ISA法检测 6 8例膀胱移行细胞癌患者及 2 0例正常对照组血清中MMP- 2和 MMP- 9的含量 ;应用免疫组织化学 SP法 ,检测 6 8例膀胱移行细胞癌、 10例正常膀胱黏膜组织中MMP- 2和 MMP- 9的表达及分布情况。结果 :膀胱癌患者血清中 MMP- 2和 MMP- 9含量明显高于正常对照组(P<0 .0 1) ,淋巴结转移组患者血清 MMP- 2及 MMP- 9含量高于无淋巴结转移组 ;膀胱癌组织中 MMP- 2及MMP- 9表达显著高于癌旁组织及正常黏膜 ,随着肿瘤分级的增高 MMP- 2和 MMP- 9表达显著增强 (P<0 .0 5 )。结论 :MMP- 2和 MMP- 9血清含量及组织表达与膀胱癌侵袭转移有密切关联 ,可以作为判断膀胱移行细胞癌预后的客观指标。

浮萍科植物水环境修复及其资源化利用综述

生物生态修复技术以其处理效果好、投资少、耗能低、操作简单、不形成二次污染和生态景观效果好等优点,在水环境修复中被广泛应用。植物修复是生物生态修复技术的一种,选取适宜的水生植物是其关键。浮萍科(Lemnaceae)植物具有生长速度快、富含生物质蛋白和淀粉、适应环境能力强、易管理的特点,且具有较高的氮磷、有机物和重金属等吸附转移的能力,因此常被作为污水生物生态修复处理和环境毒理学试验的优势水生植物和农业生产以及能源行业的重要原材料。系统论述浮萍科植物的生物学特征,介绍其在环境修复、环境毒理学以及能源、农业生产等领域的开发利用,提出目前浮萍科植物在水环境修复领域及资源化利用方面存在的主要问题,并对未来的研究方向进行展望。

Insights into SO_2 and H_2O co-adsorption on Cu(100) surface with calculations of density functional theory

The co-adsorption behaviors of SO2 and H2 O on face-centered cubic Cu（100） ideal surface were studied using the GGA-r PBE method of density functional theory（DFT） with slab models. The optimized structures of single H2 O and SO2 on Cu（100） surface were calculated at the coverage of 0.25 ML（molecular layer） and 0.5 ML. The results show that there was no obvious chemical adsorption of them on Cu（100） surface. The adsorbed structures, adsorption energy and electronic properties including difference charge density, valence charge density, Bader charge analysis and partial density of states（PDOS） of co-adsorbed structures of H2 O and SO2 were investigated to illustrate the interaction between adsorbates and surface. H2 O and SO2 can adsorb on surface of Cu atoms chemically via molecule form at the coverage of 0.25 ML, while H2 O dissociated into OH adsorbed on surface and H bonded with SO2 which keeps away from surface at the coverage of 0.5 ML.

Eco-friendly corrosion inhibitor from Pennisetum purpureum biomass and synergistic intensifiers for mild steel

Extracts of elephant grass （Penniseturn purpureum） blended with some intensifier halides like ammonium chloride （AMC） and potassium iodide （PTI） were investigated as corrosion inhibitor for mild steel. The corrosion process was monitored in 3.5% HCI by mass loss and electrochemical techniques at 30, 40, 50, 60 and 90 ℃. Addition of AMC and PTI increased the inhibition efficiency with the highest inhibition efficiency obtained with PTI blend- ed extract. The blends behaved as mixed type inhibitors and were spontaneously adsorbed on mild steel surface in exothermic nature. Synergistic parameters of the intensifier ions revealed cooperative effect. Kinetic data treatment indicated increase in energy barrier by intensifier ions. The results demonstrate that elephant grass extract blended with halide ions can act as alternative ecofriendly inhibitor for mild steel at elevated temperatures.

Adsorption and Transfer Properties for Toluene and pDichlorobenzene in Dense CO_2/Silica Gel Packed Bed System by Moment Method and Time-Domain Analysis

Based on chromatographic theory, the moment method and the time-domain fitting analysis were applied to measure and evaluate the adsorption equilibrium constant and mass transfer properties (axial dispersion coefficient and effective intra-particle diffusivity) for toluene and p-dichlorobenzene on silica gel adsorbent in the subcritical and supercritical CO2. An apparatus based on supercritical fluid chromatography was established and the experiments were performed at temperatures of 298.15-318.15 K and pressures of 7.5-17.8 MPa. The two methods have been compared. The results show that for the systems studied here the moment method can give reasonable values for both adsorption equilibrium constant and mass transfer properties, but the time-domain analysis only can obtain the adsorption equilibrium constant. The dependence of adsorption equilibrium constant and mass transfer properties on temperature and pressure was investigated.

Thermo‐driven photocatalytic CO reduction and H_(2) oxidation over ZnO via regulation of reactant gas adsorption electron transfer behavior

Photothermal catalysis is a widely researched field in which the reaction mechanism is usually investigated based on the photochemical behavior of the catalytic material.Considering that the adsorption of reactants is essential for catalytic reactions to occur,in this study,the synergistic effect of photothermal catalysis is innovatively elucidated in terms of the electron transfer behavior of reactant adsorption.For the H_(2)+O2 or CO+H_(2)reaction systems over a ZnO catalyst,UV irradiation at 25°C or heat without UV irradiation did not cause H_(2)oxidation or CO reduction;only photothermal conditions(100 or 150°C+UV light)initiated the two reactions.This result is related to the electron transfer behavior associated with the adsorption of CO or H_(2)on ZnO,in which H_(2)or CO that lost an electron could be oxidized by O2 or hydroxyls.However,the electron‐accepting CO could be reduced by the electron‐donating H_(2)into CH4 under photothermal conditions.Based on the in‐situ characterization and theoretical calculation results,it was established that the synergistic effect of the photothermal conditions acted on the(002)crystal surface of ZnO to stimulate the growth of zinc vacancies,which resulted in the formation of defect energy levels,adsorption sites,and an adjusted Fermi level.As a result,the electron transfer behavior between adsorbed CO or H_(2)and the crystal surface varied,which further affected the photocatalytic behavior.The results show that the effect of photothermal synergy may not only produce the expected kinetic energy,but more importantly,produce energy that can change the activation mode of the reactant gas.This study provides a new understanding of the CO catalytic oxidation and reduction processes over semiconductor materials.

Multiple Ionic-Covalent Couplings in Molecules and Clusters

The electronic states of molecules made of electropositive and electronegative components result from the interference between the covalent configurations and the ionic configurations. This work shows complex aspects of these ionic-covalent couplings in small molecules such as Li2H, Li2F, and Li4F. The extension of this type of analysis to the adsorption of the electrophilic molecules on the metal clusters or on the metal surfaces is supposed to lead to a radically new interpretation of the observed physical and chemical properties.

Effect of the Ni size on CH4/CO2 reforming over Ni/MgO catalyst：A DFT study

Carbon deposition is sensitive to the metal particle sizes of supported Ni catalysts in CH_4/CO_2 reforming.To explore the reason of this phenomenon,Ni4,Ni8,and Ni12 which re flect the different cluster thicknesses supported on the MgO(100) slabs,have been employed to simulate Ni/MgO catalysts,and the reaction pathways of CH_4/CO_2 reforming on Nix/MgO(100) models are investigated by density functional theory.The reforming mechanisms of CH_4/CO_2 on different Nix/MgO(100) indicate the energy barriers of CH_4 dissociated adsorption,CH dissociation,and C oxidation three factors are all declining with the decrease of the Ni cluster sizes.The Hirshfeld charges analyses of three steps as described above show only Ni atoms in bottom two layers can obtain electrons from the MgO supporters,and the main electron transfer occurs between adsorbed species and their directly contacted Ni atoms.Due to more electron-rich Ni atoms in contact with the MgO supporters,the Ni/MgO catalysts with small Ni particles have a strong metal particle size effect and lead to its better catalytic activity.

Near-infrared absorbing 2D/3D ZnIn2S4/N-doped graphene photocatalyst for highly efficient CO2 capture and photocatalytic reduction

Hierarchical heterostructure photocatalysts with broad spectrum solar light utilization,particularly in the nearinfrared(NIR)region,are emerging classes of advanced photocatalytic materials for solar-driven CO2 conversion into value-added chemical feedstocks.Herein,a novel two-demensional/three-demensional(2 D/3 D)hierarchical composite is hydrothermally synthesized by assembling vertically-aligned ZnIn2 S4(ZIS)nanowall arrays on nitrogen-doped graphene foams(NGF).The prepared ZIS/NGF composite shows enhancement in photothermal conversion ability and selective CO2 capture as well as solar-driven CO2 photoreduction.At273 K and 1 atm,the ZIS/NGF composite with 1.0 wt%NGF achieves a comparably high CO2-to-N2 selectivity of 30.1,with an isosteric heat of CO2 adsorption of 48.2 kJ mol^-1.And in the absence of cocatalysts and sacrificial agents,the ZIS/NGF composite with cyclability converts CO2 into CH4,CO and CH3 OH under simulated solar light illumination,with the respective evolution rates about 9.1,3.5,and 5.9 times higher than that of the pristine ZIS.In-depth analysis using in-situ irradiated X-ray photoelectron spectroscopy(ISI-XPS)in conjunction with Kelvin probe measurements reveals the underlying charge transfer pathway and process from ZIS to NGF.