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Monte Carlo Simulation on Energy Deposition of Low-Energy Electrons in Liquid Water

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Chinese Physics Letters 2005年第1期22卷 91-94页

作者：谭震宇夏曰源赵明文刘向东黄博达李峰季燕菊 SchoolofElectricalEngineering ShandongUniversityJinan250061 SchoolofPhysicsandMicroelectronics ShandongUniversityJinan250100 SchoolofInformationScienceandEngineering ShandongUniversityJinan250100

A Monte Carlo approach to simulate the transport and energy deposition of low energy electrons (E10 ≤ 10keV) in liquid water is presented. The elastic scattering of electrons is described by Mott cross section, which is derived from the relativistic wave equation of Dirac. The inelastic scattering model of electrons is based on the dielectric response theory with exchange effect included. A new method of sampling various inelastic scattering events is proposed in the simulation. Using the approach stated, the spatial distribution of inelastic scattering events and energy deposition of electrons in liquid water are computed and the results are compared with other theoretical studies.

关键词：蒙特卡洛仿真能量沉积低能电子液态水

Collisional　Reactions　of　Energetic　Methane　Molecules　with　Single-Walled　Carbon　Nanotubes

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Chinese Physics Letters 2004年第6期21卷 1044-1047页

作者： LIFeng XIAYue-Yuan ZHAOMing-Wen LIUXiang-Dong HUANGBo-Da TANZhen-Yu JIYan-Ju SchoolofPhysicsandMicroelectronics ShandongUniversityJinan250100 SchoolofInformationScienceandEngineering ShandongUniversityJinan250100 SchoolofElectricalEngineering ShandongUniversityJinan250161

We study the collisions of energetic methane molecules with single-walled carbon nanotubes in the incident energy range from 5 to 100 eV using classical molecular dynamics simulations combined with ab initio calculations. The methane molecules can be decomposed into different hydrocarbon radicals, e. g. CHn (n = 1-3), in the collisions depending on the incident energy. Chemical functionalization of the single-walled carbon nanotubes resulting from the chemical adsorption of these hydrocarbon radicals on the outside wall of single-walled carbon nanotubes can be achieved simultaneously. Some stable adsorption configurations of hydrocarbon-functionalized single-walled carbon nanotubes are also presented based on ab initio calculations.

关键词： Molecular dynamics

Single-Walled Carbon Nanotubes Acting as Controllable Transport Channels

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Chinese Physics Letters 2004年第12期21卷 2388-2391页

作者：黄博达夏曰源赵明文李峰刘向东季燕菊宋晨谭震宇刘辉 SchoolofInformationScienceandEngineering ShandongUniversityJinanShandong250100 SchoolofPhysicsandMicroelectronics ShandongUniversityJ/nan250100 SchoolofElectricalEngineering ShandongUniversityJinan250100 HighPerformanceComputingCentre ShandongUniversityJinan250100

The motion and equilibrium distribution of water molecules adsorbed inside neutral and negatively charged single-walled carbon nanotubes (SWNTs) have been studied using molecular dynamics simulations (MDSs) at room temperature based on CHARMM (Chemistry at HARvard Molecular Mechanics) potential parameters. We find that water molecules have a conspicuous electropism phenomenon and regular tubule patterns inside and outside the charged tube wall. The analyses of the motion behaviour of water molecules in the radial and axial directions show that by charging the SWNT, the adsorption efficiency is greatly enhanced, and the electric field produced by the charged SWNTs prevents water molecules from flowing out of the nanotube. However, water molecules can travel through the neutral SWNT in a fluctuating manner. This indicates that by electrically charging and uncharging the SWNTs, one can control the adsorption and transport behaviour of polar molecules in SWNTs for using as a stable storage medium or long transport channels. The transport velocity can be tailored by changing the charge on the SWNTs, which may have a further application as modulatable transport channels.

关键词： Molecules

Effect of Cationic Surfactant on the Inhibition of Ligninase by Hydrogen Peroxide

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Chinese Chemical Letters 2003年第8期14卷 836-839页

作者： ZhuanNiYU XiRong,HUANG ShaoFangSONG DanWANG XueMeiLU YueZhongLI YinBoQU PeiJiGAO KeyLabforColloidandInterfaceChemistryoftheEducationMinistryofChina ShandongUniversityJinan250100 KeyLabforColloidandInterfaceChemistryoftheEducationMinistryofChina ShandongUniversityJinan250100 StateKeyLabofMicrobialTechnologyOfChina ShandongUniversityJinan250100 StateKeyLabofMicrobialTechnologyOfChina ShandongUniversityJinan250100

The inhibition of ligninase by hydrogen peroxide in the presence of cationic surfactant CTAB was studied by kinetic spectrophotometric technique. Results showed that addition of CTAB enhanced the inhibition by H2O2, but it did not alter the inhibition pattern and the inhibition constant changed little with the concentration of CTAB. Modification of the enzymic protein by the surfactant monomer may be responsible for the above mentioned results.

关键词： Ligninase hydrogen peroxide cationic surfactant inhibitory kinetics veratryl alcohol.

Polaronic Tunnelling in Organic Triblock Copolymers

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Chinese Physics Letters 2005年第1期22卷 178-181页

作者：刘德胜张大成解士杰梅良模 SchoolofPhysicsandMicroelectronics ShandongUniversityJinan250100//DepartmentofPhysicsJiningNormalUniversityJining272025//NationalKeyLaboratoryofCrystalMaterialsShandongUniversityJinan250100 SchoolofPhysicsandMicroelectronics ShandongUniversityJinan250100//NationalKeyLaboratoryofCrystalMaterialsShandongUniversityJinan250100

Polaron tunnelling is studied in xPA/nPPP/xPA (PA for polyacetylene and PPP poly (p-phenylene)) triblock copolymer, which has a well-barrier-well structure. An extended tight-binding Hamiltonian including external electric held is adopted. Without electric field, the injected electrons would not extend over the whole copolymer chain but instead be confined in the segments of PA. This is different from the behaviour of the traditional semiconductors. It is found that the polaron can transfer to the potential barrier-PPP segment when the applied electric field reaches a certain value. The critical polaron tunnelling electric fields depend upon the lengths of PPP segments.

关键词： ELECTRONIC-STRUCTURE CONJUGATED POLYMERS BAND-GAP ELECTROLUMINESCENCE POLYACETYLENE OLIGOMERS STATES oligomers Electronic structure Electric fields Organic polymers Electrochemiluminescence Band gap Electroluminescence polarons Segments Countries (nations) Tunneling Polyacetylenes Copolymers Nylons

Generation of Hydrogen from Photolysis of Organic Acids by Photosynthetic Bacteria

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Chinese Chemical Letters 2002年第11期13卷 1111-1114页

作者： SuPingYANG ZhengWuWANG 等 StateKeyLaboratoryofMicrobialTechnology ShandongUniversityJinan250100 KeyLabofColloidandInterfaceChemistryforStateEducationMinistry ShandongUniversityJinan250100

Photodecomposition of ten kinds of organic acids by Rhodopseudomonas palustris for producing hydrogen has been investigated. By using acetate as hydrogen donor, dynamics of hydrogen production and cell growth has been determined; the influences of acetate concentration, temperature, light intensity and the effects of the interaction among metal ions (Fe3+, Ni2+), acetate and glutamate in aqueous solution on hydrogen production have been examined for optimizing the conditions of H2 generation. The results show that H2 production is partially correlated with cell growth; Ni2+ inhibits hydrogen production, but enhances cell growth; Fe3+ promotes hydrogen production evidently. The highest rate of H2 production is 22.1 mL L-1 h-1 under the conditions of 35 ~ 37℃, 6000 ~ 8000 lx, 30 mmolL-1 of acetate, 9 mmolL-1 of glutamate, and 50 mmolL-1 of Fe3+.

关键词： Photodecomposition of organic acids hydrogen photosynthetic bacteria.

Degradation characteristics of two Bacillus strains on the Microcystis aeruginosa

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Journal of Environmental Sciences 2005年第2期17卷 205-207页

作者： PEIHai-yan HUWen-rong QUYin-bo MURui-min LIXiao-cai StateKeyLaboratoryofMicrobiology ShandongUniversityJinan250061China SchoolofEnvironmentScienceandEngineering ShandongUniversityJinan250061China

The degradation kinetics of strains P05 and P07 and the degradation effects of mixed strain on Microcystis aeruginosa were studied. The results showed that: (1) The degradation processes of strains P05 and P07 on Microcystis aeruginosa accorded with the first-order reaction model when the range of Chl-a concentration was from 0 to 1500 μg/L. (2) The initial bacterium densities had a strong influence on the degradation velocity. The greater the initial bacterium density was, the faster the degradation was. The degradation velocity constants of P05 were 0.1913, 0.2175 and 0.3092 respectively, when bacterium densities were 4.8×10 5, 4.8×10 6, 2.4×10 7 cells/ml. For strain P07, they were 0.1509, 0.1647 and 0.2708. The degradation velocity constant of strain P05 was higher than that of P07 when the bacterium density was under 4.8×10 5 cells/ml, but the constant increasing of P07 was quicker than that of P05. (3) The degradation effects of P05 and P07 strains did not antagonize. When the concentration of Chl-a was high, the degradation effects of mixed strain excelled that of any single strains. But with the decrease of the Chl-a concentration, this advantage was not clear. When the concentration was less than 180 μg/L, the degradation effects of mixed were consistent with that of strain P07.

关键词： Bacillus sp. Microcystis aeruginosa characteristic degradation kinetics velocity constant

In Situ Fabrication of ZnS Semiconductor Nanoparticles in Layered Organic-inorganic Solid Template

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Chinese Chemical Letters 2004年第1期15卷 97-100页

作者： BaoLinZHU XiaoCHEN ZhenMingSUI LiMeiXU ChunJieYANG JiKuanZHAO JieLIU KeyLabforColloidandInterfaceChemistryofEducationMinistry ShandongUniversityJinan250100 KeyLabforCrystalMaterial ShandongUniversityJinan250100

Ordered ZnS semiconductor nanoparticles were in situ synthesized in metal halide perovskite organic/inorganic layered hybrids (CnH2n+1NH3)2ZnCl4 (n=10 and 12) by reaction of their spin-casting films with H2S gas. Transmission electron microscopy, UV-vis spectroscopy and small-angle X-ray diffraction were used to characterize the morphology and the structure of formed nanoparticles. Obtained results indicate an effective way to incorporate functional inorganic nanoparticles into structured organic matrices.

关键词： Layered solid template in situ fabrication ZnS nanoparticles.

A Peptide-mediated Fenton Reaction in Wood-degrading Fungi

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Chinese Chemical Letters 2002年第8期13卷 773-776页

作者： WeiWANG JunChengLIU 等 TheStateKeyLaboratoryofMicrobialTechnology ShandongUniversityJinan250100 InstituteofColloidalandInterfaceChemistry ShandongUniversityJinan250100

Gt factor is a low-molecular-weight peptide isolated from the extracellular culture of wood-degrading fungus Gloeophyllum trabeum. It is capable of enhancing degradation of cellulose. Its action mechanism was investigated and it was found that Gt factor could reduce Fe3+ to Fe2+. Electron paramagnetic resonance (EPR) spectroscopy revealed in the presence of O2, Gt factor could drive the formation of H2O2 via a superoxide anion O2.- intermediate and mediate the generation of hydroxyl radical HO˙ in a Fenton-type reaction. All these provided evidence for the formation of HO˙ in some wood-degrading fungi.

关键词： Cellulose degradation hydroxyl radical HO˙ Gt factor electron paramagnetic resonance.