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Advances in Materials Physics and Chemistry 2024年第9期14卷 213-234页

作者： Alain second Dzabana Honguelet Abel Dominique Eboungabeka Timothée Nsongo Faculty of Science and Technology Marien Ngouabi University Brazzaville Congo Research Group on Physical Chemical and Mineralogical Properties of Materials Brazzaville Congo Alpha Sciences and Beta Technologies Association Brazzaville Congo Geological and Mining Research Center Brazzaville Congo

This work is a simulation model with the LAMMPS calculation code of an electrode based on alkali metal oxides (lithium, sodium and potassium) using the Lennard Jones potential. For a multiplicity of 8*8*8, we studied a gap-free model using molecular dynamics. Physical quantities such as volume and pressure of the Na-O and Li-O systems exhibit similar behaviors around the thermodynamic ensembles NPT and NVE. However, for the Na2O system, at a minimum temperature value, we observe a range of total energy values;in contrast, for the Li2O system, a minimum energy corresponds to a range of temperatures. Finally, for physicochemical properties, we studied the diffusion coefficient and activation energy of lithium and potassium oxides around their melting temperatures. The order of magnitude of the diffusion coefficients is given by the relation Dli-O >DNa-O for the multiplicity 8*8*8, while for the activation energy, the order is well reversed EaNa-O > EaLi-O.

关键词： Molecular Dynamics Diffusion Coefficients Activation Energy Lithium Oxide Sodium Oxide Lennard Jones Potential Data File Atomic and Charge Models Cathode LAMMPS

Molecular Dynamics, Diffusion Coefficients and Activation Energy of the Electrolyte (Anode) in Lithium (Li and Li⁺), Sodium (Na and Na⁺) and Potassium (K and K⁺)

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Modeling and Numerical Simulation of Material Science 2024年第1期14卷 39-57页

作者： Alain second Dzabana Honguelet Timothée Nsongo Bitho Rodongo Earvin Loumbandzila Faculty of Science and Technology Marien Ngouabi University Brazzaville Congo Research Group on The Physical and Chemical Properties of Materials Brazzaville Congo Association Alpha Sciences Beta Technologies Brazzaville Congo Centre for Geological and Mining Research Brazzaville Congo

This work is a simulation modelling with the LAMMPS calculation code of an electrode based on alkali metals (lithium, sodium and potassium) using the MEAM potential. For different multiplicities, two models were studied;with and without gap. In this work, we present the structural, physical and chemical properties of the lithium, sodium and potassium electrodes. For the structural properties, the cohesive energy and the mesh parameters were calculated, revealing that, whatever the chemical element selected, the compact hexagonal hcp structure is the most stable, followed by the face-centred cubic CFC structure, and finally the BCC structure. The most stable structure is lithium, with a cohesion energy of -6570 eV, and the lowest bcc-hcp transition energy of -0.553 eV/atom, followed by sodium. For physical properties, kinetic and potential energies were calculated for each of the sectioned chemical elements, with lithium achieving the highest value. Finally, for the chemical properties, we studied the diffusion coefficient and the activation energy. Only potassium followed an opposite order to the other two, with the quantities with lacunae being greater than those without lacunae, whatever the multiplicity. The order of magnitude of the diffusion coefficients is given by the relationship DLi > DNa > Dk for the multiplicity 6*6*6, while for the activation energy the order is reversed.

关键词： Molecular Dynamics Diffusion Coefficients Activation Energy Lithium Alkali Metals MEAM Potential

Study on mineral structural stability of marine 1.m manganate

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Acta Oceanologica Sinica 1999年第2期18卷 257-266页

作者： Qian Jiangchu 1. second Insititute of Oceanography, State Oceanic Administration, Hangzhou 31.01., China (Received June 24, 1.96 accepted March 3, 1.98) second Insititute of Oceanography State Oceanic Administration Hangzhou 310012 China

In order to study the phase transformation between 1.m manganate and 0.7nm manganate, a series of Slum Me^(2+) manganates were made after the synthetic 1.m Na^+ manganate substituted with different kinds of divalent cations. The X-ray diffraction analysis of wet S1.m Me^(2+) manganates after 24 h room temperature dry showed that their basal d-spacing had been changed, indicating that there was phase transformation between 1.m and 0.7nm manganates. Take 1.m manganates with unstable structure collapsed into 0. 7nm manganate by losing one interlayer OH-H_2O, while those with stable structure still retained the 1.m d-spacing. This factor reminds us that the manganese nodule samples must be kept in wet condition to avoid the misleading results. The structural stabdity of 1.n manganate is mainly controlled by the interlayer divalent cations. There is a possitive correlation between the amount of cations in the interlayer and the structural stability, while the capacity of different canons in stabilizing the structure of 1.m manganate is as follows: Ni > Cu > Co > Zn > Ca>Mg > Na.

关键词： Manganese nodules 1.m manganate phase transformation structural stability

Representation of microscale ocean wavenumber spectrum correct to the second order

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Science China Earth Sciences 2005年第4期48卷 549-554页

作者： YUAN Yeli2 & HUA Feng1.2,3 1. Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071. China 2. Key Laboratory of Marine Science and Numerical Modeling, State Oceanic Administration, Qingdao 266061. China 3. Graduate School of the Chinese Academy of Sciences, Beijing 1.0039, China 1. Key Laboratory of Marine Science and Numerical Modeling State Oceanic Administration 266061 Qingdao China 2. Institute of Oceanology Chinese Academy of Sciences 266071 Qingdao China 3. Graduate School of the Chinese Academy of Sciences 100039 Beijing China

In this paper, the analytical representations of four wave source functions in high-frequency spectrum range are given on the basis of ocean wave theory and dimensional analysis, and the perturbation method is used to solve the governing equations of ocean wave high-frequency spectrum on the basis of the temporally stationary and locally homogeneous scale relations of microscale wave. The microscale ocean wavenumber spectrum correct to the second order has an explicit structure, its first order part represents the equilibrium between dif- ferent source functions, and its second order part represents the contribution of microscale wave propagation.

关键词： temporally stationary and locally homogeneous, source function in high-frequency spectrum range, microscale ocean wavenumber spectrum.

second-order consensus in networks of dynamic agents with communication time-delays

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Journal of Systems Engineering and Electronics 2010年第1期21卷 88-94页

作者： Bo Yang1.2, Huajing Fang3, and Hua Wang4 1. School of Navigation, Wuhan University of Technology, Wuhan 430063, P. R. China 2. Wuhan second Ship Design and Research Institute, Wuhan 430064, P. R. China 3. Department of Control Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China 4. Department of Aerospace and Mechanical Engineering, Boston University, Boston MA0221., USA School of Navigation Wuhan University of Technology Wuhan 430063 P. R. China Wuhan second Ship Design and Research Institute Wuhan 430064 E R. China Department of Control Science and Engineering Huazhong University of Science and Technology Wuhan 430074 P. R. China Department of Aerospace and Mechanical Engineering Boston University Boston MA02215 USA

This paper proposes second-order consensus protocols with time-delays and gives the measure of the robustness of the protocols to the time-delay existing in the network of agents with second-order dynamics. By employing a frequency domain method, it is proven that the information states and their time derivatives of all the agents in the network achieve consensus asymptotically, respectively, for appropriate communication timedelay if the topology of weighted network is connected. Particularly, a tight upper bound on the communication time-delay that can be tolerated in the dynamic network is found. The consensus protocols are distributed in the sense that each agent only needs information from its neighboring agents, which reduces the complexity of connections between neighboring agents significantly. Numerical simulation results are provided to demonstrate the effectiveness and the sharpness of the theoretical results for second-order consensus in networks in the presence of communication time-delays.

关键词： second-order consensus protocols dynamic networks algebraic graph theory frequency domain analysis com-munication constraints.

Size fractionated biomass and productivity of phytoplankton and new production in the Prydz Bay and the adjacent Indian sector of the Southern Ocean during the austral summer 1.98/1.99

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Acta Oceanologica Sinica 2003年第4期22卷 651-670页

作者： Cai Yuming 1.3, Ning Xiuren 1.2,3, Zhu Genghai3, Shi Junxian3 1. Key Laborary of Submarine Geosciences of State Oceanic Administration,Hangzhou 31.01.,China. 2. Key Laborary of Ocean Dynamic Processes and Satellite Oceanography of State Oceanic Administration,Hangzhou 31.01.,China 3. second Institute of Oceanography of State Oceanic Administration, Hangzhou 31.01.,China Key Lab Submarine Geosci State Ocean Adm Hangzhou 310012 Peoples R China Key Lab Ocean Dynam Proc Satellite Oceanog State Ocean Adm Hangzhou 310012 Peoples R China Inst Oceanog State Ocean Adm 2 Hangzhou 310012 Peoples R China

The paper deals with the studies on the cell abundance, the composition of dominant species, size fractionated biomass and productivity of phytoplankton, new production, the environmentally restricted mechanism in the Prydz Bay and the adjacent Indian sector of the Southern Ocean during the austral summer 1.98/1.99. The results showed that there was marked feature of spatial zonation in the sea areas investigated. In the Prydz Bay and its adjacent continental shelf, the biomass and productivity of phytoplankton were high; those of continental slope and open ocean area were obviously low. The nutrient concentration had opposite distribution trend, due to the consumption of phytoplankton. It mainly affected by the vertical stability of water column, grazing pressure of zooplankton, temperature and light etc. The results of size-fractionation showed that the average contribution of netplankton to total chlorophyll a in studied sea areas was 52.2 %, those of nano- and picoplankton were 29.4 % and 1..4 %, respectively. The average contribution of netplankton to total primary production was 52.4 %, those of nano- and picoplankton were 28.7 % and 1..9 %, separately. It is same as previous conclusion that the contribution of picoplankton to productivity is slightly larger than that to biomass of phytoplankton communities. The average new production and f-ratio were 230.6 mg/ (m(2.)d) and 0.43, respectively.

关键词： phytoplankton standing stock primary productivity size-fractionation new production the Southern Ocean

Large second-order optical nonlinearities of s-triazine derivatives: View from micro molecules to macro crystals

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Science China Chemistry 2005年第3期48卷 203-209页

作者： FANG Qi1. LEI Hong2, CUI Yuezhi3, HUANG Zhenli4, XUE Gang1.& YU Wentao1.1. State Key Laboratory of Crystal Materials, Shandong University, Jinan 2501.0, China 2. School of Information Science and Engineering, Shandong University, Jinan 2501.0, China 3. Department of Chemical Engineering, Light Industry College of Shandong, Jinan 2501.0, China 4. Key Laboratory of Biomedical Photonics, Ministry of Education, Huazhong University of Science and Technology, Wuhan 430074, China 1. State Key Laboratory of Crystal Materials Shandong University 250100 Jinan China 2. School of Information Science and Engineering Shandong University 250100 Jinan China 3. Department of Chemical Engineering Light Industry College of Shandong 250100 Jinan China 4. Key Laboratory of Biomedical Photonics Ministry of Education Huazhong University of Science and Technology 430074 Wuhan China

Three s-triazine derivatives have been synthesized and their structures been de-termined. These are Compound I: 2,4-dimethyl-6-(p-N,N-dimethylaminostyryl)-s-triazine (abbre-viated to NMe-1., Compound II: 2,4-dimethyl-6-(p-N,N-diethylaminostyryl)-s-triazine (to NEt-1., and Compound III: 2-methyl-4,6-bis(p-N,N-dimethylaminostyryl)-s-triazine (NMe-2). NMe-1.and NEt-1.molecules belong to the D-π-A type with a one-dimensional charge-transfer character. NMe-1.crystallizes to centrosymmetric P1.space group, while NEt-1.to non-centrosymmetric polar Cc space group with all of the molecular charge-transfer axes taking the same orientation. Under the irradiation of 1.64 nm fundamental laser, NEt-1.powder crystals radiate a 2-order harmonic light with an intensity 46.8 times that of urea. The Λ typed NMe-2 molecule, which has a two-dimensional charge-transfer character, crystallizes to polar P21.space group. Its powder crystals exhibit a 2-order harmonic intensity 46.2 times that of urea. The quantum chemical cal-culations and tensor analyses have been carried out to reveal the dependence of the macro 2-order nonlinear optical (NLO) efficiency on the micro 2-order NLO coefficients (β) and on the crystalline packing styles.

关键词： s-triazine derivatives, synthesis, structure, SHG intensities of crystals, βvalues of molecules.

Preparation and Enhanced Daylight-Induced Photo-Catalytic Activity of Transparent C-Doped TiO_2 Thin Films

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Journal of Wuhan University of Technology(Materials Science) 2010年第5期25卷 738-742页

作者：白爱英 College of Materials Science and Engineering Taiyuan University of Technology Xin Zhou Vocational Technical College

The transparent C-doped TiO2 nanostructure films were fabricated on the silicate glass substrates by sol-gel spin-coated method. The as-prepared films were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, UV-visible absorption spectra （UV-vis） and X-ray photoelectron spectroscopy （XPS）. The photocatalytic activity was evaluated via the photocatalytic oxidation of methylene blue in aqueous under daylight irradiation at room temperature. The results show that the daylight-induced photocatalytic activities of the as-prepared films are improved by the C-doping. The calcination temperatures significantly affect the morphology, microstructure and photocatalytic activity of the as-prepared samples. At 723 K, the C-doped TiO2 films exhibit the highest photocatalytic activity due to the synergetic effects of good crystallization, appropriate oxygen vacancies and strong absorption in the near UV and visible-light region.

关键词： C-doped TiO2 films daylight-induced photocatalytic activity spin-coated

A modified multi-reference second order perturbation theory

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中国科学：化学英文版 2010年第4期53卷 933-939页

作者： LI AnYang1. HAN HuiXian2, SUO BingBing3, WANG YuBin3 & WEN ZhenYi3 1.nstitute of Computational Chemistry, Chongqing University of Post and Telecommunications, Chongqing 400065, China 2Department of Physics, Northwest University, Xi’ an 71.069, China 3Institute of Modern Physics, Northwest University, Xi’ an 71.069, China 1. Institute of Computational Chemistry Chongqing University of Post and Telecommunications Chongqing 400065 China2. Department of Physics Northwest University Xi’ an 710069 China3. Institute of Modern Physics Northwest University Xi’ an 710069 China

A new scheme with extended model space is proposed to improve the calculation of multi-reference second order perturbation theory (MRPT2). The new scheme preserves the concise code structure of the original program, and avoids intruder states in constructions of the potential energy surface, which is confirmed by a series of comparable calculations. The new MRPT2 program is an available tool for the research of molecular excited states and electronic spectrum.

关键词： perturbation theory multi-reference intruder state

Variation of reactivity of particulate and sedimentary organic matter along the Zhujiang River Estuary

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Acta Oceanologica Sinica 2003年第4期22卷 557-568页

作者： Chen Jianfang 1.2, Jin Haiyan 1.2, Yin Kedong3, Li Yan 1.2 1. Key Laboratory of Submarine Geosciences of State Oceanic Administration, Hangzhou 31.01., China. 2. Laboratory of Regional Oceanography, second Institute of Oceanography, State Oceanic Aedministration, Hangzhou,31.01., China 3. Department of Biology, Hong Kong University of Science and Technology, Hong Kong Kay Lab Submarine Geosci State Ocean Adm Hangzhou 310012 Peoples R China State Ocean Adm Inst Oceanog 2 Lab Reg Oceanog Hangzhou 310012 Peoples R China Hong Kong Univ Sci & Technol Dept Biol Hong Kong Hong Kong Peoples R China

To investigate organic matter source and reactivity in the Zhujiang River (Pearl River) Estuary and its adjacent areas, particulate organic carbon (POC), particulate hydrolysable amino acids (PHAA), and Chl a during two cruises in July 1.99 and July 2000 were measured. The highest POC and PHAA concentration was observed in the waters with maximum Chl a. The spectra distribution, relative content (dry weight in milligram per gram), PHAA-C% POC and other indicators such as the ratios of amino acids vs. amino sugars (AA/AS) and glucosamine vs. galactosamine (Glum/Gal) suggested that particulate amino acids in the water column and sediments in the Zhujiang River Estuary were mainly derived from biogenic processes rather than transported from terrestrial erosion. In inner estuary where high turbidity was often observable, organic matter was mainly contributed by re-suspension of bottom sediments with revealed zooplankton, microbial reworked characteristics, which suggest that these organic matters were relatively 'old'. In the estuarine brackish region, organic matter in water column is mainly contributed by relatively fresh, easily degradable phytoplankton derived organic matter. During physical - biological processes within the eastuary, organic matter derived from phytoplankton was subjected to alteration by zooplankton grazing and bacterial reworking.

关键词： organic matter reactivity amino acids the Zhujiang River Estuary