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Preparation and Characterization of Nanocomposite MgFe_2O_4/SiO_2

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Journal of Wuhan University of technology(Materials Science) 2009年第3期24卷 354-358页

作者：徐莉 College of Science Nanjing Forestry University

Nanocomposites MgFe2O4/SiO2 were successfully synthesized by the sol-gel method in the presence of N, N-dimethylformamide （DMF）. The formation of pure MgFe2O4 was confirmed by powder X-ray diffraction （XRD） and electron diffraction. The structural evolution of MgFe2O4 nanocrystals was followed by powder X-ray diffraction and IR absorption spectroscopy. The formation of spinel structure of MgFe2O4 started at 800 ℃, and completed at 900 ℃, The transmission electron microscopy （TEM） measurements suggest that the particle sizes increase with the increasing annealing temperature, and the mean particle sizes of the spherical samples annealed at 800 ℃, 900 ℃ and 1 050 ℃ are ca. 3 nm, 8 nm and 11 nm, respectively. Magnetization measurements at room temperature and 78 K indicate supemaramagnetic nature of these MgFe2O4 nanocrvstals.

关键词： nanocomposite sol-gel magnesium ferrite magnetic property

Effects of chlorothalonil and carbendazim on nitrification and denitrification in soils

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Journal of Environmental Sciences 2009年第4期21卷 458-467页

作者： LANG Man, CAI Zucong state key laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences,nanjing 210008, china [a]state key laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China

The effects of chlorothalonil and carbendazim on nitrification and denitrification in six soils in upland and rice paddy environments were investigated. laboratory aerobic （60% water holding capacity） and anaerobic （flooded） conditions were studied at 25℃ and fungicide addition rates of 5.5 mg/kg A. I. （field rate, FR）, 20 times （20FR） and 40 times （40FR） field rate, respectively. The results indicated that chlorothalonil at the field rate had a slight inhibitory effect on one soil only, and that soil did not nitrify much in the first place. But chlorothalonil at higher rates inhibited nitrification significantly in all soils. For soils JXP and JXU with a pH of less than 5.0, chlorothalonil almost completely stopped their nitrification at 20FR and 40FR during the whole 14 d incubation period. For soils HNP and HNU with a pH of greater than 8.0, chlorothalonil also significantly inhibit nitrification at 20FR and 40FR （p 〈 0.05）. However, NH4＋ that was added to the soil was also almost completely nitrified by the end of the incubation period in these two soils. The effects of chlorothalonil at 20FR and 40FR on the nitrification of JSP and JSU soils, with a pH of 5.4 and 7.2, respectively, were intermediate between the other soil types. Chlorothalonil had no effect on denitrification at the field rate and had little effect at the higher rates of application in some soils. Carbendazim had essentially no effect on nitrification and denitrification in soils assessed.

关键词： fungicide nitrification denitrification chlorothalonil carbendazim

Preparation,Structure and Dielectric Properties of Tungsten Bronze Ferroelectrics in SrO-Eu_2O_3-TiO_2-Nb_2O_5 System

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Journal of Wuhan University of technology(Materials Science) 2011年第2期26卷 312-315页

作者：胡长征 state laboratory Breeding Base of Nonferrous Metals and Specific Materials Processing Guilin University of Technology key laboratory of Nonferrous Materials and New Processing technology Ministry of EducationGuilin University of Technology state key laboratory of Advanced technology for Materials Synthesis and Processing Wuhan University of Technology

Compounds Sr4Eu2Ti4Nb6O30 and Sr5EuTi3Nb7O30 with filled tetragonal tungsten bronze structure were prepared,and the dielectric characteristics and ferroelectric transition were *** ceramics displayed weak frequency dependence in room temperature dielectric constant,which decreased from 125 to 118 for Sr4Eu2Ti4Nb6O30,from 206 to 195 for Sr5EuTi3Nb7O30 in the frequency range of 10 kHz to 1 *** present ceramics showed a diffuse ferroelectric phase *** frequency independent transition temperature （Tm） indicated the above compounds had no relaxor *** diffuseness （γ） was 1.45 and 1.64 for Sr4Eu2Ti4Nb6O30 and Sr5EuTi3Nb7O30 *** weak ferroelectric of the present materials are indicated from the P-E hysteresis loops,and a small 2Pr of 0.596 μC/cm2 and 0.068 μC/cm2 were observed for Sr4Eu2Ti4Nb6O30 and Sr5EuTi3Nb7O30 respectively.

关键词： tungsten bronze dielectric properties X-ray diffraction phase transition

Preparation of Oriented Barium Titanate Thin Films by Combination of Electrophoretic Deposition with Hydrothermal Treatment

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Journal of Materials Science & technology 2010年第11期26卷 996-1000页

作者： Lihong Xue and Youwei Yan state key laboratory of Materials Processing and Die and Mould technology,Huazhong University of Science and technology,Wuhan 430074,china [a] state key laboratory of Materials Processing and Die and Mould technology Huazhong University of Science and technology Wuhan 430074 china

Highly oriented barium titanate （BaTiO 3） thin films on Pt substrate were fabricated by combination of electrophoretic deposition with hydrothermal *** structure and morphology of thin films were characterized by X-ray diffraction and field-emission scanning electron *** is found that the titania precursor film,Ba（OH）2 concentration and hydrothermal temperature play crucial roles in the film morphology and *** BaTiO3 thin films with highly （110） preferred orientation can be formed on polycrystalline Pt substrate by appropriate adjustment of the reaction *** orientation parameter f of highly oriented BaTiO3 films was up to *** films exhibited a smooth and crack-free surface and remained in the layered *** situ topotactic transformation and dissolution-crystallization mechanisms were proposed to explain the morphology and orientation of BaTiO3 films during hydrothermal treatment.

关键词： Barium titanate Preferred orientation Electrophoretic deposition Hydrothermal treatment

Study on specific interaction of new ferrocene-substituted carborane conjugates with hemoglobin protein

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Science china Chemistry 2012年第4期55卷 594-603页

作者： WU ChunHui1,3, YE HongDe2, JIANG Hui1, WANG XueMei1 & YAN Hong2 1state key Lab of Bioelectronics (Chien-Shiung Wu Lab), Southeast University, nanjing 210096, china 2state key laboratory of Coordination Chemistry School of Chemistry and Chemical Engineering, nanjing University, nanjing 2.0093. china 3School of Life Science and technology, University of Electronic Science and technology of china, Chengdu 610054, china 1. state key Lab of Bioelectronics (Chien-Shiung Wu Lab) Southeast University Nanjing 210096 China3. School of Life Science and Technology University of Electronic Science and Technology of China Chengdu 610054 China2. State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical Engineering Nanjing University Nanjing 210093 China

The interactions between the new organometallic complexes, ferrocenesubstituted dithioocarborane conjugates （denoted as FcSB1, FcSB2 and FcSBCO） and hemoglobin （Hb） are investigated by electrochemistry, fluorescence and UVvis absorption spectroscopy. The results demonstrate that FcSB1, FcSB2 and FcSBCO can bind to the heme iron center through the replacement of the weakly bound H20/02 in the distal heme pocket of Hb by their sulfur donor atoms, inducing the allosteric change from the R state （oxygenated conformation, relax） to T state （deoxygenated conformation, tense）. The binding affinity is in the order of FcSBCO〉FeSB2〉FeSB1. Moreover, the fluorescence study illustrates that the three ferrocenecarborane conjugates differently affect the quarterly and tertiary structures as well as the polarity in the surrounding of the Trp and Tyr residues in Hb. Typically, FcSB2 mainly induces alterations of the microenvironment around the 1337Trp residue which is located on the cql32 interface of Hb. Such distinct influences are attributed to the structural features of FcSB1, FcSB2 and FcSBCO containing hydrophobic ferrocenyl and carboranyl units as well as C=O group. Screening the proteinbinding behavior can signify the potential bioactivity of such molecules and may be helpful in the future development of promising multifunctional metallodrugs.

关键词： fluorescence – UV vis absorption spectroscopy – differential pulse voltammetry – biomolecular interaction – ferrocene substituted carborane conjugates – hemoglobin

Phytotoxicity of four herbicides on Ceratophyllum demersum,Vallisneria natans and Elodea nuttallii

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Journal of Environmental Sciences 2009年第3期21卷 307-312页

作者： PAN Huiyun,LI Xiaolu,XU Xiaohua,GAO Shixiang state key laboratory of Pollution Control and Resource Reuse,School of the Environment,nanjing University,nanjing 2.0093.china. [a]state key laboratory of Pollution Control and Resource Reuse School of the Environment Nanjing University Nanjing 210093 China

The physiological effects of 4 herbicides （butachlor, quinclorac, bensulfuron-methyl and atrazine） on 3 submerged macrophytes （Ceratophyllum demersum, Vallisneria natans and Elodea nuttallii） were tested in laboratory. The variables of the relative growth rate and the photosynthetic pigment content showed that all of the tested herbicides affected the growth of the plants obviously, even at the lowest concentration （0.0001 mg/L）. Except for the C. demersum treated with quinclorac at 0.005 and 0.01 mg/L, the relative growth rates of the plants were inhibited significantly （p 〈 0.01）. Statistical analysis of chlorophyll a （Chl-a） contents was carded out with both the t-test and one-way ANOVA to determine the difference between the treatment and control. The results showed that Chl-a contents of the plants in all treatment groups were affected by herbicides significantly, except for the C. demersum treated with bensulfuron-methyl at 0.0005 mg/L. The decrease in Chl-a content was positively correlated to the dosage of the herbicides in most treatment groups. It was suggested that herbicides in water bodies might potentially affect the growth of aquatic macrophytes. Since the Chl-a content of submerged macrophytes responded to the stress of herbicides sensitively and directly, it could be used as a biomaker in environmental monitoring or in the ecological risk assessment of herbicide contamination.

关键词： phytotoxicity herbicides submerged macrophyte ecological risk assessment

CHARACTERISTICS OF FLOW RESISTANCE IN OPEN CHANNELS WITH NON-SUBMERGED RIGID VEGETATION

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Journal of Hydrodynamics 2008年第2期20卷 239-245页

作者： WU Fu-sheng nanjing Hydraulic Research Institute Nanjing 210029 China state key laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing 210029 China

The flow resistance factors of non-submerged rigid vegetation in open channels were analyzed. The formulas of drag coefficient CD and equivalent Manning＇s roughness coefficient na were derived by analyzing the force of the flow of non-submerged rigid vegetation in open channel. The flow characteristics and mechanism of non-submerged rigid vegetation in open channel were studied through flume experiments.

关键词： characteristics of flow resistance non-submerged rigid vegetation drag coefficient equivalent Manning's roughness coefficient

WAVE-CURRENT INTERACTIONS WITH THREE-DIMENSIONAL FLOATING BODIES

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Journal of Hydrodynamics 2010年第2期22卷 229-240页

作者： LIU Zhen TENG Bin NING De-zhi GOU Ying state key laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024China state key laboratory of Satellite Ocean Environment Dyamics Hangzhou 310012 China

A Time-domain Higher-Order Boundary Element Method（THOBEM） is developed for simulating wave-current interactions with 3-D floating *** a Taylor series expansion and a perturbation procedure,the model is formulated to the first-order in the wave steepness and in the current velocity,*** boundary value problem is decomposed into a steady double-body flow problem and an unsteady wave ***-order boundary integral equation methods are then used to solve the proposed problems with a fourth-order Runge-Kutta method for the time *** artificial damping layer is adopted to dissipate the scattering *** from the other time-domain numerical models,which are often focused on the wave-current interaction with restrained bodies,the present model deals with a floating *** numerical results of wave forces,wave run-up and body response are all in a close agreement with those obtained by frequency-domain *** proposed numerical model is further applied to investigate wave-current interactions with a floating body of complicated *** this work,the regular and focused wave combined with current interacting with a truss-spar platform is investigated.

关键词： wave-current interaction floating bodies time-domain simulation Time-domain Higher-Order Boundary Element Method(THOBEM)

A modified method for simulating non-stationary multi-point earthquake ground motion

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Earthquake Engineering and Engineering Vibration 2010年第2期9卷 201-211页

作者： Li Minggao,Li Xin and Zhou Jing state key laboratory of Coastal and Offshore Engineering,Dalian University of technology,Dalian 116024,china state key laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China

A spectral-representation-based algorithm is proposed to simulate non-stationary and stochastic processes with evolutionary power,according to a prescribed non-stationary cross-spectral density matrix. Non-stationary multi-point seismic ground motions at different locations on the ground surface are generated for use in engineering applications. First,a modified iterative procedure is used to generate uniformly modulated non-stationary ground motion time histories which are compatible with the prescribed power spectrum. Then,ground motion time histories are modeled as a non-stationary stochastic process with amplitude and frequency modulation. The characteristic frequency and damping ratio of the Clough-Penzien acceleration spectrum are considered as a function of time in order to study the frequency time variation. Finally,two numerical examples are presented to validate the efficiency of the proposed method,and the results show that this method can be effectively applied to the dynamic seismic analysis of long and large scale structures.

关键词： multi-support excitation spatial correlation power spectrum-compatibility non-stationary ground motion simulation