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Denitrification in tidal flat sediment, Yangtze estuary

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science China Chemistry 2007年第6期50卷 812-820页

作者： WANG DongQi1,2, CHEN ZhenLou1, XU ShiYuan1, DA LiangJun1, BI ChunJuan1 & WANG Jun1 1 school of Resources and Environment science, east China Normal {3., shanghai 200062, China 2.school of Life science, east China Normal {3., shanghai 200062, China 1. school of Resources and Environment science East China Normal University Shanghai 200062 China 2. school of Life science East China Normal University Shanghai 200062 China

Sediment denitrification rates at six Yangtze River estuary tidal flat locations(mudflats and salt marshes)were measured from July 2003.to October *** winter and summer,spatial distribution of denitrification rates was not great in the Yangtze estuary,while in spring and autumn,denitrification rates had a great spatial distribution because of the human activity *** temporal change of denitrification rates was *** ranged from 0.2 to 3..4 umolN·m^(-2)·h^(-1),and were higher in the *** annual average of sediment denitrification rate was 18.2±12.3.mu molN · m^(-2)· h^(-1)in the middle tidal flat and 15.1 ±9.45 mu molN·m^(-2)·h^(-1)in the low tidal flat in the Yangtze *** analysis indicated that the temperature was the primary factor controlling the process of denitrification(significant positive correlation,P<0.01);at the same time,the content of sediment total nitrogen(TN)and the molar ratio of sediment carbon and nitrogen(C/N)had significant positive correlation(P<0.05)and negative correlation(P<0.05)with denitrification rates,*** the Yangtze estuary,increasing of water salinity had no significant inhibition of denitrification because of the wide change range of water salinity.

关键词： Yangtze estuary, tidal flat sediment, denitrification, effect factors

Algorithm of graph isomorphism with threedimensional DNA graph structures

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Progress in Natural science:Materials International 2005年第2期15卷 86-89页

作者： LIU Guangwu 1,2*, YIN Zhixiang 1,3. XU Jin1 and DONG Yafei1(1. Department of Control science and Engineering, Hua Zhong university of science and {3., Wuhan 43.074, China 2. College of Transportation, Wuhan university of {3., Wuhan 43.063. China 3. Department of Mathematics and Physics, Anhui university of science and {3., Huainan 23.001, China) Department of Control science and Engineering Hua Zhong University of Science and Technology Wuhan 430074 China. College of Transportation Wuhan University of Technology Wuhan 430063 China. Department of Mathematics and Physics Anhui University of Science and Technology Huainan 232001 China

An algorithm for solving the graph isomorphism problem with 3.D DNA structures is proposed in this paper. The k-armed branched junction molecules are used to code k-degree vertices. Double stranded molecules are used to code edges. Then the molecules are mixed in a tube to be ligated. The result can be detected by gel electrophoresis. The time complexity of the algorithm is O(n2), where n is the number of vertices of the graph.

关键词： DNA computing DNA graph structure graph isomorphism

Sol-gel Preparation and Infrared Radiation Property of Boron-substituted Cordierite Glass-ceramics

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Journal of Materials science & technology 2010年第5期26卷 445-448页

作者： Shuming Wang and Fenghua Kuang school of Materials science and Engineering,university of science & technology Beijing,Beijing 100083.China [a] school of Materials science and Engineering university of science & technology Beijing Beijing 100083 China

Boron for aluminum substitution in the cordierite structure has been examined by sol-gel preparation of different samples along the compositional junction Mg2Al4-xBxSi5O18 with x=0,0.5,1,*** increasing the x value from 0 to 1.5 the crystallization behavior changed *** amount B2O3.doping can promote the sintering of amorphous cordierite gel,effectively restrain the precipitation of μ-cordierite and enhance the crystallization of α-*** substitution of B3. for Al3. in cordierite crystal structure can effectively improve the near-infrared spectral emissivity of this cordierite based glass-ceramics.

关键词： Sol-gel Glass-ceramics Infrared radiation B3. substitution Solid solution

Secure communication by generalized chaotic synchronization

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Journal of university of science and technology Beijing 2003年第2期10卷 75-78页

作者： Lequan Min, Xianhua Zhang, and Miao YangApplied science school, university of science and technology Beijing, Beijing 100083. China Applied science school University of Science and Technology Beijing Beijing 100083 China

Chaotic communication is a rather new and active field of research. Althoughit is expected to have promising advantages, some investigators provide evidences that chaoticcommunication is not safety. This letter provides a new chaotic secure communication scheme based ona generalized synchronization theory of coupled system. The secret message hidden in the chaoticsource signal generated via the scheme is very difficult to be unmasked by so-called nonlineardynamic forecasting technique. One example for Internet communications was presented to illustratethe security of our scheme.

关键词： secure communication generalized chaotic synchronization Internet

Sorption of a triazol derivative by soils: importance of surface acidity

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Journal of Environmental sciences 2003年第3期15卷 383-387页

作者： WU De-yi (school of Environmental science and Engineering, shanghai Jiaotong {3., shanghai 2.02.0, China.) school of Environmental science and Engineering Shanghai Jiaotong University Shanghai 200240 China

The sorption of a triazol derivative, 1-(4-chlorophenyl)- 4,4-dimethyl-2-(1H-1,2,4-triazol-1-yl)penten-3.ol with a common name of S3.07D, on fifteen soils and three H_2O_2-treated soils was investigated. The sorption isotherm for each untreated and treated soil was non-linear, and was best fitted to Freundlich sorption equation. Soils containing high amount of clay content or organic matter or both sorbed much higher amounts of the chemical than soils that had low contents of these soil constituents. H_2O_2-treated soils showed considerable sorptive affinity for S3.07D. It was concluded that both organic matter and mineral fraction in natural soils contributed to the sorption of the basic compound. Sorption by the H_2O_2 treated soils increased as suspension pH decreased, but all suspension pHs exceeded the pKa of the compound by more than two units. This implies that organic base protonation can occur on surfaces of soil components, and surface acidity (exchangeable acidity ) is important in sorption process of the organic base rather than suspension pH.

关键词： sorption organic base soil surface acidity

A Resistivity Gradient Piezoelectric FGM Actuator

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Journal of Materials science & technology 2000年第4期16卷 383-386页

作者： S. U.Adikary and Zhongyan MENG (school of Materials science and Engineering, shanghai {3., shanghai 201800, China) Dengren JIN (school of Materials science and Engineering, shanghai Jiaotong {3., shanghai 20003., China) school of Materials science and Engineering Shanghai University Shanghai 201800 China school of Materials science and Engineering Shanghai Jiaotong University Shanghai 200030 China

A resistivity gradient actuator based on lead zirconate titanate ceramics was successfully developed and the bending deflections up to 140 μm were obtained. The actuator material was a matrix of PZT ceramic into which smooth gradient of piezoelectric activity was introduced. The application of an electric field then causes the actuator to bend due to differential strains induced by the piezoelectric effect. The resistivity gradient of the actuator was achieved by doping PZT with suitable donor and acceptor dopants. PZT powder was modified and synthesized by using two stage powder fabrication method. The actuator was fabricated by uniaxial pressing followedby isostatic pressing with two layers of different resistivities.

关键词： PZT FGM

Dislocation Densites of Deformed Steel Sheets Based on Positron Annihilation

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International Journal of Minerals,Metallurgy and Materials 1998年第1期12卷 47-50页

作者： Yonglin Kang Xianjin Wang (Materials science and Engineering school, university of science and technology Beijing, Beijing 100083. China) Materials science and Engineering school University of Science and Technology Beijing Beijing 100083 China

The variation regularity of dislocation densites of some deformed steel sheets under three kinds of strainpaths as uniaxial tension, plane strain and equal biaxial stretching was investigated by means of positron lifetimespectrum and Doppler-broadening techniques. The results show that the increasing rate of dislocation densites isrelated to the plastic strain path. A relationship between the increasing rate of micro-defects, macro-instability andforming limits during the process of steel sheet forming was got based on analyzing the mechanism of dislocationdensity increasing under different stress-strain condihons.

关键词： positron annihilation dislocation steel sheet strain path

New templates of CNN for extracting corners of objects in gray-scale images

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Journal of university of science and technology Beijing 2003年第3期10卷 73-75页

作者： Lequan Min, Ming Lei, and Xisong DongApplied science school, university of science and technology Beijing, Beijing 100083. China Appl. Sci. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

A new cellular neural network (CNN) with nonlinear templates is presented forextracting convex corners of objects in gray-scale images. Application examples showed that the newCNN can even detect convex corner charact... 详细信息

关键词： cellular neural network extract convex comers gray-scale images

Phenomenological Modeling of Warm Compaction and Experimental Verification

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International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 292-295页

作者： Shiju Guo, Tao Lin (Material science and Engineering school, university of science and technology Beijing, Beijing 100083. China) Material science and Engineering school University of Science and Technology Beijing Beijing 100083 China

A phenomenological modeling approach to establishing the warm compaction equation and curves by modifying the regression equation of the room-temperature compaction curve is presented. An enhanced factor of compacting pressure is introduced into the equation in order to reveal the effects of powder/die temperature and filling height of powders on green density. Compaction curves yielded from this equation are consistent with the experimental data of ATOMET grade iron powders. The curves show that the powder/ die temperature should reduce as the filling heights of powders increase and that in some cases warm compaction can not give rise to a higher green density.

关键词： powder metallurgy warm compaction compaction equation Materials