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Influence of Calcium Sulfate State and Fineness of Cement on Hydration of Portland Cements Using Electrical Measurement

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Journal of wuhan university of {2.(Materials science) 2006年第4期21卷 141-145页

作者：魏小胜 Department of Civil engineering Huazhong University of Science and Technology Wuhan 430074 China

The influence of calcium sulfate state and fineness of cement on hydration of Portland cement was studied using electrical resistivity measurement. The bulk resistivity curve of the paste from the abnormal cement mainly with hemihydrate had a characteristic abnormal peak and rapid increase in early period. The resistivity measurement technique can be used to discriminate abnormal setting. For normal cement with gypsum, the increase in fineness of the Portland cement decreases the minimum resistivhy due to a higher ionic concentration and increases the 2. hour resistivity due to a reduction in macroscopic pore size. The setting time, compressive strength, pore structure of pastes made from different cements were carried out to compare the influence of water to cement ratio, calcium sulfate state and fineness. It is found that the electrical and mechanical properties are strongly affected by the initial porosity, the presence of hemihydrate or gypsum, and the fineness of cement.

关键词： false setting electrical resistivity fineness hydration

A new approach based on PSO algorithm to find good computational encoding sequences

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Progress in Natural science:Materials International 2007年第6期17卷 712-716页

作者： Cui Guangzhao1, Niu Yunyun1, Wang Yanfeng1, Zhang Xuncai2.and Pan Linqiang2.1. School of Electrical and Electronic engineering, Zhengzhou university of Light Industry, Zhengzhou 450002.{2. 2. Research Institute of Biomolecular Computer, huazhong university of science and technology, wuhan 43.074,{2.) [a]School of Electrical and Electronic engineering Zhengzhou University of Light Industry Zhengzhou China [b]Research Institute of Biomolecular Computer Huazhong University of Scienc and Technology Wuhan China

Computational encoding DNA sequence design is one of the most important steps in molecular computation. A lot of research work has been done to design reliable sequence library. A revised method based on the support system developed by Tanaka et al. is proposed here with different criteria to construct fitness function. Then we adapt particle swarm optimization (PSO) algorithm to our encoding problem. By using the new algorithm, a set of sequences with good quality is generated. The result also shows that our PSO-based approach could rapidly converge at the minimum level for an output of the simulation model. The celerity of the algorithm fits our requirements.

关键词： DNA computing computational encoding DNA sequences PSO algorithm fitness function

Neural Nets:Another Paradigm for Decision Support

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Journal of Systems engineering and Electronics 1995年第2期6卷 2-8页

作者： Feng Shan (Dept. of ACE, huazhong university of science and technology, wuhan 43.074,{2.) Dept. of ACE Huazhong University of Science and Technology Wuhan 430074 China

The paper presents an important aspect of Neural Nets application, i. e., their usefulness for decision support. The essential feature of the neural net approach to decision making is that it is a black-box approach, which means one does not try to model the underlying processes, but only looks for a tuning of the parameters of the neural net such that the black-box mimics the sensible behavior. Through the existing widespread applications in industry, business and science, the paper emphasizes their common property as a paradigm for decision support.

关键词： Neural network Neural-net controller Decision support Industrial applications.

Electrophoretic Coating of Hydroxyapatite on Pyrolytic Carbon Using Glycol as Dispersion Medium

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Journal of wuhan university of {2.(Materials science) 2008年第3期23卷 293-297页

作者：高林 College of Life science and technology Huazhong University of Science and Technology College of Chemistry and Environmental engineering Yangtze UniversityJingzhou 434023China

Hydroxyapatite （HA） coatings on pyrolytic carbon were produced via electrophoretic deposition （EPD） using glycol and ethanol as dispersion medium respectively. The effect of the solubility of HA in the dispersion medium on crack occurrence and adherence of the coating was investigated by means of scanning electronic microscope （SEM） and atomic absorption spectrometer （AAS）. The results show that the solubility of HA in glycol is higher than that in ethanol. The usage of glycol as a dispersion medium can reduce the possibility of crack formation and enhance the adhesive strength between the coating and the carbon substrate. The green coatings can be sintered under vacuum at 1 000 ℃ whether the coatings are obtained using ethanol or glycol as dispersion medium. No HA decomposition was observed up to 1 000 ℃ by vacuum sintering by X-ray diffraction （XRD） analysis.

关键词： hydroxyapatite electrophoretic deposition coatings dispersion medium glycol

Sufficient and necessary conditions for Lyapunov stability of Lorenz system and their application

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science china(Information sciences) 2010年第8期53卷 1574-1583页

作者： LUO Qi 1 , LIAO XiaoXin 2.& ZENG ZhiGang 2.1 College of Information and Control, Nanjing university of Information science and {2., Nanjing 2.0044, china 2.Department of Control science and engineering, huazhong university of science and technology, Image Processing and Intelligent Control Key Laboratory of Education Ministry of china, wuhan 43.074, china 1. College of Information and Control Nanjing University of Information Science and Technology Nanjing 210044 China2. Department of Control Science and Engineering Huazhong University of Science and Technology Image Processing and Intelligent Control Key Laboratory of Education Ministry of China Wuhan 430074 China

The sufficient and necessary conditions for Lyapunov stability of the zero equilibrium point of Lorenz system are discussed, and some brief criteria are presented for globally exponential stability, globally asymptotical stability and instability. Furthermore, the behavior of the non-zero equilibrium point of Lorenz system is also investigated, and several sufficient and necessary conditions are provided for locally exponential stability and instability. The established theorems in this paper develop and extend the existing achievements on Lyapunov stability of Lorenz system. In conclusion, by applying the obtained results, some less conservative feedback-control laws are derived to guarantee the globally exponential stability of the chaos control of Chen system, Lu¨ system, Yang-Chen system and Yu-Xia Li system.

关键词： Lorenz system Lyapunov stability sufficient and necessary condition bifurcation values globally exponential synchronization

Crystallization and Electrical Properties of (Ba_(0.4)Pb_(0.3))Sr_(0.3)TiO_3 Thin Film by Pulsed laser Deposition

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Journal of wuhan university of {2.(Materials science) 2007年第4期22卷 634-637页

作者：杨卫明 Department of Electronic science and technology Huazhong University of Science and Technology

（Ba0.4Pb0.3）Sr0.3TiO3 thin films were fabricated via pulsed laser deposition （PLD） technique on Pt/TiO2.SiO2.Si substrate. The crystallization of the films was characterized by XRD and FSEM, and the experimental results suggested deposition parameters, especially the deposition temperature was the key factor in forming the perovskite structure. The dielectric properties of the film deposited with optimized parameters were studied by an Agilent 42.4A impedance analyzer at 1 MHz. The dielectric constant was 772. and the loss tangent was 0.006. In addition, the well-shaped hysteresis loop also showed that the film had a well performance in ferroelectric. The saturated polarization P, remnant polarization Pr and coercive field E were about 4.6 μC/cm2. 2.5 μC/cm2.and 2. kV/cm （the coercive voltage is 0.7 V）, respectively. It is suggested the film should be a promising candidate for microwave applications and nonvolatile ferroelectric random access memories （NvFeRAMs）.

关键词： (Ba0.4Pb0.3)Sr0.3TiO3 thin film PLD dielectric properties ferroelectric properties

Further study of sources of the imported cobalt-blue pigment used on Jingdezhen porcelain from late 13 to early 15 centuries

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science china(Technological sciences) 2008年第3期51卷 249-259页

作者： DU Feng1 & SU BaoRu2.1 Institute of Chemistry & Molecular engineering, Qingdao university of {2. & technology, Qingdao 2.6000, china 2.College of Information {2. technology, Qingdao university of {2. & technology, Qingdao 2.6000, china Institute of Chemistry & Molecular engineering Qingdao University of Science & Technology Qingdao 266000 China College of Information science technology Qingdao University of Science & Technology Qingdao 266000 China

Based on the conclusion of modern scientific analysis: the cobalt-blue pigment applied on Jingdezhen official porcelain during Yuan Dynasty and prior to Xuande reign of Ming Dynasty (12.1―142.) contains high iron and low manganese con- tents, and the cobalt during Xuande and after Xuande periods (after 142.) of Ming Dynasty contains high manganese and low iron contents, in combination with the traditional archaeological method, the related historical textual records were in- vestigated and analyzed, the imported cobalt employed on Jingdezhen official porcelain was studied comprehensively, systematically and logically. In fact, 'Su Ma Li Qing' (Samarra-blue) and 'Su Bo Ni Qing' (Sumatra-blue) are definitely different cobalt ores originated in different places, because of their very similar translitera- tions in Chinese, the confusion has appeared in ancient books for more than 400 years, which considered 'Su Ma Li Qing' and 'Su Bo Ni Qing' as the same co- balt-blue pigment. In this article the mistake was corrected, the possible producing places and the approximate eras of the two pigments imported to china and used at Jingdezhen were also suggested.

关键词： imported cobalt-blue pigments employed on official blue-and-white porcelain Yuan Dynasty early Ming Dy- nasty Mn/Fe content ratio Su Ma Li Qing (Samarra-blue) Su Bo Ni Qing (Sumatra-blue) scientific archae- ological research transliteration

Mechanism of Strength Loss of No-bake Phosphate Bonded Sand Mold/Core

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Journal of wuhan university of {2.(Materials science) 2009年第1期24卷 5-8页

作者：张友寿 School of Automobile engineering Wuhan University of Technology School of Mechanical engineering Hubei University of Technology

The strength loss mechanism of the phosphate bonded sand mold/core was studied. The morphology and composition of phosphate membrane on the surface of sands was analyzed with electron probe X-ray microanalyzer. Results show that magnesium causes cracks in cured phosphate membrane and results in the decrease of sand molds/cores strength. However, the addition of magne-sium significantly enhanced hygroscopy resistance of phosphate membrane. In addition, the phosphate binder added with the magnesium modifier has more rapid hardening reaction speed compared that without or with low magnesium binder. It can be concluded that the phosphate binder with the addition of magnesium modifier is favorably used in high humid and cold circumstance.

关键词： phosphate mechanism of strength loss crack hygroscopy resistance

Mechanical Properties of Layered Steel Fiber and Hybrid Fiber Reinforced Concrete

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Journal of wuhan university of {2.(Materials science) 2008年第5期23卷 733-736页

作者：卢哲安 Hubei Key Laboratory of Roadway Bridge and Structure engineering Wuhan University of Technology

To explore a new structure form of fiber reinforced concrete, namely, the layered steel fiber and layered hybrid fiber reinforced concrete （LSFRC and LHFRC）, the mechanical properties of LSFRC and LHFRC, such as compressive strength, tensile strength, flexural strength, fatigue and durability were focused on. The experimental results show that LSFRC and LHFRC can improve the flexural strength of concrete by 2.%-50%. In the aspect of improving the flexural strength of concrete, adulterant rate has more obvious effect than length/diameter ratio. Double logarithmic fatigue equation considered liveability was founded. The impermeability of LHFRC is superior to LSFRC and plain concrete （C）. However, the porosity of LHFRC is lower than LSFRC and C. The shrinkage of LHFRC at every age is obviously lower than C. The antifreeze durability of LHFRC is also better than C.

关键词： layered steel fiber reinforced concrete mechanical properties layer hybrid fiber reinforced concrete