Advances in Materials Science

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Authors: Hong Zhu Zhang, Lai Gui Wang, Mei Sheng Feng
Abstract: In order to research the geogrid technology to improve the tailings dam stability,the paper introduces the mechanism of the geogrid reinforcing tailings dam and the simulation principle of the geogrids unit.It also introduces a calculation example.It uses the FLAC3D software to make a comparative study for the dam stability when geogrids reinforcing dam or no reinforcement. The result shows that: The X displacement value is reduced after reinforcement,but far from reinforced area X displacement is not change.It shows that the reinforcement effection appears at the reinforcement surrounding area.There is a little change about the landslide face after reinforced,which is more closer near early dam from the beach top. The safety coefficient rise from 1.69 to 2.37.The reinforcement effection is in good working order. The paper can provide some reference and instruction to the tailings dam safety.
Authors: Yu Jia Tie, Wei Yang, Hao Yu Tan
Abstract: Precise dynamic model of spacecraft is essential for the space missions, to be completed successfully. Nevertheless, the independent orbit or attitude dynamic models can not meet high precision tasks. This paper developed a 6-DOF relative coupling dynamic model based upon the nonlinear relative motion dynamics equations and attitude kinematics equations described by MRP. Nonlinear synchronization control law was designed for the coupled nonlinear dynamic model, whose close-loop system was proved to be global asymptotic stable by Lyapunov direct method. Finallly, the simulation results illustrate that the nonlinear adaptive synchronization control algorithm can robustly drive the orbit and attitude errors to converge to zero.
Authors: Yi Min Li, Yang Cai
Abstract: A novel Adaptive Fuzzy Sliding Mode Control (AFSMC) methodology is proposed in this paper based on the integration of Sliding Mode Control (SMC) and Adaptive Fuzzy Control (AFC).To get rid of the chattering and the bound of uncertainty, an adaptive fuzzy logic system design method introduced for the switching gain is proposed. The main advantage of our proposed methodology is that the nonlinear systems are unknown and no knowledge of the bounds of parameters, uncertainties and external disturbance are not required in advance.the design for the switching gain which will relax the requirement for the bound of uncertainty can ensure stability. The simulation results illustrate the effectiveness of the method.
Authors: Chang Shun Wang, Ying Bing Zhou, Wei Gang Pan, Yao Zhen Han, Feng Yu Zhou
Abstract: Marine diesel engine electronic governor is an important component of the main engine monitoring system, the major problems of current electronics governor is that there is generally more obvious variable gain self-tuning in the main marine, as well as large changes in operating environment, vary speed requirements under different sea conditions. Traditional control methods can’t be satisfactory. To get a better effect, auto disturbance rejection control techniques is introduced. In this paper, the question of ADRC parameter setting is solved combined with genetic algorithm.
Authors: Shi Qiang Cui, Shou Zhi Pu, Wei Jun Liu
Abstract: A new photochromic compound 1-(2,5-dimethyl-3-thienyl)-2-(2-methyl-5-(1-formyl-2- methoxyl-5-phenyl)-3-thienyl)perfluorocyclopentene (1a) was synthesized, its photochromic properties were examined, the result indicated that the color of the compound 1a changed from colorless to a purple one upon irradiation with 297 nm UV light, a new absorption maxima were observed at 542 and 557 nm in hexane and PMMA film, respectively. The new photochromic compound also exhibited remarkable optical recording character.
Authors: Ming Liu, Gang Liu, Cong Bin Fan, Shi Qiang Cui
Abstract: A new photochromic diarylethene compound, 1-[2-methyl-5-(3-chlorophenyl) -3-thienyl]-2-[2-methyl-5-(2-pyridine)-3-thienyl]perfluorocyclopentene(1a) was synthesized. its photochromism was investigated. It exhibited good photochromism and functioned as an effective fluorescent photoswitch both in solution and in PMMA films.
Authors: Bao Song Wang, Xue Qiang Lv, Xin Long Ma, Hong Wei Wang
Abstract: YCbCr color space is widely used in skin detection. An improved method is brought up in this paper: a method based on irregular polygon area boundary constraint on YCbCr color space. Experiments shows that this method get more accurate distribution of skin color in YCbCr color space and lower the false detection rate while keeps the precision rate. In consideration of that the value of pix on image is not the real pix in real life, an improved reverse Gamma correction is brought up for solve a problem in reverse Gamma correction. Experiment result shows that improved reverse Gamma correction is better than none improved reverse Gamma correction.
Authors: Zhi Peng Tong, Shou Zhi Pu, Shi Qiang Cui
Abstract: A photochromic diarylethene bearing a six-membered aryl unit 1-[(2,5-dimethyl-3-thienyl)]-2-[2-methy-4-(3,5-difluorophenyl)-phenyl]perfluoroyclopentene (1a) was synthesized and its photochromic and fluorescent properties were also investigated in detail. The results showed that this compound exhibited reversible photochromism, changing from colorless to red after irradiation with UV light, in which absorption maxima were observed at 521 and 536nm in hexane and PMMA film, respectively. The fluorescence intensity decreased along with the photochromism upon irradiation with 297 nm light in hexane.
Authors: Chun Hong Zheng, Shou Zhi Pu, Cong Bin Fan, Wei Jun Liu
Abstract: A new red diarylethene compound, 1,2-bis[2-n-hexyl-5-hydroxymethyl -3-thienyl]-perfluorocyclopentene (1o), was synthesized and its photochemic properties and fluorescence were studied. Specifically, photochromism in solution and in poly-methylmethacrylate (PMMA) amorphous films were investigated. The results showed that it exhibited good photochromism in both solution and PMMA amorphous film under photoirradiation. In addition, the compound exhibited relatively strong fluorescence that can be useful for the design of the fluorescence molecule switch.

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