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Cui C.,China Shipbuilding Industry Corporation
High Performance Polymers | Year: 2015

Polyimides (PIs) are widely applied in the fields of aerospace, membrane, and electronic industries. However, with the fast-growing application, the degradation of polymer has become a serious problem people are confronted with. In this work, a series of novel degradable PIs were prepared from diamine 4,6-bis(4-aminophenoxy)pyrimidine with various commercially available aromatic dianhydrides by a conventional two-stage method. The resulting PIs could degrade fast under methylamine medium in N,N-dimethylacetamide, and the degradation mechanism was speculated by analyzing the degradation products. Compared with the traditional method, a facile and effective method for PI degradation was provided. The results suggested that incorporating 4,6-diphenoxypyrimidine structure into polymer chains may grow up to be a new method for polymer degradation. © The Author(s) 2014.

Zhou C.,China Shipbuilding Industry Corporation
Binggong Xuebao/Acta Armamentarii | Year: 2015

The shock-resistant capability of marine equipment and systems is an important factor in determining the vitality of ship in wartime. An accurate torpedo launcher impact finite element analysis model is established based on triple torpedo launcher modal test and the finite element modeling technology. The shock-resistant capability of triple torpedo launcher is simulated and examined by means of a dynamic design analysis method (DDAM) used for examining the shock-resistant capability of marine equipment and GJB1060 launcher shock input spectrum. The simulation results show that the shock response Von-Mises stress of torpedo launcher occurs mainly in X and Y directions, and the max shock response Von-Mises stress occurs in X direction. The max Von-Mises stress in X direction is less than the yield strength of material. The shock-resistant capability of torpedo launcher in X, Y and Z directions is according with the ship anti-shock specifications. © 2015, China Ordnance Society. All right reserved.

Zeng M.,Xian Jiaotong University | Tang L.H.,Xian Jiaotong University | Tang L.H.,China Shipbuilding Industry Corporation | Lin M.,Xian Jiaotong University | Wang Q.W.,Xian Jiaotong University
Applied Thermal Engineering | Year: 2010

A comparative study of effects of attack angle, length of vortex generator, height of vortex generator, fin material, fin thickness, fin pitch and tube pitch on fin performance of vortex-generator fin-and-tube heat exchanger is conducted by numerical method. The parameters of vortex-generator fin-and-tube heat exchangers are optimized by the Taguchi method. Eighteen kinds of models are made by compounding levels on each factor, and the heat transfer and flow characteristics of each model are analyzed. The results show that these six factors (fin pitch, longitudinal tube pitch, transverse tube pitch, length of vortex generator, height of vortex generator, and attack angle of vortex generator) have great influences on the JF-factor. The fin material and fin thickness have trifling effects on the JF-factor. The two optimal conditions (A1B3C3D2E1F2G1H3 and A2B2C2D3E1F2G1H3) are acquired, and the reproducibility of the results is verified by two analytical results. © 2010 Elsevier Ltd. All rights reserved.

Zhang Y.,Central South University | Liu Y.,Central South University | Ji X.,Central South University | Banks C.E.,Central South University | And 2 more authors.
Chemical Communications | Year: 2011

Sea cucumber-like hydroxyapatite fabricated with the aid of a Nafion N-117 cation exchange membrane was applied to the detection of lead(ii) and cadmium(ii) in ultra-trace concentration levels. The proposed HAp-modified carbon paste electrode has significantly lower linear ranges and exhibits a larger sensitivity than those reported previously. © 2011 The Royal Society of Chemistry.

Wang D.,Zhengzhou University | Wang H.,China Shipbuilding Industry Corporation | Liu L.,Peoples Bank of China
Swarm and Evolutionary Computation | Year: 2016

Effective environment exploration in unknown environment is precondition of constructing the environment map and carrying out other tasks for multi-robot system. Due to its excellent performance, particle swarm optimization (PSO) has been widely used in multi-robot exploration field. To deal with its drawback - easily trapped in local optima, Darwinian PSO (DPSO) optimization is proposed by Tillett et al. [1] with the natural selection function and first used in real world robot exploration by Couceiro et al. [2], forming the robotic DPSO (RDPSO). To increase the algorithm performance and control its convergence rate, fractional calculus is used to replace inertia component in RDPSO for its "memory" ability and forming the fractional order RDPSO (FORDPSO). This paper presents a formal analysis of RDPSO and studies the influence of the coefficients on FORDPSO algorithm. To satisfy the requirement of dynamically changing robots' behaviors during the exploration, fuzzy inferring system is designed to achieve better control coefficients. Experiment results obtained in two complex simulated environments illustrate that biological and sociological inspiration is effective to meet the challenges of multi-robot system application in unknown environment exploration, and the exploration effect of the fuzzy adaptive FORDPSO is better than that of the fixed coefficient FORDPSO. Furthermore, the performance of FORDPSO with different neighborhood topologies are studied and compared with other six PSO variations. All the results demonstrate the effect of the FORDPSO on the multi-robot environment exploration. © 2015 Elsevier B.V. All rights reserved.

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