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1

Sound Absorption Properties Of Single-Hole Hollow Polyester Fiber Reinforced Hydrogenated Carboxyl Nitrile Rubber Composites

Jie H., Sheng J., Xiong Y.

Autex Research Journal

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2017

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Vol. 17, no. 3

263--267

EN

A series of single-hole hollow polyester fiber (SHHPF) reinforced hydrogenated carboxyl nitrile rubber (HXNBR) composites were fabricated. In this study, the sound absorption property of the HXNBR/SHHPF composite was tested in an impedance tube, the composite morphology was characterized by scanning electron microscope (SEM), and the tensile mechanical property was measured by strength tester. The results demonstrated that a remarkable change in sound absorption can be observed by increasing the SHHPF content from 0% to 40%. In the composite with 40% SHHPF in 1 mm thickness, the sound absorption coefficient reached 0.671 at 2,500 Hz; the effective bandwidth was 1,800-2,500 Hz for sound absorption coefficient larger than 0.2. But the sound absorption property of the composite deteriorated when the SHHPF content increased to 50% in 1 mm thickness. While with 20% SHHPF proportion, the sound absorption property was improved by increasing the thickness of composites from 1 to 5 mm. Compared with the pure HXNBR of the same thickness, the tensile mechanical property of the composite improved significantly by increasing the SHHPF proportion. As a lightweight composite with excellent sound absorption property, the HXNBR/SHHPF composite has potential practical application value in the fields of engineering.

2

Thermal Expansion of Explosive Molecular Crystals: Anisotropy and Molecular Stacking

Qian W., Zhang C., Xiong Y., Zong H., Zhang W., Shu Y.

Central European Journal of Energetic Materials

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2014

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Vol. 11, no. 1

59--81

EN

Molecular dynamics simulations of three typical explosive crystals, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), 1,1-diamino-2,2- dinitroethene (FOX-7) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), were carried out under NPT ensemble and selected force field. The equilibrium structures at elevated temperatures were obtained, which show that the stacking behaviour of the molecules does not change with temperature. The coefficient of thermal expansion (CTE) values were calculated by linear fitting methods, and the results show that the CTE values are close to the experimental results and are anisotropic. The total energies of the cells expanding along each single crystallographic axis were calculated by the periodic density functional theory method, indicating that the energy change rates are anisotropic, and correlation equations of the energy change vs. CTE values were established. The essence of the anisotropy of the explosive crystal’s thermal expansion was compared and elucidated.

3

DELA: A displacement estimated localization algorithm in the opportunistic communication based wireless sensor network

Deng Y., Yang Y., Xiong Y., Li L.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

112--115

EN

Localization is one of the key problems in our system to collect the data of movement rule of sediment transport by wind for the desertification research. We designed a full covered deployment scheme of base station for providing the basic service of data forwarding and localization first. Then we proposed a displacement estimated localization algorithm (DELA), which can help node to measure its displacement during each movement and then calculate the position. The experiment proved that the DELA is better than the trilateration in this scene.

PL

Przy badaniach pustynnienia i zbieraniu danych w warunkach ruchu osadów porywanych przez wiatr, jednym z kluczowych problemów jest lokalizacja. W opracowaniu, po pierwsze, dla zapewnienia podstawowej obsługi przekazywania danych o przemieszczaniu i lokalizacji, zaprojektowano układ stacji bazowych, całkowicie pokrywający rozmieszczenie węzłów pomiarowych. Następnie, zaproponowano algorytm szacunkowej lokalizacji przemieszczania (DELA), który pomaga węzłowi zmierzyć przemieszczenia podczas jego ruchu i następnie obliczyć pozycję. Badania eksperymentalne wykazują, że DELA daje lepsze wyniki niż trilateracja.

4

Optimal Roadside Gateway Deployment for VANETs

Xiong Y., Ma J., Wang W., Niu J.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 7b

273--275

EN

VANETs allowing the mobile vehicles exchange data with the roadside gateways are being used in various applications such as local electronic advertisement, intelligent transportation system and urban data collection. In this paper, we study the problem of deploying the gateways to provide the desired communication performance while minimizing the deployment cost. The key idea of our solution is to exploit the time-stable vehicular mobility pattern to find the optimal deployment places. We propose a graph model to characterize the observed mobility pattern. Then the gateway deployment problem is transformed into a vertex selection problem in a graph. By reducing it the minimum vertex coverage problem, we show the gateway deployment problem is NP-complete, so a heuristic algorithm MobGDeploy is proposed to search greedily the optimal deployment points. Extensive simulations are carried out to evaluate the performance, and the results show that the proposed algorithm outperforms others.

PL

W artykule analizowano problem rozlokowania wjazdów w celu osiągnięcia pożądanej jakości komunikacji. Przyjęto założenie stabilnej czasowo mobilności pojazdów. Zaproponowano model grafu do opisu mobilności pojazdów. Wykorzystano metodę VANET – vehicular ad hoc network.

5

Fluorescence Analysis as an Effective Method Used in Micro/Trace Explosive Detection

Liu Y., Shu Y., Liu Xue-yong., Xiong Y., Zhong Fa-chun., Sun Y.

Central European Journal of Energetic Materials

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2009

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Vol. 6, nr 3-4

303-311

EN

There are many kinds of explosives, and their detection methods vary. Nitroaromatic compound is one of the composition of the explosives commonly used. The fuorescence will be quenched when they touch the fuorescent conjugated polymers. General methods for explosives detection have been summarized in this paper, in addition the application of novel fuorescence analysis technique in explosives detection has been introduced. Fluorescent conjugated polymer as chemical sensing material for explosive detection has been reviewed in detail, also a novel fuorescent sensing flm self-assembled by fuorescent small molecule pyrene and homogeneous fuoroimmunoassay have been presented briefy. The development of fuorescence analysis used in the area of determining explosives has been prospected.