Wyniki wyszukiwania - BazTech

1

A novel DOPO-g-KH550 modification wood fibers and its effects on the properties of composite phenolic foams

Ma Y., Geng X., Zhang X., Wang C., Chu F.

Polish Journal of Chemical Technology

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2018

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Vol. 20, nr 2

47--53

EN

A novel 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) graft γ-amino propyl triethoxy silane (KH550) was synthesized and introduced on the surface of wood fi ber. Finally DOPO-g-KH550 treated wood fi ber (DKTWF) was used to prepare DKTWF composite phenolic foams (DKTWFCPF). The structures of DOPO-g- KH550 was acknowledged by Fourier transform infrared (FT-IR) and nuclear magnetic resonance (1 H-NMR). The structures of DKTWF were confirmed by FT-IR. Compared with wood fi ber, the diffraction peaks’ position was basically unchanged, but the crystallinity was slightly increased and thermal stability were dramatically improved, T5% and Tmax increased by 21.9° and 36.1° respectively. But the char yield (800°) was slightly reduced. With the dosage of DKWF, there were different degrees of improvement including the mechanical properties, flame retardancy and microstructure of DKTWFCPF. Comprehensive analysis, the interfacial compatibility was signifi cantly improved between DKTWF and phenolic resin, and the suitable content of DKTWF was 4%.

2

Modeling of Ship Collision Risk Index Based on Complex Plane and Its Realization

Xu X., Geng X., Wen Y.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2016

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Vol. 10, no. 2

251--256

EN

Ship collision risk index is the basic and important concept in the domain of ship collision avoidance. In this paper, the advantages and deficiencies of the various calculation methods of ship collision risk index are pointed out. Then the ship collision risk model based on complex plane, which can well make up for the deficiencies of the widely-used evaluation model proposed by Kearon.J and Liu ruru is proposed. On this basis, the calculation method of collision risk index under the encountering situation of multi-ships is constructed, then the three-dimensional image and spatial curve of the risk index are figured out. Finally, single chip microcomputer is used to realize the model. And attaching this single chip microcomputer to ARPA is helpful to the decision-making of the marine navigators.

3

Overhead Line Fault Section Positioning System Based on Wireless Sensor Network

Dong A., Geng X., Yang Y., Su Y., Li M.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 3b

60--61

EN

This paper introduces overhead line fault detection and location system as the core of industrial control computer. The combination of software and hardware, the methods of current rate of change and zero current detection are used, and so the accuracy of short circuit fault detection is improved. The features of ground phase voltage drop and the 5th harmonic current are integrated. Zigbee wireless chips are used to make into independent signal transmission system. The system has been put into operation, running in good condition.

PL

W artykule przedstawiono system detekcji i lokalizacji awarii w sieci napowietrznej do implementacji w komputerze przemysłowym. W metodzie brana jest pod uwagę m. in. wielkość zmian prądu oraz obecność prądu kolejności zerowej, co poprawiło dokładność wykrywania awarii. Zastosowano także bezprzewodowe łącze Zigbee w celu zwiększenia niezależności przesyłu sygnałów w systemie. Badania potwierdziły poprawność działania.

4

Direct Buck-type AC-AC Converters using VSC Metod

Geng X., Tang H.-J., Jin N., Lan J.-Y.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

257--261

EN

The researches on direct AC-AC converters have been an important field. The DC-modulated method, which was used in DC-DC converters before, is used in AC-AC converters to realize a direct AC-AC converting now. The traditional control method regulates the output by adjusting the duty ratio. Its’ core is the PWM technology. In this paper, the variable structure control (VSC) strategy was utilized in Buck-type AC-AC converters. The simulations and experiments proved that the VSC controller was more efficient and faster response.

PL

W artykule zaprezentowano różne typy strategii sterowania wykorzystywane w przekształtnikach AC-AC typu buick. Symulkacje i badania wykazały wyższość sterowników typu VBSC.

5

Preparation of Al Nanoparticles and Their Influence on the Thermal Decomposition of RDX

Hou C., Geng X., An Ch., Wang J., Xu W., Li X.

Central European Journal of Energetic Materials

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2013

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Vol. 10, no. 1

123--133

EN

Aluminum (Al) nanoparticles were prepared by the DC arc plasma method in order to study the influence of Al nanoparticles on the thermal decomposition of cyclotrimethylenetrinitramine (RDX). The Al powder was characterized by TEM, BET, XRD, and LSA, and the thermal decomposition of RDX and RDX/nanometer Al were examined by DSC. Based on the DSC curves, the thermal decomposition parameters of the samples were calculated and compared. The results showed that the particles of Al are homogeneous and fine, and that the surface is smooth. The TEM results showed that the nanoparticles are spherical, with an average diameter of approximately 60 nm. The peak temperature of RDX decomposition decreased by 4.36 K at the heating rates of 5, 10, and 20 K/min after the addition of nano-Al powder, and the activation energy for decomposition decreased by about 11 kJ/mol. Furthermore, the critical explosion temperature was also reduced. These observable changes indicate that Al nanoparticles act as catalysts for the thermal decomposition of RDX.