Abstract:The pyrolysis kinetics of charring materials plays an important role in understanding material combustions especially for constructions materials with complex degradation chemistry. Thermogravimetric analysis (TGA) is frequently used to study the heterogeneous kinetics of solid fuels, however, there is no agreed method to determine the pyrolysis scheme and kinetic parameters for charring polymers with multiple components and competing reaction pathways. This study develops a new technique to estimate the possible numbers of species and sub-reactions in pyrolysis by analysing the second derivatives of TG (DDTG) curves. The pyrolysis of a medium density fibreboard (MDF) in nitrogen is studied in detail, and the DDTG curves are used to locate the temperature of peak mass-loss rate for each sub-reactions. Then, based on the TG data under multiple heating rates, the Kissinger's method is used to quickly find the possible range of values of the kinetic parameters (A and E). These ranges are used to accelerate the optimization of the inverse problem using genetic algorithm (GA) for the kinetic and stoichiometric parameters. The proposed method and the kinetic scheme found are shown to match the experimental data and are able to predict accurately results at different heating rate better than the Kissinger's method and faster than the regular GA search alone. The compensation effect and interdependence among kinetic parameters has been shown to weaken as the TG data available increases. Moreover, conducting TG experiment under multiple heating rates is crucial to obtain good kinetic parameters.

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	1. Pyrolysis of Medium Density Fibreboard: Optimized Search for Kinetics Scheme and Parameters via Genetic Algorithm Driven by Kissinger's Method
	Li K,Huang X,Fleischmann C M,Rein G,Ji J
	Security Science and Technology 29 July 2014
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	Abstract:The pyrolysis kinetics of charring materials plays an important role in understanding material combustions especially for constructions materials with complex degradation chemistry. Thermogravimetric analysis (TGA) is frequently used to study the heterogeneous kinetics of solid fuels, however, there is no agreed method to determine the pyrolysis scheme and kinetic parameters for charring polymers with multiple components and competing reaction pathways. This study develops a new technique to estimate the possible numbers of species and sub-reactions in pyrolysis by analysing the second derivatives of TG (DDTG) curves. The pyrolysis of a medium density fibreboard (MDF) in nitrogen is studied in detail, and the DDTG curves are used to locate the temperature of peak mass-loss rate for each sub-reactions. Then, based on the TG data under multiple heating rates, the Kissinger's method is used to quickly find the possible range of values of the kinetic parameters (A and E). These ranges are used to accelerate the optimization of the inverse problem using genetic algorithm (GA) for the kinetic and stoichiometric parameters. The proposed method and the kinetic scheme found are shown to match the experimental data and are able to predict accurately results at different heating rate better than the Kissinger's method and faster than the regular GA search alone. The compensation effect and interdependence among kinetic parameters has been shown to weaken as the TG data available increases. Moreover, conducting TG experiment under multiple heating rates is crucial to obtain good kinetic parameters.
	TO cite this article:Li K,Huang X,Fleischmann C M, et al. Pyrolysis of Medium Density Fibreboard: Optimized Search for Kinetics Scheme and Parameters via Genetic Algorithm Driven by Kissinger's Method[J].


	2. Numerical Simulation of the Effect of Moving Train on Subway Station Fire
	Zhou Dechuang,Chen Juan,Zhang Yuan
	Security Science and Technology 14 May 2014
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	Abstract:The influence of moving train on subway station fire is simulated by Computational Fluid Dynamics in this paper. The characteristics of piston effect produced by one racing train and two trains racing vis-a-vis are studied respectively. On the basis of simulation, a three dimensional smoke velocity and temperature distribution are investigated. Simulation results show that the air velocity field is disturbed and smoke is stretched to further distance along the platform by a moving train. The smoke layer presents a 'S'-shaped distribution when the piston wind is caused by two trains flashing vis-à-vis, indicating that the smoke layer on the subway platform is diffused and it might be harmful for evacuation.
	TO cite this article:Zhou Dechuang,Chen Juan,Zhang Yuan. Numerical Simulation of the Effect of Moving Train on Subway Station Fire[OL].[14 May 2014] http://en.paper.edu.cn/en_releasepaper/content/4597389

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	3. An effective solvothermal reduction method for preparing reduced graphene oxide
	YUAN Bihe,BAO Chenlu,QIAN Xiaodong,WEN Panyue,XING Weiyi,SONG Lei,HU Yuan
	Security Science and Technology 07 January 2014
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	Abstract:In this work, an effective reduction method for graphite oxide (GO) based on solvothermal reaction is developed. The results from X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) indicate that most of the oxygen functional groups in the GO are removed during the solvothermal reduction process. The reduction efficiency of this method is compared with previous reports about solvothermal reduction of GO. This work paves a way for the large-scale production of graphene.
	TO cite this article:YUAN Bihe,BAO Chenlu,QIAN Xiaodong, et al. An effective solvothermal reduction method for preparing reduced graphene oxide[J].


	4. In situ polymerization of functionalized graphene oxide /phosphoramide oligomer nanocomposites flame retardant: Preparation and its enhancements on fire safety of polypropylene
	YU Bin,WANG Xin,QIAN Xiaodong,XING Weiyi,SONG Lei,HU Yuan
	Security Science and Technology 02 January 2014
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	Abstract:In this work, Graphene oxide (GO) was modified by 4, 4 - diamino diphenyl methane (DDM) and then in situ incorporated into phosphoramide oligomer, resulting in the nanocomposite flame retardant (FRs-FGO) containing exfoliated graphene. Subsequently, the ?ame retardant (FRs-FGO) was incorporated into polypropylene (PP) and simultaneously compatilized with PP-grafted maleic anhydride. TEM results showed that the FGO was dispersed more uniformly in PP than the bare graphene oxide (GO), which was due to of strong interfacial interaction and the previous exfoliation of FGO in FRs before blending. The addition of FRs-FGO into PP led to a signi?cant improvement of the thermal stability at elevated temperature with higher char yields. Moreover, the crystallization and ?re safety properties of PP composites were also improved by the incorporation of FRs-FGO, including 11.4 C increase in crystallization temperature, 66.9% reduction in peak heat release rate, 24.4% decrease total heat release, and 73.0% decrease in ?re growth rate index. By contrast, simple blending of GO with FRs exhibited less improvement in fire safety properties than FRs-FGO, as suggested by cone results, resulting from the improved dispersion and thermal stability of FGO sheets. The flame retardant mechanism was due to the shielding effect of FGO and char layers, which could reduce the release of combustible gases and inhibit the mass and heat transfer between gas and condensed phases.
	TO cite this article:YU Bin,WANG Xin,QIAN Xiaodong, et al. In situ polymerization of functionalized graphene oxide /phosphoramide oligomer nanocomposites flame retardant: Preparation and its enhancements on fire safety of polypropylene[OL].[ 2 January 2014] http://en.paper.edu.cn/en_releasepaper/content/4580148


	5. Secure Data Aggregation for Internet of Things
	ZENG Wenlu,DING Yan,LIU Qian,ZHOU Xianwei
	Security Science and Technology 16 August 2012
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	Abstract:Internet of Things has received more and more attention, due to a wide range of potential applications. In this paper, we propose a secure data aggregation framework for the Internet of Things. It is based on fully homomorphic encryption. It is a form of encryption where any specific algebraic operation performed on the plaintext is equivalent to the same algebraic operation performed on the ciphertext.
	TO cite this article:ZENG Wenlu,DING Yan,LIU Qian, et al. Secure Data Aggregation for Internet of Things[OL].[16 August 2012] http://en.paper.edu.cn/en_releasepaper/content/4487052


	6. Synergistic effect of polyhedral oligomeric silsesquioxane on the flame retardancy and thermal degradation of intumescent flame retardant polylactide
	XUAN Shanyong,HU Yuan,SONG Lei,WANG Xin,YANG Hongyu,LU Hongdian
	Security Science and Technology 11 December 2011
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	Abstract:In this study, intumescent flame retardant polylactide/trisilanolisobutyl polyhedral oligomeric silsesquioxane (PLA/TPOSS) composites were prepared via melt blending method. The morphology of the PLA nanocomposites was assessed by transmission electron microscopy (TEM). The flame retardancy of the PLA/TPOSS composites was evaluated by limiting oxygen index (LOI) test and UL-94 test. It was observed that the addition of TPOSS had evident flame retardant effect in comparison to the results obtained from neat PLA. The PLA nanocomposite showed a 69 % reduction of heat release capacity (HRC) when tested in the microscale combustion calorimeter (MCC). Thermalgravimetric analysis (TGA) showed the incorporation of intumescent flame retardant and TPOSS had effectively delayed the thermo-oxidation process of the PLA. The thermal degradation mechanisms of the PLA/TPOSS composites were investigated by thermogravimetric analysis/infrared spectrometry (TG-IR) and direct pyrolysis/mass (DP-MS) analysis.
	TO cite this article:XUAN Shanyong,HU Yuan,SONG Lei, et al. Synergistic effect of polyhedral oligomeric silsesquioxane on the flame retardancy and thermal degradation of intumescent flame retardant polylactide[OL].[11 December 2011] http://en.paper.edu.cn/en_releasepaper/content/4455127


	7. Synergistic effect of POSS on mechanical properties and flammability of intumescent flame retardant polylactide composites
	WANG Xin,XUAN Shanyong,SONG Lei,YANG Hongyu,LU Hongdian,HU Yuan
	Security Science and Technology 30 November 2011
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	Abstract:The intumescent flame retardant polylactide/polyhedral oligomeric silsesquioxane (IFR-PLA/POSS) composites were prepared via a melt blending method. The morphology of the PLA nanocomposites was assessed by transmission electron microscopy (TEM). Dynamic mechanical analysis (DMA) and tensile tests showed that the incorporation of POSS enhanced the mechanical properties of the PLA matrix. The LOI values increased from 20.0% for neat PLA to 40.0% for PLA based on 22.5 wt% intumescent flame retardant and 7.5 wt% POSS, and the latter could pass UL-94 V0 rating. Thermal gravimetric analysis (TGA) showed that the thermal stability of the residual char at the later stages of the thermal degradation was significantly improved.
	TO cite this article:WANG Xin,XUAN Shanyong,SONG Lei, et al. Synergistic effect of POSS on mechanical properties and flammability of intumescent flame retardant polylactide composites[OL].[30 November 2011] http://en.paper.edu.cn/en_releasepaper/content/4452986


	8. De-noising of Damage Signal in Wire Rope Based on Adaptive Lifting Wavelet
	Zhan Weixia,Tan Jiwen,Wen Yan
	Security Science and Technology 01 June 2011
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	Abstract:At the basis of the adaptive lifting wavelet transform, a method was proposed for solving the problem of noise suppression of the wire rope damage signals. A wavelet with damage property was constructed via lifting scheme, that is,the adaptive update-filter and the adaptive predict-filter were designed using the statistics information of the wire rope damage signals. And the compromise algorithm between software-threshold and hard-threshold was used in the threshold processing. The traditional wavelet and the above proposed transform are applied in de-noising of the practical acquisition of wire rope damage signal. The contrast experiments show that the noise elimination with the improved lifting scheme is better than that achieved by traditional wavelet transform. Moreover, this presented scheme retains the effective information in the break signals and greatly improves the design flexibility and the process speed.
	TO cite this article:Zhan Weixia,Tan Jiwen,Wen Yan. De-noising of Damage Signal in Wire Rope Based on Adaptive Lifting Wavelet[OL].[ 1 June 2011] http://en.paper.edu.cn/en_releasepaper/content/4430494


	9. Modeling Window Glass Cracking Behavior Exposed to Radiation by Monte Carlo Method
	LI Liming,XIE Qiyuan,ZHANG Heping
	Security Science and Technology 20 January 2011
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	Abstract:Thermal cracking of window glass has significant influence on the development of compartment fire. The radiative heat transfer is generally an important part for the analysis. In this paper, a program code based on Monte Carlo method has been developed to analyze the transient temperature distribution and time to first crack of window glass facing radiation. The spectral nature of glass has been accounted for. Comparisons between the predictions and experiment results from literature were made. Results show a good agreement, which suggests good applicability of this program.
	TO cite this article:LI Liming,XIE Qiyuan,ZHANG Heping. Modeling Window Glass Cracking Behavior Exposed to Radiation by Monte Carlo Method[OL].[20 January 2011] http://en.paper.edu.cn/en_releasepaper/content/4408106


	10. A KIND OF IMPLEMENT ABOUT MOBILE SIGNATURE SERVICE BASED ON MOBILE TELEPHONE TERMINAL
	Wang Jian,Xu Guoai,Zhang Miao
	Security Science and Technology 24 December 2009
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	Abstract:Mobile signature is a relatively new security authentication mechanism that a kind of special electric signature. It brings a great convenience for people and helps some enterprise save cost, such as bank. By introducing the concept of mobile signature I will analyze the limitation and deficiency of common electronic signature. The implement of mobile signature will also be introduced in this paper. Meanwhile some information, which mainly includes mobile signature service, mobile signature provider and the cryptographic techniques, involved in the implement will be described in detail.
	TO cite this article:Wang Jian,Xu Guoai,Zhang Miao. A KIND OF IMPLEMENT ABOUT MOBILE SIGNATURE SERVICE BASED ON MOBILE TELEPHONE TERMINAL[OL].[24 December 2009] http://en.paper.edu.cn/en_releasepaper/content/38025

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