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STUDIES ON THE KINETICS AND INITIATION MECHANISM OF ACRYLAMIDE POLYMERIZATION USING CERIC/ACETOACETANILIDE SYSTEM AS INITIATOR
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《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第2期103-106,共4页
It is found that acetoacetanilide possesses very high promoting reactivity towards ceric ion in initiating polymerization of vinyl monomer. The kinetics of acrylamide polymerization and the activation energies were st... It is found that acetoacetanilide possesses very high promoting reactivity towards ceric ion in initiating polymerization of vinyl monomer. The kinetics of acrylamide polymerization and the activation energies were studied. The initiation mechanism of ceric/acetoacetanilide is proposed on the basis of experimental results of FT-IR and ESR. 展开更多
关键词 AAA IV AS ESR STUDIES ON THE KINETICS AND INITIATION MECHANISM OF ACRYLAMIDE POLYMERIZATION USING CERIC/ACETOACETANILIDE SYSTEM AS initiator
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A THEORETICAL APPROACH TO NONLINEAR MECHANICAL PROPERTIES OF THE ARTERIAL WALL WITH INITIAL STRESS
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《Chinese Journal of Biomedical Engineering(English Edition)》 1999年第4期77-78,共2页
关键词 SG A THEORETICAL APPROACH TO NONLINEAR mechanical PROPERTIES OF THE ARTERIAL WALL WITH INITIAL STRESS LI
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Dynamic behaviors of rockslides subjected to brittle failure of locked segments 被引量:1
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作者 HU Kai ZHAO Xiao-yan ZHANG Guang-ze 《Journal of Mountain Science》 SCIE CSCD 2023年第2期532-541,共10页
Locked segments are recognized as a critical role that controls the stability of rock slopes but remain an unclear and challenging problem with respect to their role incorporated into the failure mechanism.In order to... Locked segments are recognized as a critical role that controls the stability of rock slopes but remain an unclear and challenging problem with respect to their role incorporated into the failure mechanism.In order to study the effect of the locked segments on the initial failure process of rockslides,thirty-six groups of locked segment specimens with three different lithologies were prepared,direct shear tests were carried out to obtain the accelerations caused by brittle failure of the locked segment specimens.Experiment results showed that the maximum accelerations caused by the brittle failure of locked segment specimens was 2.91 g in the horizontal direction,and 3.18 g in the vertical direction.We took the Wangjiayan rockslide in 2008 Wenchuan earthquake as an example,the critical balance condition of the sliding mass under combined effect of gravity and accelerations induced by brittle failure of locked segment was analyzed,which indicated that the initial failure process of the Wangjiayan rockslides was notably influenced by the existence of the locked segment.The departure acceleration and direction of the Wangjiayan rockslide were proposed.The study results can provide a new insight into the understanding of the initial failure mechanism of rockslides with locked segments. 展开更多
关键词 Rockslides ROCKFALLS Locked segment Direct shear test Initial failure mechanism Sudden departure Brittle failure
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Field observation of debris-flow activities in the initiation area of the Jiangjia Gully, Yunnan Province, China 被引量:3
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作者 YANG Hong-juan ZHANG Shao-jie +3 位作者 HU Kai-heng WEI Fang-qiang WANG Kai LIU Shuang 《Journal of Mountain Science》 SCIE CSCD 2022年第6期1602-1617,共16页
The Jiangjia Gully, which is located in Dongchuan District, Yunnan Province, China, is a watershed prone to debris flows and has long-term recorded data of debris-flow occurrence. However, the initiation mechanism has... The Jiangjia Gully, which is located in Dongchuan District, Yunnan Province, China, is a watershed prone to debris flows and has long-term recorded data of debris-flow occurrence. However, the initiation mechanism has mainly been studied by experiments in this watershed. To further reveal debris-flow formation mechanism in the Jiangjia Gully, debris-flow activities in the initiation zone were observed with hand-held video cameras in the summer of 2016 and 2017. In these two years, six debris-flow events were triggered in Menqian Gully, a major tributary of the Jiangjia Gully, while debrisflow activities in some sub-watersheds of Menqian Gully were recorded with video cameras in four events. The video recording shows that landslides constituted an important source for sediment supply in debris flow. Some landslides directly evolved into debris flows, while the others released sediment into rills and channels, where debris flows were generated for sediment entrainment by water flow. Therefore, debris-flow occurrence in the Jiangjia Gully is influenced both by infiltration-dominated processes and by runoff-dominated processes. In addition, rainfall data from four gauges installed in Menqian Gully were analyzed using mean intensity(I), duration(D), peak 10-minute rainfall(R10min) and antecedent rainfall(AR) up to 15 days prior to peak 10-minute rainfall. It reveals that debris-flow triggering events can be discriminated from nontriggering events either by an I-D threshold or by an R10min-AR threshold. However, false alarms can be greatly reduced if these two kinds of thresholds are used together. Moreover, behaviors including intermittency of debris flow, variance in moisture content and volume among surges, and coalescence of multiple surges by temporary damming were observed, indicating the complexity of debris-flow initiation processes. These findings are expected to enhance our knowledge on debris-flow formation mechanism in regions with similar environmental settings. 展开更多
关键词 Debris flow Field observation Initiation mechanism Rainfall threshold Jiangjia gully
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Numerical Investigation on the Initiation Mechanism of Debris-Flow under Rainfall 被引量:4
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作者 LU Xiaobing YE Tianli +2 位作者 CUI Peng HU Kaiheng CHEN Xiaoqing 《Journal of Mountain Science》 SCIE CSCD 2011年第4期619-628,共10页
Rainfall is an important factor to trigger the debris flow.Numerical simulation on the responses of slopes and the initiation of debris flow under rainfall was processed by using the software FLAC2D based on the soil ... Rainfall is an important factor to trigger the debris flow.Numerical simulation on the responses of slopes and the initiation of debris flow under rainfall was processed by using the software FLAC2D based on the soil parameters in Weijia Gully,Beichuan County,Sichuan Province,China.The effects of the slope angle,rainfall intensity,soil parameters on the developments of the stress and pore pressure and deformation of the slope were studied.It indicates that large displacements of the slope are mainly located near the slope toe.With the increase of the rainfall intensity the stability of the slope decreases and so the debris-flow is easy to occur. 展开更多
关键词 DEBRIS-FLOW Initiation mechanism RAINFALL Numerical simulation
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Role of the reduction site in the fluorinated or sulfated TiO_2 photocatalytic process 被引量:3
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作者 YANG Shi-ying HU Hong +2 位作者 CHEN You-yuan ZHENG Jian-guo CUI Ying-jie 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第10期1239-1244,共6页
In this article, the effects of ZiO2 surface fluorination and sulfation, on the active oxygen species formed at the reduction site in the photocatalytic process, namely O2^*- and H2O2, were investigated from a new pe... In this article, the effects of ZiO2 surface fluorination and sulfation, on the active oxygen species formed at the reduction site in the photocatalytic process, namely O2^*- and H2O2, were investigated from a new perspective. The superoxide radical, (O2^*-), was determined by colorimetry of nitroblue tetrazolium, a prominent O2^*- scavenger. Hydrogen peroxide (H2O2) was estimated by using the iodide-starch method. In the naked TiO2 photocatalysis, O2^*-, though less reactive, was a very important intermediate. When the TiO2 surface was fluorinated, more O2^*- and H2O2 were produced, which indicated that the surface modification could greatly reduce the recombination of photogenerated electrons and holes, thus enhancing the photocatalytic rate. In the sulfated system, photocatalysis proceeded with a more complicated mechanism. These results added support to the view of fluoride-induced enhancement and sulfide's nonappreciable inhibition effect. 展开更多
关键词 TiO2 photocatalysis superoxide radicals surface modification initial mechanism
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Effect of ultrasonic peening treatment on the fatigue behaviors of a magnesium alloy up to very high cycle regime 被引量:2
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作者 Yao Chen Fulin Liu +4 位作者 Chao He Lang Li Chong Wang Yongjie Liu Qingyuan Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2022年第3期659-673,共15页
Ultrasonic fatigue tests are performed on a magnesium alloy with and without ultrasonic peening treatment(UPT).Surface enhancement layer leads to the complete change of crack initiation sites.However,crack initiation ... Ultrasonic fatigue tests are performed on a magnesium alloy with and without ultrasonic peening treatment(UPT).Surface enhancement layer leads to the complete change of crack initiation sites.However,crack initiation mechanism keeps the same and results in a single-faceted morphology at crack initiation site.Microcracks initiate as Mode Ⅱ crack within the original grain,but deflect to Mode I crack outside of the original cracked grain.A threshold SIF value is proposed to evaluate the retarding effect of grain boundary on microcrack propagation.Outside of the original cracked grain,Mode I crack propagation below the threshold ΔK_(σ-th) is responsible for the formation of fine granular area(FGA,a nano-grain layer).Based on the Numerous Cyclic Pressing(NCP) model,it is proposed that crack type should be another necessary condition for the formation of FGA. 展开更多
关键词 Ultrasonic peening treatment Very-high-cycle fatigue Crack initiation mechanism Fine granular area Nanograins.
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Theoretical Study of the Structure,Mechanism of Detonation Initiation and Stability of Transition Metal Carbohydrazide Nitrates 被引量:1
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作者 黄辉胜 张同来 +3 位作者 张胜涛 张建国 吴兴发 徐建华 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第10期1491-1496,共6页
The geometric structure, mechanism of detonation initiation and stability of transition metal carbohydrazide (CHZ) nitrates are investigated via density functional theory. The obtained results show that the Heyd-Scu... The geometric structure, mechanism of detonation initiation and stability of transition metal carbohydrazide (CHZ) nitrates are investigated via density functional theory. The obtained results show that the Heyd-Scuseria-Ernzerhof (HSE) functional yields the most accurate geometry. The initiating reaction of detonation in [Mn(CHZ)3](NO3)2 and [Zn(CHZ)3](NO3)2 is the formation of NO3 radicals. The calculated heat of formation and energy gap predict that the Mn and Zn complexes, which have the half-filled (3d5) and full-filled (3d10) electron configurations for the transition metal ions, respectively are more stable than the Co, Ni and Cu complexes. This indicates that the electron configuration of transition metal ion plays an important role in the stabilities of these energetic complexes. 展开更多
关键词 energetic material density functional theory mechanism of detonation initiation electronic structure STABILITY
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Comparative Study on Debris Flow Initiation in Limestone and Sandstone Spoil
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作者 CHEN Ning-sheng LU Yang +3 位作者 DENG Ming-feng HAN Da-wei ZHOU Hai-bo YANG Cheng-lin 《Journal of Mountain Science》 SCIE CSCD 2013年第2期190-198,共9页
Large spoil tips from reconstruction works as a result of the Wenchuan Earthquake in China are new debris flow hazards to the human society.However,there is a lack of detailed comparative study on debris flow initiati... Large spoil tips from reconstruction works as a result of the Wenchuan Earthquake in China are new debris flow hazards to the human society.However,there is a lack of detailed comparative study on debris flow initiation in different spoil materials.This paper describes a series of tests and analyses on debris flow characteristics(initiation,scale and mechanism) at six sites with limestone and sandstone materials near the Dujiangyan area.Research shows the limestone spoil contains debris flow prone clay content with high concentration of montmorillonite(highly expandable).In addition,limestone spoil is of such a low permeability that water mainly concentrates in the upper surface layer.Those factors make it easy for the increase of pore water pressure,decline of internal friction and conhesion force,leading to the occurence of large debris flows.In contrast,the sandstone spoil is less problematic and causes no major debris flow threats.Based on our research on the mechanism,the"stereometric drainage"method is sucessfully applied to control limestone spoil debris flows. 展开更多
关键词 Debris flows Comparative study Reconstruction spoil Initiation mechanism Mitigation measures
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VINYL RADICAL POLYMERIZATION INITIATED WITH CERIC ION AND ETHYL N, N-DIETHYLDITHIOCARBAMYL ACETATE SYSTEM
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作者 许守军 丘坤元 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1997年第3期254-261,共8页
Acrylamide polymerization initiated with a redox initiation system consisting of eerie ion and ethyl N,N-diethyldithiocarbamyl acetate (EDCA) has been studied. It was found that the polymerization rate equation is in ... Acrylamide polymerization initiated with a redox initiation system consisting of eerie ion and ethyl N,N-diethyldithiocarbamyl acetate (EDCA) has been studied. It was found that the polymerization rate equation is in good agreement with that of a redox initiated polymerization, and the overall activation energy of the polymerization was determined to be 25.2 kJ.mol(-1). Accordingly, the system belongs to a redox initiator. The initiation mechanism was proposed based on the end group analysis using FT-IR, UV spectroscopies. Analysis results revealed that the N, N-diethyldithiocarbamyl radical produced from the redox reaction of EDCA with eerie ion can initiate acrylonitrile (AN) polymerization and form the end group on PAN. The resulting PAN was photopolymerized with butyl acrylate (BE) to form PAN-b-PBA block copolymer. 展开更多
关键词 ceric ion redox initiator N N-diethyldithiocarbamyl-end functional polymer block copolymerization initiation mechanism
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Identification of Forcing Mechanisms of Convective Initiation over Mountains through High-Resolution Numerical Simulations
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作者 Zuohao CAO Huaqing CAI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第10期1104-1105,共2页
Convection and its ensuing severe weather, such as heavy rainfall, hail, tornado, and high wind, have significant im- pacts on our society and economy (e.g., Cao et al., 2004; Fritsch and Carbone, 2004; Verbout et al... Convection and its ensuing severe weather, such as heavy rainfall, hail, tornado, and high wind, have significant im- pacts on our society and economy (e.g., Cao et al., 2004; Fritsch and Carbone, 2004; Verbout et al., 2006; Ashley and Black, 2008; Cao, 2008; Cao and Ma, 2009; Zhang et al., 2014). Due to its localized and transient nature, the initiation of convection or convective initiation remains one of the least understood aspects of convection in the scientific communi- ties, and it is a significant challenge to accurately predict the exact timing and location of convective initiation (e.g., Cai et al., 2006; Wilson and Roberts, 2006; Xue and Martin, 2006; Cao and Zhang, 2016). 展开更多
关键词 OVER QPF Identification of Forcing Mechanisms of Convective Initiation over Mountains through High-Resolution Numerical Simulations
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Experimental analysis for the dynamic initiation mechanism of debris flows
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作者 LI Chi ZHU Wen-hui +3 位作者 LI Lin LU Xiao-bing YAO De Farshad AMINI 《Journal of Mountain Science》 SCIE CSCD 2016年第4期581-592,共12页
Debris flow is one of the major secondary mountain hazards following the earthquake. This study explores the dynamic initiation mechanism of debris flows based on the strength reduction of soils through static and dyn... Debris flow is one of the major secondary mountain hazards following the earthquake. This study explores the dynamic initiation mechanism of debris flows based on the strength reduction of soils through static and dynamic triaxial tests. A series of static and dynamic triaxial tests were conducted on samples in the lab. The samples were prepared according to different grain size distribution, degree of saturation and earthquake magnitudes. The relations of dynamic shear strength, degree of saturation, and number of cycles are summarized through analyzing experimental results. The findings show that the gravelly soil with a wide and continuous gradation has a critical degree of saturation of approximately 87%, above which debris flows will be triggered by rainfall, while the debris flow will be triggered at a critical degree of saturation of about 73% under the effect of rainfall and earthquake(M>6.5). Debris flow initiation is developed in the humidification process, and the earthquake provides energy for triggering debris flows. Debris flows are more likely to be triggered at the relatively low saturation under dynamic loading than under static loading. The resistance of debris flow triggering relies more on internal frication angle than soil cohesion under the effect of rainfall and earthquake. The conclusions provide an experimental analysis method for dynamic initiation mechanism of debris flows. 展开更多
关键词 Mountain hazard Debris flows Initiation mechanism Humidification process Rainfall Earthquake Triaxial test
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Infuence of Liquid Film Characteristics on Hot Cracking Initiation in Al–Cu Alloys at the End of Solidifcation
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作者 Ming Su Xiaoguang Yuan +3 位作者 Chunyu Yue Wentao Zheng Yuxiang Wang Jian Kang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2023年第1期103-117,共15页
In this study,Al–4Cu alloy specimens with spherical grains and liquid flms were obtained by isothermal reheating treatment.The hot cracking of the solidifcation process was determined using a modifed constrained rod ... In this study,Al–4Cu alloy specimens with spherical grains and liquid flms were obtained by isothermal reheating treatment.The hot cracking of the solidifcation process was determined using a modifed constrained rod casting experimental apparatus,and the efect of liquid flm characteristics at the end of solidifcation on hot cracking initiation of Al–4Cu alloys was systematically investigated by combining molecular dynamics simulations and other methods.With the extension of soaking time,the liquid fraction(liquid flm fraction at the end of solidifcation)and grain shape factor increased with higher isothermal reheating temperatures.Additionally,the widened flling channel decreased the hot cracking initiation temperature and the critical hot cracking shrinkage stress was found to increase,thus reducing the hot cracking severity in Al–4Cu alloys.Molecular dynamics simulations revealed that with the extension of soaking time,the composition of the liquid flm changed at diferent isothermal reheating temperatures,but the short-range structure and atomic ordering of the liquid flm remained the same.The activity of the liquid flm increased in equilibrium,leading to a decrease in viscosity and an increase in fuidity,which contributed to the flling behaviour.After isothermal reheating at 640℃for 60 min,the liquid fraction reached the maximum,and the viscosity of the liquid flm was the minimum.In addition,almost no hot cracks were found. 展开更多
关键词 Al-4Cu alloy Liquid flm characteristics Isothermal reheating Molecular dynamics simulation Hot cracking initiation mechanism
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Experimental and DFT study on cerium inclusions in clean steels 被引量:13
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作者 Xiangjun Liu Jichun Yang +3 位作者 Fang Zhang Xiaoyang Fu Hongwei Li Changqiao Yang 《Journal of Rare Earths》 SCIE EI CAS CSCD 2021年第4期477-486,共10页
To provide insights into deforming Ce-O-S-Al inclusions in steels and improving the mechanical properties,the evolution process of such harmful inclusions in clean steels was investigated by thermodynamic calculation,... To provide insights into deforming Ce-O-S-Al inclusions in steels and improving the mechanical properties,the evolution process of such harmful inclusions in clean steels was investigated by thermodynamic calculation,metallographic examination and first-principles calculation in this paper.For the tested IF steel,the thermodynamic analysis results are consistent with the calculated formation enthalpy.After Ce addition,the inclusions are transformed from Al_(2)O_(3)and TiN-Al_(2)TiO_(5)-Al_(2)O_(3)to Ce2O_(3),Ce_(2)O_(2)S,CeAlO_(3),TiN-Al_(2)TiO_(5)-Ce_(2)O_(3)and TiN-Al_(2)TiO_(5)-Ce_(2)O_(2)S composite inclusions,which can be confirmed by metallographic examination.The elastic constants were calculated,and the bulk modulus,Young's modulus,shear modulus and Poisson's ratio were evaluated by the Voigt-Reuss-Hill(VRH)approximation.All inclusions except Ce_(2)O_(3)show apparent brittleness.TiN,Al_(2)O_(3),Al_(2)TiO_(5)and CeAlO_(3)present much higher hardness than iron matrix,while the hardness of Ce2O_(3)or Ce_(2)O_(2)S is close to that of iron matrix.The thermal expansion coefficients of Ce_(2)O_(3)and CeAlO_(3)are close to that of iron matrix,whereas,Ce_(2)O_(2)S inclusion has largely different thermal expansion coefficient from iron matrix and may deteriorate the steel performance at higher temperatures.The relatively small differences between Ce inclusions and iron matrix in terms of hardness,toughness,brittleness,and thermal expansion coefficient can explain the improvement of the mechanical properties of the tested steel. 展开更多
关键词 Thermodynamic analysis Inclusions modification First-principles calculation Thermal expansion coefficient Micro crack initiation mechanism Rare earths
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Initiation Mechanism of Loess Mudflows by Flume Experiments 被引量:5
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作者 Penghui Ma Jianbing Peng +4 位作者 Jianqi Zhuang Xinghua Zhu Cong Liu Yuxiang Cheng Zuopeng Zhang 《Journal of Earth Science》 SCIE CAS CSCD 2022年第5期1166-1178,共13页
The structure of loess is loose,and the shear strength of loess drops sharply after contact with water.Therefore,loess mudflows have become a common geological disaster on the Chinese Loess Plateau.In order to study t... The structure of loess is loose,and the shear strength of loess drops sharply after contact with water.Therefore,loess mudflows have become a common geological disaster on the Chinese Loess Plateau.In order to study the initiation mode and mechanism of loess mudflows,in this study,seven sets of flume experiments were designed by controlling the slope angle and rainfall intensity.The results show that(1)when the slope angle is between 10°and 20°,there are two initiation mechanisms of loess mudflows:mudflow(large scale)and retrogressive toe sliding,and mudflow(small-scale)and retrogressive toe sliding.(2)The main method by which water infiltrates into the soil accumulation is mainly vertical infiltration,which is not affected by the slope angle and the seepage direction of the accumulation soil.(3)The liquefaction of loess is the root cause of loess mudflows.Water infiltrates into the area with an uneven density and a large amount of water accumulates in this area.Thus,the water content of the loess increases and the pore water pressure increases quickly and cannot dissipate in time,so the loess liquefies and the liquefacted area continues to spread and become larger.Thus,loess mudflows(large scale)occur.The increase in pore water pressure was captured in the seven sets of experiments.However,the order of the rising positions in the accumulation were different.This requires us to carry out tracking of the particle displacement inside the soil and the spatial changes in the internal structure of the soil in future research. 展开更多
关键词 flume tests loess mudflow loess liquefaction initiation modes initiation mechanism engineering geology
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Ultrasonic fatigue tests at high temperature on an austenitic steel 被引量:6
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作者 D.Wagner F.J.Cavalieri +1 位作者 C.Bathias N.Ranc 《Propulsion and Power Research》 SCIE 2012年第1期29-35,共7页
The objective of this paper is to study the gigacycle fatigue behavior of an austenitic steel at temperatures of 6001C and 700℃under fully reverse loading(R=-1).Numerical simulation by finite element method(FEM)was u... The objective of this paper is to study the gigacycle fatigue behavior of an austenitic steel at temperatures of 6001C and 700℃under fully reverse loading(R=-1).Numerical simulation by finite element method(FEM)was used to design the specimens and to analyze the effects of the variation in the dynamic Young modulus with temperature from measurements of the ultrasonic resonance frequency.Finally,new stress-life curves for this material are presented for a lifetime range from 10^(5)to 10^(9)cycles at room temperature,600℃and 700℃. 展开更多
关键词 FATIGUE Gigacycle regime High temperature Austenitic steel Finite element method Crack initiation mechanism
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A New View of the Initiation and Propagation in Anionic Polymerization 被引量:2
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作者 Anna Zheng Bo Chen Dihang Hu Yong Guan Dafu Wei Shuzhao Li Dandan Ji 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2013年第3期393-400,共8页
This work confirms the new view of the initiation and propagation mechanism of the anionic polymerization previously proposed, based on the investigation of anionic bulk-polymerization of styrene and α-methyl styrene... This work confirms the new view of the initiation and propagation mechanism of the anionic polymerization previously proposed, based on the investigation of anionic bulk-polymerization of styrene and α-methyl styrene with the help of a self designed microflow device and characterized by GPC and in situ ^7Li NMR. It was found that n-BuLl tended to form the hexameric-aggregated structure and even to form the huge aggregated structure based on the former. These aggregations of initiators could directly initiate the anionic polymerization and form the su-pramolecule aggregations. The supramolecule aggregations inevitably blocked the diffusion of the monomers to the ion-pairs and resulted in a stationary-conversion platform. Then the aggregators were dissociated completely into equal binary-aggregated species, and the polymerization continued again rapidly before the termination. Tetrahy-drofuran (THF) acted as the electron donator, which could push the electron cloud to Li cation and make the aggre- gated ring of the active species rather loosened and facilitated the monomer to insert in. Therefore, a little THF can greatly promote the anionic polymerization. However, further addition of THF might block the channel between the ion-pairs and decrease the propagation rate. It was also found that the aggregated structure of the active species during the anionic polymerization only depends on the initiator aggregations which were formed before the polym-erization. 展开更多
关键词 anionic polymerization initiation mechanism in situ 7^Li NMR ORGANOLITHIUM supramolecular aggre-gator
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Understanding the Initial Decomposition Pathways of the n-Alkane/Nitroalkane Binary Mixture
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作者 Yulei Guan Ying Zhang +1 位作者 Chunhai Yi Bolun Yang 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2013年第8期1087-1094,共8页
Addition of nitroalkanes into n-alkanes can lower the activation barriers of free-radical production and acceler- ate the decomposition of n-alkanes at relatively low temperatures. Four initial decomposition mechanism... Addition of nitroalkanes into n-alkanes can lower the activation barriers of free-radical production and acceler- ate the decomposition of n-alkanes at relatively low temperatures. Four initial decomposition mechanisms of the n-butane/nitroethane binary mixture were proposed for the promoting effect and considered theoretically at the B3LYP, BB1K, BMK, MPW1K, and M06-2X levels with MG3S basis set. Energetics above was compared to high-level CBS-QB3 and G4 calculations. Calculated results confirm the feasibility of the four initial decomposition pathways: (I) the C--NO2 bond rupture of nitroethane to produce ethyl and .NO2, (II) HONO elimination from nitroethane followed by decomposition to .OH and .NO, (1II) rearrangement of nitroethane to ethyl nitrite which further dissociates into CH3CH20. and .NO, and (IV) direct hydrogen-abstraction ofnitroethane with n-butane. 展开更多
关键词 free radical initial decomposition mechanism computational chemistry hydrogen-abstraction bimol-ecular
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