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Influence of Solvent on Reaction Path to Synthesis of Methyl N-Phenyl Carbamate from Aniline, CO_2 and Methanol 被引量:3
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作者 安华良 张丽丽 +2 位作者 苑保国 赵新强 王延吉 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第5期607-610,共4页
Methyl N-phenyl carbamate(MPC), an important organic chemical, can be synthesized from aniline,CO2 and methanol. Catalyst Cu-Fe/ZrO2-SiO2 was first prepared and its catalytic performance for MPC synthesis was evaluate... Methyl N-phenyl carbamate(MPC), an important organic chemical, can be synthesized from aniline,CO2 and methanol. Catalyst Cu-Fe/ZrO2-SiO2 was first prepared and its catalytic performance for MPC synthesis was evaluated. Then the influence of solvent on the reaction path of MPC synthesis was investigated. It is found that the reaction intermediate is different with acetonitrile or methanol as a solvent. With acetonitrile as a solvent,the synthesis of MPC follows the reaction path with diphenyl urea as the intermediate, while with methanol as a solvent the reaction occurs via the reaction path with dimethyl carbonate as the intermediate. The catalytic mechanism of cooperative catalysis comprising metal sites, Lewis acid sites and Lewis base sites is proposed according to different reaction intermediates. 展开更多
关键词 reaction path methyl N-phenyl carbamate CO2 ANILINE METHANOL Cu-Fe/ZrO2-SiO2 catalyst
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Theoretical Study of Reaction Paths and Transition States on Conversion Methane into C_2 Hydrocarbons Through Plasma 被引量:2
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作者 王保伟 杨恩翠 +1 位作者 许根慧 郝金库 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第1期44-50,共7页
The direct synthesis of C2 hydrocarbons (ethylene, acetylene and ethane) from methane is one of the most important task in C1 chemistry. Higher conversion of methane and selectivity to C2 hydrocarbons can be real-iz... The direct synthesis of C2 hydrocarbons (ethylene, acetylene and ethane) from methane is one of the most important task in C1 chemistry. Higher conversion of methane and selectivity to C2 hydrocarbons can be real-ized through plasma reaction. In order to explore the reaction process and mechanism, the possible reaction paths (1)—(4) were proposed on coupling reaction of methane through plasma and studied theoretically using semi-PM3 method [PM3 is parameterization method of modified neglect of diatomic overlap (MNDO)] including determining the transition state, calculating the activation energy and thermodynamic state functions and analyzing the bond or-der and intrinsic reaction coordinate. The reaction heat results indicate that the reactions (2) and (4) are exothermic, while reactions of (1) and (3) are endothermic. The activation energy results show that activation energy for reac-tions (1) and (2) was much lower than that of reaction paths (3) and (4). Therefore, paths (1) and (2) is the favorable reaction path energetically. More interestingly by comparing the intrinsic reaction coordinated (IRC) of the reaction paths (1) and (2), it is found that the variations of bond lengths in reaction path (1) has a crucial effect on the poten-tial energy, while in reaction path (2), the adjustment of the system geometry also contributes to the whole potential energy of the system. 展开更多
关键词 reaction path transition state METHANE PLASMA PM3
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Thermodynamic study on reaction path of Hg(Ⅱ) with S(Ⅱ) in solution 被引量:1
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作者 柴立元 王庆伟 +3 位作者 王云燕 李青竹 杨志辉 舒余德 《Journal of Central South University》 SCIE EI CAS 2010年第2期289-294,共6页
The mercury sulfidation experiments were conducted in the pH range from 1 to 13. The results show that Hg(II) reacted with equimolar S( II ) has the lowest remained Hg(II ) concentration (9.7 μg/L) at pH 1.0 ... The mercury sulfidation experiments were conducted in the pH range from 1 to 13. The results show that Hg(II) reacted with equimolar S( II ) has the lowest remained Hg(II ) concentration (9.7 μg/L) at pH 1.0 and the highest remained concentration (940.8μg/L) at pH 13.0. Meanwhile, the changes of pH values were monitored exactly, which reveal that solution pH values change when mixing the same pH value solutions of HgCI2 and Na2S. In order to explain the phenomena and determine the reaction paths of Hg(II) reacting with S( II ) in the solution, the concerned thermodynamics was studied. Species of S( II )-H2O system and Hg(II)-H2O system at different pH values were calculated, and then the species distribution diagrams of S(II)-H2O system, Hg( II )-H2O system and Hg( II )-Cl-OH--H20 system were drawn. Combining the experimental data and thermodynamic calculation, the mechanism of Hg(II) reacting with S(II) was deduced. The results indicate that different species of S( II ) and Hg(II) have the diverse reaction paths to form HgS precipitate at different pH values and the standard Gibbs free energies change (△tGm^⊙) of those equations are also calculated, which can provide a guidance for mercury-containing wastewater treatment with Na2S. 展开更多
关键词 mercury species Na2S THERMODYNAMICS reaction path wastewater treatment △tGm^⊙
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A New Reaction Path for the C+NO→CN+O Reaction:Effect of Reagent Rotation on the Stereodynamics on the ~4A″ Potential-Energy Surface
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作者 魏强 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第1期35-38,共4页
The stereodynamics of the C^NO reaction is investigated at O.06eV by means of the quasi-classical trajectory method on a recent ab initio 4^A" potential energy surface (PES). The influences of rotation excitation ... The stereodynamics of the C^NO reaction is investigated at O.06eV by means of the quasi-classical trajectory method on a recent ab initio 4^A" potential energy surface (PES). The influences of rotation excitation (j = 0 -3) on stereodynamics are discussed. The obtained stereodynamical information is compared with the previously reported results on the 2A′ and 2^A" PESs to give a full insight into the chemical stereodynamics of the title reaction. 展开更多
关键词 CNO PES CN+O reaction:Effect of Reagent Rotation on the Stereodynamics on the Potential-Energy Surface A New reaction path for the C+NO
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Kinetic analysis of PODE_(1–3)combustion mechanisms:towards a general framework for reaction pathways
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作者 He Liu Yajing Yang +4 位作者 Yanju Wei Abdullah Baig Yuning Tang Muhammad Shahid Farooq Ning Li 《Energy Storage and Saving》 2025年第2期228-238,共11页
Polyoxymethylene dimethyl ethers(PODEs)have emerged as promising clean alternative fuels for compression-ignition engines.The combustion characteristics of PODE vary with the degree of polymerization,necessitating a d... Polyoxymethylene dimethyl ethers(PODEs)have emerged as promising clean alternative fuels for compression-ignition engines.The combustion characteristics of PODE vary with the degree of polymerization,necessitating a deeper understanding of their kinetic behavior.This study constructed and validated a kinetic mechanism for PODE_(2–3)based on a previously developed detailed kinetic mechanism for PODE_(1).The good performance of the proposed model in reproducing the data indicates the validity of the constructed kinetic mechanism for PODE_(2–3).A general framework for PODE reaction pathways was proposed,with special attention paid to the reaction kinetics of each original reaction.Three source routes of PODE reactivity were elucidated:(1)Route 1:a typical chain branching reaction after hydrogen abstraction from the primary carbon,followed by two oxygenation reactions;(2)Route 2:chain branching reactions in the decomposition of partial hydroperoxyl fuel radicals to carbonyl hydroperoxides;and(3)Route 3:chain branching reactions followed by hydrogen abstraction from secondary carbon,leading to low-polymerization fuel radicals.Routes 1 and 2 are chain-branching reaction pathways common to all PODE molecules;Route 3 is a reaction pathway exclusive to highly polymerized PODE,where low-polymerization fuel radicals in the decomposition products enhance the reactivity by continuing to react with oxygen.In contrast,PODE1 exhibited significantly lower reactivity than the other components because of the absence of Route 3 reaction pathway.The kinetic mechanism of PODE fuel reactivity as a function of the degree of polymerization was elucidated.Our findings are beneficial for the development of more precise computational models to predict the combustion behavior of PODE as an alternative fuel. 展开更多
关键词 Polyoxymethylene dimethyl ethers Kinetic mechanism General framework reaction path
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The Contradictions between the Total-Entropy and the Gibbs Energy When Applied to the Evolving Path and State of Equilibrium of Thermodynamically-Reversible Chemical Reactions
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作者 José C. ĺñiguez 《Journal of High Energy Physics, Gravitation and Cosmology》 2025年第1期120-137,共18页
This paper, an addendum to “Dialectical Thermodynamics’ solution to the conceptual imbroglio that is the reversible path”, this journal, 10, 775-799, was written in response to the requests of several readers to pr... This paper, an addendum to “Dialectical Thermodynamics’ solution to the conceptual imbroglio that is the reversible path”, this journal, 10, 775-799, was written in response to the requests of several readers to provide further evidence of the said “imbroglio”. The evidence here presented relates to the incompatibility existing between the total-entropy and the Gibbs energy prescriptions for the reversible path. The previously published proof of the negentropic nature of the transformation of heat into work is here included to validate out conclusions about the Gibbs energy perspective. 展开更多
关键词 Total-Entropy Gibbs Energy Evolving path EQUILIBRIUM Contradictory Prescriptions for Thermodynamically Reversible Chemical reactions
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Identifying the convergent reaction path from predesigned assembled structures: Dissymmetrical dehalogenation of Br_(2)Py on Ag(111) 被引量:3
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作者 Jinping Hu Zhaofeng Liang +9 位作者 Kongchao Shen Lei Xie Huan Zhang Chaoqin Huang Yaobo Huang Han Huang Jianxin Tang Zheng Jiang Miao Yu Fei Song 《Nano Research》 SCIE EI CSCD 2021年第12期4704-4713,共10页
On-surface Ullmann coupling has been intensely utilized for the tailor-made fabrication of conjugated frameworks towards molecular electronics, however, reaction mechanisms are still limitedly understood. Herein, we p... On-surface Ullmann coupling has been intensely utilized for the tailor-made fabrication of conjugated frameworks towards molecular electronics, however, reaction mechanisms are still limitedly understood. Herein, we provide a comprehensive elucidation of the surface Ullmann coupling of 2,7-dibromopyrene (Br2Py) on Ag(111) by scanning tunnelling microscopy (STM), X-ray photoelectron spectroscopy (XPS) and density function theory (DFT), and reveal that the Ullmann reaction path is unique regardless of predesigned assembled structures. By manipulating deposition conditions, diverse assembled architectures have been constructed for Br2Py on Ag(111), including the ladder phase, parallel arrangement, hexagonal patterns from monomers or Kagome lattices based on organometallic (OM) dimers. Intriguingly, stepwise annealing leads to an identical reaction diagram for the surface Ullmann coupling from individual assembled structures convergent into the brick-wall-pattern OM dimers first, which is deemed to be a stable phase, and then into elongated OM chains in order and eventually long-range polymers with direct C-C coupling. While the reaction mechanism is demonstrated to be dominated by the metal coordinated and halogen bonding motifs, interestingly, it has also been revealed that surface adatoms and dissociated Br atoms play a crucial role in coupling reactions. In contrast to previous reports demonstrating the manipulation of Ullmann reactions by preassembled strategy, herein, weak intermolecular interaction in assembled nanostructures is immediately suppressed by strong covalent bonding during reactions. Importantly, our report proposes essential insights on fundamental understanding of surface Ullmann coupling towards high-yield surface synthesis. 展开更多
关键词 self-assembly Ullmann coupling organometallic intermediates reaction path scanning tunneling microscopy
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Reaction path synthesis methodology for waste minimization 被引量:2
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作者 HU Shanying LI Mingheng +2 位作者 LI Yourun SHEN Jingzhu LIU Zheng 《Science China Chemistry》 SCIE EI CAS 2004年第3期206-213,共8页
It is a key step for reducing waste generation in chemical processes to design op-timal reaction paths. In this paper, methods of waste minimization for reaction path synthesis problems are proposed to realize eco-ind... It is a key step for reducing waste generation in chemical processes to design op-timal reaction paths. In this paper, methods of waste minimization for reaction path synthesis problems are proposed to realize eco-industrial production mode with minimum waste emission. A new conception of simple stoichiometric reaction is presented for reaction path synthesis problem. All simple stoichiometric reactions can be obtained by mathematical transformation for atom matrix of a reaction system. Based on the conception, a two-tier optimization method for complex reaction path synthesis problems is addressed. The first step is to determine the eco-nomic optimal overall reactions, and the second step to decompose each overall reaction into several sub-reactions and find out the best thermodynamic feasible reaction path. Further, a method of reaction path synthesis with waste closed-cycle is proposed based on simple stoichiometric reactions for achieving zero waste emission to poly-generation problem of multi-products. Case studies show that the proposed methods can efficiently solve practical re-action path synthesis problems. 展开更多
关键词 reaction path synthesis waste minimization simple stoichiometric reaction atom matrix closed-cycle.
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Density Functional Theory and MP2 Calculations of the Transition States and Reaction Paths on Coupling Reaction of Methane through Plasma
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作者 杨恩翠 赵小军 +1 位作者 田鹏 郝金库 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2004年第5期430-433,共4页
The two possible reaction paths of producing ethane on coupling reaction of methane through plasma were theoretically investigated by B3LYP and MP2 methods with 6-311G* respectively and further compared with the previ... The two possible reaction paths of producing ethane on coupling reaction of methane through plasma were theoretically investigated by B3LYP and MP2 methods with 6-311G* respectively and further compared with the previous results calculated from B3LYP/6-31G*. The new investigated results consistently confirmed the previous conclusion. And the influences of the calculation methods and basis sets on the calculated results were also dis-cussed. 展开更多
关键词 density functional theory MP2 transition state reaction path METHANE PLASMA
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Oxidation Evolution and Activity Origin of N-Doped Carbon in the Oxygen Reduction Reaction
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作者 Jiaqi Wu Chuanqi Cheng +2 位作者 Shanshan Lu Bin Zhang Yanmei Shi 《Transactions of Tianjin University》 EI CAS 2024年第4期369-379,共11页
N-doped carbon materials,with their applications as electrocatalysts for the oxygen reduction reaction(ORR),have been extensively studied.However,a negletcted fact is that the operating potential of the ORR is higher ... N-doped carbon materials,with their applications as electrocatalysts for the oxygen reduction reaction(ORR),have been extensively studied.However,a negletcted fact is that the operating potential of the ORR is higher than the theoretical oxida-tion potential of carbon,possibly leading to the oxidation of carbon materials.Consequently,the infl uence of the structural oxidation evolution on ORR performance and the real active sites are not clear.In this study,we discover a two-step oxida-tion process of N-doped carbon during the ORR.The fi rst oxidation process is caused by the applied potential and bubbling oxygen during the ORR,leading to the oxidative dissolution of N and the formation of abundant oxygen-containing functional groups.This oxidation process also converts the reaction path from the four-electron(4e)ORR to the two-electron(2e)ORR.Subsequently,the enhanced 2e ORR generates oxidative H_(2)O_(2),which initiates the second stage of oxidation to some newly formed oxygen-containing functional groups,such as quinones to dicarboxyls,further diversifying the oxygen-containing functional groups and making carboxyl groups as the dominant species.We also reveal the synergistic eff ect of multiple oxygen-containing functional groups by providing additional opportunities to access active sites with optimized adsorption of OOH*,thus leading to high effi ciency and durability in electrocatalytic H_(2)O_(2) production. 展开更多
关键词 Oxygen reduction reaction N-doped carbon reaction path Structural evolution Oxidation in reduction
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Bifurcation of reaction paths on a type of potentialenergy surfaces
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作者 廖结楼 王宏利 辛厚文 《Chinese Science Bulletin》 SCIE EI CAS 1995年第7期566-570,共5页
Bifurcation of potential energy surfaces(PES) along the reaction paths (RPS) has stimu-lated great interest of some chemists. It was first discovered by Dewar et al. intheir study on the decyclization of cyclobutene, ... Bifurcation of potential energy surfaces(PES) along the reaction paths (RPS) has stimu-lated great interest of some chemists. It was first discovered by Dewar et al. intheir study on the decyclization of cyclobutene, and that the Wood-Hoffmann rule lost 展开更多
关键词 BIFURCATION reaction path ENERGY surface.
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Theoretical study of dynamical properties on reaction path in molecular internal coordinates
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作者 李宗和 徐红 +2 位作者 许贤忠 曹晓燕 刘若庄 《Science China Chemistry》 SCIE EI CAS 1999年第6期605-611,共7页
The dynamical properties on reaction path (IRC) in internal coordinates have been obtained, which includeωK(frequencies orthogonal to IRC), LK(vibrational modes),BKF(coupling constants between the IRC and vibrations ... The dynamical properties on reaction path (IRC) in internal coordinates have been obtained, which includeωK(frequencies orthogonal to IRC), LK(vibrational modes),BKF(coupling constants between the IRC and vibrations orthogonal to it), BKL, (coupling constants between every two vibrations orthogonal to IRC). A set of theory of reaction path in molecular intemal coordinates has been also constructed. The dynamical properties, includingωK,BKF,BKL of the reaction H1O2H3+H4→H1O2+H3H4 have been calculated, which explicitly explain the interaction, changing trend and contribution of each chemical bond (including bond angle) in the reaction. 展开更多
关键词 MOLECULAR INTERNAL COORDINATES reaction path.
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On the Reaction Path Hamiltonian
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作者 孙家钟 李泽生 《Science China Chemistry》 SCIE EI CAS 1994年第2期129-140,共12页
A vector-fiber bundle structure of the reaction path Hamiltonian, which has been introduced by Miller, Handy and Adams, is explored with respect to molecular vibrations orthogonal to the reaction path. The symmetry of... A vector-fiber bundle structure of the reaction path Hamiltonian, which has been introduced by Miller, Handy and Adams, is explored with respect to molecular vibrations orthogonal to the reaction path. The symmetry of the fiber bundle is characterized by the real orthogonal group O(3N- 7) for the dynamical system with N atoms. Under the action of group O(3N- 7). the kinetic energy of the reaction path Hamiltonian is left invariant. Furthermore , the invariant behaviour of the Hamiltonian vector fields is investigated. 展开更多
关键词 reaction path HAMILTONIAN vector-fiber BUNDLE Hamlltonian VECTOR fields.
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纳米或超细WC-Co粉体制备过程强化研究进展
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作者 潘锋 尚慧俊 +1 位作者 黎亨利 杜占 《中国粉体技术》 CAS 2025年第1期1-10,共10页
【目的】总结纳米或超细碳化钨钴(WC-Co)粉体制备过程的研究,解决WC-Co做为热喷涂原料对机械零件的磨损和腐蚀的影响。【研究现状】总结纳米或超细WC-Co制备过程强化、反应路径,以及Co对还原碳化过程的作用等;其中机械作用力强化包括球... 【目的】总结纳米或超细碳化钨钴(WC-Co)粉体制备过程的研究,解决WC-Co做为热喷涂原料对机械零件的磨损和腐蚀的影响。【研究现状】总结纳米或超细WC-Co制备过程强化、反应路径,以及Co对还原碳化过程的作用等;其中机械作用力强化包括球磨强度的影响、氧化钨原料的影响、反应温度的影响,原子或分子水平强化包括气相化学合成、喷雾转化,气相碳质强化反应过程包括烃类物质、一氧化碳;纳米或超细WC-Co制备过程反应路径包括还原过程、碳化过程;对还原碳化过程的作用包括Co对氧化钨还原碳化过程具有催化作用、Co影响WC-Co产物粒径、Co含量增加降低碳化温度、Co促进气态碳源析碳等。【结论与展望】提出WC-Co粉体制备反应路径方面,应深入揭示制备反应路径,应进一步分析缺碳相η物相在制备过程中的作用,对W、Co、C扩散的影响机制;认为模拟分析反应过程中还原碳化气与固体原料之间的热量、质量传递过程,可为制备过程进一步优化调控和反应器放大设计奠定理论基础;同时WC-Co粉体热喷涂性能方面,用于机械件的喷涂处理时,应测试涂层的抗磨损和腐蚀性能,反馈调控优化和制备过程。 展开更多
关键词 硬质合金涂层 纳米或超细WC-Co 技术进展 反应路径
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氨气/甲烷层流预混火焰NO生成特性研究 被引量:1
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作者 纪飞宇 李青 +2 位作者 马柳昊 杜建国 王宇 《工程热物理学报》 北大核心 2025年第5期1719-1727,共9页
采用氨(NH_(3))/碳氢燃料掺混燃烧被视为实现双碳目标的有效途径,但其存在氮氧化物(NO_(x))排放较高的问题。而目前针对氨燃料燃烧中NO的生成情况,尚缺乏相关基础火焰实验数据。因此,本文搭建了基于McKenna NH_(3)/CH_(4)层流预混火焰... 采用氨(NH_(3))/碳氢燃料掺混燃烧被视为实现双碳目标的有效途径,但其存在氮氧化物(NO_(x))排放较高的问题。而目前针对氨燃料燃烧中NO的生成情况,尚缺乏相关基础火焰实验数据。因此,本文搭建了基于McKenna NH_(3)/CH_(4)层流预混火焰的NO免标定、保湿、定量测量实验平台,研究了当量比及掺氨比对NO生成特性的影响,并分析了不同工况下影响NO生成的关键反应路径。研究结果表明:低当量比时,NO浓度沿轴向方向先急剧上升,在约2 mm位置处达到峰值而后保持不变,高当量比时,NO排放浓度随轴向高度的增加先上升后下降;NO浓度随掺氨比的增加呈现先上升后下降的趋势,随当量比的增加逐渐下降且浓度峰值逐渐向低掺氨比移动;与实验测量结果相比,Okafor机理在低当量比时不同掺氨比下的预测均较为准确,高当量比时有待进一步研究。 展开更多
关键词 氨气/甲烷 层流预混燃烧 一氧化氮 激光吸收光谱技术 反应路径分析
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水蒸气添加对氨/甲烷火焰中NO生成特性的影响研究
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作者 李锦涛 李青 +2 位作者 纪飞宇 马柳昊 王宇 《燃烧科学与技术》 北大核心 2025年第4期466-478,共13页
本文以水蒸气掺混对氨/甲烷层流预混火焰中NO生成的影响为研究目标,对比了不同掺氨比、当量比下掺水对NO生成特性的影响规律,并进行了NO生成敏感性以及路径分析,以明晰相关作用机制.研究结果表明:纯甲烷和甲烷掺氨火焰(后简称为含氨火焰... 本文以水蒸气掺混对氨/甲烷层流预混火焰中NO生成的影响为研究目标,对比了不同掺氨比、当量比下掺水对NO生成特性的影响规律,并进行了NO生成敏感性以及路径分析,以明晰相关作用机制.研究结果表明:纯甲烷和甲烷掺氨火焰(后简称为含氨火焰)中NO峰值浓度随着掺水比例的增大逐渐下降,且NO下降速率随着掺水比例的增大而提高;低当量比时,纯甲烷火焰中NO随掺水比的相对下降幅度远高于含氨火焰(高出2~4倍),表明掺水策略对纯甲烷火焰NO控制的有效性远高于含氨火焰.高当量比时纯甲烷火焰掺水后NO下降幅度略高于含氨火焰(高20%~110%).水掺混对氨和甲烷火焰中NO影响的主要贡献是热稀释效应,而化学效应影响占比较小.值得注意的是,纯甲烷与含氨火焰的NO生成机制显著不同,纯甲烷火焰中掺水主要通过降低火焰温度抑制热力型NO生成,在含氨火焰中则是通过抑制HNO生成以及促进NO被NH2还原的方式来使NO降低.本文相关结论可对氨气燃烧NO控制策略的优化选择提供了一定的理论依据. 展开更多
关键词 氨气/甲烷 层流预混火焰 掺水 NO生成特性 反应路径分析
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烧结烟气中CO与NO气相反应数值模拟 被引量:1
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作者 李杰 赵跃 +3 位作者 赵欣锋 张纹郗 杨爱民 张遵乾 《中国冶金》 北大核心 2025年第2期102-113,共12页
在烧结过程中产生的烧结烟气含有大量NO以及CO,烟气中的各个组分在热力学与动力学条件合适的情况下,能够互相反应并放出热量。为了研究烧结烟气在不同条件下发生化学反应的过程中CO与NO质量分数的变化规律,使用了CHEMKIN软件中的完全搅... 在烧结过程中产生的烧结烟气含有大量NO以及CO,烟气中的各个组分在热力学与动力学条件合适的情况下,能够互相反应并放出热量。为了研究烧结烟气在不同条件下发生化学反应的过程中CO与NO质量分数的变化规律,使用了CHEMKIN软件中的完全搅拌反应器(PSR)模块对反应过程进行建模,并针对CO和NO质量分数以及系统温度3个指标进行了化学反应路径以及敏感性的分析。研究结果表明,在反应过程中,温度、氧气质量分数以及水蒸气质量分数在反应过程中都会对CO和NO质量分数产生影响,其中温度对降低NO和CO质量分数的影响最大,水蒸气其次,氧气质量分数影响最小。 展开更多
关键词 烧结烟气 CHEMKIN 反应路径 完全搅拌反应器 敏感性分析
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预混氨/二甲醚化学反应机理优化及动力学数值模拟分析
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作者 尹莹 卞迁 +3 位作者 魏代君 乔彦宇 董全 程强 《燃烧科学与技术》 北大核心 2025年第4期415-426,共12页
为了解决氨作为内燃机燃料所存在的点火困难和火焰传播速度慢问题,目前普遍采用高活性燃料作为助燃剂来提高氨(NH3)燃料的点火和燃烧的稳定性.二甲醚(DME)具有燃烧性能好、能量密度高等优点,因此本研究选择二甲醚作为高活性燃料与氨混合... 为了解决氨作为内燃机燃料所存在的点火困难和火焰传播速度慢问题,目前普遍采用高活性燃料作为助燃剂来提高氨(NH3)燃料的点火和燃烧的稳定性.二甲醚(DME)具有燃烧性能好、能量密度高等优点,因此本研究选择二甲醚作为高活性燃料与氨混合,从而为零碳燃料的稳定燃烧提供理论基础.本文在氨和二甲醚单独燃烧化学反应动力学的基础上,构建了氨-二甲醚混合燃料燃烧化学反应动力学模型.基于CHEMKIN PRO平台,采用现有的氨和二甲醚机理作为基础骨架机理,引进C-N反应机理以及氨和二甲醚、氨基和二甲醚产生的自由基间的交叉反应,在此基础上通过Cantera结合遗传算法来调整部分较敏感反应所对应的指前因子,对机理进行改进和优化.最终所得机理包含177种组分和1151个基元反应.该机理能够很好地拟合宽范围工况下实验的滞燃期结果,对未来氨/二甲醚应用在发动机的工作环境提供了基础机理. 展开更多
关键词 氨-二甲醚 机理优化 敏感性分析 反应路径分析 滞燃期
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银催化剂纳米结构对其催化性能的影响研究
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作者 马静艳 《现代工程科技》 2025年第16期85-88,共4页
为利用银在纳米尺度下丰富的结构构型与独特的催化性能,发挥其在调控电子结构、反应路径及吸附活性方面的显著优势,系统梳理了银催化剂纳米结构的常见形貌类型及其对催化活性的结构影响,重点分析了晶面构型、尺寸效应、高指数面及协同... 为利用银在纳米尺度下丰富的结构构型与独特的催化性能,发挥其在调控电子结构、反应路径及吸附活性方面的显著优势,系统梳理了银催化剂纳米结构的常见形貌类型及其对催化活性的结构影响,重点分析了晶面构型、尺寸效应、高指数面及协同作用对活性位点分布与反应选择性的调节机制。进一步探讨了晶面结构、纳米尺寸等离激元效应及应变调控对电子结构与反应路径的深层调控作用,揭示了银催化剂结构–电子–性能间的内在耦合机制,为银基纳米催化剂的理性设计与多领域应用提供了理论支撑。 展开更多
关键词 银催化剂 纳米结构 电子结构调控 反应路径 催化性能
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PCR技术在食品微生物检测中的应用与优化
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作者 王静 张兴吉 《现代食品》 2025年第15期134-136,共3页
随着食品安全问题的凸显,快速、准确检测食品微生物污染成为保障公众健康的关键。聚合酶链式反应(Polymerase Chain Reaction,PCR)技术因其高灵敏度、高特异性和快速性,在食品微生物检测中展现出显著优势。本文围绕PCR技术类型及其适用... 随着食品安全问题的凸显,快速、准确检测食品微生物污染成为保障公众健康的关键。聚合酶链式反应(Polymerase Chain Reaction,PCR)技术因其高灵敏度、高特异性和快速性,在食品微生物检测中展现出显著优势。本文围绕PCR技术类型及其适用性,分析其在病原菌检测、腐败菌与发酵菌检测、转基因成分检测中的应用,提出切实有效的优化策略,并在此基础上就PCR技术在应用中的常见问题与解决方案进行了简要论述。 展开更多
关键词 食品安全 聚合酶链式反应(PCR) 微生物检测 应用路径
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