PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2020
·
IF 5.627
Yan Zhang,Xiaoyuan Zhang,Chuangchuang Cao,Jiabiao Zou,Tianyu Li,Jiuzhong Yang,Lili Ye,Yuyang Li
This work reports an experimental and kinetic modeling investigation on the flow reactor pyrolysis of iso -butylbenzene and tert -butylbenzene at 0.04 and 1 atm. Pyrolysis products were detected and identified using synchrotron vacuum ultraviolet photoionization mass spectrometry , and their mole fractions versus heating temperature were measured. High-pressure-limit and pressure-dependent rate constants of unimolecular decomposition reactions of iso -butylbenzene were calculated in this work using the same method as the theoretical calculation investigation on similar reactions of n -butylbenzene, sec -butylbenzene and tert -butylbenzene reported by Belisario-Lara et al. [ J. Phys. Chem. A , 122 (2018) 3980–4001]. Furthermore, a pyrolysis model of four butylbenzene isomers was developed from our previous models of n -butylbenzene and sec -butylbenzene and validated by the present experimental data. Modeling analysis was performed to reveal key pathways in fuel decomposition and polycyclic aromatic hydrocarbon (PAH) formation of iso -butylbenzene and tert -butylbenzene. The dominant decomposition reactions of iso -butylbenzene and tert -butylbenzene under pyrolysis conditions are benzylic C C bond dissociation reactions, while the major products in pyrolysis process are produced by β - scission reactions of primary radical products. Fuel-specific pathways are found to strongly affect the formation of PAHs, especially for indene, naphthalene and phenanthrene. Fuel isomeric effects on the pyrolysis of four butylbenzene isomers were also analyzed with special concerns on the fuel decomposition and PAH formation processes. Different sidechain structures result in different distributions of major products, while different formation pathways and concentrations of precursors lead to different formation tendency of typical PAHs.
研究领域:
化学工程
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燃料化学
✓ 已验证
DOI
高影响因子
Forests
·
2024
·Vol. 15
·期 2
·244
·
IF 2.4
Quanmin Wen,Ruixu Chen,Tian Xu,Dejun Hao
Conifers have evolved sophisticated terpenoid defenses for protection against herbivores and pathogens.Pinus massonianaLamb. is the most widely distributed pioneer afforestation and resin tree species in China, but is seriously harmed by pine wilt disease.Monochamus alternatusis the main vector of pine wilt disease in China. Monoterpenes, sesquiterpenes and diterpenes, the main secondary defensive compounds ofP. massoniana, are catalyzed by different terpene synthases (TPSs), which participate in the important defense pathways against external biotic and abiotic stresses. Here, we aimed to identify the terpene synthases (TPSs) inP. massoniana,responding to the feeding ofM. alternatus, and to characterize the functions and products of the mono-TPSs. We identified six differentially expressed TPS genes in theP. massonianafed upon byM. alternatus, including four mono-TPS and two sesqui-TPS genes. The functions of the four mono-TPSs were verified by analysis of the main product and by-products of these mono-TPSs. (+)-α-Pinene, (−)-α-pinene, and limonene were the major products of TPS (+)-α-pinene, TPS (−)-α-pinene, and TPS limonene, respectively, but TPS (−)-β-pinene only catalyzed a trace amount of (−)-β-pinene in the products. Our findings shed light on the potential relationships between the structure of terpene synthases and their corresponding products.
研究领域:
植物学
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分子生物学
·
生态学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2018
·
IF 5.123
Yinhui Yang,Zhengfeng Chang,Xiaohong Yang,Meiling Qi,Jinliang Wang
Herein we report a propeller-like hexaphenylbenzene-based hydrocarbon material (denoted as BT) as the stationary phase for capillary gas chromatography (GC). The statically-coated BT capillary column showed a high column efficiency of 4340 plates m −1 and weak polarity. Owing to its unique conformation, π-electron toroidal delocalization and intrinsic microporosity , the BT stationary phase exhibited interesting selectivity for aromatic compounds over alkanes. Compared with the graphene (G) column, the BT column showed much prolonged retention and high selectivity for aromatic isomers, especially methylnaphthalenes , dimethylnaphthalenes and phenanthrene/anthracene, mainly because of its propeller-like conformation with rich intercalation effects. Moreover, it exhibited good column repeatability (intra-day, inter-day) and reproducibility (between-column) with RSD values on the retention times less than 0.08% for intra-day, 0.32% for inter-day and 3.8% for between-column, respectively. Also, it showed good potential for determination of minor isomer impurities in real samples. To the best of our knowledge, this work presents the first example of employing an neat aromatic hydrocarbon material as the GC stationary phase with high selectivity for analytes of a wide ranging polarity.
研究领域:
分析化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2016
·
IF 3.926
Xiaohong Yang,Changxia Li,Meiling Qi,Liangti Qu
This work presents the separation performance of graphene-ZIF8 (G-Z) composite material as stationary phase for capillary gas chromatography (GC). The G-Z stationary phase achieved high column efficiency of 5000 plates/m determined by n -dodecane ( k = 1.22) at 120 °C and showed weakly polar nature. Importantly, it exhibited high selectivity and resolving capability for branched alkane isomers and aromatic positional isomers, showing clear advantages over the reported neat graphene and ZIF8. In addition, it attained high resolution for geometric cis -/ trans -isomers. The G-Z column exhibited good column thermal stability up to 300 °C and column repeatability with RSD values of retention times in the range of 0.01–0.19% for intra-day, 0.05–0.88% for inter-day and 0.66–5.6% for between-column, respectively, Moreover, the G-Z column was employed for the determination of minor impurity isomers in real reagent samples, which demonstrates its promising potential in GC applications .
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2020
·
IF 5.627
Yan Zhang,Bowen Mei,Xiaoyuan Zhang,Siyuan Ma,Yuyang Li
This work reports an experimental and kinetic modeling investigation on the laminar flame propagation of three butylbenzene isomers ( n -butylbenzene, iso -butylbenzene and tert -butylbenzene)/air mixtures. The experiments were performed in a high-pressure constant-volume cylindrical combustion vessel at the initial temperature of 423 K, initial pressures of 1–10 atm, and equivalence ratios ( ϕ ) of 0.7–1.5. The laminar burning velocities of butylbenzene/O 2 /He mixtures were also measured at 423 K, 10 atm and ϕ = 1.5 to provide additional experimental data under conditions that the butylbenzene/air experiments are susceptible of cellular instability. Comparison among the laminar burning velocities of butylbenzenes including both the three isomers investigated in this work and sec -butylbenzene investigated in our recent work [Combust. Flame 211 (2020) 18–31] shows remarkable fuel isomeric effects, that is, iso -butylbenzene has the slowest laminar burning velocities, followed by n -butylbenzene and tert -butylbenzene, while sec -butylbenzene has the fastest laminar burning velocities. A kinetic model for butylbenzene combustion was developed to simulate the laminar flame propagation of butylbenzenes. Sensitivity analysis was performed to reveal important reactions in laminar flame propagation of butylbenzenes, including both small species reactions and fuel-specific reactions. Kinetic effects are concluded to result in the different laminar burning velocities of four butylbenzene isomers. Small species reactions control the laminar flame propagation under lean conditions, which results in small differences of laminar burning velocities. Chain termination reactions, especially fuel-specific reactions, have important contributions to inhibit the laminar flame propagation under rich conditions. The structural features of butylbenzene isomers can significantly affect the formation of some crucial radicals such as methyl, cyclopentadienyl and benzyl radicals under rich conditions, which leads to remarkable fuel isomeric effects on their laminar burning velocities, especially at high pressures.
研究领域:
燃烧学
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化学动力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2022
·
IF 4.601
Ziqi Sun,Meiling Qi
This work presents the investigation of a novel CO 2 -based poly(ether-carbonate) copolymer, namely poly(propylene ether-carbonate)diol (PPCD), for gas chromatographic (GC) analyses. The PPCD column exhibited column efficiency of 4000 plates/m determined by naphthalene at 120 ℃ with the retention factor 6.23. Its separation performance was investigated by adopting a wide variety of analytes and isomers, including the isomer mixtures of alkanes, substituted benzene isomers with diverse groups, phenols and anilines, and the mixtures of organic solvents of high volatility, aliphatic amines and N-heterocycles. As a result, the PPCD column displayed distinctly higher resolving capability than the commercial columns described herein and achieved high column inertness towards acidic/basic analytes without involving any deactivation procedure. Additionally, it displayed excellent separation repeatability and reproducibility with the relative standard deviation (RSD) values less than 0.01% for within-day and in the range of 0.26% – 0.36% for between-day and 3.0% – 4.1% for between-column ( n = 4). Further, the PPCD column (30 m) was used to GC–MS analysis of the lemongrass essential oil and resolved more components well than the indicated commercial columns, evidencing its outstanding separation performance for analyses of complex samples. Up to date, the CO 2 -based poly(ether-carbonate) copolymers are not reported in the field of chromatography. This work demonstrates their promising future as a new type of selective and inert stationary phases for practical GC analyses.
研究领域:
化学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Tian-Tian Ma,Cheng Yang,Hai-Long Qian,Piming Ma,Tianxi Liu,Xiu-Ping Yan
Development of novel functional materials for effective isomer separation is of great significance in environmental science, chemical industry, and life science due to the different functions of isomers. However, the similar physicochemical properties of isomers make their separation greatly challenging. Here, we report the fabrication of trifluoromethyl-functionalized 2D covalent organic framework (COF) TpTFMB with 2,2′-bis(trifluoromethyl)benzidine (TFMB) and 1,3,5-triformylphloroglucinol (Tp) for the separation of isomers. TpTFMB was in situ-grown on the inner surface of a capillary for the high-resolution separation of isomers. The introduction of hydroxyl and trifluoromethyl functional groups with uniform distribution in 2D COFs is a powerful tactic to endow TpTFMB with various functions such as hydrogen bonding, dipole interaction, and steric effect. The prepared TpTFMB capillary column enabled the baseline separation of positional isomers such as ethylbenzene and xylene, chlorotoluene, carbon chain isomers such as butylbenzene and ethyl butanoate, and cis–trans isomers 1,3-dichloropropene. The hydrogen-bonding, dipole, and π–π interactions as well as the structure of COF significantly contribute to the isomer separation. This work provides a new strategy for designing functional 2D COFs for the efficient separation of isomers.
研究领域:
材料科学
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化学工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF INSECT SCIENCE
·
2023
·Vol. 23
·期 2
·
IF 2.2
Qiao Heng,Zhu Han,Li Hui,Chen Hongjian,Li Shouyin,Chen Cong,Hao Dejun
Insect intestinal bacteria play an important role in resisting defensive substances of host plants. Pagiophloeus tsushimanus (Coleoptera: Curculionidae) feeds exclusively on camphor trees (Cinnamomum camphora, Laurales: Lauraceae) in China, causing substantial economic and ecological losses. It is unclear how the larvae of P. tsushimanus outcome the main secondary metabolites of C. camphora such as D-camphor, eucalyptol, and linalool. In this study, we isolated terpenoid-degrading bacteria from the gut of P. tsushimanus larvae by using selective culture medium. Maximum likelihood phylogenetic analyses were performed with 16S rDNA sequences to identify the bacteria, and results showed ten strains belonged to four genera, including Pseudomonas, Enterobacter, Serratia, and Corynebacterium. Then, gas chromatography was employed to determine the degradability of D-camphor, eucalyptol, and linalool by the isolated strains, results showed that Z5 strain (i.e., Corynebacterium variabile, Actinomycetales: Corynebacteriaceae), F1 strain (i.e., Pseudomonas aeruginosa, Pseudomonadales: Pseudomonaceae), and A3 strain (i.e., Serratia marcescens, Enterobacterales: Enterobacteriaceae) had the highest degradation rates of D-camphor, linalool, and eucalyptol, respectively. The intestinal bacteria were capable of terpenoid degradation in vitro, which suggested that these gut bacteria associated with P. tsushimanus play an important role in overcoming host plant secondary metabolite defense, thereby facilitating the host specialization of this pest.
研究领域:
昆虫学
·
微生物学
·
植物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
AICHE JOURNAL
·
2023
·Vol. 69
·期 9
·e18102
·
IF 3.7
Yuhan Wang,Chong Shen,Min Qiu,Minjing Shang,Yuanhai Su
In this work, we first solved the partial differential equation of the one-dimensional axial diffusion model in an open-source platform, that is, FEniCS, to explore the influence of the axial dispersion on the reaction yield-to-time profile. Then, we built an automatic platform, which included a photomicroreactor, a continuously controlled pump, a high-power UV-LED light source, an in-line visible-light absorbance analytical unit, and a Raspberry Pi based controlling unit. Moreover, steady-state feeding and sampling functions could be realized in this continuous-flow photochemical platform. The homogeneous photolysis of methylene blue and the photo-Favorskii rearrangement synthesis of ibuprofen as the model reactions were used to validate the robustness of this automatic platform with unsteady-state and steady-state operations, through which kinetic study was carried out using genetic algorithm based symbolic regression, leading to deep understanding on reaction mechanisms and benefits for process optimization.
研究领域:
化学工程
·
人工智能
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）