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三索面空间结构 1

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整体化工厂制造
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无人机；速度识别；故障检测；混沌 1

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Benzenesulfonic acid-grafted UIO-66 with improved hydrophobicity as a stable Brønsted acid catalyst

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1389-1398 doi: 10.1007/s11705-022-2285-5

摘要： Hydrothermal and catalytic stability of UIO-66 MOFs with defective structures are critical aspects to be considered in their catalytic applications, especially under the conditions involving water, moisture and/or heat. Here, we report a facile strategy to introduce the macromolecular acid group to UIO-66 to improve the stability of the resulting UIO-66−PhSO3H MOF in aqueous phase catalysis. In detail, UIO-66−PhSO3H was obtained by grafting benzenesulfonic acid on the surface of the pristine UIO-66 to introduce the hydrophobicity, as well as the Brønsted acidity, then assessed using catalytic hydrolysis of cyclohexyl acetate (to cyclohexanol) in water. The introduction of hydrophobic molecules to UIO-66 could prevent the material from being attacked by hydroxyl polar molecules effectively, explaining its good structural stability during catalysis. UIO-66−PhSO3H promoted the conversion of cyclohexyl acetate at ca. 87%, and its activity and textural properties were basically intact after the cyclic stability tests. The facile modification strategy can improve the hydrothermal stability of UIO-66 significantly, which can expand its catalytic applications in aqueous systems.

关键词： metal−organic frameworks (MOFs)     UIO-66     hydrolysis of cyclohexyl acetate     hydrophobicity     Brønsted acidity    

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Study on extraction of thiophene from model gasoline with br?nsted acidic ionic liquids

Xiaomeng WANG, Mingjuan HAN, Hui WAN, Cao YANG, Guofeng GUAN

《化学科学与工程前沿（英文）》 2011年 第5卷 第1期   页码 107-112 doi: 10.1007/s11705-010-0539-0

摘要： Br?nsted acidic ionic liquids (ILs), -methylimidazole hydrogen sulfate ([HMIm]HSO ) and -methylpyrrolidone hydrogen sulfate ([HNMP]HSO ), are synthesized and employed as extractants to extract thiophene from model gasoline (thiophene dissolved in -octane). The effect of extraction temperature, extraction time and volume ratio of ILs to model gasoline on desulfurization rates is investigated. Then, the optimal desulfurization conditions are obtained: the ratio of ILs to model gasoline is 1∶1, extraction temperature is 50°C for [HMIm]HSO and 60°C for [HNMP]HSO , extraction time is 60 min. Meanwhile, the desulfurization rate of [HNMP]HSO for model gasoline is 62.8%, which is higher than that of [HMIm]HSO (55.5%) under optimal conditions. The reason is discussed on the basis of the interaction energy between thiophene and ILs at the B3LYP/6-311++ G(d,p) level. Furthermore, the total desulfurization rate of [HNMP]HSO and [HMIm]HSO reaches 96.4% and 94.4%, respectively, by multistage extraction. Finally, the used ILs can be reused by vacuum drying, and their desulfurization rates are not significantly decreased after recycling 7 times in single-stage desulfurization.

关键词： br?nsted ionic liquids     model gasoline     thiophene     extraction     density functional theory    

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Biodiesel production by the transesterification of cottonseed oil by solid acid catalysts

CHEN He, PENG Baoxiang, WANG Dezheng, WANG Jinfu

《化学科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 11-15 doi: 10.1007/s11705-007-0003-y

摘要： Methyl esters (biodiesel) were produced by the transesterification of cottonseed oil with methanol in the presence of solid acids as heterogeneous catalysts. The solid acids were prepared by mounting HSO on TiO · nHO and Zr(OH), respectively, followed by calcining at 823K. TiO-SO and ZrOSO showed high activity for the transesterification. The yield of methyl esters was over 90% under the conditions of 230°C, methanol/oil mole ratio of 12:1, reaction time 8 h and catalyst amount (catalyst/oil) of 2% (w). The solid acid catalysts showed more better adaptability than solid base catalysts when the oil has high acidity. IR spectral analysis of absorbed pyridine on the samples showed that there were Lewis and BrØnsted acid sites on the catalysts.

关键词： BrØnsted     reaction     presence     cottonseed     biodiesel    

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Ionic liquid mediated esterification of alcohol with acetic acid

Beilei ZHOU, Yanxiong FANG, Hao GU, Saidan ZHANG, Baohua HUANG, Kun ZHANG

《化学科学与工程前沿（英文）》 2009年 第3卷 第2期   页码 211-214 doi: 10.1007/s11705-009-0054-3

摘要： Highly efficient esterification of alcohols with acetic acid by using a Br?nsted acidic ionic liquid, i.e., 1-methyl-2-pyrrolidonium hydrogen sulfate ([Hnmp]HSO ), as catalyst has been realized. The turnover numbers (TON) were able to reach up to 11000 and turnover frequency (TOF) was 846. The catalytic system is suitable for the esterification of long chain aliphatic alcohols, benzyl alcohol and cyclohexanol with good yields of esters. The procedure of separating the product and catalyst is simple, and the catalyst could be reused. [Hnmp]HSO had much weaker corrosiveness than H SO . The corrosive rate of H SO was 400 times more than that of [Hnmp]HSO to stainless steel.

关键词： ionic liquid     Br?nsted acid     esterification     catalyst    

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Effects of support acidity on the reaction mechanisms of selective catalytic reduction of NO by CH

Shicheng XU, Junhua LI, Dong YANG, Jiming HAO

《环境科学与工程前沿（英文）》 2009年 第3卷 第2期   页码 186-193 doi: 10.1007/s11783-009-0016-5

摘要： The reaction mechanisms of selective catalytic reduction (SCR) of nitric oxide (NO) by methane (CH ) over solid superacid-based catalysts were proposed and testified by DRIFTS studies on transient reaction as well as by kinetic models. Catalysts derived from different supports would lead to different reaction pathways, and the acidity of solid superacid played an important role in determining the reaction mechanisms and the catalytic activities. Higher ratios of Br?nsted acid sites to Lewis acid sites would lead to stronger oxidation of methane and then could facilitate the step of methane activation. Strong Br?nsted acid sites would not necessarily lead to better catalytic performance, however, since the active surface NO species and the corresponding reaction routes were determined by the overall acidity strength of the support. The reaction routes where NO moiety was engaged as an important intermediate involved moderate oxidation of methane, the rate of which could determine the overall activity. The reaction involving NO moiety was likely to be determined by the step of reduction of NO. Therefore, to enhance the SCR activity of solid superacid catalysts, reactions between appropriate couples of active NO species and activated hydrocarbon intermediates should be realized by modification of the support acidity.

关键词： selective catalytic reduction (SCR)     nitric oxide (NO)     methane     support acidity     Br?nsted acid sites     NOy species    

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G-quadruplex formation of oligonucleotides containing ALS and FTD related GGGGCC repeat

Jasna Brčić,Janez Plavec

《化学科学与工程前沿（英文）》 2016年 第10卷 第2期   页码 222-237 doi: 10.1007/s11705-016-1556-4

摘要： A largely increased number of GGGGCC repeats located in the non-coding region of gene have been identified as the leading cause of two related neurological disorders, familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). We examined G-quadruplex forming ability of GGGGCC-repeat containing oligonucleotides with four guanine tracts chosen as the smallest possible model to form a unimolecular G-quadruplex. These oligonucleotides are readily to folded into G-quadruplexes in the presence of K ions. However, the formation of multiple structures makes structural analysis challenging and time consuming. We observed that flanking sequences on 5'- and 3'-ends as well as mutations of loop residues have a profound effect on folding. Sequence d[(G C ) G ] was chosen for further scrutiny and optimization of nuclear magnetic resonance (NMR) spectroscopic properties with dG to 8Br-dG substitutions at specific positions in the sequence under different folding conditions. Expectedly, folding into desired predominant topology is facilitated when substituted residue adopted a conformation in the naturally-occurring structure. Single dG to 8Br-dG substitution at position 21 and fine tuning of folding conditions facilitate folding of d[(G C ) GG GG] into (mostly) a single G-quadruplex, and thus enable determination of its high-resolution structure by high-field NMR.

关键词： G-quadruplex     GGGGCC     NMR     ALS/FTD     polymorphism    

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中国大跨度高速铁路桥梁技术的发展与前景

秦顺全, 高宗余

《工程（英文）》 2017年 第3卷 第6期   页码 787-794 doi: 10.1016/j.eng.2017.11.001

摘要：

中国高速铁路发展迅速，建设了大量跨越大江大河和深山峡谷的大跨度桥梁，已经建成的高铁桥梁最大跨度为630 m，正在建设中的沪通长江大桥和五峰山长江大桥跨度达1092 m。为了解决大跨度桥梁载重量大、结构刚度要求高带来的技术难题，开发了系列多功能合建桥梁建造技术，开展了三索面三主桁、斜主桁、板- 桁架组合、钢- 混凝土组合等新型结构的创新与实践，对高性能材料研发和桥梁结构整体化制造及架设技术进行了探索。

关键词： 高速铁路     大跨度桥梁     多功能组合桥梁     高性能材料     三索面空间结构     整体化工厂制造<br />    

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基于最大密度的小型无人机电机速度估计与故障检测 Research Articles

Jefferson S. SOUZA1,Moises C. BEZERRIL1,Mateus A. SILVA1,Frank C. VERAS2,Abel LIMA-FILHO3,Jorge Gabriel RAMOS4,Alisson V. BRITO1

《信息与电子工程前沿（英文）》 2021年 第22卷 第7期   页码 1002-1009 doi: 10.1631/FITEE.2000149

摘要： 介绍了基于混沌的最大密度信号分析技术在无刷直流电机分析中的应用。利用了从电流信号最大密度估计得出的相关系数。通过实验实现了无刷电机在试验台上的速度估计以及在小型无人机上的故障检测。实验结果表明，在97.8%的案例中可估计电机速度，在82.75%的分析案例中可检测故障。

关键词： 无人机；速度识别；故障检测；混沌    

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标题 作者 时间 类型 操作

Benzenesulfonic acid-grafted UIO-66 with improved hydrophobicity as a stable Brønsted acid catalyst

期刊论文

Study on extraction of thiophene from model gasoline with br?nsted acidic ionic liquids

Xiaomeng WANG, Mingjuan HAN, Hui WAN, Cao YANG, Guofeng GUAN

期刊论文

Biodiesel production by the transesterification of cottonseed oil by solid acid catalysts

CHEN He, PENG Baoxiang, WANG Dezheng, WANG Jinfu

期刊论文

Ionic liquid mediated esterification of alcohol with acetic acid

Beilei ZHOU, Yanxiong FANG, Hao GU, Saidan ZHANG, Baohua HUANG, Kun ZHANG

期刊论文

Effects of support acidity on the reaction mechanisms of selective catalytic reduction of NO by CH

Shicheng XU, Junhua LI, Dong YANG, Jiming HAO

期刊论文

G-quadruplex formation of oligonucleotides containing ALS and FTD related GGGGCC repeat

Jasna Brčić,Janez Plavec

期刊论文

中国大跨度高速铁路桥梁技术的发展与前景

秦顺全, 高宗余

期刊论文

基于最大密度的小型无人机电机速度估计与故障检测

Jefferson S. SOUZA1,Moises C. BEZERRIL1,Mateus A. SILVA1,Frank C. VERAS2,Abel LIMA-FILHO3,Jorge Gabriel RAMOS4,Alisson V. BRITO1

期刊论文