资源类型

期刊论文 84

年份

2023 10

2022 2

2021 8

2020 6

2019 5

2018 7

2017 2

2016 6

2015 1

2014 1

2013 8

2012 1

2011 5

2010 3

2009 3

2008 6

2007 8

2004 1

展开 ︾

关键词

1T/2H-MoS2 1

ZIF-8 1

三维 1

保险费 1

催化 1

催化膜反应器 1

光催化 1

压降特性;均相模型;分相模型;微通道;流动沸腾 1

原子模拟 1

同质集成;量子阱二极管;可见光互联;发光探测共存现象 1

固体酸碱 1

均相酸碱 1

多孔膜 1

导流风险 1

工程保险 1

抗生素降解 1

有限层 1

机器学习 1

横观各向同性 1

展开 ︾

检索范围:

排序: 展示方式:

Facile synthesis of isoindoline-1,3-diones by palladium-catalyzed carbonylative cyclization of

Mayur V. KHEDKAR, Bhalchandra M. BHANAGE

《化学科学与工程前沿(英文)》 2013年 第7卷 第2期   页码 226-232 doi: 10.1007/s11705-013-1321-x

摘要: A facile method for the carbonylative cyclization of -bromobenzoic acid with primary amine using Pd(OAC) as a metal precursor and 1,1'-bis(diphenylphosphino)ferrocene (dppf) as a ligand has been developed. The effect of various reaction parameters such as ligand, solvent, base, time and temperature on this cyclization was studied. The optimized protocol was used for a wide variety of substituted aryl amines with different steric and electronic properties, affording the corresponding isoindoline-1,3-diones in good to excellent yields under atmospheric pressure of carbon monoxide at 100°C within 10 h using 1,4-diazabicyclo[2.2.2]octane (DABCO) as a base. The reaction system finds attractive alternative to the conventional multistep synthetic process and thus represents an effective utilization of carbonylative protocol for synthesis of valuable chemicals.

关键词: carbonylative cyclization reactions     isoindole-1     3-dinones     homogeneous catalysis     dppf    

Effect of a less permeable stronger soil layer on the stability of non-homogeneous unsaturated slopes

Nabarun DEY, Aniruddha SENGUPTA

《结构与土木工程前沿(英文)》 2020年 第14卷 第6期   页码 1462-1475 doi: 10.1007/s11709-020-0674-8

摘要: Slope failure occurs due to an increase in the saturation level and a subsequent decrease in matric suction in unsaturated soil. This paper presents the results of a series of centrifuge experiments and numerical analyses on a 55° inclined unsaturated sandy slope with less permeable, stronger silty sand layer inclusion within it. It is observed that a less permeable, stronger silty sand layer in an otherwise homogeneous sandy soil slope hinders the infiltration of water. The water content of the slope just above the stronger layer increases significantly, compared to elsewhere. No shear band is found to initiate in a homogeneous sandy soil slope, whereas for a non-homogeneous slope, they initiate just above the less pervious, stronger layer. A discontinuity of the shear zone is also observed for the case of a non-homogeneous soil slope. The factor of safety of a non-homogeneous, unsaturated soil slope decreases because of the less permeable, stronger layer. It decreases significantly if this less permeable, stronger soil layer is located near the toe of the slope.

关键词: non-homogeneous slope     stronger soil layer     factor of safety     centrifuge model test     unsaturated soils    

Control of homogeneous charge compression ignition combustion in a two-cylinder gasoline direct injection

WANG Zhi, WANG Jianxin, SHUAI Shijin, MA Qingjun, TIAN Guohong

《能源前沿(英文)》 2007年 第1卷 第3期   页码 311-315 doi: 10.1007/s11708-007-0045-3

摘要: Homogeneous charge compression ignition (HCCI) has challenges in ignition timing control, combustion rate control, and operating range extension. In this paper, HCCI combustion was studied in a two-cylinder gasoline direct injection (GDI) engine with negative valve overlap (NVO). A two-stage gasoline direct injection strategy combined with negative valve overlap was used to control mixture formation and combustion. The gasoline engine could be operated in HCCI combustion mode at a speed range of 800–2 200 r/min and load, indicated mean effective pressure (IMEP) range of 0.1–0.53 MPa. The engine fuel consumption is below 240 g/(kW

关键词: Homogeneous     control     combustion     consumption     extension    

Liquid discharge plasma for fast biomass liquefaction at mild conditions: The effects of homogeneous

Sen Wang, Shiyun Liu, Danhua Mei, Rusen Zhou, Congcong Jiang, Xianhui Zhang, Zhi Fang, Kostya (Ken) Ostrikov

《化学科学与工程前沿(英文)》 2020年 第14卷 第5期   页码 763-771 doi: 10.1007/s11705-019-1896-y

摘要: Non-thermal plasma exhibits unique advantages in biomass conversion for the sustainable production of higher-value energy carriers. Different homogeneous catalysts are usually required for plasma-enabled biomass liquefaction to achieve time-and energy-efficient conversions. However, the effects of such catalysts on the plasma-assisted liquefaction process and of the plasma on those catalysts have not been thoroughly studied. In this study, an electrical discharge plasma is employed to promote the direct liquefaction of sawdust in a mixture of polyethylene glycol 200 and glycerol. Three commonly used chemicals, sulfuric acid, nitric acid and sodium -toluene sulfate, were selected as catalysts. The effects of the type of catalyst and concentration on the liquefaction yield were examined; further, the roles of the catalysts in the plasma liquefaction process have been discussed. The results showed that the liquefaction yield attains a value of 90% within 5 min when 1% sulfuric acid was employed as the catalyst. Compared with the other catalysts, sulfuric acid presents the highest efficiency for the liquefaction of sawdust. It was observed that hydrogen ions from the catalyst were primarily responsible for the significant thermal effects on the liquefaction system and the generation of large quantities of active species; these effects directly contributed to a higher efficacy of the plasma-enabled liquefaction process.

关键词: discharge plasma     biomass liquefaction     catalyst     homogeneous catalysts    

Recent advances in cycloaddition of CO with epoxides: halogen-free catalysis and mechanistic insights

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 1879-1894 doi: 10.1007/s11705-023-2354-4

摘要: The atom-economical cycloaddition of CO2 with epoxides to synthesize cyclic carbonates is a promising route for valuable utilization of CO2. Halogenide such as alkali metal halides and quaternary ammonium salt have been developed as the efficient catalysts. However, the spilled halogen causes equipment corrosion and affects the product purity. To address these concerns, the halogen-free cycloaddition of CO2 with epoxides has always been desired. In this review, we systematically discussed the halogen-free catalysis for cycloaddition of CO2 with epoxides from the mechanistic insights, aiming to promote the development of efficient halogen-free catalysts. Two types of catalysts, i.e., alternatives of halogen nucleophiles for epoxide activation, and bifunctional catalysts with Lewis acid-base sites for synergistic activation of CO2 and epoxides are summarized and emphasized. Specially, metal oxides as the potential halogen-free catalysts are highlighted due to their flexible acid-base sites for synergistic activation of CO2 and epoxides, facile preparation, and low cost.

关键词: carbon dioxide     halogen-free catalysis     cyclic carbonate     mechanistic insight    

Effects of compression ratio on the combustion characteristics of a homogeneous charge compression ignition

SONG Ruizhi, ZHOU Longbao, LIU Shenghua, LI Wei, HU Tiegang

《能源前沿(英文)》 2007年 第1卷 第4期   页码 463-467 doi: 10.1007/s11708-007-0068-0

摘要: The effects of homogeneous charge compression ignition (HCCI) engine compression ratio on its combustion characteristics were studied experimentally on a modified TY1100 single cylinder engine fueled with dimethyl ether. The resul

关键词: homogeneous     cylinder     combustion     compression     dimethyl    

Application of heterogeneous catalysis to biodiesel synthesis using microalgae oil

《环境科学与工程前沿(英文)》 2021年 第15卷 第5期 doi: 10.1007/s11783-020-1343-9

摘要:

• Microalgae oil application for biodiesel synthesis is discussed.

关键词: Biodiesel     Heterogeneous catalysis     Transesterification     Microalgae oil    

Plasma-catalysis: Is it just a question of scale?

J. Christopher Whitehead

《化学科学与工程前沿(英文)》 2019年 第13卷 第2期   页码 264-273 doi: 10.1007/s11705-019-1794-3

摘要: The issues of describing and understanding the changes in performance that result when a catalyst is placed into plasma are discussed. The different chemical and physical interactions that result and how their combination might produce beneficial results for the plasma-catalytic processing of different gas streams are outlined with particular emphasis being placed on the different range of spatial and temporal scales that must be considered both in experiment and modelling. The focus is on non-thermal plasma where the lack of thermal equilibrium creates a range of temperature scales that must be considered. This contributes in part to a wide range of inhomogeneity in different properties such as species concentrations and electric fields that must be determined experimentally by methods and be incorporated into modelling. It is concluded that plasma-catalysis is best regarded as conventional catalysis perturbed by the presence of a discharge, which modifies its operating conditions, properties and outcomes often in a very localised way. The sometimes used description “plasma-activated catalysis” is an apt one.

关键词: plasma catalysis     plasma-activated catalysis     non-thermal plasma     CO2 conversion    

Frontiers of Catalysis Chemistry and Technology

《化学科学与工程前沿(英文)》 2018年 第12卷 第1期   页码 1-2 doi: 10.1007/s11705-018-1704-0

Scaling up of cluster beam deposition technology for catalysis application

《化学科学与工程前沿(英文)》 2021年 第15卷 第6期   页码 1360-1379 doi: 10.1007/s11705-021-2101-7

摘要: Many research works have demonstrated that the combination of atomically precise cluster deposition and theoretical calculations is able to address fundamental aspects of size-effects, cluster-support interactions, and reaction mechanisms of cluster materials. Although the wet chemistry method has been widely used to synthesize nanoparticles, the gas-phase synthesis and size-selected strategy was the only method to prepare supported metal clusters with precise numbers of atoms for a long time. However, the low throughput of the physical synthesis method has severely constrained its wider adoption for catalysis applications. In this review, we introduce the latest progress on three types of cluster source which have the most promising potential for scale-up, including sputtering gas aggregation source, pulsed microplasma cluster source, and matrix assembly cluster source. While the sputtering gas aggregation source is leading ahead with a production rate of ~20 mg·h–1, the pulsed microplasma source has the smallest physical dimensions which makes it possible to compact multiple such devices into a small volume for multiplied production rate. The matrix assembly source has the shortest development history, but already show an impressive deposition rate of ~10 mg·h–1. At the end of the review, the possible routes for further throughput scale-up are envisaged.

关键词: nanoparticle     cluster     cluster beam deposition     magnetron sputtering     heterogeneous catalysis    

Preface to special issue on “Advanced Materials and Catalysis

《化学科学与工程前沿(英文)》 2021年 第15卷 第6期   页码 1357-1359 doi: 10.1007/s11705-021-2119-x

Reactive adsorption desulfurization over a Ni/ZnO adsorbent prepared by homogeneous precipitation

Aihua KONG, Yanyu WEI, Yonghong LI

《化学科学与工程前沿(英文)》 2013年 第7卷 第2期   页码 170-176 doi: 10.1007/s11705-013-1322-9

摘要: A high-performance Ni/ZnO adsorbent was prepared by homogeneous precipitation using urea hydrolysis and characterized by N adsorption-desorption, X-ray diffraction (XRD), and scanning electron microscope (SEM). The adsorbent was applied to the deep desulfurization of gasoline and showed a high breakthrough sulfur capacity and a remarkably high volume hourly space velocity. The effects of coexisting olefins in gasoline as well as adsorptive conditions on the adsorptive performance were examined. It was found that olefins in gasoline had a slightly inhibiting effect on the desulfurization performance of the adsorbent. The optimum conditions were 673 K, 1.0 Mpa with a volume hourly space velocity of 60 h . Under the optimum conditions, ultralow sulfur gasoline could be produced and the breakthrough sulfur capacity of the adsorbent was 360 mg-s/g-sorb for the model gasoline.

关键词: nickel     reactive adsorption     desulfurization     thiophene    

Shape selective catalysis in methylation of toluene: Development, challenges and perspectives

Jian Zhou, Zhicheng Liu, Yangdong Wang, Dejin Kong, Zaiku Xie

《化学科学与工程前沿(英文)》 2018年 第12卷 第1期   页码 103-112 doi: 10.1007/s11705-017-1671-x

摘要: Toluene methylation with methanol offers an alternative method to produce -xylene by gathering methyl group directly from C1 chemical sources. It supplies a “molecular engineering” process to realize directional conversion of toluene/methanol molecules by selective catalysis in complicated methylation system. In this review, we introduce the synthesis method of -xylene, the development history of methylation catalysts and reaction mechanism, and the effect of reaction condition in -selective technical process. If constructing -xylene as the single target product, the major challenge to develop -selective toluene methylation is to improve the -xylene selectivity without, or as little as possible, losing the fraction of methanol for methylation. To reach higher yield of -xylene and more methanol usage in methylation, zeolite catalyst design should consider improving mass transfer and afterwards covering external acid sites by surface modification to get short “micro-tunnels” with shape selectivity. A solid understanding of mass transfer will benefit realizing the aim of converting more methanol feedstock into -methyl group.

关键词: shape selective catalysis     methylation of toluene    

Preface to special issue on “Engineering Nanostructured Materials for Advanced Energy and Environmental Catalysis

《化学科学与工程前沿(英文)》 2023年 第17卷 第11期   页码 1621-1622 doi: 10.1007/s11705-023-2365-1

摘要: Preface to special issue on “Engineering Nanostructured Materials for Advanced Energy and Environmental Catalysis”

Catalysis of semihydrogenation of acetylene to ethylene: current trends, challenges, and outlook

《化学科学与工程前沿(英文)》 2022年 第16卷 第7期   页码 1031-1059 doi: 10.1007/s11705-021-2113-3

摘要: Ethylene is an important feedstock for various industrial processes, particularly in the polymer industry. Unfortunately, during naphtha cracking to produce ethylene, there are instances of acetylene presence in the product stream, which poisons the Ziegler–Natta polymerization catalysts. Thus, appropriate process modification, optimization, and in particular, catalyst design are essential to ensure the production of highly pure ethylene that is suitable as a feedstock in polymerization reactions. Accordingly, carefully selected process parameters and the application of various catalyst systems have been optimized for this purpose. This review provides a holistic view of the recent reports on the selective hydrogenation of acetylene. Previously published reviews were limited to Pd catalysts. However, effective new metal and non-metal catalysts have been explored for selective acetylene hydrogenation. Updates on this recent progress and more comprehensive computational studies that are now available for the reaction are described herein. In addition to the favored Pd catalysts, other catalyst systems including mono, bimetallic, trimetallic, and ionic catalysts are presented. The specific role(s) that each process parameter plays to achieve high acetylene conversion and ethylene selectivity is discussed. Attempts have been made to elucidate the possible catalyst deactivation mechanisms involved in the reaction. Extensive reports suggest that acetylene adsorption occurs through an active single-site mechanism rather than via dual active sites. An increase in the reaction temperature affords high acetylene conversion and ethylene selectivity to obtain reactant streams free of ethylene. Conflicting findings to this trend have reported the presence of ethylene in the feed stream. This review will serve as a useful resource of condensed information for researchers in the field of acetylene-selective hydrogenation.

关键词: selectivity     hydrogenation     acetylene     ethylene     palladium    

标题 作者 时间 类型 操作

Facile synthesis of isoindoline-1,3-diones by palladium-catalyzed carbonylative cyclization of

Mayur V. KHEDKAR, Bhalchandra M. BHANAGE

期刊论文

Effect of a less permeable stronger soil layer on the stability of non-homogeneous unsaturated slopes

Nabarun DEY, Aniruddha SENGUPTA

期刊论文

Control of homogeneous charge compression ignition combustion in a two-cylinder gasoline direct injection

WANG Zhi, WANG Jianxin, SHUAI Shijin, MA Qingjun, TIAN Guohong

期刊论文

Liquid discharge plasma for fast biomass liquefaction at mild conditions: The effects of homogeneous

Sen Wang, Shiyun Liu, Danhua Mei, Rusen Zhou, Congcong Jiang, Xianhui Zhang, Zhi Fang, Kostya (Ken) Ostrikov

期刊论文

Recent advances in cycloaddition of CO with epoxides: halogen-free catalysis and mechanistic insights

期刊论文

Effects of compression ratio on the combustion characteristics of a homogeneous charge compression ignition

SONG Ruizhi, ZHOU Longbao, LIU Shenghua, LI Wei, HU Tiegang

期刊论文

Application of heterogeneous catalysis to biodiesel synthesis using microalgae oil

期刊论文

Plasma-catalysis: Is it just a question of scale?

J. Christopher Whitehead

期刊论文

Frontiers of Catalysis Chemistry and Technology

期刊论文

Scaling up of cluster beam deposition technology for catalysis application

期刊论文

Preface to special issue on “Advanced Materials and Catalysis

期刊论文

Reactive adsorption desulfurization over a Ni/ZnO adsorbent prepared by homogeneous precipitation

Aihua KONG, Yanyu WEI, Yonghong LI

期刊论文

Shape selective catalysis in methylation of toluene: Development, challenges and perspectives

Jian Zhou, Zhicheng Liu, Yangdong Wang, Dejin Kong, Zaiku Xie

期刊论文

Preface to special issue on “Engineering Nanostructured Materials for Advanced Energy and Environmental Catalysis

期刊论文

Catalysis of semihydrogenation of acetylene to ethylene: current trends, challenges, and outlook

期刊论文