资源类型

期刊论文 266

会议视频 3

年份

2023 28

2022 19

2021 26

2020 18

2019 8

2018 12

2017 12

2016 17

2015 17

2014 17

2013 14

2012 12

2011 13

2010 9

2009 15

2008 13

2007 11

2006 1

2001 1

2000 1

展开 ︾

关键词

勘探开发 2

医学 2

核酸检测 2

肠道菌群 2

高含硫 2

&gamma 1

2-羟基丁酸 1

3-酰基硫代四酸 1

CCK-8 实验 1

CO 1

COVID-19 1

Cas12a 1

DHA 和 sn-2 DHA 1

ITO 1

Kdn 1

MTT 实验 1

Pd局域环境 1

SARS-CoV-2 1

n-Si 1

展开 ︾

检索范围：

排序： 展示方式：

Octane compositions in sulfuric acid catalyzed isobutane/butene alkylation products: experimental and

Lina Liang, Youzhi Liu, Weizhou Jiao, Qiaoling Zhang, Chao Zhang

《化学科学与工程前沿（英文）》 2021年 第15卷 第5期   页码 1229-1242 doi: 10.1007/s11705-020-2030-x

摘要： Octanes in alkylation products obtained from industrial alkylation were studied by batch experiments. More than eight octane isomers were identified and quantified by gas chromatography-mass spectrometry. Based on a classic carbenium ion mechanism, the carbocation transition states in concentrated sulfuric acid catalyzed alkylation were investigated using quantum-chemical simulations and predicted the concentration and octane isomerization products including trimethylpentane and dimethylhexane as well as the formation of heavier compounds that resulted from the oligomerization of octane and butene. The agreement between model calculations and experimental data was quite satisfactory. Calculation results indicated that composition and content of trimethylpentanes in the alkylation products were 2,2,4-trimethylpentane>2,3,3-trimethylpentane>2,3,4-trimethylpentane>2,2,3-trimethylpentane whether the 2-butene or -butene acts as olefin. Heavier compounds in the alkylate were primarily formed by the oligomerization of dimethylhexane with 1-butene. Hopefully, the carbocation transition state models developed in this work will be useful for understanding the product distributions of octane in alkylation products.

关键词： sulfuric acid catalyzed alkylation     carbocation reaction     transition state     octane compositions    

HTML PDF 收藏

Benzene alkylation with long chain olefins catalyzed by ionic liquids: a review

QIAO Congzhen, CAI Yonghong, GUO Quanhui

《化学科学与工程前沿（英文）》 2008年 第2卷 第3期   页码 346-352 doi: 10.1007/s11705-008-0045-9

摘要： The introduction of ionic liquids to alkylation process gives a choice for “green production” in the petrochemical and detergent industry. A lot of papers and patents have been published using chloroaluminate ionic liquid as a novel catalyst for alkylation with high reactivity and easy separation from reactants. These included the acidity, characterization, determination and catalysis technologies in batch and continuous operation mode for different scales. According to published data and several results of pilot alkylation,including the authors’ experience,the prospect of chloroaluminate ionic liquids for commercials was also discussed. It has been pointed out that there still are many difficulties and challenges to be overcome for commercial application of the ionic liquid catalyst.

关键词： different     petrochemical     characterization     introduction     chloroaluminate    

HTML PDF 收藏

Continuous reaction performances of benzene alkylation with long chain olefins catalyzed by ionic liquid

QIAO Congzhen, LI Chengyue

《化学科学与工程前沿（英文）》 2008年 第2卷 第1期   页码 69-73 doi: 10.1007/s11705-008-0014-3

摘要： Based on a compulsive mixing-reacting-separating-recycling small experimental setup,the continuous reaction performances of benzene alkylation with long chain olefins catalyzed by [BMIM]Cl-AlCl ionic liquid were investigated. Three different situations including normal continuous operation mode (reagent materials), sidetrack feeding from different axial positions along the static mixing reactor (reagent materials) and normal continuous alkylation using industrial paraffin and olefins materials were examined. Even under the relatively hypecritical reaction conditions, the single pass conversion of pure 1-dodecene could reach to nearly 100.0%, and the selectivity of 2-phenyl isomer was higher than 37.7%. Although the positions along the reactor for sidetrack feeding were different, the 100.0% single pass conversion of 1-dodecene was also attained before the outlet of the reactor. The refined industrial olefins as raw material could meet with the requirements of continuous alkylation. The influences of impurities such as di-olefins and non-benzene aromatics on the catalytic activity and stability should be studied further.

关键词： stability     different     hypecritical     compulsive mixing-reacting-separating-recycling     non-benzene    

HTML PDF 收藏

Alkylation of benzene with propylene catalyzed by FeCl3-chloropyridine ionic liquid

SUN Xuewen, ZHAO Suoqi, LI Hui

《化学科学与工程前沿（英文）》 2007年 第1卷 第3期   页码 292-295 doi: 10.1007/s11705-007-0053-1

摘要： Alkylation of benzene with propylene was carried out with FeCl3-chloro-butyl-pyridine (FeCl-[bpc]) ionic liquid as catalyst to obtain cumene. Significant improvements in propylene conversion and cumene selectivity under mild reaction conditions were attained by modification of the catalyst with HCl. Under 20ºC, 0.1 MPa, reaction time 5 min, mole ratio of benzene to propylene 10:1 and mass ratio of FeCl-[bpc] to benzene 1:100, conversion of propylene can increase from 83.60% to 100.00% and selectivity of cumene can increase from 90.86% to 98.47%. If reaction is carried out in following two stages, the result will be very good. At the initial stage of the reaction, alkylation is the main reaction and a higher conversion of propylene is obtained at a lower temperature. At the later stage of the reaction, transalkylation is the main reaction and selectivity to cumene can be increased by appropriately raising the reaction temperature.
HTML PDF 收藏

Comparison of prechilling stratification and sulfuric acid scarification on seed germination of

Nan WANG, Jing GAO, Suiqi ZHANG, Feng YAN

《农业科学与工程前沿（英文）》 2017年 第4卷 第2期   页码 220-227 doi: 10.15302/J-FASE-2017146

摘要： In semi-arid regions of the Loess Plateau, water deficiency restricts plant performance. (switchgrass), which is a highly versatile grass, had been introduced to the Plateau as a restoration species. To determine if prechilling stratification (PCS) and sulfuric acid scarification (SAS) can optimize establishment, cvs Pathfinder, Trailblazer and Alamo were tested under different ambient water potentials by measuring germination and root and shoot growth along water potential gradients under laboratory conditions. Both PCS and SAS improved total germination percentage (TGP), with PCS being more beneficial. The effect of PCS and SAS on mean germination time (MGT) weakened gradually with increasing drought stress. Both PCS and SAS showed no obvious effect on promoting root and shoot growth. Both PCS and SAS reduced base water potential requirement for reaching 50% germination of Pathfinder and Trailblazer, with this effect greater for PCS. These results indicate that embryo dormancy may be a major factor limiting germination of under drought conditions. Pathfinder appears to be more suitable for a semi-arid environment, whereas Alamo appears to be unsuitable for drought conditions. Given the large difference between predicted value and measured value, the reliability and applicable scope of linear regression estimated Y needs further investigation, specification and optimization.

关键词： base water potential     data analysis method     embryo growth     germination    

HTML PDF 收藏

Resistance to acid degradation, sorptivity, and setting time of geopolymer mortars

Osama A MOHAMED; Rania AL-KHATTAB; Waddah AL-HAWAT

《结构与土木工程前沿（英文）》 2022年 第16卷 第6期   页码 781-791 doi: 10.1007/s11709-022-0862-9

摘要： Experimental evaluations were conducted to determine the water sorptivity, setting time, and resistance to a highly acidic environment, of mortar with alkali-activated ground granulated blast furnace slag (GBS) binder and also of combinations of fly ash and GBS binders. Binders were activated using mixtures of NaOH and Na2SiO3 solutions. The molarity of NaOH in the mixtures ranged from 10 mol·L−1 to 16 mol·L−1, and the Na2SiO3/NaOH ratio was varied from 1.5 to 2.5. Mortar samples were produced using three binder combinations: 1) GBS as the only binder; 2) blended binder with a slag-to-fly ash ratio of 3:1; and 3) mixed binder with 1:1 ratio of slag to fly ash. Mortar samples were mixed and cured at (22 ± 2) °C till the day of the test. The impact of activator solution alkalinity, activator ratio Na2SiO3/NaOH, GBS content on the rate of water absorption were evaluated. After 7, 28, and 90 d of immersion in a 10% sulfuric acid solution, the resistance of a geopolymer matrix to degradation was assessed by measuring the change in sample weight. The influence of solution alkalinity and relative fly ash content on setting times was investigated. Alkali-activated mortar with a slag-to-fly ash ratio of 3:1 had the least sorptivity compared to the two other binder combinations, at each curing age, and for mortars made with each of the NaOH alkaline activator concentrations. Mortar sorptivity decreased with age and sodium hydroxide concentrations, suggesting the production of geopolymerization products. No reduction in weight of sample occurred after immersion in the strong acid H2SO4 solution for three months, regardless of binder combination. This was due to the synthesis of hydration and geopolymerization products in the presence of curing water, which outweighed the degradation of the geopolymer matrix caused by sulfuric acid.

关键词： alkali-activated materials     fly ash     sorptivity     durability of concrete     sodium hydroxide     sodium silicates     reduction in CO2 emissions     sulfuric acid    

HTML PDF 收藏

Visbreaking of heavy petroleum oil catalyzed by SO/ZrO solid super-acid doped with Ni or Sn

JING Ping, LI Qingbiao, HAN Mei, SUN Daohua, JIA Lishan, FANG Weiping

《化学科学与工程前沿（英文）》 2008年 第2卷 第2期   页码 186-190 doi: 10.1007/s11705-008-0035-y

摘要： SO/ZrO solid super-acid catalysts (SZ) doped with Ni or Sn (Ni/SZ, Sn/SZ) were prepared for catalytic visbreaking of heavy petroleum oil from Shengli oil field. The visbreaking reactions were carried out at 240°C and 3–4 MPa for 24 h using a heavy petroleum oil to catalyst mass ratio of 100 : 0.05. The effect of water content on viscosity of heavy petroleum oil was also investigated. Both catalysts can promote thermolysis of heavy petroleum oil and the viscosity was reduced from 0.319 Pa·s to 0.135 Pa·s for Ni/SZ and 0.163 Pa·s for (Sn/SZ) with visbreaking rates of 57.7% and 48.9%, respectively. After visbreaking, the saturated hydrocarbon content increased while aromatics, resin, asphaltene, sulfur and nitrogen content decreased. The presence of water was disadvantageous to visbreaking of heavy petroleum oil.

关键词： thermolysis     Shengli     asphaltene     SO/ZrO     presence    

HTML PDF 收藏

绿色化的磷复肥生产集成工艺

冯怡生

《中国工程科学》 1999年 第1卷 第1期   页码 58-62

摘要：

磷复肥生产排放的磷石膏废渣堆存占地，污染环境，已成为亟待解决的难题。利用磷石膏制硫酸与水泥，可消除污染，实现硫资源的良性循环，使经济效益、社会效益和环境效益有机统一，促进了磷复肥工业的可持续发展。

关键词： 磷复肥     磷石膏     硫酸     水泥    

HTML PDF 收藏

One-pot three-component Mannich reaction catalyzed by sucrose char sulfonic acid

Qiong XU, Zhigao YANG, Dulin YIN, Jihui WANG

《化学科学与工程前沿（英文）》 2009年 第3卷 第2期   页码 201-205 doi: 10.1007/s11705-009-0052-5

摘要： Sucrose char sulfonic acid efficiently catalyzed the one-pot three-component Mannich reaction of ketones, aromatic aldehydes and amines in ethanol to afford the corresponding -amino carbonyl compounds in good to excellent yields. A series of heteroaromatic -amino carbonyl compounds can be obtained when using 2-acetylpyrazine as substrate. This reaction can be performed under mild reaction conditions with clean reaction profiles and a simple workup procedure.

关键词： One–pot synthesis     b-amino ketone     char sulfonic acid     2-acetylpyrazine     catalysis    

HTML PDF 收藏

One-step synthesis of

Kuiyi YOU, Fangfang ZHAO, Xueyan LONG, Pingle LIU, Qiuhong AI, Hean LUO

《化学科学与工程前沿（英文）》 2012年 第6卷 第4期   页码 389-394 doi: 10.1007/s11705-012-1218-0

摘要： A simple and efficient approach for the synthesis of -caprolactam via the liquid phase nitrosation of cyclohexane and nitrosyl sulfuric acid in the presence of concentrated sulfuric acid has been developed. A series of novel AlVPO composites were prepared by an impregnation method and the composites were then employed to catalyze the nitrosation reaction of cyclohexane and nitrosyl sulfuric acid. Compared to the reaction using fuming sulfuric acid, the selectivity for the desired product was significantly improved using this one-step catalytic process. This method affords a shortcut to prepare -caprolactam and its analogs from cyclohexane.

关键词： cyclohexane     ?-caprolactam     AlVPO composite catalysts     one-step synthesis     concentrated sulfuric acid    

HTML PDF 收藏

DNA alkylation promoted by an electron-rich quinone methide intermediate

Chengyun Huang,Steven E. Rokita

《化学科学与工程前沿（英文）》 2016年 第10卷 第2期   页码 213-221 doi: 10.1007/s11705-015-1541-3

摘要： Biological application of conjugates derived from oligonucleotides and quinone methides have previously been limited by the slow exchange of their covalent self-adducts and subsequent alkylation of target nucleic acids. To enhance the rates of these processes, a new quinone methide precursor with an electron donating substituent has been prepared. Additionally, this substituent has been placed to the nascent -methylene group of the quinone methide for maximum effect. A conjugate made from this precursor and a 5'-aminohexyloligonucleotide accelerates formation of its reversible self-adduct and alkylation of its complementary DNA as predicted from prior model studies.

关键词： quione methide     DNA alkylation     reversible covalent reaction     bioconjugation     target-directed modification of nucleic acids    

HTML PDF 收藏

ZnZr/HZSM-5 as efficient catalysts for alkylation of benzene with carbon dioxide

《化学科学与工程前沿（英文）》 2023年 第17卷 第4期   页码 404-414 doi: 10.1007/s11705-022-2215-6

摘要： Alkylation of benzene with carbon dioxide and hydrogen to produce toluene and xylene could increase the added-value of surplus benzene as well as relieve environmental problems like green-house effect. In this work, the alkylation benzene with carbon dioxide and hydrogen reaction was proceeded by using the mixture of zinc-zirconium oxide and HZSM-5 as bifunctional catalyst. The equivalent of Zn/Zr = 1 displays the best catalytic performance at 425 °C and 3.0 MPa, and benzene conversion reaches 42.9% with a selectivity of 90% towards toluene and xylene. Moreover, the carbon dioxide conversion achieves 23.3% and the carbon monoxide selectivity is lower than 35%, indicating that more than 50% carbon dioxide has been effectively incorporated into the target product, which is the best result as far as we know. Combined with characterizations, it indicated that the Zn and Zr formed a solid solution under specific conditions (Zn/Zr = 1). The as-formed solid solution not only possesses a high surface area but also provides a large amount of oxygen vacancies. Additionally, the bifunctional catalyst has excellent stabilities that could keep operating without deactivation for at least 80 h. This work provides promising industrial applications for the upgrading of aromatics.

关键词： carbon dioxide     alkylation of benzene     solid solution catalyst     bifunctional catalyst    

HTML PDF 收藏

Catalytic process modeling and sensitivity analysis of alkylation of benzene with ethanol over MIL-101

Ehsan Rahmani, Mohammad Rahmani

《化学科学与工程前沿（英文）》 2020年 第14卷 第6期   页码 1100-1111 doi: 10.1007/s11705-019-1891-3

摘要： A solvothermal method was used to synthesize MIL-101(Fe) and MIL-88(Fe), which were used for alkylation of benzene. The synthesized catalysts were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscope, dynamic light scattering, and BET techniques. Metal-organic frameworks (MOFs) were modeled to investigate the catalytic performance and existence of mass transfer limitations. Calculated effectiveness factors revealed absence of internal and external mass transfer. Sensitivity analysis revealed best operating conditions over MIL-101 at 120°C and 5 bar and over MIL-88 at 142°C and 9 bar.

关键词： MOFs     alkylation     ethylbenzene     catalysts pellet model     kinetic model     sensitivity analysis    

HTML PDF 收藏

Stability analysis of alkaline nitrobenzene-containing wastewater by a catalyzed Fe-Cu treatment process

FAN Jinhong, XU Wenying, GAO Tingyao, MA Luming

《环境科学与工程前沿（英文）》 2007年 第1卷 第4期   页码 504-508 doi: 10.1007/s11783-007-0081-6

摘要： Iron and copper bimetallic system (catalyzed Fe-Cu process) is a promising technology for alkaline nitrobenzene-containing wastewater treatment. However, little is currently known about the changes of treatment efficiency with time

关键词： technology     bimetallic     catalyzed     nitrobenzene-containing wastewater     efficiency    

HTML PDF 收藏

酶法合成sn-2棕榈酸甘油酯的研究进展 Review

韦伟, 孙聪, 王小三, 金青哲, Xuebing Xu, Casimir C. Akoh, 王兴国

《工程（英文）》 2020年 第6卷 第4期   页码 406-414 doi: 10.1016/j.eng.2020.02.008

摘要：

人乳脂（human milk fat, HMF）是婴儿重要的能量和营养来源，甘油三酯（TAG）在人乳脂中的含量约为98%，其具有独特的分子结构。HMF在甘油碳骨架sn-2位的棕榈酸（PA）含量超过70%，而在sn-1,3位高度富集多不饱和脂肪酸。研究表明，HMF中特定的TAG结构在婴儿生长过程中起重要作用。Sn-2棕榈酸甘油酯是一种结构TAG，主要由1,3-二油酸-2-棕榈酸甘油三酯组成，将其添加到婴幼儿配方奶粉中可以模拟HMF的TAG结构。本文综述了过去25年中酶法合成sn-2棕榈酸甘油酯的研究进展及其在实验室条件下的制备流程，重点分析了结构TAG合成过程中所用的商业化sn-1,3位选择性脂肪酶、TAG结构分析的常用方法，以及一些市售sn-2棕榈酸甘油酯产品。另外，本文还对酶法合成sn-2棕榈酸甘油酯的前景进行了展望。

关键词： 结构甘油三酯     棕榈酸     人乳替代脂     酶法合成反应     sn-2棕榈酸甘油酯     定量分析    

HTML PDF 收藏

标题 作者 时间 类型 操作

Octane compositions in sulfuric acid catalyzed isobutane/butene alkylation products: experimental and

Lina Liang, Youzhi Liu, Weizhou Jiao, Qiaoling Zhang, Chao Zhang

期刊论文

Benzene alkylation with long chain olefins catalyzed by ionic liquids: a review

QIAO Congzhen, CAI Yonghong, GUO Quanhui

期刊论文

Continuous reaction performances of benzene alkylation with long chain olefins catalyzed by ionic liquid

QIAO Congzhen, LI Chengyue

期刊论文

Alkylation of benzene with propylene catalyzed by FeCl3-chloropyridine ionic liquid

SUN Xuewen, ZHAO Suoqi, LI Hui

期刊论文

Comparison of prechilling stratification and sulfuric acid scarification on seed germination of

Nan WANG, Jing GAO, Suiqi ZHANG, Feng YAN

期刊论文

Resistance to acid degradation, sorptivity, and setting time of geopolymer mortars

Osama A MOHAMED; Rania AL-KHATTAB; Waddah AL-HAWAT

期刊论文

Visbreaking of heavy petroleum oil catalyzed by SO/ZrO solid super-acid doped with Ni or Sn

JING Ping, LI Qingbiao, HAN Mei, SUN Daohua, JIA Lishan, FANG Weiping

期刊论文

绿色化的磷复肥生产集成工艺

冯怡生

期刊论文

One-pot three-component Mannich reaction catalyzed by sucrose char sulfonic acid

Qiong XU, Zhigao YANG, Dulin YIN, Jihui WANG

期刊论文

One-step synthesis of

Kuiyi YOU, Fangfang ZHAO, Xueyan LONG, Pingle LIU, Qiuhong AI, Hean LUO

期刊论文

DNA alkylation promoted by an electron-rich quinone methide intermediate

Chengyun Huang,Steven E. Rokita

期刊论文

ZnZr/HZSM-5 as efficient catalysts for alkylation of benzene with carbon dioxide

期刊论文

Catalytic process modeling and sensitivity analysis of alkylation of benzene with ethanol over MIL-101

Ehsan Rahmani, Mohammad Rahmani

期刊论文

Stability analysis of alkaline nitrobenzene-containing wastewater by a catalyzed Fe-Cu treatment process

FAN Jinhong, XU Wenying, GAO Tingyao, MA Luming

期刊论文

酶法合成sn-2棕榈酸甘油酯的研究进展

韦伟, 孙聪, 王小三, 金青哲, Xuebing Xu, Casimir C. Akoh, 王兴国

期刊论文