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Effect of different acid anions on highly efficient Ce-based catalysts for selective catalytic reductionof NO with NH₃

《化学科学与工程前沿（英文）》 2023年第17卷第10期页码 1399-1411 doi: 10.1007/s11705-023-2345-5

摘要： Three kinds of Ce-based catalysts (CePO₄, CeVO₄, Ce₂(SO₄)₃) were synthesized and used for the selective catalytic reduction (SCR) of NO by NH₃. NH₃-SCR performances were conducted in the temperature range of 80 to 400 °C. The catalytic efficiencies of the three catalysts are as follow: CePO₄ > CeVO₄ > Ce₂(SO₄)₃, which is in agreement with their abilities of NH₃ adsorption capacities. The highest NO conversion rate of CePO₄ could reach about 95%, and the catalyst had more than 90% NO conversion rate between 260 and 320 °C. The effect of PO₄^3–, VO₄^3– and SO₄^2– on NH₃-SCR performances of Ce-based catalysts was systematically investigated by the X-ray photoelectron spectroscopy analysis, NH₃ temperature programmed desorption, H₂ temperature programmed reduction and field emission scanning electron microscopy tests. The key factors that can enhance the SCR are the existence of Ce⁴⁺, large NH₃ adsorption capacity, high and early H₂ consumptions, and suitable microstructures for gas adsorption. Finally, CePO₄ and CeVO₄ catalysts also exhibited relatively strong tolerance of SO₂, and the upward trend about 8% was detected due to the sulfation enhancement by SO₂ for Ce₂(SO₄)₃.

关键词： CePO₄ CeVO₄ Ce₂(SO₄)₃ selective catalytic reduction NO removal

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An investigation of the CHOH and CO selectivity of CO hydrogenation over Cu–Ce–Zr catalysts

《化学科学与工程前沿（英文）》 2022年第16卷第6期页码 950-962 doi: 10.1007/s11705-022-2162-2

摘要： A series of Cu–Ce–Zr catalysts with different Ce contents are applied to the hydrogenation of CO₂ to CO/CH₃OH products. The Cu–Ce–Zr catalyst with 2 wt% Ce loading shows higher CO selectivity (S_CO = 0.0%–87.8%) from 200–300 °C, while the Cu–Ce–Zr catalyst with 8 wt% Ce loading presents higher CO₂ conversion (

X C O 2

= 5.4%–15.6%) and CH₃OH selectivity (

S C H 3 O H

= 97.8%–40.6%). The number of hydroxyl groups and solid solution nature play a significant role in changing the reaction pathway. The solid solution enhances the CO₂ adsorption ability. At the CO₂ adsorption step, a larger number of hydroxyl groups over the Cu–Ce–Zr catalyst with 8 wt% Ce loading leads to the production of H-containing adsorption species. At the CO₂ hydrogenation step, a larger number of hydroxyl groups assists in encouraging the further hydrogenation of intermediate species to CH₃OH and improving the hydrogenation rate. Hence, the Cu–Ce–Zr catalyst with 8 wt% Ce loading favors CH₃OH selectivity and CO₂ activation, while CO is preferred on the Cu–Ce–Zr catalyst with 2 wt% Ce loading, a smaller number of hydroxyl groups and a solid solution nature. Additionally, high-pressure in situ diffuse reflectance infrared Fourier transform spectroscopy shows that CO is produced from formate decomposition and that both monodentate formate and bidentate formate are active intermediate species of CO₂ hydrogenation to CH₃OH.

关键词： CO₂ hydrogenation Cu–Ce–Zr hydroxyls CO/CH₃OH selectivity

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Effects of La, Ce on nitrogen removal in sequencing batch reactor

Qing XIA , Rui LIANG , Yuning HONG , Lili DING , Hongqiang REN , Yuxiang MAO , Mingyu ZHAO ,

《环境科学与工程前沿（英文）》 2009年第3卷第3期页码 369-374 doi: 10.1007/s11783-009-0036-1

摘要： Batch experiments were conducted to study the short-term biological effects of rare earth ions (La, Ce) and their mixture on the nitrogen removal in a sequencing batch reactor (SBR). The data showed that higher NH―N removal rate, total inorganic nitrogen removal efficiency, and denitrification efficiency were achieved at lower concentrations of rare earth elements (REEs) (<1mg/L). In the first hour of the aeration stage of SBR, the presence of REEs increased the total inorganic nitrogen removal efficiency and NH―N removal efficiency by 15.7% and 10%―15%, respectively. When the concentrations of REEs were higher than 1mg/L, the total inorganic nitrogen removal efficiency decreased, and nitrate was found to accumulate in the effluent. When the concentrations of REEs was up to 50.0mg/L, the total inorganic nitrogen removal efficiency was less than 30% of the control efficiency with a high level of nitrate. Lower concentrations of REEs were found to accelerate the nitrogen conversion and removal in SBR.

关键词： rare earth La³⁺ Ce³⁺ inorganic nitrogen nitrogen removal sequencing batch reactor

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H₂ 对Pt-Ba-Ce /γ-Al₂O₃ 催化剂NO_x 存储和还原机理的影响研究 Article

王攀, 裔静, 孙川, 罗鹏, 雷利利

《工程（英文）》 2019年第5卷第3期页码 568-575 doi: 10.1016/j.eng.2019.02.005

摘要：

本研究采用浸渍法制备了Pt-Ba-Ce/γ-Al₂O₃催化剂，利用实验评价了H₂ 对NSR（NO_x storage and reduction）催化剂存储和还原机理的影响，并采用综合表征技术研究了Pt-Ba-Ce /γ-Al₂O_{3_x、CeO₂ 和BaCO₃ 峰很好地分散在γ-Al₂O₃ 上，X 射线光电子能谱（XPS）检测到Ce3+ 和Ce4+ 之间的差异，Ce3+ 和Ce4+ 促进了活性氧在催化剂上的迁移。}

关键词： Pt–Ba–Ce/γ-Al₂O₃ 催化剂，物理化学性质，NO_x存储和还原，NO_x 排放

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含参数初值整定和自适应鲁棒方法的3-RPS气动并联平台位姿控制 Article

Guo-liang TAO,Ce SHANG,De-yuan MENG,Chao-chao ZHOU

《信息与电子工程前沿（英文）》 2017年第18卷第3期页码 303-316 doi: 10.1631/FITEE.1500353

摘要：本文讨论了关于气缸驱动的3-RPS并联平台的一种控制方法。研究对象使用气动比例方向阀控制各驱动气缸，并建立了系统的运动学和动力学模型，采用基于反步法和在线参数辨识的自适应鲁棒控制器作为主要控制方式。

关键词：参数初值整定；自适应鲁棒控制；并联机构；气缸

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Modeling of Ce(IV) transport through a dispersion flat combined liquid membrane with carrier P507

Liang PEI,Liming WANG,Zhanying MA

《环境科学与工程前沿（英文）》 2014年第8卷第4期页码 503-509 doi: 10.1007/s11783-013-0540-1

摘要： A mathematical model for the transport of Ce(IV) from hydrochloric acid solutions through dispersion flat combined liquid membrane (DFCLM) with contain 2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester (P507) as the carrier, dissolved in kerosene as the membrane solution have been studied. This process of facilitated transport, based on membrane technology, is a variation on the conventional technique of solvent extraction and may be described mathematically using Fick’s second law. The equations for transport velocity are derived considering the diffusion of P507 and its metallic complexes through the liquid membrane. In this work, the system is considered to be in a transient state, and chemical reaction between Ce(IV) and the carrier to take place only at the solvent–aqueous interfaces. Model concentration profiles are obtained for the Ce(IV), from which extraction velocities are predicted. The experimental and simulated Ce(IV) extractions showed similar tendencies for a high Ce(IV) concentration and acidity case.The model results indicate that high initial Ce(IV) concentrations and acidity both have detrimental effects on Ce(IV) extraction and stripping. The diffusion coefficient of Ce(IV) in the membrane and the thickness of diffusion layer between feed phase and membrane phase are obtained and the values are 6.31 × 10 m ·s and 31.2 μm, respectively. The results are in good agreement with experimental results.

关键词： Dispersion flat combined liquid membrane (DFCLM) dispersion phase feed phase 2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester Ce (IV)

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Promotion of transition metal oxides on the NH

Weiman Li, Haidi Liu, Yunfa Chen

《环境科学与工程前沿（英文）》 2017年第11卷第2期 doi: 10.1007/s11783-017-0914-x

摘要： Manganese and chromium oxides promote the NH -SCR activity of Zr-Ce mixed oxide. Cr-Zr-Ce mixed oxide exhibited>80% NO conversion at a wide temperature window. More acid sites and higher reducibility may responsible for the high SCR ability. Chromium oxide and manganese oxide promoted ZrO -CeO catalysts were prepared by a homogeneous precipitation method for the selective catalytic reduction of NO with NH . A series of characterization including X-ray diffraction (XRD), high-resolution transmission electron microscope (HR-TEM), Brunauer–Emmett–Teller (BET) surface area analysis, H temperature-programmed reduction (H -TPR), and X-ray photoelectron spectroscopy (XPS) were used to evaluate the influence of the physicochemical properties on NH -SCR activity. Cr-Zr-Ce and Mn-Zr-Ce catalysts are much more active than ZrO -CeO binary oxide for the low temperature NH -SCR, mainly because of the high specific surface area, more surface oxygen species, improved reducibility derived from synergistic effect among different elements. Mn-Zr-Ce catalyst exhibited high tolerance to SO and H O. Cr-Zr-Ce mixed oxide exhibited>80% NO conversion at a wide temperature window of 100°C–300°C. DRIFT studies showed that the addition of Cr is beneficial to the formation of Bronsted acid sites and prevents the formation of stable nitrate species because of the presence of Cr . The present mixed oxide can be a candidate for the low temperature abatement of NO .

关键词： NH₃-selective catalytic reduction NO_x Low temperature Cr-Zr-Ce

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Special issue on the Asian Congress on Biotechnology 2011

Bang-Ce YE

《化学科学与工程前沿（英文）》 2012年第6卷第2期页码 125-125 doi: 10.1007/s11705-012-1291-4

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Microwave-assisted catalytic oxidation of gaseous toluene with a Cu-Mn-Ce/cordierite honeycomb catalyst

Longli Bo, Shaoyuan Sun

《化学科学与工程前沿（英文）》 2019年第13卷第2期页码 385-392 doi: 10.1007/s11705-018-1738-3

摘要： A novel Cu-Mn-Ce/cordierite honeycomb catalyst was prepared by an incipient wetness method and the catalyst was characterized. The active ingredients were present as various spinel species of Cu, Mn and Ce oxides with different valences and they were unevenly dispersed over the surface of the catalyst. The catalytic oxidation of gaseous toluene was primarily investigated using a fixed bed reactor under microwave heating in the continuous flow mode. Under the optimal conditions of 6.7 wt-% loading of the active component, a bed temperature of 200°C, a flow rate of 0.12 m ·h and an initial concentration of toluene of 1000 mg·m , the removal and mineralization efficiencies of toluene were 98% and 70%, respectively. Thus the use of the microwave effectively improved the oxidation of toluene and this is attributed to dipole polarization and hotspot effects. After four consecutive cycles (a total of 1980 min), the Cu-Mn-Ce/cordierite catalyst still exhibited excellent catalytic activity and structural stability, and the toluene removal was higher than 90%. This work demonstrates the possibility of treating volatile organic compounds in exhaust gases by microwave-assisted catalytic oxidation.

关键词： microwave catalytic oxidation toluene Cu-Mn-Ce/cordierite mineralization

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Reductive amination of -hexanol to -hexylamine over Ni–Ce/-AlO catalysts

《化学科学与工程前沿（英文）》 2023年第17卷第1期页码 82-92 doi: 10.1007/s11705-022-2181-z

摘要： The amination of alkyl alcohols is one of the most promising paths in synthesis of aliphatic amines. Herein, cerium doped nickel-based catalysts were synthesized and tested in a gas-phase amination of n-hexanol to n-hexylamine. It was found that the activity of the Ni/γ-Al₂O₃ catalyst is significantly improved by doping an appropriate amount of cerium. The presence of cerium effectively inhibits the agglomeration of nickel particle, resulting in better Ni dispersion. As Ni particle size plays critical role on the catalytic activity, higher turnover frequency of n-hexanol amination was achieved. Cerium doping also improves the reduction ability of nickel and enhances the interactions between Ni and the catalyst support. More weak acid sites were also found in those cerium doped catalysts, which promote another key step—ammonia dissociative adsorption in this reaction system. The overall synergy of Ni nanoparticles and acid sites of this Ni–Ce/γ-Al₂O₃ catalyst boosts its superior catalytic performance in the amination of n-hexanol.

关键词： amination alcohol cerium nickel acidity interaction

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PM-support interfacial effect and oxygen mobility in Pt, Pd or Rh-loaded (Ce,Zr,La)O catalysts

《环境科学与工程前沿（英文）》 2021年第15卷第4期 doi: 10.1007/s11783-020-1369-z

摘要：

• Pt/CZL exhibits the optimum catalytic performance for HC and NO_x elimination.

关键词： Precious metal-loaded (Ce Zr La)O₂ catalysts Oxygen mobility Catalytic performance

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Catalytic performance of Co-Mo-Ce-K/γ-Al

Yuqiong ZHAO, Yongfa ZHANG

《化学科学与工程前沿（英文）》 2010年第4卷第4期页码 457-460 doi: 10.1007/s11705-010-0524-7

摘要： The catalytic performance of Co-Mo-Ce-K/γ-Al O catalyst for the shift reaction of CO in coke oven gas is investigated using X-ray diffraction (XRD) and temperature-programmed reduction (TPR). The results indicate that Ce and K have a synergistic effect on promoting the catalytic activity, and the Co-Mo-Ce-K/γ-Al O catalyst with 3.0 wt-% CeO and 6.0 wt-% K O exhibits the highest activity. CeO favors Co dispersion and mainly produces an electronic effect. TPR characterization results indicate that the addition of CeO -K O in the Co-Mo-Ce-K/γ-Al O catalyst decreases the reduction temperature of active components, and part of octahedrally coordinated Mo transforms into tetrahedrally coordinated Mo , which has a close relationship with the catalytic activity.

关键词： coke oven gas water gas shift reaction sulfur-tolerant catalyst cerium dioxide

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Principle and curve of planetary indexing cam mechanisms

LIU Ming-tao, ZHANG Ce, YANG Yu-hu

《机械工程前沿（英文）》 2006年第1卷第4期页码 475-478 doi: 10.1007/s11465-006-0063-6

摘要： A new type of planetary indexing cam mechanism called type !c is presented. The transmission principle of type !c is discussed. Based on the principle of formation of conjugate tooth contour, the equations of the cam s pitch curve are derived. The continuity and symmetry of the cam s pitch curve are also analyzed. It can be concluded that: 1) This type has no output institution so the output precision can be improved; 2) The asymmetrical two-ring structure is used to overcome dead point and its phase angle is equal to (π - 2π/n); 3) The continuous condition of the cam s pitch curve is that the average transmission ratio is -n in an intermittent motion period.

关键词： continuity planetary average transmission symmetry intermittent