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Development of an H reduction and moderate oxidation method for 3,5-dimethylpyridine hydrogenation in

《化学科学与工程前沿（英文）》 2022年第16卷第12期页码 1807-1817 doi: 10.1007/s11705-022-2243-2

摘要： The Ru/C catalyst prepared by impregnation method was used for hydrogenation of 3,5-dimethylpyridine in a trickle bed reactor. Under the same reduction conditions (300 °C in H₂), the catalytic activity of the non-in-situ reduced Ru/C-n catalyst was higher than that of the in-situ reduced Ru/C-y catalyst. Therefore, an in-situ H₂ reduction and moderate oxidation method was developed to increase the catalyst activity. Moreover, the influence of oxidation temperature on the developed method was investigated. The catalysts were characterized by Brunauer–Emmett–Teller method, hydrogen temperature programmed reduction H₂-TPR, hydrogen temperature-programmed dispersion (H₂-TPD), X-ray diffraction, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, O₂ chemisorption and oxygen temperature-programmed dispersion (O₂-TPD) analyses. The results showed that there existed an optimal Ru/RuO_x ratio for the catalyst, and the highest 3,5-dimethylpyridine conversion was obtained for the Ru/C-i1 catalyst prepared by in-situ H₂ reduction and moderate oxidation (oxidized at 100 °C). Excessive oxidation (200 °C) resulted in a significant decrease in the Ru/RuO_x ratio of the in-situ H₂ reduction and moderate oxidized Ru/C-i2 catalyst, the interaction between RuO_x species and the support changed, and the hard-to-reduce RuO_x species was formed, leading to a significant decrease in catalyst activity. The developed in-situ H₂ reduction and moderate oxidation method eliminated the step of the non-in-situ reduction of catalyst outside the trickle bed reactor.

关键词： Ru/C catalyst in-situ H₂ reduction and moderate oxidation in-situ reduction non-in-situ reduction hydrogenation of 3 5-dimethylpyridine

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grown TiN/N-TiO composite for enhanced photocatalytic H evolution activity

《能源前沿（英文）》 2021年第15卷第3期页码 721-731 doi: 10.1007/s11708-021-0766-8

摘要： Titanium nitride (TiN) decorated N-doped titania (N-TiO₂) composite (TiN/N-TiO₂) is fabricated via an in situ nitridation using a hydrothermally synthesized TiO₂ and melamine (MA) as raw materials. After the optimization of the reaction condition, the resultant TiN/N-TiO₂ composite delivers a hydrogen evolution activity of up to 703 μmol/h under the full spectrum irradiation of Xe-lamp, which is approximately 2.6 and 32.0 times more than that of TiO₂ and TiN alone, respectively. To explore the underlying photocatalytic mechanism, the crystal phase, morphology, light absorption, energy band structure, element composition, and electrochemical behavior of the composite material are characterized and analyzed. The results indicate that the superior activity is mainly caused by the in situ formation of plasmonic TiN and N-TiO₂ with intimate interface contact, which not only extends the spectral response range, but also accelerates the transfer and separation of the photoexcited hot charge carrier of TiN. The present study provides a fascinating approach to in situ forming nonmetallic plasmonic material/N-doped TiO₂ composite photocatalysts for high-efficiency water splitting.

关键词： photocatalytic H₂ evolution TiN/N-TiO₂ composite plasmonic effect in-situ nitridation

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Polyolefin-nanocomposites with special properties by in-situ polymerization

Walter Kaminsky

《化学科学与工程前沿（英文）》 2018年第12卷第3期页码 555-563 doi: 10.1007/s11705-018-1715-x

摘要：

Exceptionally strong polyolefin nanocomposites are synthesized by in-situ polymerization using soluble metallocene/methylaluminoxane (MAO) as catalysts in a two-step process. First, the soluble metallocene/MAO or other single site catalysts are absorbed on the surface of the nanofillers. Then by addition of ethene or propene, a polyolefin film is formed, covering the nanoparticles, layered silicates, or fibers. The resulting polyethylene and polypropylene nanocomposites are characterized by better physical and chemical properties such as stiffness, gas barrier properties, degradation temperatures, and crystallization rates. They show better mechanical properties than materials produced by mechanical blending. The thickness of the polyolefin can be controlled by the pressure of ethene or propene and by the polymerization time. Carbon fibers and carbon nanotubes are covered with isotactic or syndiotactic polypropylene. Because of the hydrophobic character of the carbon surface, the polymer is drawn on the fiber. This leads to a reinforced combined polymer with special properties. The crystallization temperature is 10 °C higher and therefore the crystallization rate up to 20 times faster than that of pure syndiotactic polypropylene. The form stability increases by 100% if 3 wt-% of carbon nanotubes are incorporated.

关键词： polyolefin nanocomposites metallocenes methylaluminoxane

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Thermodynamic analysis of liquid phase in situ hydrogenation of glycerol for 1,3-propanediol synthesis

Kun OUYANG, Yu HUANG, Haoyi CHEN, Tao LI, Fahai CAO, Dingye FANG

《化学科学与工程前沿（英文）》 2011年第5卷第1期页码 67-73 doi: 10.1007/s11705-010-0541-6

摘要： Based on the combination of the glycerol aqueous-phase reforming (APR) and catalytic hydrogenation of glycerol, a novel reaction system of liquid phase in situ hydrogenation of glycerol for the synthesis of 1,3-propanediol is proposed, in which hydrogen is produced from glycerol aqueous-phase reforming in the same reactor. In this new system, the glycerol is the raw material of the aqueous-phase reforming reaction; the hydrogen generated from the APR of glycerol can be quickly transformed to the in situ hydrogenation of glycerol to produce 1,3-propanediol, which can improve the selectivity of hydrogen for the APR process of glycerol. Moreover, thermodynamic calculation of the coupling processes was carried out, and standard molar enthalpies and equilibrium constants of foregoing reactions were obtained. The above calculation results indicate that the combination process is feasible for 1,3-propanediol synthesis.

关键词： glycerol aqueous-phase reforming 1 3-propanediol in-situ reduction

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In situ DRIFTS study of photocatalytic CO 2 reduction under UV irradiation

Jeffrey C. S. WU, Chao-Wei HUANG,

《化学科学与工程前沿（英文）》 2010年第4卷第2期页码 120-126 doi: 10.1007/s11705-009-0232-3

摘要： Photocatalytic reduction of CO on TiO and Cu/TiO photocatalysts was studied by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) under UV irradiation. The photocatalysts were prepared by sol-gel method via controlled hydrolysis of titanium (IV) butoxide. Copper precursor was loaded onto TiO during sol-gel procedure. A large amount of adsorbed HO and surface OH groups was detected at 25°C on the TiO photocatalyst after being treated at 500°C under air stream. Carbonate and bicarbonate were formed rapidly due to the reaction of CO with oxygen-vacancy and OH groups, respectively, on TiO surface upon CO adsorption. The IR spectra indicated that, under UV irradiation, gas-phase CO further combined with oxygen-vacancy and OH groups to produce more carbonate or bicarbonate. The weak signals of reaction intermediates were found on the IR spectra, which were due to the slow photocatalytic CO reduction on photocatalysts. Photogenerated electrons merge with H ions to form H atoms, which progressively reduce CO to form formic acid, dioxymethylene, formaldehyde and methoxy as observed in the IR spectra. The well-dispersed Cu, acting as the active site significantly increases the amount of formaldehyde and dioxymethylene, thus promotes the photoactivity of CO reduction on Cu/TiO. A possible mechanism of the photocatalytic CO reduction is proposed based on these intermediates and products on the photocatalysts.

关键词： irradiation oxygen-vacancy Photocatalytic reduction Carbonate butoxide

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In-situ condition monitoring of reinforced concrete structures

Sanjeev Kumar VERMA,Sudhir Singh BHADAURIA,Saleem AKHTAR

《结构与土木工程前沿（英文）》 2016年第10卷第4期页码 420-437 doi: 10.1007/s11709-016-0336-z

摘要： Performance of concrete structures is significantly influenced and governed by its durability and resistance to environmental or exposure conditions, apart from its physical strength. It can be monitored, evaluated and predicted through modeling of physical deterioration mechanisms, performance characteristics and parameters and condition monitoring of in situ concrete structures. One such study has been conducted using Non-destructive testing equipment in the city of Bhopal and around located in India. Some selected parameters influencing durability of reinforced concrete (RC) structures such as concrete cover, carbonation depth, chloride concentration, half cell potential and compressive strength have been measured, for establishing correlation among various parameters and age of structures. Effects of concrete cover and compressive strength over the variation of chloride content with time are also investigated.

关键词： concrete carbonation chloride corrosion monitoring models

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催化氧化净化黄磷尾气中的磷和硫

宁平,Hans-JörgBart,王学谦,马丽萍,陈梁

《中国工程科学》 2005年第7卷第6期页码 27-35

摘要：研究了用普通活性炭和自制催化剂KU2催化氧化净化黄磷尾气的方法；讨论了固定床系统中常压下、温度20～140℃，催化剂上磷和硫化氢的吸附特征。KU2和活性炭都能通过催化氧化过程有效脱除黄磷尾气中的P₄，PH₃和H₂S杂质，随着反应温度和氧含量增加可显著提高净化效果，在最优条件下

关键词：催化剂催化氧化 H₂S P₄ PH₃ 固定床

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Organics Recovery from Waste Activated Sludge In-situ Driving Efficient Nitrogen Removal from Mature

Fangzhai Zhang,Shang Ren,Haoran Liang,Zhaozhi Wang,Ying Yan,Jiahui Wang,Yongzhen Peng,

《工程（英文）》 doi: 10.1016/j.eng.2023.03.005

摘要： The sustainable recovery and utilization of sludge bioenergy within a circular economy context has drawn increasing attention, but there is currently a shortage of reliable technology. This study presents an innovative biotechnology based on free nitrous acid (FNA) to realize sustainable organics recovery from waste activated sludge (WAS) in-situ, driving efficient nitrogen removal from ammonia rich mature landfill leachate by integrating partial nitrification, fermentation, and denitrification process (PN/DN–F/DN). First, ammonia ((1708.5 ± 142.9) mg·L⁻¹) in mature landfill leachate is oxidized to nitrite in the aerobic stage of a partial nitrification coupling denitrification sequencing batch reactor (PN/DN-SBR), with nitrite accumulation ratio of 95.4% ± 2.5%. Then, intermediate effluent (NO₂⁻–N = (1196.9 ± 184.2) mg·L⁻¹) of the PN/DN-SBR, along with concentrated WAS (volatile solids (VSs) = (15119.8 ± 2484.2) mg·L⁻¹), is fed into an anoxic reactor for fermentation coupling denitrification process (F/DN-SBR). FNA, the protonated form of nitrite, degrades organics in the WAS to the soluble fraction by the biocidal effect, and the released organics are utilized by denitrifiers to drive NO_x⁻ reduction. An ultra-fast sludge reduction rate of 4.89 kg·m⁻³·d⁻¹ and nitrogen removal rate of 0.46 kg·m⁻³·d⁻¹ were realized in the process. Finally, F/DN-SBR effluent containing organics is refluxed to PN/DN-SBR for secondary denitrification in the post anoxic stage. After 175 d operation, an average of 19350.6 mg chemical oxygen demand organics were recovered per operational cycle, with 95.2% nitrogen removal and 53.4% sludge reduction. PN/DN–F/DN is of great significance for promoting a paradigm transformation from energy consumption to energy neutral, specifically, the total benefit in equivalent terms of energy was 291.8 kW·h·t⁻¹ total solid.

关键词： Waste activated sludge Bioresource recovery Simultaneous treatment of wastewater and sludge Mature landfill leachate Free nitrous acid

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density measurement for plastic injection molding via ultrasonic technology

《机械工程前沿（英文）》 2022年第17卷第4期 doi: 10.1007/s11465-022-0714-2

摘要： Density variation during the injection molding process directly reflects the state of plastic melt and contains valuable information for process monitoring and optimization. Therefore, in-situ density measurement is of great interest and has significant application value. The existing methods, such as pressure−volume−temperature (PVT) method, have the shortages of time-delay and high cost of sensors. This study is the first to propose an in-situ density measurement method using ultrasonic technology. The analyses of the time-domain and frequency-domain signals are combined in the proposed method. The ultrasonic velocity is obtained from the time-domain signals, and the acoustic impedance is computed through a full-spectral analysis of the frequency-domain signals. Experiments with different process conditions are conducted, including different melt temperature, injection speed, material, and mold structure. Results show that the proposed method has good agreement with the PVT method. The proposed method has the advantages of in-situ measurement, non-destructive, high accuracy, low cost, and is of great application value for the injection molding industry.

关键词： ultrasonic measurement melt density in-situ measurement injection molding

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Comparison of different valent iron on anaerobic sludge digestion: Focusing on oxidation reduction potential

《环境科学与工程前沿（英文）》 2022年第16卷第6期 doi: 10.1007/s11783-021-1514-3

摘要：

• ORP value from −278.71 to −379.80 mV showed indiscernible effects on methane yield.

关键词： Enhanced anaerobic sludge digestion Different iron valence Oxidation reduction potential Dissolved organic nitrogen Microbial community

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Biological conversion pathways of sulfate reduction ammonium oxidation in anammox consortia

Zhen Bi, Deqing Wanyan, Xiang Li, Yong Huang

《环境科学与工程前沿（英文）》 2020年第14卷第3期 doi: 10.1007/s11783-019-1217-1

摘要： The SRAO phenomena tended to occur only under certain conditions. High amount of biomass and non-anaerobic condition is requirement for SRAO. Anammox bacteria cannot oxidize ammonium with sulfate as electron acceptor. AOB and AnAOB are mainly responsible for ammonium conversion. Heterotrophic sulfate reduction mainly contributed to sulfate conversion. For over two decades, sulfate reduction with ammonium oxidation (SRAO) had been reported from laboratory experiments. SRAO was considered an autotrophic process mediated by anammox bacteria, in which ammonium as electron donor was oxidized by the electron acceptor sulfate. This process had been attributed to observed transformations of nitrogenous and sulfurous compounds in natural environments. Results obtained differed largely for the conversion mole ratios (ammonium/sulfate), and even the intermediate and final products of sulfate reduction. Thus, the hypothesis of biological conversion pathways of ammonium and sulfate in anammox consortia is implausible. In this study, continuous reactor experiments (with working volume of 3.8L) and batch tests were conducted under normal anaerobic (0.2≤DO<0.5 mg/L) / strict anaerobic (DO<0.2 mg/L) conditions with different biomass proportions to verify the SRAO phenomena and identify possible pathways behind substrate conversion. Key findings were that SRAO occurred only in cases of high amounts of inoculant biomass under normal anaerobic condition, while absent under strict anaerobic conditions for same anammox consortia. Mass balance and stoichiometry were checked based on experimental results and the thermodynamics proposed by previous studies were critically discussed. Thus anammox bacteria do not possess the ability to oxidize ammonium with sulfate as electron acceptor and the assumed SRAO could, in fact, be a combination of aerobic ammonium oxidation, anammox and heterotrophic sulfate reduction processes.

关键词： Anammox bacteria Autotrophic Biological conversion Sulfate reducing ammonium oxidation (SRAO)

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Investigate of in situ sludge reduction in sequencing batch biofilm reactor: Performances, mechanisms

Yonglei Wang, Baozhen Liu, Kefeng Zhang, Yongjian Liu, Xuexin Xu, Junqi Jia

《环境科学与工程前沿（英文）》 2018年第12卷第5期 doi: 10.1007/s11783-018-1077-0

摘要：

Microbial metabolism uncoupling, sludge decay is the main mechanism to promote in situ sludge reduction on this biofilm system.

The main reduction mechanism inside the biofilm is sludge decay in the longitudinal distribution of biofilm.

Mizugakiibacter and Azospira anaerobic fermentation bacterium dominate the FSC organisms indicating the dominant mechanism on the biofilm is sludge decay.

The floating spherical carriers with compound of the polyurethane and two fiber balls can effectively blocking suspended sludge, improving Biofilm formation efficiency significantly.

关键词： In situ sludge reduction Biofilm Composite floating spherical carriers Microbial community SBBR

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encapsulating M(Co, Fe)-Ni alloy for electrochemical production of syngas with potential-independent CO/H

《化学科学与工程前沿（英文）》 2022年第16卷第4期页码 498-510 doi: 10.1007/s11705-021-2082-6

摘要： The electrochemical conversion of CO₂-H₂O into CO-H₂ using renewable energy is a promising technique for clean syngas production. Low-cost electrocatalysts to produce tunable syngas with a potential-independent CO/H₂ ratio are highly desired. Herein, a series of N-doped carbon nanotubes encapsulating binary alloy nanoparticles (M_xNi-NCNT, M= Fe, Co) were successfully fabricated through the co-pyrolysis of melamine and metal precursors. The M_xNi-NCNT samples exhibited bamboo-like nanotubular structures with a large specific surface area and high degree of graphitization. Their electrocatalytic performance for syngas production can be tuned by changing the alloy compositions and modifying the electronic structure of the carbon nanotube through the encapsulated metal nanoparticles. Consequently, syngas with a wide range of CO/H₂ ratios, from 0.5:1 to 3.4:1, can be produced on M_xNi-NCNT. More importantly, stable CO/H₂ ratios of 2:1 and 1.5:1, corresponding to the ratio to produce biofuels by syngas fermentation, could be realized on Co₁Ni-NCNT and Co₂Ni-NCNT, respectively, over a potential window of –0.8 to –1.2 V versus the reversible hydrogen electrode. Our work provides an approach to develop low-cost and potential-independent electrocatalysts to effectively produce syngas with an adjustable CO/H₂ ratio from electrochemical CO₂ reduction.

关键词： electrochemical reduction of CO₂ syngas N-doped carbon nanotubes encapsulated alloy nanoparticles CO/H₂ ratio

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基于实时CT扫描技术的CO₂和N₂交替注入条件下煤吸附膨胀和解吸收缩规律研究 Article

张广磊, P.G. Ranjith, Herbert E. Huppert

《工程（英文）》 2022年第18卷第11期页码 88-95 doi: 10.1016/j.eng.2022.03.010

摘要：

深部煤层是分布最广泛的适宜二氧化碳（CO₂）地质封存的地层之一，且通常位于大型CO₂排放源附近。将CO₂注入到煤层中具有巨大的CO₂封存潜力，同时可以提高煤层气的采收率（CO₂-ECBM）。本文采用原位同步辐射X射线显微CT扫描技术，首次在原位条件下直接证明了注入氮气（N₂）可以置换解吸CO₂并减小因CO₂吸附引起的煤基质膨胀研究结果表明，煤层中注入经过简单处理的烟道气（主要成分为N₂和CO₂），是技术上可行的CO₂-ECBM 替代方案。其次，N₂的存在可以使煤层保持较高的渗透率，实现长期CO₂注入封存和煤层气增产。

关键词： CCS CO₂-ECBM 碳中和 X 射线成像煤渗透率

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Al₂O₃ and CeO₂-promoted MgO sorbents for CO₂ capture at moderate

Huimei Yu, Xiaoxing Wang, Zhu Shu, Mamoru Fujii, Chunshan Song

《化学科学与工程前沿（英文）》 2018年第12卷第1期页码 83-93 doi: 10.1007/s11705-017-1691-6

摘要： A series of Al O and CeO modified MgO sorbents was prepared and studied for CO sorption at moderate temperatures. The CO sorption capacity of MgO was enhanced with the addition of either Al O or CeO . Over Al O -MgO sorbents, the best capacity of 24.6 mg-CO /g-sorbent was attained at 100 °C, which was 61% higher than that of MgO (15.3 mg-CO /g-sorbent). The highest capacity of 35.3 mg-CO /g-sorbent was obtained over the CeO -MgO sorbents at the optimal temperature of 200 °C. Combining with the characterization results, we conclude that the promotion effect on CO sorption with the addition of Al O and CeO can be attributed to the increased surface area with reduced MgO crystallite size. Moreover, the addition of CeO increased the basicity of MgO phase, resulting in more increase in the CO capacity than Al O promoter. Both the Al O -MgO and CeO -MgO sorbents exhibited better cyclic stability than MgO over the course of fifteen CO sorption-desorption cycles. Compared to Al O , CeO is more effective for promoting the CO capacity of MgO. To enhance the CO capacity of MgO sorbent, increasing the basicity is more effective than the increase in the surface area.

关键词： CO₂ capture MgO sorbents Al₂O₃ CeO₂ flue gas