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Decomposition of aqueous chlorinated contaminants by UV irradiation with H

Eunsung KAN,Chang-Il KOH,Kyunghyuk LEE,Joonwun KANG

《环境科学与工程前沿（英文）》 2015年第9卷第3期页码 429-435 doi: 10.1007/s11783-014-0677-6

摘要： In the present study, the decomposition rates of carbon tetrachloride (CCl ) and 2,4-dichlorophenol (2,4-DCP) in water by the ultraviolet (UV) light irradiation alone and H O /UV were experimentally investigated. The detailed experimental studies have been conducted for examining treatment capacities of the two different ultraviolet light sources (low and medium pressure Hg arc) in H O /UV processes. The low or medium UV lamp alone resulted in a 60%–90% decomposition of 2,4-DCP while a slight addition of H O resulted in a drastic enhancement of the 2,4-DCP decomposition rate. The decomposition rate of 2,4-DCP with the medium pressure UV lamp alone was about 3–6 times greater than the low pressure UV lamp alone. In the direct photolysis of aqueous CCl , the medium pressure UV lamp had advantage over the low pressure UV lamp because the molar extinction coefficient of CCl at shorter wavelength (210–220 nm) is about 20 to 50 times higher than that at 254 nm. However, adding H O to the medium pressure UV lamp system rendered a negative oxidation rate because H O acted as a UV absorber being competitive with CCl due to negligible reaction between CCl and OH radicals. The results from the present study indicated significant influence of the photochemical properties of the target contaminants on the photochemical treatment characteristics for designing cost-effective UV-based degradation of toxic contaminants.

关键词： H₂O₂/ultraviolet (UV) light advanced oxidation UV light irradiation chlorinated contaminants photochemical treatment characteristics

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Enhanced triallyl isocyanurate (TAIC) degradation through application of an O

Yapeng Song, Hui Gong, Jianbing Wang, Fengmin Chang, Kaijun Wang

《环境科学与工程前沿（英文）》 2020年第14卷第4期 doi: 10.1007/s11783-020-1243-z

摘要： Abstract • UV/O3 process had higher TAIC mineralization rate than O3 process. • Four possible degradation pathways were proposed during TAIC degradation. • pH impacted oxidation processes with pH of 9 achieving maximum efficiency. • CO32– negatively impacted TAIC degradation while HCO3– not. • Cl– can be radicals scavenger only at high concentration (over 500 mg/L Cl–). Triallyl isocyanurate (TAIC, C12H15N3O3) has featured in wastewater treatment as a refractory organic compound due to the significant production capability and negative environmental impact. TAIC degradation was enhanced when an ozone(O3)/ultraviolet(UV) process was applied compared with the application of an independent O3 process. Although 99% of TAIC could be degraded in 5 min during both processes, the O3/UV process had a 70%mineralization rate that was much higher than that of the independent O3 process (9%) in 30 min. Four possible degradation pathways were proposed based on the organic compounds of intermediate products identified during TAIC degradation through the application of independent O3 and O3/UV processes. pH impacted both the direct and indirect oxidation processes. Acidic and alkaline conditions preferred direct and indirect reactions respectively, with a pH of 9 achieving maximum Total Organic Carbon (TOC) removal. Both CO32– and HCO3– decreased TOC removal, however only CO32– negatively impacted TAIC degradation. Effects of Cl– as a radical scavenger became more marked only at high concentrations (over 500 mg/L Cl–). Particulate and suspended matter could hinder the transmission of ultraviolet light and reduce the production of HO· accordingly.

关键词： Triallyl isocyanurate O₃/UV Advanced oxidation processes (AOP) Degradation pathway

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Kinetics of UV curable alkyl 3-mercaptopropionate-vinyl silizane

SONG Jiale, CHEN Lixin, WANG Yazhou, CHEN Weiwei, WANG Rumin

《化学科学与工程前沿（英文）》 2008年第2卷第4期页码 390-395 doi: 10.1007/s11705-008-0080-6

摘要： Photopolymerization of vinyl-containing liquid silizane preceramic monomers copolymerized with thiol monomers, based on a step-growth radical polymerization mechanism, is a novel, rapid, inexpensive and simple technique for producing preceramic structures from liquid precursors. The kinetics of alkyl 3-mercptopropionate-vinyl silizane under UV irradiation is investigated by using real-time Fourier transform infrared (FT-IR) and photo-differential scanning calorimetry (photo-DSC). The experimental results show preliminarily that: (1) about 80% conversion of vinyl group has been achieved in the presence of a low concentration photoinitiator under UV irradiation; (2) by increasing the functionalities of the thiol group, the peak rate of copolymerization increases and the final conversion of the vinyl group decreases; (3) the copolymerization is primarily a bimolecular radical termination process; (4) the copolymerization is first-order, i.e., its rate is proportional to the vinyl group concentration and independent of the concentration of thiol group.

关键词： step-growth irradiation bimolecular preceramic concentration photoinitiator

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Is atmospheric oxidation capacity better in indicating tropospheric O formation?

《环境科学与工程前沿（英文）》 2022年第16卷第5期 doi: 10.1007/s11783-022-1544-5

摘要：

● This study summarizes and evaluates different approaches that indicate O₃ formation.

关键词： O₃ AOC O₃ formation regime

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Rh₂O₃/hexagonal CePO₄ nanocatalysts for N₂O decomposition

Huan Liu, Zhen Ma

《化学科学与工程前沿（英文）》 2017年第11卷第4期页码 586-593 doi: 10.1007/s11705-017-1659-6

摘要： Hexagonal CePO nanorods were prepared by a precipitation method and hexagonal CePO nanowires were prepared by hydrothermal synthesis at 150 °C. Rh(NO ) was then used as a precursor for the impregnation of Rh O onto these CePO materials. The Rh O supported on the CePO nanowires was much more active for the catalytic decomposition of N O than the Rh O supported on CePO nanorods. The stability of both catalysts as a function of time on stream was studied and the influence of the co-feed (CO , O , H O or O /H O) on the N O decomposition was also investigated. The samples were characterized by N adsorption-desorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron microscopy, hydrogen temperature-programmed reduction, oxygen temperature-programmed desorption, and CO temperature-programmed desorption in order to correlate the physicochemical and catalytic properties.

关键词： Rh₂O₃ CePO₄ N₂O decomposition

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Al₂O₃-M_xO_y硬面陶瓷涂层的喷焊制备及性能研究

王飚,王宇栋,李慧玲,张自华

《中国工程科学》 2002年第4卷第9期页码 75-80

摘要：

在碳钢母材上，用氧乙炔焰喷焊镍包铝合金粉末制取预涂层，喷焊50% Al₂O₃+50% Ni的复合粉末制取过渡层，用等离子喷焊Al₂O₃ - M_xO_y复合粉末制取最终涂层。

关键词： Al₂O₃-M_xO_y 涂层等离子抗腐蚀抗磨损

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含稀释剂的Al-Cr₂O₃体系燃烧合成反应热力学分析与反应模型

张衍诚,潘冶,张传

《中国工程科学》 2004年第6卷第6期页码 63-67

摘要：

对含稀释剂Al203和Cr203的Al-Cr203体系燃烧合成反应进行了热力学计算与分析，讨论了起始反应温度T0、稀释剂Al2O3和Cr2O3的含量对绝热反应温度7^的影响，并得出T<

关键词：金属陶瓷燃烧合成 Al-Cr203体系热力学反应模型

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On the monolayer dispersion behavior of Co₃O₄ on HZSM-5 support: designing applicable

《化学科学与工程前沿（英文）》 2023年第17卷第11期页码 1741-1754 doi: 10.1007/s11705-023-2332-x

摘要： Based on monolayer dispersion theory, Co₃O₄/ZSM-5 catalysts with different loadings have been prepared for selective catalytic reduction of nitrogen oxides by ammonia. Co₃O₄ can spontaneously disperse on HZSM-5 support with a monolayer dispersion threshold of 0.061 mmol 100 m^–2, equaling to a weight percentage around 4.5%. It has been revealed that the quantities of surface active oxygen (O₂^–) and acid sites are crucial for the reaction, which can adsorb and activate NO_x and NH₃ reactants effectively. Below the monolayer dispersion threshold, Co₃O₄ is finely dispersed as sub-monolayers or monolayers and in an amorphous state, which is favorable to generate the two kinds of active sites, hence promoting the performance of ammonia selective catalytic reduction of nitrogen oxide. However, the formation of crystalline Co₃O₄ above the capacity is harmful to the reaction performance. 4% Co₃O₄/ZSM-5, the catalyst close to the monolayer dispersion capacity, possesses the most abundant active O₂^– species and acidic sites, thereby demonstrating the best reaction performance in all the samples. It is proposed the optimal Co₃O₄/ZSM-5 catalyst can be prepared by loading the capacity amount of Co₃O₄ onto HZSM-5 support.

关键词： Co₃O₄/ZSM-5 NO_x-SCR by NH₃ monolayer dispersion threshold effect surface acid sites surface active O₂^– anions

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The stabilization effect of Al₂O₃ on unconventional Pb/SiO₂ catalyst

《化学科学与工程前沿（英文）》 2023年第17卷第10期页码 1423-1429 doi: 10.1007/s11705-023-2315-y

摘要： Similar to Sn, Pb located at the same group (IVA) in the periodic table of elements, can also catalyze propane dehydrogenation to propene, while a fast deactivation can be observed. To enhance the stability, the traditional carrier Al₂O₃ with a small amount, was introduced into Pb/SiO₂ catalyst in this study. It has been proved that Al₂O₃ can inhibit the reduction of PbO, and weaken the agglomeration and loss of Pb species due to its enhanced interaction with Pb species. As a result, 3Al15Pb/SiO₂ catalyst exhibits a much higher stability up to more than 150 h. In addition, a simple schematic diagram of the change of surface species on the catalyst surface after Al₂O₃ addition was also proposed.

关键词： Pb/SiO₂ Al₂O₃ propane dehydrogenation propene stability

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Pd/Fe3O4 supported on bio-waste derived cellulosic-carbon as a nanocatalyst for C–C coupling and electrocatalytic

《化学科学与工程前沿（英文）》 2022年第16卷第10期页码 1514-1525 doi: 10.1007/s11705-022-2158-y

摘要： The current work describes the synthesis of a new bio-waste derived cellulosic-carbon supported-palladium nanoparticles enriched magnetic nanocatalyst (Pd/Fe₃O₄@C) using a simple multi-step process under aerobic conditions. Under mild reaction conditions, the Pd/Fe₃O₄@C magnetic nanocatalyst demonstrated excellent catalytic activity in the Hiyama cross-coupling reaction for a variety of substrates. Also, the Pd/Fe₃O₄@C magnetic nanocatalyst exhibited excellent catalytic activity up to five recycles without significant catalytic activity loss in the Hiyama cross-coupling reaction. Also, we explored the use of Pd/Fe₃O₄@C magnetic nanocatalyst as an electrocatalyst for hydrogen evolution reaction. Interestingly, the Pd/Fe₃O₄@C magnetic nanocatalyst exhibited better electrochemical activity compared to bare carbon and magnetite (Fe₃O₄ nanoparticles) with an overpotential of 293 mV at a current density of 10 mA·cm^–2.

关键词： bio-waste cellulosic-carbon Pd/Fe₃O₄ Hiyama cross-coupling hydrogen evolution reaction recyclability

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Accurate quantification of 3′-terminal 2′-O-methylated small RNAs by utilizing oxidative deep sequencing

《医学前沿（英文）》 2022年第16卷第2期页码 240-250 doi: 10.1007/s11684-021-0909-7

摘要： The continuing discoveries of novel classes of RNA modifications in various organisms have raised the need for improving sensitive, convenient, and reliable methods for quantifying RNA modifications. In particular, a subset of small RNAs, including microRNAs (miRNAs) and Piwi-interacting RNAs (piRNAs), are modified at their 3′-terminal nucleotides via 2′-O-methylation. However, quantifying the levels of these small RNAs is difficult because 2′-O-methylation at the RNA 3′-terminus inhibits the activity of polyadenylate polymerase and T4 RNA ligase. These two enzymes are indispensable for RNA labeling or ligation in conventional miRNA quantification assays. In this study, we profiled 3′-terminal 2′-O-methyl plant miRNAs in the livers of rice-fed mice by oxidative deep sequencing and detected increasing amounts of plant miRNAs with prolonged oxidation treatment. We further compared the efficiency of stem-loop and poly(A)-tailed RT-qPCR in quantifying plant miRNAs in animal tissues and identified stem-loop RT-qPCR as the only suitable approach. Likewise, stem-loop RT-qPCR was superior to poly(A)-tailed RT-qPCR in quantifying 3′-terminal 2′-O-methyl piRNAs in human seminal plasma. In summary, this study established a standard procedure for quantifying the levels of 3′-terminal 2′-O-methyl miRNAs in plants and piRNAs. Accurate measurement of the 3′-terminal 2′-O-methylation of small RNAs has profound implications for understanding their pathophysiologic roles in biological systems.

关键词： small RNAs 2′-O-methylation sequencing RT-qPCR

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DNAN的高级氧化过程研究 Article

苏海磊, Christos Christodoulatos, Benjamin Smolinski, Per Arienti, Greg O´Connor, 孟晓光

《工程（英文）》 2019年第5卷第5期页码 849-854 doi: 10.1016/j.eng.2019.08.003

摘要：结果表明，DNAN易于被UV/H₂O₂氧化降解。当H₂O₂剂量为1500 ppm且初始pH为7时，3 h内DNAN浓度从250 ppm降到1 ppm以内；但3 h内总有机碳（TOC）和总碳（TC）浓度从100UV/H₂O₂氧化过程中，生成的CO₂释放到空气中，因为溶液pH迅速降低到3左右。9 h的UV/H₂O₂处理后，DNAN中的N绝大多数转化为硝态氮。研究表明，UV/H₂O₂氧化是处理DNAN废水的有效技术。

关键词： 2 4-二硝基茴香醚高级氧化技术废水处理光催化

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Feasibility study of plasma sprayed Al₂O₃ coatings as diffusion barrier on CFC

Kirsten BOBZIN, Lidong ZHAO, Nils KOPP, Thomas WARDA

《机械工程前沿（英文）》 2012年第7卷第4期页码 371-375 doi: 10.1007/s11465-012-0339-y

摘要：

Carbon fibre reinforced carbon (CFC) materials are increasingly applied as sample carriers in modern furnaces. Only their tendency to react with different metals at high temperatures by C-diffusion is a disadvantage, which can be solved by application of diffusion barriers. Within this study the feasibility of plasma sprayed Al₂O₃ coatings as diffusion barrier was studied. Al₂O₃ coatings were prepared by air plasma spraying (APS). The coatings were investigated in terms of their microstructure, bonding to CFC substrates and thermal stability. The results showed that Al₂O₃ could be well deposited onto CFC substrates. The coatings had a good bonding and thermal shock behavior at 1060°C. At higher temperature of 1270°C, crack network formed within the coating, showing that the plasma sprayed Al₂O₃ coatings are limited regarding to their application temperatures as diffusion barrier on CFC components.

关键词： diffusion barrier coatings CFC plasma spraying microstructure Al₂O₃

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Preparation and property characterization of PAA/Fe3O4 nanocomposite

WEI Shanshan, ZHANG Yi, XU Jiarui

《化学科学与工程前沿（英文）》 2007年第1卷第3期页码 233-237 doi: 10.1007/s11705-007-0042-4

摘要： PAA/FeO nanocomposites were prepared by mixing nano-FeOvent. The materials were characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscope (FTIR), thermogravimetry analysis (TGA), dynamic ultra-micro hardness tester (DUMHT) and superconducting quantum interference device (SQUID) magnetometer. Results showed that PAA coordinated with nano-FeO to form a cross-linking structure. The presence of nano-FeO enhanced the thermal stability of the nanocomposite. The elasticity and hardness of the nanocomposite increased, and the indentation depth reduced with the increase of FeO content in the composites. The nanocomposites showed superparamagnetic properties at 300 K.

关键词： magnetometer superparamagnetic ultra-micro thermogravimetry transmission

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Ultrasound-assisted co-precipitation synthesis of mesoporous Co3O4–CeO2 composite oxides for highly selective

《化学科学与工程前沿（英文）》 2022年第16卷第8期页码 1211-1223 doi: 10.1007/s11705-022-2145-3

摘要： The one-step highly selective oxidation of cyclohexane into cyclohexanone and cyclohexanol as the essential intermediates of nylon-6 and nylon-66 is considerably challenging. Therefore, an efficient and low-cost catalyst must be urgently developed to improve the efficiency of this process. In this study, a Co₃O₄–CeO₂ composite oxide catalyst was successfully prepared through ultrasound-assisted co-precipitation. This catalyst exhibited a higher selectivity to KA-oil, which was benefited from the synergistic effects between Co³⁺/Co²⁺ and Ce⁴⁺/Ce³⁺ redox pairs, than bulk CeO₂ and/or Co₃O₄. Under the optimum reaction conditions, 89.6% selectivity to KA-oil with a cyclohexane conversion of 5.8% was achieved over Co₃O₄–CeO₂. Its catalytic performance remained unchanged after five runs. Using the synergistic effects between the redox pairs of different transition metals, this study provides a feasible strategy to design high-performance catalysts for the selective oxidation of alkanes.

关键词： Co₃O₄–CeO₂ composite oxides cyclohexanone cyclohexanol ultrasonic-assisted co-precipitation selective oxidation solvent-free