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Selective catalytic reduction of NO

Pavlo I. Kyriienko

《化学科学与工程前沿（英文）》 2020年 第14卷 第4期   页码 471-491 doi: 10.1007/s11705-019-1847-7

摘要： Research results regarding selective catalytic reduction (SCR) of NO with ethanol and other C oxygenates as reductants over silver-alumina catalysts are summarized. The aspects of the process mechanism, nature of active sites, role of alumina and silver (especially in the formation of bifunctional active sites), effects of reductants and reaction conditions are discussed. It has been determined that key stages of the process include formation of reactive enolic species, their interaction with NO and formation of nitroorganic compounds which transform to NCO species and further to N . The results obtained over various silver-alumina catalysts demonstrate the perspectives of their application for reducing the level of nitrogen oxides in engine emissions, including in the presence of water vapor and sulfur oxides. Ways to improve the catalysts for the SCR of NO with C oxygenates are outlined.

关键词： SCR     nitrogen oxides     silver-alumina catalyst     silver species     ethanol     oxygenates    

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Sub-cytotoxic concentrations of ionic silver promote the proliferation of human keratinocytes by inducingthe production of reactive oxygen species

null

《医学前沿（英文）》 2018年 第12卷 第3期   页码 289-300 doi: 10.1007/s11684-017-0550-7

摘要：

Silver-containing preparations are widely used in the management of skin wounds, but the effects of silver ions on skin wound healing remain poorly understood. This study investigated the effects of silver ions (Ag+) on the proliferation of human skin keratinocytes (HaCaT) and the production of intracellular reactive oxygen species (ROS). After treating HaCaT cells with Ag+and/or the active oxygen scavenger N-acetyl cysteine (NAC), cell proliferation and intracellular ROS generation were assessed using CCK-8 reagent and DCFH-DA fluorescent probe, respectively. In addition, 5-bromo-2-deoxyUridine (BrdU) incorporation assays, cell cycle flow cytometry, and proliferating cell nuclear antigen (PCNA) immunocytochemistry were conducted to further evaluate the effects of sub-cytotoxic Ag+ concentrations on HaCaT cells. The proliferation of HaCaT cells was promoted in the presence of 10−6 and 10−5 mol/L Ag+ at 24, 48, and 72 h. Intracellular ROS generation also significantly increased for 5–60 min after exposure to Ag+. The number of BrdU-positive cells and the presence of PCNA in HaCaT cells increased 48 h after the addition of 10−6 and 10−5 mol/L Ag+, with 10−5 mol/L Ag+ markedly increasing the cell proliferation index. These effects of sub-cytotoxic Ag+ concentrations were repressed by 5 mmol/L NAC. Our results suggest that sub-cytotoxic Ag+ concentrations promote the proliferation of human keratinocytes and might be associated with a moderate increase in intracellular ROS levels. This study provides important experimental evidence for developing novel silver-based wound agents or dressings with few or no cytotoxicity.

关键词： ionic silver     human keratinocyte     cell proliferation     reactive oxygen species     active oxygen scavenger     NAC    

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Influence of extracellular polymeric substances from activated sludge on the aggregation kinetics of silverand silver sulfide nanoparticles

《环境科学与工程前沿（英文）》 2022年 第16卷 第2期 doi: 10.1007/s11783-021-1450-2

摘要：

• The NPs aggregation in the electrolyte solution is consistent with the DLVO theory.

关键词： Silver nanoparticles     Silver sulfide nanoparticles     Extracellular polymeric substances     Aggregation kinetics     Influence mechanisms    

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Size-controlled green synthesis of silver nanoparticles assisted by L-cysteine

Wenchao Zhang,Lin Zhang,Yan Sun

《化学科学与工程前沿（英文）》 2015年 第9卷 第4期   页码 494-500 doi: 10.1007/s11705-015-1527-1

摘要： A green and size-controlled synthesis of silver nanoparticles (Ag NPs) in aqueous solution with the assistance of L-cysteine is presented. The size of Ag NPs decreases with the increase of L-cysteine concentration, and thus can be controlled by adjusting L-cysteine concentration. TEM analysis shows that Ag NPs with an average size of 3 nm can be produced in the presence of 1.0 mmol/L L-cysteine, about one sixth of the size of Ag NPs obtained in the absence of L-cysteine (17 nm). The as-synthesized silver colloidal solution is stable and can be stored at room temperature for at least two months without any precipitation. This L-cysteine assisted method is simple, feasible and efficient, and would facilitate the production and application of Ag NPs.

关键词： nanoparticles     silver     L-cysteine     size distribution     synthesis    

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Preparation and characterization of polyimide/silica/silver composite films

JIANG Lizhong, WU Dezhen, LUO Ning, WU Zhanpeng, MOU Nanxiang

《化学科学与工程前沿（英文）》 2008年 第2卷 第3期   页码 291-295 doi: 10.1007/s11705-008-0059-3

摘要： Polyimide/silica/silver hybrid films were prepared by the sol-gel method combined with single-stage self-metallization technique. The structure of polyimide films in the thermal curing process and the influence of silica content on the migration and aggregation of silver particles to the surface of hybrid films were investigated. The hybrid films were characterized by transmission electron microscopy, dynamic mechanical thermal analysis, Fourier transform infrared spectroscopy, ultraviolet visible spectroscopy and mechanical measurements. The results indicated that there was no degradation of the polyimide matrix after the formation of silica and silver particles. Silica acted as the nucleus for the silver particles. With increasing silica content, more and more silver particles were kept in the hybrid films instead of being migrated onto the surface of the hybrid films and the reflections of hybrid films decreased gradually.

关键词： single-stage self-metallization     spectroscopy     transmission     Polyimide/silica/silver     ultraviolet visible    

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The formation and catalytic activity of silver nanoparticles in aqueous polyacrylate solutions

Jie Wang, Jianjia Liu, Xuhong Guo, Liang Yan, Stephen F. Lincoln

《化学科学与工程前沿（英文）》 2016年 第10卷 第3期   页码 432-439 doi: 10.1007/s11705-016-1584-0

摘要： Silver nanoparticles (AgNPs) have been synthesized in the presence of polyacrylate through the reduction of silver nitrate by sodium borohydride in aqueous solution. The AgNO and polyacrylate carboxylate group concentrations were kept constant at 2.0 × 10 and 1.0 × 10 mol?L , respectively, while the ratio of [NaBH ]/[AgNO ] was varied from 1 to 100. The ultra-violet-visible plasmon resonance spectra of these solutions were found to vary with time prior to stabilizing after 27 d, consistent with changes of AgNP size and distribution within the polyacrylate ensemble occurring. These observations, together with transmission electron microscopic results, show this rearrangement to be greatest among the samples at the lower ratios of [NaBH ]/[AgNO ] used in the preparation, whereas those at the higher ratios showed a more even distribution of smaller AgNP. All ten of the AgNP samples, upon a one thousand-fold dilution, catalyze the reduction of 4-nitrophenol to 4-aminophenol in the temperature range 283.2–303.2 K with a substantial induction time being observed at the lower temperatures.

关键词： silver nanoparticles     polyacrylates     catalysis     mechanism     sodium borohydride    

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Preparation and performance of soft actuator based on IPMC with silver electrodes

Qi CHEN, Ke XIONG, Kan BIAN, Ning JIN, Bangfeng WANG,

《机械工程前沿（英文）》 2009年 第4卷 第4期   页码 436-440 doi: 10.1007/s11465-009-0054-5

摘要： The surface electrodes of traditional ionic polymer-metal composites (IPMC) are made of platinum. To reduce the production cost, nonprecious metals such as silver is proposed. A new approach of electroless silver plating based on chemical deposition method is adopted, getting two types of IPMCs, Pt-Ag IPMC, and Ag-Ag IPMC. The microscopic analysis, driving abilities tests, and their surface-electrode resistance analysis show that Ag and Pt particles penetrate inside Nafion membrane with gradient distribution throughout the membrane. The maximum electro-active bending deformation angles of the specimens, which are obtained under the same specimen dimension and constrains, are about 60° for Pt-Pt IPMC and Pt-Ag IPMC and 90° for the Ag-Ag IPMC, respectively, corresponding to the driving voltage of 3 V, 4 V, and 1.5 V. The surface-electrode resistance of Ag-Ag IPMC is the lowest and the most stable, which shows that the proposed approach is valid. The experiments show that the IPMC technology based on the silver electrode is feasible.

关键词： ionic polymer-metal composites (IPMC)     Nafion     intelligent material     soft actuators     electroless silver plating    

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Controlled synthesis of uniform silver nanowires with high aspect ratios in aqueous solutions of gemini

XU Jian, LIU Weijun, LIU Honglai, HU Ying

《化学科学与工程前沿（英文）》 2007年 第1卷 第3期   页码 221-227 doi: 10.1007/s11705-007-0040-6

摘要： A simple solution-phase approach has been demonstrated for the large-scale synthesis of silver nanowires with diameters in the range of 15 25 nm, and lengths usually in the range of tens of micrometers. In the presence of gemini surfactant 1,3-bis(cetyldimethylammonium) propane dibromide (16-3-16), the growth of silver could be directed into a highly anisotropic mode to form uniform nanowires with aspect ratios up to about 2,000. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), X-ray powder diffraction (XRD), electron diffraction (ED), and UV-vis absorption spectroscopy, were used to characterize the as-prepared silver nanowires, indicating the formation of a highly pure phase, good crystallinity, as well as a uniform diameter.

关键词： solution-phase     photoelectron spectroscopy     16-3-16     surfactant     transmission    

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VITHM1 mediated green synthesis of silver nanoparticles: Mechanism and biological applications

Mani Abirami, Krishnan Kannabiran

《化学科学与工程前沿（英文）》 2016年 第10卷 第4期   页码 542-551 doi: 10.1007/s11705-016-1599-6

摘要： We present the microbial green synthesis of silver nanoparticles (NPs) by VITHM1 strain (MTCC No. 12465). The secondary metabolites in the cell free supernatant of this bacterium when incubated with 1 mmol/L AgNO , mediated the biological synthesis of AgNPs. The synthesized AgNPs were characterized by UV-visible spectrum, X-ray diffraction (XRD), atomic force microscope, scanning electron microscopy equipped with energy dispersive spectroscopy, transmission electron microscopy, FT-IR spectroscopy, dynamic light scattering and zeta potential. They were highly stable and, spherical in shape with the average size of 30?50 nm. The secondary metabolites involved in the formation of AgNPs were identified gas chromatography-mass spectrography. The 3D structure of the unit cell of the synthesized AgNPs was determined using XRD data base. The synthesized AgNPs exhibited significant antibacterial activity against tested bacterial pathogens, and did not show haemolysis on human red blood cells. This green synthesis could provide a new platform to explore and use AgNPs as antibacterial therapeutic agents.

关键词： Streptomyces ghanaensis VITHM1     nanoparticles     3D structure     antibacterial activity    

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THE 4C APPROACH AS A WAY TO UNDERSTAND SPECIES INTERACTIONS DETERMINING INTERCROPPING PRODUCTIVITY

《农业科学与工程前沿（英文）》 2021年 第8卷 第3期   页码 387-399 doi: 10.15302/J-FASE-2021414

摘要：

Modern agriculture needs to develop transition pathways toward agroecological, resilient and sustainable farming systems. One key pathway for such agroecological intensification is the diversification of cropping systems using intercropping and notably cereal-grain legume mixtures. Such mixtures or intercrops have the potential to increase and stabilize yields and improve cereal grain protein concentration in comparison to sole crops. Species mixtures are complex and the 4C approach is both a pedagogical and scientific way to represent the combination of four joint effects of Competition, Complementarity, Cooperation, and Compensation as processes or effects occurring simultaneously and dynamically between species over the whole cropping cycle. Competition is when plants have fairly similar requirements for abiotic resources in space and time, the result of all processes that occur when one species has a greater ability to use limiting resources (e.g., nutrients, water, space, light) than others. Complementarity is when plants grown together have different requirements for abiotic resources in space, time or form. Cooperation is when the modification of the environment by one species is beneficial to the other(s). Compensation is when the failure of one species is compensated by the other(s) because they differ in their sensitivity to abiotic stress. The 4C approach allows to assess the performance of arable intercropping versus classical sole cropping through understanding the use of abiotic resources.

 

关键词： compensation     competition     complementarity     cooperation     interspecific interactions     land equivalent ratio     light     nutrients     species mixtures     water    

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Preparation and properties of a silver particle-coated and 1-dodecanethiol-modified superhydrophobic

《化学科学与工程前沿（英文）》 2022年 第16卷 第8期   页码 1237-1246 doi: 10.1007/s11705-022-2140-8

摘要： A Ag particle-coated and 1-dodecanethiol-modified melamine sponge (Ag-DDT-MS) was prepared through surface roughness by coating silver particles and subsequent grafting of a hydrophobic long hydrocarbon chain. Superhydrophobic and 3D porous Ag-DDT-MS was characterized by Fourier transform infrared spectroscopy, scanning electron microscope, energy-dispersive X-ray spectroscopy, and X-ray diffraction. The water contact angle of Ag-DDT-MS reached 159.2°. Ag-DDT-MS exhibited excellent absorption capacity for high viscous oils and organic solvents, ranging from 42.8 to 105.2 g∙g−1. The absorbed oils can be easily collected by the mechanical pressing process, and the oil recovery rate was satisfactory, more than 90% after 20 recycles. Ag-DDT-MS material also demonstrated good stability and excellent compression-recovery ability, keeping 88.6% of the initial height after ten compression-release cycles.

关键词： melamine sponge     oil-absorbing material     hydrophobic     oil-water separation     oil absorption capacity    

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COMPARING PERFORMANCE OF CROP SPECIES MIXTURES AND PURE STANDS

《农业科学与工程前沿（英文）》 2021年 第8卷 第3期   页码 481-489 doi: 10.15302/J-FASE-2021413

摘要：

Intercropping is the planned cultivation of species mixtures on agricultural land. Intercropping has many attributes that make it attractive for developing a more sustainable agriculture, such as high yield, high resource use efficiency, lower input requirements, natural suppression of pests, pathogens and weeds, and building a soil with more organic carbon and nitrogen. Information is needed which species combinations perform best under different circumstances and which management is suitable to bring out the best from intercropping in a given production situation. The literature is replete with case studies on intercropping from across the globe, but evidence synthesis is needed to make this information accessible. Meta-analysis requires a careful choice of metric that is appropriate for answering the question at hand, and which lends itself for a robust meta-analysis. This paper reviews some metrics that may be used in the quantitative synthesis of literature data on intercropping.

 

关键词： intercropping     species mixtures     meta-analysis     metrics     indicators    

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Tracking in urban wastewater treatment plants in a cold region: Occurrence, species and infectivity

《环境科学与工程前沿（英文）》 2022年 第16卷 第9期 doi: 10.1007/s11783-022-1533-8

摘要：

• Cryptosporidium in WWTPs in a cold region was investigated in different seasons.

关键词： WWTPs     Cryptosporidium     Occurrence     Species     Infectivity     Low temperature    

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IN VITRO ACTIVITY OF EXTRACTS OF FIVE MEDICINAL PLANT SPECIES ON PLANT PATHOGENIC FUNGI

《农业科学与工程前沿（英文）》 2021年 第8卷 第4期   页码 635-644 doi: 10.15302/J-FASE -2020343

摘要：

The antifungal effectiveness of extracts of five medicinal plant species was determined. The inhibitory activity of extracts of Eucalyptus tereticornis, Xanthium sibiricum, Artemisia argyi, Tupistra chinensis and Pyrola calliantha were evaluated against the mycelial growth of the plant pathogenic fungi Aspergillus niger, Botrytis cinerea, Penicillium digitatum, P. expansum, P. italicumand Rhizopus stolonifer. All plant extracts were prepared at 60°C using solvents (either water, 50% ethanol (v/v), 95% ethanol (v/v), ethyl acetate or petroleum ether). Fungicidal effects of all plants tested were confirmed. Different extracts from the same plant species gave different degrees of inhibition. All aqueous extracts had weak or no activity on all fungi tested. Ethyl acetate and 95% ethanol extracts from T. chinensis rhizomes gave greater inhibition and a broader spectrum inhibition than the other extracts. T. chinensis may have potential as a new natural fungicide and may be used for the preservation of agricultural and forestry products such as fruits and vegetables.

 

关键词： Botrytis cinerea / food preservation / plant diseases / plant pathogenic fungi / Tupistra chinensis    

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bold>Escherichia coli and bacteriophage MS2 in water using a copper and silver

Guiying RAO, Kristen S. BRASTAD, Qianyi ZHANG, Rebecca ROBINSON, Zhen HE, Ying LI

《环境科学与工程前沿（英文）》 2016年 第10卷 第4期 doi: 10.1007/s11783-016-0854-x

摘要： A novel photocatalytic Ag-Cu-TiO nanowire membrane was fabricated. Bacteria and virus disinfection was improved by co-depositing Ag and Cu onto membrane. Synergetic photocatalytic effects and free metal ions of Ag and Cu contribute to disinfection. 7.68 log removal of and 4.02 log removal of bacteriophage MS2 were achieved. Titanium dioxide (TiO ) is a widely used photocatalyst that has been demonstrated for microorganism disinfection in drinking water. In this study, a new material with a novel structure, silver and copper loaded TiO nanowire membrane (Cu-Ag-TiO ) was prepared and evaluated for its efficiency to inactivate and bacteriophage MS2. Enhanced photo-activated bactericidal and virucidal activities were obtained by the Cu-Ag-TiO membrane than by the TiO , Ag-TiO and Cu-TiO membranes under both dark and UV light illumination. The better performance was attributed to the synergies of enhanced membrane photoactivity by loading silver and copper on the membrane and the synergistic effect between the free silver and copper ions in water. At the end of a 30 min test of dead-end filtration under 254 nm UV irradiation, the Cu-Ag-TiO membrane was able to obtain an removal of 7.68 log and bacteriophage MS2 removal of 4.02 log, which have met the US EPA standard. The free metal ions coming off the membrane have concentrations of less than 10 ppb in the water effluent, far below the US EPA maximum contaminant level for silver and copper ions in drinking water. Therefore, the photo-activated disinfection by the Cu-Ag-TiO membrane is a viable technique for meeting drinking water treatment standards of microbiological water purifiers.

关键词： Photo-activated disinfection     Titanium dioxide     Nanowire membrane     Silver     Copper    

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标题 作者 时间 类型 操作

Selective catalytic reduction of NO

Pavlo I. Kyriienko

期刊论文

Sub-cytotoxic concentrations of ionic silver promote the proliferation of human keratinocytes by inducingthe production of reactive oxygen species

null

期刊论文

Influence of extracellular polymeric substances from activated sludge on the aggregation kinetics of silverand silver sulfide nanoparticles

期刊论文

Size-controlled green synthesis of silver nanoparticles assisted by L-cysteine

Wenchao Zhang,Lin Zhang,Yan Sun

期刊论文

Preparation and characterization of polyimide/silica/silver composite films

JIANG Lizhong, WU Dezhen, LUO Ning, WU Zhanpeng, MOU Nanxiang

期刊论文

The formation and catalytic activity of silver nanoparticles in aqueous polyacrylate solutions

Jie Wang, Jianjia Liu, Xuhong Guo, Liang Yan, Stephen F. Lincoln

期刊论文

Preparation and performance of soft actuator based on IPMC with silver electrodes

Qi CHEN, Ke XIONG, Kan BIAN, Ning JIN, Bangfeng WANG,

期刊论文

Controlled synthesis of uniform silver nanowires with high aspect ratios in aqueous solutions of gemini

XU Jian, LIU Weijun, LIU Honglai, HU Ying

期刊论文

VITHM1 mediated green synthesis of silver nanoparticles: Mechanism and biological applications

Mani Abirami, Krishnan Kannabiran

期刊论文

THE 4C APPROACH AS A WAY TO UNDERSTAND SPECIES INTERACTIONS DETERMINING INTERCROPPING PRODUCTIVITY

期刊论文

Preparation and properties of a silver particle-coated and 1-dodecanethiol-modified superhydrophobic

期刊论文

COMPARING PERFORMANCE OF CROP SPECIES MIXTURES AND PURE STANDS

期刊论文

Tracking in urban wastewater treatment plants in a cold region: Occurrence, species and infectivity

期刊论文

IN VITRO ACTIVITY OF EXTRACTS OF FIVE MEDICINAL PLANT SPECIES ON PLANT PATHOGENIC FUNGI

期刊论文

bold>Escherichia coli and bacteriophage MS2 in water using a copper and silver

Guiying RAO, Kristen S. BRASTAD, Qianyi ZHANG, Rebecca ROBINSON, Zhen HE, Ying LI

期刊论文