ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
·
2014
·Vol. 39
·期 10
·7355-7361
·
IF 0.367
Hu Zhide,Yan Hua,Yang Jianjian,Wang Xuemei,Yu Rongsheng
Magnetorheological (MR) fluid has been widely used in many engineering field because of its unique magnetorheological effect. However, the poor lubrication of it needs to be considered seriously. Otherwise, the engineering applicability of MR fluid may be hindered. The friction property of several MR fluids based on different components was investigated on a modified four-ball tester. Two kinds of experimental conditions were designed, namely off-field and steady magnetic field. The results show that tribological properties of MR fluid are mainly decided by base oils. The friction properties of mineral oil-based MR fluid are better than that based on synthetic oil. The effect of two kinds of thixotropic agents on the tribological properties of MR fluid is exact opposite with and without magnetic field. Silica is superior to clay without magnetic field. Under steady magnetic field condition, the friction coefficient of MR fluid is over three times larger than that of MR fluid in off-field. The effect of base oil on the friction property is similar to that without magnetic field. But clay is better than silica due to the effect of magnetic field.
研究领域:
材料科学
·
流变学
·
摩擦学
·
功能材料
·
智能材料
✓ 已验证
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2021
·
IF 6.475
Wei Jia,Zibian Fan,An Du,Lin Shi
Ageing is a time-consuming step in Baijiu manufacture, stimulating an urgent requirement of optimization. Variation of artificial aged Feng-flavor Baijiu by inhomogeneous alternating magnetic field was investigated through quantitative foodomics combined with confirmed ultra high performance liquid chromatography quadrupole-orbitaltrap high resolution mass spectrometry (UHPLC-Q-Orbitrap). A total of 153 substances were identified with significant variables (p < 0.05, VIP > 1) and 16 metabolic pathways related to Feng-flavor Baijiu functions were obtained. The method showed good accuracy with recovery values between 80.4% and 117.4% and precision lower than 9.8% for all characteristic substances. Limit of detection (LOD) was ranging between 1.6 and 10.0 μg/L with R 2 ≥ 0.99. Factor analysis demonstrated that ageing degree of magnetized samples increased with rise of magnetic field intensity and the maximum effect was equivalent to 12.81 years of natural ageing. The results of stoichiometric analysis revealed that regulation of magnetic field on proportion in Baijiu was mainly performed through entropy and the hydrogen bond strength of Baijiu molecules. Sensory evaluation illustrated that score of Baijiu samples reached the highest at 150 mT, demonstrating that magnetic field treatment can be considered as an optimized ageing means for Feng-flavor Baijiu.
研究领域:
食品科学
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
FUEL
·
2021
·
IF 6.609
Yongji Wu,Tianqi Tang,Lei Shi,Yurong He
Natural gas hydrate technologies have been perceived as promising methods of natural gas storage and transportation. Rapid achievement of high gas storage is the primary objective of hydrate applications. In this work, Fe 3 O 4 nanoparticles were synthesized and surface-modified by sodium oleate (SO) and sodium dodecyl sulfate (SDS) bilayer molecules (hereafter SDS&SO@Fe 3 O 4 ). The prepared SDS&SO@Fe 3 O 4 nanosuspensions exhibited sufficient water dispersion stability and were utilized as promoters for hydrate-based methane storage. The composite promoter exerted apparent higher methane storage capacity and hydrate formation rate than pure SDS solution. The maximum storage capacity with SDS&SO@Fe 3 O 4 was 156.5 v/v and the whole hydration process could be completed in only 32 min. Moreover, magnetic fields were successfully introduced to the reaction system, which exhibited a further promotion to hydrate formation due to the regular arrangement of SDS&SO@Fe 3 O 4 . In the presence of a magnetic field, the major superiority was that induction period together with the total hydration period were prominently shortened and the induction time was negligible when the magnetic intensity exceeded 193 mT. In summary, the bilayer surfactant-coated Fe 3 O 4 nanoparticles developed in this study led to substantial improvements in methane hydrate formation kinetics and therefore have great potential in industrial applications involving hydrate-based energy storage.
研究领域:
化学工程
·
能源技术
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Jie Yang,Gao Song,Ling Zhou,Xinyue Wang,Lijun You,Jumei Li
In this study, we successfully constructed Ag/TiO 2 core-shell nanoparticles through an easy wet chemistry method for SERS study. Compared to Ag cores, the Ag/TiO 2 core-shell nanoparticles presented higher SERS sensitivity, owing to a synergistic SERS enhancement arising from electromagnetic field effect of Ag cores and chemical enhancement of TiO 2 shells. Furthermore, uniform TiO 2 shells were able to effectively protect the internal Ag cores against destruction in external environment and thus storage stability of Ag/TiO 2 nanoparticles was prominently improved. The as prepared Ag/TiO 2 core-shell nanoparticles were applied to quantitatively sense tetramethylthiuram disulfide (TMTD) in solution using a portable Raman spectrometer. The results showed that the SERS intensity of 563 cm −1 assigned to S-S stretching mode had a good linear relationship with the concentration of TMTD with the correlation coefficient (R 2 ) of as high as 0.99 and the detection limit of as low as 1.15 × 10 −10 M. Consequently, the prepared Ag/TiO 2 nanoparticles present specially advantage of quantifying S-S groups by SERS, because the TiO 2 shell could act as a spacer between Ag cores and TMTD molecules and keep the S-S bonds intact.
研究领域:
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Applied Spectroscopy
·
2024
·Vol. 91
·期 4
·903-911
·
IF 0.8
Zheng Zhiheng,Zhang Fan,Liu Yankun,Wang Zhiwu,Pei Yuan,Wu Zhengang,Li Bo,Wei Yingna,Chen Ying,Wei Hengyong,Li Jingwu
TiN–Ag@Ag composite substrates were prepared via ammonia reduction nitridation followed by electrochemical deposition. Fabricated TiN–Ag@Ag substrates were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and ultraviolet-visible spectrophotometry. The surface-enhanced Raman spectroscopy activity of these substrates was evaluated using ibuprofen as the probe molecule. The size of the Ag particles prepared via electrochemical deposition was approximately 1 μm, and Ag nanoparticles with an average particle size of 100 nm were uniformly distributed on the surface of TiN–Ag films. The Raman signal of ibuprofen was significantly enhanced, and the minimum detection concentration of ibuprofen was 10 –5 M. The mechanism by which the TiN–Ag@Ag composite substrate enhanced the Raman signals was analyzed using ultraviolet photoelectron spectroscopy and density functional theory implemented in the Gaussian software. Overall, charge transfer and the local electromagnetic field effect enhanced the Raman signals of ibuprofen.
研究领域:
材料科学
·
分析化学
·
纳米技术
·
药物分析
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Jiafeng He,Xian Li,Jumei Li
Here, we demonstrate a reliable surface-enhanced Raman scattering (SERS) substrate composed of graphene oxide (GO) nanosheets and Ag nanocubes for sensitive detection of varied organic contaminants , malachite green, methylene blue and crystal violet by a portable Raman spectrometer with the limits of detection (LODs) of 10 −9 , 10 −10 and 10 −9 M, respectively, owing to a synergistic SERS enhancement arising from electromagnetic field effect of Ag nanocubes and chemical enhancement of GO sheets. The SERS substrates also present highly uniform signal over substrates and low relative standard deviations of 6.53 %, 6.16 % and 6.70 %, respectively are obtained on each sample, which is attribute to the extremely uniform size of Ag nanocubes as well as the consistent distribution of Ag nanocubes on GO sheets. Moreover, the SERS substrate is capable of label-free detection of more complex organic pesticides such as tetramethylthiuram disulfide and diquat dibromide with the LOD of 10 −8 M, which is below the safety levels regulated by United States Environmental Protection Agency. Consequently, the Ag nanocubes/GO composites are promising as efficient SERS platforms for reliable and highly sensitive monitoring of food safety and environmental pollution .
研究领域:
纳米技术
·
分析化学
·
环境科学
·
材料科学
·
食品安全
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）