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China Petroleum Processing & Petrochemical Technology 2016年第2期18卷 100-107页

作者： Du Pengfei Chen Guoxu Song Shiyuan Zhao Litao Wu Jiang Cheng Peng Yang Xiao Logistical Engineering University

Lanthanum-doped muscovite(MC) composite particles(hereinafter abbreviated as La-MC) were prepared by the mechanical solid-state-chemistry-reaction method, followed by surface modification with oleic acid. The microstructure of materials was characterized by SEM, XRD, EDS and FTIR. Furthermore, the friction-reduction and anti-wear properties of MC and La-MC as lubricant additives in lithium grease were evaluated using a four-ball friction and wear tester. The results showed that La(OH)_3 nanoparticles were coated on the surface of muscovite. Both MC and La-MC can effectively improve the friction-reduction and anti-wear properties of lithium grease and La-MC presents better tribological properties than MC. The excellent tribological properties of La-MC can be attributed to the formation of the adsorbed La-MC film and the chemical reaction film mainly composed of Fe_2O_3 and SiO_2 on the worn surface, as well as the catalysis of lanthanum element during the friction process.

关键词： muscovite composite particles lubricant additives friction-reduction and anti-wear mechanism

Friction and wear performances of borates and lanthanum chloride in water

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Journal of Rare Earths 2008年第4期26卷 590-593页

作者：陈波水方建华王九李嘉娄方 Logistical Engineering University

The antiwear and friction-reducing performances of sodium borate, potassium borate and lanthanum chloride in water were evaluated on a four-ball friction tester. The topographies, element distribution and chemical characteristics of the worn surfaces were investigated by scanning electron microscope （SEM）, energy dispersion of X-ray （EDX） and X-ray photoelectron spectroscope （XPS）. The results indicated that sodium borate, potassium borate and lanthanum chloride increased extreme pressure, antiwear and friction-reducing capacities of water to a certain extent, of which potassium borate was the best candidate. Combination of lanthanum chloride with sodium borate and po- tassium borate respectively further improved antiwear and friction-reducing capacities. Scratches of worn surfaces lubricated with water containing borates and lanthanum chloride were less severe than those lubricated with water containing borates alone. A tribochemical film mainly composed of oxides of lanthanum, boron and iron reduced friction and wear for water lubricant formulated with both borates and lanthanum chloride.

关键词： borate lanthanum chloride water friction wear rare earths

Effect of Magnetic Field on Tribological Properties of Lubricating Oils with and without Tricresyl Phosphate

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China Petroleum Processing & Petrochemical Technology 2016年第3期18卷 119-124页

作者： Jiang Zeqi Fang Jianhua Chen Boshui Zheng Zhe Li Hao Xu Lai Logistical Engineering University Chongqing 401311

Tribological properties of neat 150 SN mineral base oil and the oils doped with different contents of tricresyl phosphate(TCP) under magnetic field or non-magnetic field were evaluated on a four-ball tribotester, on which an external magnetic field was applied. Furthermore, the morphology and the tribochemical characteristics of the worn surfaces were examined with a scanning electron microscope(SEM) and an X-ray photoelectron spectrograph(XPS). The tribological test results showed that the magnetic field improved anti-wear properties but impaired the friction-reducing properties of neat base oil and the TCP-doped oils. The worn surfaces tested in magnetic field were characterized by a slighter wear than those tested in normal condition, especially for the surfaces lubricated with the TCP-doped oils. Furthermore, the results of XPS analysis indicated that tribochemical films on the surfaces tested with TCP-doped oils were mainly composed of ferriccontaining compounds such as Fe_2O_3, Fe_3O_4 and FePO_4. Under the influence of a magnetic field, the atomic concentrations of oxygen and phosphorous in the frictional sub-surfaces were higher than those without magnetic impact. Thus it can be inferred that the improved anti-wear properties and impaired friction-reducing capabilities of lubricating oils with TCP under a magnetic field were related to the diffusion of phosphorus and oxygen into the substrate induced by magnetism.

关键词： magnetic field tricresyl phosphate tribological properties mechanisms

Preparation and tribological properties of lanthanum-doped TiO_2 nanoparticles in rapeseed oil

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Journal of Rare Earths 2013年第6期31卷 589-594页

作者：谷科城陈波水陈勇 Department of Oil Application & Management engineering Logistical Engineering University Department of Barracks Management & Environmental engineering Logistical Engineering University

Oleic acid （denoted as OA） surface-capped lanthanum-doped titanium dioxide composite nanoparticles, abbreviated as OA/La-TiO2, were prepared via sol-gel method in association with surface modification by oleic acid. The microstructure of as-prepared OA/La-TiO2 was characterized by means of X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectrometry, and their thermal stability was evaluated by thermogravimetry and differential scanning calorimetry. Moreover, the tribological properties of OA/La-TiO2 as lubricant additives in rapeseed oil were evaluated with a four-ball friction and wear tester. The morphology as well as elemental composition and chemical characteristics of worn steel surfaces was investigated by scanning electron microscopy, energy dispersive X-ray spectrometry and X-ray photoelectron spectroscopy. Results showed that as-prepared OA/La-TiO2 particles were of spherical shape and had an average diameter of 20 nm. In the meantime, OA/La-TiO2 particles doped with 1.5% （molar ratio; the same hereafter） and 2.5% of lanthanum could markedly improve the anti-wear and friction-reducing capacities of rapeseed oil. This is attributed to the formation of a complex boundary lubrication film mainly composed of the oxides of iron, titanium and lanthanum as well as the formation of an adsorption film of oleic acid on steel sliding surfaces.

关键词： titanium dioxide lanthanum nanoparticle preparation rapeseed oil lubricant additive tribological properties rare earths

Preparation and Tribological Behavior of Hydrophobic Lanthanum Borate Nanosheets in Rapeseed Oil

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China Petroleum Processing & Petrochemical Technology 2016年第2期18卷 92-99页

作者： Gu Kecheng Chen Boshui Xue Ming Wang Jiu Fang Jianhua Wu Jiang Department of Oil Application and Management engineering Logistical Engineering University Department of National Defense Architectural Planning and Environment engineering Logistical Engineering University

Oleic acid-capped lanthanum borate(abbreviated as OA/La BO_3·H_2O) nanosheets were prepared by the hydrothermal method. The microstructures of as-prepared OA/La BO_3·H_2O were characterized by means of SEM, TEM, EDS, FTIR and XRD, respectively. Moreover, the friction and wear properties of OA/La BO_3·H_2O as a lubricant additive in rapeseed oil were evaluated on a four-ball tribotester. The tribochemical characteristics of worn surfaces were investigated by SEM and XPS. The results showed that the hydrophobic OA/La BO_3·H_2O nanosheets exhibited their morphology with a diameter in the range of 100 nm to 300 nm and a thickness of about 25 nm, and displayed excellent dispersing stability in rapeseed oil. In the meantime, the rapeseed oil doped with OA/La BO_3·H_2O nanosheets markedly decreased the friction and wear of steel balls, and the optimal friction-reducing and antiwear ability of rapeseed oil was obtained at an OA/La BO_3·H_2O content of 1.0%. The outstanding tribological performance of OA/La BO_3·H_2O in rapeseed oil was attributed to the formation of a composite boundary lubrication film mainly composed of lubricious tribochemical species of B_2O_3, La_2O_3 and Fe_2O_3, and deposits of OA/La BO_3·H_2O nanosheets as well as the adsorbates of rapeseed oil on rubbed surfaces.

关键词： lanthanum borate nanosheet hydrophobicity friction wear rapeseed oil.

Lubricant Biodegradation Enhancers: Designed Chemistry and Engineered Technology

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China Petroleum Processing & Petrochemical Technology 2015年第3期17卷 102-110页

作者： Chen Boshui Gao Lingyue Fang Jianhua Zhang Nan Wu Jiang Wang Jiu College of Petrochemistry Logistical Engineering University

In recent decades, a growing worldwide trend of developing the biodegradable lubricants has been prevailing to form a specific field of green chemistry and green engineering. Enhancement of biodegradability of unreadily biodegradable petroleum-based lubricants has as such become an urgent must. For over a decade the authors have been focusing on the improvement of biodegradability of unreadily biodegradable lubricants such as petroleum-based lubricating oils and greases. A new idea of lubricant biodegradation enhancer was put forward by the authors with the aim to stimulate the biodegradation of unreadily biodegradable lubricants by incorporating the enhancer into the lubricants in order to turn the lubricants into greener biodegradable ones and to help in situ bioremediation of lubricant-contaminated environment. This manuscript summarizes our recent efforts relating to the chemistry and technology of biodegradation enhancers for lubricants. Firstly, the chemistry of lubricant biodegradation enhancers was designed based on the principles of bioremediation for the treatment of hydrocarbon contaminated environment. Secondly, the ability of the designed biodegradation enhancers for increasing the biodegradability of unreadily biodegradable industrial lubricants was investigated through biodegradability evaluation tests, microbial population analysis, and biodegradation kinetics modeling. Finally, the impact of biodegradation enhancers on some crucial performance characteristics of lubricants such as lubricity and oxidation stability was tested via tribological evaluation and oxidation determinations. Our results have shown that the designed chemistry of nitrogenous and/or phosphorous compounds such as lauroyl glutamine, oleoyl glycine, oleic diethanolamide phosphate and lauric diethanolamide borate was outstanding in boosting biodegradation of petroleum-based lubricants which was ascribed to increase the microbial population and decrease the oil-water interfacial tension during the biodegradation process. Lubricant

关键词：可生物降解润滑油污染促进剂工程技术氧化安定性环境生物修复润滑油添加剂生物降解动力学

Pulse decomposition-based analysis of PAT/TAT error caused by negative lobes in limited-view conditions

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Chinese Physics B 2015年第2期24卷 276-281页

作者：刘良兵陶超刘晓峻李先利张海涛 Key Laboratory of Modern Acoustics Nanjing University Logistical Engineering University

Pulse decomposition has been proven to be efficient to analyze complicated signals and it is introduced into the photo-acoustic and thermo-acoustic tomography to eliminate reconstruction distortions caused by negative lobes.During image reconstruction,negative lobes bring errors in the estimation of acoustic pulse amplitude,which is closely related to the distribution of absorption coefficient.The negative lobe error degrades imaging quality seriously in limited-view conditions because it cannot be offset so well as in full-view conditions.Therefore,a pulse decomposition formula is provided with detailed deduction to eliminate the negative lobe error and is incorporated into the popular delay-and-sum method for better reconstructing the image without additional complicated computation.Numerical experiments show that the pulse decomposition improves the image quality obviously in the limited-view conditions,such as separating adjacent absorbers,discovering a small absorber despite disturbance from a big absorber nearby,etc.

关键词： photo-acoustic tomography thermo-acoustic tomography limited-view pulse decomposition image reconstruction

Coupled thermo-hygro-mechanical damage model for concrete subjected to high temperatures

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Applied Mathematics and Mechanics(English Edition) 2012年第4期33卷 465-482页

作者：李忠友刘元雪 Department of Architectural and Civil engineering Logistical Engineering University

Based on the theory of mixtures, a coupled thermo-hygro-mechanical （THM） damage model for concrete subjected to high temperatures is presented in this paper. Concrete is considered as a mixture composed of solid skeletons, liquid water, water va- por, dry air, and dissolved air. The macroscopic balance equations of the model consist of the mass conservation equations of each component and the momentum and energy conservation equations of the whole medium mixture. The state equations and the con- stitutive model used in the model are given. Four final governing equations are given in terms of four primary variables, i.e., the displacement components of soil skeletons, the gas pressure, the capillary pressure, and the temperature. The processes involved in the coupled model include evaporation, dehydration, heat and mass transfer, etc. Through the process of deformation failure and the energy properties, the mechanics damage evo- lution equations are established based on the principle of conversation of energy and the Lemaitre equivalent strain assumption. Then, the influence of thermal damage on the mechanical property is considered.

关键词： concrete high temperature thermo-hygro-mechanical （THM） damagemodel

Improvement of Magnetic Field on Tribological Properties of Lubricating Oils with Zinc Butyloctyldithiophosphate

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China Petroleum Processing & Petrochemical Technology 2016年第4期18卷 92-98页

作者： Jiang Zeqi Fang Jianhua Chen Boshui Wu Jiang Wang Jiu Zheng Zhe Department of Military Oil Application & Management engineering Logistical Engineering University

Tribological properties of 150 SN mineral oil and the oils doped with different contents of zinc butyloctyldithiophosphate(T202) under magnetic field or non-magnetic field were evaluated on a four-ball tribotester by applying an external magnetic field around the friction region. Moreover, the morphology and the tribochemical characteristics of worn surfaces were examined by a scanning electron microscope(SEM) and an X-ray photoelectron spectrometer(XPS). Then the lubrication mechanisms were discussed. The tribological test results indicated that the wear scar diameters(WSDs) of steel balls lubricated by the T202-containing lubricating oils and the friction coefficients of the corresponding oil under magnetic field were smaller than those without magnetic affection. The worn surface lubricated with the T202-formulated oils in a magnetic field was smoother than that obtained under the normal condition. Furthermore, the results of XPS analysis indicated that tribochemical films on the surfaces lubricated with T202-doped oils were mainly composed of compounds such as FeSO_4, FeS and ZnS. The atomic concentrations of oxygen, sulfur, iron, zinc and phosphorus species identified in T202 under magnetic field were higher than those without magnetic impact. It can be inferred that the improved anti-wear and friction-reducing ability of T202-doped oils was attributed to the promoted tribochemical reactions and the modification of the worn surfaces induced by magnetic field.

关键词：摩擦学性能外部磁场润滑油锌含量 X射线光电子能谱扫描电子显微镜 T202 XPS分析

Thermal decomposition characteristics and kinetics of methyl linoleate under nitrogen and oxygen atmospheres

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Petroleum Science 2015年第3期12卷 518-524页

作者： Xue-Chun Wang Jian-Hua Fang Bo-Shui Chen Jiu Wang Jiang Wu Di Xia Department of Military Oil Application & Administration engineering Logistical Engineering University

The thermal decomposition characteristics of methyl linoleate （ML） under nitrogen and oxygen atmo- spheres were investigated, using a thermogravimetric analyzer at a heating rate of 10 ~C/min from room tem- perature to 600℃. Furthermore, the pyrolytic and kinetic characteristics of ML at different heating rates were stud- ied. The results showed that the thermal decomposition characteristics of ML under nitrogen and oxygen atmo- spheres were macroscopically similar, although ML exhibited relatively lower thermal stability under an oxy- gen atmosphere than under a nitrogen atmosphere. The initial decomposition temperature, the maximum weight loss temperature, the peak decomposition temperature, and the rate of maximum weight loss of ML under an oxygen atmosphere were much lower than those under a nitrogen atmosphere and increased with increasing heating rates under either oxygen or nitrogen atmosphere. In addition, the kinetic characteristics of thermal decomposition of ML were elucidated based on the experimental results and by the multiple linear regression method. The activation energy, pre-exponential factor, reaction order, and the kinetic equation for thermal decomposition of ML were obtained. The comparison of experimental and calculated data and the analysis of statistical errors of pyrolysis ratios demonstrated that the kinetic model was reliable for pyrolysis of ML with relative errors of about 1%. Finally, the kinetic compensation effect between the pre-exponential factors and the activation energy in the pyrolysis of ML was also confirmed.

关键词： Methyl linoleate Pyrolysis characteristics Kinetics Thermogravimetric analysis Biodiesel