为研究润光养生美容酒皮肤急性毒性、皮肤刺激性及黏膜刺激性。通过观察兔完整皮肤、破损皮肤对润光养生美容酒的反应来评价其外用皮肤急性毒性、刺激性。通过观察大鼠阴道黏膜、兔直肠黏膜对润光养生美容酒的反应来评价其黏膜刺激性。...为研究润光养生美容酒皮肤急性毒性、皮肤刺激性及黏膜刺激性。通过观察兔完整皮肤、破损皮肤对润光养生美容酒的反应来评价其外用皮肤急性毒性、刺激性。通过观察大鼠阴道黏膜、兔直肠黏膜对润光养生美容酒的反应来评价其黏膜刺激性。试验动物完整皮肤、破损皮肤一日内各涂抹润光养生美容酒原液(酒精度为45%vol)4 m L,动物进食、活动正常,体重增加,未见经皮肤吸收引起的急性毒性反应。试验动物完整皮肤、破损皮肤各涂抹润光养生美容酒原液(酒精度为45%vol)1 mL,未见经接触皮肤后产生的刺激性反应。润光养生美容酒原液(酒精度为45%vol),经稀释后酒精度为3.6%vol和1.8%vol的稀释液以及3.6%vol的酒基稀释液均能对兔直肠黏膜产生刺激性作用。在大鼠阴道灌注剂量为10 mL/kg·BW的刺激性试验中,生理盐水组、酒基(酒精度为45%vol)组和润光养生美容酒原液(酒精度为45%vol)组经肉眼检查大鼠阴道组织外观、色泽、大小正常。显微镜下检查阴道组织内膜呈相应生理周期正常改变;未见腺体异常增生或萎缩。与生理盐水组比较,润光养生美容酒原液对大鼠阴道刺激性无显著性差异(p>0.05)。结果表明,润光养生美容酒原液未见经皮肤吸收引起的急性毒性反应和经接触皮肤后产生的刺激性反应。润光养生美容酒原液以及经稀释至酒精度为3.6%vol、酒精度为1.8%vol的稀释液均能对兔直肠产生刺激性作用。润光养生美容酒原液对大鼠阴道未见刺激性作用。展开更多
The production of renewable fuels through water splitting via photocatalytic hydrogen production holds significant promise.Nonetheless,the sluggish kinetics of hydrogen evolution and the inadequate water adsorption on...The production of renewable fuels through water splitting via photocatalytic hydrogen production holds significant promise.Nonetheless,the sluggish kinetics of hydrogen evolution and the inadequate water adsorption on photocatalysts present notable challenges.In this study,we have devised a straightforward hydrothermal method to synthesize Bi_(2)O_(3)(BO)derived from metal‐organic frameworks(MOFs),loaded with flower-like ZnIn_(2)S_(4)(ZIS).This approach substantially enhances water adsorption and surface catalytic reactions,resulting in a remarkable enhancement of photocatalytic activity.By employing triethanolamine(TEOA)as a sacrificial agent,the hydrogen evolution rate achieved with 15%(mass fraction)ZIS loading on BO reached an impressive value of 1610μmol∙h^(−1)∙g^(−1),marking a 6.34-fold increase compared to that observed for bare BO.Furthermore,through density functional theory(DFT)and ab initio molecular dynamics(AIMD)calculations,we have identified the reactions occurring at the ZIS/BO S-scheme heterojunction interface,including the identification of active sites for water adsorption and catalytic reactions.This study provides valuable insights into the development of high-performance composite photocatalytic materials with tailored electronic properties and wettability.展开更多
A nano-MoS2/bentonite composite was synthesized by calcinating MoS3 deposited on bentonite in H2. The obtained composite was characterized using thermogravimetric analysis, X-ray diffractometer, scanning electron micr...A nano-MoS2/bentonite composite was synthesized by calcinating MoS3 deposited on bentonite in H2. The obtained composite was characterized using thermogravimetric analysis, X-ray diffractometer, scanning electron microscope and transmission electron microscope. The results show that nano-MoS2 particles are distributed on the surface of bentonite and form layered structures with layer distance of about 0.64 nm. The composite presents an excellent performance for the removal of methyl orange. Some operation conditions affect the removal efficiency of methyl orange, such as dosage of composite, initial concentration of methyl orange, temperature and pH value. However, light source does not influence the removal efficiency. The removal mechanism is attributed to the adsorption of methyl orange on the nano-MoS2/bentonite composite. The adsorption of methyl orange on the composite is in accordance with the pseudo-second-order kinetic model.展开更多
This paper analyzed 11 lubricating oil 50-1-4Ф samples of different base oil content (standard oil) and 28 used oil samples by Fourier transform mid-infrared spectrometer (FTIR). First, the absorption peak of 1 4...This paper analyzed 11 lubricating oil 50-1-4Ф samples of different base oil content (standard oil) and 28 used oil samples by Fourier transform mid-infrared spectrometer (FTIR). First, the absorption peak of 1 465 cm 1 was selected as the characteristic peak for determining their kinematic viscosities. And then correlation of the kinematic viscosity and the absorbance at characteristic peaks of corresponding infrared spectrum of standard oil and used oil samples was analyzed, re- spectively, and two regression equations were proposed. Finally, the regression equation of standard oil was corrected through other 20 new oil samples. The results show that determining kinematic viscosity of new lubricating oil 50-1-4Ф and the used one by FTIR is feasible and reliable.展开更多
A series of aviation lubrication oil 50-1-4φ samples were prepared with different RP-3 content, and then these sam- ples were analyzed by Fourier transform mid-infrared spectrometer (FTIR). The infrared region of ...A series of aviation lubrication oil 50-1-4φ samples were prepared with different RP-3 content, and then these sam- ples were analyzed by Fourier transform mid-infrared spectrometer (FTIR). The infrared region of 805--755 cm-1 was selected as quantitative area for determining fuel pollution level of aviation lubrication oil. Finally, correlation of the testing peak area and the fuel pollution level of corresponding samples were analyzed, and the regression equation was proposed. The results show that determining jet fuel pollution level of aviation lubricating oil by FTIR is feasible and reliable.展开更多
The cooperative effect of laser surface texturing(LST) and double glow plasma surface alloying on tribological performance of lubricated sliding contacts was investigated.A Nd:YAG laser was used to generate microdimpl...The cooperative effect of laser surface texturing(LST) and double glow plasma surface alloying on tribological performance of lubricated sliding contacts was investigated.A Nd:YAG laser was used to generate microdimples on steel surfaces. Dimples with the diameter of 150μm and the depth of 30-35μm distributed circumferentially on the disc surface.The alloying element Cr was sputtered to the laser texturing steel surface by double glow plasma technique.A deep diffusion layer with a thickness of 30μm and a high hardness of HV900 was formed in this alloy.Tribological experiments of three types of samples(smooth,texturing and texturing+alloying) were conducted with a ring-on-disc tribometer to simulate the face seal.It is found that,in comparison with smooth steel surfaces,the laser texturing samples significantly reduce the friction coefficient.Moreover,the lower wear rate of the sample treated with the two surface techniques is observed.展开更多
Wetting condition of micro/nanostructured surface has received tremendous attention due to the potential applications in commercial,industrial,and military areas.Surfaces with extreme wetting properties,e.g.,superhydr...Wetting condition of micro/nanostructured surface has received tremendous attention due to the potential applications in commercial,industrial,and military areas.Surfaces with extreme wetting properties,e.g.,superhydrophobic or superhydrophilic,are extensively employed due to their superior anti-icing,drag reduction,enhanced boiling heat transfer,self-cleaning,and anti-bacterial properties depending on solid-liquid interfacial interactions.Laser-based techniques have gained popularity in recent years to create micro/nano-structured surface owing to their high flexibility,system precision,and ease for automation.These techniques create laser induced periodic surface structures(LIPSS)or hierarchical structures on substrate material.However,micro/nanostructures alone cannot attain the desired wettability.Subsequent modification of surface chemistry is essentially needed to achieve target extreme wettability.This review paper aims to provide a comprehensive review for both laser texturing techniques and the following chemistry modification methods.Recent research progress and fundamental mechanisms of surface structure generation via different types of lasers and various chemistry modification methods are discussed.The complex combination between the laser texturing and surface chemistry modification methods to decide the final wetting condition is presented.More importantly,surface functionalities of these surfaces with extreme wetting properties are discussed.Lastly,prospects for future research are proposed and discussed.展开更多
A BN-containing additive,the boron and nitrogen modified rapeseed oil (abbreviated as BNR),was prepared by chemical modification of rapeseed oil with boric and nitrous compounds.The friction and wear performances of t...A BN-containing additive,the boron and nitrogen modified rapeseed oil (abbreviated as BNR),was prepared by chemical modification of rapeseed oil with boric and nitrous compounds.The friction and wear performances of the AZ91D magnesium alloy against the GCr15 bearing steel under lubrication of rapeseed oil containing BNR were evaluated on a SRV tribotester.The topography and chemical species of the worn surfaces of magnesium alloy were analyzed by a scanning electron microscope (SEM) and an X-ray photoelectron spectroscope (XPS),respectively.The test results indicated that the friction and wear of the magnesium alloy-steel tribomates could be effectively reduced by incorporating BNR into the rapeseed oil lubricant.The friction coefficients and the wear scars of magnesium alloy decreased with an increasing content of BNR.The surface lubricated with the BNR-doped rapeseed oil demonstrated less wear as compared with that lubricated with neat rapeseed oil.The enhanced anti-wear and friction-reducing abilities of rapeseed oil provided by BNR in the lubrication of magnesium alloy against steel were ascribed to the formation of a composite boundary lubrication film due to the strong adsorption of BNR and rapeseed oil onto the lubricated surfaces and their tribochemical reactions with magnesium alloy.展开更多
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 ...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.展开更多
The oil solubility of synthetic oleic acid tris-(2-hydroxyethyl) isocyanurate phosphate ester(abbreviated as OHTP hereinafter) and its influence on the biodegradability and tribological performance of 400 SN mineral o...The oil solubility of synthetic oleic acid tris-(2-hydroxyethyl) isocyanurate phosphate ester(abbreviated as OHTP hereinafter) and its influence on the biodegradability and tribological performance of 400 SN mineral oil were investigated on a tester and a four-ball tribotester,respectively,for fast evaluating the biodegradability of lubricants.Furthermore,the morphologies and tribochemical species of the worn surfaces lubricated by OHTP-doped oil were studied by scanning electron microscope(SEM) and X-ray photoelectron spectroscope(XPS).The results indicated that OHTP possessed good oil solubility and could improve obviously the biodegradability,the extreme pressure properties,the anti-wear properties and friction-reducing properties of the 400 SN mineral oil.The analytical results of XPS spectra showed that the composite boundary lubrication films were mainly composed of absorbed films and tribochemical species such as FePO-4,Fe_3(PO_4)_2,Fe_2O_3 and Fe_3O_4,which contributed to improving the tribological performances.展开更多
An interfacial study between molten iron and the prereduced ilmenite with carbon was conducted at different melting temperatures by the sessile droplet method.The wetting characteristics between molten iron and the pr...An interfacial study between molten iron and the prereduced ilmenite with carbon was conducted at different melting temperatures by the sessile droplet method.The wetting characteristics between molten iron and the prereduced ilmenites with carbon were investigated by measuring contact angle of the droplet of molten iron on the prereduced ilmenite substrate.The images of the interface were also examined by the optical microscope and SEM equipped with EDS.The volume of molten iron increased with the melting temperature increasing when titania or high-content titania slag was used as the substrate.The contact angle decreased with the melting temperature increasing and it was independent on time at constant temperature.The contact angle was positively correlated with the reduction degree of the ilmenite,but the work of adhesion was negatively correlated with it.Higher smelting temperature was beneficial to the separation of iron and Ti oxides.The permeability of molten iron into the prereduced ilmenite with carbon was more obvious with reduction degree increasing owing to the high porosity of prereduced ilmenite.展开更多
An experimental device able to determine the moisture content of wood usingX-ray attenuation is used to study the imbibition of beech samples (Fagus silvatica). The apparatusincludes an X-ray generator, a protective t...An experimental device able to determine the moisture content of wood usingX-ray attenuation is used to study the imbibition of beech samples (Fagus silvatica). The apparatusincludes an X-ray generator, a protective tube, collimating plates and a 50 mm detector. Detectedparticles can be categorised by energy (accuracy of the order of 20%) or by position (accuracy 100μm). The independent choice of both the energy spectrum (through the voltage) and the counting rate(through the current intensity) makes the installation very flexible. However, a rigorous treatmentis necessary to deal with the attenuation of a polychromatic spectrum. The appropriate calculationsare presented and validated with homogeneous samples made of wood and water. In addition, someresults are presented with samples heterogeneous in density and moisture content. Finally, theexperimental device is used to study the evolution of moisture content during saturationexperiments, for which the moisture migration is mainly due to capillary forces. The geometricalconfiguration was so arranged that the transfer can be studied in two directions simultaneously.展开更多
tert-Butylation of toluene with tert-butanol used as the alkylating agent was investigated over the activated bentonite and HY zeolite used as the catalyst.The influences of various butylation reaction parameters,incl...tert-Butylation of toluene with tert-butanol used as the alkylating agent was investigated over the activated bentonite and HY zeolite used as the catalyst.The influences of various butylation reaction parameters,including the toluene/tert-butanol ratio,the reaction temperature,and the space velocity were discussed.The optimal results were obtained at a reaction temperature of 180 ℃,a space velocity of 4 h-1,and a mole ratio of toluene to tert-butanol equating to 2.The structure and acidic properties of catalyst were characterized by the BET method and the Fourier transform infrared (FTIR) spectroscopy.Compared with the HY zeolite,the activated bentonite possessed high activity for toluene conversion and high para-selectivity because it had larger pore diameter,smaller micropore surface area and higher ratio of total Lewis acids to total Br nsted acids.展开更多
To obtain effective surface morphology to control surface wettability, this work investigated the influence of protuberant and concave morphology, which are respectively represented by circle-dimpled and micro-square-...To obtain effective surface morphology to control surface wettability, this work investigated the influence of protuberant and concave morphology, which are respectively represented by circle-dimpled and micro-square-convex morphology, on surface wettability. The geometric morphologies were processed on silicon carbide (SIC) surfaces by a laser-marking machine, and surface wettability was monitored by the measurement of contact angles using the sessile drop method. Correlation analysis between contact angles and morphology parameters was conducted to determine the extent of influence. The results showed that the circle-dimpled diameter had a signific^mt influence on surface wettability, whereas grooved width did not. Additionally the depth of dimples and grooves exerted less influence on controlling wetting behaviors. In addition, surface wettability transformed from a superhydrophilic state to a hydrophobic state on micro-square-convex surfaces; contact angles on cir- cle-dimpled surfaces showed a relatively slow transformation, though the surface wettability also underwent the state change.展开更多
Surface texturing has been considered as an effective approach to improve the tribological performances.Based on the consideration of enhancing the tribological performance,the experiments are carried out to investiga...Surface texturing has been considered as an effective approach to improve the tribological performances.Based on the consideration of enhancing the tribological performance,the experiments are carried out to investigate tribological performance of triangular textures in water lubrication.The textures are generated by the Nd:YAG laser marking system,with an area density of 20%and a depth of 7 m and are distributed uniformly on the surface of the SiC rings.Compared with the circular textures,the triangular textures have obvious tribological anisotropy.The triangular textures in clockwise direction show the best friction reduction effect among the three textures.The friction reduction mechanisms of the triangular textures in clockwise direction are also analyzed and discussed.展开更多
For environmental protection, energy conservation, and other reasons, water-based lubricants are increasingly chosen to replace oil lubricants. Water-based lubricants are divided into emulsified and solution types. So...For environmental protection, energy conservation, and other reasons, water-based lubricants are increasingly chosen to replace oil lubricants. Water-based lubricants are divided into emulsified and solution types. Solution type water-based lubricants have attracted significant attention for the good stability, easy biodegradability, and safety for workers. However, some problems exist with current solution type water-based lubricants, such as poor lubricity and corrosion resistance. During the cold-rolling process, A1 plate rolled using oil-based lubricant lubrication shows metallic luster, but that rolled using water-based lubricant shows corrosion spots, black strips, and no metallic luster. Therefore, this study mainly analyzed the reasons for the darkness of A1 plate cold-rolled with water solution lubricants. The differences in plate surfaces lubricated by water solution and oil were investigated by scanning electron microscopy, auger electron spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The analysis results showed that the surface of the oil-lubricated sample is smooth, the oxygen content is low, and the oxide layer is thin, while the surface of the water solution-lubricated sample is rough, the oxygen content is high, the chemical composition is more complex, and the oxide layer is not uniform and thick.展开更多
This paper describes a study of point contact elastohydrodynamic(EHD)lubrication behavior at high speeds(up to 20 m s1).Central film thicknesses were measured by optical interferometry device.The influence of slide-ro...This paper describes a study of point contact elastohydrodynamic(EHD)lubrication behavior at high speeds(up to 20 m s1).Central film thicknesses were measured by optical interferometry device.The influence of slide-roll ratio and operating temperature on the central film thickness was determined.The influence of thermal effects on the reduction of film thickness was discussed via the analysis of numerical simulation method considering thermal effects.Subsequently,the experimental data was used to amend a set of unified parameters for the thermal corrections for different types of oil at high speeds.展开更多
文摘为研究润光养生美容酒皮肤急性毒性、皮肤刺激性及黏膜刺激性。通过观察兔完整皮肤、破损皮肤对润光养生美容酒的反应来评价其外用皮肤急性毒性、刺激性。通过观察大鼠阴道黏膜、兔直肠黏膜对润光养生美容酒的反应来评价其黏膜刺激性。试验动物完整皮肤、破损皮肤一日内各涂抹润光养生美容酒原液(酒精度为45%vol)4 m L,动物进食、活动正常,体重增加,未见经皮肤吸收引起的急性毒性反应。试验动物完整皮肤、破损皮肤各涂抹润光养生美容酒原液(酒精度为45%vol)1 mL,未见经接触皮肤后产生的刺激性反应。润光养生美容酒原液(酒精度为45%vol),经稀释后酒精度为3.6%vol和1.8%vol的稀释液以及3.6%vol的酒基稀释液均能对兔直肠黏膜产生刺激性作用。在大鼠阴道灌注剂量为10 mL/kg·BW的刺激性试验中,生理盐水组、酒基(酒精度为45%vol)组和润光养生美容酒原液(酒精度为45%vol)组经肉眼检查大鼠阴道组织外观、色泽、大小正常。显微镜下检查阴道组织内膜呈相应生理周期正常改变;未见腺体异常增生或萎缩。与生理盐水组比较,润光养生美容酒原液对大鼠阴道刺激性无显著性差异(p>0.05)。结果表明,润光养生美容酒原液未见经皮肤吸收引起的急性毒性反应和经接触皮肤后产生的刺激性反应。润光养生美容酒原液以及经稀释至酒精度为3.6%vol、酒精度为1.8%vol的稀释液均能对兔直肠产生刺激性作用。润光养生美容酒原液对大鼠阴道未见刺激性作用。
文摘The production of renewable fuels through water splitting via photocatalytic hydrogen production holds significant promise.Nonetheless,the sluggish kinetics of hydrogen evolution and the inadequate water adsorption on photocatalysts present notable challenges.In this study,we have devised a straightforward hydrothermal method to synthesize Bi_(2)O_(3)(BO)derived from metal‐organic frameworks(MOFs),loaded with flower-like ZnIn_(2)S_(4)(ZIS).This approach substantially enhances water adsorption and surface catalytic reactions,resulting in a remarkable enhancement of photocatalytic activity.By employing triethanolamine(TEOA)as a sacrificial agent,the hydrogen evolution rate achieved with 15%(mass fraction)ZIS loading on BO reached an impressive value of 1610μmol∙h^(−1)∙g^(−1),marking a 6.34-fold increase compared to that observed for bare BO.Furthermore,through density functional theory(DFT)and ab initio molecular dynamics(AIMD)calculations,we have identified the reactions occurring at the ZIS/BO S-scheme heterojunction interface,including the identification of active sites for water adsorption and catalytic reactions.This study provides valuable insights into the development of high-performance composite photocatalytic materials with tailored electronic properties and wettability.
基金Project (2011M500110) supported by the Postdoctoral Science Foundation of ChinaProject (50905054) supported by the National Natural Science Foundation of ChinaProject (12RC03) supported by Hefei University, China
文摘A nano-MoS2/bentonite composite was synthesized by calcinating MoS3 deposited on bentonite in H2. The obtained composite was characterized using thermogravimetric analysis, X-ray diffractometer, scanning electron microscope and transmission electron microscope. The results show that nano-MoS2 particles are distributed on the surface of bentonite and form layered structures with layer distance of about 0.64 nm. The composite presents an excellent performance for the removal of methyl orange. Some operation conditions affect the removal efficiency of methyl orange, such as dosage of composite, initial concentration of methyl orange, temperature and pH value. However, light source does not influence the removal efficiency. The removal mechanism is attributed to the adsorption of methyl orange on the nano-MoS2/bentonite composite. The adsorption of methyl orange on the composite is in accordance with the pseudo-second-order kinetic model.
文摘This paper analyzed 11 lubricating oil 50-1-4Ф samples of different base oil content (standard oil) and 28 used oil samples by Fourier transform mid-infrared spectrometer (FTIR). First, the absorption peak of 1 465 cm 1 was selected as the characteristic peak for determining their kinematic viscosities. And then correlation of the kinematic viscosity and the absorbance at characteristic peaks of corresponding infrared spectrum of standard oil and used oil samples was analyzed, re- spectively, and two regression equations were proposed. Finally, the regression equation of standard oil was corrected through other 20 new oil samples. The results show that determining kinematic viscosity of new lubricating oil 50-1-4Ф and the used one by FTIR is feasible and reliable.
文摘A series of aviation lubrication oil 50-1-4φ samples were prepared with different RP-3 content, and then these sam- ples were analyzed by Fourier transform mid-infrared spectrometer (FTIR). The infrared region of 805--755 cm-1 was selected as quantitative area for determining fuel pollution level of aviation lubrication oil. Finally, correlation of the testing peak area and the fuel pollution level of corresponding samples were analyzed, and the regression equation was proposed. The results show that determining jet fuel pollution level of aviation lubricating oil by FTIR is feasible and reliable.
基金Project(2007046) supported by High Technology Research Project of Jiangsu Province,China
文摘The cooperative effect of laser surface texturing(LST) and double glow plasma surface alloying on tribological performance of lubricated sliding contacts was investigated.A Nd:YAG laser was used to generate microdimples on steel surfaces. Dimples with the diameter of 150μm and the depth of 30-35μm distributed circumferentially on the disc surface.The alloying element Cr was sputtered to the laser texturing steel surface by double glow plasma technique.A deep diffusion layer with a thickness of 30μm and a high hardness of HV900 was formed in this alloy.Tribological experiments of three types of samples(smooth,texturing and texturing+alloying) were conducted with a ring-on-disc tribometer to simulate the face seal.It is found that,in comparison with smooth steel surfaces,the laser texturing samples significantly reduce the friction coefficient.Moreover,the lower wear rate of the sample treated with the two surface techniques is observed.
基金Project(52105175)supported by the National Natural Science Foundation of ChinaProject(BK20210235)supported by the Natural Science Foundation of Jiangsu Province,ChinaProject(JSSCBS20210121)supported by the Jiangsu Provincial Innovative and Entrepreneurial Doctor Program,China。
文摘Wetting condition of micro/nanostructured surface has received tremendous attention due to the potential applications in commercial,industrial,and military areas.Surfaces with extreme wetting properties,e.g.,superhydrophobic or superhydrophilic,are extensively employed due to their superior anti-icing,drag reduction,enhanced boiling heat transfer,self-cleaning,and anti-bacterial properties depending on solid-liquid interfacial interactions.Laser-based techniques have gained popularity in recent years to create micro/nano-structured surface owing to their high flexibility,system precision,and ease for automation.These techniques create laser induced periodic surface structures(LIPSS)or hierarchical structures on substrate material.However,micro/nanostructures alone cannot attain the desired wettability.Subsequent modification of surface chemistry is essentially needed to achieve target extreme wettability.This review paper aims to provide a comprehensive review for both laser texturing techniques and the following chemistry modification methods.Recent research progress and fundamental mechanisms of surface structure generation via different types of lasers and various chemistry modification methods are discussed.The complex combination between the laser texturing and surface chemistry modification methods to decide the final wetting condition is presented.More importantly,surface functionalities of these surfaces with extreme wetting properties are discussed.Lastly,prospects for future research are proposed and discussed.
基金the financial support from the National Natural Science Foundation of China (project No. 50975282)
文摘A BN-containing additive,the boron and nitrogen modified rapeseed oil (abbreviated as BNR),was prepared by chemical modification of rapeseed oil with boric and nitrous compounds.The friction and wear performances of the AZ91D magnesium alloy against the GCr15 bearing steel under lubrication of rapeseed oil containing BNR were evaluated on a SRV tribotester.The topography and chemical species of the worn surfaces of magnesium alloy were analyzed by a scanning electron microscope (SEM) and an X-ray photoelectron spectroscope (XPS),respectively.The test results indicated that the friction and wear of the magnesium alloy-steel tribomates could be effectively reduced by incorporating BNR into the rapeseed oil lubricant.The friction coefficients and the wear scars of magnesium alloy decreased with an increasing content of BNR.The surface lubricated with the BNR-doped rapeseed oil demonstrated less wear as compared with that lubricated with neat rapeseed oil.The enhanced anti-wear and friction-reducing abilities of rapeseed oil provided by BNR in the lubrication of magnesium alloy against steel were ascribed to the formation of a composite boundary lubrication film due to the strong adsorption of BNR and rapeseed oil onto the lubricated surfaces and their tribochemical reactions with magnesium alloy.
基金financial support provided by the National Natural Science Foundation of China(Project No.51375491)the Natural Science Foundation of Chongqing(Project No.CSTC,2014JCYJAA50021)the Innovation Fund of Logistical Engineering University(Project No.YZ13-43703)
文摘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.
基金the financial support from the National Defense Science Technology Foundation (Project No.3604003)the National Natural Science Foundation of China (Project No.51375491)+1 种基金the Natural Science Foundation of Chongqing (Project No.CSTC,2014JCYJAA50021)the Natural Science Foundation of Chongqing (Project No.cstc2017jcyj AX0058)
文摘The oil solubility of synthetic oleic acid tris-(2-hydroxyethyl) isocyanurate phosphate ester(abbreviated as OHTP hereinafter) and its influence on the biodegradability and tribological performance of 400 SN mineral oil were investigated on a tester and a four-ball tribotester,respectively,for fast evaluating the biodegradability of lubricants.Furthermore,the morphologies and tribochemical species of the worn surfaces lubricated by OHTP-doped oil were studied by scanning electron microscope(SEM) and X-ray photoelectron spectroscope(XPS).The results indicated that OHTP possessed good oil solubility and could improve obviously the biodegradability,the extreme pressure properties,the anti-wear properties and friction-reducing properties of the 400 SN mineral oil.The analytical results of XPS spectra showed that the composite boundary lubrication films were mainly composed of absorbed films and tribochemical species such as FePO-4,Fe_3(PO_4)_2,Fe_2O_3 and Fe_3O_4,which contributed to improving the tribological performances.
基金Project(2008AA06Z1071) supported by the National High-tech Research and Development Program of China Project(50474043) supported by the National Natural Science Foundation of China
文摘An interfacial study between molten iron and the prereduced ilmenite with carbon was conducted at different melting temperatures by the sessile droplet method.The wetting characteristics between molten iron and the prereduced ilmenites with carbon were investigated by measuring contact angle of the droplet of molten iron on the prereduced ilmenite substrate.The images of the interface were also examined by the optical microscope and SEM equipped with EDS.The volume of molten iron increased with the melting temperature increasing when titania or high-content titania slag was used as the substrate.The contact angle decreased with the melting temperature increasing and it was independent on time at constant temperature.The contact angle was positively correlated with the reduction degree of the ilmenite,but the work of adhesion was negatively correlated with it.Higher smelting temperature was beneficial to the separation of iron and Ti oxides.The permeability of molten iron into the prereduced ilmenite with carbon was more obvious with reduction degree increasing owing to the high porosity of prereduced ilmenite.
文摘An experimental device able to determine the moisture content of wood usingX-ray attenuation is used to study the imbibition of beech samples (Fagus silvatica). The apparatusincludes an X-ray generator, a protective tube, collimating plates and a 50 mm detector. Detectedparticles can be categorised by energy (accuracy of the order of 20%) or by position (accuracy 100μm). The independent choice of both the energy spectrum (through the voltage) and the counting rate(through the current intensity) makes the installation very flexible. However, a rigorous treatmentis necessary to deal with the attenuation of a polychromatic spectrum. The appropriate calculationsare presented and validated with homogeneous samples made of wood and water. In addition, someresults are presented with samples heterogeneous in density and moisture content. Finally, theexperimental device is used to study the evolution of moisture content during saturationexperiments, for which the moisture migration is mainly due to capillary forces. The geometricalconfiguration was so arranged that the transfer can be studied in two directions simultaneously.
文摘tert-Butylation of toluene with tert-butanol used as the alkylating agent was investigated over the activated bentonite and HY zeolite used as the catalyst.The influences of various butylation reaction parameters,including the toluene/tert-butanol ratio,the reaction temperature,and the space velocity were discussed.The optimal results were obtained at a reaction temperature of 180 ℃,a space velocity of 4 h-1,and a mole ratio of toluene to tert-butanol equating to 2.The structure and acidic properties of catalyst were characterized by the BET method and the Fourier transform infrared (FTIR) spectroscopy.Compared with the HY zeolite,the activated bentonite possessed high activity for toluene conversion and high para-selectivity because it had larger pore diameter,smaller micropore surface area and higher ratio of total Lewis acids to total Br nsted acids.
基金supported by the National Natural Science Foundation of China(Grant No.51275473)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LR14E050001)the Tribology Science Fund of State Key Laboratory of Tribology of China(Grant No.SKLTKF14B13)
文摘To obtain effective surface morphology to control surface wettability, this work investigated the influence of protuberant and concave morphology, which are respectively represented by circle-dimpled and micro-square-convex morphology, on surface wettability. The geometric morphologies were processed on silicon carbide (SIC) surfaces by a laser-marking machine, and surface wettability was monitored by the measurement of contact angles using the sessile drop method. Correlation analysis between contact angles and morphology parameters was conducted to determine the extent of influence. The results showed that the circle-dimpled diameter had a signific^mt influence on surface wettability, whereas grooved width did not. Additionally the depth of dimples and grooves exerted less influence on controlling wetting behaviors. In addition, surface wettability transformed from a superhydrophilic state to a hydrophobic state on micro-square-convex surfaces; contact angles on cir- cle-dimpled surfaces showed a relatively slow transformation, though the surface wettability also underwent the state change.
基金supported by the National Basic Research Program of China(Grant No.2009CB724304)the National Key Technology R&D Program(Grant No.2011BAF09B05)the National Natural Science Foundation of China(Grant No.50975157)
文摘Surface texturing has been considered as an effective approach to improve the tribological performances.Based on the consideration of enhancing the tribological performance,the experiments are carried out to investigate tribological performance of triangular textures in water lubrication.The textures are generated by the Nd:YAG laser marking system,with an area density of 20%and a depth of 7 m and are distributed uniformly on the surface of the SiC rings.Compared with the circular textures,the triangular textures have obvious tribological anisotropy.The triangular textures in clockwise direction show the best friction reduction effect among the three textures.The friction reduction mechanisms of the triangular textures in clockwise direction are also analyzed and discussed.
基金supported by the National Key Basic Research Program of China(Grant No.2013CB934200)the National Natural Science Foundation of China(Grant Nos.51335005&51527901)
文摘For environmental protection, energy conservation, and other reasons, water-based lubricants are increasingly chosen to replace oil lubricants. Water-based lubricants are divided into emulsified and solution types. Solution type water-based lubricants have attracted significant attention for the good stability, easy biodegradability, and safety for workers. However, some problems exist with current solution type water-based lubricants, such as poor lubricity and corrosion resistance. During the cold-rolling process, A1 plate rolled using oil-based lubricant lubrication shows metallic luster, but that rolled using water-based lubricant shows corrosion spots, black strips, and no metallic luster. Therefore, this study mainly analyzed the reasons for the darkness of A1 plate cold-rolled with water solution lubricants. The differences in plate surfaces lubricated by water solution and oil were investigated by scanning electron microscopy, auger electron spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. The analysis results showed that the surface of the oil-lubricated sample is smooth, the oxygen content is low, and the oxide layer is thin, while the surface of the water solution-lubricated sample is rough, the oxygen content is high, the chemical composition is more complex, and the oxide layer is not uniform and thick.
基金supported by National Nature Science Foundation of China(Grant Nos.51027007,51021064)the International Science&Technology Cooperation Project(Grant No.2011DFA70980)
文摘This paper describes a study of point contact elastohydrodynamic(EHD)lubrication behavior at high speeds(up to 20 m s1).Central film thicknesses were measured by optical interferometry device.The influence of slide-roll ratio and operating temperature on the central film thickness was determined.The influence of thermal effects on the reduction of film thickness was discussed via the analysis of numerical simulation method considering thermal effects.Subsequently,the experimental data was used to amend a set of unified parameters for the thermal corrections for different types of oil at high speeds.