【目的】探究温拌沥青混合料黏附机理,拓展温拌沥青与集料黏附性研究方法。【方法】使用原子力显微镜(atomic force microscope,AFM)测得分别加入Sasobit类温拌剂H01(质量分数分别为1.0%、3.0%、5.0%)和表面活性剂类温拌剂H02(质量分数...【目的】探究温拌沥青混合料黏附机理,拓展温拌沥青与集料黏附性研究方法。【方法】使用原子力显微镜(atomic force microscope,AFM)测得分别加入Sasobit类温拌剂H01(质量分数分别为1.0%、3.0%、5.0%)和表面活性剂类温拌剂H02(质量分数分别为0.3%、0.5%、0.7%)的温拌沥青试样黏附力,并经JKR(Johnson-Kendall-Roberts)模型和表面能理论将其转换为沥青表面能,计算沥青-花岗岩和沥青-玄武岩体系的无水、有水黏附功,并与水煮试验、水稳定性试验结果进行对比分析;对基于AFM测得的温拌沥青退针力曲线进行积分,得到黏附性指标G,并将其与沥青表面能进行相关性拟合。【结果】两类温拌剂的加入均降低了温拌沥青-集料体系的黏附功,温拌沥青-花岗岩体系的无水黏附功比温拌沥青-玄武岩体系的大,有水黏附功则相反;基于AFM求解得到的H01温拌沥青-玄武岩体系黏附功的变化趋势与水稳定性试验结果相同,而H02温拌沥青-玄武岩体系的则相反;黏附性指标G与沥青表面能之间具有较好的相关性。【结论】相比温拌沥青-玄武岩体系,温拌沥青-花岗岩体系更容易发生水损害;基于AFM求解沥青-玄武岩体系黏附功的方法适用于Sasobit类温拌沥青,不适用于表面活性剂类温拌沥青;本文提出的黏附性指标G为评价温拌沥青-集料体系黏附性提供了新的量化指标。展开更多
Three kinds of titanium surface especially the HA surface are analyzed. Titanium was treated by 3 kinds of methods that were acid ＆ alkali, calcic solution and apathe solution. Samples were observed by optic micros...Three kinds of titanium surface especially the HA surface are analyzed. Titanium was treated by 3 kinds of methods that were acid ＆ alkali, calcic solution and apathe solution. Samples were observed by optic microscope and atomic force microscope （ AFM ） . The typical surface morphology of the acid and alkali group is little holes, and on the two HA surface the tiny protuberances is typical. The surface treated by apatite solution was smoother than the two formers. The rough surface treated with acid and alkali was propitious to Ca^＋ , P^- and proteins＇ adhesion, and the relatively smooth HA surface was of benefit to the cell adhesion.展开更多
During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a rest...During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.展开更多
In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly effi...In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly efficacious approach to enhance the teaching level of experimental courses in medicinal botany.The implementation of a digital microscope mutual system in experimental teaching not only enhances students practical skills in laboratory operations but also increases classroom efficiency.Furthermore,it supports personalized development among students while fostering innovative thinking,independent learning capabilities,and analysis and problem-solving skills.Additionally,this approach contributes to the enhancement of students scientific literacy.展开更多
Fine particle detachment and subsequent migration can lead to severe pore plugging and consequent permeability decline.Therefore,it is crucial to quantify the critical condition when fine particle detachment occurs.Th...Fine particle detachment and subsequent migration can lead to severe pore plugging and consequent permeability decline.Therefore,it is crucial to quantify the critical condition when fine particle detachment occurs.The frequently observed deviations or even contradictions between experimental results and theoretical predictions of fines detachment arise from an insufficient understanding of adhesion force that can be highly influenced by salinity and temperature.To clarify the intrinsic influence of salinity and temperature on fines detachment,adhesion forces between carboxyl microspheres and hydrophilic silica substrates in an aqueous medium were measured at various salinities and tempera-tures using atomic force microscopy(AFM).The AFM-measured adhesion force decreases with increasing salinity or temperature.Trends of mean measured adhesion forces with temperature and salinity were compared with the DLVO and XDLVO theories.DLVO theory captured the trend with temperature via the impact of temperature on electric double layer interactions,whereas XDLVO theory captured the observed trend with salinity via the impact of salinity on the repulsive hydration force.Our results highlight the significance of hydration force in accurately predicting the fate of fines in porous media.展开更多
With the intensification of lunar exploration,the failure risk caused by the adsorption of lunar dust on the spacecraft surface cannot be ignored.Therefore,three types of typical spatial solid lubrication films,namely...With the intensification of lunar exploration,the failure risk caused by the adsorption of lunar dust on the spacecraft surface cannot be ignored.Therefore,three types of typical spatial solid lubrication films,namely polytetrafluoroethylene(PTFE),amorphous carbon(a-C)and molybdenum disulfide(MoS2),were prepared as test samples.Firstly,the surface free energy parameters of the material were measured using a contact Angle measuring instrument.At the same time,atomic force microscopy(AFM)was used to quantify the adhesion of the film samples based on the lunar dust micro-adsorption model.In order to investigate the influence of the test environment,the environmental pressure was adjusted to normal pressure environment and high vacuum environment with a vacuum degree of 10−6 Pa for testing.The results indicate a positive correlation between surface energy and adhesion.As surface energy increases,molecules tend to move closer,forming a stronger attraction and thus enhancing surface adhesion.In addition,AFM was used to measure the adhesion force under atmospheric pressure and vacuum conditions,revealing that parameters measured in atmospheric environment were generally higher than those measured in vacuum,which effectively verified the existence of capillary force in the microscopic adsorption model and its influence on the adhesion effect.Through the test comparison of three groups of typical solid lubricating films,it is found that MoS2 has a lower adhesion effect than the other two groups of films,which can effectively reduce the adhesion phenomenon of lunar dust on the surface of the material,and provide suitable materials for future lunar exploration and manned lunar missions.展开更多
To investigate the nucleation behavior during the single-phased metallic solidification process,the commercial ultrapure ferritic stainless steels with no(Initial steel)and various melt treatments(R1,MR1,Y2,MY1,and M1...To investigate the nucleation behavior during the single-phased metallic solidification process,the commercial ultrapure ferritic stainless steels with no(Initial steel)and various melt treatments(R1,MR1,Y2,MY1,and M1 steels)were used to carry out the differential scanning colorimetry(DSC)and high-temperature confocal laser scanning microscope(HT-CLSM)experiments.Based on the results of DSC experiments,the equilibrium solidification process as well as the relationship among the critical undercooling degree(△T_(c)^(DSC)),latent heat of fusion/crystallization(△H_(f)/△H_(c)),equiaxed grain ratio(ER),and average grain size(△_(ave)^(ingot))was revealed.ER is increased with the decreasing△T_(c)^(DSC)and increasing△H_(f)/△H_(c);however,△_(ave)^(ingot)is decreased with them.Referring to the results of HT-CLSM experiments,the average sizes of micro-/macrostructures(d_(ave)/D_(ave)/)are decreased with the increasing cooling rate,as well as the difference between and apparent critical undercooling degree(△T_(c)^(CLSM))was revealed.The heterogeneous nucleation of the crystal nuclei occurs only if△T_(c)^(CLSM)>△T_(c)^(DSC).Combining with the interfacial wetting-lattice mismatch heterogeneous nucleation model,the dynamic mechanism of the metallic solidification was revealed.The as-cast grains of the melt-treated samples were obviously refined,owing to the much higher actual heterogeneous nucleation rates(I_(heter.,i))obtained through melt treatments,and the heterogeneous nucleation rates(I_(heter.,ij))for all samples are increased with the cooling rates,firmly confirming that the as-cast grains of each sample could be refined by the increasing cooling rates.展开更多
文摘【目的】探究温拌沥青混合料黏附机理,拓展温拌沥青与集料黏附性研究方法。【方法】使用原子力显微镜(atomic force microscope,AFM)测得分别加入Sasobit类温拌剂H01(质量分数分别为1.0%、3.0%、5.0%)和表面活性剂类温拌剂H02(质量分数分别为0.3%、0.5%、0.7%)的温拌沥青试样黏附力,并经JKR(Johnson-Kendall-Roberts)模型和表面能理论将其转换为沥青表面能,计算沥青-花岗岩和沥青-玄武岩体系的无水、有水黏附功,并与水煮试验、水稳定性试验结果进行对比分析;对基于AFM测得的温拌沥青退针力曲线进行积分,得到黏附性指标G,并将其与沥青表面能进行相关性拟合。【结果】两类温拌剂的加入均降低了温拌沥青-集料体系的黏附功,温拌沥青-花岗岩体系的无水黏附功比温拌沥青-玄武岩体系的大,有水黏附功则相反;基于AFM求解得到的H01温拌沥青-玄武岩体系黏附功的变化趋势与水稳定性试验结果相同,而H02温拌沥青-玄武岩体系的则相反;黏附性指标G与沥青表面能之间具有较好的相关性。【结论】相比温拌沥青-玄武岩体系,温拌沥青-花岗岩体系更容易发生水损害;基于AFM求解沥青-玄武岩体系黏附功的方法适用于Sasobit类温拌沥青,不适用于表面活性剂类温拌沥青;本文提出的黏附性指标G为评价温拌沥青-集料体系黏附性提供了新的量化指标。
文摘Three kinds of titanium surface especially the HA surface are analyzed. Titanium was treated by 3 kinds of methods that were acid ＆ alkali, calcic solution and apathe solution. Samples were observed by optic microscope and atomic force microscope （ AFM ） . The typical surface morphology of the acid and alkali group is little holes, and on the two HA surface the tiny protuberances is typical. The surface treated by apatite solution was smoother than the two formers. The rough surface treated with acid and alkali was propitious to Ca^＋ , P^- and proteins＇ adhesion, and the relatively smooth HA surface was of benefit to the cell adhesion.
基金financially supported by the National Natural Science Foundation of China(Nos.52274315 and 52374320)the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-22-011A1 and FRF-DF22-16)。
文摘During the continuous casting process of high-Mn high-Al steels,various types of gases such as Ar need to escape through the top of the mold.In which,the behavior of bubbles traversing the liquid slag serves as a restrictive link,closely associated with viscosity and the thickness of liquid slag.In contrast to two-dimensional surface observation,three-dimensional(3D)analysis method can offer a more intuitive,accurate,and comprehensive information.Therefore,this study employs a 3D X-ray microscope(3D-XRM)to obtained spatial distribution and 3D morphological characteristics of residual bubbles in mold flux under different basicity of liquid slag,different temperatures,and different holding times.The results indicate that as basicity of slag increases from 0.52 to 1.03,temperature increases from 1423 to 1573 K,the viscosity of slag decreases,the floating rate of bubbles increases.In addition,when holding time increases from 10 to 30 s,the bubbles floating distance increases,and the volume fraction and average equivalent sphere diameter of the bubbles solidified in the mold flux gradually decreases.In one word,increasing the basicity,temperature,and holding time leading to an increase in the removal rate of bubbles especially for the large.These findings of bubbles escape behavior provide valuable insights into optimizing low basicity mold flux for high-Mn high-Al steels.
基金Supported by Major Project of School-level Teaching Reform and Research of Guangxi University of Chinese Medicine(2022A006)。
文摘In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly efficacious approach to enhance the teaching level of experimental courses in medicinal botany.The implementation of a digital microscope mutual system in experimental teaching not only enhances students practical skills in laboratory operations but also increases classroom efficiency.Furthermore,it supports personalized development among students while fostering innovative thinking,independent learning capabilities,and analysis and problem-solving skills.Additionally,this approach contributes to the enhancement of students scientific literacy.
基金supports from the National Natural Science Foundation of China(Grant No.52474059,Grant No.52174046)are greatly acknowledged.
文摘Fine particle detachment and subsequent migration can lead to severe pore plugging and consequent permeability decline.Therefore,it is crucial to quantify the critical condition when fine particle detachment occurs.The frequently observed deviations or even contradictions between experimental results and theoretical predictions of fines detachment arise from an insufficient understanding of adhesion force that can be highly influenced by salinity and temperature.To clarify the intrinsic influence of salinity and temperature on fines detachment,adhesion forces between carboxyl microspheres and hydrophilic silica substrates in an aqueous medium were measured at various salinities and tempera-tures using atomic force microscopy(AFM).The AFM-measured adhesion force decreases with increasing salinity or temperature.Trends of mean measured adhesion forces with temperature and salinity were compared with the DLVO and XDLVO theories.DLVO theory captured the trend with temperature via the impact of temperature on electric double layer interactions,whereas XDLVO theory captured the observed trend with salinity via the impact of salinity on the repulsive hydration force.Our results highlight the significance of hydration force in accurately predicting the fate of fines in porous media.
基金Supported by National Nature Science Foundation of China(Grant Nos.52205225,U2330202)The Foundation Project of China(Grant No.2023-JCJQ-JJ-0958).
文摘With the intensification of lunar exploration,the failure risk caused by the adsorption of lunar dust on the spacecraft surface cannot be ignored.Therefore,three types of typical spatial solid lubrication films,namely polytetrafluoroethylene(PTFE),amorphous carbon(a-C)and molybdenum disulfide(MoS2),were prepared as test samples.Firstly,the surface free energy parameters of the material were measured using a contact Angle measuring instrument.At the same time,atomic force microscopy(AFM)was used to quantify the adhesion of the film samples based on the lunar dust micro-adsorption model.In order to investigate the influence of the test environment,the environmental pressure was adjusted to normal pressure environment and high vacuum environment with a vacuum degree of 10−6 Pa for testing.The results indicate a positive correlation between surface energy and adhesion.As surface energy increases,molecules tend to move closer,forming a stronger attraction and thus enhancing surface adhesion.In addition,AFM was used to measure the adhesion force under atmospheric pressure and vacuum conditions,revealing that parameters measured in atmospheric environment were generally higher than those measured in vacuum,which effectively verified the existence of capillary force in the microscopic adsorption model and its influence on the adhesion effect.Through the test comparison of three groups of typical solid lubricating films,it is found that MoS2 has a lower adhesion effect than the other two groups of films,which can effectively reduce the adhesion phenomenon of lunar dust on the surface of the material,and provide suitable materials for future lunar exploration and manned lunar missions.
基金supported by the National Natural Science Foundation of China(Grant Nos.52274339,52174321,52074186,and 52104337)Natural Science Foundation of Jiangsu Province(Grant No.BK20231317)China Baowu Low-Carbon Metallurgy Innovation Fund(Grant No.BWLCF202108).
文摘To investigate the nucleation behavior during the single-phased metallic solidification process,the commercial ultrapure ferritic stainless steels with no(Initial steel)and various melt treatments(R1,MR1,Y2,MY1,and M1 steels)were used to carry out the differential scanning colorimetry(DSC)and high-temperature confocal laser scanning microscope(HT-CLSM)experiments.Based on the results of DSC experiments,the equilibrium solidification process as well as the relationship among the critical undercooling degree(△T_(c)^(DSC)),latent heat of fusion/crystallization(△H_(f)/△H_(c)),equiaxed grain ratio(ER),and average grain size(△_(ave)^(ingot))was revealed.ER is increased with the decreasing△T_(c)^(DSC)and increasing△H_(f)/△H_(c);however,△_(ave)^(ingot)is decreased with them.Referring to the results of HT-CLSM experiments,the average sizes of micro-/macrostructures(d_(ave)/D_(ave)/)are decreased with the increasing cooling rate,as well as the difference between and apparent critical undercooling degree(△T_(c)^(CLSM))was revealed.The heterogeneous nucleation of the crystal nuclei occurs only if△T_(c)^(CLSM)>△T_(c)^(DSC).Combining with the interfacial wetting-lattice mismatch heterogeneous nucleation model,the dynamic mechanism of the metallic solidification was revealed.The as-cast grains of the melt-treated samples were obviously refined,owing to the much higher actual heterogeneous nucleation rates(I_(heter.,i))obtained through melt treatments,and the heterogeneous nucleation rates(I_(heter.,ij))for all samples are increased with the cooling rates,firmly confirming that the as-cast grains of each sample could be refined by the increasing cooling rates.
