The experiments were conducted to investigate the behavior of airborne particles adhering to the glass slides which were coated by several reagent films. The results showed that the adhesion level could be significant...The experiments were conducted to investigate the behavior of airborne particles adhering to the glass slides which were coated by several reagent films. The results showed that the adhesion level could be significantly changed by the reagent films. There were no evident rules between the average size of particles and sampling time interval, the placing angle and reagent concentration. The average particle size on the surface coated by composite reagent (2-3 μm) was smaller than that on the single reagent coated surface, while the largest particle size (4-5 μm) was observed on the surface coated with the Tween 60. The experiment also demonstrated that the best adhesive performance was obtained on the surface which was coated with 0.5% SDBS and 0.5% fluorocarbon composite reagents. The experiment results indicated that each reagent had a certain optimum adhesive range to the particle. The composite reagents with different proportion of single reagents exhibited some particular physical and chemical properties, which could effectively change the adhesive performance between the solid surface and the particles.展开更多
As a key parameter for indicating the fraction of surface-reflected solar incident radiation, land surface albedo plays an important role in the Earth’s surface energy budget(SEB). Since the Sanjiang Plain has been s...As a key parameter for indicating the fraction of surface-reflected solar incident radiation, land surface albedo plays an important role in the Earth’s surface energy budget(SEB). Since the Sanjiang Plain has been severely affected by human activities(e.g., reclamation and shrinking of wetlands), it is important to assess the spatiotemporal variations of surface albedo in this region using a long-term remote sensing dataset. In order to investigate the surface albedo climatology, trends, and mechanisms of change, we evaluated the surface albedo variations in the Sanjiang Plain, China from 1982 to 2015 using the Global LAnd Surface Satellite(GLASS) broadband surface albedo product. The results showed that: 1) an increasing annual trend(+0.000 58/yr) of surface albedo was discovered in the Sanjiang Plain based on the GLASS albedo dataset, with a much stronger increasing trend(+0.001 26/yr) occurring during the winter. Most of the increasing trends occurred over the cultivated land, unused land, and land use conversion types located in the northeastern Sanjiang Plain. 2) The increasing trend of land surface albedo in Sanjiang Plain can be largely explained by the changes of both snow cover extent and land use. The surface albedo in winter is highly correlated with the snow cover extent in the Sanjiang Plain, and the increasing trend of surface albedo can be further enhanced by the land use changes.展开更多
In this study, it was examined whether the dynamics of polymer chains at a surface is different from that in thebulk, and if so, to what extent they differ in terms of surface glass transition temperature and diffusio...In this study, it was examined whether the dynamics of polymer chains at a surface is different from that in thebulk, and if so, to what extent they differ in terms of surface glass transition temperature and diffusion coefficient. Obtainedresults clearly indicate that surface chains can travel for a relatively large distance in comparison with the characteristiclength scale of usual segmental motion even at a temperature below its bulk glass transition temperature, T_g^b. This isconsistent with our previous results that the surface glass transition temperature is much lower than the corresponding T_g^b.Also, it was experimentally revealed that there was a gradient of molecular motion in the surface region.展开更多
K9 glass is a common material of optics and micro system, with cheaper price and better processing function. With the development of the optical and micro system, the technique of manufacturing micron/nanometer dimens...K9 glass is a common material of optics and micro system, with cheaper price and better processing function. With the development of the optical and micro system, the technique of manufacturing micron/nanometer dimensions microstructure and micro device on K9 glass has used in photoelectron, microwave and diffraction optics device et al The coarse surface of optics and microwave device can cause the light scattering and signal losing, and the function of device reduced. So the supersmooth surface plays an important role in optic and microwave device.展开更多
Effects of four kinds of triazine herbicides on the photodegradation of acetochlor were studied on glass surface and in aqueous solution under three kinds of light sources, i.e., xenon lamp, high pressure mercury lamp...Effects of four kinds of triazine herbicides on the photodegradation of acetochlor were studied on glass surface and in aqueous solution under three kinds of light sources, i.e., xenon lamp, high pressure mercury lamp and natural sunlight. The results indicated that atrazine, simetryne, prometryne and ametryne exhibited significant effects on the photoquenching degradation of acetochlor, and there was an obvious positive correlation between their effects and the dosage of four kinds of triazine herbicides.展开更多
The serrated plastic flow,microstructure and residual stress of a Zr_(55)Cu_(30)Ni_5Al_(10) bulk metallic glass(BMG)undergone surface mechanical attrition treatment(SMAT)have been investigated by a combinati...The serrated plastic flow,microstructure and residual stress of a Zr_(55)Cu_(30)Ni_5Al_(10) bulk metallic glass(BMG)undergone surface mechanical attrition treatment(SMAT)have been investigated by a combination of compression tests with scanning electron microscopy(SEM),high resolution transmission electron microscopy(HRTEM)and the incremental hole-drilling strain-gage method.It is found that SMAT leads to various microstructural modifications and residual stress distribution in the surface layers of the Zrbased BMG due to the mechanically-induced nanocrystallization and generation of shear bands.As a result,the BMG alloy exhibits a remarkable work-hardening like behavior and significant increase of plastic strain from less than 1%to 15%,and its plastic deformation dynamics yields a power-law distribution of shear avalanches.Based upon the analysis of the experimental results,it is indicated that this can be connected to the SMAT-induced microstructural modifications and the resulting residual compressive stress in the Zr-based BMG.展开更多
The surface of glass is crucial for understanding many fundamental processes in glassy solids.A common notion is that a glass surface is a thin layer with liquid-like atomic dynamics and a thickness of a few tens of n...The surface of glass is crucial for understanding many fundamental processes in glassy solids.A common notion is that a glass surface is a thin layer with liquid-like atomic dynamics and a thickness of a few tens of nanometers.Here,we measured the shear modulus at the surface of both millimeter-size and micrometer-size metallic glasses(MGs)through high-sensitivity torsion techniques.We found a pronounced shear-modulus softening at the surface of MGs.Compared with the bulk,the maximum decrease in the surface shear modulus(G)for the micro-scale MGs reaches~27%,which is close to the decrease in the G upon glass transition,yet it still behaves solid-like.Strikingly,the surface thickness estimated from the shear-modulus softening is at least 400 nm,which is approximately one order of magnitude larger than that revealed from the glass dynamics.The unusually thick surface is also confirmed by measurements using X-ray nano-computed tomography,and this may account for the brittle-to-ductile transition of the MGs with size reductions.The unique and unusual properties at the surface of the micrometer-size MGs are physically related to the negative pressure effect during the thermoplastic formation process,which can dramatically reduce the density of the proximate surface region in the supercooled liquid state.展开更多
Solid surface fluorescence (SSF) spectra of fibrinogen (FG) adsorbed on a glass surface were measured. For comparison, solution fluorescence (SF) spectra of native, thermally denatured, urea denatured FG solution wit...Solid surface fluorescence (SSF) spectra of fibrinogen (FG) adsorbed on a glass surface were measured. For comparison, solution fluorescence (SF) spectra of native, thermally denatured, urea denatured FG solution with FG desorbed from a glass surface and the SSF spectra of native FG powder were recorded. To analyze the structural changes induced by the surface adsorption, all the aqueous samples mentioned above were analyzed by circular dichroism (CD) spectroscopy. The results demonstrated that the structural changes of FG induced by glass adsorption caused changes in the spectroscopic features of the SSF spectra, especially in the excitation (EX) spectra. It is suggested that SSF spectroscopy may be a useful tool for studying the structures of surface/interface biomolecules and for evaluating the biocompatibility of biomaterials.展开更多
Mciro-arc oxidation(MAO)was used to coat porous films on the surface of a Zr-based bulk metallic glass sample.The compressive test results indicated that,compared with the as-cast sample,the MAO treated one exhibite...Mciro-arc oxidation(MAO)was used to coat porous films on the surface of a Zr-based bulk metallic glass sample.The compressive test results indicated that,compared with the as-cast sample,the MAO treated one exhibited higher deformation capacity,associated with multiple shear bands with higher density on the side surface and well-developed vein patterns with smaller size on the fractured surface.The pore in the MAOed film and the matrix/coating interface initiated the shear bands and impeded the rapid propagation of shear bands,thus favoring the enhanced plasticity of the MAO treated sample.The obtained results demonstrated that MAO can be considered as an effective method to finely tune the mechanical performance of monolithic bulk metallic glasses.展开更多
基金Project (50974132) supported by the National Natural Science Foundation of ChinaProject (2011QNZT094) supported by the Fundamental Research Funds for the Central Universities, China
文摘The experiments were conducted to investigate the behavior of airborne particles adhering to the glass slides which were coated by several reagent films. The results showed that the adhesion level could be significantly changed by the reagent films. There were no evident rules between the average size of particles and sampling time interval, the placing angle and reagent concentration. The average particle size on the surface coated by composite reagent (2-3 μm) was smaller than that on the single reagent coated surface, while the largest particle size (4-5 μm) was observed on the surface coated with the Tween 60. The experiment also demonstrated that the best adhesive performance was obtained on the surface which was coated with 0.5% SDBS and 0.5% fluorocarbon composite reagents. The experiment results indicated that each reagent had a certain optimum adhesive range to the particle. The composite reagents with different proportion of single reagents exhibited some particular physical and chemical properties, which could effectively change the adhesive performance between the solid surface and the particles.
基金the auspices of the National Key R&D Program of China(No.2016YFA0602301)National Natural Science Foundation of China(No.41971287,41601349)+1 种基金Science and Technology Development Program of Jilin Province(No.20180520220JH,20180623058TC)Fundamental Research Funds for the Central Universities(No.2412019FZ003)。
文摘As a key parameter for indicating the fraction of surface-reflected solar incident radiation, land surface albedo plays an important role in the Earth’s surface energy budget(SEB). Since the Sanjiang Plain has been severely affected by human activities(e.g., reclamation and shrinking of wetlands), it is important to assess the spatiotemporal variations of surface albedo in this region using a long-term remote sensing dataset. In order to investigate the surface albedo climatology, trends, and mechanisms of change, we evaluated the surface albedo variations in the Sanjiang Plain, China from 1982 to 2015 using the Global LAnd Surface Satellite(GLASS) broadband surface albedo product. The results showed that: 1) an increasing annual trend(+0.000 58/yr) of surface albedo was discovered in the Sanjiang Plain based on the GLASS albedo dataset, with a much stronger increasing trend(+0.001 26/yr) occurring during the winter. Most of the increasing trends occurred over the cultivated land, unused land, and land use conversion types located in the northeastern Sanjiang Plain. 2) The increasing trend of land surface albedo in Sanjiang Plain can be largely explained by the changes of both snow cover extent and land use. The surface albedo in winter is highly correlated with the snow cover extent in the Sanjiang Plain, and the increasing trend of surface albedo can be further enhanced by the land use changes.
基金This work was in part supported by a Gran-in-Aid for Scientific Research (A)(#13355034) from the Ministry of Education, Science, Sports, and Culture, Japan.
文摘In this study, it was examined whether the dynamics of polymer chains at a surface is different from that in thebulk, and if so, to what extent they differ in terms of surface glass transition temperature and diffusion coefficient. Obtainedresults clearly indicate that surface chains can travel for a relatively large distance in comparison with the characteristiclength scale of usual segmental motion even at a temperature below its bulk glass transition temperature, T_g^b. This isconsistent with our previous results that the surface glass transition temperature is much lower than the corresponding T_g^b.Also, it was experimentally revealed that there was a gradient of molecular motion in the surface region.
文摘K9 glass is a common material of optics and micro system, with cheaper price and better processing function. With the development of the optical and micro system, the technique of manufacturing micron/nanometer dimensions microstructure and micro device on K9 glass has used in photoelectron, microwave and diffraction optics device et al The coarse surface of optics and microwave device can cause the light scattering and signal losing, and the function of device reduced. So the supersmooth surface plays an important role in optic and microwave device.
文摘Effects of four kinds of triazine herbicides on the photodegradation of acetochlor were studied on glass surface and in aqueous solution under three kinds of light sources, i.e., xenon lamp, high pressure mercury lamp and natural sunlight. The results indicated that atrazine, simetryne, prometryne and ametryne exhibited significant effects on the photoquenching degradation of acetochlor, and there was an obvious positive correlation between their effects and the dosage of four kinds of triazine herbicides.
基金the financial supports provided by National Natural Science Foundation of China(Grant Nos.51171099,50871063)the MOST 973 Program of China(Grant Nos.2015CB856800 and 2012CB932203)
文摘The serrated plastic flow,microstructure and residual stress of a Zr_(55)Cu_(30)Ni_5Al_(10) bulk metallic glass(BMG)undergone surface mechanical attrition treatment(SMAT)have been investigated by a combination of compression tests with scanning electron microscopy(SEM),high resolution transmission electron microscopy(HRTEM)and the incremental hole-drilling strain-gage method.It is found that SMAT leads to various microstructural modifications and residual stress distribution in the surface layers of the Zrbased BMG due to the mechanically-induced nanocrystallization and generation of shear bands.As a result,the BMG alloy exhibits a remarkable work-hardening like behavior and significant increase of plastic strain from less than 1%to 15%,and its plastic deformation dynamics yields a power-law distribution of shear avalanches.Based upon the analysis of the experimental results,it is indicated that this can be connected to the SMAT-induced microstructural modifications and the resulting residual compressive stress in the Zr-based BMG.
基金This research was supported by the Guangdong Major Project of Basic and Applied Basic Research of China(grant no.2019B030302010)the National Key Research and Development Plan(grant nos.2018YFA0703603,2017YFB0903902,2016YFB0300501)+2 种基金the National Natural Science Foundation of China(grant no.51822107,11790291,61888102)the Strategic Priority Research Program of Chinese Academy of Sciences(grant no.XDB30000000)Beijing Municipal Science and Technology Commission(no.Z191100007219006).
文摘The surface of glass is crucial for understanding many fundamental processes in glassy solids.A common notion is that a glass surface is a thin layer with liquid-like atomic dynamics and a thickness of a few tens of nanometers.Here,we measured the shear modulus at the surface of both millimeter-size and micrometer-size metallic glasses(MGs)through high-sensitivity torsion techniques.We found a pronounced shear-modulus softening at the surface of MGs.Compared with the bulk,the maximum decrease in the surface shear modulus(G)for the micro-scale MGs reaches~27%,which is close to the decrease in the G upon glass transition,yet it still behaves solid-like.Strikingly,the surface thickness estimated from the shear-modulus softening is at least 400 nm,which is approximately one order of magnitude larger than that revealed from the glass dynamics.The unusually thick surface is also confirmed by measurements using X-ray nano-computed tomography,and this may account for the brittle-to-ductile transition of the MGs with size reductions.The unique and unusual properties at the surface of the micrometer-size MGs are physically related to the negative pressure effect during the thermoplastic formation process,which can dramatically reduce the density of the proximate surface region in the supercooled liquid state.
文摘Solid surface fluorescence (SSF) spectra of fibrinogen (FG) adsorbed on a glass surface were measured. For comparison, solution fluorescence (SF) spectra of native, thermally denatured, urea denatured FG solution with FG desorbed from a glass surface and the SSF spectra of native FG powder were recorded. To analyze the structural changes induced by the surface adsorption, all the aqueous samples mentioned above were analyzed by circular dichroism (CD) spectroscopy. The results demonstrated that the structural changes of FG induced by glass adsorption caused changes in the spectroscopic features of the SSF spectra, especially in the excitation (EX) spectra. It is suggested that SSF spectroscopy may be a useful tool for studying the structures of surface/interface biomolecules and for evaluating the biocompatibility of biomaterials.
基金the financial support from the National Natural Science Foundation of China(Grant Nos.51371065,51671070,51671067,51671071)the Opening Funding of AWJ-16-Z02 in the State Key Laboratory of Advanced Welding and Joining,China
文摘Mciro-arc oxidation(MAO)was used to coat porous films on the surface of a Zr-based bulk metallic glass sample.The compressive test results indicated that,compared with the as-cast sample,the MAO treated one exhibited higher deformation capacity,associated with multiple shear bands with higher density on the side surface and well-developed vein patterns with smaller size on the fractured surface.The pore in the MAOed film and the matrix/coating interface initiated the shear bands and impeded the rapid propagation of shear bands,thus favoring the enhanced plasticity of the MAO treated sample.The obtained results demonstrated that MAO can be considered as an effective method to finely tune the mechanical performance of monolithic bulk metallic glasses.