Nanobubble flotation technology is an important research topic in the field of fine mineral particle separation.The basic characteristics of nanobubbles,including their size,concentration,surface zeta potential,and st...Nanobubble flotation technology is an important research topic in the field of fine mineral particle separation.The basic characteristics of nanobubbles,including their size,concentration,surface zeta potential,and stability have a significant impact on the nanobubble flotation performance.In this paper,bulk nanobubbles generated based on the principle of hydrodynamic cavitation were investigated to determine the effects of different parameters(e.g.,surfactant(frother)dosage,air flow,air pressure,liquid flow rate,and solution pH value)on their size distribution and zeta potential,as measured using a nanoparticle analyzer.The results demonstrated that the nanobubble size decreased with increasing pH value,surfactant concentration,and cavitation-tube liquid flow rate but increased with increasing air pressure and increasing air flow rate.The magnitude of the negative surface charge of the nanobubbles was positively correlated with the pH value,and a certain relationship was observed between the zeta potential of the nanobubbles and their size.The structural parameters of the cavitation tube also strongly affected the characteristics of the nanobubbles.The results of this study offer certain guidance for optimizing the nanobubble flotation technology.展开更多
Particle size distributions （PSDs） of bottom sediments in a coastal zone are generally multimodal due to the complexity of the dynamic environment. In this paper, bottom sediments along the deep channel of the Pearl...Particle size distributions （PSDs） of bottom sediments in a coastal zone are generally multimodal due to the complexity of the dynamic environment. In this paper, bottom sediments along the deep channel of the Pearl River Estuary （PRE） are used to understand the multimodal PSDs＇ characteristics and the corresponding depositional environment. The results of curve-fitting analysis indicate that the near-bottom sediments in the deep channel generally have a bimodal distribution with a fine component and a relatively coarse component. The particle size distribution of bimodal sediment samples can be expressed as the sum of two lognormal functions and the parameters for each component can be determined. At each station of the PRE, the fine component makes up less volume of the sediments and is relatively poorly sorted. The relatively coarse component, which is the major component of the sediments, is even more poorly sorted. The interrelations between the dynamics and particle size of the bottom sediment in the deep channel of the PRE have also been investigated by the field measurement and simulated data. The critical shear velocity and the shear velocity are calculated to study the stability of the deep channel. The results indicate that the critical shear velocity has a similar distribution over large part of the deep channel due to the similar particle size distribution of sediments. Based on a comparison between the critical shear velocities derived from sedimentary parameters and the shear velocities obtained by tidal currents, it is likely that the depositional area is mainly distributed in the northern part of the channel, while the southern part of the deep channel has to face higher erosion risk.展开更多
This study explored the potential of polysaccharides from Actium lappa(ALPs)as natural wall materials for producing ALP-based nanoparticles to deliver poorly water-soluble oleanolic acid(OA)and ursolic acid(UA).Encaps...This study explored the potential of polysaccharides from Actium lappa(ALPs)as natural wall materials for producing ALP-based nanoparticles to deliver poorly water-soluble oleanolic acid(OA)and ursolic acid(UA).Encapsulating OA+UA with ALPs(ALP:OA+UA,50:1;OA:UA,1:1)changed the crystalline nature to a more amorphous state through hydrogen bonding and involving O-H/C-O/O-C-O groups.ALP-OA/UA nanoparticles had a particle size and zeta potential(in water)of 199.1 nm/-7.15 mV,with a narrow unimodal size distribution,and excellent pH,salt solution,temperature and storage stability.Compared with ALPs,ALPOA/UA nanoparticles showed enhanced anti-inflammatory activity(especially at a dose of 100μg/mL)in a CuSO-induced zebrafish inflammation model via down-regulating the NF-κB signalling pathway and gene expression of associated transcription factors and cytokines(TNF-α,IL-1βand IL-8).Therefore,ALP-based nanoparticles are natural and anti-inflammatory carriers for hydrophobic bioactive molecules.展开更多
对不同品种大豆分离蛋白(soybean protein isolate,SPI)的表面疏水性、氨基酸组成及溶液的Zeta电位和粒径分布进行分析,探讨蛋白质溶液Zeta电位和粒径分布与表面疏水性的关系。不同品种SPI的表面疏水性由大到小的变化趋势为:东农46>...对不同品种大豆分离蛋白(soybean protein isolate,SPI)的表面疏水性、氨基酸组成及溶液的Zeta电位和粒径分布进行分析,探讨蛋白质溶液Zeta电位和粒径分布与表面疏水性的关系。不同品种SPI的表面疏水性由大到小的变化趋势为:东农46>皖豆24>黑农46>五星4>中黄13>冀NF58,品种差异对SPI的Zeta电位及粒径分布具有显著影响。相关性分析表明,SPI表面疏水性与氨基酸组成无显著相关性,表面疏水性与Zeta电位绝对值呈显著的正相关,与粒径大小呈显著的负相关。当蛋白溶液Zeta电位绝对值较大时,蛋白表面更多同性电荷间的排斥作用会减少蛋白分子的相互聚集,使蛋白溶液趋于稳定,同时降低蛋白质粒径大小。此时,蛋白质疏水基团的内卷程度降低,并更多暴露在分子表面,导致蛋白质表面疏水性增加。展开更多
Emulsion prepared under acidic conditions was compared with emulsion prepared under basic conditions.Under acidic conditions emulsion had a small average count rate,emulsion particles grow slowly at the early stage an...Emulsion prepared under acidic conditions was compared with emulsion prepared under basic conditions.Under acidic conditions emulsion had a small average count rate,emulsion particles grow slowly at the early stage and grow quickly at the latter,the Zeta potential was low.However,under basic conditions,those parameters were contrasted.At the same time there was a plateau range in which particles almost would not grow.展开更多
This paper focuses on preparation of colloidal solution of graphene-like structures from different ranks of coals: brown coal,bituminous coal,low-volatile bituminous coal,anthracite. It was found that brown coal therm...This paper focuses on preparation of colloidal solution of graphene-like structures from different ranks of coals: brown coal,bituminous coal,low-volatile bituminous coal,anthracite. It was found that brown coal thermo-oxidative destruction leads to formation of small d = 32 nm( V = 17%) and large d = 122 nm( V = 11%) fractions of nanoparticles. The thermo-oxidative destruction of bituminous coal leads to formation of nanoparticles d = 50 nm( V = 5.2%) and d = 164 nm( V = 16%). Thermooxidative destruction of low-volatile bituminous coal and anthracite leads to formation of nanoparticles,predominantly,d = 122-190 nm. Carbon nanostructures obtained from coal are negatively charged at pH= 2-12. Colloidal solution of carbon nanostructures at dispersed phase concentration 0. 01 mg/mL is stable for 1 month. Electron diffraction patterns and X-ray analysis of carbon nanostructures showed that nanostructure from brown coal is amorphous and nanostructure from anthracite is crystalline. Results of coal macromolecules modeling and graphene-like structures obtained from them are presented.展开更多
文摘Nanobubble flotation technology is an important research topic in the field of fine mineral particle separation.The basic characteristics of nanobubbles,including their size,concentration,surface zeta potential,and stability have a significant impact on the nanobubble flotation performance.In this paper,bulk nanobubbles generated based on the principle of hydrodynamic cavitation were investigated to determine the effects of different parameters(e.g.,surfactant(frother)dosage,air flow,air pressure,liquid flow rate,and solution pH value)on their size distribution and zeta potential,as measured using a nanoparticle analyzer.The results demonstrated that the nanobubble size decreased with increasing pH value,surfactant concentration,and cavitation-tube liquid flow rate but increased with increasing air pressure and increasing air flow rate.The magnitude of the negative surface charge of the nanobubbles was positively correlated with the pH value,and a certain relationship was observed between the zeta potential of the nanobubbles and their size.The structural parameters of the cavitation tube also strongly affected the characteristics of the nanobubbles.The results of this study offer certain guidance for optimizing the nanobubble flotation technology.
基金supported by the National Natural Science Foundation of China(Grant Nos.41676078,51409088 and41506100)the Natural Science Foundation of Jiangsu Province(Grant No.BK20151499)+1 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.2015B16114,2015B26414 and 2015B34914)the Project of Jiangsu Provincial Six Talent Peaks(Grant No.XXRJ-008)
文摘Particle size distributions （PSDs） of bottom sediments in a coastal zone are generally multimodal due to the complexity of the dynamic environment. In this paper, bottom sediments along the deep channel of the Pearl River Estuary （PRE） are used to understand the multimodal PSDs＇ characteristics and the corresponding depositional environment. The results of curve-fitting analysis indicate that the near-bottom sediments in the deep channel generally have a bimodal distribution with a fine component and a relatively coarse component. The particle size distribution of bimodal sediment samples can be expressed as the sum of two lognormal functions and the parameters for each component can be determined. At each station of the PRE, the fine component makes up less volume of the sediments and is relatively poorly sorted. The relatively coarse component, which is the major component of the sediments, is even more poorly sorted. The interrelations between the dynamics and particle size of the bottom sediment in the deep channel of the PRE have also been investigated by the field measurement and simulated data. The critical shear velocity and the shear velocity are calculated to study the stability of the deep channel. The results indicate that the critical shear velocity has a similar distribution over large part of the deep channel due to the similar particle size distribution of sediments. Based on a comparison between the critical shear velocities derived from sedimentary parameters and the shear velocities obtained by tidal currents, it is likely that the depositional area is mainly distributed in the northern part of the channel, while the southern part of the deep channel has to face higher erosion risk.
基金supported by the Shandong Provincial Natural Science Foundation of China(ZR2019BC100)Science,Education and Industry Integration Innovation Pilot Project of Qilu University of Technology(Shandong Academy of Sciences)(2020KJC-ZD10)Incubation Program of Youth Innovation in Shandong Province。
文摘This study explored the potential of polysaccharides from Actium lappa(ALPs)as natural wall materials for producing ALP-based nanoparticles to deliver poorly water-soluble oleanolic acid(OA)and ursolic acid(UA).Encapsulating OA+UA with ALPs(ALP:OA+UA,50:1;OA:UA,1:1)changed the crystalline nature to a more amorphous state through hydrogen bonding and involving O-H/C-O/O-C-O groups.ALP-OA/UA nanoparticles had a particle size and zeta potential(in water)of 199.1 nm/-7.15 mV,with a narrow unimodal size distribution,and excellent pH,salt solution,temperature and storage stability.Compared with ALPs,ALPOA/UA nanoparticles showed enhanced anti-inflammatory activity(especially at a dose of 100μg/mL)in a CuSO-induced zebrafish inflammation model via down-regulating the NF-κB signalling pathway and gene expression of associated transcription factors and cytokines(TNF-α,IL-1βand IL-8).Therefore,ALP-based nanoparticles are natural and anti-inflammatory carriers for hydrophobic bioactive molecules.
文摘对不同品种大豆分离蛋白(soybean protein isolate,SPI)的表面疏水性、氨基酸组成及溶液的Zeta电位和粒径分布进行分析,探讨蛋白质溶液Zeta电位和粒径分布与表面疏水性的关系。不同品种SPI的表面疏水性由大到小的变化趋势为:东农46>皖豆24>黑农46>五星4>中黄13>冀NF58,品种差异对SPI的Zeta电位及粒径分布具有显著影响。相关性分析表明,SPI表面疏水性与氨基酸组成无显著相关性,表面疏水性与Zeta电位绝对值呈显著的正相关,与粒径大小呈显著的负相关。当蛋白溶液Zeta电位绝对值较大时,蛋白表面更多同性电荷间的排斥作用会减少蛋白分子的相互聚集,使蛋白溶液趋于稳定,同时降低蛋白质粒径大小。此时,蛋白质疏水基团的内卷程度降低,并更多暴露在分子表面,导致蛋白质表面疏水性增加。
文摘Emulsion prepared under acidic conditions was compared with emulsion prepared under basic conditions.Under acidic conditions emulsion had a small average count rate,emulsion particles grow slowly at the early stage and grow quickly at the latter,the Zeta potential was low.However,under basic conditions,those parameters were contrasted.At the same time there was a plateau range in which particles almost would not grow.
基金supported by the Ministry of Education and Science of the Russian Federation(the Agreement number 02.a03.21.0008)
文摘This paper focuses on preparation of colloidal solution of graphene-like structures from different ranks of coals: brown coal,bituminous coal,low-volatile bituminous coal,anthracite. It was found that brown coal thermo-oxidative destruction leads to formation of small d = 32 nm( V = 17%) and large d = 122 nm( V = 11%) fractions of nanoparticles. The thermo-oxidative destruction of bituminous coal leads to formation of nanoparticles d = 50 nm( V = 5.2%) and d = 164 nm( V = 16%). Thermooxidative destruction of low-volatile bituminous coal and anthracite leads to formation of nanoparticles,predominantly,d = 122-190 nm. Carbon nanostructures obtained from coal are negatively charged at pH= 2-12. Colloidal solution of carbon nanostructures at dispersed phase concentration 0. 01 mg/mL is stable for 1 month. Electron diffraction patterns and X-ray analysis of carbon nanostructures showed that nanostructure from brown coal is amorphous and nanostructure from anthracite is crystalline. Results of coal macromolecules modeling and graphene-like structures obtained from them are presented.
