Ammonium pollution becomes severe during mining of ionic rare earth-ores in southern China.As one of the main clayminerals in soils of ionic rare earth mines,halloysite plays an important role in ammonium adsorption.I...Ammonium pollution becomes severe during mining of ionic rare earth-ores in southern China.As one of the main clayminerals in soils of ionic rare earth mines,halloysite plays an important role in ammonium adsorption.In this study,the saturatedadsorption capacity,factors affecting adsorption and adsorption kinetics of halloysite for ammonium were investigated.The resultsindicated that the ammonium adsorption of halloysite was saturated with1.66mg/g at303K,pH of5.6and initial ammoniumconcentration of600mg/L(about half of the actual initial in-situ leaching concentration).When the initial concentration of NH4?-N,pH values and temperatures(288K to313K)increased,the ammonium adsorption capacity of halloysite increased.The ammoniumisothermal adsorption of halloysite matched the Langmuir and Freundlich isotherms.The adsorption process of ionic rare earthmining soils for ammonium was favorable.And the adsorption process followed closely the pseudo-second kinetic equation.展开更多
Halloysite nanotube-composited thermo-responsive hydrogel system has been successfully developed for controlled drug release by copolymerization of N-isopropylacrylamide （NIPAM） with silane-modified halloysite nanot...Halloysite nanotube-composited thermo-responsive hydrogel system has been successfully developed for controlled drug release by copolymerization of N-isopropylacrylamide （NIPAM） with silane-modified halloysite nanotubes （HNT） through thermally initiated free-radical polymerization. With methylene blue as a model drug, thermo-responsive drug release results demonstrate that the drug release from the nanotubes in the composited hy-drogel can^be well controlled by manipulating the environmental temperature. When the hydrogel network is swol- len at temperature below the lower critical solution temperature （LCST）, drug releases steadily from lumens of the embedded nanotubes, whereas the drug release stops when hydrogel shrinks at temperature above the LCST. The release of model drug from the HNT-composited hydrogel matches well with its thermo-responsive volume phasetransition, and shows characteristics of well controlled release. The design strategy and release results of the pro- posed novel HNT-composited thermo-responsive hydrogel system provide valuable guidance for designing respon- s_i_ve nanocomposites for controlled-release of active agents.展开更多
The N-doped TiO2-loaded halloysite nanotubes(N-Ti O2/HNTs) nanocomposites were prepared by using chemical vapor deposition method which was realized in autoclave. The photocatalytic activity of nanocomposites was eval...The N-doped TiO2-loaded halloysite nanotubes(N-Ti O2/HNTs) nanocomposites were prepared by using chemical vapor deposition method which was realized in autoclave. The photocatalytic activity of nanocomposites was evaluated by virtue of the decomposition of formaldehyde gas under solar-light irradiation. The XRD patterns verified that the anatase structured TiO2 was deposited on HNTs. The TEM images showed that the surface of HNTs was covered with nanosized TiO2 with a particle size of ca. 20 nm. The UV-vis spectra indicated that the N-Ti O2/HNTs presented a significant absorption band in the visible region between 400 nm and 600 nm. Under solar-light irradiation, the highest degradation rate of formaldehyde gas attained 90% after 100 min of solar-light irradiation. The combination of the photocatalytic property of TiO2 and the unique structure of halloysite would assert a promising perspective in degradation of organic pollutants.展开更多
The main results of hydrocracking of goudron under reduced pressure in the presence of a suspended catalyst have been analyzed. It was investigated the influence of pressure to hydrocracking process of goudron. It was...The main results of hydrocracking of goudron under reduced pressure in the presence of a suspended catalyst have been analyzed. It was investigated the influence of pressure to hydrocracking process of goudron. It was determined that with increasing from 0.5 to 4.0 MPa, the yield of light oil products increased from 47% to 58% mass.展开更多
In this study, the adsorption of o-xylene was investigated using modified halloysite adsorbents. The modification of the halloysite adsorbents depended on thermal processing, treated sulphuric acid（Vl） and sodium hy...In this study, the adsorption of o-xylene was investigated using modified halloysite adsorbents. The modification of the halloysite adsorbents depended on thermal processing, treated sulphuric acid（Vl） and sodium hydroxide, water solution of ammonium chloride as well as hexadecylotrimethyloammonium bromide. Adsorption rate constants of the pseudo-second order models were compared for experiment carried in the batch system. Langmuir and Freundlich to fit the adsorption equilibrium experimental data. pseudo-first and models were able展开更多
Chemically modified halloysite proved to be an effective adsorbent for the pesticide chlorpropham and 3-chloroaniline from an aqueous solution. Adsorption experiments were conducted using such procedures as the time-d...Chemically modified halloysite proved to be an effective adsorbent for the pesticide chlorpropham and 3-chloroaniline from an aqueous solution. Adsorption experiments were conducted using such procedures as the time-dependent （kinetic） procedure and the concentration dependent （isotherm） procedure. Results indicate that the adsorption process is related to the kind of the studied compound. The equilibrium data are well suited to a Freundlich isotherm in the case of both investigated compounds. Adsorption kinetics of chlorpropham and 3-chloroaniline on acid-treated halloysite was successfully described by pseudo-second order kinetic model and the model of Weber and Morris. From the present study, we suggest that the adsorption of chlorpropham and 3-chloroaniline on the modified halloysite is a rather complex process involving two steps： external mass transfer and intra-particle diffusion.展开更多
The Pomegranate （Punica Granatum）, which belongs tothe Lythraceae family, has been used for centuries in traditional Greco-Arab and Islamic medicine of its vermifuge properties and also to treat various diseases. Th...The Pomegranate （Punica Granatum）, which belongs tothe Lythraceae family, has been used for centuries in traditional Greco-Arab and Islamic medicine of its vermifuge properties and also to treat various diseases. The aim of this research was to investigate the cytotoxicity and antioxidant activities of Moroccan Pomegranate （peel, leaves, branches, flowers and corolla）. Further, the biological activities were correlated with phytochemical contents of the plant extracts. Methanolic extract from different parts of Punica Granatum was assessed for its antiproliferative activity in two human cancer （breast and colon） cells lines （MBA-MD 231 and HT-29）, through MTT （3-（4,5-dimethyl-2- thiazolyl）-2,5-diphenyl-2H-tetrazolium bromide） bioassay using cell viability and cytotoxicity indices. DPPH （2,2-diphenyl-l-picrylhydrazyl） assay was conducted to screen the antioxidant property of the extracts together with its phenolic and flavonoids content were evaluated, as well. The methanolic extract ofPunica Granatum （peel, leaves, branches, flowers and corolla） showed the highest antiproliferative activity on MBA-MD 231 （IC50 was 133.53-233.32 μg/mL） and HT-29 （IC50 was 127.58-203.24 μg/mL） cells. Antioxidants contents are distributed as follows： peel 〉 leaf 〉 flower 〉 corolla 〉 branches. The inhibitory activities required for decreasing initial DPPH by 50% are 8.27, 9.9, 10.06, 11.67 and 13.28 μg/mL, respectively. These results are in correlation with polyphenols content from corolla, peel, leaves, flower and branches are 120.7, 115, 96.65, 90.73 and 64.67 mg GAE/g dw （mg gallic acid equivalents per g dry weight） and flavonoids are 188.8, 221.7, 180.2, 193.7 and 158.5 mg QE/g dw （mg quercetin equivalents per g dry weight）. Our results show that the peel, flowers, corolla, leaves and branches of Moroccan Pomegranate may contain a lot of bioactive compounds which are responsible for strong antioxidant and cytotoxicity activities observed here. Our finding indicates the possibility of using the extracts of this plant as source of natural antioxidant and anticancer mainly for its abundant phenolic and flavonoid contents.展开更多
In this study, the thermal expansion and heat capacity of San Carlos olivine under high temperature and high pressure are reported. Combining accurate sound velocity data under different P–T conditions with density a...In this study, the thermal expansion and heat capacity of San Carlos olivine under high temperature and high pressure are reported. Combining accurate sound velocity data under different P–T conditions with density and heat capacity data at ambient pressure, the density,adiabatic bulk modulus, shear modulus, and most importantly, thermal expansion and heat capacity, of San Carlos are extracted to 14 GPa by a numerical procedure using classic thermodynamic relationships. These data are in agreement with published findings. To estimate the temperature gradient in the upper mantle, we also report the fitting equations of thermal expansion and heat capacity of San Carlos olivine as a function of both temperature and pressure to the P–T condition of the 410 km discontinuity,which provide the thermodynamic properties with increasing depth in the Earth's interior.展开更多
Andalusite rich schist until now has not been utilized to produce refractory. In this work, refractory materials were elaborated from alumina-silica geomaterials related to granitoids and their direct surrounding roc...Andalusite rich schist until now has not been utilized to produce refractory. In this work, refractory materials were elaborated from alumina-silica geomaterials related to granitoids and their direct surrounding rocks （kaolin clay and andalusite fiche schist）. Characterization evolution on heating was investigated in a composition （80% kaolinitic clay, 20% andalusite rich schist）. The evolution of mullite was examined by SEM （scanning electron microscopy） and XRD （X-ray diffraction）. The thermal shock test showed that the refractory sample has a good thermal shock resistance.展开更多
Long-term air contamination and pollution challenges in particulate matter(PM) have raised fervent concerns for public health, e.g., the PM physical damage or the bacteria and virus carried by the PM. The desired air ...Long-term air contamination and pollution challenges in particulate matter(PM) have raised fervent concerns for public health, e.g., the PM physical damage or the bacteria and virus carried by the PM. The desired air filter, seeking both high filtration efficiency and low pressure drop remains challenging. Here, we report a bio-inspired spindle-knot halloysite nanotube microsphere-incorporated nanofiber(HNM-NF) filter with the assembly and shape structures of the spider silk. The resulting HNM-NFs exhibit integrated properties of high surface energy, hydrophilicity and strong PM capture. The spindle-knot structures could shrink the outer pore size on two-dimensional(2 D) surface and construct the fluffy 3 D reticular architecture, facilitating high-efficiency air pollutant capture(>85.0%) while maintaining low resistance to airflow(~39 Pa). The spindle-knot construction method was applicable to various materials(i.e.,Al_(2)O_(3), ZnO and TiO_(2)) and volume production of the microsphere-incorporated NF cartridge. The diversified spindleknot construction will be valuable for adapting to meet different filtration requirements.展开更多
基金Project(51674305)supported by the National Natural Science Foundation of ChinaProject(1602FKDC007)supported by Science and Technology Program of Gansu Province,ChinaProject(NSFJ2015-K06)supported by the Jiangxi University of Science and Technology,China
文摘Ammonium pollution becomes severe during mining of ionic rare earth-ores in southern China.As one of the main clayminerals in soils of ionic rare earth mines,halloysite plays an important role in ammonium adsorption.In this study,the saturatedadsorption capacity,factors affecting adsorption and adsorption kinetics of halloysite for ammonium were investigated.The resultsindicated that the ammonium adsorption of halloysite was saturated with1.66mg/g at303K,pH of5.6and initial ammoniumconcentration of600mg/L(about half of the actual initial in-situ leaching concentration).When the initial concentration of NH4?-N,pH values and temperatures(288K to313K)increased,the ammonium adsorption capacity of halloysite increased.The ammoniumisothermal adsorption of halloysite matched the Langmuir and Freundlich isotherms.The adsorption process of ionic rare earthmining soils for ammonium was favorable.And the adsorption process followed closely the pseudo-second kinetic equation.
基金Supported by the National ]qatural Science Foundation of China （20906064）, the National Basic Research Program of China （2009CB623407）, the Program for Changjiang Scholars and Innovative Research Team in University （IRTl163）, and the Foundation for the Author of National Excellent Doctoral Dissertation of China （201163）.
文摘Halloysite nanotube-composited thermo-responsive hydrogel system has been successfully developed for controlled drug release by copolymerization of N-isopropylacrylamide （NIPAM） with silane-modified halloysite nanotubes （HNT） through thermally initiated free-radical polymerization. With methylene blue as a model drug, thermo-responsive drug release results demonstrate that the drug release from the nanotubes in the composited hy-drogel can^be well controlled by manipulating the environmental temperature. When the hydrogel network is swol- len at temperature below the lower critical solution temperature （LCST）, drug releases steadily from lumens of the embedded nanotubes, whereas the drug release stops when hydrogel shrinks at temperature above the LCST. The release of model drug from the HNT-composited hydrogel matches well with its thermo-responsive volume phasetransition, and shows characteristics of well controlled release. The design strategy and release results of the pro- posed novel HNT-composited thermo-responsive hydrogel system provide valuable guidance for designing respon- s_i_ve nanocomposites for controlled-release of active agents.
基金supported by the Talent Introduction Fund of Yangzhou Universitythe Jiangsu Social Development Project(BE2014613)the Six Talent Peaks of Jiangsu province(2014-XCL-013)
文摘The N-doped TiO2-loaded halloysite nanotubes(N-Ti O2/HNTs) nanocomposites were prepared by using chemical vapor deposition method which was realized in autoclave. The photocatalytic activity of nanocomposites was evaluated by virtue of the decomposition of formaldehyde gas under solar-light irradiation. The XRD patterns verified that the anatase structured TiO2 was deposited on HNTs. The TEM images showed that the surface of HNTs was covered with nanosized TiO2 with a particle size of ca. 20 nm. The UV-vis spectra indicated that the N-Ti O2/HNTs presented a significant absorption band in the visible region between 400 nm and 600 nm. Under solar-light irradiation, the highest degradation rate of formaldehyde gas attained 90% after 100 min of solar-light irradiation. The combination of the photocatalytic property of TiO2 and the unique structure of halloysite would assert a promising perspective in degradation of organic pollutants.
文摘The main results of hydrocracking of goudron under reduced pressure in the presence of a suspended catalyst have been analyzed. It was investigated the influence of pressure to hydrocracking process of goudron. It was determined that with increasing from 0.5 to 4.0 MPa, the yield of light oil products increased from 47% to 58% mass.
文摘In this study, the adsorption of o-xylene was investigated using modified halloysite adsorbents. The modification of the halloysite adsorbents depended on thermal processing, treated sulphuric acid（Vl） and sodium hydroxide, water solution of ammonium chloride as well as hexadecylotrimethyloammonium bromide. Adsorption rate constants of the pseudo-second order models were compared for experiment carried in the batch system. Langmuir and Freundlich to fit the adsorption equilibrium experimental data. pseudo-first and models were able
文摘Chemically modified halloysite proved to be an effective adsorbent for the pesticide chlorpropham and 3-chloroaniline from an aqueous solution. Adsorption experiments were conducted using such procedures as the time-dependent （kinetic） procedure and the concentration dependent （isotherm） procedure. Results indicate that the adsorption process is related to the kind of the studied compound. The equilibrium data are well suited to a Freundlich isotherm in the case of both investigated compounds. Adsorption kinetics of chlorpropham and 3-chloroaniline on acid-treated halloysite was successfully described by pseudo-second order kinetic model and the model of Weber and Morris. From the present study, we suggest that the adsorption of chlorpropham and 3-chloroaniline on the modified halloysite is a rather complex process involving two steps： external mass transfer and intra-particle diffusion.
文摘The Pomegranate （Punica Granatum）, which belongs tothe Lythraceae family, has been used for centuries in traditional Greco-Arab and Islamic medicine of its vermifuge properties and also to treat various diseases. The aim of this research was to investigate the cytotoxicity and antioxidant activities of Moroccan Pomegranate （peel, leaves, branches, flowers and corolla）. Further, the biological activities were correlated with phytochemical contents of the plant extracts. Methanolic extract from different parts of Punica Granatum was assessed for its antiproliferative activity in two human cancer （breast and colon） cells lines （MBA-MD 231 and HT-29）, through MTT （3-（4,5-dimethyl-2- thiazolyl）-2,5-diphenyl-2H-tetrazolium bromide） bioassay using cell viability and cytotoxicity indices. DPPH （2,2-diphenyl-l-picrylhydrazyl） assay was conducted to screen the antioxidant property of the extracts together with its phenolic and flavonoids content were evaluated, as well. The methanolic extract ofPunica Granatum （peel, leaves, branches, flowers and corolla） showed the highest antiproliferative activity on MBA-MD 231 （IC50 was 133.53-233.32 μg/mL） and HT-29 （IC50 was 127.58-203.24 μg/mL） cells. Antioxidants contents are distributed as follows： peel 〉 leaf 〉 flower 〉 corolla 〉 branches. The inhibitory activities required for decreasing initial DPPH by 50% are 8.27, 9.9, 10.06, 11.67 and 13.28 μg/mL, respectively. These results are in correlation with polyphenols content from corolla, peel, leaves, flower and branches are 120.7, 115, 96.65, 90.73 and 64.67 mg GAE/g dw （mg gallic acid equivalents per g dry weight） and flavonoids are 188.8, 221.7, 180.2, 193.7 and 158.5 mg QE/g dw （mg quercetin equivalents per g dry weight）. Our results show that the peel, flowers, corolla, leaves and branches of Moroccan Pomegranate may contain a lot of bioactive compounds which are responsible for strong antioxidant and cytotoxicity activities observed here. Our finding indicates the possibility of using the extracts of this plant as source of natural antioxidant and anticancer mainly for its abundant phenolic and flavonoid contents.
基金supported by the Strategic Priority Research Program (B) of Chinese Academy of Sciences (XDB 18010401)Light of the West Foundation of Chinese Academy of Sciences (Y5CR025000)
文摘In this study, the thermal expansion and heat capacity of San Carlos olivine under high temperature and high pressure are reported. Combining accurate sound velocity data under different P–T conditions with density and heat capacity data at ambient pressure, the density,adiabatic bulk modulus, shear modulus, and most importantly, thermal expansion and heat capacity, of San Carlos are extracted to 14 GPa by a numerical procedure using classic thermodynamic relationships. These data are in agreement with published findings. To estimate the temperature gradient in the upper mantle, we also report the fitting equations of thermal expansion and heat capacity of San Carlos olivine as a function of both temperature and pressure to the P–T condition of the 410 km discontinuity,which provide the thermodynamic properties with increasing depth in the Earth's interior.
文摘Andalusite rich schist until now has not been utilized to produce refractory. In this work, refractory materials were elaborated from alumina-silica geomaterials related to granitoids and their direct surrounding rocks （kaolin clay and andalusite fiche schist）. Characterization evolution on heating was investigated in a composition （80% kaolinitic clay, 20% andalusite rich schist）. The evolution of mullite was examined by SEM （scanning electron microscopy） and XRD （X-ray diffraction）. The thermal shock test showed that the refractory sample has a good thermal shock resistance.
基金supported by the National Natural Science Foundation of China (21878341,51804343,41572036 and 51225403)the Natural Science Foundation of Hunan Province(2018JJ3670)the Key R&D Program of Hunan Province(2017GK2251)。
文摘Long-term air contamination and pollution challenges in particulate matter(PM) have raised fervent concerns for public health, e.g., the PM physical damage or the bacteria and virus carried by the PM. The desired air filter, seeking both high filtration efficiency and low pressure drop remains challenging. Here, we report a bio-inspired spindle-knot halloysite nanotube microsphere-incorporated nanofiber(HNM-NF) filter with the assembly and shape structures of the spider silk. The resulting HNM-NFs exhibit integrated properties of high surface energy, hydrophilicity and strong PM capture. The spindle-knot structures could shrink the outer pore size on two-dimensional(2 D) surface and construct the fluffy 3 D reticular architecture, facilitating high-efficiency air pollutant capture(>85.0%) while maintaining low resistance to airflow(~39 Pa). The spindle-knot construction method was applicable to various materials(i.e.,Al_(2)O_(3), ZnO and TiO_(2)) and volume production of the microsphere-incorporated NF cartridge. The diversified spindleknot construction will be valuable for adapting to meet different filtration requirements.
