The activated carbon with high surface area was prepared by KOH activation.It was further modified by H2SO4 and HNO3 to introduce more surface functional groups.The pore structure of the activated carbons before and a...The activated carbon with high surface area was prepared by KOH activation.It was further modified by H2SO4 and HNO3 to introduce more surface functional groups.The pore structure of the activated carbons before and after modification was analyzed based on the nitrogen adsorption isotherms.The morphology of those activated carbons was characterized using scanning electronic microscopy （SEM）.The surface functional groups were determined by Fourier transform infrared spectroscopy （FTIR）.The quantity of those groups was measured by the Boehm titration method.Cr（VI） removal by the activated carbons from aqueous solution was investigated at different pH values.The results show that compared with H2SO4,HNO3 destructs the original pore of the activated carbon more seriously and induces more acidic surface functional groups on the activated carbon.The pH value of the solution plays a key role in the Cr（VI） removal.The ability of reducing Cr（VI） to Cr（III） by the activated carbons is relative to the acidic surface functional groups.At higher pH values,the Cr（VI） removal ratio is improved by increasing the acidic surface functional groups of the activated carbons.At lower pH values,however,the acidic surface functional groups almost have no effect on the Cr（VI） removal by the activated carbon from aqueous solution.展开更多
The low-melting phosphate glass was prepared for production of glass binders for protective coating of steel slab. Effects of different O/P ratios on glass structures and properties were analyzed. Differential thermal...The low-melting phosphate glass was prepared for production of glass binders for protective coating of steel slab. Effects of different O/P ratios on glass structures and properties were analyzed. Differential thermal analysis （DTA） and infrared spectroscopy （IR） techniques were applied for low-melting glass binder. It was found that the glass transition temperature（T） was about 300 ℃ and softening temperature（T1） was about 480 ℃. The choice of O/P ratio was very important to the glass transition and softening temperatures. When more P=O bonds existed in the glass networks, P-O-P bond angle was deformed with decreasing of the ratio of O/E The coatings could adhere to the substrates instantaneously at 800 ℃ when the content of binder exceeded 3wt%. The optimal content of glass binder was 5wt%.展开更多
1 Introduction In the present paper,MgCl2·6H2O,FeCl3·6H2O,and CeCl3·6H2O were used as raw materials in the precipitationhydrothermal method to synthesize MgF eC e hydrotalcite.The effects of the Fe:Ce m...1 Introduction In the present paper,MgCl2·6H2O,FeCl3·6H2O,and CeCl3·6H2O were used as raw materials in the precipitationhydrothermal method to synthesize MgF eC e hydrotalcite.The effects of the Fe:Ce molar ratio on the composition,crystal structure,and thermal stability of hydrotalcite are examined.Energy-dispersive X-ray spectroscopy(EDS),X-展开更多
China Cultural Center(CCC)in Hanoi,since its inauguration in 2017,has organized a great variety of performances and exhibitions to share China’s brilliant culture and gorgeous sceneries with Vietnamese,in particular,...China Cultural Center(CCC)in Hanoi,since its inauguration in 2017,has organized a great variety of performances and exhibitions to share China’s brilliant culture and gorgeous sceneries with Vietnamese,in particular,the photo exhibition of accomplishments celebrating the 40th anniversary of the Reform and Opening-up,the autumn concert of ethnic music from Guangxi Zhuang Autonomous Region,and the exposition of cultural and creative products from Nanjing City.展开更多
Two hominid teeth recovered in Mohui cave are morphologically distinguished from Australopithecus in Af-rica, but close to Homo erectus in China. These teeth are therefore provisionally assigned to Homo erectus. The a...Two hominid teeth recovered in Mohui cave are morphologically distinguished from Australopithecus in Af-rica, but close to Homo erectus in China. These teeth are therefore provisionally assigned to Homo erectus. The associ-ated mammalian fauna include Gigantopithecus blacki, Nes-toritherium sp., Sus xiaozhu, Sus peii and Ailuropoda microta, which are typical early Pleistocene taxa in South China. The general characteristics of the Mohui faunal assemblage are similar to the Longgupo site, which is dated to 2 Ma, imply-ing a contemporaneity for the two sites. To date, compared with the discoveries in Africa, far fewer early Pleistocene hominid fossils have been recovered in Asia, and there are intensive controversies concerning their stratigraphic prove-nience and typological and temporal positions. The hominid fossils from Mohui cave, with their reliable biostratigraphic positions and distinct typological features, provide important evidence regarding the issue of early human origins and evo-lution.展开更多
文摘The activated carbon with high surface area was prepared by KOH activation.It was further modified by H2SO4 and HNO3 to introduce more surface functional groups.The pore structure of the activated carbons before and after modification was analyzed based on the nitrogen adsorption isotherms.The morphology of those activated carbons was characterized using scanning electronic microscopy （SEM）.The surface functional groups were determined by Fourier transform infrared spectroscopy （FTIR）.The quantity of those groups was measured by the Boehm titration method.Cr（VI） removal by the activated carbons from aqueous solution was investigated at different pH values.The results show that compared with H2SO4,HNO3 destructs the original pore of the activated carbon more seriously and induces more acidic surface functional groups on the activated carbon.The pH value of the solution plays a key role in the Cr（VI） removal.The ability of reducing Cr（VI） to Cr（III） by the activated carbons is relative to the acidic surface functional groups.At higher pH values,the Cr（VI） removal ratio is improved by increasing the acidic surface functional groups of the activated carbons.At lower pH values,however,the acidic surface functional groups almost have no effect on the Cr（VI） removal by the activated carbon from aqueous solution.
基金Funded by the National Natural Science Foundation of China(No.51202249)the Key Projects in the National Science&Technology Pillar Program in the Twelfth Five-year Plan Period(No.2012BAB08B04)
文摘The low-melting phosphate glass was prepared for production of glass binders for protective coating of steel slab. Effects of different O/P ratios on glass structures and properties were analyzed. Differential thermal analysis （DTA） and infrared spectroscopy （IR） techniques were applied for low-melting glass binder. It was found that the glass transition temperature（T） was about 300 ℃ and softening temperature（T1） was about 480 ℃. The choice of O/P ratio was very important to the glass transition and softening temperatures. When more P=O bonds existed in the glass networks, P-O-P bond angle was deformed with decreasing of the ratio of O/E The coatings could adhere to the substrates instantaneously at 800 ℃ when the content of binder exceeded 3wt%. The optimal content of glass binder was 5wt%.
基金supported by China Postdoctoral Science Foundation(No.118918)West Light Foundation of the Chinese Academy of Science
文摘1 Introduction In the present paper,MgCl2·6H2O,FeCl3·6H2O,and CeCl3·6H2O were used as raw materials in the precipitationhydrothermal method to synthesize MgF eC e hydrotalcite.The effects of the Fe:Ce molar ratio on the composition,crystal structure,and thermal stability of hydrotalcite are examined.Energy-dispersive X-ray spectroscopy(EDS),X-
文摘China Cultural Center(CCC)in Hanoi,since its inauguration in 2017,has organized a great variety of performances and exhibitions to share China’s brilliant culture and gorgeous sceneries with Vietnamese,in particular,the photo exhibition of accomplishments celebrating the 40th anniversary of the Reform and Opening-up,the autumn concert of ethnic music from Guangxi Zhuang Autonomous Region,and the exposition of cultural and creative products from Nanjing City.
基金This work is supported by the National Natural Science Foundation of China(Grant No.40163001)the Emergency Excavation Fund from the National Culture Relics Bureau of China+1 种基金special funds of“Talents Project in the New Century”of the Guangxi Government(Grant No.2001216)the National Science Foundation,USA.
文摘Two hominid teeth recovered in Mohui cave are morphologically distinguished from Australopithecus in Af-rica, but close to Homo erectus in China. These teeth are therefore provisionally assigned to Homo erectus. The associ-ated mammalian fauna include Gigantopithecus blacki, Nes-toritherium sp., Sus xiaozhu, Sus peii and Ailuropoda microta, which are typical early Pleistocene taxa in South China. The general characteristics of the Mohui faunal assemblage are similar to the Longgupo site, which is dated to 2 Ma, imply-ing a contemporaneity for the two sites. To date, compared with the discoveries in Africa, far fewer early Pleistocene hominid fossils have been recovered in Asia, and there are intensive controversies concerning their stratigraphic prove-nience and typological and temporal positions. The hominid fossils from Mohui cave, with their reliable biostratigraphic positions and distinct typological features, provide important evidence regarding the issue of early human origins and evo-lution.
