A novel anaerobic reactor, jet biogas inter-loop anaerobic fluidized bed (JBILAFB), was designed and constructed. The start-up and performance of the reactor was investigated in the Process. of .artificial glucose w...A novel anaerobic reactor, jet biogas inter-loop anaerobic fluidized bed (JBILAFB), was designed and constructed. The start-up and performance of the reactor was investigated in the Process. of .artificial glucose wastewater treatment. With the wastewater recycle ratio of 2.5 : 1, the recycled wastewater with biogas could mix sludge and wastewater in the JBILAFB reactor completely. The start-up of the JBILAFB reactor could be completed in less than 70 d through maintenance of hydraulic retention time (HR^I") and stepwise increase of feed total organic carbon (TOC) concentration. After the start-up, with the volumetric TOC loadings of 14.3 kg·m ^-3·d^-1, the TOC removal ratio, the effluent pH, and the volatile fatty acids (VFA)/alkalinity of the JBILAFB reactor were more than 80%, close to 7.0 and less than 0.4, respectively. Moreover, CH4 was produced at more than 70% of the theoretical value, The reactor exhibited high stability under the condition of high volumetric TOC loading. Sludge granules in the JBILAFB reactor were developed during the start-up and their sizes were enlarged with the stepwise increase of volumetric TOC loadings from 0.8 kg.m^-3.d ^-1 to 14.3 kg.m^-3.d^-1. Granules, an offwhite color and a similar spherical shape, were mainly comprised of global-like bacteria. These had good methanogenic activity and settleability, which were formed probably through adhesion of the bacteria. Some inorganic metal compounds such as Fe, Ca, Mg, Al, etc. were advantageous to the formation of the granules.展开更多
The grain size and palinology of sediment and the frequency of ^14C dada provide an integrated reconstruction of the Holocene warm-humid phases of the North China Plain. Two clear intense and long-lasting warm-humid p...The grain size and palinology of sediment and the frequency of ^14C dada provide an integrated reconstruction of the Holocene warm-humid phases of the North China Plain. Two clear intense and long-lasting warm-humid phases were identified by comprehensive research in this region. The first phase was dated back to the early Holocene (9 000-7 000 a BP), and the second was centered at 5 000-3 000 a BP. The warm-humid episode between 9 000 and 7 000 a BP was also recognized at other sites showing global climatic trends rather than local events. Compared with the concern to the warm-humid phase of the early Holocene, the second one was not paid enough attention in the last few decades. The compilation of the Holocene paleoclimate data suggests that perhaps the second warm-humid phase was pervasive in monsoon region of China. In perspective of environmental archaeology, much attention should be devoted to it, because the flourish and adaptation of the Neolithic cultures and the building up of the first state seem to corresponding to the general warm-humid climatic conditions of this period. In addition, a warm-humid interval at 7 20045 500 a BP was recognized by the grain size data from three sites. However, this warm-humid event was not shown in pollen assemblage and temporal distribution of ^14C data. Perhaps, the resolution for climatic reconstruction from pollen and temporal distribution of ^14C data cited here is relatively low and small-amplitude and short-period climatic events cannot be well reflected by the data. Due to the difference in locality and elevation of sampling site, as well as in resolution of proxy records, it is difficult to make precise correlation. Further work is needed in the future.展开更多
In the past few years China has consistently and increasingly encouraged innovation,making great headway in such sectors as heavy equipment manufacturing,high-speed rail,biopharmaceuticals,new energy and robotics.Inno...In the past few years China has consistently and increasingly encouraged innovation,making great headway in such sectors as heavy equipment manufacturing,high-speed rail,biopharmaceuticals,new energy and robotics.Innovation has become an important engine boosting economic and social development in China.展开更多
Animal intestine is a favorable habitat to microbes. It facilitates the evolution of dense and diversified microbial communities that are highly active and persistent throughout life span. Here, we stimulate this uniq...Animal intestine is a favorable habitat to microbes. It facilitates the evolution of dense and diversified microbial communities that are highly active and persistent throughout life span. Here, we stimulate this unique biosystem to develop high-efficient continuous bio-manufacturing processes. The pig small intestine was explored as a novel bioreactor with industrial Saccharornyces cerevisiae for biofuel production. Results showed that the small intestine was a beneficial material for cell adherence. The cells on the intestine exhibited the abilities of self- immobilization, self-duplication and self-repairing. Therefore the intestine-based S. cerevisiae could be continu- ously used for a long time at high metabolic activities. Both the fermentation speed and ethanol yield were im- proved. This study provides valuable insights into the functions of intestine-based biosystem and should inspire the development of bionic industrial processes. Future dissection of the interface mechanism and design of more bionic materials will make bioprocesses more economically favorable and environmentally sustainable.展开更多
Oxide heterointerface is a platform to create unprecedented two-dimensional electron gas, superconductivity and ferromagnetism, arising from a polar discontinuity at the interface. In particular, the ability to tune t...Oxide heterointerface is a platform to create unprecedented two-dimensional electron gas, superconductivity and ferromagnetism, arising from a polar discontinuity at the interface. In particular, the ability to tune these intriguing effects paves a way to elucidate their fundamental physics and to develop novel electronic/magnetic devices. In this work, we report for the first time that a ferroelectric polarization screening at SrTiO_(3)/PbTiO_(3) interface is able to drive an electronic construction of Ti atom, giving rise to room-temperature ferromagnetism. Surprisingly, such ferromagnetism can be switched to antiferromagnetism by applying a magnetic field, which is reversible. A coupling of itinerant electrons with local moments at interfacial Ti3d orbital was proposed to explain the magnetism. The localization of the itinerant electrons under a magnetic field is responsible for the suppression of magnetism. These findings provide new insights into interfacial magnetism and their control by magnetic field relevant interfacial electrons promising for device applications.展开更多
According to archaeological investigation and preliminary excavation, the Yangjia Site, located in the northern Taihu Lake region, at Wuxi City, Jiangsu Province, is a Neolithic archaeological site dominated by cultur...According to archaeological investigation and preliminary excavation, the Yangjia Site, located in the northern Taihu Lake region, at Wuxi City, Jiangsu Province, is a Neolithic archaeological site dominated by cultural remains attributed to the late Majiabang Culture(6270–5920 cal. a BP). Here a systematic archaeobotanical study was conducted to investigate vegetation landscape, environmental characteristics and rice agriculture in the prehistoric northern Taihu Lake area. The abundance, frequency and standard density of charred rice were the highest of all of the remains of the seed plants unearthed. In addition, a variety of wetland weeds, such as Haloragaceae, Cyperaceae, Carex sp., and Oxalis corniculata, were found. Pollen and phytoliths recorded that the evergreen-deciduous broadleaf mixed forest(represented by Quercus and Castanopsis) tends to decrease, while Poaceae was the most significant of the terrestrial herbs, water area expanded and water activities strengthened, indicating generally warm and humid conditions at the Yangjia Site during the late Majiabang Culture. All indicators of pollen, phytolith and macro-plant remains suggest that wild rice should be once distributed at or around the site before human occupation, after which rice agriculture progressed rapidly during the late Majiabang Culture.展开更多
基金Supported by the National Natural Science Foundation of China (No.50278036), the Natural Science Foundation of Guangdong Province (No.04105951) and the National High Technology Research and Development Program of China (No.2006AA06Z378).
文摘A novel anaerobic reactor, jet biogas inter-loop anaerobic fluidized bed (JBILAFB), was designed and constructed. The start-up and performance of the reactor was investigated in the Process. of .artificial glucose wastewater treatment. With the wastewater recycle ratio of 2.5 : 1, the recycled wastewater with biogas could mix sludge and wastewater in the JBILAFB reactor completely. The start-up of the JBILAFB reactor could be completed in less than 70 d through maintenance of hydraulic retention time (HR^I") and stepwise increase of feed total organic carbon (TOC) concentration. After the start-up, with the volumetric TOC loadings of 14.3 kg·m ^-3·d^-1, the TOC removal ratio, the effluent pH, and the volatile fatty acids (VFA)/alkalinity of the JBILAFB reactor were more than 80%, close to 7.0 and less than 0.4, respectively. Moreover, CH4 was produced at more than 70% of the theoretical value, The reactor exhibited high stability under the condition of high volumetric TOC loading. Sludge granules in the JBILAFB reactor were developed during the start-up and their sizes were enlarged with the stepwise increase of volumetric TOC loadings from 0.8 kg.m^-3.d ^-1 to 14.3 kg.m^-3.d^-1. Granules, an offwhite color and a similar spherical shape, were mainly comprised of global-like bacteria. These had good methanogenic activity and settleability, which were formed probably through adhesion of the bacteria. Some inorganic metal compounds such as Fe, Ca, Mg, Al, etc. were advantageous to the formation of the granules.
基金Supported by the Humanity and Social Sciences Research of Ministry of Education, China (No. 06JC780001)the Major Program of the National Natural Science Foundation of China (No. 40599420)
文摘The grain size and palinology of sediment and the frequency of ^14C dada provide an integrated reconstruction of the Holocene warm-humid phases of the North China Plain. Two clear intense and long-lasting warm-humid phases were identified by comprehensive research in this region. The first phase was dated back to the early Holocene (9 000-7 000 a BP), and the second was centered at 5 000-3 000 a BP. The warm-humid episode between 9 000 and 7 000 a BP was also recognized at other sites showing global climatic trends rather than local events. Compared with the concern to the warm-humid phase of the early Holocene, the second one was not paid enough attention in the last few decades. The compilation of the Holocene paleoclimate data suggests that perhaps the second warm-humid phase was pervasive in monsoon region of China. In perspective of environmental archaeology, much attention should be devoted to it, because the flourish and adaptation of the Neolithic cultures and the building up of the first state seem to corresponding to the general warm-humid climatic conditions of this period. In addition, a warm-humid interval at 7 20045 500 a BP was recognized by the grain size data from three sites. However, this warm-humid event was not shown in pollen assemblage and temporal distribution of ^14C data. Perhaps, the resolution for climatic reconstruction from pollen and temporal distribution of ^14C data cited here is relatively low and small-amplitude and short-period climatic events cannot be well reflected by the data. Due to the difference in locality and elevation of sampling site, as well as in resolution of proxy records, it is difficult to make precise correlation. Further work is needed in the future.
文摘In the past few years China has consistently and increasingly encouraged innovation,making great headway in such sectors as heavy equipment manufacturing,high-speed rail,biopharmaceuticals,new energy and robotics.Innovation has become an important engine boosting economic and social development in China.
文摘Animal intestine is a favorable habitat to microbes. It facilitates the evolution of dense and diversified microbial communities that are highly active and persistent throughout life span. Here, we stimulate this unique biosystem to develop high-efficient continuous bio-manufacturing processes. The pig small intestine was explored as a novel bioreactor with industrial Saccharornyces cerevisiae for biofuel production. Results showed that the small intestine was a beneficial material for cell adherence. The cells on the intestine exhibited the abilities of self- immobilization, self-duplication and self-repairing. Therefore the intestine-based S. cerevisiae could be continu- ously used for a long time at high metabolic activities. Both the fermentation speed and ethanol yield were im- proved. This study provides valuable insights into the functions of intestine-based biosystem and should inspire the development of bionic industrial processes. Future dissection of the interface mechanism and design of more bionic materials will make bioprocesses more economically favorable and environmentally sustainable.
基金supported by the National Natural Science Foundation of China (U1909212, U1809217, and 11474249)supported by the U.S. Department of Energy, Office of Basic Energy Science, Division of Materials Sciences and Engineering (Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358)。
文摘Oxide heterointerface is a platform to create unprecedented two-dimensional electron gas, superconductivity and ferromagnetism, arising from a polar discontinuity at the interface. In particular, the ability to tune these intriguing effects paves a way to elucidate their fundamental physics and to develop novel electronic/magnetic devices. In this work, we report for the first time that a ferroelectric polarization screening at SrTiO_(3)/PbTiO_(3) interface is able to drive an electronic construction of Ti atom, giving rise to room-temperature ferromagnetism. Surprisingly, such ferromagnetism can be switched to antiferromagnetism by applying a magnetic field, which is reversible. A coupling of itinerant electrons with local moments at interfacial Ti3d orbital was proposed to explain the magnetism. The localization of the itinerant electrons under a magnetic field is responsible for the suppression of magnetism. These findings provide new insights into interfacial magnetism and their control by magnetic field relevant interfacial electrons promising for device applications.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDA05130501)the National Natural Science Foundation of China (Grant Nos. 41471167, 41102114)
文摘According to archaeological investigation and preliminary excavation, the Yangjia Site, located in the northern Taihu Lake region, at Wuxi City, Jiangsu Province, is a Neolithic archaeological site dominated by cultural remains attributed to the late Majiabang Culture(6270–5920 cal. a BP). Here a systematic archaeobotanical study was conducted to investigate vegetation landscape, environmental characteristics and rice agriculture in the prehistoric northern Taihu Lake area. The abundance, frequency and standard density of charred rice were the highest of all of the remains of the seed plants unearthed. In addition, a variety of wetland weeds, such as Haloragaceae, Cyperaceae, Carex sp., and Oxalis corniculata, were found. Pollen and phytoliths recorded that the evergreen-deciduous broadleaf mixed forest(represented by Quercus and Castanopsis) tends to decrease, while Poaceae was the most significant of the terrestrial herbs, water area expanded and water activities strengthened, indicating generally warm and humid conditions at the Yangjia Site during the late Majiabang Culture. All indicators of pollen, phytolith and macro-plant remains suggest that wild rice should be once distributed at or around the site before human occupation, after which rice agriculture progressed rapidly during the late Majiabang Culture.