The carbon cycle of forest ecosystems plays a key role in regulating CO2 concentrations in the atmosphere. Research on carbon storage estimation of forest ecosystems has become a major research topic. However, carbon ...The carbon cycle of forest ecosystems plays a key role in regulating CO2 concentrations in the atmosphere. Research on carbon storage estimation of forest ecosystems has become a major research topic. However, carbon budgets of subtropical forest ecosystems have received little attention. Reports of soil carbon storage and topographic heterogeneity of carbon storage are limited. This study focused on the Jinggang Mountain National Nature Reserve as an example of a mid-subtropical forest and evaluated soil and vegetation carbon storage by field sampling combined with GIS, RS and GPS technology. We classified the forest into nine forest types using ALOS high-resolution remote sensing images. The evergreen broad-leaved forest has the largest area, occupying 26.5% of the total area, followed by coniferous and broad-leaved mixed forests and warm temperate coniferous forest, occupying 24.2 and 22.9%, respectively. The vegetation and soil carbon storage of the whole forest ecosystem were 1,692,344 and 5,514,707 t, with a carbon density of 7.4 and 24.2 kg/m^2, respectively, which suggests that the ecosystem has great carbon storage capacity. The topographic heterogeneity of the carbon storage was also analysed. The largest vegetation storage and soil storage is at 700–800 and 1000–1100 m, respectively. The vegetation carbon storage is highest in the southeast, south and southwest.展开更多
Connexin 43,a gap junction protein,is expressed mainly in glia in the central nervous system.Neuroinflammation plays an important role in central nervous system injury.Changes to glial connexin 43 levels and neuroinfl...Connexin 43,a gap junction protein,is expressed mainly in glia in the central nervous system.Neuroinflammation plays an important role in central nervous system injury.Changes to glial connexin 43 levels and neuroinflammation may trigger brain injury and neurodegenerative diseases.To illustrate the relationship between connexin 43 and neuroinflammation,this study investigated how connexin 43 expression levels change in lipopolysaccharide-stimulated rat C6 glioma cells.C6 cells were treated with 0.05,0.25,0.5,1,2.5 and 5 μg/mL lipopolysaccharide for 24 hours.The nitrite estimation-detected nitric oxide release level was elevated substantially after lipopolysaccharide stimulation.To test the transcriptional level changes of inducible nitric oxide synthase,tumor necrosis factor-α and connexin 43 mRNA,C6 cells were treated with 5 μg/mL lipopolysaccharide for 3-48 hours.Reverse transcription-PCR showed that the expression of inducible nitric oxide synthase and tumor necrosis factor-α mRNA increased over time,but connexin 43 mRNA levels increased in lipopolysaccharide-stimulated C6 cells at 3 and 6 hours,and then decreased from 12 to 48 hours.Connexin 43 protein expression was detected by immunofluorescence staining,and the protein levels matched the mRNA expression levels.These results suggest that connexin 43 expression is biphasic in lipopolysaccharide-induced neuroinflammation in C6 cells,which may be correlated with the connexin 43 compensatory mechanism.展开更多
[Objective]Protective antigen gene MPT-64 was cloned from genomic DNA of Mycobacterium tuberculosis and transferred into prokaryotic competent cells for expression to obtain MPT-64 fusion protein.[Method]Based on the ...[Objective]Protective antigen gene MPT-64 was cloned from genomic DNA of Mycobacterium tuberculosis and transferred into prokaryotic competent cells for expression to obtain MPT-64 fusion protein.[Method]Based on the GenBank,primers were designed for amplification of MPT-64 gene,and the recombinant plasmid pET-32a-MPT-64 was constructed.The recombinant plasmid was expressed in prokaryotic expression vector to obtain fusion protein.[Result]Protective antigen gene MPT-64 was successfully cloned.The recombinant plasmid pET-32a-MPT-64 was obtained.MPT-64 fusion protein was successfully expressed.[Conclusion]This study laid solid foundation for the prevention,diagnosis,treatment of tuberculosis and the development of tuberculosis vaccines.展开更多
Particle size reduction of Y_(3)Al_(5)O_(12):Ce(YAG:Ce) phosphor is highly needed for micro-LED display applications.In this work,size control of YAG:Ce phosphor particles is achieved via carbon coating and further he...Particle size reduction of Y_(3)Al_(5)O_(12):Ce(YAG:Ce) phosphor is highly needed for micro-LED display applications.In this work,size control of YAG:Ce phosphor particles is achieved via carbon coating and further heat treatment.A thin layer of carbon is deposited on the surface of YAG:Ce by chemical vapor deposition.During the heat treatment,carbon reacts with oxygen element in the phosphor and escapes from phosphor particles.The reaction results in the phosphor breaking into smaller particles.The phosphors were characterized by laser light scattering for particle size distribution,scanning electron microscopy(SEM),transmission electron microscopy for morphologies,X-ray diffraction refinements for crystal structure and electron energy-loss spectroscopy for elemental analysis.It is demonstrated that the median diameter(D_(50)) of the phosphor particle size is significantly reduced from 19.1 to 0.96 μm yet the photoluminescent properties have little changes.The carbon coating and further heat treatment method show potential application in size control of phosphors.展开更多
In this paper,hp-adaptive finite element methods are studied for timeharmonic Maxwell’s equations.We propose the parallel hp-adaptive algorithms on conforming unstructured tetrahedral meshes based on residual-based a...In this paper,hp-adaptive finite element methods are studied for timeharmonic Maxwell’s equations.We propose the parallel hp-adaptive algorithms on conforming unstructured tetrahedral meshes based on residual-based a posteriori error estimates.Extensive numerical experiments are reported to investigate the efficiency of the hp-adaptive methods for point singularities,edge singularities,and an engineering benchmark problem of Maxwell’s equations.The hp-adaptive methods show much better performance than the h-adaptive method.展开更多
基金supported by the National Natural Science Foundation of China(41701209,41501095,41601198)
文摘The carbon cycle of forest ecosystems plays a key role in regulating CO2 concentrations in the atmosphere. Research on carbon storage estimation of forest ecosystems has become a major research topic. However, carbon budgets of subtropical forest ecosystems have received little attention. Reports of soil carbon storage and topographic heterogeneity of carbon storage are limited. This study focused on the Jinggang Mountain National Nature Reserve as an example of a mid-subtropical forest and evaluated soil and vegetation carbon storage by field sampling combined with GIS, RS and GPS technology. We classified the forest into nine forest types using ALOS high-resolution remote sensing images. The evergreen broad-leaved forest has the largest area, occupying 26.5% of the total area, followed by coniferous and broad-leaved mixed forests and warm temperate coniferous forest, occupying 24.2 and 22.9%, respectively. The vegetation and soil carbon storage of the whole forest ecosystem were 1,692,344 and 5,514,707 t, with a carbon density of 7.4 and 24.2 kg/m^2, respectively, which suggests that the ecosystem has great carbon storage capacity. The topographic heterogeneity of the carbon storage was also analysed. The largest vegetation storage and soil storage is at 700–800 and 1000–1100 m, respectively. The vegetation carbon storage is highest in the southeast, south and southwest.
基金sponsored by the National Natural Science Foundation of China,No. 30901323
文摘Connexin 43,a gap junction protein,is expressed mainly in glia in the central nervous system.Neuroinflammation plays an important role in central nervous system injury.Changes to glial connexin 43 levels and neuroinflammation may trigger brain injury and neurodegenerative diseases.To illustrate the relationship between connexin 43 and neuroinflammation,this study investigated how connexin 43 expression levels change in lipopolysaccharide-stimulated rat C6 glioma cells.C6 cells were treated with 0.05,0.25,0.5,1,2.5 and 5 μg/mL lipopolysaccharide for 24 hours.The nitrite estimation-detected nitric oxide release level was elevated substantially after lipopolysaccharide stimulation.To test the transcriptional level changes of inducible nitric oxide synthase,tumor necrosis factor-α and connexin 43 mRNA,C6 cells were treated with 5 μg/mL lipopolysaccharide for 3-48 hours.Reverse transcription-PCR showed that the expression of inducible nitric oxide synthase and tumor necrosis factor-α mRNA increased over time,but connexin 43 mRNA levels increased in lipopolysaccharide-stimulated C6 cells at 3 and 6 hours,and then decreased from 12 to 48 hours.Connexin 43 protein expression was detected by immunofluorescence staining,and the protein levels matched the mRNA expression levels.These results suggest that connexin 43 expression is biphasic in lipopolysaccharide-induced neuroinflammation in C6 cells,which may be correlated with the connexin 43 compensatory mechanism.
基金Supported by Project of Science and Technology Development of Jilin Province(20140204018YY)
文摘[Objective]Protective antigen gene MPT-64 was cloned from genomic DNA of Mycobacterium tuberculosis and transferred into prokaryotic competent cells for expression to obtain MPT-64 fusion protein.[Method]Based on the GenBank,primers were designed for amplification of MPT-64 gene,and the recombinant plasmid pET-32a-MPT-64 was constructed.The recombinant plasmid was expressed in prokaryotic expression vector to obtain fusion protein.[Result]Protective antigen gene MPT-64 was successfully cloned.The recombinant plasmid pET-32a-MPT-64 was obtained.MPT-64 fusion protein was successfully expressed.[Conclusion]This study laid solid foundation for the prevention,diagnosis,treatment of tuberculosis and the development of tuberculosis vaccines.
基金the financial support from the National Natural Science Foundation of China (51602040 and 51872039)the Science and Technology Program of Sichuan (M112018JY0025)the Scientific Research Foundation for New Teachers of UESTC (A03013023601007)
基金supported by the National Natural Science Foundation of China(51602040,51872039,51525202 and 51902098)the Science and Technology Program of Sichuan(M112018JY0025)+1 种基金Scientific Research Foundation for New Teachers of UESTC(A03013023601007)the Ministry of Science and Technology of China(MOST,2016YFA0300802)。
基金the National Natural Science Foundation of China(51772042,51802294 and 51972046)Sichuan Science and Technology Plan(2017JY0348,2018FZ0100)"111"Center(B13042)。
文摘Particle size reduction of Y_(3)Al_(5)O_(12):Ce(YAG:Ce) phosphor is highly needed for micro-LED display applications.In this work,size control of YAG:Ce phosphor particles is achieved via carbon coating and further heat treatment.A thin layer of carbon is deposited on the surface of YAG:Ce by chemical vapor deposition.During the heat treatment,carbon reacts with oxygen element in the phosphor and escapes from phosphor particles.The reaction results in the phosphor breaking into smaller particles.The phosphors were characterized by laser light scattering for particle size distribution,scanning electron microscopy(SEM),transmission electron microscopy for morphologies,X-ray diffraction refinements for crystal structure and electron energy-loss spectroscopy for elemental analysis.It is demonstrated that the median diameter(D_(50)) of the phosphor particle size is significantly reduced from 19.1 to 0.96 μm yet the photoluminescent properties have little changes.The carbon coating and further heat treatment method show potential application in size control of phosphors.
基金supported in part by the National Basic Research Project under the grant 2011CB309703,by the Funds for Creative Research Groups of China(Grant No.11021101)by China NSF under the grant 60873177+2 种基金supported in part by China NSF under the grants 11031006 and 11171334by the Funds for Creative Research Groups of China(Grant No.11021101)by the National Magnetic Confinement Fusion Science Program(Grant No.2011GB105003).
文摘In this paper,hp-adaptive finite element methods are studied for timeharmonic Maxwell’s equations.We propose the parallel hp-adaptive algorithms on conforming unstructured tetrahedral meshes based on residual-based a posteriori error estimates.Extensive numerical experiments are reported to investigate the efficiency of the hp-adaptive methods for point singularities,edge singularities,and an engineering benchmark problem of Maxwell’s equations.The hp-adaptive methods show much better performance than the h-adaptive method.
