The hydrogen adsorption (storage) studies upon Ni/A1203 nano-composite prepared by metal organic chemical vapor deposition technique (MOCVD) exploiting single source molec ular precursor (SSP) approach were carr...The hydrogen adsorption (storage) studies upon Ni/A1203 nano-composite prepared by metal organic chemical vapor deposition technique (MOCVD) exploiting single source molec ular precursor (SSP) approach were carried out. The Ni/A1203 nano-composite is prepared in cold walled MOCVD reactor by the decomposition of SSP, [H2AI(OtBu)]2, on a substrate holding Ni(acac)2 powder. The SSP is a reducing agent which reduces Ni+2 to Ni0 and works as source for Al203 matrix in which the Ni0 is dispersed. The resulting Ni/A1203 nano-composite is characterized by XRD, SEM, TEM, and EDX. The hydrogen adsorption (storage) studies are performed using home-made Sievert's type apparatus. The hydrogen storage studies reveal that approximately 2.9% (mass ratio) hydrogen can be stored in the Ni/A1203 nano-composite. The results show that Ni/A1203 nano-composite can be a po- tential candidate for hydrogen storage which can be used for onboard fuel purposes.展开更多
The public technique terrace is the research organization for providing the middle experimentation and applying research for technology conversion. Firstly, the paper analyzes the important function of the public tech...The public technique terrace is the research organization for providing the middle experimentation and applying research for technology conversion. Firstly, the paper analyzes the important function of the public technique terrace. Secondly, some suggestions on how to build up the public technique terrace are put forward from five aspects including government, enterprise, media organization, and so on.展开更多
Repetitive transcranial magnetic stimulation (rTMS) has been utilized as a therapeutic tool for neurodegenerative disorders including Alzheimer's disease. However, the precise mechanisms of its clinical effects rem...Repetitive transcranial magnetic stimulation (rTMS) has been utilized as a therapeutic tool for neurodegenerative disorders including Alzheimer's disease. However, the precise mechanisms of its clinical effects remain unknown. β-amyloid (Aβ) exhibits direct neurotoxic effects and is closely related to neuronal degeneration in Alzheimer's disease. Therefore, it has been hypothesized that the neuroprotective effects of rTMS are related to the mechanisms of protection against Aβ neurotoxicity. Organotypic hippocampal slices were prepared from 8-day old, Sprague Dawley rats. The tissue slices were exposed to 100 μmol/L Al3142 since day 12 in vitro with and without high-frequency (20 Hz) magnetic stimulation. Magnetic stimulation efficacy was evaluated by measuring neuronal nuclei (NeuN) protein expression and by observing cultures following propidium iodide fluorescence staining and bromodeoxyuridine (BrdU) immunohistochemistry. Lactate dehydrogenase activity was detected in the culture media to evaluate hippocampal neuronal damage. Our results demonstrated that high-frequency magnetic stimulation significantly reversed the reduction of NeuN protein expression because of Aβ1-42 exposure (P 〈 0.05) and significantly reduced the number of damaged cells in the hippocampal slices (P 〈 0.05). However, lactate dehydrogenase levels and anti-BrdU staining results did not reveal any statistical differences These findings indicate that high-frequency magnetic stimulation might have protective effect on hippocampal neurons from Aβ1-42 neurotoxicity.展开更多
A factor separation technique and an improved regional air quality model (RAQM) were applied to calculate synergistic contributions of anthropogenic volatile organic compounds (AVOCs),biogenic volatile organic com...A factor separation technique and an improved regional air quality model (RAQM) were applied to calculate synergistic contributions of anthropogenic volatile organic compounds (AVOCs),biogenic volatile organic compounds (BVOCs) and nitrogen oxides (NOx) to daily maximum surface O3(O3DM) concentrations in East Asia in summer (June to August 2000).The summer averaged synergistic impacts of AVOCs and NOx are dominant in most areas of North China,with a maximum of 60 ppbv,while those of BVOCs and NOx are notable only in some limited areas with high BVOC emissions in South China,with a maximum of 25 ppbv.This result implies that BVOCs contribute much less to summer averaged O3DM concentrations than AVOCs in most areas of East Asia at a coarse spatial resolution (1×1) although global emissions of BVOCs are much greater than those of AVOCs.Daily maximum total contributions of BVOCs can approach 20 ppbv in North China,but they can reach 40 ppbv in South China,approaching or exceeding those in some developed countries in Europe and North America.BVOC emissions in such special areas should be considered when O3 control measures are taken.Synergistic contributions among AVOCs,BVOCs and NOx significantly enhance O3 concentrations in the Beijing-Tianjin-Tangshan region and decrease them in some areas in South China.Thus,the total contributions of BVOCs to O3DM vary significantly from day to day and from location to location.This result suggests that O3 control measures obtained from episodic studies could be limited for long-term applications.展开更多
文摘The hydrogen adsorption (storage) studies upon Ni/A1203 nano-composite prepared by metal organic chemical vapor deposition technique (MOCVD) exploiting single source molec ular precursor (SSP) approach were carried out. The Ni/A1203 nano-composite is prepared in cold walled MOCVD reactor by the decomposition of SSP, [H2AI(OtBu)]2, on a substrate holding Ni(acac)2 powder. The SSP is a reducing agent which reduces Ni+2 to Ni0 and works as source for Al203 matrix in which the Ni0 is dispersed. The resulting Ni/A1203 nano-composite is characterized by XRD, SEM, TEM, and EDX. The hydrogen adsorption (storage) studies are performed using home-made Sievert's type apparatus. The hydrogen storage studies reveal that approximately 2.9% (mass ratio) hydrogen can be stored in the Ni/A1203 nano-composite. The results show that Ni/A1203 nano-composite can be a po- tential candidate for hydrogen storage which can be used for onboard fuel purposes.
文摘The public technique terrace is the research organization for providing the middle experimentation and applying research for technology conversion. Firstly, the paper analyzes the important function of the public technique terrace. Secondly, some suggestions on how to build up the public technique terrace are put forward from five aspects including government, enterprise, media organization, and so on.
文摘Repetitive transcranial magnetic stimulation (rTMS) has been utilized as a therapeutic tool for neurodegenerative disorders including Alzheimer's disease. However, the precise mechanisms of its clinical effects remain unknown. β-amyloid (Aβ) exhibits direct neurotoxic effects and is closely related to neuronal degeneration in Alzheimer's disease. Therefore, it has been hypothesized that the neuroprotective effects of rTMS are related to the mechanisms of protection against Aβ neurotoxicity. Organotypic hippocampal slices were prepared from 8-day old, Sprague Dawley rats. The tissue slices were exposed to 100 μmol/L Al3142 since day 12 in vitro with and without high-frequency (20 Hz) magnetic stimulation. Magnetic stimulation efficacy was evaluated by measuring neuronal nuclei (NeuN) protein expression and by observing cultures following propidium iodide fluorescence staining and bromodeoxyuridine (BrdU) immunohistochemistry. Lactate dehydrogenase activity was detected in the culture media to evaluate hippocampal neuronal damage. Our results demonstrated that high-frequency magnetic stimulation significantly reversed the reduction of NeuN protein expression because of Aβ1-42 exposure (P 〈 0.05) and significantly reduced the number of damaged cells in the hippocampal slices (P 〈 0.05). However, lactate dehydrogenase levels and anti-BrdU staining results did not reveal any statistical differences These findings indicate that high-frequency magnetic stimulation might have protective effect on hippocampal neurons from Aβ1-42 neurotoxicity.
基金supported by the National Natural Science Foundation of China(No.40905055,41175105)the Key Project of the Chinese Academy of Sciences(No.KZCX1-YW-06-04)
文摘A factor separation technique and an improved regional air quality model (RAQM) were applied to calculate synergistic contributions of anthropogenic volatile organic compounds (AVOCs),biogenic volatile organic compounds (BVOCs) and nitrogen oxides (NOx) to daily maximum surface O3(O3DM) concentrations in East Asia in summer (June to August 2000).The summer averaged synergistic impacts of AVOCs and NOx are dominant in most areas of North China,with a maximum of 60 ppbv,while those of BVOCs and NOx are notable only in some limited areas with high BVOC emissions in South China,with a maximum of 25 ppbv.This result implies that BVOCs contribute much less to summer averaged O3DM concentrations than AVOCs in most areas of East Asia at a coarse spatial resolution (1×1) although global emissions of BVOCs are much greater than those of AVOCs.Daily maximum total contributions of BVOCs can approach 20 ppbv in North China,but they can reach 40 ppbv in South China,approaching or exceeding those in some developed countries in Europe and North America.BVOC emissions in such special areas should be considered when O3 control measures are taken.Synergistic contributions among AVOCs,BVOCs and NOx significantly enhance O3 concentrations in the Beijing-Tianjin-Tangshan region and decrease them in some areas in South China.Thus,the total contributions of BVOCs to O3DM vary significantly from day to day and from location to location.This result suggests that O3 control measures obtained from episodic studies could be limited for long-term applications.