The nanocrystalline and amorphous Mg-Nd-Ni-Cu quaternary alloys with a composition of （Mg24Ni10Cu2）loo-xNdx （x = 0-20） were prepared by melt spinning. The X-ray diffraction and transmission electron microscopy ins...The nanocrystalline and amorphous Mg-Nd-Ni-Cu quaternary alloys with a composition of （Mg24Ni10Cu2）loo-xNdx （x = 0-20） were prepared by melt spinning. The X-ray diffraction and transmission electron microscopy inspections reveal that, by varying the spinning rate and the Nd content, different microstructures could be obtained by melt spinning. Particularly, the as-spun Nd-free alloy holds an entire nanocrystalline structure but the as-spun Nd-added alloy has a nanocrystalline and amorphous structure, which implies that the addition of Nd facilitates the glass forming in the Mg2Ni-type alloy. Also, the degree of the amorphization in the as-spun Nd-added alloys clearly increases with increasing the spinning rate and the Nd content. The H-storage capacity and the hydrogenation kinetics of amorphous, partially and completely nanocrystalline alloys were investigated and it was found that they are dependent on the microstructure and the phase composition of the alloys. Specially, enhancing the spinning rate from 0 （the as-cast was defined as the spinning rate of 0 m/s） to 40 m/s makes the hydrogen absorption saturation ratio （R5a） （a ratio of the hydrogen absorption quantity in 5 min to the saturated hydrogen absorption capacity） increase from 35.2% to 90.3% and the hydrogen desorption ratio （R10d） （a ratio of the hydrogen desorption quantity in 10 min to the saturated hydrogen absorption capacity） rise from 12.7% to 44.9% for the （x = 5） alloy. And the growing of the Nd content from 0 to 20 gives rise to the R5a and R10d values rising from 85.7% to 94.5% and from 36.7% to 54.8% for the as-spun （30 m/s） alloys, respectively.展开更多
The nanocrystalline and amorphous LaMg11Ni ＋ x wt% Ni （x = 100, 200） composites were synthesized by the mechanical milling, and their gaseous and electrochemical hydrogen storage kinetics performance were systemati...The nanocrystalline and amorphous LaMg11Ni ＋ x wt% Ni （x = 100, 200） composites were synthesized by the mechanical milling, and their gaseous and electrochemical hydrogen storage kinetics performance were systematically investigated, The results indicate that the as-milled composites exhibit excellent hydrogen storage kinetic performances, and increasing Ni content significantly facilitates the improvement of the hydrogen storage kinetics properties of the composites. The gaseous and electrochemical hydrogen storage kinetics of the composites reaches a maximum value with the variation of milling time. Increasing Ni content and milling time both make the hydrogen desorption activation energy lower, which are responsible for the enhancement in the hydrogen storage kinetics properties of the composites. The diffusion coefficient of hydrogen atom and activation enthalpy of charge transfer on the surface of the as-milled composites were also calculated, which are considered to be the dominated factors for the electrochemical high rate discharge ability.展开更多
A new hybrid method, Monte-Carlo-Heat-Flux （MCHF） method, was presented to analyze the radiative heat transfer of participating medium in a three-dimensional rectangular enclosure using combined the Monte-Carlo meth...A new hybrid method, Monte-Carlo-Heat-Flux （MCHF） method, was presented to analyze the radiative heat transfer of participating medium in a three-dimensional rectangular enclosure using combined the Monte-Carlo method with the heat flux method. Its accuracy and reliability was proved by comparing the computational results with exact results from classical ＂Zone Method＂.展开更多
Epoxy resin/Ni@C nanoparticle composites with aligned microstructure were prepared by using a procedure of magnetic field assisted curing. The results show that the resistivity of composites exhibits negative temperat...Epoxy resin/Ni@C nanoparticle composites with aligned microstructure were prepared by using a procedure of magnetic field assisted curing. The results show that the resistivity of composites exhibits negative temperature coefficient （NTC） effect above room temperature, and can be adjusted by varying the content filler and the magnitude of magnetic field applied. Hill＇s quantum tunneling model was modified to understand the electrical conduction mechanism in the composites. It shows that the NTC effect ascribes to the dominant thermal activated tunneling transport of electron across adjacent nanoparticles, as well as the low thermal expansivity of epoxy resin matrix.展开更多
Salmonella typhimurium is probably most extensively studied tumor-targeting bacteria and SL7207 is one of its attenuated strains.SL7207 was first made for bacterial vaccine development and its therapeutic efficacy and...Salmonella typhimurium is probably most extensively studied tumor-targeting bacteria and SL7207 is one of its attenuated strains.SL7207 was first made for bacterial vaccine development and its therapeutic efficacy and safety for hepatoellular carcinoma has not been characterized.In this study,the inhibitory ability of SL 7207-lux on human hepatoma HepG2 cells was tested in vitro and in vivo.A bacterial luminescent gene cluster(lux CDA BE)was transfected into SL7207 to better monitor the invasion of the bacteria.The results show that SL7207-lux can rapidly enter HepG2 cells and localize in the cytoplasm.This invasion represses ell proliferation and induces apoptosis.In vivo real-time invasion studies showed that the bacteria gradually accumulate in the tumor.This enrichment was confirmed by anatomic observation at 5 days after inoculation.About 40%of tumor growth was inhibited by SL7207-lxx at 34 days post-treatment without significant loss of body weight.The area of necrosis of tumor tissue was clearly increased in the treated group.Bacterial quantification showed that the number of colony-forming units per gram of bacteria within tumor tissue was approximately 1000-fold higher than that of liver and spleen.These data suggest that attenuated S.typhimurium strain SL7207 has potential for the treatment of cancers.展开更多
基金the financial support from the National Natural Science Foundation of China,China (Nos.51161015 and 51371094)the Natural Science Foundation of Inner Mongolia,China(No.2011ZD10)
文摘The nanocrystalline and amorphous Mg-Nd-Ni-Cu quaternary alloys with a composition of （Mg24Ni10Cu2）loo-xNdx （x = 0-20） were prepared by melt spinning. The X-ray diffraction and transmission electron microscopy inspections reveal that, by varying the spinning rate and the Nd content, different microstructures could be obtained by melt spinning. Particularly, the as-spun Nd-free alloy holds an entire nanocrystalline structure but the as-spun Nd-added alloy has a nanocrystalline and amorphous structure, which implies that the addition of Nd facilitates the glass forming in the Mg2Ni-type alloy. Also, the degree of the amorphization in the as-spun Nd-added alloys clearly increases with increasing the spinning rate and the Nd content. The H-storage capacity and the hydrogenation kinetics of amorphous, partially and completely nanocrystalline alloys were investigated and it was found that they are dependent on the microstructure and the phase composition of the alloys. Specially, enhancing the spinning rate from 0 （the as-cast was defined as the spinning rate of 0 m/s） to 40 m/s makes the hydrogen absorption saturation ratio （R5a） （a ratio of the hydrogen absorption quantity in 5 min to the saturated hydrogen absorption capacity） increase from 35.2% to 90.3% and the hydrogen desorption ratio （R10d） （a ratio of the hydrogen desorption quantity in 10 min to the saturated hydrogen absorption capacity） rise from 12.7% to 44.9% for the （x = 5） alloy. And the growing of the Nd content from 0 to 20 gives rise to the R5a and R10d values rising from 85.7% to 94.5% and from 36.7% to 54.8% for the as-spun （30 m/s） alloys, respectively.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 51161015 and 51371094)
文摘The nanocrystalline and amorphous LaMg11Ni ＋ x wt% Ni （x = 100, 200） composites were synthesized by the mechanical milling, and their gaseous and electrochemical hydrogen storage kinetics performance were systematically investigated, The results indicate that the as-milled composites exhibit excellent hydrogen storage kinetic performances, and increasing Ni content significantly facilitates the improvement of the hydrogen storage kinetics properties of the composites. The gaseous and electrochemical hydrogen storage kinetics of the composites reaches a maximum value with the variation of milling time. Increasing Ni content and milling time both make the hydrogen desorption activation energy lower, which are responsible for the enhancement in the hydrogen storage kinetics properties of the composites. The diffusion coefficient of hydrogen atom and activation enthalpy of charge transfer on the surface of the as-milled composites were also calculated, which are considered to be the dominated factors for the electrochemical high rate discharge ability.
基金financially supported by the National Natural Science Foundation of China (No.50464004)
文摘A new hybrid method, Monte-Carlo-Heat-Flux （MCHF） method, was presented to analyze the radiative heat transfer of participating medium in a three-dimensional rectangular enclosure using combined the Monte-Carlo method with the heat flux method. Its accuracy and reliability was proved by comparing the computational results with exact results from classical ＂Zone Method＂.
基金supported by the National Natural Sci-ence Foundation of China under grant No. 50704021.
文摘Epoxy resin/Ni@C nanoparticle composites with aligned microstructure were prepared by using a procedure of magnetic field assisted curing. The results show that the resistivity of composites exhibits negative temperature coefficient （NTC） effect above room temperature, and can be adjusted by varying the content filler and the magnitude of magnetic field applied. Hill＇s quantum tunneling model was modified to understand the electrical conduction mechanism in the composites. It shows that the NTC effect ascribes to the dominant thermal activated tunneling transport of electron across adjacent nanoparticles, as well as the low thermal expansivity of epoxy resin matrix.
基金This research was supported by grants from National Basic Research Program of China(No.2009CB521807)National Science Foundation of China(No.81101720)National S&T Major Special Project on Major New Drug Innovation(No.2010ZX09401-403).
文摘Salmonella typhimurium is probably most extensively studied tumor-targeting bacteria and SL7207 is one of its attenuated strains.SL7207 was first made for bacterial vaccine development and its therapeutic efficacy and safety for hepatoellular carcinoma has not been characterized.In this study,the inhibitory ability of SL 7207-lux on human hepatoma HepG2 cells was tested in vitro and in vivo.A bacterial luminescent gene cluster(lux CDA BE)was transfected into SL7207 to better monitor the invasion of the bacteria.The results show that SL7207-lux can rapidly enter HepG2 cells and localize in the cytoplasm.This invasion represses ell proliferation and induces apoptosis.In vivo real-time invasion studies showed that the bacteria gradually accumulate in the tumor.This enrichment was confirmed by anatomic observation at 5 days after inoculation.About 40%of tumor growth was inhibited by SL7207-lxx at 34 days post-treatment without significant loss of body weight.The area of necrosis of tumor tissue was clearly increased in the treated group.Bacterial quantification showed that the number of colony-forming units per gram of bacteria within tumor tissue was approximately 1000-fold higher than that of liver and spleen.These data suggest that attenuated S.typhimurium strain SL7207 has potential for the treatment of cancers.
