Fatigue cutting is a new approach for separating material. Man-made fatigue can be realized by applying a rotating bending load to a notched bar. To better utilize the new method, laser treatment is adopted in this st...Fatigue cutting is a new approach for separating material. Man-made fatigue can be realized by applying a rotating bending load to a notched bar. To better utilize the new method, laser treatment is adopted in this study. After laser radiation at the notch root, the fatigue cycle of the bar drops dramatically. Based on the experimental result, we draw the conclusion that the fatigue of the bar is influenced by the shape of the hardened area. A hardened area that has a small axial dimension and a relatively large radial dimension facilitates the fatigue. The desirable hardened area can be obtained by controlling the laser treatment parameters.展开更多
AIM： To prepare a complex of hyaluronic acid （HA） and phospholipids （PL）, and study the improvement effect of PL on the oral absorption of HA. METHODS： The complex of HA-PL （named Haplex） was prepared by film ...AIM： To prepare a complex of hyaluronic acid （HA） and phospholipids （PL）, and study the improvement effect of PL on the oral absorption of HA. METHODS： The complex of HA-PL （named Haplex） was prepared by film dispersion and sonication method, its physico-chemical properties were identified by infrared spectra and differential scanning calorimetry （DSC）. The oral absorption of Haplex was studied. Thirty-two healthy rats were divided into 4 groups randomly： （1） a normal saline （NS） control group; （2） an HA group; （3） a mixture group and （4） a Haplex group. After intragastric administration, the concentration of HA in serum was determined. RESULTS： The physico-chemical properties of Haplex were different from HA or PL or their mixture. After Haplex was administered to rats orally, the serum concentration of HA was increased when compared with the mixture or HA control groups from 4 h to 10 h （P 〈 0.05）. The AAUCo-12, of Haplex was also greater than that of the other three groups （P 〈 0.05）. CONCLUSION： The method of film dispersion and sonication can prepare HA and PL complex, and PL can enhance the oral absorption of exogenous HA.展开更多
The ability to arbitrarily regulate semiconductor interfaces provides the most effective way to modulate the performance of optoelectronic devices. However, less work has been reported on piezo-modulated interface eng...The ability to arbitrarily regulate semiconductor interfaces provides the most effective way to modulate the performance of optoelectronic devices. However, less work has been reported on piezo-modulated interface engineering in all-oxide systems. In this paper, an enhanced photoresponse of an all-oxide Cu2O/ZnO heterojunction was obtained by taking advantage of the piezotronic effect. The illumination density-dependent piezoelectric modulation ability was also comprehensively investigated. An 18.6% enhancement of photoresponse was achieved when applying a a-0.88% compressive strain. Comparative experiments confirmed that this enhancement could be interpreted in terms of the band modification induced by interfacial piezoelectric polarization. The positive piezopotential generated at the ZnO side produces an increase in space charge region in Cu2O, thus providing an extra driving force to separate the excitons more efficiently under illumination. Our research provides a promising method to boost the performance of optoelectronics without altering the interface structure and could be extended to other metal oxide devices.展开更多
A novel photocatalytic reactor was developed to remove （1,1-bis（4-chlorophenyl）-2,2,2-trichloroethane） （DDT） from water. In the reactor, a cenosphere was used to support TiO2 film made by means of sol-gel. Becau...A novel photocatalytic reactor was developed to remove （1,1-bis（4-chlorophenyl）-2,2,2-trichloroethane） （DDT） from water. In the reactor, a cenosphere was used to support TiO2 film made by means of sol-gel. Because the cenospheres were coated with TiO2, their specific gravity was slightly increased from the original 0.6-0.8 to 0.8-0.9, so that they were able to be suspended in water. With the mixed operation of a bubbler, the water in the reactor was in a well-fluidized state. The bottom of the reactor is a sand filter bed, which can be used to prevent the photocatalyst from being lost. A mathematical model of the reactor has been developed in the two primary influential factors： ultraviolet （UV） light intensity and photocatalyst concentration. With such a model, the reactor can be designed more reasonably.展开更多
The measurement of emissions from the window material of sapphire was performed through multi-wavelength pyrometer and spontaneous spectroscopic techniques in the pressure range of 40 -120 GPa. The results showed that...The measurement of emissions from the window material of sapphire was performed through multi-wavelength pyrometer and spontaneous spectroscopic techniques in the pressure range of 40 -120 GPa. The results showed that the spectral distribution with wavelength clearly fit well with the grey-body spectrum. We have analyzed the emissions and discovered they mostly came from the shear banding, which is a typical thermal radiation. The radiance intensity changing linearly with time revealed it was a volume effect. All of the data from pyrometer can be explained by the model of Boslough＇s study, especially for pres- sures over megabar. The color temperature of shocked sapphire changing with increased stress disagrees with the computed melt curve which is likely explained by the differcnt phase structures of sapphire.展开更多
The exciton dissociation at ITO/pentacene interface is studied by means of transient photovoltage measurement.Opposite to ITO/NPB,ITO/CuPc or ITO/C60 interface where polarity change of transient photovoltage is observ...The exciton dissociation at ITO/pentacene interface is studied by means of transient photovoltage measurement.Opposite to ITO/NPB,ITO/CuPc or ITO/C60 interface where polarity change of transient photovoltage is observed,no interfacial dissociation is found at room temperature,which indicates a lack of Frenkel excitons in pentacene.Temperature-dependent photoluminescence (PL) is investigated.More like the behavior of inorganic semiconductors,the integrated PL intensity exhibits monotonic decrease with increasing temperature.A nonradiative path with characteristic activation energy of 8 meV is found to dominate at room temperature.The PL measurement also indicates that like in inorganic semiconductors,other types of excitation,for example,free carriers,could be responsible for the photoelectric processes.展开更多
The ultrafast laser-excited magnetization dynamics of ferromagnetic （FM） La0.67Sr0.33MnO3 （LSMO） thin films with BiFeO3 （BFO） coating layers grown by laser molecular beam epitaxy are investigated using the optic...The ultrafast laser-excited magnetization dynamics of ferromagnetic （FM） La0.67Sr0.33MnO3 （LSMO） thin films with BiFeO3 （BFO） coating layers grown by laser molecular beam epitaxy are investigated using the optical pump-probe technique. Uniform magnetization precessions are observed in the films under an applied external magnetic field by measuring the time-resolved magneto-optical Kerr effect. The magnetization precession frequencies of the LSMO thin films with the BFO coating layers are lower than those of uncoated LSMO films, which is attributed to the suppression of the anisotropy field induced by the exchange interaction at the interface between the antiferromagnetic order of BFO and the FM order of LSMO.展开更多
文摘Fatigue cutting is a new approach for separating material. Man-made fatigue can be realized by applying a rotating bending load to a notched bar. To better utilize the new method, laser treatment is adopted in this study. After laser radiation at the notch root, the fatigue cycle of the bar drops dramatically. Based on the experimental result, we draw the conclusion that the fatigue of the bar is influenced by the shape of the hardened area. A hardened area that has a small axial dimension and a relatively large radial dimension facilitates the fatigue. The desirable hardened area can be obtained by controlling the laser treatment parameters.
基金the Natural Science Foundation of Shandong Province, China. No. Y2005C31
文摘AIM： To prepare a complex of hyaluronic acid （HA） and phospholipids （PL）, and study the improvement effect of PL on the oral absorption of HA. METHODS： The complex of HA-PL （named Haplex） was prepared by film dispersion and sonication method, its physico-chemical properties were identified by infrared spectra and differential scanning calorimetry （DSC）. The oral absorption of Haplex was studied. Thirty-two healthy rats were divided into 4 groups randomly： （1） a normal saline （NS） control group; （2） an HA group; （3） a mixture group and （4） a Haplex group. After intragastric administration, the concentration of HA in serum was determined. RESULTS： The physico-chemical properties of Haplex were different from HA or PL or their mixture. After Haplex was administered to rats orally, the serum concentration of HA was increased when compared with the mixture or HA control groups from 4 h to 10 h （P 〈 0.05）. The AAUCo-12, of Haplex was also greater than that of the other three groups （P 〈 0.05）. CONCLUSION： The method of film dispersion and sonication can prepare HA and PL complex, and PL can enhance the oral absorption of exogenous HA.
基金Acknowledgements This work was supported by the National Major Research Program of China （2013CB932602）, Major Project of International Cooperation and Exchanges （2012DFA50990）, the Program of Introducing Talents of Discipline to Universities, National Natural Science Foundation of China （NSFC） （Nos. 51232001, 51172022, 51372023）, the Research Fund of Co-construction Pro- gram from Beijing Municipal Commission of Education, the Fundamental Research Funds for the Central Universities, and the Program for Changjiang Scholars and Innovative Research Teams in Universitiesy.
文摘The ability to arbitrarily regulate semiconductor interfaces provides the most effective way to modulate the performance of optoelectronic devices. However, less work has been reported on piezo-modulated interface engineering in all-oxide systems. In this paper, an enhanced photoresponse of an all-oxide Cu2O/ZnO heterojunction was obtained by taking advantage of the piezotronic effect. The illumination density-dependent piezoelectric modulation ability was also comprehensively investigated. An 18.6% enhancement of photoresponse was achieved when applying a a-0.88% compressive strain. Comparative experiments confirmed that this enhancement could be interpreted in terms of the band modification induced by interfacial piezoelectric polarization. The positive piezopotential generated at the ZnO side produces an increase in space charge region in Cu2O, thus providing an extra driving force to separate the excitons more efficiently under illumination. Our research provides a promising method to boost the performance of optoelectronics without altering the interface structure and could be extended to other metal oxide devices.
基金supported by the National Science and Technology Support Program of China (No. 2006BAJ08B06)the Major Projects on Control and Rectification of Water Body Pollution by Ministry of Environmental Protection (No. 2008ZX07421-002), China
文摘A novel photocatalytic reactor was developed to remove （1,1-bis（4-chlorophenyl）-2,2,2-trichloroethane） （DDT） from water. In the reactor, a cenosphere was used to support TiO2 film made by means of sol-gel. Because the cenospheres were coated with TiO2, their specific gravity was slightly increased from the original 0.6-0.8 to 0.8-0.9, so that they were able to be suspended in water. With the mixed operation of a bubbler, the water in the reactor was in a well-fluidized state. The bottom of the reactor is a sand filter bed, which can be used to prevent the photocatalyst from being lost. A mathematical model of the reactor has been developed in the two primary influential factors： ultraviolet （UV） light intensity and photocatalyst concentration. With such a model, the reactor can be designed more reasonably.
基金support provided by the National Natural Science Foundation of China (Grant Nos. 10874141,10974160 and 10299040)the Foundation of Center Universities (Grant No.SWJTU112T23)
文摘The measurement of emissions from the window material of sapphire was performed through multi-wavelength pyrometer and spontaneous spectroscopic techniques in the pressure range of 40 -120 GPa. The results showed that the spectral distribution with wavelength clearly fit well with the grey-body spectrum. We have analyzed the emissions and discovered they mostly came from the shear banding, which is a typical thermal radiation. The radiance intensity changing linearly with time revealed it was a volume effect. All of the data from pyrometer can be explained by the model of Boslough＇s study, especially for pres- sures over megabar. The color temperature of shocked sapphire changing with increased stress disagrees with the computed melt curve which is likely explained by the differcnt phase structures of sapphire.
基金supported by the Ministry of Science and Technology of China (Grant No.2009CB929200)the National Natural Science Foundation of China (Grant No.10621063)the Science and Technology Commission of Shanghai Municipality (Grant No.08JC1402300)
文摘The exciton dissociation at ITO/pentacene interface is studied by means of transient photovoltage measurement.Opposite to ITO/NPB,ITO/CuPc or ITO/C60 interface where polarity change of transient photovoltage is observed,no interfacial dissociation is found at room temperature,which indicates a lack of Frenkel excitons in pentacene.Temperature-dependent photoluminescence (PL) is investigated.More like the behavior of inorganic semiconductors,the integrated PL intensity exhibits monotonic decrease with increasing temperature.A nonradiative path with characteristic activation energy of 8 meV is found to dominate at room temperature.The PL measurement also indicates that like in inorganic semiconductors,other types of excitation,for example,free carriers,could be responsible for the photoelectric processes.
基金supported by the National Key Basic Research Program of China(Grant Nos.2014CB921001,and 2013CB328706)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(GrantNo.QYZDJ-SSW-SLH020)+1 种基金the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB07030200)the National Natural Science Foundation of China(Grant Nos.11574365,11474349,11674385,11404380,91436101,and 61275060)
文摘The ultrafast laser-excited magnetization dynamics of ferromagnetic （FM） La0.67Sr0.33MnO3 （LSMO） thin films with BiFeO3 （BFO） coating layers grown by laser molecular beam epitaxy are investigated using the optical pump-probe technique. Uniform magnetization precessions are observed in the films under an applied external magnetic field by measuring the time-resolved magneto-optical Kerr effect. The magnetization precession frequencies of the LSMO thin films with the BFO coating layers are lower than those of uncoated LSMO films, which is attributed to the suppression of the anisotropy field induced by the exchange interaction at the interface between the antiferromagnetic order of BFO and the FM order of LSMO.
