Three sample preparation techniques, focused ion beam （FIB）, ion beam （IB） etching, and ultramicrotomy （UM） were used in comparison to analyze the interphase of carbon fiber ＇epoxy composites using transmission...Three sample preparation techniques, focused ion beam （FIB）, ion beam （IB） etching, and ultramicrotomy （UM） were used in comparison to analyze the interphase of carbon fiber ＇epoxy composites using transmission electron microscopy. An intact interphase with a relatively uniform thickness was obtained by FIB. and detailed chemical analysis of the interphase was investigated by electron energy loss spectroscopy. It shows that the interphase region is 200 mn wide with an increasing oxygen-to-carbon ratio from 10% to 19% and an almost constant nitrogen-to-carbon ratio of about 3%. However, gallium implantation of FIB tends to hinder fine structure analysis of the interphase. For IB etching, the interphase region is observed with transition morphology frona amorphous resin to nano-crystalline carbon fiber, but the uneven sample thickness brings difficulty for quantitative chemical analysis. Moreover, UM tends to cause damage and/or deformation on the interphase. These results are meaningful for in-depth understanding on the interphase characteristic of carbon fiber composites.展开更多
High power and high-slope efficiency 650nm band real-refractive-index ridge w aveguide AlGaInP laser diodes with compressive strained MQW active layer are for med by pure Ar ion beam etching process.Symmetric laser me...High power and high-slope efficiency 650nm band real-refractive-index ridge w aveguide AlGaInP laser diodes with compressive strained MQW active layer are for med by pure Ar ion beam etching process.Symmetric laser mesas with high perpendi cularity,which are impossible to obtain by traditional wet etching method due to the use of a 15°-misoriented substrate,are obtained by this dry etching metho d.Laser diodes with 4μm wide,600μm long and 10%/90% coat are fabricated.Th e typical threshold current of these devices is 46mA at room temperature,and a s table fundamental-mode operation over 40mW is obtained.Very high slope efficien cy of 1.4W/A at 10mW and 1.1W/A at 40mW are realized.展开更多
[Objective] The aim was to study the mechanism of the removal effect of methylene blue(MB) by rice husk ash(RHA).[Method] The effects of contact time and pH on the adsorption of MB by rice husk ash were investigated,a...[Objective] The aim was to study the mechanism of the removal effect of methylene blue(MB) by rice husk ash(RHA).[Method] The effects of contact time and pH on the adsorption of MB by rice husk ash were investigated,and the mechanism was discussed.[Result] RHA exhibited a remarkable ability on the adsorption of MB.The process of adsorption reached the equilibrium after 30 min,at about pH 9.The adsorption effect was explored with the aid of ion beam etching technique,which displayed that there were two main adsorption manners.One was the electrostatic interactions,through which the negatively charged RHA could adsorb the positively charged MB,the other was the porous effect due to the huge specific surface area of the micro/nano-scale porous silica in RHA,and MB could be adsorbed and deposited into the pores.[Conclusion] RHA could be used in the treatment of textile wastewater.Ion beam technology might be used as an effective way to investigate the adsorption effect.展开更多
We report on the fabrication of the lO-mm-long lithium niobate ridge waveguide and its supercontinuum gen- eration at near-visible wavelengths （around 800hm）. The waveguides are fabricated by a combination of MeV co...We report on the fabrication of the lO-mm-long lithium niobate ridge waveguide and its supercontinuum gen- eration at near-visible wavelengths （around 800hm）. The waveguides are fabricated by a combination of MeV copper ion implantation followed by wet etching in a proton exchanged lithium niobate planar waveguide. Using a mode-locked Ti：sapphire laser with a central wavelength of 800nm, the generated broadest supereontinuum through the ridge waveguides spans 302 nm （at -30 dB points）, from 693 to 995 nm. Temporal coherence proper- ties of the supercontinuum are experimentally studied by a Michelson interferometer and the coherence length of the broadest supercontinuum is measured to be 5.2 μm. Our results offer potential for a compact and integrated supercontinuum source for applications including bio-imaging, spectroscopy and optical communication.展开更多
Titanium and titanium alloys are currently being used for clinical biomedical applications due to their high strength, corrosion resistance and elastic modulus. The Ti-30Ta alloy has gotten extensive application as th...Titanium and titanium alloys are currently being used for clinical biomedical applications due to their high strength, corrosion resistance and elastic modulus. The Ti-30Ta alloy has gotten extensive application as the important biomedical materials. The substrate surface of the Ti-30Ta alloy was altered either by chemical or topographical surface modification. The biocompatibility of an implant is closely related to its surface properties. Thus surface modification is one of effective methods for improving the biocompatibility of implants. The development status of biomedical materials has been summarized firstly, the biomedical application. In this study Ti-30Ta alloy surface was investigate as-casting (Group 1) modified with alkaline and heat-treatments in NaOH with 1.5M at 60°C for 24 hrs (Group 2), alkaline and heat-treatments with SBF-coatings by immersion in NaOH and SBFX5 for 24hrs (Group 3), anodization process was performed in an electrolyte solution containing HF (48%) and H2SO4 (98%) with the addition of 5% dimethyl sulfoxide (DMSO) 35V for 40 min (Group 4) and ion beam etching with 1200 eV ions with a beam current of 200 mA for a 3 hrs etch (Group 5). SEM was used to investigate the topography, EDS the chemical composition, and surface energy was evaluate with water contact angle measurement. SEM results show different structure on the surface for each group. EDS spectra identified similarity on Group 1, 4 and 5. The results indicate for group 2 an amorphous sodium tantalate hydrogel layer on the substrate surface and for group 3 the apatite nucleation on substrate surface. The Group 4 shows unorganized and vertically nanotubes and Group 5 shows a little alteration in the topography on the substrate surfaces. Overall the contact angle shows Group 5 the most hydrophobic and Group 4 the most hydrophilic. The study indicates Group 3 and 4 with potential for biomedical application. The next step the authors need to spend more time to study group 3 and 4 in the biomedical sciences.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 51273007)the Program for New Century Excellent Talents in University of China (NCET)
文摘Three sample preparation techniques, focused ion beam （FIB）, ion beam （IB） etching, and ultramicrotomy （UM） were used in comparison to analyze the interphase of carbon fiber ＇epoxy composites using transmission electron microscopy. An intact interphase with a relatively uniform thickness was obtained by FIB. and detailed chemical analysis of the interphase was investigated by electron energy loss spectroscopy. It shows that the interphase region is 200 mn wide with an increasing oxygen-to-carbon ratio from 10% to 19% and an almost constant nitrogen-to-carbon ratio of about 3%. However, gallium implantation of FIB tends to hinder fine structure analysis of the interphase. For IB etching, the interphase region is observed with transition morphology frona amorphous resin to nano-crystalline carbon fiber, but the uneven sample thickness brings difficulty for quantitative chemical analysis. Moreover, UM tends to cause damage and/or deformation on the interphase. These results are meaningful for in-depth understanding on the interphase characteristic of carbon fiber composites.
文摘High power and high-slope efficiency 650nm band real-refractive-index ridge w aveguide AlGaInP laser diodes with compressive strained MQW active layer are for med by pure Ar ion beam etching process.Symmetric laser mesas with high perpendi cularity,which are impossible to obtain by traditional wet etching method due to the use of a 15°-misoriented substrate,are obtained by this dry etching metho d.Laser diodes with 4μm wide,600μm long and 10%/90% coat are fabricated.Th e typical threshold current of these devices is 46mA at room temperature,and a s table fundamental-mode operation over 40mW is obtained.Very high slope efficien cy of 1.4W/A at 10mW and 1.1W/A at 40mW are realized.
基金Supported by National Natural Science Foundation of China (No.10975154)State Key Lab of Electroanalytical Chemistry,Changchun Institute of Applied Chemistry,CAS (SKLEA 201104)
文摘[Objective] The aim was to study the mechanism of the removal effect of methylene blue(MB) by rice husk ash(RHA).[Method] The effects of contact time and pH on the adsorption of MB by rice husk ash were investigated,and the mechanism was discussed.[Result] RHA exhibited a remarkable ability on the adsorption of MB.The process of adsorption reached the equilibrium after 30 min,at about pH 9.The adsorption effect was explored with the aid of ion beam etching technique,which displayed that there were two main adsorption manners.One was the electrostatic interactions,through which the negatively charged RHA could adsorb the positively charged MB,the other was the porous effect due to the huge specific surface area of the micro/nano-scale porous silica in RHA,and MB could be adsorbed and deposited into the pores.[Conclusion] RHA could be used in the treatment of textile wastewater.Ion beam technology might be used as an effective way to investigate the adsorption effect.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61575129 and 11375105the Postdoctoral Science Foundation of China under Grant No 2016M602511+1 种基金the Shenzhen Science and Technology Planning under Grant No JCYJ20160422142912923the State Key Laboratory of Nuclear Physics and Technology,Peking University
文摘We report on the fabrication of the lO-mm-long lithium niobate ridge waveguide and its supercontinuum gen- eration at near-visible wavelengths （around 800hm）. The waveguides are fabricated by a combination of MeV copper ion implantation followed by wet etching in a proton exchanged lithium niobate planar waveguide. Using a mode-locked Ti：sapphire laser with a central wavelength of 800nm, the generated broadest supereontinuum through the ridge waveguides spans 302 nm （at -30 dB points）, from 693 to 995 nm. Temporal coherence proper- ties of the supercontinuum are experimentally studied by a Michelson interferometer and the coherence length of the broadest supercontinuum is measured to be 5.2 μm. Our results offer potential for a compact and integrated supercontinuum source for applications including bio-imaging, spectroscopy and optical communication.
基金Brazilian agencies CNPq via grant Doctored sandwich (201271/2010-9) Fapesp project number 2010/ 10174-8 and 2010/07231-0
文摘Titanium and titanium alloys are currently being used for clinical biomedical applications due to their high strength, corrosion resistance and elastic modulus. The Ti-30Ta alloy has gotten extensive application as the important biomedical materials. The substrate surface of the Ti-30Ta alloy was altered either by chemical or topographical surface modification. The biocompatibility of an implant is closely related to its surface properties. Thus surface modification is one of effective methods for improving the biocompatibility of implants. The development status of biomedical materials has been summarized firstly, the biomedical application. In this study Ti-30Ta alloy surface was investigate as-casting (Group 1) modified with alkaline and heat-treatments in NaOH with 1.5M at 60°C for 24 hrs (Group 2), alkaline and heat-treatments with SBF-coatings by immersion in NaOH and SBFX5 for 24hrs (Group 3), anodization process was performed in an electrolyte solution containing HF (48%) and H2SO4 (98%) with the addition of 5% dimethyl sulfoxide (DMSO) 35V for 40 min (Group 4) and ion beam etching with 1200 eV ions with a beam current of 200 mA for a 3 hrs etch (Group 5). SEM was used to investigate the topography, EDS the chemical composition, and surface energy was evaluate with water contact angle measurement. SEM results show different structure on the surface for each group. EDS spectra identified similarity on Group 1, 4 and 5. The results indicate for group 2 an amorphous sodium tantalate hydrogel layer on the substrate surface and for group 3 the apatite nucleation on substrate surface. The Group 4 shows unorganized and vertically nanotubes and Group 5 shows a little alteration in the topography on the substrate surfaces. Overall the contact angle shows Group 5 the most hydrophobic and Group 4 the most hydrophilic. The study indicates Group 3 and 4 with potential for biomedical application. The next step the authors need to spend more time to study group 3 and 4 in the biomedical sciences.
