Three-dimensional tracking of submicron particles in flows in a micro-channel was carried out using in-line holographic microscopy.A fixed single 0.5 μm fluorescent particle was identified and isolated from dust part...Three-dimensional tracking of submicron particles in flows in a micro-channel was carried out using in-line holographic microscopy.A fixed single 0.5 μm fluorescent particle was identified and isolated from dust particles or overlapped particle pair using the laser induced fluorescent(LIF) method.Then in-line microscopic holograms of the fixed single particle were obtained at different positions on the optical axis,i.e.the defocus distances.The holograms of the single particle were used as the model templates with the known defocus distances.The particles in the in-line microscopic holograms of flow in the microchannel were then identified and located to obtain their two-dimensional positions.The defocus distances of those particles were determined by matching each hologram pattern to one of the model templates obtained in the single particle test.Finally the three-dimensional position and velocity of each particle were obtained.展开更多
ZnO nanoparticles were first encapsulated in submicron PS hollow microspheres through two-step swelling process of core-shell structured PMMA/PS （PMMA： polymethyl methao- rylate） microspheres in acid-alkali solutio...ZnO nanoparticles were first encapsulated in submicron PS hollow microspheres through two-step swelling process of core-shell structured PMMA/PS （PMMA： polymethyl methao- rylate） microspheres in acid-alkali solution, and the ZnO precursors, i.e. the ethanol solu- tions of （CHaCOO）2Zn and LiOH. The transmission electron microscope, X-ray diffraction, and thermogravimetric analysis results show that the feeding order of ethanol solutions of （CH3COO）2Zn and LiOH in the second swelling step has great influence on the loading efficiency and the size of ZnO nanoparticles, but little on their crystal form. The photolumi- nescence and UV-Vis absorption behavior of ZnO/PS microspheres show that the PS shell can effectively avoid the fluorescence quenching effect.展开更多
A supercritical hydrothermal method was employed to prepare sub-micrometer LiFePO4particles with high purity and crystallinity.The structure and morphology of LiFePO4particles were characterized by X-ray diffraction a...A supercritical hydrothermal method was employed to prepare sub-micrometer LiFePO4particles with high purity and crystallinity.The structure and morphology of LiFePO4particles were characterized by X-ray diffraction and scanning electron microscope.The electrochemical tests were carried out to determine the reversible capacity,rate and cycling performance of the LiFePO4particles as cathode material for lithium ion battery.Experimental results show that solvent and calcining time have significant effects on purity,size and morphology of LiFePO4particles.Mixed solvent contained deionized water and ethanol is conducive to synthesize smaller and more uniform particles.The size of LiFePO4particles as-prepared is about 100-300 nm.The specific discharge capacities of the LiFePO4particles are 151.3 and 128.0 mA·h·g?1 after first cycle at the rates of 0.1 and 1.0 C,respectively.It retains 95.0%of the initial capacity after 100 cycles at 1.0 C.展开更多
In a lab of the CAS Institute of Process Engineering（IPE）in Beijing,Winifred Uduak Anake,a visiting woman scientist from Covenant University.Nigeria was dashing to finish testing the 100 plus samples she collected f...In a lab of the CAS Institute of Process Engineering（IPE）in Beijing,Winifred Uduak Anake,a visiting woman scientist from Covenant University.Nigeria was dashing to finish testing the 100 plus samples she collected from her home country.＂1 am trying to find out the type and amount of hazardous trace metals bound to the tiny particles trapped on the filters,＂she explained：＂out of worries about their possible threat to human health.＂Before concluding her three-month stay she needed to complete examining the morphology of the particles,total trace metals,展开更多
基金Supported by the National Natural Science Foundation of China (50736002,61072005)Changjiang Scholars and Innovative Team Development Plan (IRT0957)
文摘Three-dimensional tracking of submicron particles in flows in a micro-channel was carried out using in-line holographic microscopy.A fixed single 0.5 μm fluorescent particle was identified and isolated from dust particles or overlapped particle pair using the laser induced fluorescent(LIF) method.Then in-line microscopic holograms of the fixed single particle were obtained at different positions on the optical axis,i.e.the defocus distances.The holograms of the single particle were used as the model templates with the known defocus distances.The particles in the in-line microscopic holograms of flow in the microchannel were then identified and located to obtain their two-dimensional positions.The defocus distances of those particles were determined by matching each hologram pattern to one of the model templates obtained in the single particle test.Finally the three-dimensional position and velocity of each particle were obtained.
文摘ZnO nanoparticles were first encapsulated in submicron PS hollow microspheres through two-step swelling process of core-shell structured PMMA/PS （PMMA： polymethyl methao- rylate） microspheres in acid-alkali solution, and the ZnO precursors, i.e. the ethanol solu- tions of （CHaCOO）2Zn and LiOH. The transmission electron microscope, X-ray diffraction, and thermogravimetric analysis results show that the feeding order of ethanol solutions of （CH3COO）2Zn and LiOH in the second swelling step has great influence on the loading efficiency and the size of ZnO nanoparticles, but little on their crystal form. The photolumi- nescence and UV-Vis absorption behavior of ZnO/PS microspheres show that the PS shell can effectively avoid the fluorescence quenching effect.
文摘A supercritical hydrothermal method was employed to prepare sub-micrometer LiFePO4particles with high purity and crystallinity.The structure and morphology of LiFePO4particles were characterized by X-ray diffraction and scanning electron microscope.The electrochemical tests were carried out to determine the reversible capacity,rate and cycling performance of the LiFePO4particles as cathode material for lithium ion battery.Experimental results show that solvent and calcining time have significant effects on purity,size and morphology of LiFePO4particles.Mixed solvent contained deionized water and ethanol is conducive to synthesize smaller and more uniform particles.The size of LiFePO4particles as-prepared is about 100-300 nm.The specific discharge capacities of the LiFePO4particles are 151.3 and 128.0 mA·h·g?1 after first cycle at the rates of 0.1 and 1.0 C,respectively.It retains 95.0%of the initial capacity after 100 cycles at 1.0 C.
文摘In a lab of the CAS Institute of Process Engineering（IPE）in Beijing,Winifred Uduak Anake,a visiting woman scientist from Covenant University.Nigeria was dashing to finish testing the 100 plus samples she collected from her home country.＂1 am trying to find out the type and amount of hazardous trace metals bound to the tiny particles trapped on the filters,＂she explained：＂out of worries about their possible threat to human health.＂Before concluding her three-month stay she needed to complete examining the morphology of the particles,total trace metals,
