好题精选Ocean Vuongs The Emperor of Gladness provides a clear window into human connection in modern society.Following his first prize⁃winning novel,this new work establishes Vuong as a leading writer by turning perso...好题精选Ocean Vuongs The Emperor of Gladness provides a clear window into human connection in modern society.Following his first prize⁃winning novel,this new work establishes Vuong as a leading writer by turning personal hardships into shared truths.It serves as both a deeply moving story and a useful guide for understanding community bonds in lonely times.展开更多
In order to verify the properties of the light propagating through a gradient-index （GRIN） fibre probe for optical coherence tomography （OCT）, numerical simulation using the optical software GLAD is carried out. F...In order to verify the properties of the light propagating through a gradient-index （GRIN） fibre probe for optical coherence tomography （OCT）, numerical simulation using the optical software GLAD is carried out. Firstly, the model of the GRIN fibre probe is presented, which is consisted of a single mode fibre （SMF）, a no-core fibre （NCF）, a GRIN fibre lens and an air path. Then, the software GLAD is adopted to numerically investigate how the lengths of the NCF and the GRIN fibre lens influence the performance of the Gaussian beam focusing through the GRIN fibre probe. The simulation results are well consistent with the experimental ones, showing that the GLAD based numerical simulation technique is an intuitive and effective tool for the verification of the properties of the light propagation. In this paper, we find that on the conditions of a constant GRIN fibre lens length of 0.1 mm and an NCF length of 0.36 mm, the working distance of the probe will be 0.75 mm and the focus spot size is 32 μm.展开更多
Catalytic nanomotors are nano-to-micrometer-sized actuators that carry an on-board catalyst and convert local chemical fuel in solution into mechanical work. The location of this catalyst as well as the geometry of th...Catalytic nanomotors are nano-to-micrometer-sized actuators that carry an on-board catalyst and convert local chemical fuel in solution into mechanical work. The location of this catalyst as well as the geometry of the structure dictate the swimming behaviors exhibited. The nanomotors can occur naturally in organic molecules, combine natural and artificial parts to form hybrid nanomotors or be purely artificial. Fabrication techniques consist of template directed electroplating, lithography, physical vapor deposition, and other advanced growth methods. Various physical and chemical propulsion mechanisms have been proposed to explain the motion behaviors including diffusiophoresis, bubble propulsion, interracial tension gradients, and self-electrophoresis. The control and manipulation based upon external fields, catalytic alloys, and motion control through thermal modulation are discussed as well. Catalytic nanomotors represent an exciting technological challenge with the end goal being practical functional nanomachines that can perform a variety of tasks at the nanoscale.展开更多
The effect of annealing on vertically aligned TiO2 NWs deposited by glancing angle deposition（GLAD）method on Si substrate using pressed and sintered TiO2 pellets as source material is studied.The FE-SEM images revea...The effect of annealing on vertically aligned TiO2 NWs deposited by glancing angle deposition（GLAD）method on Si substrate using pressed and sintered TiO2 pellets as source material is studied.The FE-SEM images reveal the retention of vertically aligned NWs on Si substrate after annealing process.The EDS analysis of TiO2NWs sample annealed at 600 ℃ in air for 1 h shows the higher weight percentage ratio of ～2.6（i.e.,72.27%oxygen and 27.73%titanium）.The XRD pattern reveals that the polycrystalline nature of anatase TiO2 dominates the annealed NWs sample.The electrical characteristics of Al/TiO2-NWs/TiO2-TF/p-Si（NW device） and Al/TiO2-TF/p-Si（TF device） based on annealed samples are compared.It is riveting to observe a lower leakage current of ～1.32 × 10^-7 A/cm^2 at ＋1 V with interface trap density of-6.71 × 10^11eV^-1cm^-2 in NW device compared to ～2.23 × 10^-2 A/cm^2 in TF device.The dominant leakage mechanism is investigated to be generally Schottky emission;however Poole-Frenkel emission also takes place during high reverse bias beyond 4 V for NWs and 3 V for TF device.展开更多
文摘好题精选Ocean Vuongs The Emperor of Gladness provides a clear window into human connection in modern society.Following his first prize⁃winning novel,this new work establishes Vuong as a leading writer by turning personal hardships into shared truths.It serves as both a deeply moving story and a useful guide for understanding community bonds in lonely times.
基金supported by the International Cooperation Project of Shanghai Science and Technology Committee,China(Grant No.09530708700)
文摘In order to verify the properties of the light propagating through a gradient-index （GRIN） fibre probe for optical coherence tomography （OCT）, numerical simulation using the optical software GLAD is carried out. Firstly, the model of the GRIN fibre probe is presented, which is consisted of a single mode fibre （SMF）, a no-core fibre （NCF）, a GRIN fibre lens and an air path. Then, the software GLAD is adopted to numerically investigate how the lengths of the NCF and the GRIN fibre lens influence the performance of the Gaussian beam focusing through the GRIN fibre probe. The simulation results are well consistent with the experimental ones, showing that the GLAD based numerical simulation technique is an intuitive and effective tool for the verification of the properties of the light propagation. In this paper, we find that on the conditions of a constant GRIN fibre lens length of 0.1 mm and an NCF length of 0.36 mm, the working distance of the probe will be 0.75 mm and the focus spot size is 32 μm.
基金Acknowledgements We acknowledge the financial support from the National Science Foundation under Contract No. CMMI-0726770 and ECCS-0901141.
文摘Catalytic nanomotors are nano-to-micrometer-sized actuators that carry an on-board catalyst and convert local chemical fuel in solution into mechanical work. The location of this catalyst as well as the geometry of the structure dictate the swimming behaviors exhibited. The nanomotors can occur naturally in organic molecules, combine natural and artificial parts to form hybrid nanomotors or be purely artificial. Fabrication techniques consist of template directed electroplating, lithography, physical vapor deposition, and other advanced growth methods. Various physical and chemical propulsion mechanisms have been proposed to explain the motion behaviors including diffusiophoresis, bubble propulsion, interracial tension gradients, and self-electrophoresis. The control and manipulation based upon external fields, catalytic alloys, and motion control through thermal modulation are discussed as well. Catalytic nanomotors represent an exciting technological challenge with the end goal being practical functional nanomachines that can perform a variety of tasks at the nanoscale.
文摘The effect of annealing on vertically aligned TiO2 NWs deposited by glancing angle deposition（GLAD）method on Si substrate using pressed and sintered TiO2 pellets as source material is studied.The FE-SEM images reveal the retention of vertically aligned NWs on Si substrate after annealing process.The EDS analysis of TiO2NWs sample annealed at 600 ℃ in air for 1 h shows the higher weight percentage ratio of ～2.6（i.e.,72.27%oxygen and 27.73%titanium）.The XRD pattern reveals that the polycrystalline nature of anatase TiO2 dominates the annealed NWs sample.The electrical characteristics of Al/TiO2-NWs/TiO2-TF/p-Si（NW device） and Al/TiO2-TF/p-Si（TF device） based on annealed samples are compared.It is riveting to observe a lower leakage current of ～1.32 × 10^-7 A/cm^2 at ＋1 V with interface trap density of-6.71 × 10^11eV^-1cm^-2 in NW device compared to ～2.23 × 10^-2 A/cm^2 in TF device.The dominant leakage mechanism is investigated to be generally Schottky emission;however Poole-Frenkel emission also takes place during high reverse bias beyond 4 V for NWs and 3 V for TF device.
