The self-assembly of diblock copolymers confined around one square-shaped particle is studied systematically within two-dimensional self-consistent field theory（SCFT）.In this model,we assume that the thin block copo...The self-assembly of diblock copolymers confined around one square-shaped particle is studied systematically within two-dimensional self-consistent field theory（SCFT）.In this model,we assume that the thin block copolymer film is confined in the vicinity of a square-shaped particle by a homopolymer melt,which is equivalent to the poor solvents.Multiple sequences of square-shaped particle-induced copolymer aggregates with different shapes and self-assembled internal morphologies are predicted as functions of the particle size,the structural portion of the copolymer,and the volume fraction of the copolymer.A rich variety of aggregates are found with complex internal self-assembled morphologies including complex structures of the vesicle,with one or several inverted micelle surrounded by the outer monolayer with the particle confined in the core.These results demonstrate that the assemblies of diblock copolymers formed around the square-shaped particle in poor solvents are of immediate interest to the assembly of copolymer and the morphology of biomembrane in the confined environment,as well as to the transitions of vesicles to micelles.展开更多
than 2.2, the electromagnetic pressure acting on melt can be simply expressed as Pm =B^2/wμ, and the melt shape would be known only by measuring the distribution of magnetic flux density. As a is small and makes the ...than 2.2, the electromagnetic pressure acting on melt can be simply expressed as Pm =B^2/wμ, and the melt shape would be known only by measuring the distribution of magnetic flux density. As a is small and makes the ratio a/8 less than 2.2, the melt shape and electromagnetic pressure for confining and shaping are determined not only by magnetic flux density B but also by melt thickness a, electromagnetic parameter μγ and current frequency f. In this paper, an equation used to calculate electromagnetic pressure acting on 'thin plate-form melt' is brought forward. The equation gives a precise relationship between electromagnetic pressure factor p and melt thickness a, electromagnetic parameter μγ and current frequency f.展开更多
Dual frequency electromagnetic confinement and shaping (EMCS) makes it easier to adjust and control the shaping temperature field and magnetic field than single frequency EMCS. The shaping stability and temperature fi...Dual frequency electromagnetic confinement and shaping (EMCS) makes it easier to adjust and control the shaping temperature field and magnetic field than single frequency EMCS. The shaping stability and temperature field of the dual frequency EMCS were investigated. The results indicate that to shape stably, the upper liquid/solid interface should be in appropriate position and the lower liquid/solid interface must be above the critical position. The current of heating induction coil and the drawing speed of sample affect the shaping temperature and its peak position, while the current of the shaping induction coil only influences the shaping temperature. During EMCS, the speed of shaped sample affects not the height of the molten metal, but the temperature of molten metal. The height of the molten metal for steady shaping was about 15 mm in the experimental conditions. Several stainless steel plate-like parts with high width to thickness ratio (≥3.5) and directional structure were obtained.展开更多
Silica whispering gallery mode（WGM） microcavities were fabricated by the buffered oxide etcher and potassium hydroxide wet etching technique without any subsequent chemical or laser treatments. The silicon pedestal ...Silica whispering gallery mode（WGM） microcavities were fabricated by the buffered oxide etcher and potassium hydroxide wet etching technique without any subsequent chemical or laser treatments. The silicon pedestal underneath was an octagonal pyramid, thus providing a pointed connection area with the top silica microdisk while weakly influencing the resonance modes. The sidewalls of our microdisks were wedge shaped, which was believed to be an advantage for the mode confinement. Efficient coupling from and to the 60 μm diameter microdisk structure was achieved using tapered optical fibres, exhibiting a quality factor of 1.5×10^4 near a wavelength of 1550 nm. Many resonance modes were observed, and double transverse electric modes were identified by theoretical calculations. The quality factor of the microdisks was also analysed to deduce the cavity roughness. The wet etching technique provides a more convenient avenue to fabricate WGM microdisks than conventional fabrication methods.展开更多
Through doping liquid crystals into the core region, we propose a kind of seven-core photonic crystal fiber（PCF）which can achieve mode shaping and temperature sensing simultaneously in the communication window of1.1...Through doping liquid crystals into the core region, we propose a kind of seven-core photonic crystal fiber（PCF）which can achieve mode shaping and temperature sensing simultaneously in the communication window of1.1–1.7 μm. To the best of our knowledge, this is the first time that the function of seven-core PCFs as temperature sensors is investigated. By using the full vectorial finite element method, the characteristics of the fiber with the temperature, such as the effective mode area, the waveguide dispersion, and the confinement loss, are analyzed. This kind of PCF can be competitive in providing temperature sensing in multi-core PCF lasers.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.20804060)the Research Foundation of Chongqing University of Science and Technology,China(Grant No.CK2013B16)
文摘The self-assembly of diblock copolymers confined around one square-shaped particle is studied systematically within two-dimensional self-consistent field theory（SCFT）.In this model,we assume that the thin block copolymer film is confined in the vicinity of a square-shaped particle by a homopolymer melt,which is equivalent to the poor solvents.Multiple sequences of square-shaped particle-induced copolymer aggregates with different shapes and self-assembled internal morphologies are predicted as functions of the particle size,the structural portion of the copolymer,and the volume fraction of the copolymer.A rich variety of aggregates are found with complex internal self-assembled morphologies including complex structures of the vesicle,with one or several inverted micelle surrounded by the outer monolayer with the particle confined in the core.These results demonstrate that the assemblies of diblock copolymers formed around the square-shaped particle in poor solvents are of immediate interest to the assembly of copolymer and the morphology of biomembrane in the confined environment,as well as to the transitions of vesicles to micelles.
基金National Natural Science Foundation! No. 59995440National PostDoctor Science Foundation !([19971 11)of China
文摘than 2.2, the electromagnetic pressure acting on melt can be simply expressed as Pm =B^2/wμ, and the melt shape would be known only by measuring the distribution of magnetic flux density. As a is small and makes the ratio a/8 less than 2.2, the melt shape and electromagnetic pressure for confining and shaping are determined not only by magnetic flux density B but also by melt thickness a, electromagnetic parameter μγ and current frequency f. In this paper, an equation used to calculate electromagnetic pressure acting on 'thin plate-form melt' is brought forward. The equation gives a precise relationship between electromagnetic pressure factor p and melt thickness a, electromagnetic parameter μγ and current frequency f.
文摘Dual frequency electromagnetic confinement and shaping (EMCS) makes it easier to adjust and control the shaping temperature field and magnetic field than single frequency EMCS. The shaping stability and temperature field of the dual frequency EMCS were investigated. The results indicate that to shape stably, the upper liquid/solid interface should be in appropriate position and the lower liquid/solid interface must be above the critical position. The current of heating induction coil and the drawing speed of sample affect the shaping temperature and its peak position, while the current of the shaping induction coil only influences the shaping temperature. During EMCS, the speed of shaped sample affects not the height of the molten metal, but the temperature of molten metal. The height of the molten metal for steady shaping was about 15 mm in the experimental conditions. Several stainless steel plate-like parts with high width to thickness ratio (≥3.5) and directional structure were obtained.
基金Project supported by the Postdoctoral Science Foundation of China(Grant No.2015M582041)the Special Project on the Integration of Industry,Education and Research of Aviation Industry Corporation of China
文摘Silica whispering gallery mode（WGM） microcavities were fabricated by the buffered oxide etcher and potassium hydroxide wet etching technique without any subsequent chemical or laser treatments. The silicon pedestal underneath was an octagonal pyramid, thus providing a pointed connection area with the top silica microdisk while weakly influencing the resonance modes. The sidewalls of our microdisks were wedge shaped, which was believed to be an advantage for the mode confinement. Efficient coupling from and to the 60 μm diameter microdisk structure was achieved using tapered optical fibres, exhibiting a quality factor of 1.5×10^4 near a wavelength of 1550 nm. Many resonance modes were observed, and double transverse electric modes were identified by theoretical calculations. The quality factor of the microdisks was also analysed to deduce the cavity roughness. The wet etching technique provides a more convenient avenue to fabricate WGM microdisks than conventional fabrication methods.
基金supported by the Natural Science Foundation of China with under Grant No.61475029
文摘Through doping liquid crystals into the core region, we propose a kind of seven-core photonic crystal fiber（PCF）which can achieve mode shaping and temperature sensing simultaneously in the communication window of1.1–1.7 μm. To the best of our knowledge, this is the first time that the function of seven-core PCFs as temperature sensors is investigated. By using the full vectorial finite element method, the characteristics of the fiber with the temperature, such as the effective mode area, the waveguide dispersion, and the confinement loss, are analyzed. This kind of PCF can be competitive in providing temperature sensing in multi-core PCF lasers.
