As the cost of quality waste paper continues to escalate in response to an increased global demand for the finite resource, loss of saleable fiber within flotation rejects becomes both environmentally and economically...As the cost of quality waste paper continues to escalate in response to an increased global demand for the finite resource, loss of saleable fiber within flotation rejects becomes both environmentally and economically unacceptable. The ability of surfactant spray technology to reduce yield loss without detriment to pulp brightness gains has been demonstrated during both laboratory- and pilot-scale flotation deinking investigations. This paper documents the successful transfer of this technology to a single flotation unit within the deinking line of a mill producing newsprint from 100% secondary fiber. Initial results suggest that the loss of fiber across the unit may be reduced by more than 50% without obvious detriment to final pulp quality.展开更多
The triangular-lattice highly birefringent photonic crystal fibers(PCFs) with gradually increasing diameter of the air holes along radial axis are put forward. The modal birefringence, dispersion and confinement loss ...The triangular-lattice highly birefringent photonic crystal fibers(PCFs) with gradually increasing diameter of the air holes along radial axis are put forward. The modal birefringence, dispersion and confinement loss of the fundamental mode are simulated by full vector Galerkin finite element method(FEM) with a perfectly matched layer(PML). The results show that this PCF can keep low confinement loss when the rings of air holes are few. When the wavelength is 1.55 μm , the birefringence, the confinement loss of quick-axis and slow-axis are 1.365×10-3, 0.017 dB/m and 0.051 dB/m, respectively. A new way is proposed to fabricate polarization-mainting fibers with high performance.展开更多
The silica fiber reinforced silica and boron nitride-based composites （SiO2f/SiO2-BN） were prepared firstly via the sol-gel method and then the urea route, and the effects of oxidation treatment on the component, st...The silica fiber reinforced silica and boron nitride-based composites （SiO2f/SiO2-BN） were prepared firstly via the sol-gel method and then the urea route, and the effects of oxidation treatment on the component, structure, mechanical and dielectric properties of the composites were investigated. The results show that the oxidation treatment at 450 ℃ will not impair the structure of boron nitride, and carbon is the main impurity with the excessive urea. The density of SiO2f/SiO2-BN composites is 1.81 g/cm3, and the flexural strength and elastic modulus are 113.9 MPa and 36.5 GPa, respectively. After oxidation treatment, the density varies to 1.80 g/cm3, and the flexural strength and elastic modulus are decreased to 58.9 MPa and 9.4 GPa, respectively. The mechanical properties of the composites are severely damaged, but they still exhibit a good toughness. The composites show excellent dielectric properties with the dielectric constant and loss tangent being 3.22 and 0.003 9, respectively, which indicates that the oxidation treatment is ineffective to improve the dielectric properties of SiOzf/SiO2-BN composites.展开更多
After finishing picking the banana, how to tackle banana pesudostem has long been a thorny problem. According to banana pesudostem＇s characteristics of more crassitude stem, high moisture content and heavy fiber dens...After finishing picking the banana, how to tackle banana pesudostem has long been a thorny problem. According to banana pesudostem＇s characteristics of more crassitude stem, high moisture content and heavy fiber density, this paper proposes a efficient, energy-saving and low-loss device for crushing banana pesudostems and returning field.展开更多
The transfer function of the microring resonator is deduced, and the effects of the normalized loss, coupling coefficient and surrounding media on the resonance performance are investigated thoroughly. Utilizing the i...The transfer function of the microring resonator is deduced, and the effects of the normalized loss, coupling coefficient and surrounding media on the resonance performance are investigated thoroughly. Utilizing the improved fused tapering tech- nique and ingenious self-coiling coupling method, a high-quality microring resonator （radius of about 500 I.tm） with larger extinction ratio （〉10 dB） and sharper resonance is designed and fabricated by a segment of continuous sub-micrometer fiber. The microring resonator constructed in this way demonstrates extremely small connection loss with communication fiber in contrast to the planar waveguide technology.展开更多
A special optical fiber is investigated, which has a helical core in the cylindrical cladding. The beam propagation method （BPM） is used for analyzing the impacts of the geometric and physical parameters on the prop...A special optical fiber is investigated, which has a helical core in the cylindrical cladding. The beam propagation method （BPM） is used for analyzing the impacts of the geometric and physical parameters on the properties of mode losses of the helical-core fiber. The propagation loss is 0.32 dB/m for the fundamental mode and the propagation loss is 20.95 dB/m for the LPu mode in the wavelength range of 1050-1065 nm when the core diameter is 19 μm, the pitch of the core＇s helix is 2.66 mm, and the offset of the helix core from the center of the fiber axis is 31 μm. The core diameter of the single-mode helical-core fiber well exceeds that of the conventional large-mode-area fiber. The helical-core fiber can provide the effec- tive large-mode-area single-mode operation without coiling fiber or selecting excitation mode.展开更多
文摘As the cost of quality waste paper continues to escalate in response to an increased global demand for the finite resource, loss of saleable fiber within flotation rejects becomes both environmentally and economically unacceptable. The ability of surfactant spray technology to reduce yield loss without detriment to pulp brightness gains has been demonstrated during both laboratory- and pilot-scale flotation deinking investigations. This paper documents the successful transfer of this technology to a single flotation unit within the deinking line of a mill producing newsprint from 100% secondary fiber. Initial results suggest that the loss of fiber across the unit may be reduced by more than 50% without obvious detriment to final pulp quality.
基金National Natural Science Foundation of China(No.60577034)
文摘The triangular-lattice highly birefringent photonic crystal fibers(PCFs) with gradually increasing diameter of the air holes along radial axis are put forward. The modal birefringence, dispersion and confinement loss of the fundamental mode are simulated by full vector Galerkin finite element method(FEM) with a perfectly matched layer(PML). The results show that this PCF can keep low confinement loss when the rings of air holes are few. When the wavelength is 1.55 μm , the birefringence, the confinement loss of quick-axis and slow-axis are 1.365×10-3, 0.017 dB/m and 0.051 dB/m, respectively. A new way is proposed to fabricate polarization-mainting fibers with high performance.
基金Projects(50902150,90916019) supported by the National Natural Science Foundation of ChinaProject (9140C8203040905) supported by the State Key Laboratory Foundation of ChinaProject(S100103) supported by the Graduate Innovation Foundation of National University of Defense Technology,China
文摘The silica fiber reinforced silica and boron nitride-based composites （SiO2f/SiO2-BN） were prepared firstly via the sol-gel method and then the urea route, and the effects of oxidation treatment on the component, structure, mechanical and dielectric properties of the composites were investigated. The results show that the oxidation treatment at 450 ℃ will not impair the structure of boron nitride, and carbon is the main impurity with the excessive urea. The density of SiO2f/SiO2-BN composites is 1.81 g/cm3, and the flexural strength and elastic modulus are 113.9 MPa and 36.5 GPa, respectively. After oxidation treatment, the density varies to 1.80 g/cm3, and the flexural strength and elastic modulus are decreased to 58.9 MPa and 9.4 GPa, respectively. The mechanical properties of the composites are severely damaged, but they still exhibit a good toughness. The composites show excellent dielectric properties with the dielectric constant and loss tangent being 3.22 and 0.003 9, respectively, which indicates that the oxidation treatment is ineffective to improve the dielectric properties of SiOzf/SiO2-BN composites.
文摘After finishing picking the banana, how to tackle banana pesudostem has long been a thorny problem. According to banana pesudostem＇s characteristics of more crassitude stem, high moisture content and heavy fiber density, this paper proposes a efficient, energy-saving and low-loss device for crushing banana pesudostems and returning field.
基金supported by the National Natural Science Foundation of China(Nos.61007007and11002018)
文摘The transfer function of the microring resonator is deduced, and the effects of the normalized loss, coupling coefficient and surrounding media on the resonance performance are investigated thoroughly. Utilizing the improved fused tapering tech- nique and ingenious self-coiling coupling method, a high-quality microring resonator （radius of about 500 I.tm） with larger extinction ratio （〉10 dB） and sharper resonance is designed and fabricated by a segment of continuous sub-micrometer fiber. The microring resonator constructed in this way demonstrates extremely small connection loss with communication fiber in contrast to the planar waveguide technology.
基金supported by the National Natural Science Foundation of China(Nos.11104043,61107069,60927008)the Natural Science Foundation of Heilongjiang Provincein China(No.LC201006)
文摘A special optical fiber is investigated, which has a helical core in the cylindrical cladding. The beam propagation method （BPM） is used for analyzing the impacts of the geometric and physical parameters on the properties of mode losses of the helical-core fiber. The propagation loss is 0.32 dB/m for the fundamental mode and the propagation loss is 20.95 dB/m for the LPu mode in the wavelength range of 1050-1065 nm when the core diameter is 19 μm, the pitch of the core＇s helix is 2.66 mm, and the offset of the helix core from the center of the fiber axis is 31 μm. The core diameter of the single-mode helical-core fiber well exceeds that of the conventional large-mode-area fiber. The helical-core fiber can provide the effec- tive large-mode-area single-mode operation without coiling fiber or selecting excitation mode.
