A new way to solve the scheduling problem ofgarment assembly line based on genetic algorithmwas proposed. The chromosome was decoded usingtask precedence relation and after the operation ofreproduction, crossover and ...A new way to solve the scheduling problem ofgarment assembly line based on genetic algorithmwas proposed. The chromosome was decoded usingtask precedence relation and after the operation ofreproduction, crossover and mutation, the globaloptimal result can be obtained. Fitness function wasrepresented by smoothness Index ( SI ). Thesimulation shows that the method proposed in thispaper is better than the conventional way and theoptimized solution can be got in this way.展开更多
Single-walled carbon nanotubes （SWCNTs） with specific diameters are required for various applications particularly in electronics and photonics, since the diameter is an essential characteristic determining their el...Single-walled carbon nanotubes （SWCNTs） with specific diameters are required for various applications particularly in electronics and photonics, since the diameter is an essential characteristic determining their electronic and optical properties. In this work, the selective growth of SWCNTs with a certain mean diameter is achieved by the addition of appropriate amounts of CO2 mixed with the carbon source （CO） into the aerosol （floating catalyst） chemical vapor deposition reactor. The noticeable shift of the peaks in the absorption spectra reveals that the mean diameters of the as-deposited SWCNTs are efficiently altered from 1.2 to 1.9 nm with increasing CO2 concentration. It is believed that CO2 acts as an etching agent and can selectively etch small diameter tubes due to their highly curved carbon surfaces. Polymer-free as-deposited SWCNT films with the desired diameters are used as saturable absorbers after stamping onto a highly reflecting Ag-mirror using a simple dry-transfer technique. Sub-picosecond mode-locked fiber laser operations at -1.56μm and -2 μm are demonstrated, showing improvements in the performance after the optimization of the SWCNT properties.展开更多
Boundary-layer wind tunnel provides a unique platform to reproduce urban, suburban and rural atmospheric boundary layer （ABL） by using roughness devices such as vortex generators, floor roughness, barrier wails, and...Boundary-layer wind tunnel provides a unique platform to reproduce urban, suburban and rural atmospheric boundary layer （ABL） by using roughness devices such as vortex generators, floor roughness, barrier wails, and slots in the extended test-section floor in the contraction cone. Each passive device impacts wind properties in a certain way. In this study, influence of various passive devices on wind properties has been investigated. Experi- ments using eighteen different configurations of the passive devices have been carried out to simulate urban, sub-urban, and rural climate conditions in a boundary-layer wind tunnel. The effect of each configuration on the wind characteristics is presented. It was found that higher barrier height and more number of roughness elements on the floor, generated higher turbulence and therefore higher model scale factors were obtained. However, in- creased slot width in the extended test-section floor in the contraction cone of the wind tunnel seemed to have a little effect on wind characteristics.展开更多
We report on InGaAs quantum disks （QDks） controllably formed on the top （001） facet of nano-patterned GaAs pyramidal platforms. The QDks exhibit pyramidal shape with special facets and varied dimensions, depending...We report on InGaAs quantum disks （QDks） controllably formed on the top （001） facet of nano-patterned GaAs pyramidal platforms. The QDks exhibit pyramidal shape with special facets and varied dimensions, depending on the GaAs pyramidal buffer and the amount of InGaAs deposited. The formation of QDks is explained by the overgrowth of an InGaAs layer and thereafter coalescence of small InGaAs islands. Photoluminescence （PL） characteristics of ensemble QDks and exciton features of individual QDks together demonstrate that we may achieve a transition from zero-dimensional （0D） to two-dimensional （2D） quantum structure with increasing QDk size. This transition provides the flexibility to continuously tailor the dimensionality and subsequently the quantum confinement of semiconductor nanostructures via site-controlled self-assembled epitaxy for device applications based on single quantum structures.展开更多
There is a simple explanation why Shanghai, once synonymous with custom tailoring, now has far fewer tailors than Hong Kong： the Mao suit （or the Sun Yat-sen suit, as it＇s known in China）.
基金Financed by Henan provincial Fund (No. 0324300201)
文摘A new way to solve the scheduling problem ofgarment assembly line based on genetic algorithmwas proposed. The chromosome was decoded usingtask precedence relation and after the operation ofreproduction, crossover and mutation, the globaloptimal result can be obtained. Fitness function wasrepresented by smoothness Index ( SI ). Thesimulation shows that the method proposed in thispaper is better than the conventional way and theoptimized solution can be got in this way.
文摘Single-walled carbon nanotubes （SWCNTs） with specific diameters are required for various applications particularly in electronics and photonics, since the diameter is an essential characteristic determining their electronic and optical properties. In this work, the selective growth of SWCNTs with a certain mean diameter is achieved by the addition of appropriate amounts of CO2 mixed with the carbon source （CO） into the aerosol （floating catalyst） chemical vapor deposition reactor. The noticeable shift of the peaks in the absorption spectra reveals that the mean diameters of the as-deposited SWCNTs are efficiently altered from 1.2 to 1.9 nm with increasing CO2 concentration. It is believed that CO2 acts as an etching agent and can selectively etch small diameter tubes due to their highly curved carbon surfaces. Polymer-free as-deposited SWCNT films with the desired diameters are used as saturable absorbers after stamping onto a highly reflecting Ag-mirror using a simple dry-transfer technique. Sub-picosecond mode-locked fiber laser operations at -1.56μm and -2 μm are demonstrated, showing improvements in the performance after the optimization of the SWCNT properties.
文摘Boundary-layer wind tunnel provides a unique platform to reproduce urban, suburban and rural atmospheric boundary layer （ABL） by using roughness devices such as vortex generators, floor roughness, barrier wails, and slots in the extended test-section floor in the contraction cone. Each passive device impacts wind properties in a certain way. In this study, influence of various passive devices on wind properties has been investigated. Experi- ments using eighteen different configurations of the passive devices have been carried out to simulate urban, sub-urban, and rural climate conditions in a boundary-layer wind tunnel. The effect of each configuration on the wind characteristics is presented. It was found that higher barrier height and more number of roughness elements on the floor, generated higher turbulence and therefore higher model scale factors were obtained. However, in- creased slot width in the extended test-section floor in the contraction cone of the wind tunnel seemed to have a little effect on wind characteristics.
文摘We report on InGaAs quantum disks （QDks） controllably formed on the top （001） facet of nano-patterned GaAs pyramidal platforms. The QDks exhibit pyramidal shape with special facets and varied dimensions, depending on the GaAs pyramidal buffer and the amount of InGaAs deposited. The formation of QDks is explained by the overgrowth of an InGaAs layer and thereafter coalescence of small InGaAs islands. Photoluminescence （PL） characteristics of ensemble QDks and exciton features of individual QDks together demonstrate that we may achieve a transition from zero-dimensional （0D） to two-dimensional （2D） quantum structure with increasing QDk size. This transition provides the flexibility to continuously tailor the dimensionality and subsequently the quantum confinement of semiconductor nanostructures via site-controlled self-assembled epitaxy for device applications based on single quantum structures.
文摘There is a simple explanation why Shanghai, once synonymous with custom tailoring, now has far fewer tailors than Hong Kong： the Mao suit （or the Sun Yat-sen suit, as it＇s known in China）.
