This paper addresses some key issues in supporting product family design in a 3 D CAD/ PDM integrated system and introduces the techniques developed or adopted in building the integrated system. The general architectu...This paper addresses some key issues in supporting product family design in a 3 D CAD/ PDM integrated system and introduces the techniques developed or adopted in building the integrated system. The general architecture of a 3D CAD/PDM integrated system is organized as five tiers. Multi-agent technology is applied with a collaborative design environment. The rule-based product family architecture ( PFA ) and tabular layouts of article characteristics (TLAC) technique are applied to represent the knowledge for product families. They make the knowledge understandable, simplified and can be exchanged among heterogeneous information systems. A transparently concentric integrated mode is put forward to enable the heterogeneous processes to interact and communicate regardless of the language used to construct each process. With the mode, function calling and information exchanging among different processes are carried out via message translation/parse approach. Currently, the integrated system is implemented in the platform of Windows NT and 2000.展开更多
Building integrated concentrating photovoltaic(BICPV)windows have attracted numerous studies in recent years.However,there is a tradeoff between the light transmittance and power generation efficiency in the design of...Building integrated concentrating photovoltaic(BICPV)windows have attracted numerous studies in recent years.However,there is a tradeoff between the light transmittance and power generation efficiency in the design of BICPV window.In this paper,a smart luminescent solar concentrator(LSC)is introduced as the BICPV window.The proposed smart LSC system features on the combination of fluorescent dyes with thermochromic materials to enhance photoelectric conversion efficiency as well as form a dynamic response mechanism to ambient solar radiation and environmental temperature.In this study,a BICPV smart window system consists of the waveguide doped with organic dye Lumogen F Red-305(BASF)and the thermochromic hydrogel membrane has been developed.The research on analytic design parameters is executed through optical simulation by ray tracing technology along with outdoor comparative experiments.From simulations for a smart LSC of 100 mm×100 mm×3 mm with a bottom-mounted solar cell of 100 mm×10 mm,the optical effective concentration is found to be with the range of 1.23 to 1.31 when a highest gain of 1.26 in power over the bare solar cell is obtained from experiments.展开更多
When concentrated forces are applied at any points of the outer region of an ellipse in an infinite plate, the complex potentials are determined using the conformal mapping method and Cauchy's integral formula. And t...When concentrated forces are applied at any points of the outer region of an ellipse in an infinite plate, the complex potentials are determined using the conformal mapping method and Cauchy's integral formula. And then, based on the superposition principle, the analyt- ical solutions for stress around an elliptical hole in an infinite plate subjected to a uniform far-field stress and concentrated forces, are obtained. Tangential stress concentration will occur on the hole boundary when only far-field uniform loads are applied. When concen- trated forces are applied in the reversed directions of the uniform loads, tangential stress concentration on the hole boundary can be released significantly. In order to minimize the tangential stress concentration, we need to determine the optimum positions and values of the concentrated forces. Three different optimization methods are applied to achieve this aim. The results show that the tangential stress can be released significantly when the op- timized concentrated forces are applied.展开更多
Indoor airborne bioaerosols of outdoor origin play an important role in determining the exposure of humans to bioaerosols because people spend most of their time indoors. However, there are few studies focusing on ind...Indoor airborne bioaerosols of outdoor origin play an important role in determining the exposure of humans to bioaerosols because people spend most of their time indoors. However, there are few studies focusing on indoor bioaerosols originating from outdoors. In this study, indoor versus outdoor size-resolved concentrations and particle asymmetry factors of airborne fluorescent bioaerosols in an office room were measured continuously for 6 days (144 h) using a fluorescent bioaerosol detector. The windows and door of this room were closed to ensure that there was only air infiltration; moreover, any human activities were ceased during sampling to inhibit effects of indoor sources. We focused on fine particles, since few coarse particles enter indoor environments, when windows and doors are closed. Both indoor and outdoor fluorescent bioaerosol size distributions were fit with two-mode lognormal distributions (indoor R2 = 0.935, outdoor R2 = 0.938). Asymmetry factor distributions were also fit with lognormal distributions (indoor R2 = 0.992, outdoor R2 = 0.992). Correlations between indoor and outdoor fluorescent bioaerosol concentrations show significant concentration-attenuation and a time lag during the study period. A two-parameter, semi-empirical model was used to predict concentrations of indoor fluorescent bioaerosols of outdoor origin. The measured and predicted concentrations had a linear relationship for the studied size fractions, with an R2 for all size fractions of larger than 0.83.展开更多
A dispersion model for the estimation of crosswind integrated concentrations in the surface-based inversion is proposed.The generalized forms of eddy diffusivity with spatial dependence in both horizontal and vertical...A dispersion model for the estimation of crosswind integrated concentrations in the surface-based inversion is proposed.The generalized forms of eddy diffusivity with spatial dependence in both horizontal and vertical directions and vertical height-dependent wind speed are considered.In view of the computational limitation associated with numerical models for Dirac-delta function,the source term is expressed as a limiting case of normal distribution.The accuracy of the employed numerical scheme to solve the resulting partial differential equation with appropriate physically relevant boundary conditions is checked with those obtained from the respective analytical solutions available in literature for the particular forms of eddy diffusivity and wind speed.Concentrations computed from the proposed model are found close to those obtained from analytical models.The concentrations obtained from the proposed model are evaluated for the generalized functional forms of eddy diffusivity(Degrazia and Moraes,1992;Degrazia et al.,2001)and diabatic logarithmic profile as well as power-law profile of wind speed with the observations from Hanford(Doran et al.,1984)and Copenhagen(Gryning and Lyck,1984)diffusion experiments in stable and unstable conditions,respectively.Majority of the cases i.e.,64%and 96%are predicted in factor of two to observations in both stable and unstable conditions,respectively.展开更多
基金This paper is supported by National High-Tech Research and Development Plan Foundation in China(2005AA4Z3060) and Electronic Development Fund in 2003.
文摘This paper addresses some key issues in supporting product family design in a 3 D CAD/ PDM integrated system and introduces the techniques developed or adopted in building the integrated system. The general architecture of a 3D CAD/PDM integrated system is organized as five tiers. Multi-agent technology is applied with a collaborative design environment. The rule-based product family architecture ( PFA ) and tabular layouts of article characteristics (TLAC) technique are applied to represent the knowledge for product families. They make the knowledge understandable, simplified and can be exchanged among heterogeneous information systems. A transparently concentric integrated mode is put forward to enable the heterogeneous processes to interact and communicate regardless of the language used to construct each process. With the mode, function calling and information exchanging among different processes are carried out via message translation/parse approach. Currently, the integrated system is implemented in the platform of Windows NT and 2000.
基金supported by the grants from the Key Research and Development Program of Anhui Province,China(No.S202004a07020038)the National Natural Science Foundation of China(No.51908174)Anhui Provincial Natural Science Foundation,China(No.1908085QE206).
文摘Building integrated concentrating photovoltaic(BICPV)windows have attracted numerous studies in recent years.However,there is a tradeoff between the light transmittance and power generation efficiency in the design of BICPV window.In this paper,a smart luminescent solar concentrator(LSC)is introduced as the BICPV window.The proposed smart LSC system features on the combination of fluorescent dyes with thermochromic materials to enhance photoelectric conversion efficiency as well as form a dynamic response mechanism to ambient solar radiation and environmental temperature.In this study,a BICPV smart window system consists of the waveguide doped with organic dye Lumogen F Red-305(BASF)and the thermochromic hydrogel membrane has been developed.The research on analytic design parameters is executed through optical simulation by ray tracing technology along with outdoor comparative experiments.From simulations for a smart LSC of 100 mm×100 mm×3 mm with a bottom-mounted solar cell of 100 mm×10 mm,the optical effective concentration is found to be with the range of 1.23 to 1.31 when a highest gain of 1.26 in power over the bare solar cell is obtained from experiments.
基金supported by the National Natural Science Foundation of China [grant numbers 11172101, 11572126]
文摘When concentrated forces are applied at any points of the outer region of an ellipse in an infinite plate, the complex potentials are determined using the conformal mapping method and Cauchy's integral formula. And then, based on the superposition principle, the analyt- ical solutions for stress around an elliptical hole in an infinite plate subjected to a uniform far-field stress and concentrated forces, are obtained. Tangential stress concentration will occur on the hole boundary when only far-field uniform loads are applied. When concen- trated forces are applied in the reversed directions of the uniform loads, tangential stress concentration on the hole boundary can be released significantly. In order to minimize the tangential stress concentration, we need to determine the optimum positions and values of the concentrated forces. Three different optimization methods are applied to achieve this aim. The results show that the tangential stress can be released significantly when the op- timized concentrated forces are applied.
基金This work was supported by the National Key Research and Development Plan from the Ministry of Science and Technology of China through Grant No. 2016YFC0700500, as well as funding from Innovative Research Groups of the National Natural Science Foundation of China (No. 51521005), and the National Natural Science Foundation of China (No. 51678328 & 21221004 & 41227805 & 21190054).
文摘Indoor airborne bioaerosols of outdoor origin play an important role in determining the exposure of humans to bioaerosols because people spend most of their time indoors. However, there are few studies focusing on indoor bioaerosols originating from outdoors. In this study, indoor versus outdoor size-resolved concentrations and particle asymmetry factors of airborne fluorescent bioaerosols in an office room were measured continuously for 6 days (144 h) using a fluorescent bioaerosol detector. The windows and door of this room were closed to ensure that there was only air infiltration; moreover, any human activities were ceased during sampling to inhibit effects of indoor sources. We focused on fine particles, since few coarse particles enter indoor environments, when windows and doors are closed. Both indoor and outdoor fluorescent bioaerosol size distributions were fit with two-mode lognormal distributions (indoor R2 = 0.935, outdoor R2 = 0.938). Asymmetry factor distributions were also fit with lognormal distributions (indoor R2 = 0.992, outdoor R2 = 0.992). Correlations between indoor and outdoor fluorescent bioaerosol concentrations show significant concentration-attenuation and a time lag during the study period. A two-parameter, semi-empirical model was used to predict concentrations of indoor fluorescent bioaerosols of outdoor origin. The measured and predicted concentrations had a linear relationship for the studied size fractions, with an R2 for all size fractions of larger than 0.83.
文摘A dispersion model for the estimation of crosswind integrated concentrations in the surface-based inversion is proposed.The generalized forms of eddy diffusivity with spatial dependence in both horizontal and vertical directions and vertical height-dependent wind speed are considered.In view of the computational limitation associated with numerical models for Dirac-delta function,the source term is expressed as a limiting case of normal distribution.The accuracy of the employed numerical scheme to solve the resulting partial differential equation with appropriate physically relevant boundary conditions is checked with those obtained from the respective analytical solutions available in literature for the particular forms of eddy diffusivity and wind speed.Concentrations computed from the proposed model are found close to those obtained from analytical models.The concentrations obtained from the proposed model are evaluated for the generalized functional forms of eddy diffusivity(Degrazia and Moraes,1992;Degrazia et al.,2001)and diabatic logarithmic profile as well as power-law profile of wind speed with the observations from Hanford(Doran et al.,1984)and Copenhagen(Gryning and Lyck,1984)diffusion experiments in stable and unstable conditions,respectively.Majority of the cases i.e.,64%and 96%are predicted in factor of two to observations in both stable and unstable conditions,respectively.