By spraying concrete on inner surface,air-supported fabric structures can be used as formwork to construct reinforced concrete shell structures.The fabric formwork has the finished form of concrete structure.Large dev...By spraying concrete on inner surface,air-supported fabric structures can be used as formwork to construct reinforced concrete shell structures.The fabric formwork has the finished form of concrete structure.Large deviation from the desired shape of concrete shells still remains as central problem due to dead weight of concrete and less stiffness of fabric formwork.Polyurethane can be used not only as a bonding layer between fabrics and concrete but also as an additional stiffening layer.However,there is little research on mechanical behaviors of the polyurethane shell structure.This paper presents experimental studies on an inflated fabric model with and without polyurethane,including relief pressure tests,vertical loading tests and horizontal loading tests.Experimental results show that the additional polyurethane layer can significantly enhance the stiffness of the fabric formwork.Compared with the experiment,a numerical model using shell layered finite elements has a good prediction.The reinforcement by polyurethane to improve stiffness of air-supported fabric formwork is expected to be considered in the design and construction of the concrete shell,especially dealing with the advance of shape-control.展开更多
This paper presents a new idea for intensifying protective and stretch recovery properties of micro porous polytetrafluorethylene and hydrophilic polyurethane (PTFE/PU) layered membrane through a co-stretching process...This paper presents a new idea for intensifying protective and stretch recovery properties of micro porous polytetrafluorethylene and hydrophilic polyurethane (PTFE/PU) layered membrane through a co-stretching process. The structure and properties of co-stretching PTFE/PU layered membrane and coated PTFE/PU layered membrane by means of directly coating the PU on the PTFE membrane were investigated using Electron Microscope, Universal Materials Testing Machine, and the water vapor permeability (WVP) was measured according to absorption method of water vapor of GB/T 12704-91. Contrasted to PU coating process, the PU membrane on the co-stretching PTFE/PU membrane is nonporous because of heat treatment process, which can prevent the SARS virus from permeating the Co-stretching PTFE/PU membrane. The stretch and recovery properties of the Co-stretching PTFE/PU membrane is at least 66% after being stretched to 50% of its original length in transverse directions and that of the coated PTFE/PU membrane is 52%. The WVP of the Co-stretching PTFE/PU membrane is 13 523 g/24 h·m^2. The results suggest that when Co-stretching PTFE/PU membrane is laminated to a stretchable fabric, the fabric would have excellent stretch and recovery properties while waterproof and being permeable to water vapor. So, the Co-stretching PTFE/PU membrane laminated fabric will be a comfortable protective clothing material.展开更多
Modern public buildings, such as multiplex cinemas and theaters, along with application of state of the art sound effects bring high acoustic insulation demands. Cinemas are often a part of building complexes such as ...Modern public buildings, such as multiplex cinemas and theaters, along with application of state of the art sound effects bring high acoustic insulation demands. Cinemas are often a part of building complexes such as shopping malls with subjects that produce serious level of noise and vibrations. Apart to regular use of polyurethane in thermal insulation purposes, it is widely used in field of acoustic insulation. Usage of polyurethane foam pads, with specific dynamic characteristics, as a base for structure supports gives a wide range of possibilities in controlling the amount of structural noise and vibrations transferred to the structure. Structure itself and acoustical pads becomes an integral system that behaves together and need to be analyzed as a whole in extensive design. Dynamic characteristics of acoustic pads depend on stress level and in same time they represent elastic supports to the structure and therefore analyzes and design is an iterative process. In other way, introduce of non-conventional material in bearing structure brings some issues, such as transfer of shear forces, that has to be governed by proper structural detailing. There are several possibilities of application in bearing structures, such as above and below steel structure. This paper gives an overall view on polyurethane as material, construction and design principles and example of usage of acoustic pads in steel structure of＂Ster＂ cineplex in Belgrade.展开更多
A series of segmented polyether-polyester polyurethane with amorphous hydrophilic soft segment domains were prepared from 4,4'- diphenylmethane diisocyanate (MDI), polybutylene adipate (Glycol) 2000 (PBA2000), and...A series of segmented polyether-polyester polyurethane with amorphous hydrophilic soft segment domains were prepared from 4,4'- diphenylmethane diisocyanate (MDI), polybutylene adipate (Glycol) 2000 (PBA2000), and polyethylene glycol 1000 (PEG1000), with 1,4-butanediol (BDO) as the chain extender. Furthermore, several representative properties of the polyurethanes, such as moisture permeability, water resistance, hydrophilic property, and phase inversion temperature, were investigated. The studies show that the structure and concentration of soft segment have a remarkable effect on the main application properties of polyurethane. On the contrary, the functional properties of the polyurethane are almost not affected by its hard segment.展开更多
A series of biodegradable aliphatic-aromatic copolyesters, poly(butylene terephthalate-co-butylene adipate-co- ethylene terephthalate-co-ethylene adipate) (PBATE), were synthesized from terephthalic acid (PTA), adipic...A series of biodegradable aliphatic-aromatic copolyesters, poly(butylene terephthalate-co-butylene adipate-co- ethylene terephthalate-co-ethylene adipate) (PBATE), were synthesized from terephthalic acid (PTA), adipic acid (AA), 1,4-butanediol (BG) and ethylene glycol (EG) through direct esterification and polycondensation. The sequence structure and crystallinity of the copolyester were investigated by 1H NMR spectroscopy and the wide-angle X-ray diffractometry (WAXD). The analytical results showed that the PBATE copolyester was a random copolymer and the composition of PBATE copolyester was almost consistent with the feed molar ratios. The crystal structure of PBATE copolyester belonged to the triclinic crystalline system; The variation in melting point of the synthesized PBATE copolyester agreed well with the estimation obtained by the Flory equation and was applicable to the random copolymer.展开更多
In reality, traditional process control system built upon centralized and hierarchical structures presents a weak response to change and is easy to shut down by single failure. Aiming at these problems, a new agent-ba...In reality, traditional process control system built upon centralized and hierarchical structures presents a weak response to change and is easy to shut down by single failure. Aiming at these problems, a new agent-based service-oriented integration architecture was proposed for chemical process automation system. Web services were dynamically orchestrated on the internet and agent behaviors were built in them. Data analysis, model, optimization, control, fault diagnosis and so on were capsuled into different web services. Agents were used for service compositions by negotiation. A prototype system of poly(ethylene terephthalate) process automation was used as the case study to demonstrate the validation of the integration.展开更多
Hybridization of carbon nanotubes （CNT） with graphene provides a promising means of integrating the attributes of both materials, thereby enabling widespread application. Here, we present a method to directly assemb...Hybridization of carbon nanotubes （CNT） with graphene provides a promising means of integrating the attributes of both materials, thereby enabling widespread application. Here, we present a method to directly assemble hybrid CNT- graphene films by a blown bubble method combined with selective substrate annealing. We use polymethylmethacrylate （PMMA） as the polymeric matrix to blow bubbles containing self-assembled multi-walled CNT arrays, and then transform the bubble film into a CNT-graphene hybrid film by thermal annealing on a Cu substrate; PMMA serves as the carbon source for growing single to few-layer graphene among the CNT network until a continuously hybridized structure is formed. Compared to the bare （non-hybridized） CNT networks, the hybrid films exhibit improved electrical conductivity and structural integrity. Our method also enables the fabrication of a multi-walled CNT-Si solar cell, which has high power conversion efficiency, through the assembly of hybrid CNT-graphene structures.展开更多
基金Projects(51178263,51378307)supported by the National Natural Science Foundation of China
文摘By spraying concrete on inner surface,air-supported fabric structures can be used as formwork to construct reinforced concrete shell structures.The fabric formwork has the finished form of concrete structure.Large deviation from the desired shape of concrete shells still remains as central problem due to dead weight of concrete and less stiffness of fabric formwork.Polyurethane can be used not only as a bonding layer between fabrics and concrete but also as an additional stiffening layer.However,there is little research on mechanical behaviors of the polyurethane shell structure.This paper presents experimental studies on an inflated fabric model with and without polyurethane,including relief pressure tests,vertical loading tests and horizontal loading tests.Experimental results show that the additional polyurethane layer can significantly enhance the stiffness of the fabric formwork.Compared with the experiment,a numerical model using shell layered finite elements has a good prediction.The reinforcement by polyurethane to improve stiffness of air-supported fabric formwork is expected to be considered in the design and construction of the concrete shell,especially dealing with the advance of shape-control.
基金Supported by the Ph. D.Innovation Foundation of Donghua University (101 06 0019064)
文摘This paper presents a new idea for intensifying protective and stretch recovery properties of micro porous polytetrafluorethylene and hydrophilic polyurethane (PTFE/PU) layered membrane through a co-stretching process. The structure and properties of co-stretching PTFE/PU layered membrane and coated PTFE/PU layered membrane by means of directly coating the PU on the PTFE membrane were investigated using Electron Microscope, Universal Materials Testing Machine, and the water vapor permeability (WVP) was measured according to absorption method of water vapor of GB/T 12704-91. Contrasted to PU coating process, the PU membrane on the co-stretching PTFE/PU membrane is nonporous because of heat treatment process, which can prevent the SARS virus from permeating the Co-stretching PTFE/PU membrane. The stretch and recovery properties of the Co-stretching PTFE/PU membrane is at least 66% after being stretched to 50% of its original length in transverse directions and that of the coated PTFE/PU membrane is 52%. The WVP of the Co-stretching PTFE/PU membrane is 13 523 g/24 h·m^2. The results suggest that when Co-stretching PTFE/PU membrane is laminated to a stretchable fabric, the fabric would have excellent stretch and recovery properties while waterproof and being permeable to water vapor. So, the Co-stretching PTFE/PU membrane laminated fabric will be a comfortable protective clothing material.
文摘Modern public buildings, such as multiplex cinemas and theaters, along with application of state of the art sound effects bring high acoustic insulation demands. Cinemas are often a part of building complexes such as shopping malls with subjects that produce serious level of noise and vibrations. Apart to regular use of polyurethane in thermal insulation purposes, it is widely used in field of acoustic insulation. Usage of polyurethane foam pads, with specific dynamic characteristics, as a base for structure supports gives a wide range of possibilities in controlling the amount of structural noise and vibrations transferred to the structure. Structure itself and acoustical pads becomes an integral system that behaves together and need to be analyzed as a whole in extensive design. Dynamic characteristics of acoustic pads depend on stress level and in same time they represent elastic supports to the structure and therefore analyzes and design is an iterative process. In other way, introduce of non-conventional material in bearing structure brings some issues, such as transfer of shear forces, that has to be governed by proper structural detailing. There are several possibilities of application in bearing structures, such as above and below steel structure. This paper gives an overall view on polyurethane as material, construction and design principles and example of usage of acoustic pads in steel structure of＂Ster＂ cineplex in Belgrade.
基金Key Foundation of Shannxi Province,China (No.04JK181)China Textile Industry Association(No.2007049)
文摘A series of segmented polyether-polyester polyurethane with amorphous hydrophilic soft segment domains were prepared from 4,4'- diphenylmethane diisocyanate (MDI), polybutylene adipate (Glycol) 2000 (PBA2000), and polyethylene glycol 1000 (PEG1000), with 1,4-butanediol (BDO) as the chain extender. Furthermore, several representative properties of the polyurethanes, such as moisture permeability, water resistance, hydrophilic property, and phase inversion temperature, were investigated. The studies show that the structure and concentration of soft segment have a remarkable effect on the main application properties of polyurethane. On the contrary, the functional properties of the polyurethane are almost not affected by its hard segment.
文摘A series of biodegradable aliphatic-aromatic copolyesters, poly(butylene terephthalate-co-butylene adipate-co- ethylene terephthalate-co-ethylene adipate) (PBATE), were synthesized from terephthalic acid (PTA), adipic acid (AA), 1,4-butanediol (BG) and ethylene glycol (EG) through direct esterification and polycondensation. The sequence structure and crystallinity of the copolyester were investigated by 1H NMR spectroscopy and the wide-angle X-ray diffractometry (WAXD). The analytical results showed that the PBATE copolyester was a random copolymer and the composition of PBATE copolyester was almost consistent with the feed molar ratios. The crystal structure of PBATE copolyester belonged to the triclinic crystalline system; The variation in melting point of the synthesized PBATE copolyester agreed well with the estimation obtained by the Flory equation and was applicable to the random copolymer.
基金Supported by the Major State Basic Research Development Program of China(2012CB720500)the National Natural Science Foundation of China(U1162202,61222303)+2 种基金the Fundamental Research Funds for the Central Universities,Shanghai Municipal Natural Science Foundation(13ZR1411500)Shanghai R&D Platform Construction program(13DZ2295300)Shanghai Leading Academic Discipline Project(B504)
文摘In reality, traditional process control system built upon centralized and hierarchical structures presents a weak response to change and is easy to shut down by single failure. Aiming at these problems, a new agent-based service-oriented integration architecture was proposed for chemical process automation system. Web services were dynamically orchestrated on the internet and agent behaviors were built in them. Data analysis, model, optimization, control, fault diagnosis and so on were capsuled into different web services. Agents were used for service compositions by negotiation. A prototype system of poly(ethylene terephthalate) process automation was used as the case study to demonstrate the validation of the integration.
基金This work was financially supported by the National Nature Science Foundation of China （Nos. 91127004 and 51325202）.
文摘Hybridization of carbon nanotubes （CNT） with graphene provides a promising means of integrating the attributes of both materials, thereby enabling widespread application. Here, we present a method to directly assemble hybrid CNT- graphene films by a blown bubble method combined with selective substrate annealing. We use polymethylmethacrylate （PMMA） as the polymeric matrix to blow bubbles containing self-assembled multi-walled CNT arrays, and then transform the bubble film into a CNT-graphene hybrid film by thermal annealing on a Cu substrate; PMMA serves as the carbon source for growing single to few-layer graphene among the CNT network until a continuously hybridized structure is formed. Compared to the bare （non-hybridized） CNT networks, the hybrid films exhibit improved electrical conductivity and structural integrity. Our method also enables the fabrication of a multi-walled CNT-Si solar cell, which has high power conversion efficiency, through the assembly of hybrid CNT-graphene structures.
