In the context of banning gated communities, blocks returning to the human-oriented scale become the new normal, and pedestrian system design will be paid more attention in the urban planning field. Oct-Loft Creative ...In the context of banning gated communities, blocks returning to the human-oriented scale become the new normal, and pedestrian system design will be paid more attention in the urban planning field. Oct-Loft Creative Park is a template for open blocks in Shenzhen, with a convenient and humanized pedestrian system. This paper selects the creative park's pedestrian system as the research object, using the environment-behavior theory for analysis. Finally, optimization strategies of pedestrian system will be put forward.展开更多
Better dealing with carbon issues can support the management of current greenhouse gas emissions while achieving energy economic diversification and energy security. Carbon dioxide displacement has become the most ack...Better dealing with carbon issues can support the management of current greenhouse gas emissions while achieving energy economic diversification and energy security. Carbon dioxide displacement has become the most acknowledged and practical method in enhanced oil recovery system. This is because of its oil sweep efficiency and ability to reduce the level of greenhouse gas emission. Nevertheless, it would lead to the organic solid phase deposition, which causes the changes of the wettability and the damages of wellbores and reservoirs. In this study, we used slim tube test and component test to research the dynamic characteristics of displacement process. In addition, the mechanism of porous media blockage was also investigated. Results show that when the displacement pressure closed to the minimum miscibility pressure, reservoir blockage in pore throat could happen. Component test characterizes that during near miscible displacement process, the components of oil sample varied obviously, the variation range of peak component carbon marks fluctuated strongly. Crude oil component differentiation could happen after carbon dioxide fully contacted with oil. Besides, the rapid extraction mechanism of aromatic hydrocarbons played a significant role in this process under such condition. The reason is that the solubility of saturated hydrocarbons to asphaltene and non-hydrocarbons is obviously weaker than aromatic hydrocarbons. Controlling the pressure is considered as an important link to prevent the occurrence of blocking in the carbon dioxide multiphase and multicomponent displacement process.展开更多
Liquid crystalline multi-block copolymers poly[1,6-bis(4-oxybenzoyl-oxy)hexane terephthalate]-b-bisphenol A polycarbonate (PHTH-6-b-PC) with different segments of polycarbonate (PC) and thermotropic polyester PHTH-6 w...Liquid crystalline multi-block copolymers poly[1,6-bis(4-oxybenzoyl-oxy)hexane terephthalate]-b-bisphenol A polycarbonate (PHTH-6-b-PC) with different segments of polycarbonate (PC) and thermotropic polyester PHTH-6 were synthesized in tetrachloroethane at 144 similar to 146 degrees C. The influence of segment length on the resulting phase structure and thermal behavior of block copolymers was also discussed. It is demonstrated by TEM and DMA that the resulting block copolymers show a considerable microphase separation. The degree of phase separation and the thermal behavior of the block copolymers are strongly dependent on the molecular weight of the segments incorporated.展开更多
The effect of crystallization conditions of poly(butylene succinate)(PBS) component on the crystallization of poly(tetramethylene oxide)(PTMO) component in their segment block copolymer, with a higher PTMO content(PTM...The effect of crystallization conditions of poly(butylene succinate)(PBS) component on the crystallization of poly(tetramethylene oxide)(PTMO) component in their segment block copolymer, with a higher PTMO content(PTMO mass fraction is 67%), was investigated by DSC and temperature-dependent FTIR. It is found that the isothermal crystallization time(tIC) of PBS has an effect on the crystallization behavior of PTMO component. Perturbation correlation move-window two-dimensional(PCMW2 D) correlation analysis and generalized 2 D correlation analysis(2 DIR) were performed to explore the origin of this phenomenon. The PCMW2 D and 2 DIR results show that the correlation intensity peak observed at around 20 ℃ for PTMO is due to the PTMO chains movements forced by the PBS chains folded movements. If tIC of PBS at temperature of 20 ℃ is prolonged, more PTMO components are incorporated in the region between PBS lamellae and the peak at-7.6 ℃(belonging to less-constricted PTMO chains) changes smaller and even disappears, while the peak at-16.3 ℃ belonging to more-constricted PTMO chains gets bigger. A crystallization model was also established in this study. The results of tensile testing showed that tensile strength slightly increased and elongation at break decreased with increasing heat treatment time at 40 ℃.展开更多
Block copolymer lithography is emerging as one of the leading technologies for patteming nanoscale dense features. In almost all potential applications of this technology, control over the orientation of cylindrical a...Block copolymer lithography is emerging as one of the leading technologies for patteming nanoscale dense features. In almost all potential applications of this technology, control over the orientation of cylindrical and lamellar domains is required for pattern transfer from the block copolymer film. This review highlights the state-of-art development of brushes to modify the substrates to control the assembly behaviors of block copolymers in films. Selected important contributions to the development of self-assembled monolayers, polymer brushes and mats, and chemically patterned brushes are discussed.展开更多
The ABA block copolymers of polyethylene glycol(PEG) as B block and poly N isopropylacrylamide(PNIPA) as A block were synthesized by means of radical polymerization with one step. The block polymers exhibit ther...The ABA block copolymers of polyethylene glycol(PEG) as B block and poly N isopropylacrylamide(PNIPA) as A block were synthesized by means of radical polymerization with one step. The block polymers exhibit thermosensitive behavior at a higher LCST temperature than homopolymer of NIPA.展开更多
文摘In the context of banning gated communities, blocks returning to the human-oriented scale become the new normal, and pedestrian system design will be paid more attention in the urban planning field. Oct-Loft Creative Park is a template for open blocks in Shenzhen, with a convenient and humanized pedestrian system. This paper selects the creative park's pedestrian system as the research object, using the environment-behavior theory for analysis. Finally, optimization strategies of pedestrian system will be put forward.
文摘Better dealing with carbon issues can support the management of current greenhouse gas emissions while achieving energy economic diversification and energy security. Carbon dioxide displacement has become the most acknowledged and practical method in enhanced oil recovery system. This is because of its oil sweep efficiency and ability to reduce the level of greenhouse gas emission. Nevertheless, it would lead to the organic solid phase deposition, which causes the changes of the wettability and the damages of wellbores and reservoirs. In this study, we used slim tube test and component test to research the dynamic characteristics of displacement process. In addition, the mechanism of porous media blockage was also investigated. Results show that when the displacement pressure closed to the minimum miscibility pressure, reservoir blockage in pore throat could happen. Component test characterizes that during near miscible displacement process, the components of oil sample varied obviously, the variation range of peak component carbon marks fluctuated strongly. Crude oil component differentiation could happen after carbon dioxide fully contacted with oil. Besides, the rapid extraction mechanism of aromatic hydrocarbons played a significant role in this process under such condition. The reason is that the solubility of saturated hydrocarbons to asphaltene and non-hydrocarbons is obviously weaker than aromatic hydrocarbons. Controlling the pressure is considered as an important link to prevent the occurrence of blocking in the carbon dioxide multiphase and multicomponent displacement process.
文摘Liquid crystalline multi-block copolymers poly[1,6-bis(4-oxybenzoyl-oxy)hexane terephthalate]-b-bisphenol A polycarbonate (PHTH-6-b-PC) with different segments of polycarbonate (PC) and thermotropic polyester PHTH-6 were synthesized in tetrachloroethane at 144 similar to 146 degrees C. The influence of segment length on the resulting phase structure and thermal behavior of block copolymers was also discussed. It is demonstrated by TEM and DMA that the resulting block copolymers show a considerable microphase separation. The degree of phase separation and the thermal behavior of the block copolymers are strongly dependent on the molecular weight of the segments incorporated.
基金Funded by the Science and Technology Program of Sichuan,China(No.2016FZ0033)the Science and Technology Program of Sichuan Luzhou,China(No.2016-S-63(1/3)
文摘The effect of crystallization conditions of poly(butylene succinate)(PBS) component on the crystallization of poly(tetramethylene oxide)(PTMO) component in their segment block copolymer, with a higher PTMO content(PTMO mass fraction is 67%), was investigated by DSC and temperature-dependent FTIR. It is found that the isothermal crystallization time(tIC) of PBS has an effect on the crystallization behavior of PTMO component. Perturbation correlation move-window two-dimensional(PCMW2 D) correlation analysis and generalized 2 D correlation analysis(2 DIR) were performed to explore the origin of this phenomenon. The PCMW2 D and 2 DIR results show that the correlation intensity peak observed at around 20 ℃ for PTMO is due to the PTMO chains movements forced by the PBS chains folded movements. If tIC of PBS at temperature of 20 ℃ is prolonged, more PTMO components are incorporated in the region between PBS lamellae and the peak at-7.6 ℃(belonging to less-constricted PTMO chains) changes smaller and even disappears, while the peak at-16.3 ℃ belonging to more-constricted PTMO chains gets bigger. A crystallization model was also established in this study. The results of tensile testing showed that tensile strength slightly increased and elongation at break decreased with increasing heat treatment time at 40 ℃.
基金financially supported by the National Natural Science Foundation of China(Nos.51173181 and 51373166)“The Hundred Talents Program”from the Chinese Academy of Sciences and the International S&T Cooperation Program from Department of Science and Technology of Jilin Province(No.20160414032GH)
文摘Block copolymer lithography is emerging as one of the leading technologies for patteming nanoscale dense features. In almost all potential applications of this technology, control over the orientation of cylindrical and lamellar domains is required for pattern transfer from the block copolymer film. This review highlights the state-of-art development of brushes to modify the substrates to control the assembly behaviors of block copolymers in films. Selected important contributions to the development of self-assembled monolayers, polymer brushes and mats, and chemically patterned brushes are discussed.
文摘The ABA block copolymers of polyethylene glycol(PEG) as B block and poly N isopropylacrylamide(PNIPA) as A block were synthesized by means of radical polymerization with one step. The block polymers exhibit thermosensitive behavior at a higher LCST temperature than homopolymer of NIPA.
