A simple strategy was developed to prepare a tough, self-healing, antibacterial and moldable hydrogel by introducing the natural polyphenolic compound tannic acid(TA) as a cross-linking center for hydrogen bonds. Poly...A simple strategy was developed to prepare a tough, self-healing, antibacterial and moldable hydrogel by introducing the natural polyphenolic compound tannic acid(TA) as a cross-linking center for hydrogen bonds. Polyvinyl alcohol(PVA)-TA hydrogel was prepared by physical mixing using PVA as a main component and TA as a cross-linker. There were two types of physical cross linking bonds in the PVA-TA hydrogel network, which were weaker hydrogen bonds between PVA molecular chains and stronger hydrogen bonds between PVA and TA molecules. The mechanical properties and self-healing ability could be adjusted by changing the contents of PVA and TA. The hydrogel possessed not only high mechanical strength(305 kPa tensile strength and 864 kPa compressive strength), moldability and excellent self-healing properties(95% selfhealing efficiency) but also good antibacterial abilities against S. aureus and E. coli. In addition, after soaking the dried hydrogel in 90 ℃ deionized water for 4 h, they could also regain their self-healing ability to a certain extent. The hydrogels have potential applications in the biomedical fields.展开更多
Moldability evaluation for molded parts, which is the basis of concurrent design, is a key design stage in injection molding design. By moldability evaluation the design problems can be found timely and an optimum pla...Moldability evaluation for molded parts, which is the basis of concurrent design, is a key design stage in injection molding design. By moldability evaluation the design problems can be found timely and an optimum plastic part design achieved. In this paper, a systematic methodology for moldability evaluation based on fuzzy logic is proposed. Firstly, fuzzy set modeling for six key design attributes of molded parts is carried out respectively. Secondly, on the basis of this, the relationship between fuzzy sets for design attributes and fuzzy sets for moldability is established by fuzzy rules that are based on domain experts’ experience and knowledge. At last the integral moldability for molded parts is obtained through fuzzy reasoning. The neural network based fuzzy reasoning approach presented in this paper can improve fuzzy reasoning efficiency greatly, especially for system having a large number of rules and complicated membership functions. An example for moldability evaluation is given to show the feasibility of this proposed methodology.展开更多
To successfully employ powder injection molding (PIM) as a manufacturing technique, the function of the component, design of the part, material and process should be optimized for overall processing ability of the PIM...To successfully employ powder injection molding (PIM) as a manufacturing technique, the function of the component, design of the part, material and process should be optimized for overall processing ability of the PIM process. A comparison between the requirements of flowability and moldability and the compacts shape retention has been made in this work. There is often a contradiction between the requirements of flowability and the compacts shape retention. Many works have been done to attain good molding conditions. However, they fail to take into account the effect of some factors that satisfies good molding conditions on the compacts shape retention during debinding. This paper studies the effect of the powder-binder mixture characteristics and the molding conditions on the flowability and moldability and the shape retention of PIM compacts during debinding process so as to attain the benefits of each.展开更多
Tongji University:Recombination of agricultural residues into moldable composites Increasing efforts have been devoted to developing biobased and biodegrad-able plastics and composites from lig-nocellulosic biomass.Cu...Tongji University:Recombination of agricultural residues into moldable composites Increasing efforts have been devoted to developing biobased and biodegrad-able plastics and composites from lig-nocellulosic biomass.Current bioplastic production entails multiple challenging steps including monomer production from biomass as well as polymer synthesis and modification.Here,the research team led by Professor Lei Zhendong and Wu Deli at Tongji University reports a pr actical recom-bination strategy to transform agricultural residues into moldable cellulose-reinforced lignin(CRL)composites.展开更多
In recent years,electrically conductive hydrogel-based nerve guidance conduits(NGCs)have yielded promising results for treating peripheral nerve injuries(PNIs).However,developed ones are generally pre-manufactured and...In recent years,electrically conductive hydrogel-based nerve guidance conduits(NGCs)have yielded promising results for treating peripheral nerve injuries(PNIs).However,developed ones are generally pre-manufactured and exhibit a limited ability to achieve good contact with nerve tissue with irregu-lar surfaces.Herein,we developed a plasticine-like electrically conductive hydrogel consisting of gelatin,conducting polypyrrole,and tannic acid(named GPT)and assessed its ability to promote peripheral nerve regeneration.The shape-persistent GPT hydrogel exhibited good self-healing properties and could easily be molded to form a conduit that could match any injured nerve tissue.Their electrical properties could be tuned by changing the PPy concentration.In vitro,the improved conductivity of the hydrogel pro-moted dorsal root ganglion(DRG)axonal extension.More importantly,we found that the GPT hydrogel enhanced axonal regeneration and remyelination in vivo,preventing denervation atrophy and enhancing functional recovery in a mice model of sciatic nerve injury.These results suggest that our plasticine-like NGC has huge prospects for clinical application in the repair of PNI.展开更多
Nowadays,there are some problems in the area of distributed operating system(DOS)and its research methods.To solve these problems,we have provided a Distributed Operat-ing System Auto-generating System(DOSAGS)model,wh...Nowadays,there are some problems in the area of distributed operating system(DOS)and its research methods.To solve these problems,we have provided a Distributed Operat-ing System Auto-generating System(DOSAGS)model,which is characterized by intelli-gence,integration and moldability.DOSAGS’ system structure,functions,work principlesand key problems in its implementation are presented.It is obvious that the DOS generatedby DOSAGS is a real new generation distributed OS.展开更多
The aim of this paper is to incorporate cellulose nanocrystals(CNCs) into the polyelectrolyte complex(PEC)matrix to construct polyelectrolyte hydrogels,utilizing carbon dioxide(CO_2)-induction to achieve sol-gel trans...The aim of this paper is to incorporate cellulose nanocrystals(CNCs) into the polyelectrolyte complex(PEC)matrix to construct polyelectrolyte hydrogels,utilizing carbon dioxide(CO_2)-induction to achieve sol-gel transition.The mechanical properties of the hydrogels were tunable with different CNC loadings.The increasing CNCs contributed to significant mechanical reinforcement of the PEC/CNC hydrogels.The study on swelling characteristics of hydrogels manifested the entanglements between CNCs and the polymer chains.The hydrogels also showed good moldability property.A cell counting kit-8(CCK-8)cytotoxicity study showed that the as-prepared composite hydrogels had good biocompatibility to confluent osteoblasts(SD rat) cells.展开更多
In order to investigate the possibility of using different materials as bolus in radiotherapy, five samples denoted by S2 - S6 were prepared and analyzed by comparison with one available commercial bolus denoted by S1...In order to investigate the possibility of using different materials as bolus in radiotherapy, five samples denoted by S2 - S6 were prepared and analyzed by comparison with one available commercial bolus denoted by S1. Sample S1 was a thermoplastic material from Qfix;S2 was a moldable silicon rubber (RTV-530 from Prochima);S3 and S4 were obtained by adding micrometric particles of Al and Cu respectively (at the same mass concentration of 5.5%);S5 was another moldable silicon rubber (GSP400 from Prochima) and S6 was a mixture of GSP400 and micrometric particles of Cu (at the mass concentration of 5.5%). The measurements of normalized transmitted dose as a function of sample thickness were performed for all samples (S1 - S6) at two values of electron beam energy (6 and 9 MeV) produced by a linear accelerator VARIAN 2100SC. The results showed that the maximum of the normalized transmitted dose of manufactured samples (S2 - S6) is registered at smaller sample thicknesses than for the analyzed commercial bolus (sample S1). The smallest sample thickness corresponding to normalized maximum point dose is obtained for sample S2 (RTV-530). Measurements performed for electron beam energy of 6 and 9 MeV have proven the possibility of using the manufactured samples as bolus in radiotherapy.展开更多
The complex interaction between material properties in an induction heating circuit was studied by multi physics simulation and by experimental verification in a full-scale laboratory heater. The work aims to illustra...The complex interaction between material properties in an induction heating circuit was studied by multi physics simulation and by experimental verification in a full-scale laboratory heater. The work aims to illustrate the complexity of the system of interacting materials, but also to propose a method to verify properties of soft magnetic composite materials in an integrated system and to identify which properties are the most critical under different circumstances and load cases. Heat losses at different loads were primarily studied, from DC currents to AC currents at 15, 20 and 25 kHz, respectively. A FE model for magnetic simulation was correlated with a corresponding model for heat simulation. The numerical model, as well as the established input material data, could be verified through the experimental measurements. In this particular study, the current loss in the litz wire was the dominant heat source, thus making the thermal conductivity of the SMC the most important property in this material.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.51773161,51303145,51373130,and 21975057)the Special Project of Technological Innovation of Hubei Province(No.2019ABA115)
文摘A simple strategy was developed to prepare a tough, self-healing, antibacterial and moldable hydrogel by introducing the natural polyphenolic compound tannic acid(TA) as a cross-linking center for hydrogen bonds. Polyvinyl alcohol(PVA)-TA hydrogel was prepared by physical mixing using PVA as a main component and TA as a cross-linker. There were two types of physical cross linking bonds in the PVA-TA hydrogel network, which were weaker hydrogen bonds between PVA molecular chains and stronger hydrogen bonds between PVA and TA molecules. The mechanical properties and self-healing ability could be adjusted by changing the contents of PVA and TA. The hydrogel possessed not only high mechanical strength(305 kPa tensile strength and 864 kPa compressive strength), moldability and excellent self-healing properties(95% selfhealing efficiency) but also good antibacterial abilities against S. aureus and E. coli. In addition, after soaking the dried hydrogel in 90 ℃ deionized water for 4 h, they could also regain their self-healing ability to a certain extent. The hydrogels have potential applications in the biomedical fields.
文摘Moldability evaluation for molded parts, which is the basis of concurrent design, is a key design stage in injection molding design. By moldability evaluation the design problems can be found timely and an optimum plastic part design achieved. In this paper, a systematic methodology for moldability evaluation based on fuzzy logic is proposed. Firstly, fuzzy set modeling for six key design attributes of molded parts is carried out respectively. Secondly, on the basis of this, the relationship between fuzzy sets for design attributes and fuzzy sets for moldability is established by fuzzy rules that are based on domain experts’ experience and knowledge. At last the integral moldability for molded parts is obtained through fuzzy reasoning. The neural network based fuzzy reasoning approach presented in this paper can improve fuzzy reasoning efficiency greatly, especially for system having a large number of rules and complicated membership functions. An example for moldability evaluation is given to show the feasibility of this proposed methodology.
基金This work was supported by the National Natural Science Foundation of Chira(project No.50044012)the Natural Science Foundation of Hunan Provience(project No.99JJYY20048).
文摘To successfully employ powder injection molding (PIM) as a manufacturing technique, the function of the component, design of the part, material and process should be optimized for overall processing ability of the PIM process. A comparison between the requirements of flowability and moldability and the compacts shape retention has been made in this work. There is often a contradiction between the requirements of flowability and the compacts shape retention. Many works have been done to attain good molding conditions. However, they fail to take into account the effect of some factors that satisfies good molding conditions on the compacts shape retention during debinding. This paper studies the effect of the powder-binder mixture characteristics and the molding conditions on the flowability and moldability and the shape retention of PIM compacts during debinding process so as to attain the benefits of each.
文摘Tongji University:Recombination of agricultural residues into moldable composites Increasing efforts have been devoted to developing biobased and biodegrad-able plastics and composites from lig-nocellulosic biomass.Current bioplastic production entails multiple challenging steps including monomer production from biomass as well as polymer synthesis and modification.Here,the research team led by Professor Lei Zhendong and Wu Deli at Tongji University reports a pr actical recom-bination strategy to transform agricultural residues into moldable cellulose-reinforced lignin(CRL)composites.
基金financially supported by the National Natural Science Foundation of China(Nos.51932002 and 51903087)the Science and Technology Innovation Team Project of Foshan(No.2018IT100101)the Joint Fund of Ministry of Education for Equipment Preresearch(No.6141A02022632).
文摘In recent years,electrically conductive hydrogel-based nerve guidance conduits(NGCs)have yielded promising results for treating peripheral nerve injuries(PNIs).However,developed ones are generally pre-manufactured and exhibit a limited ability to achieve good contact with nerve tissue with irregu-lar surfaces.Herein,we developed a plasticine-like electrically conductive hydrogel consisting of gelatin,conducting polypyrrole,and tannic acid(named GPT)and assessed its ability to promote peripheral nerve regeneration.The shape-persistent GPT hydrogel exhibited good self-healing properties and could easily be molded to form a conduit that could match any injured nerve tissue.Their electrical properties could be tuned by changing the PPy concentration.In vitro,the improved conductivity of the hydrogel pro-moted dorsal root ganglion(DRG)axonal extension.More importantly,we found that the GPT hydrogel enhanced axonal regeneration and remyelination in vivo,preventing denervation atrophy and enhancing functional recovery in a mice model of sciatic nerve injury.These results suggest that our plasticine-like NGC has huge prospects for clinical application in the repair of PNI.
基金Software-Engineering National Key Laboratory of Wuhan University.
文摘Nowadays,there are some problems in the area of distributed operating system(DOS)and its research methods.To solve these problems,we have provided a Distributed Operat-ing System Auto-generating System(DOSAGS)model,which is characterized by intelli-gence,integration and moldability.DOSAGS’ system structure,functions,work principlesand key problems in its implementation are presented.It is obvious that the DOS generatedby DOSAGS is a real new generation distributed OS.
基金National Natural Science Foundation of China(No.51403035)
文摘The aim of this paper is to incorporate cellulose nanocrystals(CNCs) into the polyelectrolyte complex(PEC)matrix to construct polyelectrolyte hydrogels,utilizing carbon dioxide(CO_2)-induction to achieve sol-gel transition.The mechanical properties of the hydrogels were tunable with different CNC loadings.The increasing CNCs contributed to significant mechanical reinforcement of the PEC/CNC hydrogels.The study on swelling characteristics of hydrogels manifested the entanglements between CNCs and the polymer chains.The hydrogels also showed good moldability property.A cell counting kit-8(CCK-8)cytotoxicity study showed that the as-prepared composite hydrogels had good biocompatibility to confluent osteoblasts(SD rat) cells.
文摘In order to investigate the possibility of using different materials as bolus in radiotherapy, five samples denoted by S2 - S6 were prepared and analyzed by comparison with one available commercial bolus denoted by S1. Sample S1 was a thermoplastic material from Qfix;S2 was a moldable silicon rubber (RTV-530 from Prochima);S3 and S4 were obtained by adding micrometric particles of Al and Cu respectively (at the same mass concentration of 5.5%);S5 was another moldable silicon rubber (GSP400 from Prochima) and S6 was a mixture of GSP400 and micrometric particles of Cu (at the mass concentration of 5.5%). The measurements of normalized transmitted dose as a function of sample thickness were performed for all samples (S1 - S6) at two values of electron beam energy (6 and 9 MeV) produced by a linear accelerator VARIAN 2100SC. The results showed that the maximum of the normalized transmitted dose of manufactured samples (S2 - S6) is registered at smaller sample thicknesses than for the analyzed commercial bolus (sample S1). The smallest sample thickness corresponding to normalized maximum point dose is obtained for sample S2 (RTV-530). Measurements performed for electron beam energy of 6 and 9 MeV have proven the possibility of using the manufactured samples as bolus in radiotherapy.
文摘The complex interaction between material properties in an induction heating circuit was studied by multi physics simulation and by experimental verification in a full-scale laboratory heater. The work aims to illustrate the complexity of the system of interacting materials, but also to propose a method to verify properties of soft magnetic composite materials in an integrated system and to identify which properties are the most critical under different circumstances and load cases. Heat losses at different loads were primarily studied, from DC currents to AC currents at 15, 20 and 25 kHz, respectively. A FE model for magnetic simulation was correlated with a corresponding model for heat simulation. The numerical model, as well as the established input material data, could be verified through the experimental measurements. In this particular study, the current loss in the litz wire was the dominant heat source, thus making the thermal conductivity of the SMC the most important property in this material.
