The local and global mechanical responses of gas tungsten arc welds（GTAW） of a 2219-T87 aluminum alloy were investigated with experiment and numerical simulation.Digital image correlation（DIC） was used to access t...The local and global mechanical responses of gas tungsten arc welds（GTAW） of a 2219-T87 aluminum alloy were investigated with experiment and numerical simulation.Digital image correlation（DIC） was used to access the local strain fields in transversely loaded welds and to determine the local stress-strain curves of various regions in the joint.The results show that the DIC method is efficient to acquire the local stress-strain curves but the curves of harder regions are incomplete because the stress and strain ranges are limited by the weakest region.With appropriate extrapolation,the complete local stress-strain curves were acquired and proved to be effective to predict the tensile behavior of the welded joint.During the tensile process,the fracture initiates from the weld toes owing to their plastic strain concentrations and then propagates along the fusion line,finally propagates into the partially melted zone（PMZ）.展开更多
The hot deformation behavior of Ti-3.0Al-3.7Cr-2.0Fe-0.1B (TACFB) titanium alloy was investigated using a Gleeble-1500D thermal simulator in the temperature range of 800-950 °C, at constant strain rate from 0.01 ...The hot deformation behavior of Ti-3.0Al-3.7Cr-2.0Fe-0.1B (TACFB) titanium alloy was investigated using a Gleeble-1500D thermal simulator in the temperature range of 800-950 °C, at constant strain rate from 0.01 s-1 to 10 s-1 and with height reduction of 70%. Flow stress and microstructure evolution during hot compression of TACFB alloy were investigated. The processing map of TACFB alloy was obtained. The results indicate that the hot deformation behavior of TACFB alloy is sensitive to the deformation temperature and strain rate. The peak flow stress decreases with increasing the test temperature and decreasing the strain rate. The constitutive relationship of TACFB alloy was obtained on the base of Arrhenius equations. When the strain rates are higher than 1.0 s-1, the dynamic recrystallization occurs, and the higher the strain rates are, the more the recrystallization is.展开更多
Electronic Commerce or E-Commerce is the concept of making trade in electronic environment which has emerged by the use of the internet in commerce and increased after 1995. Organizations started to use electronic com...Electronic Commerce or E-Commerce is the concept of making trade in electronic environment which has emerged by the use of the internet in commerce and increased after 1995. Organizations started to use electronic commerce by internet facilities nearby their traditional marketing methods to increase their sales and profits. E-Commerce has many advantages when compared to traditional trade. This paper aims to take out these advantages for the companies which want to make use of electronic commerce and includes important advices for these companies. The paper also includes the basic version of an e-commerce business, by analysing one of the most successful firms in Turkey, yemeksepeti.com in terms of an Entity-Relationship Diagram （ERD） and Event Driven Process （EDP） to explain the organizations how an e-commerce business model should be constructed systematically. An ERD is a data modeling technique which graphically illustrates an information system＇s entities and the relationships between those entities. On the other hand, EDP is a chain for the modeling language which is used for describing business processes and workflows of an organization. This study examines yemeksepeti.com for providing an example of these two diagrams, which should be a milestone for the newcomers of an e-commerce. Organizing an e-commerce should start with the software designs and these examples of ERD and EDP which are the base for the software of an e-commerce business. The limitations of the paper include the examination of an only one company which operates only in Turkey, thus the further research should examine a global company and/or an e-commerce business that operates in several industries.展开更多
Purpose： This paper responds to the question, is exercise medicine？ It does so using a qualitative case study that proposes that exercise is recreation. The study （1） describes and reflects upon an exercise is rec...Purpose： This paper responds to the question, is exercise medicine？ It does so using a qualitative case study that proposes that exercise is recreation. The study （1） describes and reflects upon an exercise is recreation metaphor, （2） establishes the principles and processes used to develop a sport park within which exercise is recreation, and （3） presents a comparative analysis of the exercise is recreation approach with a UK quality framework for ＂exercise referrals＂. Methods： Four years of documentation were collated and placed into 14 categories： （1） university strategies, （2） plans of the site, （3） policy documents, （4） minutes of a steering group, （5） contemporary documents, （6） organisational charts, （7） responses to local government policies on sport, （8） consultation documents, （9） operational procedures, （10） facility specifications, （11） partnership agreements, （12） material relating to the university＇s work on events, （13） notes on the universities sport department, and （14） timetables. These data were analysed through a 4-stage process which used recreation as the analytical theme for a comparative analysis. Results： The characteristics of the exercise is recreation metaphor in this case are （1） a focus on the experience of the user, （2） the promotion of well-being, （3） the importance of community, （4） embracing inclusivity, （5） sport, （6） aesthetics, and （7） leisure time. The principles and processes used to develop the sport park were （1） custodianship, （2） partnerships, （3） values, （4） inter-professional working, （5） local heritage, （6） change, （7） the natural park environment, and （8） ＂riding the bike as you build it＂. The comparative analysis with a UK quality framework for ＂exercise referrals＂ clearly shows a difference from an exercise is recreation approach. Conclusion： Exercise is recreation and may enable individuals and communities to reach a state of well-being. ~ 2016 Production and hosting by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.展开更多
Currently, the integrated biomechanical studies on fish locomotion come into focus, so it is urgent to provide reliable and sys- tematic experimental results, and to establish a biomechanical ＂digital fish＂ database...Currently, the integrated biomechanical studies on fish locomotion come into focus, so it is urgent to provide reliable and sys- tematic experimental results, and to establish a biomechanical ＂digital fish＂ database for some typical fish species. Accord- ingly, based on the control framework of ＂Neural Control - Active Contraction of Muscle - Passive Deformation＂, the elec- tromyography （EMG） signals, the mechanical properties and the constitutive relationship of skin, muscle, and body trunk, as well as morphological parameters of crucian carp, are investigated with experiments, from which a simplified database of bio- mechanical ＂digital fish＂ is established. First, the EMG signals from three lateral superficial red muscles of crucian carp, which was evolving in the C-start movement, were acquired with a self-designing amplifier. The modes of muscle activity were also investigated. Secondly, the Young＇s modulus and the reduced relaxation function of crucian carp＇s skin and muscle were de- termined by failure tests and relaxation tests in uniaxial tensile ways, respectively. Viscoelastic models were adopted to deduce the constitutive relationship. The mechanical properties and the angular stiffness of different sites on the crucian carp＇s body trunk were obtained with dynamic bending experiments, where a self-designing dynamic bending test machine was employed. The conclusion was drawn regarding the body trunk of crucian carp under dynamic bending deformation as an approximate elastomer. According to the above experimental results, a possible benefit of body effective stiffness increasing with a little energy dissipation was discussed. Thirdly, the distribution of geometric parameters and weight parameters for a single experi- mental individual and multiple individuals of crucian carp was studied with experiments. Finally, considering all the above re- suits, generic experimental data were obtained by normalization, and a preliminary biomechanical ＂digital fish＂ database for crucian carp was established.展开更多
基金Project(2012 2X04012-011)supported by the Innovation Platform for Process Modeling and Simulation of Advanced Materials Processing Technologies,China
文摘The local and global mechanical responses of gas tungsten arc welds（GTAW） of a 2219-T87 aluminum alloy were investigated with experiment and numerical simulation.Digital image correlation（DIC） was used to access the local strain fields in transversely loaded welds and to determine the local stress-strain curves of various regions in the joint.The results show that the DIC method is efficient to acquire the local stress-strain curves but the curves of harder regions are incomplete because the stress and strain ranges are limited by the weakest region.With appropriate extrapolation,the complete local stress-strain curves were acquired and proved to be effective to predict the tensile behavior of the welded joint.During the tensile process,the fracture initiates from the weld toes owing to their plastic strain concentrations and then propagates along the fusion line,finally propagates into the partially melted zone（PMZ）.
基金Project (2010DFA52280) supported by International Science and Technology CooperationProject (20100470260) supported by China Postdoctoral Science Foundation
文摘The hot deformation behavior of Ti-3.0Al-3.7Cr-2.0Fe-0.1B (TACFB) titanium alloy was investigated using a Gleeble-1500D thermal simulator in the temperature range of 800-950 °C, at constant strain rate from 0.01 s-1 to 10 s-1 and with height reduction of 70%. Flow stress and microstructure evolution during hot compression of TACFB alloy were investigated. The processing map of TACFB alloy was obtained. The results indicate that the hot deformation behavior of TACFB alloy is sensitive to the deformation temperature and strain rate. The peak flow stress decreases with increasing the test temperature and decreasing the strain rate. The constitutive relationship of TACFB alloy was obtained on the base of Arrhenius equations. When the strain rates are higher than 1.0 s-1, the dynamic recrystallization occurs, and the higher the strain rates are, the more the recrystallization is.
文摘Electronic Commerce or E-Commerce is the concept of making trade in electronic environment which has emerged by the use of the internet in commerce and increased after 1995. Organizations started to use electronic commerce by internet facilities nearby their traditional marketing methods to increase their sales and profits. E-Commerce has many advantages when compared to traditional trade. This paper aims to take out these advantages for the companies which want to make use of electronic commerce and includes important advices for these companies. The paper also includes the basic version of an e-commerce business, by analysing one of the most successful firms in Turkey, yemeksepeti.com in terms of an Entity-Relationship Diagram （ERD） and Event Driven Process （EDP） to explain the organizations how an e-commerce business model should be constructed systematically. An ERD is a data modeling technique which graphically illustrates an information system＇s entities and the relationships between those entities. On the other hand, EDP is a chain for the modeling language which is used for describing business processes and workflows of an organization. This study examines yemeksepeti.com for providing an example of these two diagrams, which should be a milestone for the newcomers of an e-commerce. Organizing an e-commerce should start with the software designs and these examples of ERD and EDP which are the base for the software of an e-commerce business. The limitations of the paper include the examination of an only one company which operates only in Turkey, thus the further research should examine a global company and/or an e-commerce business that operates in several industries.
文摘Purpose： This paper responds to the question, is exercise medicine？ It does so using a qualitative case study that proposes that exercise is recreation. The study （1） describes and reflects upon an exercise is recreation metaphor, （2） establishes the principles and processes used to develop a sport park within which exercise is recreation, and （3） presents a comparative analysis of the exercise is recreation approach with a UK quality framework for ＂exercise referrals＂. Methods： Four years of documentation were collated and placed into 14 categories： （1） university strategies, （2） plans of the site, （3） policy documents, （4） minutes of a steering group, （5） contemporary documents, （6） organisational charts, （7） responses to local government policies on sport, （8） consultation documents, （9） operational procedures, （10） facility specifications, （11） partnership agreements, （12） material relating to the university＇s work on events, （13） notes on the universities sport department, and （14） timetables. These data were analysed through a 4-stage process which used recreation as the analytical theme for a comparative analysis. Results： The characteristics of the exercise is recreation metaphor in this case are （1） a focus on the experience of the user, （2） the promotion of well-being, （3） the importance of community, （4） embracing inclusivity, （5） sport, （6） aesthetics, and （7） leisure time. The principles and processes used to develop the sport park were （1） custodianship, （2） partnerships, （3） values, （4） inter-professional working, （5） local heritage, （6） change, （7） the natural park environment, and （8） ＂riding the bike as you build it＂. The comparative analysis with a UK quality framework for ＂exercise referrals＂ clearly shows a difference from an exercise is recreation approach. Conclusion： Exercise is recreation and may enable individuals and communities to reach a state of well-being. ~ 2016 Production and hosting by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.
基金supported by the National Natural Science Foundation of China (Grant No. 10832010)the Knowledge Innovation Project of the Chinese Academy of Sciences (Grant No. KJCX2-YW-L05)
文摘Currently, the integrated biomechanical studies on fish locomotion come into focus, so it is urgent to provide reliable and sys- tematic experimental results, and to establish a biomechanical ＂digital fish＂ database for some typical fish species. Accord- ingly, based on the control framework of ＂Neural Control - Active Contraction of Muscle - Passive Deformation＂, the elec- tromyography （EMG） signals, the mechanical properties and the constitutive relationship of skin, muscle, and body trunk, as well as morphological parameters of crucian carp, are investigated with experiments, from which a simplified database of bio- mechanical ＂digital fish＂ is established. First, the EMG signals from three lateral superficial red muscles of crucian carp, which was evolving in the C-start movement, were acquired with a self-designing amplifier. The modes of muscle activity were also investigated. Secondly, the Young＇s modulus and the reduced relaxation function of crucian carp＇s skin and muscle were de- termined by failure tests and relaxation tests in uniaxial tensile ways, respectively. Viscoelastic models were adopted to deduce the constitutive relationship. The mechanical properties and the angular stiffness of different sites on the crucian carp＇s body trunk were obtained with dynamic bending experiments, where a self-designing dynamic bending test machine was employed. The conclusion was drawn regarding the body trunk of crucian carp under dynamic bending deformation as an approximate elastomer. According to the above experimental results, a possible benefit of body effective stiffness increasing with a little energy dissipation was discussed. Thirdly, the distribution of geometric parameters and weight parameters for a single experi- mental individual and multiple individuals of crucian carp was studied with experiments. Finally, considering all the above re- suits, generic experimental data were obtained by normalization, and a preliminary biomechanical ＂digital fish＂ database for crucian carp was established.
