Coordinated numerical ensemble experiments with six different state-of-the-art atmosphere models were used to evaluate and quantify the impact of global SST(from reanalysis data)on the early winter Arctic warming duri...Coordinated numerical ensemble experiments with six different state-of-the-art atmosphere models were used to evaluate and quantify the impact of global SST(from reanalysis data)on the early winter Arctic warming during 1982-2014.Two sets of experiments were designed:in the first set(EXP1),OISSTv2 daily sea-ice concentration and SST variations were used as the lower boundary forcing,while in the second set(EXP2)the SST data were replaced by the daily SST climatology.In the results,the multi-model ensemble mean of EXP1 showed a nearsurface(~850 hPa)warming trend of 0.4℃/10 yr,which was 80%of the warming trend in the reanalysis.The simulated warming trend was robust across the six models,with a magnitude of 0.36-0.50℃/10 yr.The global SST could explain most of the simulated warming trend in EXP1 in the mid and low troposphere over the Arctic,and accounted for 58%of the simulated near-surface warming.The results also suggest that the uppertropospheric warming(~200 hPa)over the Arctic in the reanalysis is likely not a forced signal;rather,it is caused by natural climate variability.The source regions that can potentially impact the early winter Arctic warming are explored and the limitations of the study are discussed.展开更多
This paper presents the forms of the general solution for general anisotropic piezoelectric media starting from the basic equations of piezoelasticity by using the operator method introduced by Lur’e (1964), and give...This paper presents the forms of the general solution for general anisotropic piezoelectric media starting from the basic equations of piezoelasticity by using the operator method introduced by Lur’e (1964), and gives the analytical form of the general solution for special orthotropic piezoelectric media. This paper uses the non-uniqueness of the general solution to obtain the generalized LHN solution and the generalized E-L solution for special orthotropic piezoelectric media. When the special orthotropic piezoelectric media degenerate to transversely piezoelectric media, the solution given by this paper degenerates to the solution for transversely isotropic piezoelectric media accordingly, so that this paper generalized the results in transversely isotropic piezoelectric media.展开更多
The purpose of this paper was to find out whether the higher education has met the necessary requirements for the implementation of the ICT system, in particular the e-learning system in higher education of seafarers....The purpose of this paper was to find out whether the higher education has met the necessary requirements for the implementation of the ICT system, in particular the e-learning system in higher education of seafarers. The goal was to explore to what extent the technical and organisational prerequisites for introducing the system have been fulfilled at the very institution--E-learning system provider, and to what extent the full-time maritime students and part-time students-seafarers are ready and trained to adopt such a system. In order to gather insights and make conclusions, the analytical method and the survey of students were used. A total of 930 full-time and part-time students （seafarers） were surveyed. The goal of these surveys was to find out the educational needs of both student groups, as well as their technical preconditions （e.g., having a PC at work or at home, access to the intemet, and the like） and competencies （e.g., computer literacy） that are necessary for active involvement in the e-learning system. A particularly interesting part of the research tackled the psychological predisposition of students, i.e., whether they were willing to use the system at all. A special part of the research was focused on issues regarding the costs and the available time that the students/seafarers have for using the e-learning system. The research has revealed that there are neither obstacles nor initial constraints for the implementation of the e-learning system in education of maritime students and seafarers at the University of Split. Moreover, the students have a positive attitude towards the e-learning system, and most of them are very enthusiastic about its implementation. The scientific contribution of this paper is provided by an analytical model exploring and defining the necessary prerequisites for introducing the e-learning system. The advantage of the model lies in its wide and multi-disciplinary approach to all these prerequisites, ranging from psychological to purely technical, financial, time, organisational and other aspects. An interesting issue is the question of＂good will＂ for launching such systems at the institutions which obviously meet all necessary prerequisites for their introduction, including the enthusiasm of their students and teachers. The case study shows that, apparently, the university management and the wider community have not recognised many a benefit of the e-learning system. This sounds paradoxical as it is precisely the very academic community that should act as the designer and the initiator of social changes, in social systems in general and in education systems in particular.展开更多
基金supported by the National Key R&D Program of China[grant number 2017YFE0111800]the National Natural Science Foundation of China[grant numbers 41790472 and 41661144005]partly supported by the EU H2020 Blue-Action project[grant number 727852]。
文摘Coordinated numerical ensemble experiments with six different state-of-the-art atmosphere models were used to evaluate and quantify the impact of global SST(from reanalysis data)on the early winter Arctic warming during 1982-2014.Two sets of experiments were designed:in the first set(EXP1),OISSTv2 daily sea-ice concentration and SST variations were used as the lower boundary forcing,while in the second set(EXP2)the SST data were replaced by the daily SST climatology.In the results,the multi-model ensemble mean of EXP1 showed a nearsurface(~850 hPa)warming trend of 0.4℃/10 yr,which was 80%of the warming trend in the reanalysis.The simulated warming trend was robust across the six models,with a magnitude of 0.36-0.50℃/10 yr.The global SST could explain most of the simulated warming trend in EXP1 in the mid and low troposphere over the Arctic,and accounted for 58%of the simulated near-surface warming.The results also suggest that the uppertropospheric warming(~200 hPa)over the Arctic in the reanalysis is likely not a forced signal;rather,it is caused by natural climate variability.The source regions that can potentially impact the early winter Arctic warming are explored and the limitations of the study are discussed.
基金Project (No. 10372003) supported by the National Natural Science Foundation of China
文摘This paper presents the forms of the general solution for general anisotropic piezoelectric media starting from the basic equations of piezoelasticity by using the operator method introduced by Lur’e (1964), and gives the analytical form of the general solution for special orthotropic piezoelectric media. This paper uses the non-uniqueness of the general solution to obtain the generalized LHN solution and the generalized E-L solution for special orthotropic piezoelectric media. When the special orthotropic piezoelectric media degenerate to transversely piezoelectric media, the solution given by this paper degenerates to the solution for transversely isotropic piezoelectric media accordingly, so that this paper generalized the results in transversely isotropic piezoelectric media.
文摘The purpose of this paper was to find out whether the higher education has met the necessary requirements for the implementation of the ICT system, in particular the e-learning system in higher education of seafarers. The goal was to explore to what extent the technical and organisational prerequisites for introducing the system have been fulfilled at the very institution--E-learning system provider, and to what extent the full-time maritime students and part-time students-seafarers are ready and trained to adopt such a system. In order to gather insights and make conclusions, the analytical method and the survey of students were used. A total of 930 full-time and part-time students （seafarers） were surveyed. The goal of these surveys was to find out the educational needs of both student groups, as well as their technical preconditions （e.g., having a PC at work or at home, access to the intemet, and the like） and competencies （e.g., computer literacy） that are necessary for active involvement in the e-learning system. A particularly interesting part of the research tackled the psychological predisposition of students, i.e., whether they were willing to use the system at all. A special part of the research was focused on issues regarding the costs and the available time that the students/seafarers have for using the e-learning system. The research has revealed that there are neither obstacles nor initial constraints for the implementation of the e-learning system in education of maritime students and seafarers at the University of Split. Moreover, the students have a positive attitude towards the e-learning system, and most of them are very enthusiastic about its implementation. The scientific contribution of this paper is provided by an analytical model exploring and defining the necessary prerequisites for introducing the e-learning system. The advantage of the model lies in its wide and multi-disciplinary approach to all these prerequisites, ranging from psychological to purely technical, financial, time, organisational and other aspects. An interesting issue is the question of＂good will＂ for launching such systems at the institutions which obviously meet all necessary prerequisites for their introduction, including the enthusiasm of their students and teachers. The case study shows that, apparently, the university management and the wider community have not recognised many a benefit of the e-learning system. This sounds paradoxical as it is precisely the very academic community that should act as the designer and the initiator of social changes, in social systems in general and in education systems in particular.
