Taking the application of virtual simulation technology of industrial robot in teaching as the researchobject, a detailed research is conducted on the importance of course, principles of curriculum development,curricu...Taking the application of virtual simulation technology of industrial robot in teaching as the researchobject, a detailed research is conducted on the importance of course, principles of curriculum development,curriculum objectives, teaching content, teaching methods, teaching process and assessment methods in severalaspects. And the actual teaching for a semester according to this research, through the virtual simulationteaching, improved teaching efficiency, improved the industrial robot application level and ability of thestudents, reduced the equipment failure rate, and laid a solid foundation for the subsequent course.展开更多
This study shows that there are two regions with high trace metal concentrations in the Bohai Bay, China. The numerical hydrodynamic model coupled with geochemical analysis was applied to understand the mass transport...This study shows that there are two regions with high trace metal concentrations in the Bohai Bay, China. The numerical hydrodynamic model coupled with geochemical analysis was applied to understand the mass transport and sedimentation in the bay. The modeling results show that the two regions are located within the residual current vortexes. Results from the particle-tracking model indicate that the trace metals released from the land sources enter the regions and take a relatively long residence time in the vortexes. The sediment radionuclide data indicates that the two regions experienced continuous and high sedimentation, and trace metals are prone to deposit in the regions. The correlations among trace metals, residual currents and radionuclides data suggest that the tides are the governing factor controlling the distributions of the trace metals in the bay. The consistence among these results also supports the reliabilities of the numerical simulation results of water and trace metal transport in this study.展开更多
An online survey conducted March 18–19,2020 on the official China CDC WeChat account platform was used to evaluate the effect of public education about masks usage during the new coronavirus disease 2019(COVID-19)epi...An online survey conducted March 18–19,2020 on the official China CDC WeChat account platform was used to evaluate the effect of public education about masks usage during the new coronavirus disease 2019(COVID-19)epidemic.Chinese nationals older than 18 were eligible for the survey.The survey collected 5,761 questionnaires from the 31 provinces,municipalities,and autonomous regions of China's Mainland.99.7%and 97.2%of the respondents answered correctly that respiratory droplets and direct contact were the main transmission routes.73.3%of the respondents considered COVID-19 to be‘serious’or‘very serious’.展开更多
Precast segmental column bridges exhibit various construction advantages in comparison to traditional monolithic column bridges.However,the lack of cognitions on seismic behaviors has seriously restricted their applic...Precast segmental column bridges exhibit various construction advantages in comparison to traditional monolithic column bridges.However,the lack of cognitions on seismic behaviors has seriously restricted their applications and developments.In this paper,comprehensive investigations are conducted to analyze the dynamic characteristics of precast segmental column bridges under near-fault,forward-directivity ground motions.First,the finite-element models of two comparable bridges with precast segmental columns and monolithic columns are constructed by using OpenSees software,and the nonlinearities of the bridges are considered.Next,three different earthquake loadings are meticulously set up to handle engineering problems,namely recorded near-and far-field ground motions,parameterized pulses,and pulse and residual components extracted from real records.Finally,based on the models and earthquake sets,extensive explorations are carried out.The results show that near-fault forward-directivity ground motions are more threatening than far-field ones;precast segmental column bridges may suffer more pounding impacts than monolithic bridges;the“narrow band”effect caused by near-fault,forward-directivity ground motions may occur in bridges with shorter periods than pulse periods;and pulse and residual components play different roles in seismic responses.展开更多
基金supported by Teaching Research Subjec of LiaoNing Mechatronics College(JYLX2017014)Educational science "13th Five-Year" planning subject of Liaoning province(JG18EB090)
文摘Taking the application of virtual simulation technology of industrial robot in teaching as the researchobject, a detailed research is conducted on the importance of course, principles of curriculum development,curriculum objectives, teaching content, teaching methods, teaching process and assessment methods in severalaspects. And the actual teaching for a semester according to this research, through the virtual simulationteaching, improved teaching efficiency, improved the industrial robot application level and ability of thestudents, reduced the equipment failure rate, and laid a solid foundation for the subsequent course.
基金financially supported in part by the Key Program of Tianjin Natural Science Foundation(Grant No.16JCZDJC39400)the National Key Research and Development Program of China(Grant No.2016YFC0502204)+1 种基金the National Natural Science Foundation of China(Grant No.21501042)China Scholarship Council
文摘This study shows that there are two regions with high trace metal concentrations in the Bohai Bay, China. The numerical hydrodynamic model coupled with geochemical analysis was applied to understand the mass transport and sedimentation in the bay. The modeling results show that the two regions are located within the residual current vortexes. Results from the particle-tracking model indicate that the trace metals released from the land sources enter the regions and take a relatively long residence time in the vortexes. The sediment radionuclide data indicates that the two regions experienced continuous and high sedimentation, and trace metals are prone to deposit in the regions. The correlations among trace metals, residual currents and radionuclides data suggest that the tides are the governing factor controlling the distributions of the trace metals in the bay. The consistence among these results also supports the reliabilities of the numerical simulation results of water and trace metal transport in this study.
文摘An online survey conducted March 18–19,2020 on the official China CDC WeChat account platform was used to evaluate the effect of public education about masks usage during the new coronavirus disease 2019(COVID-19)epidemic.Chinese nationals older than 18 were eligible for the survey.The survey collected 5,761 questionnaires from the 31 provinces,municipalities,and autonomous regions of China's Mainland.99.7%and 97.2%of the respondents answered correctly that respiratory droplets and direct contact were the main transmission routes.73.3%of the respondents considered COVID-19 to be‘serious’or‘very serious’.
基金National Natural Science Foundation of China under Grant Nos.U1434205 and 51678490the Major Research Plan of China National Railway Ministry of China under Grant Nos.2015G002-B and P2018G007the National Key R&D Program of China under Grant No.2017YFC1500803。
文摘Precast segmental column bridges exhibit various construction advantages in comparison to traditional monolithic column bridges.However,the lack of cognitions on seismic behaviors has seriously restricted their applications and developments.In this paper,comprehensive investigations are conducted to analyze the dynamic characteristics of precast segmental column bridges under near-fault,forward-directivity ground motions.First,the finite-element models of two comparable bridges with precast segmental columns and monolithic columns are constructed by using OpenSees software,and the nonlinearities of the bridges are considered.Next,three different earthquake loadings are meticulously set up to handle engineering problems,namely recorded near-and far-field ground motions,parameterized pulses,and pulse and residual components extracted from real records.Finally,based on the models and earthquake sets,extensive explorations are carried out.The results show that near-fault forward-directivity ground motions are more threatening than far-field ones;precast segmental column bridges may suffer more pounding impacts than monolithic bridges;the“narrow band”effect caused by near-fault,forward-directivity ground motions may occur in bridges with shorter periods than pulse periods;and pulse and residual components play different roles in seismic responses.
