Just before the new round of UN climate change conference in Bonn, a survey report, named as the Climate Change in the Chinese Mind 2017, was released in Beijing. The investigation was conducted in the form of a compu...Just before the new round of UN climate change conference in Bonn, a survey report, named as the Climate Change in the Chinese Mind 2017, was released in Beijing. The investigation was conducted in the form of a computer-assisted telephone survey with a sample size of 4,025 samples, covering 332 prefecture-level administrative units and four municipalities in China.Urban-rural proportion and sex proportion were specially taken into account, so as to demonstrate the Chinese public awareness objectively. The investigation measures the public awareness from six aspects, which includes climate change beliefs, impacts, response, policies, actions, and the assessment of the effectiveness of climate communication. This article presents the key findings of the survey and provides further insights behind the data.展开更多
We proposed an optimal design method to expand the bandwidth for the control of large hydraulic Stewart platform.The method is based on generalized natural frequency and takes hydraulic oil into consideration.A Lagran...We proposed an optimal design method to expand the bandwidth for the control of large hydraulic Stewart platform.The method is based on generalized natural frequency and takes hydraulic oil into consideration.A Lagrangian formulation which considers the whole leg inertia is presented to obtain the accurate equivalent mass matrix.Using the model,the effect of leg inertia and the influence of design parameters on the generalized natural frequency are investigated.Finally,numerical examples are presented to validate and confirm the efficiency of the mathematical model.The results show that the leg inertia,especially the piston part plays an important role in the dynamics.The optimum diameter ratio of the base to the moving platform is between 2 and 3,and the optimum joint angle ratio of the base to the moving platform is about 1.The smaller joint angles and a longer leg stroke are favorable for raising system frequencies.The system oil should be preprocessed for large platforms with a requirement for good dynamic performance.展开更多
基金sponsored by China Postdoctoral Science Fund(grant number.2017M610674)the National Nature Science Fund(Assessing the Impact of US'Withdrawal from Paris Agreement on the Structure and Institutions of Global Climate Governance,grant number.71741011)
文摘Just before the new round of UN climate change conference in Bonn, a survey report, named as the Climate Change in the Chinese Mind 2017, was released in Beijing. The investigation was conducted in the form of a computer-assisted telephone survey with a sample size of 4,025 samples, covering 332 prefecture-level administrative units and four municipalities in China.Urban-rural proportion and sex proportion were specially taken into account, so as to demonstrate the Chinese public awareness objectively. The investigation measures the public awareness from six aspects, which includes climate change beliefs, impacts, response, policies, actions, and the assessment of the effectiveness of climate communication. This article presents the key findings of the survey and provides further insights behind the data.
基金supported by the National Basic Research Program(973)of China(No.2006CB705400)the National Natural Science Founda-tion of China(No.50705082)the National Natural Science Fund for Distinguished Young Scholar(No.50425518),China
文摘We proposed an optimal design method to expand the bandwidth for the control of large hydraulic Stewart platform.The method is based on generalized natural frequency and takes hydraulic oil into consideration.A Lagrangian formulation which considers the whole leg inertia is presented to obtain the accurate equivalent mass matrix.Using the model,the effect of leg inertia and the influence of design parameters on the generalized natural frequency are investigated.Finally,numerical examples are presented to validate and confirm the efficiency of the mathematical model.The results show that the leg inertia,especially the piston part plays an important role in the dynamics.The optimum diameter ratio of the base to the moving platform is between 2 and 3,and the optimum joint angle ratio of the base to the moving platform is about 1.The smaller joint angles and a longer leg stroke are favorable for raising system frequencies.The system oil should be preprocessed for large platforms with a requirement for good dynamic performance.
