Marine plastic debris has been a pervasive issue since the last century, and research on its sources and fates plays a vital role in the establishment of mitigation measures. However, data on the quantity of plastic w...Marine plastic debris has been a pervasive issue since the last century, and research on its sources and fates plays a vital role in the establishment of mitigation measures. However, data on the quantity of plastic waste that enters the sea on a certain timescale remain largely unavailable in China. Here, we established a model using material flow analysis method based on life cycle assessment to follow plastic product from primary plastic to plastic waste with statistical data and monitoring data from accurate sources. This model can be used to estimate and forecast the annual input of plastic waste into the sea from China until 2020. In 2011, 0.547 3-0.751 5 million tons of plastic waste entered the seas in China, with a growth rate of 4.55% per year until 2017. And the amount will decrease to 0.257 1 to 0.353 1 million tons in 2020 under the influence of governmental management. The amount of plastic waste discharged from coastal areas calculated in this study was much larger than that from river, thus it is suggested to strengthen the governance and control of plastic waste in coastal fishery activities in China in order to reduce the amount of marine plastic waste input.展开更多
The physical-cover-oriented variational principle of nonlinear numerical manifold method (NNMM) for the analysis of plastical problems is put forward according to the displacement model and the characters of numerical...The physical-cover-oriented variational principle of nonlinear numerical manifold method (NNMM) for the analysis of plastical problems is put forward according to the displacement model and the characters of numerical manifold method (NMM). The theoretical calculating formulations and the controlling equation of NNMM are derived. As an example, the plate with a hole in the center is calculated and the results show that the solution precision and efficiency of NNMM are agreeable.展开更多
基金The National Key Research and Development Program of China under contract No.2016YFC1402200the National Natural Science Foundation of China under contract No.41676190
文摘Marine plastic debris has been a pervasive issue since the last century, and research on its sources and fates plays a vital role in the establishment of mitigation measures. However, data on the quantity of plastic waste that enters the sea on a certain timescale remain largely unavailable in China. Here, we established a model using material flow analysis method based on life cycle assessment to follow plastic product from primary plastic to plastic waste with statistical data and monitoring data from accurate sources. This model can be used to estimate and forecast the annual input of plastic waste into the sea from China until 2020. In 2011, 0.547 3-0.751 5 million tons of plastic waste entered the seas in China, with a growth rate of 4.55% per year until 2017. And the amount will decrease to 0.257 1 to 0.353 1 million tons in 2020 under the influence of governmental management. The amount of plastic waste discharged from coastal areas calculated in this study was much larger than that from river, thus it is suggested to strengthen the governance and control of plastic waste in coastal fishery activities in China in order to reduce the amount of marine plastic waste input.
文摘The physical-cover-oriented variational principle of nonlinear numerical manifold method (NNMM) for the analysis of plastical problems is put forward according to the displacement model and the characters of numerical manifold method (NMM). The theoretical calculating formulations and the controlling equation of NNMM are derived. As an example, the plate with a hole in the center is calculated and the results show that the solution precision and efficiency of NNMM are agreeable.
