为解决半潜式平台浮体结构建造过程中产生的累积偏差问题,以陵水17-2浮式生产装置(Floating Production Unit,FPU)为研究对象,根据建造过程中产品精度控制要素的偏差传递关系建立浮体结构建造精度数据链模型。根据精度数据链中各关联要...为解决半潜式平台浮体结构建造过程中产生的累积偏差问题,以陵水17-2浮式生产装置(Floating Production Unit,FPU)为研究对象,根据建造过程中产品精度控制要素的偏差传递关系建立浮体结构建造精度数据链模型。根据精度数据链中各关联要素之间的逻辑关系,研究开发面向FPU浮体结构建造精度过程控制的数据管理系统,可实现数据采集、数据分析、问题处理等功能之间的数据流向、数据加工、数据存储、数据重用的关联和解耦,以及实际生产过程的精度控制映射流程。研究成果对于其他类型海洋平台结构物的建造也具有一定的扩展适应性。展开更多
In this paper, we consider FPU lattices with particles of unit mass. The dynamics of the system is described by the infinite system of second order differential equations qn=U＇（qn＋1-qu）-U＇（qn-qn-1）,n∈Z,where q...In this paper, we consider FPU lattices with particles of unit mass. The dynamics of the system is described by the infinite system of second order differential equations qn=U＇（qn＋1-qu）-U＇（qn-qn-1）,n∈Z,where qn denotes the displacement of the n-th lattice site and U is the potential of interaction between two adjacent particles. Inspired by previous work due to Szulkin and Weth （Ground state solutions for some indefinite variational problems, J. Funct. Anal., 257 （2009）, 3802- 3822）, we investigate the existence of solitary ground waves, i.e., nontrivial solutions with least possible energy.展开更多
The phonon relaxation and heat conduction in one-dimensional Fermi Pasta-Ulam （FPU） β lattices are studied by using molecular dynamics simulations. The phonon relaxation rate, which dominates the length dependence ...The phonon relaxation and heat conduction in one-dimensional Fermi Pasta-Ulam （FPU） β lattices are studied by using molecular dynamics simulations. The phonon relaxation rate, which dominates the length dependence of the FPU β lattice, is first calculated from the energy autoeorrelation function for different modes at various temperatures through equilibrium molecular dynamics simulations. We find that the relaxation rate as a function of wave number k is proportional to k^1.688, which leads to a N^0.41 divergence of the thermal conductivity in the framework of Green-Kubo relation. This is also in good agreement with the data obtained by non-equilibrium molecular dynamics simulations which estimate the length dependence exponent of the thermal conductivity as 0.415. Our results confirm the N^2/5 divergence in one-dimensional FPU β lattices. The effects of the heat flux on the thermal conductivity are also studied by imposing different temperature differences on the two ends of the lattices. We find that the thermal conductivity is insensitive to the heat flux under our simulation conditions. It implies that the linear response theory is applicable towards the heat conduction in one-dimensional FPU β lattices.展开更多
文摘为解决半潜式平台浮体结构建造过程中产生的累积偏差问题,以陵水17-2浮式生产装置(Floating Production Unit,FPU)为研究对象,根据建造过程中产品精度控制要素的偏差传递关系建立浮体结构建造精度数据链模型。根据精度数据链中各关联要素之间的逻辑关系,研究开发面向FPU浮体结构建造精度过程控制的数据管理系统,可实现数据采集、数据分析、问题处理等功能之间的数据流向、数据加工、数据存储、数据重用的关联和解耦,以及实际生产过程的精度控制映射流程。研究成果对于其他类型海洋平台结构物的建造也具有一定的扩展适应性。
基金supported by the Specialized Fund for the Doctoral Program of Higher Education and the National Natural Science Foundation of China
文摘In this paper, we consider FPU lattices with particles of unit mass. The dynamics of the system is described by the infinite system of second order differential equations qn=U＇（qn＋1-qu）-U＇（qn-qn-1）,n∈Z,where qn denotes the displacement of the n-th lattice site and U is the potential of interaction between two adjacent particles. Inspired by previous work due to Szulkin and Weth （Ground state solutions for some indefinite variational problems, J. Funct. Anal., 257 （2009）, 3802- 3822）, we investigate the existence of solitary ground waves, i.e., nontrivial solutions with least possible energy.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.50976052,51136001,and 50730006)the Program for New Century Excellent Talents in University,China+1 种基金the Tsinghua University Initiative Scientific Research Program,Chinathe Tsinghua National Laboratory for Information Science and Technology TNList Cross-discipline Foundation,China
文摘The phonon relaxation and heat conduction in one-dimensional Fermi Pasta-Ulam （FPU） β lattices are studied by using molecular dynamics simulations. The phonon relaxation rate, which dominates the length dependence of the FPU β lattice, is first calculated from the energy autoeorrelation function for different modes at various temperatures through equilibrium molecular dynamics simulations. We find that the relaxation rate as a function of wave number k is proportional to k^1.688, which leads to a N^0.41 divergence of the thermal conductivity in the framework of Green-Kubo relation. This is also in good agreement with the data obtained by non-equilibrium molecular dynamics simulations which estimate the length dependence exponent of the thermal conductivity as 0.415. Our results confirm the N^2/5 divergence in one-dimensional FPU β lattices. The effects of the heat flux on the thermal conductivity are also studied by imposing different temperature differences on the two ends of the lattices. We find that the thermal conductivity is insensitive to the heat flux under our simulation conditions. It implies that the linear response theory is applicable towards the heat conduction in one-dimensional FPU β lattices.
