In this paper, the defect of the Two-Time Expansion method is indicated and an improvement of this method is suggested. Certain examples.in which the present method is used, are given. Moreover, the paper shows the eq...In this paper, the defect of the Two-Time Expansion method is indicated and an improvement of this method is suggested. Certain examples.in which the present method is used, are given. Moreover, the paper shows the equivalence of the improved Two-Time Expansion Method and the method of KBM(Kryloy-Bogoliuboy-Mitropolski).展开更多
Biology has been a brilliant teacher and a precious textbook to man-made construction for thousands of years, because it allows one to learn and be inspired by nature＇s remarkable and efficient structural systems. Ho...Biology has been a brilliant teacher and a precious textbook to man-made construction for thousands of years, because it allows one to learn and be inspired by nature＇s remarkable and efficient structural systems. However, the emerging biomimetic studies have been of increasing interest for civil engineering design only in the past two decades. Bridge design is one of aspects on structural engineering of biomimeties that offers an enormous potential for inspiration in various aspects, such as the ge- ometry, structure, mechanism, energy use and the intelligence. Recently built bridges and design proposals in which biological systems have produced a range of inspiration are reviewed in this paper. Multidisciplinary cooperation is discussed for the implementation of bio-inspired methods in future design. A case study about using bio-inspired strategy is trying to present a problem-solving approach, yet further cooperation is still needed to utilize biomimetie studies for design inspiration. This paper aims to call a close multidisciplinary collaboration that promotes engineers to build more sustainable and smart structural systems for bridges in the 21 st century.展开更多
In this paper, we introduce a quasi-one-dimensional S = 1 antiferromagnet Heisenberg model, and some physical properties of antiferromagnet L2BaNiO5 without antiferromagnet long-range-order above the Néel tempera...In this paper, we introduce a quasi-one-dimensional S = 1 antiferromagnet Heisenberg model, and some physical properties of antiferromagnet L2BaNiO5 without antiferromagnet long-range-order above the Néel temperature are analyzed based on the frame of two-time Green’s function theory. In a high temperature region, we calculate the correlation functions, and obtain excitation spectrum along Ni chains and the Haldane gap in this spectrum versus temperature. We find that the short-range correlation still exists at high temperature, which leads to the existence of Haldane gap in excitation spectrum. The increment of excitation energy in the spectrum along the Ni chain is found to be induced by the AF interaction between spins of rare-earth and Ni ions. Additionally, we also find that Haldane gap goes up with temperature increasing.展开更多
文摘In this paper, the defect of the Two-Time Expansion method is indicated and an improvement of this method is suggested. Certain examples.in which the present method is used, are given. Moreover, the paper shows the equivalence of the improved Two-Time Expansion Method and the method of KBM(Kryloy-Bogoliuboy-Mitropolski).
文摘Biology has been a brilliant teacher and a precious textbook to man-made construction for thousands of years, because it allows one to learn and be inspired by nature＇s remarkable and efficient structural systems. However, the emerging biomimetic studies have been of increasing interest for civil engineering design only in the past two decades. Bridge design is one of aspects on structural engineering of biomimeties that offers an enormous potential for inspiration in various aspects, such as the ge- ometry, structure, mechanism, energy use and the intelligence. Recently built bridges and design proposals in which biological systems have produced a range of inspiration are reviewed in this paper. Multidisciplinary cooperation is discussed for the implementation of bio-inspired methods in future design. A case study about using bio-inspired strategy is trying to present a problem-solving approach, yet further cooperation is still needed to utilize biomimetie studies for design inspiration. This paper aims to call a close multidisciplinary collaboration that promotes engineers to build more sustainable and smart structural systems for bridges in the 21 st century.
文摘In this paper, we introduce a quasi-one-dimensional S = 1 antiferromagnet Heisenberg model, and some physical properties of antiferromagnet L2BaNiO5 without antiferromagnet long-range-order above the Néel temperature are analyzed based on the frame of two-time Green’s function theory. In a high temperature region, we calculate the correlation functions, and obtain excitation spectrum along Ni chains and the Haldane gap in this spectrum versus temperature. We find that the short-range correlation still exists at high temperature, which leads to the existence of Haldane gap in excitation spectrum. The increment of excitation energy in the spectrum along the Ni chain is found to be induced by the AF interaction between spins of rare-earth and Ni ions. Additionally, we also find that Haldane gap goes up with temperature increasing.
