Newton’s theory of gravitation has been outdated by relativity theory explaining specific phenomena like perihelion precession of Mercury, light deflection and very recently the detection of gravitational waves. But ...Newton’s theory of gravitation has been outdated by relativity theory explaining specific phenomena like perihelion precession of Mercury, light deflection and very recently the detection of gravitational waves. But the disappearance of the obvious gravitational force and the variation of time are arguable concepts difficult to directly prove. Present methodology is based on hypotheses as expressed in a previous article: a universal time and an inertial mass variable according to the Lorentz factor (which could not be envisioned at Newton’s age). Because this methodology is mainly stood on Newtonian mechanics, it will be called neo-Newtonian mechanics. This theory is in coherence with the time of the Quantum Mechanics. In Newtonian mechanics, all forces, including gravitational force, are deducted from the linear momentum. Introducing the variable inertial mass, the result of the demonstration is an updated expression of the net force at high velocity: F = γ<sup>3</sup>m<sub>g</sub>a. If such a factor in γ<sup>3</sup> can look a bit strange at first sight for a force, let us remind that the lost energy in a synchrotron is already measured in γ<sup>4</sup>. Next article will be on the perihelion precession of Mercury within neo-Newtonian mechanics.展开更多
High strength steel thick plate is widely used in shipbuilding, pressure vessels, etc. , the balance between weld quality and welding efficiency is becoming a research focus. In this paper, double-sided double arc fia...High strength steel thick plate is widely used in shipbuilding, pressure vessels, etc. , the balance between weld quality and welding efficiency is becoming a research focus. In this paper, double-sided double arc fiat-overhead welding experiments for high strength steel thick plate were conducted. Microstructures of weld have been observed through optical microscope （OM） and scanning electron microscope （SEM）. Transformation of microstructures under thermal cycles of multi peaks was analyzed. Macro and micro hardness were also tested. The results show that the heat-affected zone （HAZ） near the fusion line experiences thermal cycles up to three times. The microstructures there are the most complex, including coarse lath martensite in original coarse-grained zone, and net-like structure along grain boundaries in critical reheat coarse-grained zone. After several times of tempering for bucking welding, the features of acicula and lath are weakened. Its microstructure approaches to the microstructure of base metal which is tempering sorbite. The hardness test shows that the maximum hardness occurs at critical reheat coarse-grained zone, the hardness of reticulation structure at grain boundary can be up to 450 HV.展开更多
文摘Newton’s theory of gravitation has been outdated by relativity theory explaining specific phenomena like perihelion precession of Mercury, light deflection and very recently the detection of gravitational waves. But the disappearance of the obvious gravitational force and the variation of time are arguable concepts difficult to directly prove. Present methodology is based on hypotheses as expressed in a previous article: a universal time and an inertial mass variable according to the Lorentz factor (which could not be envisioned at Newton’s age). Because this methodology is mainly stood on Newtonian mechanics, it will be called neo-Newtonian mechanics. This theory is in coherence with the time of the Quantum Mechanics. In Newtonian mechanics, all forces, including gravitational force, are deducted from the linear momentum. Introducing the variable inertial mass, the result of the demonstration is an updated expression of the net force at high velocity: F = γ<sup>3</sup>m<sub>g</sub>a. If such a factor in γ<sup>3</sup> can look a bit strange at first sight for a force, let us remind that the lost energy in a synchrotron is already measured in γ<sup>4</sup>. Next article will be on the perihelion precession of Mercury within neo-Newtonian mechanics.
基金Acknowledgments The authors gratefully acknowledge the financial support provided by the National Natural Science Foundation of China under grant No. 51175119.
文摘High strength steel thick plate is widely used in shipbuilding, pressure vessels, etc. , the balance between weld quality and welding efficiency is becoming a research focus. In this paper, double-sided double arc fiat-overhead welding experiments for high strength steel thick plate were conducted. Microstructures of weld have been observed through optical microscope （OM） and scanning electron microscope （SEM）. Transformation of microstructures under thermal cycles of multi peaks was analyzed. Macro and micro hardness were also tested. The results show that the heat-affected zone （HAZ） near the fusion line experiences thermal cycles up to three times. The microstructures there are the most complex, including coarse lath martensite in original coarse-grained zone, and net-like structure along grain boundaries in critical reheat coarse-grained zone. After several times of tempering for bucking welding, the features of acicula and lath are weakened. Its microstructure approaches to the microstructure of base metal which is tempering sorbite. The hardness test shows that the maximum hardness occurs at critical reheat coarse-grained zone, the hardness of reticulation structure at grain boundary can be up to 450 HV.
