Taking "three dimensions" of natural language, graphic language and symbolic language as tools, this paper explores the teaching of function symmetry in senior high school. The axisymmetric and central symme...Taking "three dimensions" of natural language, graphic language and symbolic language as tools, this paper explores the teaching of function symmetry in senior high school. The axisymmetric and central symmetry of the function itself and the axisymmetric and central symmetry between the two functions are explored respectively. On the basis of studying the problem of function symmetry, the universal applicability of the above three tools in high school mathematics teaching is further discussed and prospected. In high school, the symmetry, as one of the basic properties of functions, is not only the content that teachers should focus on in teaching, but also a key knowledge module that it is difficult for most students to understand deeply. Its importance need not be repeated.展开更多
In a series of experiments, a granular material in a rectangular container with two hollow cylinders was studied as it underwent horizontal vibrations. At the peak values of acceleration, novel swirling granular flows...In a series of experiments, a granular material in a rectangular container with two hollow cylinders was studied as it underwent horizontal vibrations. At the peak values of acceleration, novel swirling granular flows were observed in the cylinders while the grains cascaded down the outer surface of the piles that formed outside the cylinders. Computer simulations were performed that supported our interpretation of the behaviour observed in the experiments.展开更多
A simple approach to calculate the amplitude component of a wave front propagating in space from a hologram is proposed. It is able to calculate the amplitude distribution on a plane at any distance rapidly using a st...A simple approach to calculate the amplitude component of a wave front propagating in space from a hologram is proposed. It is able to calculate the amplitude distribution on a plane at any distance rapidly using a standard GPU. This is useful for analyzing and reconstructing the 3D image encoded on a hologram.展开更多
In this study,the effects of deep cryogenic treatment(DCT)on the mechanical and tribological properties of AISI D3 tool steel were investigated together with a systematic correlation between their hardness and wear re...In this study,the effects of deep cryogenic treatment(DCT)on the mechanical and tribological properties of AISI D3 tool steel were investigated together with a systematic correlation between their hardness and wear resistance.It was found that conventionally heat treated AISI D3 tool steel samples were significantly hardened via an additional DCT,which was attributed to the more retained austenite elimination,more homogenized carbide distribution and more reduction in carbide size in the samples.As a result,the hardened AISI D3 samples exhibited reductions in their friction and wear during rubbing against alumina and 100Cr6 steel balls under different normal loads due to the effectively hindered removal of surface materials.The results clearly showed that the DCT was an effective way to improve the mechanical and tribological properties of the AISI D3 tool steel samples as the tribological performance of the tool steel samples was significantly influenced by their hardness.展开更多
文摘Taking "three dimensions" of natural language, graphic language and symbolic language as tools, this paper explores the teaching of function symmetry in senior high school. The axisymmetric and central symmetry of the function itself and the axisymmetric and central symmetry between the two functions are explored respectively. On the basis of studying the problem of function symmetry, the universal applicability of the above three tools in high school mathematics teaching is further discussed and prospected. In high school, the symmetry, as one of the basic properties of functions, is not only the content that teachers should focus on in teaching, but also a key knowledge module that it is difficult for most students to understand deeply. Its importance need not be repeated.
文摘In a series of experiments, a granular material in a rectangular container with two hollow cylinders was studied as it underwent horizontal vibrations. At the peak values of acceleration, novel swirling granular flows were observed in the cylinders while the grains cascaded down the outer surface of the piles that formed outside the cylinders. Computer simulations were performed that supported our interpretation of the behaviour observed in the experiments.
基金the UK Engineering and Physical Sciences Research Council (EPSRC) for the support through the Platform Grant in Liquid Crystal Photonics
文摘A simple approach to calculate the amplitude component of a wave front propagating in space from a hologram is proposed. It is able to calculate the amplitude distribution on a plane at any distance rapidly using a standard GPU. This is useful for analyzing and reconstructing the 3D image encoded on a hologram.
文摘In this study,the effects of deep cryogenic treatment(DCT)on the mechanical and tribological properties of AISI D3 tool steel were investigated together with a systematic correlation between their hardness and wear resistance.It was found that conventionally heat treated AISI D3 tool steel samples were significantly hardened via an additional DCT,which was attributed to the more retained austenite elimination,more homogenized carbide distribution and more reduction in carbide size in the samples.As a result,the hardened AISI D3 samples exhibited reductions in their friction and wear during rubbing against alumina and 100Cr6 steel balls under different normal loads due to the effectively hindered removal of surface materials.The results clearly showed that the DCT was an effective way to improve the mechanical and tribological properties of the AISI D3 tool steel samples as the tribological performance of the tool steel samples was significantly influenced by their hardness.
