In order to explore the possible diffusion distance of carbon during proeutectoid ferrite transformation, a slow cooling test of low carbon steel was carried out under vacuum of the thermal simulator. The microstructu...In order to explore the possible diffusion distance of carbon during proeutectoid ferrite transformation, a slow cooling test of low carbon steel was carried out under vacuum of the thermal simulator. The microstructure and thermal expansion curve were discussed and the carbon concentration inside the sample was measured. The ferrite layer of about 450 μm thickness was obtained without pearlite on the surface of the sample in the microstructure. The thermal expansion curve shows that the ferrite layer without pearlite is formed during the local phase transformation, which is followed by the global transformation. The carbon concentration in the core of the sample (0.061%) is significantly higher than that of the bulk material (0.054%). All results show that carbon has long-range diffusion from the outer layer to the inner layer of the sample. The transformation is predominantly interface-controlled mode during local transformation, and the interface migration rate is about 2.25 μm/s.展开更多
We have theoretically studied the nucleation of superconductivity in doubly connected superconductors in the form of long superconducting cylinders. The giant vortex states are investigated with the nonlinear Ginzburg...We have theoretically studied the nucleation of superconductivity in doubly connected superconductors in the form of long superconducting cylinders. The giant vortex states are investigated with the nonlinear Ginzburg-Landau theory. The solutions of Ginzburg-Landau equations are solved numerically with relaxation method. The quantum size effect is clearly shown through the calculation of free energy.展开更多
Abstract： In the present study was investigated Arg-X protease-sensitive in supramolecular-genome compartments （nucleoplasm, chromatin, nuclear matrix）, during the period of the transcriptional activation of chroma...Abstract： In the present study was investigated Arg-X protease-sensitive in supramolecular-genome compartments （nucleoplasm, chromatin, nuclear matrix）, during the period of the transcriptional activation of chromatin when the growth processes was initiated in the mature germs of winter and transformed from it spring wheat. The germs have been separated from endosperm from 0 h （air-dry seed） up to 21 h in each 3 h after the start of seeds soaking. Cell nucleus have been allocated from germs and cleared, and then from them supramolecular-genome compartments were extracted by increasing ionic strength of solution. The Arg-X （tryptase） activity was assessed by cleavage of Arg-X bonds in the arginine-enriched protein protamine in all nuclear fractions. In the present study have shown what Arg-X protease-sensitives zones can be located on the supramolecular structures of chromatin matrix in processes of realization of ontogenetic programs of development in mature germs of the winter and transformed from it spring wheat. Arg-X protease-sensitive can translocate and coordinated in heteropolymer structures on the same genetic matrix. Questions of epigenetic mechanisms are discussed.展开更多
Two dimensional(2D)nanocrystal functional superlattices with a well controlled structure are of significant importance in photonic,plasmonic and optoelectronic applications and have been well studied,but it remains ch...Two dimensional(2D)nanocrystal functional superlattices with a well controlled structure are of significant importance in photonic,plasmonic and optoelectronic applications and have been well studied,but it remains challenging to understand the formation mechanism and development pathway of the superlattice.In this study,we employed in-situ liquid cell transmission electron microscopy to study the formation of 2D superlattice and its local phase transition from hexagonal-to-square nanocrystal ordering.When colloidal nanocrystals flowed in the solution,long-range ordered hexagonal superlattice could be formed either through shrinking and rearrangement of nanocrystal aggregates or via nanocrystal attachment.As the nanocrystals’shape transformed from truncated octahedral to cube,the local superlattice rearranged to square geometry.Moreover,our observations and quantitative analyses reveal that the phase transition from hexagonal to square mainly originates from the strong van der Waals interactions between the vertical(100)facets.The tracking of 2D cube superlattice formation in real-time could provide unique insights on the governing force of superlattice assembling and stabilization.展开更多
The existence of at least two homoclinic orbits for Lagrangian system (LS) is proved, wherethe Lagrangian L(t,x,y) =1/2∑aij(x)yiyj-V(t, x), in which the potential V(t,x) is globallysurperquadratic in x and T-periodic...The existence of at least two homoclinic orbits for Lagrangian system (LS) is proved, wherethe Lagrangian L(t,x,y) =1/2∑aij(x)yiyj-V(t, x), in which the potential V(t,x) is globallysurperquadratic in x and T-periodic in t. The Concentration-Compactness Lemma and Mini-max argument are used to prove the existences.展开更多
基金Project(16PJ1430200)supported by Shanghai Pujiang Program,China
文摘In order to explore the possible diffusion distance of carbon during proeutectoid ferrite transformation, a slow cooling test of low carbon steel was carried out under vacuum of the thermal simulator. The microstructure and thermal expansion curve were discussed and the carbon concentration inside the sample was measured. The ferrite layer of about 450 μm thickness was obtained without pearlite on the surface of the sample in the microstructure. The thermal expansion curve shows that the ferrite layer without pearlite is formed during the local phase transformation, which is followed by the global transformation. The carbon concentration in the core of the sample (0.061%) is significantly higher than that of the bulk material (0.054%). All results show that carbon has long-range diffusion from the outer layer to the inner layer of the sample. The transformation is predominantly interface-controlled mode during local transformation, and the interface migration rate is about 2.25 μm/s.
基金The project supported by Natural Science Foundation from Beijing Normal University.Acknowledgments H. Zhao wishes to thank Profs. Fang-Lin Peng, Jue- Lian Shen, and Jia-Cai Nie for helpful discussions
文摘We have theoretically studied the nucleation of superconductivity in doubly connected superconductors in the form of long superconducting cylinders. The giant vortex states are investigated with the nonlinear Ginzburg-Landau theory. The solutions of Ginzburg-Landau equations are solved numerically with relaxation method. The quantum size effect is clearly shown through the calculation of free energy.
文摘Abstract： In the present study was investigated Arg-X protease-sensitive in supramolecular-genome compartments （nucleoplasm, chromatin, nuclear matrix）, during the period of the transcriptional activation of chromatin when the growth processes was initiated in the mature germs of winter and transformed from it spring wheat. The germs have been separated from endosperm from 0 h （air-dry seed） up to 21 h in each 3 h after the start of seeds soaking. Cell nucleus have been allocated from germs and cleared, and then from them supramolecular-genome compartments were extracted by increasing ionic strength of solution. The Arg-X （tryptase） activity was assessed by cleavage of Arg-X bonds in the arginine-enriched protein protamine in all nuclear fractions. In the present study have shown what Arg-X protease-sensitives zones can be located on the supramolecular structures of chromatin matrix in processes of realization of ontogenetic programs of development in mature germs of the winter and transformed from it spring wheat. Arg-X protease-sensitive can translocate and coordinated in heteropolymer structures on the same genetic matrix. Questions of epigenetic mechanisms are discussed.
基金financially supported by the National Key Research and Development Program of China (2017YFA0206500)the National Natural Science Foundation of China (21673198, 21373008 and 21621091)
文摘Two dimensional(2D)nanocrystal functional superlattices with a well controlled structure are of significant importance in photonic,plasmonic and optoelectronic applications and have been well studied,but it remains challenging to understand the formation mechanism and development pathway of the superlattice.In this study,we employed in-situ liquid cell transmission electron microscopy to study the formation of 2D superlattice and its local phase transition from hexagonal-to-square nanocrystal ordering.When colloidal nanocrystals flowed in the solution,long-range ordered hexagonal superlattice could be formed either through shrinking and rearrangement of nanocrystal aggregates or via nanocrystal attachment.As the nanocrystals’shape transformed from truncated octahedral to cube,the local superlattice rearranged to square geometry.Moreover,our observations and quantitative analyses reveal that the phase transition from hexagonal to square mainly originates from the strong van der Waals interactions between the vertical(100)facets.The tracking of 2D cube superlattice formation in real-time could provide unique insights on the governing force of superlattice assembling and stabilization.
基金Project supported by the National Natural Science Foundation of China,and the Zhejiang Natural Science Foundation.
文摘The existence of at least two homoclinic orbits for Lagrangian system (LS) is proved, wherethe Lagrangian L(t,x,y) =1/2∑aij(x)yiyj-V(t, x), in which the potential V(t,x) is globallysurperquadratic in x and T-periodic in t. The Concentration-Compactness Lemma and Mini-max argument are used to prove the existences.
