Glu44, Glu48, Glu56 and Asp60 are the negatively charged residues located at the molecular surface of cytochrome b 5. Two mutants of cytochrome b 5 were prepared, in which two or all of these four residues were muta...Glu44, Glu48, Glu56 and Asp60 are the negatively charged residues located at the molecular surface of cytochrome b 5. Two mutants of cytochrome b 5 were prepared, in which two or all of these four residues were mutated to alanines. The mutations give rise to slightly positive shifts of the redox potentials of cytochrome b 5 and obvious decrease of the cytochrome b 5-cytochrome c binding constants and electron transfer rates. The crystal structures of the two mutants were determined at 0.18 nm resolution, showing no alteration in overall structures and exhibiting slight changes in the local conformations around the mutation sites as compared with the wild-type protein. Based on the crystal structure of the quadruple-site mutant, a model for the binding of this mutant with cytochrome c is proposed, which involves the salt bridges from Glu37, Glu38 and heme propionate of cytochrome b 5 to three lysines of cytochrome c and can well account for the properties and behaviors of this mutant.展开更多
This manuscript provides a comparison of the Hypersphere World-Universe Model (WUM) with the prevailing Big Bang Model (BBM) of the Standard Cosmology. The performed analysis of BBM shows that the Four Pillars of the ...This manuscript provides a comparison of the Hypersphere World-Universe Model (WUM) with the prevailing Big Bang Model (BBM) of the Standard Cosmology. The performed analysis of BBM shows that the Four Pillars of the Standard Cosmology are model-dependent and not strong enough to support the model. The angular momentum problem is one of the most critical problems in BBM. Standard Cosmology cannot explain how Galaxies and Extra Solar systems obtained their substantial orbital and rotational angular momenta, and why the orbital momentum of Jupiter is considerably larger than the rotational momentum of the Sun. WUM is the only cosmological model in existence that is consistent with the Law of Conservation of Angular Momentum. To be consistent with this Fundamental Law, WUM discusses in detail the Beginning of the World. The Model introduces Dark Epoch (spanning from the Beginning of the World for 0.4 billion years) when only Dark Matter Particles (DMPs) existed, and Luminous Epoch (ever since for 13.8 billion years). Big Bang discussed in Standard Cosmology is, in our view, transition from Dark Epoch to Luminous Epoch due to Rotational Fission of Overspinning Dark Matter (DM) Supercluster’s Cores. WUM envisions Matter carried from the Universe into the World from the fourth spatial dimension by DMPs. Ordinary Matter is a byproduct of DM annihilation. WUM solves a number of physical problems in contemporary Cosmology and Astrophysics through DMPs and their interactions: Angular Momentum problem in birth and subsequent evolution of Galaxies and Extrasolar systems—how do they obtain it;Fermi Bubbles—two large structures in gamma-rays and X-rays above and below Galactic center;Diversity of Gravitationally-Rounded Objects in Solar system;some problems in Solar and Geophysics [1]. WUM reveals Inter-Connectivity of Primary Cosmological Parameters and calculates their values, which are in good agreement with the latest results of their measurements.展开更多
In order to study the structure transition during calcination, nano-titania powders prepared by hydrolyzing precipitation approach and calcined at 300, 400, 500, 600 and 700 ℃ were characterized by XRD, TEM and elect...In order to study the structure transition during calcination, nano-titania powders prepared by hydrolyzing precipitation approach and calcined at 300, 400, 500, 600 and 700 ℃ were characterized by XRD, TEM and electron diffraction(ED), respectively. The results show that titania powders calcined below 500 ℃ are almost composed of anatase, rutile appears below 500 ℃ and its ratio increases gradually with increase of calcin temperature; nano-titania particles are smaller than 40 nm mostly and the dispersion is related to calcining temperature; the inter-planar distances of nano-anatase single crystalline change gradually when calcing temperature increases to 500 ℃; so do that of nano-rutile single crystalline when calcining temperature charges from 600 to 700 ℃. The conclusions can be drawn that the temperature of transformation from anatase to rutile is below 500 ℃ and the process carries on gradually. Both inter-planar distances and the structure of nano-titania transform gradually with increasing calcing temperature.展开更多
The half-industrial and half-agricultural working structure in rural China is a key phenomenon supporting China's industrialization and urbanization. Based on inter-generational division of labor, the current half...The half-industrial and half-agricultural working structure in rural China is a key phenomenon supporting China's industrialization and urbanization. Based on inter-generational division of labor, the current half-industrial and half-agricultural working structure has given birth to the elderly agriculture and mainstay agriculture, the latter of which has gone out of agricultural involution and to some extent changed the management philosophy of traditional agriculture, becoming a key direction of China's agricultural development. Such a structure has also shaped the "new three-generation family" and facilitated the expansion of middle-income rural groups. While supporting long-term farmers in rural China, it also paves the way for China's urbanization. This structure plays a significant role in the economic, political and social development of rural China. Therefore, this structure is a rural economic structure which concerns farmers' income structure and livelihood patterns. Meanwhile, it is also a rural political structure, village structure and family structure. Through development and refinement, the half-industrial and halfagricultural working structure in rural China has far extended the scope of a descriptive concept. As a dominant variable, the structure, along with its derivatives, through permutation and combination, can establish logical relationships and an interpretation chain among a variety of major economic, political and social phenomena in rural China. Therefore, it can expect to be constructed into an analyticity-oriented mid-level concept.展开更多
Flutter is a self-sustained vibration which could create serious damage to compressor blades.Improving the efficiency and accuracy of Fluid-Structure Interaction(FSI)method is crucial to flutter analysis.An efficient ...Flutter is a self-sustained vibration which could create serious damage to compressor blades.Improving the efficiency and accuracy of Fluid-Structure Interaction(FSI)method is crucial to flutter analysis.An efficient FSI method which combines a fast mesh deformation technology and Double-Passage Shape Correction(DPSC)method is proposed to predict blades flutter under traveling wave modes.Firstly,regarding the fluid domain as a pseudo elastic solid,the flow mesh deformation and blade vibration response can be quickly obtained by solving the governing equations of the holistic system composed of blade and pseudo elastic solid.Then,by storing and updating the Fourier coefficients on the circumferential boundary,the phase-lagged boundary condition is introduced into the computational domain.Finally,the aerodynamic stability for the blades of an axial compressor under various Inter-Blade Phase Angle(IBPA)is analyzed.The results show that the proposed method can effectively predict the characteristics of aerodynamic damping,aerodynamic force and blade displacement.And a conceptual model is proposed to describe the motion behavior of the shock wave.Compared with the multi-passage method,the proposed method obtains almost the same unstable IBPA interval and the blade displacement error is less than 3.4%.But the calculation time is significantly shortened especially in small IBPA cases.展开更多
文摘Glu44, Glu48, Glu56 and Asp60 are the negatively charged residues located at the molecular surface of cytochrome b 5. Two mutants of cytochrome b 5 were prepared, in which two or all of these four residues were mutated to alanines. The mutations give rise to slightly positive shifts of the redox potentials of cytochrome b 5 and obvious decrease of the cytochrome b 5-cytochrome c binding constants and electron transfer rates. The crystal structures of the two mutants were determined at 0.18 nm resolution, showing no alteration in overall structures and exhibiting slight changes in the local conformations around the mutation sites as compared with the wild-type protein. Based on the crystal structure of the quadruple-site mutant, a model for the binding of this mutant with cytochrome c is proposed, which involves the salt bridges from Glu37, Glu38 and heme propionate of cytochrome b 5 to three lysines of cytochrome c and can well account for the properties and behaviors of this mutant.
文摘This manuscript provides a comparison of the Hypersphere World-Universe Model (WUM) with the prevailing Big Bang Model (BBM) of the Standard Cosmology. The performed analysis of BBM shows that the Four Pillars of the Standard Cosmology are model-dependent and not strong enough to support the model. The angular momentum problem is one of the most critical problems in BBM. Standard Cosmology cannot explain how Galaxies and Extra Solar systems obtained their substantial orbital and rotational angular momenta, and why the orbital momentum of Jupiter is considerably larger than the rotational momentum of the Sun. WUM is the only cosmological model in existence that is consistent with the Law of Conservation of Angular Momentum. To be consistent with this Fundamental Law, WUM discusses in detail the Beginning of the World. The Model introduces Dark Epoch (spanning from the Beginning of the World for 0.4 billion years) when only Dark Matter Particles (DMPs) existed, and Luminous Epoch (ever since for 13.8 billion years). Big Bang discussed in Standard Cosmology is, in our view, transition from Dark Epoch to Luminous Epoch due to Rotational Fission of Overspinning Dark Matter (DM) Supercluster’s Cores. WUM envisions Matter carried from the Universe into the World from the fourth spatial dimension by DMPs. Ordinary Matter is a byproduct of DM annihilation. WUM solves a number of physical problems in contemporary Cosmology and Astrophysics through DMPs and their interactions: Angular Momentum problem in birth and subsequent evolution of Galaxies and Extrasolar systems—how do they obtain it;Fermi Bubbles—two large structures in gamma-rays and X-rays above and below Galactic center;Diversity of Gravitationally-Rounded Objects in Solar system;some problems in Solar and Geophysics [1]. WUM reveals Inter-Connectivity of Primary Cosmological Parameters and calculates their values, which are in good agreement with the latest results of their measurements.
文摘In order to study the structure transition during calcination, nano-titania powders prepared by hydrolyzing precipitation approach and calcined at 300, 400, 500, 600 and 700 ℃ were characterized by XRD, TEM and electron diffraction(ED), respectively. The results show that titania powders calcined below 500 ℃ are almost composed of anatase, rutile appears below 500 ℃ and its ratio increases gradually with increase of calcin temperature; nano-titania particles are smaller than 40 nm mostly and the dispersion is related to calcining temperature; the inter-planar distances of nano-anatase single crystalline change gradually when calcing temperature increases to 500 ℃; so do that of nano-rutile single crystalline when calcining temperature charges from 600 to 700 ℃. The conclusions can be drawn that the temperature of transformation from anatase to rutile is below 500 ℃ and the process carries on gradually. Both inter-planar distances and the structure of nano-titania transform gradually with increasing calcing temperature.
文摘The half-industrial and half-agricultural working structure in rural China is a key phenomenon supporting China's industrialization and urbanization. Based on inter-generational division of labor, the current half-industrial and half-agricultural working structure has given birth to the elderly agriculture and mainstay agriculture, the latter of which has gone out of agricultural involution and to some extent changed the management philosophy of traditional agriculture, becoming a key direction of China's agricultural development. Such a structure has also shaped the "new three-generation family" and facilitated the expansion of middle-income rural groups. While supporting long-term farmers in rural China, it also paves the way for China's urbanization. This structure plays a significant role in the economic, political and social development of rural China. Therefore, this structure is a rural economic structure which concerns farmers' income structure and livelihood patterns. Meanwhile, it is also a rural political structure, village structure and family structure. Through development and refinement, the half-industrial and halfagricultural working structure in rural China has far extended the scope of a descriptive concept. As a dominant variable, the structure, along with its derivatives, through permutation and combination, can establish logical relationships and an interpretation chain among a variety of major economic, political and social phenomena in rural China. Therefore, it can expect to be constructed into an analyticity-oriented mid-level concept.
基金The authors would like to acknowledge the support of the National Natural Science Foundation of China(No.51675406)the Basic Research Project Group,China(No.514010106-205).
文摘Flutter is a self-sustained vibration which could create serious damage to compressor blades.Improving the efficiency and accuracy of Fluid-Structure Interaction(FSI)method is crucial to flutter analysis.An efficient FSI method which combines a fast mesh deformation technology and Double-Passage Shape Correction(DPSC)method is proposed to predict blades flutter under traveling wave modes.Firstly,regarding the fluid domain as a pseudo elastic solid,the flow mesh deformation and blade vibration response can be quickly obtained by solving the governing equations of the holistic system composed of blade and pseudo elastic solid.Then,by storing and updating the Fourier coefficients on the circumferential boundary,the phase-lagged boundary condition is introduced into the computational domain.Finally,the aerodynamic stability for the blades of an axial compressor under various Inter-Blade Phase Angle(IBPA)is analyzed.The results show that the proposed method can effectively predict the characteristics of aerodynamic damping,aerodynamic force and blade displacement.And a conceptual model is proposed to describe the motion behavior of the shock wave.Compared with the multi-passage method,the proposed method obtains almost the same unstable IBPA interval and the blade displacement error is less than 3.4%.But the calculation time is significantly shortened especially in small IBPA cases.
