A semi-empirical interatomic potential formalism,the second-nearest-neighbor modified embedded-atom method(2NN MEAM),has been applied to obtaining interatomic potentials for the Co-W and Al-W binary system using previ...A semi-empirical interatomic potential formalism,the second-nearest-neighbor modified embedded-atom method(2NN MEAM),has been applied to obtaining interatomic potentials for the Co-W and Al-W binary system using previously developed MEAM potentials of Co,Al and W.The potential parameters were determined by fitting the experimental data on the enthalpy of formation,lattice parameter,melting point and elastic constants.The present potentials generally reproduce the fundamental physical properties of the Co-W and Al-W systems accurately.The lattice parameters,the enthalpy of formation,the thermal stability and the elastic constants match well with experiment and the first-principles results.The enthalpy of mixing and the enthalpy of formation and mixing of liquid are in good agreement with CALPHAD calculations.The potentials can be easily combined with already-developed MEAM potentials for binary cobalt systems and can be used to describe Co-Al-W-based multicomponent alloys,especially for interfacial properties.展开更多
A scheme is proposed for the generation of two-atom maximally entangled states and multi-atom maximally entangled states of W class. The scheme is based on the simultaneous resonant interaction of atoms with a single-...A scheme is proposed for the generation of two-atom maximally entangled states and multi-atom maximally entangled states of W class. The scheme is based on the simultaneous resonant interaction of atoms with a single-mode cavity field. It does not require accurate adjustment of the interaction time. The time needed to complete the generation does not increase with the number of the atom.展开更多
We propose a scheme for robustly storing multi-atom entangled states involving Bell states, three-particle W-state, n-particle W-like-states, generalized multi-particle W-states, n-particle GHZ-states, and partially e...We propose a scheme for robustly storing multi-atom entangled states involving Bell states, three-particle W-state, n-particle W-like-states, generalized multi-particle W-states, n-particle GHZ-states, and partially entangled states in cavity QED. Our scheme can preserve the internal structure of the entangled states above, with only generation of a global phase corresponding to each of entangled states during the storage of them. One single-mode cavity and n identical two-level atoms are required. Our scheme may be realized in the present technology. The idea may be also utilized to store multi-trapped-ion entangled states in linear ion trap.展开更多
A new method of modifying the conventional k-w turbulence model for comer separation is proposed in this paper. The production term in the w equation is modified using kinematic vorticity considering fluid rotation an...A new method of modifying the conventional k-w turbulence model for comer separation is proposed in this paper. The production term in the w equation is modified using kinematic vorticity considering fluid rotation and deformation in complex geometric boundary conditions. The corner separation flow in linear compressor cascades is calculated using the original k-w model, the modified k-w model and the Reynolds stress model (RSM). The numerical results of the modified model are compared with the available experimental data, as well as the corresponding results of the original k-w model and RSM. In terms of accuracy, the modified model, which significantly improves the performance of the original k-w model for predicting comer separation, is quite competitive with the RSM. However, the modified model, which has considerably lower computational cost is more robust than the RSM.展开更多
In this paper, the sum of standard generalized flames of Hilbert W^*-module is studied intensively by using operator-theoretic-methods, and some conditions are given to assure that the sum of two or more standard gen...In this paper, the sum of standard generalized flames of Hilbert W^*-module is studied intensively by using operator-theoretic-methods, and some conditions are given to assure that the sum of two or more standard generalized frames is a standard generalized frame.展开更多
The first wall of the fusion reactor is a plasma-facing component and is a key link to maintain the integrity of structure during thermal shock induced by plasma disruptions. Be and W/Cu functionally graded materials ...The first wall of the fusion reactor is a plasma-facing component and is a key link to maintain the integrity of structure during thermal shock induced by plasma disruptions. Be and W/Cu functionally graded materials are two kinds of important plas- ma-facing materials (PFM) of first wall in fusion reactor currently. Previous researches seldom comparatively evaluated the normal servicing and heat shock resistance performance of first walls with those two kinds of PFMs. And also there lacks cou- pled thermal/mechanical analysis on the heat shock process in consideration of multiple thermal/mechanical phenomena, such as material melting, solidification, evaporation, etc., which is significant to further understand the heat shock damage mecha- nism of the first wall with different PFMs. With the aim of learning more detailed mechanical mechanism of thermal shock damage and then improving the thermal shock resistance performance of different first wall designs, the coupled ther- mal/mechanical response of two typical ITER-like first walls with PFM of Be and functionally graded W-Cu respectively un- der the heat shock of 1 2 GW/m2 are computed by the finite element method. Special considerations of elastic-plastic defor- mation, material melting, and solidification are included in numerical models and methods. The mechanical response behaviors of different structures and materials under the normal servicing operation as well as plasma disruption conditions are analyzed and investigated comparatively. The results reveal that heat is mainly deposited on the PFM layer in thc high energy shock pulse induced by plasma disruptions, resulting in complex thermal stress change as well as mechanical itTeversible damage of thermal elastic and plastic expansion, contraction and yielding. Compared with the first wall with Be PFM, which mitigates the damages from heat shock at most only in the PFM layer with cost of whole PFM layer plastic yielding, the first wall with graded W-Cu PFM is demonstrated to be possessed both of higher heat shock resistance performance and normal servicing performance, provided its material gradient and cooling capacity are well optimized under practical loading conditions.展开更多
Explosion welding was carried out on the basis of vacuum hot melt W/CuCrZr composite plate.Metallurgical microscope,scanning electron microscope and energy dispersive X-ray spectroscope were used to observe the micros...Explosion welding was carried out on the basis of vacuum hot melt W/CuCrZr composite plate.Metallurgical microscope,scanning electron microscope and energy dispersive X-ray spectroscope were used to observe the microscopic morphology of the bonding interface.At the same time,combined with finite element calculations,the evolution mechanism of the interface of the hot melt explosion welded W/CuCrZr composite plate was explored.The results show that the interface bonding of the hot melt explosion welded W/CuCrZr composite plate is good and there is a cross-melting zone with 3–8μm in thickness,but cracks are developed on the W side.The numerical simulation reproduces the changes of pressure,stress,strain and internal energy at the bonding interface in the process of hot melt explosion welding.The location of the crack generated in the experiment coincides with the high stress position calculated by numerical simulation.The high pressure and high temperature near the hot melt explosion welding interface further promote the bonding of the interface.展开更多
First of all, this paper shows clearly careless mistake of Kornai Weibull queue model with the waiting buyers in J.Kornai , as well as Kornai Weibull queue model without waiters . Secondly, strictl...First of all, this paper shows clearly careless mistake of Kornai Weibull queue model with the waiting buyers in J.Kornai , as well as Kornai Weibull queue model without waiters . Secondly, strictly prove that revised model has `normal state', under more natural conditions. We advance theory of Kornai Weibull queue model such that deeply understand an abuse of the planned economy.展开更多
基金Project(51274167)supported by the National Natural Science Foundation of ChinaProject(LQ14E010002)supported by the Zhejiang Provincial Natural Science Foundation of ChinaProject(2E24692)supported by the KIST Institutional Programs,Korea
文摘A semi-empirical interatomic potential formalism,the second-nearest-neighbor modified embedded-atom method(2NN MEAM),has been applied to obtaining interatomic potentials for the Co-W and Al-W binary system using previously developed MEAM potentials of Co,Al and W.The potential parameters were determined by fitting the experimental data on the enthalpy of formation,lattice parameter,melting point and elastic constants.The present potentials generally reproduce the fundamental physical properties of the Co-W and Al-W systems accurately.The lattice parameters,the enthalpy of formation,the thermal stability and the elastic constants match well with experiment and the first-principles results.The enthalpy of mixing and the enthalpy of formation and mixing of liquid are in good agreement with CALPHAD calculations.The potentials can be easily combined with already-developed MEAM potentials for binary cobalt systems and can be used to describe Co-Al-W-based multicomponent alloys,especially for interfacial properties.
基金The project supported by Natural Science Foundation of Fujian Province of China under Grant No. JB05065
文摘A scheme is proposed for the generation of two-atom maximally entangled states and multi-atom maximally entangled states of W class. The scheme is based on the simultaneous resonant interaction of atoms with a single-mode cavity field. It does not require accurate adjustment of the interaction time. The time needed to complete the generation does not increase with the number of the atom.
基金The project partially supported by Natural Science Foundation of Hunan Province of China under Grant No. 05JJ30005, the Science Research Fund of Educational Department of Hunan Province under Grant Nos. 05C756 and 06C766, National Natural Science Foundation of China under Grant Nos. 10274093 and 10474118, the Foundation for Youth Core-Teachers of Hunan Province under Grant No. 2003165, and the Science Research Fund of Hunan Institute of Humanity and Science and Technology under Grant No. 2005A001.We would like to thank Dr. Wen-Xing Yang and Xiao-Long Zhang for many helpful discussions.
文摘We propose a scheme for robustly storing multi-atom entangled states involving Bell states, three-particle W-state, n-particle W-like-states, generalized multi-particle W-states, n-particle GHZ-states, and partially entangled states in cavity QED. Our scheme can preserve the internal structure of the entangled states above, with only generation of a global phase corresponding to each of entangled states during the storage of them. One single-mode cavity and n identical two-level atoms are required. Our scheme may be realized in the present technology. The idea may be also utilized to store multi-trapped-ion entangled states in linear ion trap.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51376001, 51420105008, 11572025 & 51136003)the National Basic Research Program of China (“973” Project) (Grant No. 2012CB720205 & 2014CB046405)+2 种基金the Beijing Higher Education Young Elite Teacher Projectthe Fundamental Research Funds for the Central Universitiesthe Innovation Foundation of BUAA for Ph D Graduates
文摘A new method of modifying the conventional k-w turbulence model for comer separation is proposed in this paper. The production term in the w equation is modified using kinematic vorticity considering fluid rotation and deformation in complex geometric boundary conditions. The corner separation flow in linear compressor cascades is calculated using the original k-w model, the modified k-w model and the Reynolds stress model (RSM). The numerical results of the modified model are compared with the available experimental data, as well as the corresponding results of the original k-w model and RSM. In terms of accuracy, the modified model, which significantly improves the performance of the original k-w model for predicting comer separation, is quite competitive with the RSM. However, the modified model, which has considerably lower computational cost is more robust than the RSM.
基金the National Natural Science Foundation of China (No. 10771101) and Chuangxin Funds of Nanjing University of Aeronautics and Astronautics (No. 987561).
文摘In this paper, the sum of standard generalized flames of Hilbert W^*-module is studied intensively by using operator-theoretic-methods, and some conditions are given to assure that the sum of two or more standard generalized frames is a standard generalized frame.
基金supported by the National Magnetic Confinement Fusion Science Program of China(Grant Nos.2015GB121007&2013GB113004)
文摘The first wall of the fusion reactor is a plasma-facing component and is a key link to maintain the integrity of structure during thermal shock induced by plasma disruptions. Be and W/Cu functionally graded materials are two kinds of important plas- ma-facing materials (PFM) of first wall in fusion reactor currently. Previous researches seldom comparatively evaluated the normal servicing and heat shock resistance performance of first walls with those two kinds of PFMs. And also there lacks cou- pled thermal/mechanical analysis on the heat shock process in consideration of multiple thermal/mechanical phenomena, such as material melting, solidification, evaporation, etc., which is significant to further understand the heat shock damage mecha- nism of the first wall with different PFMs. With the aim of learning more detailed mechanical mechanism of thermal shock damage and then improving the thermal shock resistance performance of different first wall designs, the coupled ther- mal/mechanical response of two typical ITER-like first walls with PFM of Be and functionally graded W-Cu respectively un- der the heat shock of 1 2 GW/m2 are computed by the finite element method. Special considerations of elastic-plastic defor- mation, material melting, and solidification are included in numerical models and methods. The mechanical response behaviors of different structures and materials under the normal servicing operation as well as plasma disruption conditions are analyzed and investigated comparatively. The results reveal that heat is mainly deposited on the PFM layer in thc high energy shock pulse induced by plasma disruptions, resulting in complex thermal stress change as well as mechanical itTeversible damage of thermal elastic and plastic expansion, contraction and yielding. Compared with the first wall with Be PFM, which mitigates the damages from heat shock at most only in the PFM layer with cost of whole PFM layer plastic yielding, the first wall with graded W-Cu PFM is demonstrated to be possessed both of higher heat shock resistance performance and normal servicing performance, provided its material gradient and cooling capacity are well optimized under practical loading conditions.
基金National Natural Science Foundation of China(12072363,12272374,12372373)Special Fund for Fundamental Research of the Central Universities(WK2480000008,WK2480000007,WK2320000049)Anhui Provincial Science and Technology Major Project(202003A05020035)。
文摘Explosion welding was carried out on the basis of vacuum hot melt W/CuCrZr composite plate.Metallurgical microscope,scanning electron microscope and energy dispersive X-ray spectroscope were used to observe the microscopic morphology of the bonding interface.At the same time,combined with finite element calculations,the evolution mechanism of the interface of the hot melt explosion welded W/CuCrZr composite plate was explored.The results show that the interface bonding of the hot melt explosion welded W/CuCrZr composite plate is good and there is a cross-melting zone with 3–8μm in thickness,but cracks are developed on the W side.The numerical simulation reproduces the changes of pressure,stress,strain and internal energy at the bonding interface in the process of hot melt explosion welding.The location of the crack generated in the experiment coincides with the high stress position calculated by numerical simulation.The high pressure and high temperature near the hot melt explosion welding interface further promote the bonding of the interface.
文摘First of all, this paper shows clearly careless mistake of Kornai Weibull queue model with the waiting buyers in J.Kornai , as well as Kornai Weibull queue model without waiters . Secondly, strictly prove that revised model has `normal state', under more natural conditions. We advance theory of Kornai Weibull queue model such that deeply understand an abuse of the planned economy.