L（ s, t）-labeling is a variation of graph coloring which is motivated by a special kind of the channel assignment problem. Let s and t be any two nonnegative integers. An L （s, t）-labeling of a graph G is an assig...L（ s, t）-labeling is a variation of graph coloring which is motivated by a special kind of the channel assignment problem. Let s and t be any two nonnegative integers. An L （s, t）-labeling of a graph G is an assignment of integers to the vertices of G such that adjacent vertices receive integers which differ by at least s, and vertices that are at distance of two receive integers which differ by at least t. Given an L（s, t） -labeling f of a graph G, the L（s, t） edge span of f, βst （ G, f） = max { ｜f（u） -f（v）｜： （ u, v） ∈ E（G） } is defined. The L（ s, t） edge span of G, βst（G）, is minβst（G,f）, where the minimum runs over all L（s, t）-labelings f of G. Let T be any tree with a maximum degree of △≥2. It is proved that if 2s≥t≥0, then βst（T） =（ [△/2 ] - 1）t ＋s; if 0≤2s 〈 t and △ is even, then βst（T） = [ （△ - 1） t/2 ] ; and if 0 ≤2s 〈 t and △ is odd, then βst（T） = （△ - 1） t/2 ＋ s. Thus, the L（s, t） edge spans of the Cartesian product of two paths and of the square lattice are completely determined.展开更多
For a graph G and two positive integers j and k an m-L j k -edge-labeling of G is an assignment from the set 0 1 … m-to the edges such that adjacent edges receive labels that differ by at least j and edges at distanc...For a graph G and two positive integers j and k an m-L j k -edge-labeling of G is an assignment from the set 0 1 … m-to the edges such that adjacent edges receive labels that differ by at least j and edges at distance two receive labels that differ by at least k.Theλ′j k-number of G denoted byλ′j k G is the minimum integer m overall m-L j k -edge-labeling of G.The necklace is a specific type of Halin graph.The L 1 2 -edge-labeling of necklaces is studied and the lower and upper bounds on λ′1 2-number for necklaces are given.Also both the lower and upper bounds are attainable.展开更多
Fast reciprocating probe systems （ FRPS ） are widely used in some tokamaks, such as JT- 60 U, TEXT and DIlI-D. The parameters with high temporal-spatial resolution are measured for boundary plasmas using these syste...Fast reciprocating probe systems （ FRPS ） are widely used in some tokamaks, such as JT- 60 U, TEXT and DIlI-D. The parameters with high temporal-spatial resolution are measured for boundary plasmas using these systems. The FRPS on HL-2A is developed, which is composed of transmission bar, digital grating displacement system, electromagnetic valves, stepping motor and so on. The high-pressure gas from the electromagnetic valves controlled by trigger signals provides the power to drive the transmission bar forward or backward. Reciprocating distance is 8 cm with the maximum speed of 1.5 m·s^-1.展开更多
A reliability based analysis method for a drilled shaft stabilized slope system is presented in this paper. The drilled shaft stabilization mechanisms for the slope were treated as the drilled shaft induced soil archi...A reliability based analysis method for a drilled shaft stabilized slope system is presented in this paper. The drilled shaft stabilization mechanisms for the slope were treated as the drilled shaft induced soil arching, which was quantified by the load transfer factor in the limited equilibrium analysis. However, due to the inherent uncertainties of the soil properties and the model error of the semi-empirical load transfer equation, an extension modification of the deterministic method into a probabilistic method is developed in this paper. The MCS （Monte Carlo simulation） with log-normal random variables has been employed to calculate the probability of failure （Pf） for the drilled shafts/slope system. The developed theories were coded into a computer program for analyzing complex slope geometry and slope profile conditions. Finally, a case study has been performed to illustrate the application analysis of the developed probability approach in drilled shafts/slope system.展开更多
The edge plasma characteristics are studied by a movable array of Mach/Reynolds stress/Langmuir 10-probes and fast reciprocating 4-probes in the boundary region. These probes can measure edge plasma temperature, densi...The edge plasma characteristics are studied by a movable array of Mach/Reynolds stress/Langmuir 10-probes and fast reciprocating 4-probes in the boundary region. These probes can measure edge plasma temperature, density, poloidal electric field, radial electric field, Reynolds stress, poloidal rotation velocities and their profiles obtained by changing the radial positions of the probe array in different discharges. Measurement resuits are used to analyze plasma confinement, turbulent fluctuations and their correlation. The fixed flush 3-probe arrays are mounted on the 4-divertor neutralization plates at the same toroidal cross-section in divertor chamber. These probes are used to measure the profiles of the electron temperature, density and float potential in divertor chamber.展开更多
Because the last closed flux-surface （LCFS） finally determines the shape of plasma cross-section, and the shaping of plasma is a key issue directly related with lots of the hot subjects of an advanced tokamak（AT） ...Because the last closed flux-surface （LCFS） finally determines the shape of plasma cross-section, and the shaping of plasma is a key issue directly related with lots of the hot subjects of an advanced tokamak（AT） and of a reactor, e. g., the control on the current density, equilibrium, scrapeoff layer（SOL）, aspects of edge particle and energy, high plasma kinetic energy, and of course, the MHD instability suppression, the further studies on the LCFS related subjects, e. g., its determination, flux loss, etc., are still tokamak research. It equilibrium, poloidal needed for present is also important to get precise LCFS-related equilibrium or configuration properties for the controls on an AT and for the understandings on the underlying basic physical issues in a discharge.展开更多
The Casimir effect of a piston for massless scalar fields which satisfy Dirichlet boundary conditions in the context of five-dimensional Randall- Sundrum models is studied. In these scenarios we derive and calculate t...The Casimir effect of a piston for massless scalar fields which satisfy Dirichlet boundary conditions in the context of five-dimensional Randall- Sundrum models is studied. In these scenarios we derive and calculate the expression for the Casimir force on the piston. We also discuss the Casimir force in the limit that one outer plate is moved to the remote place to show that the nature of the reduced force between the parallel plates left. In the Randall^undrum model involving two branes the two plates attract each other when they locate very closely, but the reduced Casimir force turns to be repulsive as the plates separation is not extremely tiny, which is against the experimental phenomena, meaning that the RSI model can not be acceptable. In the case of one brane model the shape of the reduced Casimir force is similar to that of the standard two-parallel-system in the four-dimensional fiat spacetimes while the sign of force remains negative.展开更多
Remote sensing data have been widely used in pre-hazard prevention/preparation, emergency response and post-hazard recovery monitoring. Hurricane Katrina caused serious damage to the environment, society and economy i...Remote sensing data have been widely used in pre-hazard prevention/preparation, emergency response and post-hazard recovery monitoring. Hurricane Katrina caused serious damage to the environment, society and economy in the southern United States in 2005. On the 10 th anniversary of Hurricane Katrina, we monitored the recovery process in New Orleans and the surrounding area based on remote sensing. Results from multi-source remote sensing data indicated that the average vegetation conditions of the affected areas have not fully recovered compared with the pre-disaster conditions, especially in the hurricane's landfall area. Analysis from moderate resolution Landsat data showed that many civil engineering works have been undertaken in the city of New Orleans to prevent future disasters. Frequent observation using highresolution images recorded the progress of some of these civil construction projects(e.g. the 17 th Street Canal pumping station) in New Orleans. In this case study, we illustrated the capabilities of remote sensing techniques in recovery monitoring following a natural disaster. International/institutional cooperation is suggested to improve Earth observation capability in hazard monitoring. More Chinese Earth observation data are expected to be used in international monitoring.展开更多
基金The National Natural Science Foundation of China(No10671033)Southeast University Science Foundation ( NoXJ0607230)
文摘L（ s, t）-labeling is a variation of graph coloring which is motivated by a special kind of the channel assignment problem. Let s and t be any two nonnegative integers. An L （s, t）-labeling of a graph G is an assignment of integers to the vertices of G such that adjacent vertices receive integers which differ by at least s, and vertices that are at distance of two receive integers which differ by at least t. Given an L（s, t） -labeling f of a graph G, the L（s, t） edge span of f, βst （ G, f） = max { ｜f（u） -f（v）｜： （ u, v） ∈ E（G） } is defined. The L（ s, t） edge span of G, βst（G）, is minβst（G,f）, where the minimum runs over all L（s, t）-labelings f of G. Let T be any tree with a maximum degree of △≥2. It is proved that if 2s≥t≥0, then βst（T） =（ [△/2 ] - 1）t ＋s; if 0≤2s 〈 t and △ is even, then βst（T） = [ （△ - 1） t/2 ] ; and if 0 ≤2s 〈 t and △ is odd, then βst（T） = （△ - 1） t/2 ＋ s. Thus, the L（s, t） edge spans of the Cartesian product of two paths and of the square lattice are completely determined.
基金The National Natural Science Foundation of China(No.10971025,10901035)
文摘For a graph G and two positive integers j and k an m-L j k -edge-labeling of G is an assignment from the set 0 1 … m-to the edges such that adjacent edges receive labels that differ by at least j and edges at distance two receive labels that differ by at least k.Theλ′j k-number of G denoted byλ′j k G is the minimum integer m overall m-L j k -edge-labeling of G.The necklace is a specific type of Halin graph.The L 1 2 -edge-labeling of necklaces is studied and the lower and upper bounds on λ′1 2-number for necklaces are given.Also both the lower and upper bounds are attainable.
文摘Fast reciprocating probe systems （ FRPS ） are widely used in some tokamaks, such as JT- 60 U, TEXT and DIlI-D. The parameters with high temporal-spatial resolution are measured for boundary plasmas using these systems. The FRPS on HL-2A is developed, which is composed of transmission bar, digital grating displacement system, electromagnetic valves, stepping motor and so on. The high-pressure gas from the electromagnetic valves controlled by trigger signals provides the power to drive the transmission bar forward or backward. Reciprocating distance is 8 cm with the maximum speed of 1.5 m·s^-1.
文摘A reliability based analysis method for a drilled shaft stabilized slope system is presented in this paper. The drilled shaft stabilization mechanisms for the slope were treated as the drilled shaft induced soil arching, which was quantified by the load transfer factor in the limited equilibrium analysis. However, due to the inherent uncertainties of the soil properties and the model error of the semi-empirical load transfer equation, an extension modification of the deterministic method into a probabilistic method is developed in this paper. The MCS （Monte Carlo simulation） with log-normal random variables has been employed to calculate the probability of failure （Pf） for the drilled shafts/slope system. The developed theories were coded into a computer program for analyzing complex slope geometry and slope profile conditions. Finally, a case study has been performed to illustrate the application analysis of the developed probability approach in drilled shafts/slope system.
文摘The edge plasma characteristics are studied by a movable array of Mach/Reynolds stress/Langmuir 10-probes and fast reciprocating 4-probes in the boundary region. These probes can measure edge plasma temperature, density, poloidal electric field, radial electric field, Reynolds stress, poloidal rotation velocities and their profiles obtained by changing the radial positions of the probe array in different discharges. Measurement resuits are used to analyze plasma confinement, turbulent fluctuations and their correlation. The fixed flush 3-probe arrays are mounted on the 4-divertor neutralization plates at the same toroidal cross-section in divertor chamber. These probes are used to measure the profiles of the electron temperature, density and float potential in divertor chamber.
基金Supported by the National Natural Science Foundation of China（10175022）, and Sichuan Provincial Youth Foundation for Science and Technology （04zp026-032）
文摘Because the last closed flux-surface （LCFS） finally determines the shape of plasma cross-section, and the shaping of plasma is a key issue directly related with lots of the hot subjects of an advanced tokamak（AT） and of a reactor, e. g., the control on the current density, equilibrium, scrapeoff layer（SOL）, aspects of edge particle and energy, high plasma kinetic energy, and of course, the MHD instability suppression, the further studies on the LCFS related subjects, e. g., its determination, flux loss, etc., are still tokamak research. It equilibrium, poloidal needed for present is also important to get precise LCFS-related equilibrium or configuration properties for the controls on an AT and for the understandings on the underlying basic physical issues in a discharge.
基金Supported by the Natural Science Foundation of China under Grant No.10875043the Shanghai Research Foundation under Grant No.07dz22020
文摘The Casimir effect of a piston for massless scalar fields which satisfy Dirichlet boundary conditions in the context of five-dimensional Randall- Sundrum models is studied. In these scenarios we derive and calculate the expression for the Casimir force on the piston. We also discuss the Casimir force in the limit that one outer plate is moved to the remote place to show that the nature of the reduced force between the parallel plates left. In the Randall^undrum model involving two branes the two plates attract each other when they locate very closely, but the reduced Casimir force turns to be repulsive as the plates separation is not extremely tiny, which is against the experimental phenomena, meaning that the RSI model can not be acceptable. In the case of one brane model the shape of the reduced Casimir force is similar to that of the standard two-parallel-system in the four-dimensional fiat spacetimes while the sign of force remains negative.
基金supported by the National Natural Science Foundation of China (41301445)a research grant from Tsinghua University (20151080351)
文摘Remote sensing data have been widely used in pre-hazard prevention/preparation, emergency response and post-hazard recovery monitoring. Hurricane Katrina caused serious damage to the environment, society and economy in the southern United States in 2005. On the 10 th anniversary of Hurricane Katrina, we monitored the recovery process in New Orleans and the surrounding area based on remote sensing. Results from multi-source remote sensing data indicated that the average vegetation conditions of the affected areas have not fully recovered compared with the pre-disaster conditions, especially in the hurricane's landfall area. Analysis from moderate resolution Landsat data showed that many civil engineering works have been undertaken in the city of New Orleans to prevent future disasters. Frequent observation using highresolution images recorded the progress of some of these civil construction projects(e.g. the 17 th Street Canal pumping station) in New Orleans. In this case study, we illustrated the capabilities of remote sensing techniques in recovery monitoring following a natural disaster. International/institutional cooperation is suggested to improve Earth observation capability in hazard monitoring. More Chinese Earth observation data are expected to be used in international monitoring.
