In this paper the generalized equations for spinning space are investigated and the constants of motion are derived in terms of the solutions of these equations. We study the geodesic motion of the pseudo-classical sp...In this paper the generalized equations for spinning space are investigated and the constants of motion are derived in terms of the solutions of these equations. We study the geodesic motion of the pseudo-classical spinning particles in the spacetime produced by an idealized cosmic string and the non-extreme stationary axisymmetric black hole spacetime. The bound state orbits in a plane are discussed. We also show, for a conical spacetime and the Kerr spacetime, that the geodesic motion of spinning particles is different.展开更多
The inverse relationship between nitrate and temperature(N-T relationship) has been used to estimate new production from remotely sensed sea surface temperature at the regional or global scale of oceans. This study ai...The inverse relationship between nitrate and temperature(N-T relationship) has been used to estimate new production from remotely sensed sea surface temperature at the regional or global scale of oceans. This study aimed to develop a time-series model of the N-T relationship from automated, continuous hourly observations over two years on the coast of Halifax, Canada. The model demonstrated time-series variability of the N-T relationship at a coastal station on the Nova Scotia Shelf, with adjusted R 2 =0.999 4 and RMSE=0.025 7. The maximum residual value was 0.077. The annual temperature variations described a sine curve, and daily, weekly, and monthly variations fluctuated within the normal ranges, controlled by the local climate. The annual variation of nitrate concentration formed nearly a sine curve. Heavy or longlasting rainfall increased nitrate concentration by 4 to 30-fold in 24 h, and then the increased nitrogen was quickly depleted by phytoplankton growth in 10 to 48 h. In general, biological activity was a key factor in causing nitrate concentration change, dependent mainly on seawater temperature. The power function of the N-T relationship observed in our study area could be used to quickly estimate sea surface nitrate concentration, in combination with temperature data obtained by remote sensing.展开更多
Here we present a cyclicly symmetric non-vacuum spacetime, admitting closed timelike curves(CTCs) which appear after a certain instant of time,i.e.,a time-machine spacetime. The spacetime is asymptotically flat, freef...Here we present a cyclicly symmetric non-vacuum spacetime, admitting closed timelike curves(CTCs) which appear after a certain instant of time,i.e.,a time-machine spacetime. The spacetime is asymptotically flat, freefrom curvature singularities and a four-dimensional extension of the Misner space in curved spacetime. The spacetime is of type Ⅱ in the Petrov classification scheme and the matter field pure radiation satisfy the energy condition.展开更多
In this paper, we find that under a diffeomorphic of nonlinear geodesic equations are concerned with light-like extremal surfaces in curved spaeetimes. It is interesting to transformation of variables, the light-like ...In this paper, we find that under a diffeomorphic of nonlinear geodesic equations are concerned with light-like extremal surfaces in curved spaeetimes. It is interesting to transformation of variables, the light-like extremal surfaces can be described by a system Particularly, we investigate the light-like extremal surfaces in Schwarzschild spacetime in detail and some new special solutions are derived systematically with aim to compare with the known results and to illustrate the method.展开更多
基金＊The project supported by the National Basic Research Program of China under Grant No. 2003CB716300 and Natural Science Foundation of Hunan Educational Department under Grant Nos. 03A028 and 02C203
文摘In this paper the generalized equations for spinning space are investigated and the constants of motion are derived in terms of the solutions of these equations. We study the geodesic motion of the pseudo-classical spinning particles in the spacetime produced by an idealized cosmic string and the non-extreme stationary axisymmetric black hole spacetime. The bound state orbits in a plane are discussed. We also show, for a conical spacetime and the Kerr spacetime, that the geodesic motion of spinning particles is different.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences(Nos.KZCX2-YW-Q07-02,KSCX2-SW-132)the Project of Knowledge Innovation Program of South China Sea Institute of Oceanology(No.LYQ200701)the Special Grant for Postgraduate Research,Innovation and Practice,Chinese Academy of Sciences(No.52920-104)
文摘The inverse relationship between nitrate and temperature(N-T relationship) has been used to estimate new production from remotely sensed sea surface temperature at the regional or global scale of oceans. This study aimed to develop a time-series model of the N-T relationship from automated, continuous hourly observations over two years on the coast of Halifax, Canada. The model demonstrated time-series variability of the N-T relationship at a coastal station on the Nova Scotia Shelf, with adjusted R 2 =0.999 4 and RMSE=0.025 7. The maximum residual value was 0.077. The annual temperature variations described a sine curve, and daily, weekly, and monthly variations fluctuated within the normal ranges, controlled by the local climate. The annual variation of nitrate concentration formed nearly a sine curve. Heavy or longlasting rainfall increased nitrate concentration by 4 to 30-fold in 24 h, and then the increased nitrogen was quickly depleted by phytoplankton growth in 10 to 48 h. In general, biological activity was a key factor in causing nitrate concentration change, dependent mainly on seawater temperature. The power function of the N-T relationship observed in our study area could be used to quickly estimate sea surface nitrate concentration, in combination with temperature data obtained by remote sensing.
文摘Here we present a cyclicly symmetric non-vacuum spacetime, admitting closed timelike curves(CTCs) which appear after a certain instant of time,i.e.,a time-machine spacetime. The spacetime is asymptotically flat, freefrom curvature singularities and a four-dimensional extension of the Misner space in curved spacetime. The spacetime is of type Ⅱ in the Petrov classification scheme and the matter field pure radiation satisfy the energy condition.
基金Supported by National Natural Science Foundation of China under Grant Nos.11026151,11101001the Anhui Provincial University’s Natural Science Foundation under Grant No.KJ2010A130
文摘In this paper, we find that under a diffeomorphic of nonlinear geodesic equations are concerned with light-like extremal surfaces in curved spaeetimes. It is interesting to transformation of variables, the light-like extremal surfaces can be described by a system Particularly, we investigate the light-like extremal surfaces in Schwarzschild spacetime in detail and some new special solutions are derived systematically with aim to compare with the known results and to illustrate the method.
