The equilibrium geometries, relative stabilities, and electronic properties of MnAgm（M=Na, Li; n ＋ m ≤ 7） as well as pure Agn, Nan, Lin （n ≤ 7） clusters are systematically investigated by means of the density f...The equilibrium geometries, relative stabilities, and electronic properties of MnAgm（M=Na, Li; n ＋ m ≤ 7） as well as pure Agn, Nan, Lin （n ≤ 7） clusters are systematically investigated by means of the density functional theory. The optimized geometries reveal that for 2 ≤ n ≤ 7, there are significant similarities in geometry among pure Agn, Nan, and Lin clusters, and the transitions from planar to three-dimensional configurations occur at n = 7, 7, and 6, respectively. In contrast, the first three-dimensional （3D） structures are observed at n ＋ m = 5 for both NanAgm and LinAgm clusters. When n ＋ m ≥5, a striking feature is that the trigonal bipyramid becomes the main subunit of LinAgm. Furthermore, dramatic odd-even alternative behaviours are obtained in the fragmentation energies, secondorder difference energies, highest occupied and lowest unoccupied molecular orbital energy gaps, and chemical hardness for both pure and doped clusters. The analytic results exhibit that clusters with an even electronic configuration （2, 4, 6） possess the weakest chemical reactivity and more enhanced stability.展开更多
We have found two types of important exact solutions, compacton sohuttions, which are solitary waveswith the property that after colliding with their own kind, they re-emerge with the same coherent shape very much ast...We have found two types of important exact solutions, compacton sohuttions, which are solitary waveswith the property that after colliding with their own kind, they re-emerge with the same coherent shape very much asthe solitons do during a completely elastic interaction, in the (1+1)D, (1+2)D and even (1+3)D models, and dromionsolutions (exponentially decaying solutions in all direction) in many (1+2)D and (1+3)D models. In this paper, symmetryreductions in (1+-2)D are considered for the break soliton-type equation with fully nonlinear dispersion (called BS(m, n)equation) ut + b(um)xxy+ 4b(un uy)x = 0, which is a generalized model of (1+2)D break soliton equation ut +buxxy + 4buuy + 4bux-1uy = 0, by using the extended direct reduction method. As a result, six types of symmetryreductions are obtained. Starting from the reduction equations and some simple transformations, we obtain the solitarywave solutions ofBS(l, n) equations, compacton solutions ofBS(m, m - 1) equations and the compacton-like solution ofthe potential form (called PBS(3, 2)) wxt + b(umx )xxy + 4b(wnxwy)x = 0. In addition, we show that the variable fx uy dxadmits dromion solutions rather than the field u itself in BS(1, n) equation.展开更多
(m, k)-firm real-time or weakly hard real-time (WHRT) guarantee is becoming attractive as it closes the gap between hard and soft (or probabilistic) real-time guarantee, and enables finer granularity of real-time QoS ...(m, k)-firm real-time or weakly hard real-time (WHRT) guarantee is becoming attractive as it closes the gap between hard and soft (or probabilistic) real-time guarantee, and enables finer granularity of real-time QoS through adjusting m and k. For multiple streams with (m, k)-firm constraint sharing a single server, an on-line priority assignment policy based on the most recent k-length history of each stream called distance based priority (DBP) has been proposed to assign priority.In case of priority equality among these head-of-queue instances, Earliest Deadline First (EDF) is used. Under the context of WHRT schedule theory, DBP is the most popular, gets much attention and has many applications due to its straightforward priority assignment policy and easy implementation. However, DBP combined with EDF cannot always provide good performance, mainly because the initial DBP does not underline the rich information on deadline met/missed distribution,specially streams in various failure states which will travel different distances to restore success states. Considering how to effectively restore the success state of each individual stream from a failure state, an integrated DBP utilizing deadline met/missed distribution is proposed in this paper. Simulation results validated the performance improvement of this pro-posal.展开更多
基金Project supported by the Doctoral Education Fund of the Education Ministry of Chain （Grant No. 20100181110086） and the National Natural Science Foundation of China （Grant Nos. 11104190 and 10974138）.
文摘The equilibrium geometries, relative stabilities, and electronic properties of MnAgm（M=Na, Li; n ＋ m ≤ 7） as well as pure Agn, Nan, Lin （n ≤ 7） clusters are systematically investigated by means of the density functional theory. The optimized geometries reveal that for 2 ≤ n ≤ 7, there are significant similarities in geometry among pure Agn, Nan, and Lin clusters, and the transitions from planar to three-dimensional configurations occur at n = 7, 7, and 6, respectively. In contrast, the first three-dimensional （3D） structures are observed at n ＋ m = 5 for both NanAgm and LinAgm clusters. When n ＋ m ≥5, a striking feature is that the trigonal bipyramid becomes the main subunit of LinAgm. Furthermore, dramatic odd-even alternative behaviours are obtained in the fragmentation energies, secondorder difference energies, highest occupied and lowest unoccupied molecular orbital energy gaps, and chemical hardness for both pure and doped clusters. The analytic results exhibit that clusters with an even electronic configuration （2, 4, 6） possess the weakest chemical reactivity and more enhanced stability.
文摘We have found two types of important exact solutions, compacton sohuttions, which are solitary waveswith the property that after colliding with their own kind, they re-emerge with the same coherent shape very much asthe solitons do during a completely elastic interaction, in the (1+1)D, (1+2)D and even (1+3)D models, and dromionsolutions (exponentially decaying solutions in all direction) in many (1+2)D and (1+3)D models. In this paper, symmetryreductions in (1+-2)D are considered for the break soliton-type equation with fully nonlinear dispersion (called BS(m, n)equation) ut + b(um)xxy+ 4b(un uy)x = 0, which is a generalized model of (1+2)D break soliton equation ut +buxxy + 4buuy + 4bux-1uy = 0, by using the extended direct reduction method. As a result, six types of symmetryreductions are obtained. Starting from the reduction equations and some simple transformations, we obtain the solitarywave solutions ofBS(l, n) equations, compacton solutions ofBS(m, m - 1) equations and the compacton-like solution ofthe potential form (called PBS(3, 2)) wxt + b(umx )xxy + 4b(wnxwy)x = 0. In addition, we show that the variable fx uy dxadmits dromion solutions rather than the field u itself in BS(1, n) equation.
基金Project supported by the National Natural Science Foundation of
China (No. 60203030) and Advanced Research Program of France-
China (Nos. PRA SI01-04 PRA SI03-02)
文摘(m, k)-firm real-time or weakly hard real-time (WHRT) guarantee is becoming attractive as it closes the gap between hard and soft (or probabilistic) real-time guarantee, and enables finer granularity of real-time QoS through adjusting m and k. For multiple streams with (m, k)-firm constraint sharing a single server, an on-line priority assignment policy based on the most recent k-length history of each stream called distance based priority (DBP) has been proposed to assign priority.In case of priority equality among these head-of-queue instances, Earliest Deadline First (EDF) is used. Under the context of WHRT schedule theory, DBP is the most popular, gets much attention and has many applications due to its straightforward priority assignment policy and easy implementation. However, DBP combined with EDF cannot always provide good performance, mainly because the initial DBP does not underline the rich information on deadline met/missed distribution,specially streams in various failure states which will travel different distances to restore success states. Considering how to effectively restore the success state of each individual stream from a failure state, an integrated DBP utilizing deadline met/missed distribution is proposed in this paper. Simulation results validated the performance improvement of this pro-posal.
