In order to investigate the effect of invastion by pine wood nematode(PWN), this study analyzed several functional indices, i.e., the increment in DBH and stand volume and biomass, in the damaged stands with various m...In order to investigate the effect of invastion by pine wood nematode(PWN), this study analyzed several functional indices, i.e., the increment in DBH and stand volume and biomass, in the damaged stands with various mixed percentages of Pinus massoniana and P. thunbergii and with different levels of damage. According to the results of rate of change in increment of DBH and stand volume, the forest ecosystem resistance against PWN increased with a reduction in the mixed ratio of pine. The resistance was highest with a mixed percentage of 50%. The invasion of PWN changed the corresponding relationship of increment between DBH and stand volume(pure stands > 7:3 conifer and broadleaf > 6:4 conifer and broadleaf > 5:5 conifer and broadleaf) among the P. thunbergii stands when there is no damage, but for P. massoniana stands this phenomenon did not occur. For the increment rate of DBH and stand volume, this significant change in P. thunbergii forest indicates that the resistance of pure P. thunbergii forest was higher than that of P. massoniana. The invasion of PWN accelerates the succession from pure stands to mixed stands and then to the broadleaf evergreen stands.展开更多
On February 25, the Unit 1 of Ling’ao Nuclear Power Plant phase II underwent a 41-day-long hot functional test successfully with its major systems satisfying the requirements for
Two complementary firms＇ information sharing and security investment are investigated. When two complementary firms with heterogeneous assets are both breached, it is assumed that they suffer different losses which a...Two complementary firms＇ information sharing and security investment are investigated. When two complementary firms with heterogeneous assets are both breached, it is assumed that they suffer different losses which are associated with their information assets. Some insights about optimal strategies for the firms and the attacker are obtained by the game theory, which forms a comparison with those derived from substitutable firms, and those derived from complementary firms with homogenous loss. In addition, both the unit transform cost of investment and the extent of firms＇loss affect the optimal strategies.Assuming that firms can control information sharing, security investments and both of them, respectively, the effect of the social planner is further analyzed on the information sharing, firms＇ aggregate defence, the aggregate attack and social total cost. Finally, some policy advice is provided through numerical simulation. Results show that firms are willing to choose security investment centrally rather than individually, but an intervention in information sharing by the social planner may not necessarily be preferable.展开更多
In this paper, iterative or successive approximation methods for the Hamilton-Jacobi-Bellman-lsaacs equations （HJBIEs） arising in both deterministic and stochastic optimal control for affine nonlinear systems are de...In this paper, iterative or successive approximation methods for the Hamilton-Jacobi-Bellman-lsaacs equations （HJBIEs） arising in both deterministic and stochastic optimal control for affine nonlinear systems are developed. Convergence of the methods are established under fairly mild assumptions, and examples are solved to demonstrate the effectiveness of the methods. However, the results presented in the paper are preliminary, and do not yet imply in anyway that the solutions computed will be stabilizing. More improvements and experimentation will be required before a satisfactory algorithm is developed.展开更多
Background Persistence of slow pathway (SP) function after SP modification is not uncommon after successful rediofrequency (RF) ablation of typical AV nodal reentry tachycardia (AVNRT). Methods and results We compa...Background Persistence of slow pathway (SP) function after SP modification is not uncommon after successful rediofrequency (RF) ablation of typical AV nodal reentry tachycardia (AVNRT). Methods and results We compared two methods (maximal AH interval during decremental atrial stimlation vs occurrence of AV nodal echos or dual AV nodal physiology (DAVNP): ≥50 msec increment in AH interval with a 10 msec decrement in A1A2) for the assessment of SP function immediately and 40 minutes after successful RF modification of SP. In 31 consecutive patients (age: 51±16 years, 18 women, 13 men) with typical AVNRT, SP modification was performed using a combined anatomic and electrogram guided approach. Immediately after successful SP modification, AV nodal function was assessed. This was repeated 40 minutes later. RF modification of SP was successful in all 31 patients. There was no recurrance during a 5±3 month follow up period. There was no significant difference between the electrophysiological parameters immediately and University of Frankfurt, Germany (Li YG, Bogun F, Grnefeld G, Hohnloser SH and Goethe JW)40 min after successful SP modification. There was evidence of SP function in 14 patients (6 with DAVNP+AV nodal echoes, 8 with either DAVNP or AV nodal echos) immehiately after SP modification. These patients could be differentiated from the patients without remaining SP function by maximal AH interval (298±102 msec vs 198±72 msec, P=0.004). 40 minutes after the suucessful SP modification, 11 patients displayed SP function (4 patients with DAVNP+AV nodal echos, 7 patients with either DAVNP or AV nodal echos). These patients could also be differentiated from the remaining patients with the use of the maximal AH interval (294±89 msec vs 189±50 msec, P<0.001).[BHDFG3,WK9ZQ,WK6,WK10*2,WK5W]Befroe SP modificationImmediately after RF40 min after RF[BHDZG1*2,WK9ZQ,WK6,WK10*2,WK5W]AVNERP (msec)258±44310±116316±114AVBCL (msec)330±55384±113376±110VABCL (msec)306±67306± 66311±54Max AH (msec)337±96247±100233±86 Conclusion SP function assessed immediately and 40 minutes after a successful SP modification remains stable. SP function can be assessed reliable by maximal AH interval during decremental atrial stimulation.展开更多
基金financially supported by the National Key Basic Research Development Program (No.2009CB119200)the Forestry Public Welfare Industry Scientific Research Project (No.200904029-3)
文摘In order to investigate the effect of invastion by pine wood nematode(PWN), this study analyzed several functional indices, i.e., the increment in DBH and stand volume and biomass, in the damaged stands with various mixed percentages of Pinus massoniana and P. thunbergii and with different levels of damage. According to the results of rate of change in increment of DBH and stand volume, the forest ecosystem resistance against PWN increased with a reduction in the mixed ratio of pine. The resistance was highest with a mixed percentage of 50%. The invasion of PWN changed the corresponding relationship of increment between DBH and stand volume(pure stands > 7:3 conifer and broadleaf > 6:4 conifer and broadleaf > 5:5 conifer and broadleaf) among the P. thunbergii stands when there is no damage, but for P. massoniana stands this phenomenon did not occur. For the increment rate of DBH and stand volume, this significant change in P. thunbergii forest indicates that the resistance of pure P. thunbergii forest was higher than that of P. massoniana. The invasion of PWN accelerates the succession from pure stands to mixed stands and then to the broadleaf evergreen stands.
文摘On February 25, the Unit 1 of Ling’ao Nuclear Power Plant phase II underwent a 41-day-long hot functional test successfully with its major systems satisfying the requirements for
基金The National Natural Science Foundation of China(No.71371050)
文摘Two complementary firms＇ information sharing and security investment are investigated. When two complementary firms with heterogeneous assets are both breached, it is assumed that they suffer different losses which are associated with their information assets. Some insights about optimal strategies for the firms and the attacker are obtained by the game theory, which forms a comparison with those derived from substitutable firms, and those derived from complementary firms with homogenous loss. In addition, both the unit transform cost of investment and the extent of firms＇loss affect the optimal strategies.Assuming that firms can control information sharing, security investments and both of them, respectively, the effect of the social planner is further analyzed on the information sharing, firms＇ aggregate defence, the aggregate attack and social total cost. Finally, some policy advice is provided through numerical simulation. Results show that firms are willing to choose security investment centrally rather than individually, but an intervention in information sharing by the social planner may not necessarily be preferable.
文摘In this paper, iterative or successive approximation methods for the Hamilton-Jacobi-Bellman-lsaacs equations （HJBIEs） arising in both deterministic and stochastic optimal control for affine nonlinear systems are developed. Convergence of the methods are established under fairly mild assumptions, and examples are solved to demonstrate the effectiveness of the methods. However, the results presented in the paper are preliminary, and do not yet imply in anyway that the solutions computed will be stabilizing. More improvements and experimentation will be required before a satisfactory algorithm is developed.
文摘Background Persistence of slow pathway (SP) function after SP modification is not uncommon after successful rediofrequency (RF) ablation of typical AV nodal reentry tachycardia (AVNRT). Methods and results We compared two methods (maximal AH interval during decremental atrial stimlation vs occurrence of AV nodal echos or dual AV nodal physiology (DAVNP): ≥50 msec increment in AH interval with a 10 msec decrement in A1A2) for the assessment of SP function immediately and 40 minutes after successful RF modification of SP. In 31 consecutive patients (age: 51±16 years, 18 women, 13 men) with typical AVNRT, SP modification was performed using a combined anatomic and electrogram guided approach. Immediately after successful SP modification, AV nodal function was assessed. This was repeated 40 minutes later. RF modification of SP was successful in all 31 patients. There was no recurrance during a 5±3 month follow up period. There was no significant difference between the electrophysiological parameters immediately and University of Frankfurt, Germany (Li YG, Bogun F, Grnefeld G, Hohnloser SH and Goethe JW)40 min after successful SP modification. There was evidence of SP function in 14 patients (6 with DAVNP+AV nodal echoes, 8 with either DAVNP or AV nodal echos) immehiately after SP modification. These patients could be differentiated from the patients without remaining SP function by maximal AH interval (298±102 msec vs 198±72 msec, P=0.004). 40 minutes after the suucessful SP modification, 11 patients displayed SP function (4 patients with DAVNP+AV nodal echos, 7 patients with either DAVNP or AV nodal echos). These patients could also be differentiated from the remaining patients with the use of the maximal AH interval (294±89 msec vs 189±50 msec, P<0.001).[BHDFG3,WK9ZQ,WK6,WK10*2,WK5W]Befroe SP modificationImmediately after RF40 min after RF[BHDZG1*2,WK9ZQ,WK6,WK10*2,WK5W]AVNERP (msec)258±44310±116316±114AVBCL (msec)330±55384±113376±110VABCL (msec)306±67306± 66311±54Max AH (msec)337±96247±100233±86 Conclusion SP function assessed immediately and 40 minutes after a successful SP modification remains stable. SP function can be assessed reliable by maximal AH interval during decremental atrial stimulation.
