We report on the properties of strong pulses from PSR B0656＋14 by analyzing the data obtained using the Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010.In 44 h of observational data,a total...We report on the properties of strong pulses from PSR B0656＋14 by analyzing the data obtained using the Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010.In 44 h of observational data,a total of 67 pulses with signal-to-noise ratios above a 5σthreshold were detected.The peak flux densities of these pulses are 58 to 194 times that of the average profile,and their pulse energies are 3 to 68 times that of the average pulse.These pulses are clustered around phases about 5-ahead of the peak of the average profile.Compared with the width of the average profile,they are relatively narrow,with the full widths at half-maximum ranging from 0.28 ° to 1.78 °.The distribution of pulse-energies follows a lognormal distribution.These sporadic strong pulses detected from PSR B0656＋14 have different characteristics from both typical giant pulses and its regular pulses.展开更多
Anti-Japanese War Cultural Activity is the cultural activity full of gunpowder. It is based on the politics, taking the crowed as the object, taking the criticism as the weapon, changing with the times. It hasthe sign...Anti-Japanese War Cultural Activity is the cultural activity full of gunpowder. It is based on the politics, taking the crowed as the object, taking the criticism as the weapon, changing with the times. It hasthe significance of milestone of national cultural activity.展开更多
The temporal-spatial pattern of linear cultural heritage in the context of the tourism industry is closely linked to heritage management.Using the 1800 km long Beijing-Hangzhou Grand Canal as an example,this study com...The temporal-spatial pattern of linear cultural heritage in the context of the tourism industry is closely linked to heritage management.Using the 1800 km long Beijing-Hangzhou Grand Canal as an example,this study compared the dynamic evolution of tourism businesses in Beijing,Liaocheng,and Yangzhou at three time points(2010,2015,and 2019)via nearest neighbor analysis,kernel density estimation,and the standard deviational ellipse.Next,a Geo-detector was used to examine the influencing factors.The results reveal significant growth regardless of the quantity or agglomeration degree from 2010 to 2019,and the direction of industrial expansion is consistent with the flow direction of the canal.Moreover,the explanatory powers of factors related to socioeconomic development and canal resources are obviously stronger than those of the natural environment.The findings of this study offer theoretical constructs and policy recommendations for the sustainable development of the Beijing-Hangzhou Grand Canal and other linear cultural heritage sites.展开更多
We consider a modified Markov branching process incorporating with both state-independent immigration-migration and resurrection. The effect of state-independent immigration-migration is firstly in- vestigated in deta...We consider a modified Markov branching process incorporating with both state-independent immigration-migration and resurrection. The effect of state-independent immigration-migration is firstly in- vestigated in detail. The explicit expressions for the extinction probabilities and mean extinction times are presented. The ergodicity and stability properties of the process incorporating with resurrection structure are then investigated. The conditions for recurrence, ergodicity and exponential ergodicity are obtained. An explicit expression for the equilibrium distribution is also presented. As a preparation, the criteria for regularity and uniqueness for such structure are firstly established.展开更多
基金funded by the National Natural Science Foundation of China(Grant No.10973026)
文摘We report on the properties of strong pulses from PSR B0656＋14 by analyzing the data obtained using the Urumqi 25-m radio telescope at 1540 MHz from August 2007 to September 2010.In 44 h of observational data,a total of 67 pulses with signal-to-noise ratios above a 5σthreshold were detected.The peak flux densities of these pulses are 58 to 194 times that of the average profile,and their pulse energies are 3 to 68 times that of the average pulse.These pulses are clustered around phases about 5-ahead of the peak of the average profile.Compared with the width of the average profile,they are relatively narrow,with the full widths at half-maximum ranging from 0.28 ° to 1.78 °.The distribution of pulse-energies follows a lognormal distribution.These sporadic strong pulses detected from PSR B0656＋14 have different characteristics from both typical giant pulses and its regular pulses.
文摘Anti-Japanese War Cultural Activity is the cultural activity full of gunpowder. It is based on the politics, taking the crowed as the object, taking the criticism as the weapon, changing with the times. It hasthe significance of milestone of national cultural activity.
基金The National Natural Science Foundation of China(42301273)The R&D Program of Beijing Municipal Education Commission(SM202210015004)The Beijing Central Axis Protection Foundation(DYKT-2023-015).
文摘The temporal-spatial pattern of linear cultural heritage in the context of the tourism industry is closely linked to heritage management.Using the 1800 km long Beijing-Hangzhou Grand Canal as an example,this study compared the dynamic evolution of tourism businesses in Beijing,Liaocheng,and Yangzhou at three time points(2010,2015,and 2019)via nearest neighbor analysis,kernel density estimation,and the standard deviational ellipse.Next,a Geo-detector was used to examine the influencing factors.The results reveal significant growth regardless of the quantity or agglomeration degree from 2010 to 2019,and the direction of industrial expansion is consistent with the flow direction of the canal.Moreover,the explanatory powers of factors related to socioeconomic development and canal resources are obviously stronger than those of the natural environment.The findings of this study offer theoretical constructs and policy recommendations for the sustainable development of the Beijing-Hangzhou Grand Canal and other linear cultural heritage sites.
基金supported by National Natural Science Foundations of China (Grant Nos. 10771216 and 11071259)
文摘We consider a modified Markov branching process incorporating with both state-independent immigration-migration and resurrection. The effect of state-independent immigration-migration is firstly in- vestigated in detail. The explicit expressions for the extinction probabilities and mean extinction times are presented. The ergodicity and stability properties of the process incorporating with resurrection structure are then investigated. The conditions for recurrence, ergodicity and exponential ergodicity are obtained. An explicit expression for the equilibrium distribution is also presented. As a preparation, the criteria for regularity and uniqueness for such structure are firstly established.
