Objective Spherical micro-particles are often preserved in Precambrian sedimentary rocks. Finnish and Chinese scholars have previously discovered carbonaceous, siliceous or ferruginous spherules of out-space origin in...Objective Spherical micro-particles are often preserved in Precambrian sedimentary rocks. Finnish and Chinese scholars have previously discovered carbonaceous, siliceous or ferruginous spherules of out-space origin in the 1.6 Ga and 1.4 Ga sequence, respectively. The presence of spherules can record possible cosmic impact events. Also, cosmic spherules provide important information on the evolution of planets from outer space.展开更多
The world's first woman president was Isabel Martinez de Peron(b.1931).In July,1974,Juan Domingo Peron,the president of Argentina,died,leaving his wife Isabel Martinez de Peron,then the vice-president,to succeed h...The world's first woman president was Isabel Martinez de Peron(b.1931).In July,1974,Juan Domingo Peron,the president of Argentina,died,leaving his wife Isabel Martinez de Peron,then the vice-president,to succeed him according to the cons stitution.展开更多
Zeng Xiaolan called her April trip to Beijing"mind-blowing"."The Forbidden City is so big and magnificent.I'd only seen it on TV before,"said the 14-year-old from Qinghai,a sparsely populated p...Zeng Xiaolan called her April trip to Beijing"mind-blowing"."The Forbidden City is so big and magnificent.I'd only seen it on TV before,"said the 14-year-old from Qinghai,a sparsely populated province in western China.The visit marked several firsts for Zeng,including leaving her hometown,riding a train and taking a subway.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co-supported by the National Natural Science Foundation of China(grant No.41472082)the National Key Research and Development Program of China (grant No.2016YFC0601001)+2 种基金the program of China Geological Survey(grant No.12120115068901)the National Stratigraphic committee of ChinaGlobal Geopark of Shennongjia(Shennongjia National Park)
文摘Objective Spherical micro-particles are often preserved in Precambrian sedimentary rocks. Finnish and Chinese scholars have previously discovered carbonaceous, siliceous or ferruginous spherules of out-space origin in the 1.6 Ga and 1.4 Ga sequence, respectively. The presence of spherules can record possible cosmic impact events. Also, cosmic spherules provide important information on the evolution of planets from outer space.
文摘The world's first woman president was Isabel Martinez de Peron(b.1931).In July,1974,Juan Domingo Peron,the president of Argentina,died,leaving his wife Isabel Martinez de Peron,then the vice-president,to succeed him according to the cons stitution.
文摘Zeng Xiaolan called her April trip to Beijing"mind-blowing"."The Forbidden City is so big and magnificent.I'd only seen it on TV before,"said the 14-year-old from Qinghai,a sparsely populated province in western China.The visit marked several firsts for Zeng,including leaving her hometown,riding a train and taking a subway.
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.
