The wavelet transform method for high-quality time-frequency analysis is applied to sets of observations of relative sunspot numbers and stellar chromosphere fluxes of 10 Sun-like stars. Wavelet analysis of solar data...The wavelet transform method for high-quality time-frequency analysis is applied to sets of observations of relative sunspot numbers and stellar chromosphere fluxes of 10 Sun-like stars. Wavelet analysis of solar data shows that in a certain interval of time there are several cycles of activity with pe- riods of duration which vary considerably from each other： from quasi-biennial cycles to lO0-yr cycles. Cyclic activity was detected in almost all Sun-like stars that we examined, even those that previously were not considered as stars with cyclic activity according to analysis using a Scargle periodogram. The durations of solar and stellar cycles significantly change during the observation period.展开更多
The Snowball Earth hypothesis suggests that the sea water had totally been kept frozen for millions of years in Neoproterozoic glaciation, followed by a rapid and catastrophic deglaciation resulting from the elevated ...The Snowball Earth hypothesis suggests that the sea water had totally been kept frozen for millions of years in Neoproterozoic glaciation, followed by a rapid and catastrophic deglaciation resulting from the elevated concentration of atmospheric CO〉 However, the sedimen- tary records are not consistent with the Snowball Earth hypothesis. The Nantuo Formation in Three Gorges area is composed of diamictites, sandstones and siltstones. The geochronology and the unconformity with underlying Liantuo Formation indicate that the Nantuo Formation in Three Gorges area may be the partial record （i.e., the final stage） of the Nantuo glaciation. Our studies on sedimentary successions of the Nantuo Formation convince the stepwise transition from the Cryogenia icehouse to the Ediacaran greenhouse, in which multiple glacier advance- retreat cycles rather than a catastrophic termination could be identified.展开更多
This erratum pertains to the article by Wang et al.(2023)titled“Unusual evolution of the multiple eyewall cycles in Super Typhoon Hinnamnor(2022).”This notice corrects the following inappropriate expressions in the ...This erratum pertains to the article by Wang et al.(2023)titled“Unusual evolution of the multiple eyewall cycles in Super Typhoon Hinnamnor(2022).”This notice corrects the following inappropriate expressions in the original publication.(1)“Central Weather Bureau(CWB)in Taiwan region”should be“Weather Bureau in Taiwan(TWB)of China.”展开更多
This paper introduces the high-speed electrical multiple unit （EMO） life cycle, including the design, manufacturing, testing, and maintenance stages. It also presents the train control and monitoring system （TCMS）...This paper introduces the high-speed electrical multiple unit （EMO） life cycle, including the design, manufacturing, testing, and maintenance stages. It also presents the train control and monitoring system （TCMS） software development platform, the TCMS testing and verification bench, the EMU driving simulation platform, and the EMU remote data transmittal and maintenance platform. All these platforms and benches combined together make up the EMU life cycle cost （LCC） system. Each platform facilitates EMU LCC management and is an important part of the system.展开更多
The nonlinear oscillatory phenomenon has been observed in the system of immune response, which corresponds to the limit cycles in the mathematical models. We prove that the system simulating an immune response studied...The nonlinear oscillatory phenomenon has been observed in the system of immune response, which corresponds to the limit cycles in the mathematical models. We prove that the system simulating an immune response studied by Huang has at least three limit cycles in the system. The conditions for the multiple limit cycles are useful in analyzing the nonlinear oscillation in immune response.展开更多
Cycle multiplicity of a graph G is the maximum number of edge disjoint cycles in G. In this paper, we determine the cycle multiplicity of and then obtain the formula of cycle multiplicity of total graph of complete bi...Cycle multiplicity of a graph G is the maximum number of edge disjoint cycles in G. In this paper, we determine the cycle multiplicity of and then obtain the formula of cycle multiplicity of total graph of complete bipartite graph, this generalizes the result for, which is given by M.M. Akbar Ali in [1].展开更多
In this paper, we obtain the exact computation formulae to determine the stability of a multiple limit cycle with the third or fourth order degenerations. We employ the method of computing the expansion of the Poincar...In this paper, we obtain the exact computation formulae to determine the stability of a multiple limit cycle with the third or fourth order degenerations. We employ the method of computing the expansion of the Poincar′e map around the closed orbit using 'normal bundle' coordinates parameterized by time variable in a neighborhood of the closed orbit. An example is given to show the feasibility of our results.展开更多
In this paper we consider a kind of predator-prey model named Holling-Tanner model.Firstly,we prove all solutions of this model to be bounded from above.Secondly,we find a positive invariant set of the model,and prove...In this paper we consider a kind of predator-prey model named Holling-Tanner model.Firstly,we prove all solutions of this model to be bounded from above.Secondly,we find a positive invariant set of the model,and prove the existence of stable limit cycle in this invariant set by Poincaré-Bendixson theorem for the unstable equilibrium.Thirdly,we get the region of parameters in which the corresponding stable equilibrium are also globally asymptotically stable.Lastly,we give a bifurcation diagram and illustration with two limit cycles for special parameters through numerical simulation.By our knowledge,the invariant set constructed in this paper is better than that in the book written by Murray.展开更多
In this paper, the influence of sampling intervals on the chattering in sliding mode （SM） control systems is considered. The describing function （DF） approach is employed to analyze the chattering characteristics ...In this paper, the influence of sampling intervals on the chattering in sliding mode （SM） control systems is considered. The describing function （DF） approach is employed to analyze the chattering characteristics in the sampling SM control. By the DF calculations and limit cycle existence conditions, an unstable limit cycle and two stable limit cycles are found in the SM control system. The frequencies and amplitudes of the two limit cycles can also be estimated by graphical calculations. The estimation accuracy of chattering parameters is evaluated by the simulations. The results of simulations show that the system could converge to a large and a small limit cycle from different initial conditions.展开更多
Loquat orchard location was the main driver of microbial communities and loquat fruit quality.The average fruit weight was correlated with theɑ-andβ-diversity of bacteria and protists.Soil bacterial and protistan co...Loquat orchard location was the main driver of microbial communities and loquat fruit quality.The average fruit weight was correlated with theɑ-andβ-diversity of bacteria and protists.Soil bacterial and protistan communities drove the multiple nutrient cycling.The role of the soil microbiome in fruit quality within loquat orchards remains largely unknown.In this study,we collected soil samples from various loquat orchards in Ningbo,Zhejiang Province,China and investigated bacterial,fungal,and protist communities.The results showed that soil physicochemical conditions,the microbial community,and loquat fruit quality were significantly related to orchard location but unrelated to cultivation time and fertilization.The heterogeneity of the bacterial community was driven by soil pH,available phosphorus,and available potassium(AK).The fungal community was driven by soil electrical conductivity and AK.The protist community was driven by soil dissolved organic nitrogen and AK.The average fruit weight was significantly correlated with theɑ-andβ-diversity of bacteria and protists as well as the soil multiple nutrient cycling index.Several microbial phyla were related to average fruit weight,while other fruit quality indicators could not be explained by the soil microbiome.Our results reveal that bacterial and protist communities in loquat orchards drive the cycling of multiple nutrients that are related to fruit weight.These insights shed light on the relationship among the soil microbiome,nutrient cycling,and fruit quality,offering valuable scientific guidance for orchard management practices.展开更多
文摘The wavelet transform method for high-quality time-frequency analysis is applied to sets of observations of relative sunspot numbers and stellar chromosphere fluxes of 10 Sun-like stars. Wavelet analysis of solar data shows that in a certain interval of time there are several cycles of activity with pe- riods of duration which vary considerably from each other： from quasi-biennial cycles to lO0-yr cycles. Cyclic activity was detected in almost all Sun-like stars that we examined, even those that previously were not considered as stars with cyclic activity according to analysis using a Scargle periodogram. The durations of solar and stellar cycles significantly change during the observation period.
基金Acknowledgements We thank so much to Prof. Shucheng Xie and two anonymous reviewers for their great constructive comments and corrections to our manuscript. This research was financially supported by the National Basic Research Program of China （Nos. 2011CB808805 and 2009CB21950605）, the National Natural Science Foundation of China （Grant Nos. 41172102 and 40772073）, SinoPec project （GO800-O6-ZS-319） and 111 Project （B08030）.
文摘The Snowball Earth hypothesis suggests that the sea water had totally been kept frozen for millions of years in Neoproterozoic glaciation, followed by a rapid and catastrophic deglaciation resulting from the elevated concentration of atmospheric CO〉 However, the sedimen- tary records are not consistent with the Snowball Earth hypothesis. The Nantuo Formation in Three Gorges area is composed of diamictites, sandstones and siltstones. The geochronology and the unconformity with underlying Liantuo Formation indicate that the Nantuo Formation in Three Gorges area may be the partial record （i.e., the final stage） of the Nantuo glaciation. Our studies on sedimentary successions of the Nantuo Formation convince the stepwise transition from the Cryogenia icehouse to the Ediacaran greenhouse, in which multiple glacier advance- retreat cycles rather than a catastrophic termination could be identified.
文摘This erratum pertains to the article by Wang et al.(2023)titled“Unusual evolution of the multiple eyewall cycles in Super Typhoon Hinnamnor(2022).”This notice corrects the following inappropriate expressions in the original publication.(1)“Central Weather Bureau(CWB)in Taiwan region”should be“Weather Bureau in Taiwan(TWB)of China.”
文摘This paper introduces the high-speed electrical multiple unit （EMO） life cycle, including the design, manufacturing, testing, and maintenance stages. It also presents the train control and monitoring system （TCMS） software development platform, the TCMS testing and verification bench, the EMU driving simulation platform, and the EMU remote data transmittal and maintenance platform. All these platforms and benches combined together make up the EMU life cycle cost （LCC） system. Each platform facilitates EMU LCC management and is an important part of the system.
文摘The nonlinear oscillatory phenomenon has been observed in the system of immune response, which corresponds to the limit cycles in the mathematical models. We prove that the system simulating an immune response studied by Huang has at least three limit cycles in the system. The conditions for the multiple limit cycles are useful in analyzing the nonlinear oscillation in immune response.
文摘Cycle multiplicity of a graph G is the maximum number of edge disjoint cycles in G. In this paper, we determine the cycle multiplicity of and then obtain the formula of cycle multiplicity of total graph of complete bipartite graph, this generalizes the result for, which is given by M.M. Akbar Ali in [1].
基金Supported by the Fundamental Research Funds for the Central Universities
文摘In this paper, we obtain the exact computation formulae to determine the stability of a multiple limit cycle with the third or fourth order degenerations. We employ the method of computing the expansion of the Poincar′e map around the closed orbit using 'normal bundle' coordinates parameterized by time variable in a neighborhood of the closed orbit. An example is given to show the feasibility of our results.
基金supported by the National Natural Science Foundation of China(Grant No.62227810)。
文摘In this paper we consider a kind of predator-prey model named Holling-Tanner model.Firstly,we prove all solutions of this model to be bounded from above.Secondly,we find a positive invariant set of the model,and prove the existence of stable limit cycle in this invariant set by Poincaré-Bendixson theorem for the unstable equilibrium.Thirdly,we get the region of parameters in which the corresponding stable equilibrium are also globally asymptotically stable.Lastly,we give a bifurcation diagram and illustration with two limit cycles for special parameters through numerical simulation.By our knowledge,the invariant set constructed in this paper is better than that in the book written by Murray.
基金supported by Industrial Research Projects in department of education of Shaanxi province(2014K05-29)Science Research Projects in department of education of Shaanxi province(14JK1669,14JF028)
文摘In this paper, the influence of sampling intervals on the chattering in sliding mode （SM） control systems is considered. The describing function （DF） approach is employed to analyze the chattering characteristics in the sampling SM control. By the DF calculations and limit cycle existence conditions, an unstable limit cycle and two stable limit cycles are found in the SM control system. The frequencies and amplitudes of the two limit cycles can also be estimated by graphical calculations. The estimation accuracy of chattering parameters is evaluated by the simulations. The results of simulations show that the system could converge to a large and a small limit cycle from different initial conditions.
基金supported by the Ningbo Science and Technology Bureau(Grant No.2021S013)Agricultural Science and Technology Project of the Xiangshan Science and Technology Bureau(Grant No.2022C1018).
文摘Loquat orchard location was the main driver of microbial communities and loquat fruit quality.The average fruit weight was correlated with theɑ-andβ-diversity of bacteria and protists.Soil bacterial and protistan communities drove the multiple nutrient cycling.The role of the soil microbiome in fruit quality within loquat orchards remains largely unknown.In this study,we collected soil samples from various loquat orchards in Ningbo,Zhejiang Province,China and investigated bacterial,fungal,and protist communities.The results showed that soil physicochemical conditions,the microbial community,and loquat fruit quality were significantly related to orchard location but unrelated to cultivation time and fertilization.The heterogeneity of the bacterial community was driven by soil pH,available phosphorus,and available potassium(AK).The fungal community was driven by soil electrical conductivity and AK.The protist community was driven by soil dissolved organic nitrogen and AK.The average fruit weight was significantly correlated with theɑ-andβ-diversity of bacteria and protists as well as the soil multiple nutrient cycling index.Several microbial phyla were related to average fruit weight,while other fruit quality indicators could not be explained by the soil microbiome.Our results reveal that bacterial and protist communities in loquat orchards drive the cycling of multiple nutrients that are related to fruit weight.These insights shed light on the relationship among the soil microbiome,nutrient cycling,and fruit quality,offering valuable scientific guidance for orchard management practices.
