Geochronological and Geochemical Evidence for the Sedimentary Transformation from the Banxi Period to Nanhua Glacial Period

Objective There has been considerable debate about the definition of the lower boundary of Nanhua System by far.One definition is based on sedimentary sequence of different stages of basin evolution,focusing on whether deposits of the Banxi Period should be classified as Nanhua System.Another is the onset time of Nanhua glacial period.

The change of the cationic peroxidase in the leaves at the fertile transformation period in Nongken 58s

Nongken 58s is a type of photoperiod sensitivegenie male sterile rice which gives rice to malesterility when illuminated time is longer than13.75 h/d.The photoperiod sensitive stagesare from the differentiation of primary branchprimordum(Ⅱ)in young ears to fullness ofcontents of the pollen(Ⅶ).The changes ofactivity and isoenzymes in cation peroxidase atph0toperiod sensitive stages and the relation-ship between this enzyme and feritility of rice

Periodicities in the emplacement of large igneous provinces through the Phanerozoic:Relations to ocean chemistry and marine biodiversity evolution

Large igneous provinces （LIPs） are considered a relevant cause for mass extinctions of marine life throughout Earth＇s history. Their flood basalts and associated intrusions can cause significant release of SO4 and CO2 and consequently, cause major environmental disruptions. Here, we reconstruct the long-term periodic pattern of LIP emplacement and its impact on ocean chemistry and biodiversity from δ34Ssulfate of the last 520 Ma under particular consideration of the preservation limits of LIP records. A combination of cross-wavelet and other time-series analysis methods has been applied to quantify a potential chain of linkage between LIP emplacement periodicity, geochemical changes and the Phanerozoic marine genera record. We suggest a mantle plume cyclicity represented by LIP volumes （V） of V= （350-770） × 103km3sin（27πt/ 170 Ma）＋ （300-650）× 103 km3 sin（2πt/64.5 Ma ＋ 2.3） for t= time in Ma. A shift from the 64.5 Ma to a weaker -28-35 Ma LIP cyclicity during the Jurassic contributes together with probably independent changes in the marine sulfur cycle to less ocean anoxia, and a general stabilization of ocean chemistry and increasing marine biodiversity throughout the last -135 Ma. The LIP cycle pattern is coherent with marine biodiversity fluctuations corresponding to a reduction of marine biodiversity of -120 genera/Ma at 600 x 103 km3 LIP eruption volume. The 62-65 Ma LIP cycle pattern as well as excursion in -34Ssulfate and marine genera reduction suggest a not-vet identified found LIP event at - 440-450 Ma.

世界进入新的动荡变革期与新时代的中国

The world is undergoing profound changes unseen in a century.As the changes are accelerating,their impact is intensifying.International politics is experiencing a return to realism,and the rise of hegemonic power is antagonizing global relations.Globalization has encountered setbacks,and world economic growth is contracting.The international order is tumbling and is facing reconstruction.Nontraditional security threats have become more diverse.Great power conflicts are looming large.The 20th National Congress of the Communist Party of China has drawn a magnificent blueprint for constructing Chinese-style modernization.China,a responsible power in its historic rise,will be a stabilizing force in a turbulent world and a constructive force for global transformation.China provides stability,positive energy,great global peace,and development opportunities.

A Property of Continuous Mapping from a Sphere to the Euclidean Space and Its Applications

In this paper, we study the property of continuous mappings from a sphere to the Euclidean space. By using the theory of the periodic transformation in algebraic topology, we obtain a generalized Borsuk-Ulam theorem and then give some applications of the theorem.