Changes in the marine productivity and sedimentary environment since the last deglaciation in the Ross Sea are presented in this paper.Opal has replaced calcium carbonate as the major biogenic component and has a sign...Changes in the marine productivity and sedimentary environment since the last deglaciation in the Ross Sea are presented in this paper.Opal has replaced calcium carbonate as the major biogenic component and has a significantly positive correlation with total organic carbon(TOC),which indicates that siliceous phytoplankton controlled the absorption and release of carbon by the biological pump and was the main producer of marine organic matter.Using the AMS 14C age framework,foraminiferal fossils and redox sensitive elements(RSEs),we found that both the sedimentary environment and marine productivity changed clearly in^11 cal ka BP,which is more likely related with the melting and retreat of the Ross Ice Shelf.In addition,the increase of marine productivity promoted the sinking of more organic-matter to the seabed.A large proportion of oxygen in the bottom water body was consumed and more carbon dioxide was produced during the decomposition of organic matter,making the bottom water body more soluble to calcium carbonate.展开更多
随着信息化技术的不断深化应用,数据安全和抗篡改愈发重要。在各类信息系统建设中,不论是科学研究的相关数据,还是设备管理的设备履历数据,都需要数据真实可信,而现实中经常出现需要数据时临时补造数据的情况。为防止这种问题,需要设计...随着信息化技术的不断深化应用,数据安全和抗篡改愈发重要。在各类信息系统建设中,不论是科学研究的相关数据,还是设备管理的设备履历数据,都需要数据真实可信,而现实中经常出现需要数据时临时补造数据的情况。为防止这种问题,需要设计一个低成本运行,对数据无入侵,由中心化组织维护,但抗中心化篡改的技术方案。基于区块链和工作量证明,设计一个最小可支持单机系统运行的抗篡改技术TDBBP(technology of tamper detection based on blockchain and pow),通过链式哈希块关联各数据日志块,通过工作量证明配合审计,使得稍长时间的数据日志块没有足够时间伪造重建,从而提供抗篡改能力。展开更多
基金Supported by the Public Science and Technology Research Funds Projects of Ocean(No.201105003-2)the Chinese Polar Environment Comprehensive Investigation&Assessment Programs(No.CHINARE2016-01-02)。
文摘Changes in the marine productivity and sedimentary environment since the last deglaciation in the Ross Sea are presented in this paper.Opal has replaced calcium carbonate as the major biogenic component and has a significantly positive correlation with total organic carbon(TOC),which indicates that siliceous phytoplankton controlled the absorption and release of carbon by the biological pump and was the main producer of marine organic matter.Using the AMS 14C age framework,foraminiferal fossils and redox sensitive elements(RSEs),we found that both the sedimentary environment and marine productivity changed clearly in^11 cal ka BP,which is more likely related with the melting and retreat of the Ross Ice Shelf.In addition,the increase of marine productivity promoted the sinking of more organic-matter to the seabed.A large proportion of oxygen in the bottom water body was consumed and more carbon dioxide was produced during the decomposition of organic matter,making the bottom water body more soluble to calcium carbonate.
文摘随着信息化技术的不断深化应用,数据安全和抗篡改愈发重要。在各类信息系统建设中,不论是科学研究的相关数据,还是设备管理的设备履历数据,都需要数据真实可信,而现实中经常出现需要数据时临时补造数据的情况。为防止这种问题,需要设计一个低成本运行,对数据无入侵,由中心化组织维护,但抗中心化篡改的技术方案。基于区块链和工作量证明,设计一个最小可支持单机系统运行的抗篡改技术TDBBP(technology of tamper detection based on blockchain and pow),通过链式哈希块关联各数据日志块,通过工作量证明配合审计,使得稍长时间的数据日志块没有足够时间伪造重建,从而提供抗篡改能力。
