The Lomagundi-Jatuli Event(LJE)refers to the significant positive carbon isotope excursion in seawater constituents that occurred immediately after the increase in atmospheric oxygen content during the Paleoproterozoi...The Lomagundi-Jatuli Event(LJE)refers to the significant positive carbon isotope excursion in seawater constituents that occurred immediately after the increase in atmospheric oxygen content during the Paleoproterozoic(2.22-2.06 Ga).Theδ^(13)C values of 46 dolostone samples collected from the Paleoproterozoic Yongjingshao Formation varied in the range of 0.05‰-4.95‰(V-PDB;maximum:4.95‰)in this study,which may be related to the multicellular eukaryotes in the Liangshan Formation in the Yimen Group.They are much higher than theδ^(13)C values of marine carbonates(-1.16‰on average).Theδ^(13)C values of other formations in the Paleoproterozoic Yimen Group are negative.The notable positive carbon isotope anomalies of the Yongjingshao Formation indicate the response to the LJE at the southwestern margin of the Yangtze Block,which is reported for the first time.Furthermore,they are comparable to theδ^(13)C values of carbonates in the Dashiling Formation of the Hutuo Group in the Wutaishan area in the North China Craton,the Wuzhiling Formation of the Songshan Group in the Xiong'er area,Henan Province,and the Dashiqiao Formation of the Liaohe Group in the Guanmenshan area,Liaoning Province.Therefore,it can be further concluded that the LJE is a global event.This study reveals that LJE occurred in Central Yunnan at 2.15-2.10 Ga,lasting for about 50 Ma.The macro-columnar,bean-shaped,and microfilament fossils and reticular ultramicrofossils of multicellular eukaryotes in this period were discovered in the Liangshan Formation of the Yimen Group.They are the direct cause for the LJE and are also the oldest paleontological fossils ever found.The major events successively occurring in the early stage of the Earth include the Great Oxygenation Event(first occurrence),the global Superiortype banded iron formations(BIFs),the Huronian glaciation,the Great Oxygenation Event(second occurrence),the explosion of multicellular eukaryotes,the positive carbon isotope excursion,and the global anoxic and selenium-rich sedimentary event.The authors think that the North China Craton and the Yangtze Craton were possibly in different tectonic locations of the same continental block during the Proterozoic.展开更多
目的探讨粘着性棉布伸缩包带固定法预防经外周静脉置入中心静脉导管(peripherally inserted central catheter,PICC)脱出的效果。方法将82例PICC置管患者按简单数字表法随机分为观察组和对照组,每组各41例,对照组患者PICC固定采用普通3...目的探讨粘着性棉布伸缩包带固定法预防经外周静脉置入中心静脉导管(peripherally inserted central catheter,PICC)脱出的效果。方法将82例PICC置管患者按简单数字表法随机分为观察组和对照组,每组各41例,对照组患者PICC固定采用普通3M胶布固定法,观察组患者PICC固定采用粘着性棉布伸缩包带固定法。比较两组患者PICC置管期间导管脱出率及脱出程度。结果两组患者PICC置管期间导管脱出率及脱出程度比较,均P<0.01,差异具有统计学意义,观察组患者PICC置管期间导管脱出率及程度明显低于和轻于对照组。结论采用粘着性棉布伸缩包带固定法固定PICC效果明显优于采用普通3M胶布固定法,其能有效降低PICC置管期间导管脱出发生率。展开更多
In this study, argon and nitrogen were used as the discharge gases in radio-frequency （RF： 13.56 MHz） powered dielectric barrier atmospheric plasma. It was noticed that in single dielectric barrier discharge （DBD...In this study, argon and nitrogen were used as the discharge gases in radio-frequency （RF： 13.56 MHz） powered dielectric barrier atmospheric plasma. It was noticed that in single dielectric barrier discharge （DBD） with nitrogen as the discharge gas, or in argon plasma with a high applied power, micro-filament channels were easily formed. The channels in these two kinds of discharge were both constrictive on the bare metallic electrode and expansive on the opposite electrode covered with a quartz layer. The number of micro-channels was increased along with the input power, which caused the change in the I-V curve shape, i.e., the current kept increasing and the voltage fluctuated within a confined range. With double dielectric layers, however, no micro-channels appeared in the ICCD images, and the I-V curve demonstrated a totally different shape. It was assumed that micro-filaments exhibited a restraining effect on the discharge voltage. The mechanism of this restraining effect was explored in this work.展开更多
In this context,we firstly synthesized a novel nitrogen-doped multiporous carbon material from renewable biological cells through a facile chemical activation with K;CO;.After sulfur impregnation,the carbon/sulfur com...In this context,we firstly synthesized a novel nitrogen-doped multiporous carbon material from renewable biological cells through a facile chemical activation with K;CO;.After sulfur impregnation,the carbon/sulfur composite achieved a sulfur content of about 67 wt%.The C/S composite as the cathode of lithium-sulfur batteries exhibited a discharge capacity of 1410 mAh/g and good capacity retention of912 mAh/g at 0.1C.These outstanding results were attributed to the synergy effect of microporous carbon and natural doping nitrogen atoms.We believe that the facile approach for the synthesis of nitrogen-doped multiporous carbon from the low-cost and sustainable biological resources will not only be applied in lithium-sulfur batteries,but also in other electrode materials.展开更多
基金financially supported by the project entitled 1∶50000 Regional Geological Survey of Samaki,Yinmin,Guicheng,and Shugu Sheets in Yunnan Province(D201905)organized by the Land and Resources Department of Yunnan ProvinceTraining Object Project of technological innovation talents in Yunnan Province(202205AD160073)+2 种基金the project entitled“1∶50000 Regional Geological Survey of Dazhuang,Fabiao,Ditu,and Dianzhong Sheets in Yunnan Province”(S53A00722001048-007)“Joint Foundation Project between Yunnan Science and Technology Department and Yunnan University”(CY21624103)the project entitled“Area Summary and Service Product Development of Regional Geological Surveys in Yunnan Province”initiated by the China Geological Survey(121201102000150012-02)。
文摘The Lomagundi-Jatuli Event(LJE)refers to the significant positive carbon isotope excursion in seawater constituents that occurred immediately after the increase in atmospheric oxygen content during the Paleoproterozoic(2.22-2.06 Ga).Theδ^(13)C values of 46 dolostone samples collected from the Paleoproterozoic Yongjingshao Formation varied in the range of 0.05‰-4.95‰(V-PDB;maximum:4.95‰)in this study,which may be related to the multicellular eukaryotes in the Liangshan Formation in the Yimen Group.They are much higher than theδ^(13)C values of marine carbonates(-1.16‰on average).Theδ^(13)C values of other formations in the Paleoproterozoic Yimen Group are negative.The notable positive carbon isotope anomalies of the Yongjingshao Formation indicate the response to the LJE at the southwestern margin of the Yangtze Block,which is reported for the first time.Furthermore,they are comparable to theδ^(13)C values of carbonates in the Dashiling Formation of the Hutuo Group in the Wutaishan area in the North China Craton,the Wuzhiling Formation of the Songshan Group in the Xiong'er area,Henan Province,and the Dashiqiao Formation of the Liaohe Group in the Guanmenshan area,Liaoning Province.Therefore,it can be further concluded that the LJE is a global event.This study reveals that LJE occurred in Central Yunnan at 2.15-2.10 Ga,lasting for about 50 Ma.The macro-columnar,bean-shaped,and microfilament fossils and reticular ultramicrofossils of multicellular eukaryotes in this period were discovered in the Liangshan Formation of the Yimen Group.They are the direct cause for the LJE and are also the oldest paleontological fossils ever found.The major events successively occurring in the early stage of the Earth include the Great Oxygenation Event(first occurrence),the global Superiortype banded iron formations(BIFs),the Huronian glaciation,the Great Oxygenation Event(second occurrence),the explosion of multicellular eukaryotes,the positive carbon isotope excursion,and the global anoxic and selenium-rich sedimentary event.The authors think that the North China Craton and the Yangtze Craton were possibly in different tectonic locations of the same continental block during the Proterozoic.
文摘目的探讨粘着性棉布伸缩包带固定法预防经外周静脉置入中心静脉导管(peripherally inserted central catheter,PICC)脱出的效果。方法将82例PICC置管患者按简单数字表法随机分为观察组和对照组,每组各41例,对照组患者PICC固定采用普通3M胶布固定法,观察组患者PICC固定采用粘着性棉布伸缩包带固定法。比较两组患者PICC置管期间导管脱出率及脱出程度。结果两组患者PICC置管期间导管脱出率及脱出程度比较,均P<0.01,差异具有统计学意义,观察组患者PICC置管期间导管脱出率及程度明显低于和轻于对照组。结论采用粘着性棉布伸缩包带固定法固定PICC效果明显优于采用普通3M胶布固定法,其能有效降低PICC置管期间导管脱出发生率。
基金supported financially by National Natural Science Foundation of China (No.11175024)Beijing Natural Science Foundation(Nos.1112012), 2011BAD24B01+1 种基金Scientific Research Common Program of Beijing Municipal Commission of Education of China (KM201110015008, KM 201010015005)Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality (PHR20110516)
文摘In this study, argon and nitrogen were used as the discharge gases in radio-frequency （RF： 13.56 MHz） powered dielectric barrier atmospheric plasma. It was noticed that in single dielectric barrier discharge （DBD） with nitrogen as the discharge gas, or in argon plasma with a high applied power, micro-filament channels were easily formed. The channels in these two kinds of discharge were both constrictive on the bare metallic electrode and expansive on the opposite electrode covered with a quartz layer. The number of micro-channels was increased along with the input power, which caused the change in the I-V curve shape, i.e., the current kept increasing and the voltage fluctuated within a confined range. With double dielectric layers, however, no micro-channels appeared in the ICCD images, and the I-V curve demonstrated a totally different shape. It was assumed that micro-filaments exhibited a restraining effect on the discharge voltage. The mechanism of this restraining effect was explored in this work.
基金the National Natural Science Foundation of China(Nos.61371021,61527818)Shanghai Municipal Education Commission(Peak Discipline Construction Program)Shanghai Education Commission Innovation Project(No.14YZ016)
文摘In this context,we firstly synthesized a novel nitrogen-doped multiporous carbon material from renewable biological cells through a facile chemical activation with K;CO;.After sulfur impregnation,the carbon/sulfur composite achieved a sulfur content of about 67 wt%.The C/S composite as the cathode of lithium-sulfur batteries exhibited a discharge capacity of 1410 mAh/g and good capacity retention of912 mAh/g at 0.1C.These outstanding results were attributed to the synergy effect of microporous carbon and natural doping nitrogen atoms.We believe that the facile approach for the synthesis of nitrogen-doped multiporous carbon from the low-cost and sustainable biological resources will not only be applied in lithium-sulfur batteries,but also in other electrode materials.
