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New perspectives on deep carbon cycling

Science China Earth Sciences 2024年第8期67卷 2411-2422页

作者： weidong sun Center of Deep Sea Research Key Laboratory of Ocean Observation and ForecastingInstitute of OceanologyChinese Academy of SciencesQingdao 266071China Laoshan Laboratory Qingdao 266237China University of Chinese Academy of Sciences Beijing 100049China

The proto-atmosphere serves as a crucial starting point for the carbon *** based on atmospheric data from Mars and Venus suggest that Earth's proto-atmosphere contained>110 bar of CO_(2)and>2.6 bar of *** protoatmosphere had over 1000 bar of water vapor during the magma ocean stage,assuming the proto-ocean had a volume of two oceans of *** this stage both water and carbon dioxide were in a supercritical state at the magma-atmosphere *** serpentinization reactions occurred due to rock-water interaction,producing abundant ***,nitrogen is reduced to ammonia,and carbon dioxide to methane,forming carbonate *** proto-atmosphere dominated by methane,ammonia,and hydrogen formed a significant amount of amino acids through *** process is essential not only to the origin of life,but also to the early carbon-nitrogen cycle on *** the Hadean eon,a large amount of CO_(2)was sequestered as carbonate and organic ***,it mainly entered the deep mantle through mantle overturn or *** the mantle transition zone,carbonate undergoes“Redox freezing”,where carbonate is reduced to diamond through oxidation of ferrous iron in the *** the lower mantle,Fe^(2+)undergoes disproportionation reactions,forming Fe^(3+)and metallic *** these,Fe^(3+)mainly resides in bridgmanite,thereby increasing the oxygen fugacity of the lower mantle,while metallic iron falls to the Earth's *** distribution of carbon in the mantle is crucial for deep carbon *** density curves of diamond and mantle peridotite melt intersect at the bottom of the mantle transition zone(about 660 km).This density crossover leads to the accumulation of diamond during the magma ocean *** materials such as subducting slabs enter the lower mantle,compensatory upwelling of lower mantle material *** enters the upper mantle,decomposes,releasing Fe^(3+)ions and oxidizes diamond

关键词： Carbon cycling Proto-atmosphere Amino acids Subduction initiation Passive margin subduction Atmospheric carbon dioxide

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The influence of silica on reaction rates and molecular hydrogen(H_(2))generation during olivine hydrothermal alteration

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Science China Earth Sciences 2024年第1期67卷 222-233页

作者： Ruifang HUANG weidong sun Xing DING Yusheng ZHAO Yibing LI Xiuqi SHANG CAS Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China SUSTech Academy for Advanced Interdisciplinary Studies Southern University of Science and TechnologyShenzhen 518055China Center of Deep Sea Research Institute of OceanologyChinese Academy of SciencesQingdao 266071China State Key Laboratory of Isotope Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Institue of Geology Chinese Academy of Geological SciencesBeijing 100037China

Hydrothermal alteration of olivine greatly influences geodynamics and the recycling of volatiles(such as water and carbon)in subduction *** is an important component of geological fluids,and its influence on the hydrothermal alteration of olivine remains poorly *** this study,we performed experiments at 300–515℃ and 3.0 kbar(1 bar=10^(5)Pa)by reacting well homogenized mixtures of olivine and silica powders with saline solutions(0.5 mol L^(−1)NaCl).Silica greatly influences the reaction pathways,reaction rates,and molecular hydrogen(H_(2))formation during olivine hydrothermal *** experiments at 300℃ and 3.0 kbar with mixtures of olivine and 10 wt%silica,olivine was replaced by serpentine and *** proportions of serpentine and talc were determined according to standard curves based on infrared spectroscopy *** 6.5%serpentine and 12%talc were produced after an experimental duration of 7 days,which had no change after a longer period(14 days).Compared to the kinetics in silica-free systems,the rates of olivine hydrothermal alteration in experiments with 10 wt%silica are much *** overall reaction is:4.5Forsterite+5.5SiO_(2),aq+4H_(2)O=Serpentine+*** the addition of more silica(20 wt%and 40 wt%),olivine was transformed into *** rates of reaction were much faster,e.g.,for experiments with olivine and 20 wt%silica,43%of talc was produced after 14 days,which increased to 77%for experiments with 40 wt%silica over the same *** overall reaction is:3Forsterite+5SiO_(2),aq+2H_(2)O=*** experiments at 400–505℃ and 3.0 kbar,the promoting effect of silica on olivine hydrothermal alteration was also observed,which is closely associated with a decrease in Gibbs free energies of olivine hydrothermal *** 300℃ and 3.0 kbar,silica decreased H_(2)formed during olivine hydrothermal alteration by around an order of magnitude,resulting in an increase in oxygen *** on measured H_(2),we calibrated ox

关键词： Olivine hydrothermal alteration Silica Serpentinization Hydrogen Serpentine

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近海海底管道阴极保护有效性的评估方法及应用

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腐蚀与防护 2024年第1期45卷 93-98页

作者：孙伟栋管网集团(徐州)管道检验检测有限公司徐州221008

以某在役海底输油管道牺牲阳极阴极保护系统为应用对象,采用室内试验结合数值模拟方法,及海底管道电位实测和牺牲阳极取样测试等方法,获得了海底管道保护电位水平并预估了牺牲阳极寿命。结果表明:牺牲阳极在所处海域的电化学行为与初始... 详细信息

以某在役海底输油管道牺牲阳极阴极保护系统为应用对象,采用室内试验结合数值模拟方法,及海底管道电位实测和牺牲阳极取样测试等方法,获得了海底管道保护电位水平并预估了牺牲阳极寿命。结果表明:牺牲阳极在所处海域的电化学行为与初始设计选值稍有偏差,结合数值模拟结果,牺牲阳极寿命能够满足初始设计要求(35 a),且寿命期内海底管道保护电位达标,管道处于有效保护状态。数值模拟方法结合实际检测对评估海底管道牺牲阳极阴极保护状况具有较好的一致性和互补性。

关键词：海底管道牺牲阳极阴极保护寿命电位分布数值模拟

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SAR影像与对抗学习融合下的可见光影像云雾去除

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测绘科学 2024年第4期49卷 92-102页

作者：徐妍周杰赵伶俐孙维东武汉大学遥感信息工程学院武汉430000 湖北移动设计院武汉430000 自然资源部城市国土资源监测与仿真重点实验室武汉430000 武汉大学测绘遥感信息工程国家重点实验室武汉430000

针对光学遥感影像经常受到云雾遮挡、干扰解译,使得数据利用率低的问题,该文利用SAR影像全天时全天候的特性,提出了一套“雷达-光学”的影像转换算法,以SAR影像为输入,利用对抗网络结合深度学习强大的非线性映射能力以及对抗学习博弈式... 详细信息

针对光学遥感影像经常受到云雾遮挡、干扰解译,使得数据利用率低的问题,该文利用SAR影像全天时全天候的特性,提出了一套“雷达-光学”的影像转换算法,以SAR影像为输入,利用对抗网络结合深度学习强大的非线性映射能力以及对抗学习博弈式学习任意数据分布的特点,实现通过云覆盖区域的SAR影像直接生成相应的无云伪可见光影像。实验表明,该方法对于薄云、厚云、大范围云雾的去除效果均比较好,能够在很大程度上提升光学遥感影像的可用性。

关键词：合成孔径雷达对抗学习云雾去除

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腹腔热灌注化疗联合肿瘤细胞减灭术对卵巢癌患者的治疗效果

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首都食品与医药 2024年第7期31卷 49-51页

作者：孙卫东河北省滦南县医院河北唐山063500

目的探讨卵巢癌患者联合采用腹腔热灌注化疗、肿瘤细胞减灭术治疗的临床效果。方法抽取滦南县医院肿瘤外科2019年12月-2022年2月收治的卵巢癌患者80例为研究对象,所有患者均接受肿瘤细胞减灭术治疗,采用随机数字表法将其分为对照组(术... 详细信息

目的探讨卵巢癌患者联合采用腹腔热灌注化疗、肿瘤细胞减灭术治疗的临床效果。方法抽取滦南县医院肿瘤外科2019年12月-2022年2月收治的卵巢癌患者80例为研究对象,所有患者均接受肿瘤细胞减灭术治疗,采用随机数字表法将其分为对照组(术后行静脉化疗)和观察组(术后行腹腔热灌注化疗),每组40例,观察两组肿瘤标志物变化情况,比较两组治疗效果及安全性。结果①对比治疗总有效率,观察组显著高于对照组(P0.05)。结论肿瘤细胞减灭术治疗后,对卵巢癌患者辅助实施腹腔热灌注化疗,可增强机体免疫能力,抑制肿瘤标志物生成,提高临床缓解率,且腹腔热灌注化疗不良反应程度较轻,患者可耐受,该联合疗法值得推广。

关键词：卵巢癌腹腔热灌注化疗肿瘤细胞减灭术

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胸腔镜肺段切除术治疗老年早期非小细胞肺癌近期疗效及对患者肺功能的影响研究

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首都食品与医药 2024年第15期31卷 36-39页

作者：孙卫东河北省滦南县医院河北唐山063500

目的探讨老年早期非小细胞肺癌采取胸腔镜肺段切除术对肺功能的影响,观察近期疗效.方法选择2019年12月-2022年12月收治的120例老年早期非小细胞肺癌患者,将其随机分为对照组和观察组,每组各60例,对照组采取胸腔镜肺叶切除术,观察组采... 详细信息

目的探讨老年早期非小细胞肺癌采取胸腔镜肺段切除术对肺功能的影响,观察近期疗效.方法选择2019年12月-2022年12月收治的120例老年早期非小细胞肺癌患者,将其随机分为对照组和观察组,每组各60例,对照组采取胸腔镜肺叶切除术,观察组采取胸腔镜肺段切除术,观察对比两组患者相关手术指标、肺功能、并发症及术后1年生存情况.结果观察组手术时间(172.31±17.14)min长于对照组(155.69±17.21)min,观察组胸腔引流量(141.32±16.48)mL、术中出血量(162.13±9.47)mL、住院时间(7.12±1.48)d均低于对照组[胸腔引流量(164.85±19.65)mL、术中出血量(170.26±13.16)mL、住院时间(8.62±2.28)d](P0.05).观察组术后3个月FEV1(2.13±0.37)L、PEF(3.69±0.71)L·s、FVC(3.17±0.43)L均高于对照组[FEV1(1.72±0.29)L、PEF(3.05±0.75)L·s、FVC(2.81±0.49)L](P0.05).结论胸腔镜肺段切除术虽然手术时间长,但肺组织切除量少,具有微创优势,可缩短患者住院时间,术后能改善老年早期非小细胞肺癌患者肺功能,且并发症少,近期生存率高,值得应用.

关键词：非小细胞肺癌老年患者胸腔镜手术肺段切除术肺功能近期疗效

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大体积混凝土无缝技术探究

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现代工程科技 2024年第6期3卷 29-32页

作者：孙卫东浙江省东阳第三建筑工程有限公司浙江东阳322100

大体积混凝土无缝技术是房建工程主要使用的技术,需针对混凝土材料特点,以及对使用过程中被外界因素所影响出现的质量问题进行优化处理,从而提出相应的优化措施。分析了房建施工中大体积混凝土结构裂缝的类型和产生原因,提出了房建施工... 详细信息

大体积混凝土无缝技术是房建工程主要使用的技术,需针对混凝土材料特点,以及对使用过程中被外界因素所影响出现的质量问题进行优化处理,从而提出相应的优化措施。分析了房建施工中大体积混凝土结构裂缝的类型和产生原因,提出了房建施工中大体积混凝土无缝技术的应用场景。论述了房建施工中大体积混凝土无缝技术,阐述了大体积混凝土无缝技术要点,即科学配比材料、掌握裂纹情况、加强浇筑工作、完善混凝土振捣、混凝土养护工作。房建施工中合理应用大体积混凝土无缝技术,符合当前建筑行业发展趋势,极具研究价值。

关键词：房建工程大体积混凝土无缝技术

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The big mantle wedge and decratonic gold deposits

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Science China Earth Sciences 2021年第9期64卷 1451-1462页

作者： Rixiang ZHU weidong sun State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China Laboratory for Marine Mineral Resources Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao266237China Center of Deep Sea Research Institute of OceanologyCenter for Ocean Mega-ScienceChinese Academy of SciencesQingdao266071China School of Marine Sciences University of Chinese Academy of SciencesBeing100049China

The Circum-Pacific subduction zone is a famous gold metallogenic domain in the world,with two important gold metallogenic provinces,the North China Craton and Nevada,which are related to the destruction of the North China Craton and the Wyoming Craton,*** ore-forming fluids were possibly derived from the stagnant slab in the mantle transition *** oceanic lithospheric mantle usually contains serpentine layers up to thousands of meters *** plate subduction,serpentine is dehydrated at depths of300 *** overlying big mantle wedge is hydrated during the breakdown of these hydrous facies in the mantle transition *** dehydration of the subducted slab in the big mantle wedge releases sulfur-rich fluid,which extracts gold and other chalcophile elements in the surrounding rocks,forming gold-rich *** the cratonic geotherm is lower than the water-saturated solidus line of lherzolite,the fluid cannot trigger partial ***,it induces metasomatism and forms pargasite and other water-bearing minerals when it migrates upward to depths of less than 100 km in the cratonic lithospheric mantle,resulting in a water-and gold-rich weak *** the destruction of craton,the weak layer is destabilized,releasing gold-bearing fluids that accelerate the *** ore-forming fluids migrate along the shallow weak zone and are accumulated at shallow depths,and subsequently escape along deep faults during major tectonic events,leading to explosive gold *** ore-forming fluids are rich in ferrous iron,which releases hydrogen at low pressure through iron ***,decratonic gold deposits are often reduced deposits.

关键词： Big mantle wedge Serpentine Pargasite Craton destruction Explosive gold mineralization Hydrogen

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Initiation and evolution of the South China Sea: an overview

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Acta Geochimica 2016年第3期35卷 215-225页

作者： weidong sun CAS Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences CAS Key Laboratory of Mineralogy and Metallogeny Guangzhou Institute of Geochemistry Chinese Academy of Sciences

Different models have been proposed for the formation and tectonic evolution of the South China Sea(SCS), including extrusion of the Indochina Peninsula,backarc extension, two-stage opening, proto-SCS dragging,extension induced by a mantle plume, and integrated models that combine diverse factors. Among these, the extrusion model has gained the most attention. Based on simpli?ed physical experiments, this model proposes that collision between the Indian and Eurasian Plates resulted in extrusion of the Indochina Peninsula, which in turn led to opening of the SCS. The extrusion of the Indochina Peninsula, however, should have led to preferential opening in the west side of the SCS, which is contrary to observations. Extensional models propose that the SCS was a backarc basin, rifted off the South China Block. Most of the backarc extension models, however, are not compatible with observations in terms of either age or subduction direction. The two-stage extension model is based on extensional basins surrounding the SCS. Recent dating results indeed show two-stage opening in the SCS, but the Southwest Subbasin of the SCS is much younger, which contradicts the two-stage extension model. Here we propose a re?ned backarc extension model. There was a wide Neotethys Ocean between the Australian and Eurasian Plates before the Indian-Eurasian collision. The ocean ?oor started to subduct northward at *125 Ma, causing backarc extension along the southern margin of the Eurasian Plate and the formation of the proto-SCS. The Neotethys subduction regime changed due to ridge subduction in the Late Cretaceous, resulting in fold-belts, uplifting, erosion, and widespread unconformities. It may also have led to the subduction of the proto-SCS. Flat subduction of the ridge may have reached further north and resulted in another backarc extension that formed the SCS. The rollback of the?at subducting slab might have occurred *90 Ma ago; the second backarc extension may have initiated betwee

关键词： South China Sea Neotethys Plate subduction Ridge subduction Indochina Peninsula extrusion Backarc extension Multiple plate interactions Proto-South China Sea

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The Magma Engine and subduction initiation

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Acta Geochimica 2019年第5期38卷 611-612页

作者： weidong sun Center of Deep Sea Research Institute of OceanographyCenter for Ocean Mega-Science Chinese Academy of Sciences Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology

The plate tectonics theory is a milestone in solid Earth ***,50 years after the theory has been proposed,the driving force behind plate drifts is still controversial(sun 2016).Slab pull has been accepted as the dominant driving force of plate tectonics for a long time(Forsyth and Uyeda 1975).A major challenge of this model is how plate subduction was initiated in the first place(Arculus et al.2015,2019;Li et al.2019;Niu 2016;Niu et al.2003;O'Connor et al.2015;sun 2016,2017;Zhou et al.2018).

关键词： Magma Engine subduction initiation

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