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Potassium isotopic signatures of modern offshore detrital sediments from different climatic regimes and the implications

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Science China Earth Sciences 2024年第2期67卷 405-419页

作者： Jun MU Tianyu chen Qian YU Shichao AN jianfang chen Xuefa SHI Weiqiang LI State Key Laboratory for Mineral Deposits Research School of Earth Sciences and EngineeringNanjing UniversityNanjing210023China Ministry of Education Key Laboratory for Coast and Island Development School of Geography and Ocean ScienceNanjing UniversityNanjing210023China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou310012China Key Laboratory of Marine Geology and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao266061China

Potassium isotopes are a novel tracer for continental *** K isotope studies on chemical weathering generally targeted weathering profiles under a particular climate region,yet the effects of chemical weathering on K isotopes under different climatic backgrounds remain ***,little is known about the K isotope signatures of modern unconsolidated detrital ***,we report K isotopic data of surficial seafloor sediments from continental shelves along the east coast of China(ECC),as well as those around the tropical Hainan island in the northern South China *** ECC sediments have a relatively narrow distribution ofδ^(41)K(with reference to NIST3141a)values,which range from(-0.40±0.01)‰to(-0.57±0.04)‰,with an average of(-0.51±0.09)‰.By contrast,δ^(41)K values of Hainan offshore sediments display a larger variation,ranging from(-0.28±0.07)‰to(-0.67±0.02)‰.Theδ^(41)K values of Hainan offshore sediments exhibit negative correlations with the chemical index of alteration(CIA),Al/K,Ti/K,and total iron(FeT),which underlines the control of chemical weathering on K isotopic signatures of detritus inputs into *** also measured Mg isotope compositions for the same samples;interestingly,the variability inδ^(26)Mg of the samples is small(~0.24‰)for all ECC and Hainan offshore sediments,andδ^(26)Mg values do not show clear correlations with indexes of chemical *** study demonstrates the link between K isotopic variability of detrital sediments and climatic conditions including rainfall intensity,which indicates that K isotopes of the detrital component of marine sediments could be applied to study Earth’s climate in deep ***δ^(41)K values of the offshore detrital sediments are significantly less variable than those of pelagic marine sediments,highlighting the importance of distinguishing the effects of diagenesis and neoformation of clay minerals from continental weathering in attempts to study deep-time climate-weathering

关键词： Potassium isotopes Magnesium isotopes Chemical weathering Detrital sediments Climatic regimes Mean annual precipitation

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Tracing nitrate sources in one of the world's largest eutrophicated bays(Hangzhou Bay):insights from nitrogen and oxygen isotopes

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Acta Oceanologica Sinica 2024年第6期43卷 86-95页

作者： Zhi Yang jianfang chen Haiyan Jin Hongliang Li Zhongqiang Ji Yangjie Li Bin Wang Zhenyi Cao Qianna chen Key Laboratory of Marine Ecosystem Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China

Eutrophication caused by inputs of excess nitrogen(N) has become a serious environmental problem in Hangzhou Bay(China),but the sources of this nitrogen are not well *** this study,the August 2019 distributions of salinity,nutrients [nitrate(NO_(3)^(-)),nitrite,ammonium,and phosphate],and the stable isotopic composition of NO_(3)^(-)(δ^(15)N and δ^(18)O) were used to investigate sources of dissolved inorganic nitrogen(DIN) to Hangzhou B *** distributions of nitrate,salinity,and nitrate δ^(18)O indicate that the Qiantang River,the Changjiang River,and nearshore coastal waters may all contribute nitrate to the *** on the isotopic compositions of nitrate in these potential source waters and conservative mixing of nitrate in our study area,we suggest that the NO_(3)^(- )in Hangzhou B ay was likely derived mainly from soils,synthetic N fertilizer,and manure and ***-member modeling indicates that in the upper half of the bay,the Qiantang River was a very important DIN source,possibly contributing more than 50% of DIN in the bay head *** the lower half of the bay,DIN was sourced mainly from strongly intruding coastal *** coming directly from the Changjiang River made a relatively small contribution to Hangzhou Bay DIN in August 2019.

关键词： nitrogen isotopes oxygen isotopes nitrogen cycle nitrate sources Hangzhou Bay

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Biogeochemistry of sedimentary organic matter in the Yongjiang River estuary in the southern part of Hangzhou Bay,China,since the Late Pleistocene

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Journal of Oceanology and Limnology 2024年第3期42卷 772-786页

作者： Dongqin HUANG Xiaolong LI Zilong LI Pei Sun LOH Jianxiong HU jianfang chen Yuan-Pin CHANG Chin-Wen YANG Qin GAO Institute of Marine Geology and Resources Ocean CollegeZhejiang UniversityZhoushan 316021China Ministry of Water Resources of the People’s Republic of China Beijing 100054China Key Laboratory of Marine Ecosystem Dynamics Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Department of Oceanography Sun Yat-sen UniversityKaohsiung 80424China

A sediment core(YJK19-02)collected from the southern outlet of Hangzhou Bay near the Yongjiang River estuary in East China was analyzed for grain size,lignin,bulk elemental composition,stable carbon isotope,and rare earth elements(REEs)to determine the sources and diagenesis of sedimentary organic matter(OM)of the estuary and adjacent areas since the Late Pleistocene.δ^(13)C values(-24.80‰–-23.60‰),total organic carbon/total nitrogen(TOC/TN)molar ratios(8.00–12.14),and light rare earth element/heavy rare earth element ratios(LREE/HREE=8.34–8.91)revealed the predominance of terrestrial sources of OM,mainly from the Changjiang(Yangtze)*** lignin parameters of syringyl/vanillyl(S/V=0.20–0.73)and cinnamyl/vanillyl(C/V=0.03–0.19)ratios indicate the predominance of nonwoody angiosperms,and the vanillic acid/vanillin ratios[(Ad/Al)_(V)=0.32–1.57]indicate medium to high degrees of lignin *** increasing trend ofΛ(total lignin in mg/100-mg OC)values from ca.14500 a BP to ca.11000 a BP reflected the increase in temperature during the Late ***,a time lag effect of temperature on vegetation abundance was also *** relatively higher and stableΛvalues correspond to the higher temperature during the mid-Holocene from ca.8500 a BP to ca.4500 a BP.Λvalues decreased from ca.4000 a BP to the present,corresponding to historical temperature fluctuations during this *** results show that the vegetation abundance in the Yongjiang River Basin since the Late Pleistocene was related to the temperature fluctuation duo to climate change.

关键词： Yongjiang River estuary sedimentary organic matter lignin environmental change Late Pleistocene

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SUPPRESSION OF SIDELOBES IN SINGLE-PHOTON 4PI CONFOCAL MICROSCOPY BY FORSTER RESONANT ENERGY TRANSFER

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Journal of Innovative Optical Health Sciences 2012年第3期5卷 28-33页

作者： jianfang chen YA chenG Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences No.390Qinghe RoadJiading P.O.Box 800-211Shanghai 201800P.R.China State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences No.390Qinghe RoadJiading P.O.Box 800-211Shanghai 201800P.R.China

Recently,we theoretically demonstrate that utilization of silica nanobeads co-doped with Cy3 and Cy5 molecules instead of single dye molecules asfluorescent labels can enable optical resolutions far beyond the ***,we show that by combining the 4Pi microscopy and the novelfluorescent label,it is possible to completely suppress the sidelobes in 4Pi focal spot and significantly enhance the optical resolution in the axial direction.

关键词： Fluorescent dye 4Pi microscopy far-field imaging super-resolution confocal

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The size-fractionated chlorophyll a and primary productivity in the Bering Sea during the summer of 2003

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Acta Oceanologica Sinica 2005年第6期24卷 127-134页

作者： LIU Zilin chen jianfang chen Zhongyuan ZHANG Tao ZHANG Haisheng Key Laboratory of Marine Ecosystem and Biogeochemistry State Oceanic AdministrationHangzhou 310012China Key Laboratory of Ocean Dynamic Processes and Satellite Oceanography State Oceanic AdministrationHangzhou 310012China

Investigations of chlorophyll a and primary productivity were carried out inthe Bering Sea along the BR line and the BS line during the Second Chinese National Arctic ResearchExpedition in the summer of *** results showed that the surface chlorophyll a concentrationswere 0.199~1.170μg/dm^(3),and the average value was 0.723μg/dm^(3) on the BR *** the BSline,the surface chlorophyll a concentrations were 0.519~4.644μg/dm^(3)(average 1.605μg/dm^(3))and 0.568~14.968μg/dm^(3)(average 5.311μg/dm^(3))during the early and late summer,*** average value in the late summer was much higher than that in the early *** high values(more than 4.0μg/dm^(3))occurred at stations of the BS line in the southern Bering *** a concentrations in the subsurface layer were higher than those in the surface *** results of the size-fractionated chlorophyll a showed that the contribution of the picoplanktonto total chlorophyll a was the predominance at the early summer and the contribution of thenetplankton was the predominance at the late *** carbon potential primary productivitiesvaried between 0.471 and 1.147 mg/(m^(3)·h)on the BR line,with average rates of 0.728 mg/(m^(3)·h).The primary productivities on the BS line were much higher than those of the BR line,ranging from1.227 mg/(m^(3)·h)at the early summer to 19.046 mg/(m^(3)·h)at the late *** results of thesize-fractionated primary productivity showed that the contribution of the nanoplankton to totalproductivity was the predominance at the early summer and the contribution of the netplankton waspredominance at the late *** assimilation number of photosynthesis was 0.45~2.80 mg/(mg·h)in the surveyed stations.

关键词： chlorophyll a primary productivity the size-fractionated bering sea

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种植密度对大棚辣椒生长、品质及产量的影响

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中国瓜菜 2024年第7期37卷 119-124页

作者：顾桂兰张雪平陈建芳张瑞花靳艳革濮阳市农林科学院河南濮阳457000

为了探明种植密度对早春大棚辣椒生长、品质和产量的影响,以辣椒新品种濮椒6号为试验材料,采用单因素随机区组试验,设置5个种植密度处理,研究了不同种植密度对早春大棚辣椒植株、果实、叶绿素含量、光合特性、品质和产量的影响。结果表... 详细信息

为了探明种植密度对早春大棚辣椒生长、品质和产量的影响,以辣椒新品种濮椒6号为试验材料,采用单因素随机区组试验,设置5个种植密度处理,研究了不同种植密度对早春大棚辣椒植株、果实、叶绿素含量、光合特性、品质和产量的影响。结果表明,随着种植密度增加,辣椒株高逐渐增加,而株幅、茎粗、果宽、果长则逐渐减少。随着种植密度的增加,辣椒盛果期叶片的叶绿素含量、净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)呈逐渐降低趋势,而辣椒叶片胞间CO_(2)浓度(Ci)则逐渐升高;辣椒果实可溶性蛋白、可溶性糖、维生素C含量逐渐降低,但对辣椒素含量没有显著影响。随着种植密度的增加,辣椒单果质量和商品果数呈逐渐降低趋势,而产量呈先升高后降低的趋势,当种植密度处理A2为2223株·667 m^(-2)时,其产量显著高于其他处理。综上所述,2223株·667 m^(-2)为早春大棚辣椒濮椒6号的适宜种植密度。

关键词：辣椒大棚种植密度光合特性生长产量品质

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Mechanisms leading to the frequent occurrences of hypoxia and a preliminary analysis of the associated acidification off the Changiiang estuary in summer

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Science China Earth Sciences 2017年第2期60卷 360-381页

作者： WEI QinSheng WANG BaoDong YU ZhiGang chen jianfang XUE Liang Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationOcean University of ChinaQingdao 266100China First Institute of Oceanography State Oceanic AdministrationQingdao 266061China Laboratory of Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China Second Institute of Oceanography State Oceanic AdministrationHangzhou 310012China

Based on literature data and shipboard observations,this study investigated the main environmental characteristics of the seafloor topography,current field,front,and upwelling that are closely related to hypoxia occurrence off the Changjiang *** physical processes of the plume front and upwelling off the Changjiang estuary in summer were *** vertical distribution pattern of the plume front was closely related to the *** reviewing and analyzing the historical summer hypoxia events off the Changjiang estuary,we statistically demonstrated the spatial structure of the horizontal distribution of the hypoxic zone and investigated the location of occurrence zone of the *** found that the dissolved oxygen(DO)concentration on the inner continental shelf off the estuary showed a"V"shape in relation to station ***,we noted that the hypoxic water on the inner continental shelf mostly occurred on the slopes with steep seafloor *** on the current understanding of the hypoxic mechanisms off the Changjiang estuary,we analyzed the biogeochemical mechanisms that could cause the steep terrain off the Changjiang estuary to become the main areas prone to summer hypoxia and explained the internal relations between the location of the hypoxic zone on the slopes and the plume front and *** plume front and upwelling off the Changjiang estuary and their coupling were important driving forces of summer *** continuous supply of nutrients affected by the interaction of the plume front extension of the Changjiang Diluted Water(CDW)and upwelling and the favorable light conditions were important mechanisms causing the phytoplankton blooms and benthic hypoxia off the Changjiang estuary in *** analyzing oxygen utilization,organic carbon mineralization,and nutrient regeneration in the hypoxic zone,we observed that the significant oxygen utilization process off the Changjiang estuary in summer also mainly occurred near the

关键词： Changjiang estuary Hypoxic zone Upwelling Front Nutrient regeneration Biogeochemistry Acidification

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东西伯利亚陆架炭屑分布特征及其控制因素

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极地研究 2024年第2期36卷 113-127页

作者：俞心婷任健边叶萍李中乔林龙金海燕陈建芳上海交通大学海洋学院上海200030 自然资源部海洋生态系统动力学重点实验室自然资源部第二海洋研究所浙江杭州310012 自然资源部海底科学重点实验室自然资源部第二海洋研究所浙江杭州310012 中国极地研究中心(中国极地研究所) 上海200136

炭屑是指示火灾事件的重要指标。全球变暖背景下,环北极地区野火频发,了解炭屑的产生、迁移和埋藏对理解北极气候变化的环境效应及陆源碳源汇过程具有重要意义,而前人对北极海域的炭屑研究十分匮乏。东西伯利亚陆架是全球最大的陆架区,... 详细信息

炭屑是指示火灾事件的重要指标。全球变暖背景下,环北极地区野火频发,了解炭屑的产生、迁移和埋藏对理解北极气候变化的环境效应及陆源碳源汇过程具有重要意义,而前人对北极海域的炭屑研究十分匮乏。东西伯利亚陆架是全球最大的陆架区,接收和封存着巨量的陆源碳,也是海冰融化、沿岸侵蚀、周边野火频发最显著的地区,因此成为研究北极炭屑记录的重要区域。本文基于2016年首次中俄北极联合科学考察取得的表层沉积物样品,研究了东西伯利亚陆架区不同粒度炭屑的空间分布特征、输运方式及其控制因素。结果表明,东西伯利亚陆架区表层沉积物中炭屑总浓度为4.4×10^(4)~4.1×10^(6)粒·g^(–1),平均浓度为9.3×10^(5)粒·g^(–1)。沉积物中炭屑呈现近岸粗、远岸细的总体分布特征。由于受到水动力、大气等长距离搬运,研究区炭屑颗粒以超细粒为主(平均占83%)。河口水动力作用、沿岸侵蚀、大气传输、海冰搬运、水平向和垂向上的海流搬运等多重控制因素,可能共同影响炭屑的跨陆架输运过程。

关键词：北极快速变化东西伯利亚陆架炭屑输运过程陆源输入

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Wheel Setting Error Modeling and Compensation for Arc Envelope Grinding of Large-Aperture Aspherical Optics

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 87-99页

作者： Changsheng Li Lin Sun Zhaoxiang chen jianfang chen Qijing Lin Jianjun Ding Zhuangde Jiang State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an 710049China School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China Shaanxi Qinchuan Precision CNC Machine Tool Engineering Research Co Xi’an 710018China

Precision grinding is a key process for realizing the use of large-aperture aspherical optical elements in laser nuclear fusion devices,large-aperture astronomical telescopes,and high-resolution space *** this study,the arc envelope grinding process of large-aperture aspherical optics is investigated using a CM1500 precision grinding machine with a maximum machinable diameter ofΦ1500 *** form error of the aspherical workpiece induced by wheel setting errors is analytically modeled for both parallel and cross *** show that the form error is more sensitive to the wheel setting error along the feed direction than that along the lateral *** is a bilinear function of the feed-direction wheel setting error and the distance to the optical *** on the error function above,a method to determine the wheel setting error is ***,grinding tests are performed with the wheels aligned *** a newly proposed partial error compensation method with an appropriate compensation factor,a form error of 3.4μm peak-to-valley(PV)for aΦ400 mm elliptical K9 glass surface is achieved.

关键词： Aspherical optics Wheel setting Arc envelope grinding Form error Large aperture

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Sources and distribution of sedimentary organic matter along the northern Bering and Chukchi Seas

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Journal of Environmental Sciences 2017年第2期29卷 66-75页

作者： Fanglu Xu Haiyan Jin Zhongqiang Ji jianfang chen Pei Sun Loh Institute of Marine Chemistry and Environment Department of Marine Sciences Ocean College Zhejiang University Laboratory of Marine Ecosystem and Biogeochemistry Second Institute of OceanographyThe State Oceanic Administration

In this study, lignin-derived phenols were used to determine the sources and distribution of sedimentary organic matter along the northern Bering Sea and Chukchi Sea of the Arctic Ocean. The lignin parameter syringyl/vanillyl（S/V） and cinnamyl/vanillyl（C/V） ratios are used to indicate vegetation sources; and the ratios of vanillic acid/vanillin,（Ad/Al）v and syringic acid/syringaldehyde,（Ad/Al）s are used as indicators of lignin diagenesis. Results showed the predominance of woody gymnosperm signal at the easternmost location in the northern Bering Sea, a mixture of refractory non-woody angiosperm and fresher gymnosperm tissues in the Chukchi Sea, and signal of fresher woody gymnosperm tissues in the northernmost locations in the Chukchi Sea. The lignin materials showed gradual increase in decomposition stage during transport along the northern Bering Sea. Hydrodynamic sorting process, which is the retention of coarser materials nearshore and transportation of finer particles farther offshore, most probably occurred along the east coast of the northern Bering Sea. In Chukchi Sea, the non-woody angiosperm tissues could have originated from the Canadian Arctic and gymnosperm tissues could be from the Russian Arctic side. The fresher materials in the northernmost Chukchi Sea could have been transported here via the ice-rafting *** of fresh lignin materials and the occurrence of lignin decomposition mean that this region could be sensitive to the impact of climate change.

关键词： Lignin-derived phenols Northern Bering Sea Chukchi Sea

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