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Upwelling and anthropogenic forcing on phytoplankton productivity and community structure changes in the Zhejiang coastal area over the last 100 years

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Acta Oceanologica Sinica 2014年第10期33卷 1-9页

作者： DUAN Shanshan XING Lei ZHANG Hailong feng xuwen YANG Haili ZHAO Meixun Key Laboratory of Marine Chemistry Theory and Technology (Ocean University of China) Ministry of Education Qingdao Collaborative Innovation Center of Marine Science and Technology Second Institute of Oceanography State Oceanic Administration

Phytoplankton productivity and community structure in marginal seas have been altered significantly during the past three decades, but it is still a challenge to distinguish the forcing mechanisms between climate change and anthropogenic activities. High time-resolution biomarker records of two 210Pb-dated sediment cores（#34： 28.5°N, 122.272°E; CJ12-1269： 28.861 9°N, 122.515 3°E） from the Min-Zhe coastal mud area were compared to reveal changes of phytoplankton productivity and community structure over the past 100 years. Phytoplankton productivity started to increase gradually from the 1970 s and increased rapidly after the late 1990 s at Site #34; and it started to increase gradually from the middle 1960 s and increased rapidly after the late 1980 s at Site CJ12-1269. Productivity of Core CJ12-1269 was higher than that of Core #34. Phytoplankton community structure variations displayed opposite patterns in the two cores. The decreasing D/B（dinosterol/brassicasterol） ratio of Core #34 since the 1960 s revealed increased diatom contribution to total productivity. In contrast, the increasing D/B ratio of Core CJ12-1269 since the 1950 s indicated increased dinoflagellate contribution to total productivity. Both the productivity increase and the increased dinoflagellate contribution in Core CJ12-1269 since the 1950–1960s were mainly caused by anthropogenic activities, as the location was closer to the Changjiang River Estuary with higher nutrient concentration and decreasing Si/N ratios. However, increased diatom contribution in Core #34 is proposed to be caused by increased coastal upwelling, with higher nutrient concentration and higher Si/N ratios.

关键词： biomarkers phytoplankton community structure Min-Zhe coastal mud area Changjiang Diluted Water upwelling

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Dynamic performance of an integrated heat pump system coupled free cooling and waste heat recovery in data centers

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ENERGY 2025年 323卷

作者： Zhou, feng Tian, xuwen Song, Yu Ma, Guoyuan Beijing Univ Technol Dept Refrigerat & Cryogen Engn Beijing 100124 Peoples R China Key Lab Heat Transfer & Energy Convers Beijing Peoples R China

Recovering and reusing this waste heat for district heating is an effective strategy to enhance energy efficiency in data centers. To align data center waste heat recovery with heat consumer demand and improve energy utilization, a transient mathematical model of a data center-integrated heat pump district heating system was developed and validated. A case study involving a small data center with 300 standard racks in Beijing was conducted to analyze the system's operational and dynamic behavior. The results show that hot water and heating account for 35.70 % and 64.30 % of the total heat consumption, respectively. During the heating season, the heating heat pump unit exhibits a high heating coefficient of performance (COP), with a maximum heating COP of 5.27. Under year-round operation, the COP of the hot water heat pump unit exhibited periodic 24-h variations. Peak water consumption occurred from 6:00 to 9:00 and 21:00 to 24:00, with corresponding heating COP values of 3.87 and 4.24, respectively. The proposed system in addressing the cooling demand of the data center and the heating and hot water demands of the heat consumers, providing a feasible solution for improving the energy utilization efficiency of data centers.

关键词： Data center Waste heat recovery Dynamic performance analysis Integrated heat pump district heating system

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Sedimentary records of eutrophication in the Changjiang Estuary upwelling area over last 100 a

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Acta Oceanologica Sinica 2008年第6期27卷 49-61页

作者： feng xuwen JING Xianglong YU Xiaoguo LI Hongliang CHEN Jianfang QIAN Jiangchu Geology Science Department Zhejiang University Hangzhou 310027 China Second Institute of Oceanography State Oceanic Administration Hangzhou 310012 China Laboratory of Submarine Geosciences of State Oceanic Administration Second Institute Oceanography State Oceanic Adminis-tration Hangzhou 310012 China Laboratory of Marine Ecosystem and Biogeochemistry of State Oceanic Administration Second Institute Oceanography StateOceanic Administration Hangzhou 310012 China

The upwelling area in the Changjiang Estuary was selected to collect the core, where the red tide occurred frequently and hypoxic existed. The total organic carbon （TOC）, total nitrogen （TN）, biogenic silica （BSi） and stable organic carbon isotopic ratios（δ13 Corg） were determined on the 210pb-dated sediment core. The concentrations of TOC, TN, BSi as well as their sedimentation fluxes have in- creased to some extent since the 1970s. TOC and TN fluxes increased about 45%, 36% respectively. The average δ13 Coorg value in the core was -23.67 ×10^-3 which remained nearly constant before the 20 century. The δ13 Corg values increased after the 1900s, two marked increases were observed from the 1950s and the 1970s. A simple δ13 Cors model was used to estimate the contribution of terrigenous and marine organic matter inputs for the sediment, which indicated the increase in accumulation since the 1970s has been almost exclusively marine. The increasing of marine organic matter accumulation （TOC, TN and BSi） was corresponding with the increasing of fertilizer consumption and the NO3-N budgets from the Changjiang River. The riverine runoff of fertilizers and nutrients stimulated the algae blooming. Enhanced primary production resulted in an enrichment of organic matter in the sediment. These data support the hypothesis that anthropogenic nutrient loading has been a significant factor on the eutrophication in the Changjiang Estuary.

关键词： Changjiang Estuary total organic carbon total nitrogen biogenic silica stable carbon isotopes eutrophication

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Sedimentary organic and inorganic records of eutrophication and hypoxia in and off the Changjiang Estuary over the last century

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MARINE POLLUTION BULLETIN 2015年第1-2期99卷 76-84页

作者： Zhao, Jun feng, xuwen Shi, Xiaolai Bai, Youcheng Yu, Xiaoguo Shi, Xuefa Zhang, Weiyan Zhang, Rongping State Ocean Adm Inst Oceanog 2 Hangzhou 310012 Zhejiang Peoples R China SOA Key Lab Marine Ecosyst & Biogeochem Hangzhou 310012 Zhejiang Peoples R China SOA Key Lab Submarine Geosci Hangzhou 310012 Zhejiang Peoples R China SOA Inst Oceanog 1 Key Lab Marine Sedimentol & Environm Geol Qingdao 266061 Peoples R China Ocean Univ China Minist Educ Key Lab Marine Chem Theory & Technol Qingdao 266100 Peoples R China

Organic and inorganic sedimentary parameters in and off the Changjiang Estuary have been analyzed to reconstruct historical trends in eutrophication and hypoxia over the last century. The lipid biomarker concentrations in the Changjiang Estuary mud area,(CEMA) indicated eutrophication accelerated after the 1970s. Meanwhile, Mo/Al indicated hypoxia has increased since 1960s. Eutrophication and hypoxia in the CEMA are primarily a result of the dramatically increased load of terrestrial nutrients from the Changjiang to the East China Sea. The lipid biomarker concentrations in the southwest Cheju Island mud area (SCIMA) showed primary production is controlled mainly by changes in regional climate and marine current. No significant hypoxia occurred in the SCIMA over the past century as indicated by Mo/Al. Therefore, geochemical indicators of eutrophication and hypoxia revealed different patterns between the CEMA and SCIMA, suggesting the role of river-derived nutrients in sustaining eutrophication and hypoxia in the CEMA since the 1960s. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Changjiang Estuary Eutrophication Hypoxia Biomarker Redox sensitive element Sediments

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The synthesis of an iron tailings-based geopolymer with synergistic electromagnetic wave consumption property

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ENVIRONMENTAL RESEARCH 2025年 268卷 120744页

作者： Wang, Tianyu Ning, xuwen Yang, Lang Rao, feng Jiang, Kaixi Fuzhou Univ Sch Mat Sci & Engn Fuzhou 350108 Fujian Peoples R China Fuzhou Univ Zijin Sch Geol & Min Fuzhou 350108 Fujian Peoples R China Fuzhou Univ Fujian Key Lab Green Extract & High Value Utilizat Fuzhou 350108 Fujian Peoples R China

In this study, combination of wave absorption materials with different loss mechanisms are added into iron ore tailings-blast furnace slag (IOT-BFS) based geopolymers. The employed materials are hollow glass microsphere (HGM), carbon nanotubes (CNT) and carbonyl iron powder (CIP). Microstructures of the geopolymers are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and concrete porous structure analyzer. Conductivity and electromagnetic absorption property of the geopolymers are measured by a conductivity tester and a vector network analyzer (VNA). As increasing the content of wave absorption materials, compressive strength of the geopolymer decreased from 60.5 to 33.8 MPa. Compared with geopolymers containing HGM and CNT, wave absorption band below -5 dB of the geopolymers with HGM and CIP was wider, particularly at frequencies below 7 GHz, due to the synergism of space and magnetic loss. Its absorption bandwidth with the reflection loss less than -5 dB reaches 15.6 GHz. This study gives a clue for preparation of geopolymers with satisfactory electromagnetic wave absorption properties in the utilization as construction materials.

关键词： Geopolymers Electromagnetic wave absorption Iron ore tailings Microstructure

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Ladderane records over the last century in the East China sea: Proxies for anammox and eutrophication changes

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WATER RESEARCH 2019年第Jun.1期156卷 297-304页

作者： Zhao, Zongshan Cao, Yali Fan, Ying Yang, Haili feng, xuwen Li, Li Zhang, Hailong Xing, Lei Zhao, Meixun Ocean Univ China Inst Adv Ocean Study Minist Educ Key Lab Marine Chem Theory & Technol Qingdao 266100 Shandong Peoples R China Qingdao Natl Lab Marine Sci & Technol Lab Marine Ecol & Environm Sci Qingdao 266237 Shandong Peoples R China Chinese Acad Sci Qingdao Inst Bioenergy & Bioproc Technol CAS Key Lab Biobased Mat Qingdao 266101 Shandong Peoples R China Jiangxi Inst Anal & Test Nanchang 330029 Jiangxi Peoples R China State Ocean Adm Inst Oceanog 2 Hangzhou 310012 Zhejiang Peoples R China

Anaerobic ammonium oxidation (anammox), an important process for converting fixed nitrogen to N-2, plays an important role in the present-day marine nitrogen cycle. However, little is known about anammox activities in the past, especially in regions that were strongly affected by human activities, evidenced by eutrophication and hypoxia, which promote anammox bacteria growth. In this study, ladderanes have been measured in a sediment core and suspended particulate matter (SPM) in the East China Sea (ECS), to reconstruct the anammox record and to evaluate its responses to eutrophication and hypoxia. The detection and distribution of different ladderane lipids in SPM provide additional evidence that ladderanes were mostly produced in the water column and could reflect anammox activities. Summed ladderane content from the core varied between 11 and 300 ng/g dry weight (dw) sediment, with C20-[5]-ladderane fatty acid methyl esters (FAME) as the predominant compound (5-150 ng/g dw), followed by C20-[3]-ladderane FAME (1-110 ng/g dw), C18-[3]-ladderane FAME (1-32 ng/g dw) and 08 -[5]-ladderane FAME (3-11 ng/g dw). The detection of ladderanes over the last century indicate the existence of anammox in the past. The rapidly increasing trend of ladderanes since the 1960s correlates with an increase in phytoplankton biomarkers (2 Sigma(B + D + A), brassicasterol (B), dinosterol (D) and C-37 alkenones (A)), indicating that eutrophication exacerbated anammox growth. The co-variation between our ladderane record and published records of low-oxygen tolerant foraminiferal microfossils and hypoxia events over the past 60 years suggested that sediment ladderanes are a useful indicator for past changes of oxygen depletion or hypoxia in the ECS. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Anammox Ladderanes Nitrogen cycle Phytoplankton Hypoxia

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A novel electromagnetic wave absorption geopolymer originated from iron tailings and blast furnace slag

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MATERIALS AND STRUCTURES 2025年第1期58卷 1-14页

作者： Ning, xuwen Yang, Lang Rao, feng Wang, Tianyu Wu, Shengping Huang, Hanhui Fuzhou Univ Zijin Sch Geol & Min Fuzhou 350108 Fujian Peoples R China Zhiyong Construct Grp Co Ltd Fuzhou 350800 Fujian Peoples R China Fuzhou Univ Fujian Key Lab Green Extract & High Value Utilizat Fuzhou 350108 Fujian Peoples R China State Key Lab Mineral Proc Beijing 102628 Peoples R China Fujian JiangXia Univ Sch Engn Fuzhou 350108 Fujian Peoples R China Zhongke Chengfa Fujian Construct Grp Co Ltd Nanping 354105 Fujian Peoples R China Coll Civil Engn Fujian ChuanZheng Commun Coll Fuzhou 350007 Fujian Peoples R China

In this work, a novel electromagnetic wave absorption geopolymer was created with efficient utilization of two solid wastes iron tailings and blast furnace slag, meanwhile the mechanism and impacts of iron tailings content, water-solid ratio and specimen thickness on their electromagnetic wave absorption and mechanical property were systematically investigated. It was found the pores, micro-cracks and unreacted particles in the specimens are benefitial for electromagnetic wave absorption but against to compressive strength, even though the compressive strength reaches 69.7 MPa with the iron tailings content 50% and water-solid ratio 0.4. The addition of iron tailings significantly enhances the electromagnetic wave absorption properties of the geopolymers, and increasing iron tailings content improves the number of pores, micro-cracks and the permeability of geopolymers. The electromagnetic wave absorption properties of the geopolymer initially increase and then decrease with the increase of specimen thickness and water-solid ratio. With an iron tailings content 70%, water-solid ratio 0.4 and thickness 30 mm, the effective absorption bandwidth (< -5 dB) was optimized to 10.44 GHz with a minimum reflection loss of -13.34 dB. A new mechanism for electromagnetic absorption in iron tailings has been proposed, in which the electromagnetic wave absorption of geopolymers is mainly dominated by magnetic loss and spatial propagation loss. This study provides higher competitiveness and comprehensive utilisation of iron tailings in the field of electromagnetic wave absorbing building materials, and has great potential for applications in military and other fields affected by high electromagnetic wave frequencies.

关键词： Iron tailings Geopolymers Microwave absorption Reflectivity

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Ecosystem responses to anthropogenic and natural forcing over the last 100 years in the coastal areas of the East China Sea

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HOLOCENE 2016年第5期26卷 669-677页

作者： Xing, Lei Zhao, Meixun Zhang, Ting Yu, Meng Duan, Shanshan Zhang, Rongping Huh, Chih-An Liao, Wen-Hsuan feng, xuwen Ocean Univ China Key Lab Marine Chem Theory & Technol Minist Educ Qingdao 266100 Peoples R China Qingdao Collaborat Innovat Ctr Marine Sci & Techn Qingdao Peoples R China Acad Sinica Inst Earth Sci Taipei Taiwan Acad Sinica Res Ctr Environm Changes Taipei Taiwan Acad Sinica Earth Syst Sci Taiwan Int Grad Program Taipei Taiwan State Ocean Adm Inst Oceanog 2 Qingdao Peoples R China

Ecosystem changes of the coastal areas of the East China Sea (ECS) during the past 30 years have been characterized by increased productivity and increased occurrences of dinoflagellate red tides;both were commonly attributed to be caused by anthropogenic input of nutrients. However, climate-driven regime shifts were found in the Pacific, but they have not been observed in the ECS owing to the lack of continuous high resolution data. Hence, it is still a challenge to distinguish the influences of anthropogenic activities and climate changes on ECS shelf ecosystem. We compare phytoplankton biomarker (brassicasterol, dinosterol, and alkenones) data of five box cores from the coastal area of the ECS, which afford phytoplankton productivity and community structure records at decadal-scale resolution for the last 100 years. Phytoplankton productivity in all cores increased during the past 50 years, but community structure changes showed different trends. Relative diatom contribution revealed a decreasing trend during the past ca. 50 years in cores DH5-1 and CJ43 collected near the Changjiang Estuary, which were likely caused by increased N/Si and N/P ratios, providing conditions more favorable for dinoflagellates growth. In contrast, the relative diatom contribution increased in cores 32, 34, and DH6-3 further away and south of the Changjiang Estuary, suggesting limited influence of the Changjiang water. Instead, diatom increasing trend is likely caused by increased supply of phosphorus and silicate, as a result of larger Kuroshio intrusion flux and the corresponding strengthened coastal upwelling. Therefore, both anthropogenic activities and climate-driven coastal upwelling have contributed to increased productivities, but these two forcing mechanisms have resulted in contrasting community structure changes at different sites in the coastal area of the ECS.

关键词： biomarkers Changjiang River coastal upwelling Kuroshio phytoplankton community structure the East China Sea

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Beyond transcription, aryl hydrocarbon receptor plays a protective role in periodontitis by interacting with CaMKII

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JOURNAL OF PERIODONTOLOGY 2025年第1期96卷 67-81页

作者： Zeng, xuwen feng, Meiting Lu, Jiawei Wang, Ruiling Deng, Li Yang, Yanan Luo, Lijun Tongji Univ Stomatol Hosp Shanghai Engn Res Ctr Tooth Restorat & Regenerat Dept Periodontol Shanghai Peoples R China Tongji Univ Shanghai Engn Res Ctr Tooth Restorat & Regenerat Dent Sch Shanghai Peoples R China Univ Porto Inst Res & Innovat Hlth i3S Inst Invest & Inovacao Saude Porto Portugal Univ Porto Inst Mol & Cell Biol IBMC Inst Biol Mol & Celular Porto Portugal

Background: The aryl hydrocarbon receptor (AhR) has been studied as an intracellular pattern recognition receptor that can identify bacterial pigments. To identify a potential therapeutic target for periodontitis, we investigated the expression of AhR in periodontitis and its role in the pathogenesis of periodontitis. Methods: First, we analyzed AhR expression in a single-cell dataset from human periodontal tissue. Quantitative polymerase chain reaction (qPCR), immunofluorescence, and immunohistochemistry were used to verify the AhR level. Later, we determined the phenotypes of ligature-induced periodontitis in myeloid-specific AhR-deficient mice (Lyz2-Cre(+/-) AhR(fx/fx)), after which RNA sequencing (RNA-seq), qPCR, Western blot, immunofluorescence, and immunohistochemistry were used to investigate the impacts of AhR on periodontitis and its mechanism. Finally, we determined the therapeutic effect of AhR agonist 6-Formylindolo[3,2-b]carbazole (FICZ) administration on murine periodontitis and verified the effects of FICZ on macrophage polarization in vitro. Results: AhR expression was enhanced in macrophages from periodontitis patients. Deletion of AhR from macrophages aggravated ligature-induced periodontitis and promoted the inflammatory response. Calcium/calmodulin-stimulated protein kinase II (CaMKII) phosphorylation was accelerated in AhR-deficient macrophages. Inhibiting CaMKII phosphorylation ameliorated periodontitis in Lyz2-Cre(+/-) AhR(fx/fx) mice. FICZ treatment blocked alveolar bone loss and relieved periodontal inflammation. FICZ diminished M1 macrophage polarization and promoted M2 macrophage polarization upon M1 macrophage induction. Conclusion: AhR played a protective role in the pathogenesis of periodontitis by orchestrating macrophage polarization via interacting with the CaMKII signaling pathway.

关键词： aryl hydrocarbon receptor CaMKII macrophage pattern recognition receptor periodontitis

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Pioneering Insights into the Reaction Kinetics of Metastable Intermolecular Composites Based on Metal Fluorides: Virtually non-existent condensed Phase Combustion Products and Ultra-Efficient Reactivity

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ADVANCED SCIENCE 2025年第14期12卷 e2415073页

作者： Liu, xuwen Li, Jingwei feng, Shenghua Jia, Yongsheng Hu, Maocong Yao, Yingkang Sun, Jinshan Xie, Quanmin Sang, Hongqian Jianghan Univ State Key Lab Precis Blasting Wuhan 430113 Peoples R China Jianghan Univ Hubei Key Lab Blasting Engn Wuhan 430056 Peoples R China Anhui Univ Sci & Technol Sch Chem & Blasting Engn Huainan 232001 Peoples R China Jianghan Univ Sch Optoelect Mat & Technol Wuhan 430056 Peoples R China

As a typical representative of Metastable intermolecular composites (MICs), the energy release of nano-thermites relying on aluminum-oxygen reaction is limited by the formation of high boiling point condensed phase products. Low pressure output performance constitutes another pivotal factor influencing their efficacy. In this work, metal fluorides BiF3 at different scales were incorporated into nano-thermites as oxidants, thereby facilitating the tunability of the released energy. The boiling points of all resultant reaction products fall below the combustion temperature, theoretically abolishing the agglomeration of condensed-phase products, thus preventing the entrapment of active metals. Additionally, it facilitates the smooth conduction of heat flux, thereby averting losses in biphasic flow dynamics. The n-Al/n-BiF3 system exhibits a significant amplification in reactive kinetic properties in stark contrast to the n-Al/n-Bi2O3 system. The reduction in ignition threshold is ascribed to a novel reaction kinetics mechanism within the n-Al/BiF3 system. The highly electronegative fluorine within BiF3 corrodes the Al2O3 shell, inducing a "pre-ignition" reaction. The application of Density Functional Theory (DFT) evaluations has further corroborated the n-Al/n-BiF3 system's preeminence in electron transfer capacity between the oxidizing agent and fuel, thereby furnishing an molecular-electronic basis for its potent reactive kinetic properties.

关键词： combustion mechanism metal fluorides metastable intermolecular composites nanostructured energetic materials pre-ignition reactions

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