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The effect of Typhoon Kalmaegi on the modal energy and period of internal waves near the Dongsha Islands(South China Sea)

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Acta Oceanologica Sinica 2023年第12期42卷 22-31页

作者： Rongwei Zhai Guiying Chen Chenjing Shang Xiaodong Shang Youren Zheng South China Sea Information Center of State Oceanic Administration Guangzhou 510310China State key laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510315China shenzhen key laboratory of marine Bioresource and Eco-environmental Science College of Life Sciences and OceanographyShenzhen UniversityShenzhen 518060China

The influence of Typhoon Kalmaegi on internal waves near the Dongsha Islands in the northeastern South China Sea was investigated using mooring observation data.We observed,for the first time,that the phenomenon of regular variation characteristics of the 14-d spring-neap cycle of diurnal internal tides(ITs)can be regulated by typhoons.The diurnal ITs lost the regular variation characteristics of the 14-d spring-neap cycle during the typhoon period owing to the weakening of diurnal coherent ITs,represented by O_(1)and K_(1),and the strengthening of diurnal incoherent ITs.Results of quantitative analysis showed that during the pre-typhoon period,timeaveraged modal kinetic energy(sum of Modes 1–5)of near-inertial internal waves(NIWs)and diurnal and semidiurnal ITs were 0.62 kJ/m^(2),5.66 kJ/m^(2),and 1.48 kJ/m^(2),respectively.However,during the typhoon period,the modal kinetic energy of NIWs increased 5.11 times,mainly due to the increase in high-mode kinetic energy.At the same time,the modal kinetic energy of diurnal and semidiurnal ITs was reduced by 68.9%and 20%,respectively,mainly due to the decrease in low-mode kinetic energy.The significantly reduced diurnal ITs during the typhoon period could be due to:(1)strong nonlinear interaction between diurnal ITs and NIWs,and(2)a higher proportion of high-mode diurnal ITs during the typhoon period,leading to more energy dissipation.

关键词： internal waves spring-neap cycle modal kinetic energy South China Sea

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siRNA-mediated DNA methylation and H3K9 dimethylation in plants

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Protein & Cell 2013年第9期4卷 656-663页

作者： Chi Xu Jing Tian Beixin Mo College of Life Science Shenzhen Key Laboratory of Microbial Genetic EngineeringShenzhen UniversityShenzhen 518060China College of Life Science Shenzhen Key Laboratory of Marine Biological Resources and Ecological EnvironmentShenzhen UniversityShenzhen 518060China

Heterochromatic siRNAs regulate transcriptional gene silencing by inducing DNA methylation and histone H3K9 dimethylation.Recent advances have revealed the distinct phases involved in siRNA mediated silencing pathway,although the precise functions of a number of factors remain undesignated,putative mechanisms for the con-nection between DNA and histone methylation have been investigated,and much effort has been invested to understand the biological functions of siRNA-mediated epigenetic modifi cation.In this review,we summarize the mechanism of siRNA-mediated epigenetic modification,which involves the production of siRNA and the recruit-ments of DNA and histone methytransferases to the target sequences assisted by complementary pairing between 24-nt siRNAs and nascent scaffold RNAs,the roles of siRNA-mediated epigenetic modifi cation in maintaining genome stability and regulating gene expression have been dis-cussed,newly identified players of the siRNA mediated silencing pathway have also been introduced.

关键词： epigenetic DNA methylation histone meth-ylation heterochromatic siRNA argonaute

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Antioxidant xanthones and anthraquinones isolated from a marine-derived fungus Aspergillus versicolor

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Chinese Journal of Natural Medicines 2018年第3期16卷 219-224页

作者： WU Ze-Hong LIU Dong XU Ying CHEN Jian-Liang LIN Wen-Han The Eighth Affiliated Hospital Sun Yat-sen University State key laboratory of Natural and Biomimetic Drugs Peking University shenzhen key laboratory of marine Bioresource & Eco-environmental Science Shenzhen Engineering Laboratory for Marine Algal Biotechnology College of Life Science Shenzhen University

Chemical examination of an EtO Ac extract of cultured Aspergillus versicolor fungus from deep-sea sediments resulted in the isolation of four xanthones, eight anthraquinones and five alkaloids, including a new xanthone, oxisterigmatocystin D(1) and a new alkaloid, aspergillusine A(13). High resolution electron impact mass spectrometry(HR-EI-MS), FT-IR spectroscopy, and NMR techniques were used to elucidate the structures of these compounds, and the absolute configuration of compound 1 was established by its NMR features and coupling constant. Furthermore, the biosynthesis pathway of these xanthones and anthraquinones were deduced, and their antioxidant activity and cytotoxicity in human cancer cell lines(HTC-8, Bel-7420, BGC-823, A549, and A2780) were evaluated. The trolox equivalent antioxidant capacity(TEAC) assay indicated most of the xanthones and anthraquinones possessing moderate antioxidant activities. The Nrf2-dependent luciferase reporter gene assay revealed that compounds 6, 7, 9, and 12 potentially activated the expression of Nrf2-regulated gene. In addition, compounds 5 and 11 showed weak cytotoxicity on A549 with the IC50 values of 25.97 and 25.60 μmol×L^(–1), respectively.

关键词：曲霉属菌多色氧杂蒽酮 Anthraquinones 抗氧化剂活动 Cytotoxicity

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A low-carbon strategy for revival of degraded single crystal LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)

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Rare Metals 2023年第2期42卷 459-470页

作者： Kai Yuan Rui-Qi Ning Li-Jiao Zhou Chao Shen Si-Si Zhou Jing Li Ting Jin Xiang-Gong Zhang Ke-Yu Xie State key laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an710072China Wuhan Institute of marine Electric Propulsion China Shipbuilding Industry CorporationWuhan430064China Research and Development Institute of Northwestern Polytechnical University in shenzhen Northwestern Polytechnical UniversityShenzhen518057China State key laboratory of Environment-Friendly Energy Materials School of Material Science and EngineeringSouthwest University of Science and TechnologyMianyang621010China

Single crystal LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)is currently widely used due to the outstanding cycle stability and safety.However,its sensitivity to the environment and the high residual alkali makes the electrochemical performance and processing property severely degraded after long-term storage,especially for the Ni-rich single crystal material.Therefore,it is highly urgent to develop a cost-effective strategy for the revival of degraded Ni-rich cathode materials.Here,a low-carbon strategy is proposed to revive the degraded single crystal LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(SCNCM622)through water washing.The solid-liquid reaction mechanism of SCNCM622 and water was revealed and the strong dependence of the recovery effect on the washing time was clarified.Under optimized conditions,the sample with a washing time of 24 h shows 31.2%reduction in viscosity,18.4%improvement in discharge capacity,15.3%enhancement in cycle life,and excellent rate performance compared to the blank sample.Therefore,this strategy can achieve higher utilization of single crystal Ni-based cathode materials with a lower cost.

关键词： Li-ion battery Ni-rich cathode materials Single crystal LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2) Water washing Electrochemical performance

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A Cooperative Security Monitoring Mechanism Aided by Optimal Multiple Slave Cluster Heads for UASNs

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China Communications 2023年第5期20卷 148-169页

作者： Yougan Chen Wei Wang Xiang Sun Yi Tao Zhenwen Liu Xiaomei Xu key laboratory of Underwater Acoustic Communication and marine Information Technology Xiamen UniversityXiamen 361005China shenzhen Research Institute of Xiamen University Shenzhen 518000China Dongshan Swire marine Station College of Ocean and Earth SciencesXiamen UniversityXiamen 361102China State key laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China Department of Electrical and Computer engineering University of New MexicoAlbuquerqueNM 87131USA College of Harbour and Coastal engineering Jimei UniversityXiamen 361021China

As each cluster head(CH)sensor node is used to aggregate,fuse,and forward data from different sensor nodes in an underwater acoustic sensor network(UASN),guaranteeing the data security in a CH is very critical.In this paper,a cooperative security monitoring mechanism aided by multiple slave cluster heads(SCHs)is proposed to keep track of the data security of a CH.By designing a low complexity“equilateral triangle algorithm(ETA)”,the optimal SCHs(named as ETA-based multiple SCHs)are selected from the candidate SCHs so as to improve the dispersion and coverage of SCHs and achieve largescale data security monitoring.In addition,by analyzing the entire monitoring process,the close form expression of the probability of the failure attack identification for the SCHs with respect to the probability of attack launched by ordinary nodes is deduced.The simulation results show that the proposed optimal ETA-based multiple SCH cooperation scheme has lower probability of the failure attack identification than that of the existing schemes.In addition,the numerical simulation results are consistent with the theoretical analysis results,thus verifying the effectiveness of the proposed scheme.

关键词： underwater acoustic sensor networks data security cluster head nodes optimal location distribution of multiple slave cluster head nodes

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Coastal blue carbon in China as a nature-based solution toward carbon neutrality

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The Innovation 2023年第5期4卷 109-123页

作者： Faming Wang Jihua Liu Guoming Qin Jingfan Zhang Jinge Zhou Jingtao Wu Lulu Zhang Poonam Thapa Christian J.Sanders Isaac R.Santos Xiuzhen Li Guanghui Lin Qihao Weng Jianwu Tang Nianzhi Jiao Hai Ren Xiaoliang Research Station of Tropical Coastal Ecosystems Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystemsand the CAS Engineering Laboratory for Ecological Restoration of lsland and Coastal EcosystemsSouth China Botanical GardenChinese Academy of SciencesGuangzhou 510650China Southern marine Science and engineering Guangdong laboratory(Guangzhou) Guangzhou 510650China marine Research Institute Shandong UniversityQingdao 266237China University of Chinese Academy of Sciences Beijing 100049China National marine Science Centre Faculty of Science and EngineeringSouther Cross UniversityCoffs HarbourNSW 2450Australia Department of marine Sciences University of Gothenburg41319 GothenburgSweden State key laboratory of Estuarine and Coastal Research and Instiute of Eco-Chongming East China Normal UniversityShanghai 201100China key laboratory for Earth System Modeling Ministry of EducationDepartment of Earth System ScienceTsinghua UniversityBejing 100084China laboratory of Stable Isotope and Gulf Ecology Institute of Ocean EngineeringTsinghua's Shenzhen International Graduate SchoolShenzhen 518055China Department of Land Surveying and Geo-nformatics The Hong Kong Polytechnic UniversiyHongkong 99077China Innovative Research Center for Carbon Neutralization Global ONCE ProgramXiamen 361005China

To achieve the Paris Agreement,China pledged to become“Carbon Neutral”by the 2060s.In addition to massive decarbonization,this would require significant changes in ecosystems toward negative CO_(2)emissions.The ability of coastal blue carbon ecosystems(BCEs),including mangrove,salt marsh,and seagrass meadows,to sequester large amounts of CO_(2)makes their conservation and restoration an important“nature-based solution(NbS)”for climate adaptation and mitigation.In this review,we examine how BCEs in China can contribute to climate mitigation.On the national scale,the BCEs in China store up to 118 Tg C across a total area of 1,440,377 ha,including over 75%as unvegetated tidal flats.The annual sedimental C burial of these BCEs reaches up to 2.06 Tg C year^(−1),of which most occurs in salt marshes and tidal flats.The lateral C flux of mangroves and salt marshes contributes to 1.17 Tg C year^(−1)along the Chinese coastline.Conservation and restoration of BCEs benefit climate change mitigation and provide other ecological services with a value of$32,000 ha^(−1)year^(−1).The potential practices and technologies that can be implemented in China to improve BCE C sequestration,including their constraints and feasibility,are also outlined.Future directions are suggested to improve blue carbon estimates on aerial extent,carbon stocks,sequestration,and mitigation potential.Restoring and preserving BCEs would be a cost-effective step to achieve Carbon Neutral by 2060 in China despite various barriers that should be removed.

关键词： tidal coastal carbon

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Recent development of nanomaterials for carbon dioxide electroreduction

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SmartMat 2022年第1期3卷 35-53页

作者： Jianjun Su Yong Liu Yun Song Libei Huang Weihua Guo Xiaohu Cao Yubing Dou Le Cheng Geng Li Qiushi Hu Ruquan Ye Department of Chemistry State Key Laboratory of Marine PollutionCity University of Hong KongHong KongChina City University of Hong Kong shenzhen Research Institute ShenzhenChina

Electrochemical CO_(2) reduction reaction(CO_(2)RR)to produce value‐added products has received tremendous research attention in recent years.With research efforts across the globe,remarkable advancement has been achieved,including the improvement of selectivity for the reduction products,the realization of efficient reduction beyond two electrons,and the delivery of industrially relevant current densities.In this review,we introduce the recent development of nanomaterials for CO_(2)RR,including the zero‐dimensional graphene quantum dots,two‐dimensional materials such as metal chalcogenides and metal/covalent organic framework,singleatom catalysts,and nanostructured metal catalysts.The engineering of materials into three‐dimensional structure will also be discussed.Finally,we will provide a summary of the catalytic performance and perspectives on future development.

关键词： CO_(2)reduction graphene quantum dots metal chalcogenides multielectrons products nanostructured metals single‐atom catalysts

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Evaluation of the submarine debris-flow hazard risks to planned subsea pipeline systems: a case study in the Qiongdongnan Basin, South China Sea

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Acta Oceanologica Sinica 2023年第5期42卷 139-153页

作者： Mingquan Huang Xuesheng Qian Jingping Xu Xuecheng Li School of Environment Harbin Institute of TechnologyHarbin 150001China Department of Ocean Science and engineering Southern University of Science and TechnologyShenzhen 518055China Southern marine Science and engineering Guangdong laboratory(Guangzhou) Guangzhou 511458China China Offshore Fugro Geosolutions(shenzhen)Corporation Limited Shenzhen 518067China

The ever-increasing deepwater oil and gas development in the Qiongdongnan Basin,South China Sea has initiated the need to evaluate submarine debris-flow hazard risks to seafloor infrastructures.This paper presents a case study on evaluating the debris-flow hazard risks to the planned pipeline systems in this region.We used a numerical model to perform simulations to support this quantitative evaluation.First,one relict failure interpreted across the development site was simulated.The back-analysis modeling was used to validate the applicability of the rheological parameters.Then,this model was applied to forecast the runout behaviors of future debris flows originating from the unstable upslope regions considered to be the most critical to the pipeline systems surrounding the Manifolds A and B.The model results showed that the potential debris-flow hazard risks rely on the location of structures and the selection of rheological parameters.For the Manifold B and connected pipeline systems,because of their remote distances away from unstable canyon flanks,the potential debris flows impose few risks.However,the pipeline systems around the Manifold A are exposed to significant hazard risks from future debris flows with selected rheological parameters.These results are beneficial for the design of a more resilient pipeline route in consideration of future debris-flow hazard risks.

关键词： submarine debris flow pipeline manifold hazard evaluation route optimization Qiongdongnan Basin

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Frictional sliding of infilled planar granite fracture under oscillating normal stress

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International Journal of Mining Science and Technology 2023年第6期33卷 687-701页

作者： Kang Tao Wengang Dang Yingchun Li School of Civil engineering Sun Yat-sen UniversityZhuhai 519086China State key laboratory of Coal Resources and Safe Mining China University of Mining and TechnologyXuzhou 221116China Southern marine Science and engineering Guangdong laboratory Zhuhai 519086China State key laboratory of Coastal and Offshore engineering Dalian University of TechnologyDalian 116024China

This paper investigates the frictional behavior of the infilled rock fracture under dynamic normal stress.A series of direct shear tests were conducted on saw-cut granite fractures infilled with quartz using a selfdeveloped dynamic shear apparatus,and the effects of normal load oscillation amplitude,normal load oscillation period and sliding velocity were studied.The test results reveal that the shear response can be divided into three stages over a whole loading-unloading process,characterized by different time spans and stress variations.Generally,a smaller oscillation amplitude,a longer oscillation period and a fast shear velocity promote the stability of the friction system,which is also confirmed by the Coulomb failure criterion calculated based on the observed periodic apparent friction coefficient.The dynamic strengthening/weakening phenomenon is dependent on the oscillation amplitude and product of sliding velocity and oscillation period(vT).Also,the rate and state friction law incorporating the parameter a that characterizes the normal stress variation is employed to describe the dynamic friction coefficient but exhibits an incompetent performance when handling intensive variation in normal stress.Finally,the potential seismicity induced by oscillating normal stress based on the observed stress drop is analyzed.This work helps us understand the sliding process and stability evolution of natural faults,and its benefits for relative hazard mitigation.

关键词： Granite fracture Quartz gouge Normal load oscillation Frictional stability Rate and state friction law

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Rational design of copper-based single-atom alloy catalysts for electrochemical CO_(2)reduction

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Nano Research 2022年第8期15卷 7116-7123页

作者： Jian-Chao Jiang Jun-Chi Chen Meng-die Zhao Qi Yu Yang-Gang Wang Jun Li School of Materials Science and engineering and Shaanxi Laboratory of CatalysisShaanxi University of TechnologyHanzhong 723001China Department of Chemistry and Guangdong Provincial key laboratory of Catalysis Southern University of Science and TechnologyShenzhen 518055China Department of Chemistry and key laboratory of Organic Optoelectronics&Molecular engineering of Ministry of Education Tsinghua UniversityBeijing 100084China

Electrochemical CO_(2)-reduction reaction(CO_(2)RR)is a promising way to alleviate energy crisis and excessive carbon emission.The Cu-based electrocatalysts have been considered for CO_(2)RR to generate hydrocarbons and alcohols.However,the application of Cu electrocatalysts has been restricted by a high onset potential for CO_(2)RR and low selectivity.In this study,we have designed a series of Cu-based single-atom alloy catalysts(SAAs),denoted as TM1/Cu(111),by doping isolated 3dtransition metal(TM)atom onto the Cu(111)surface.We theoretically evaluated their stability and investigated the activity and selectivity toward CO_(2)RR.Compared to the pure Cu catalyst,the majority TM1/Cu(111)catalysts are more favorable for hydrogenating CO_(2)and can efficiently avoid the hydrogen-evolution reaction due to the strong binding of carbonaceous intermediates.Based on the density functional theory calculations,instead of the HCOOH or CO products,the initial hydrogenation of CO_(2)on SAAs would form the*CO intermediate,which could be further hydrogenated to produce methane.In addition,we have identified the bond angle of adsorbed*CO_(2)can describe the CO_(2)activation ability of TM1/Cu(111)and the binding energy of*OH can describe the CO_(2)RR activity of TM1/Cu(111).We speculated that the V/Cu(111)can show the best activity and selectivity for CO_(2)RR among all the 3d-TM-doped TM1/Cu(111).This work could provide a rational guide to the design of new type of single-atom catalysts for efficient CO_(2)RR.

关键词： CO_(2)electrochemical reduction Cu single-atom alloy catalysts density functional theory

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