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Simulation of the Power Take-off System for a Heaving Buoy Wave Energy Converter

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Journal of Ocean University of China 2020年第3期19卷 497-504页

作者： CAO Feifei SHI Hongda LI Ming dong Xiaochen LI Demin College of Engineering Ocean University of ChinaQingdao 266100China Shandong Provincial Key Laboratory of Ocean Engineering Qingdao 266100China Qingdao Municipal Key Laboratory of Ocean Renewable Energy Qingdao 266100China

The heaving buoy wave energy device is popular for wave conditions with small wave heights and short periods. This paper presents the design of a wave energy converter composed of a gyro buoy, a hydraulic power take-off, and an electricity generation system. The energy accumulators are used to improve the output power with different control strategies. The quantity relations between each component are established using theoretical methods. The simulation model describes the energy conversion and calculates the operation time, energy capacity, and output power of the device under different initial pressures, release pressures, and electric resistances. As a result, the capacity is determined by the electronic load, and the maximum output power can be obtained when the accumulators are turned on and off at the same time. This study investigates the factors influencing the electric energy production and can be used to guide the optimization of this type of device.

关键词： wave energy heaving buoy power-take-off accumulator output power

Comparison of potential potassium leaching associated with organic and inorganic potassium sources in different arable soils in China

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Pedosphere 2022年第2期32卷 330-338页

作者： Dianjun LU Yanhong dong Xiaoqin CHEN Huoyan WANG Jianmin ZHOU State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China Soil and Fertilizer Station of Shandong Province Jinan 250100China

Potassium (K) leaching is detrimental to the maintenance of sustainable arable soil K fertility,especially in low-K fixation *** is not known whether the application of inorganic fertilizers with lower K mobility or crop straw can reduce potential K leaching in low-K fixation arable *** potential K leaching of 14 representative arable soils with different K fixation capacities in China was evaluated with or without the addition of K under two rainfall intensities (90 and 225 mm),and then potential K leaching was assessed in relation to five K sources (KCl,K_(2)SO_(4),KH_(2)PO_(4),maize (Zea mays L.) straw,and rice (Oryza sativa L.) straw).Without K addition,K leaching mainly occurred in sandy soils at 90 mm of rainfall and in soils with greater organic matter at225 mm of *** K addition,the leaching percentage of exogenous K ranged from 0.6%to 11.6%at 90 mm of rainfall and 1.2%to 21.2%at 225 mm of *** greatest K leaching occurred in soils with fewer K-bearing minerals and lower pH at both rainfall *** most cases,KH_(2)PO_(4),which has lower K mobility,markedly reduced K leaching in both high-and low-K leaching soils at the two rainfall *** and rice straw reduced K leaching only in soils with high K leaching,regardless of rainfall amount,whereas more K was leached in soils with lower K leaching at high rainfall *** conclusion,KH_(2)PO_(4) and straw should be preferred for reducing K leaching in low-K fixation arable soils.

关键词： crop straw K-bearing mineral K fixation K source soil type

A Disulfide-Based Poly(ether-b-amide)Copolymer with Rapid Self-healing Ability under Moderate Conditions

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Chinese Journal of Chemistry 2024年第9期42卷 943-950页

作者： Weijan Lu ping Zhu Ying Zhao Dujin Wang Xia dong Institute of Chemistry Chinese Academy of SciencesBeijing 100190China Schoolof Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China

Comprehensive Summary A disulfide-based poly(ether-b-amide)copolymer with rapid self-healing capability under moderate conditions was synthesized from 4,4’-dithiodibutyric acid(DTDBA),isophorondiamine(IPDA)and poly(tetramethylene oxide)(PTMO)based on a two-step *** incorporation of IPDA with asymmetric structure and substantial steric hindrance not only effectively decreased the number of regular H-bonds,but also inhibited the crystallization of polyamide segments,imparting the synthesized poly(ether-b-amide)copolymer with an amorphous structural *** on the coordination of segmental diffusion and recombination of disulfide bonds and hydrogen bonds,the scratches and damaged mechanical properties of PEBADS-I611 could be completely self-healed after healing at 40°C for only 11 min and 3 h,respectively.

关键词： Poly(ether-b-amide)copolymer Disulfide bonds Hydrogen bonds Polycondensation Smart polymers Self-healing

Long-term Visual Tracking: Review and Experimental Comparison

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Machine Intelligence Research 2022年第6期19卷 512-530页

作者： Chang Liu Xiao-Fan Chen Chun-Juan Bo dong Wang School of Information and Communication Engineering Dalian University of TechnologyDalian 116024China Dalian Minzu University Dalian 116600China

As a fundamental task in computer vision,visual object tracking has received much attention in recent *** studies focus on short-term visual tracking which addresses shorter videos and always-visible ***,long-term visual tracking is much closer to practical applications with more complicated *** exists a longer duration such as minute-level or even hour-level in the long-term tracking task,and the task also needs to handle more frequent target disappearance and *** this paper,we provide a thorough review of long-term tracking,summarizing long-term tracking algorithms from two perspectives:framework architectures and utilization of intermediate tracking *** we provide a detailed description of existing benchmarks and corresponding evaluation ***,we conduct extensive experiments and analyse the performance of trackers on six benchmarks:VOTLT2018,VOTLT2019(2020/2021),OxUvA,LaSOT,TLP and the long-term subset of ***,we discuss the future prospects from multiple perspectives,including algorithm design and benchmark *** our knowledge,this is the first comprehensive survey for long-term visual object *** relevant content is available at https://***/wangdongdut/Long-term-Visual-Tracking.

关键词： Visual object tracking long-term tracking short-term tracking re-detection online update

Ecological effect of the plantation of Sabina vulgaris in the Mu Us Sandy Land,China

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Journal of Arid Land 2024年第1期16卷 14-28页

作者： NAN Weige dong Zhibao ZHOU Zhengchao LI Qiang CHEN Guoxiang School of Geography and Tourism Shaanxi Normal UniversityXi'an 710062China Shaanxi Key Laboratory of Ecological Restoration in Shaanbei Mining Area Yulin UniversityYulin 719000China College of Prataculture Gansu Agricultural UniversityLanzhou 730070China

Vegetation restoration through artificial plantation is an effective method to combat desertification,especially in arid and semi-arid *** study aimed to explore the ecological effect of the plantation of Sabina vulgaris on soil physical and chemical properties on the southeastern fringe of the Mu Us Sandy Land,*** collected soil samples from five depth layers(0-20,20-40,40-60,60-80,and 80-100 cm)in the *** plantation plots across four plantation ages(4,7,10,and 16 years)in November 2019,and assessed soil physical(soil bulk density,soil porosity,and soil particle size)and chemical(soil organic carbon(SOC),total nitrogen(TN),available nitrogen(AN),available phosphorus(AP),available potassium(AK),cation-exchange capacity(CEC),salinity,p H,and C/N ratio)*** results indicated that the soil predominantly consisted of sand particles(94.27%-99.67%),with the remainder being silt and *** plantation age increased,silt and very fine sand contents progressively *** 16 years of planting,there was a marked reduction in the mean soil particle *** initial soil fertility was low and declined from 4 to 10 years of planting before witnessing an *** positive correlations were observed for the clay,silt,and very fine sand(mean diameter of 0.000-0.100 mm)with SOC,AK,and p *** contrast,fine sand and medium sand(mean diameter of 0.100-0.500 mm)showed significant negative correlations with these *** findings ascertain that the plantation of *** requires 10 years to effectively act as a windbreak and contribute to sand fixation,and needs 16 years to improve soil physical and chemical ***,these improvements were found to be highly beneficial for vegetation restoration in arid and semi-arid *** research can offer valuable insights for the protection and restoration of the vegetation ecosystem in the sandy lands in China.

关键词： Sabina vulgaris plantation age soil physical and chemical properties soil particle size soil fertility vegetation restoration Mu Us Sandy Land

An update on the function and regulation of methylerythritol phosphate and mevalonate pathways and their evolutionary dynamics

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Journal of Integrative Plant Biology 2021年第7期63卷 1211-1226页

作者： Xiaojun Pu Xiumei dong Qing Li Zexi Chen Li Liu State Key Laboratory of Biocatalysis and Enzyme Engineering Hubei Collaborative Innovation Center for Green Transformation of BioResourcesHubei Key Laboratory of Industrial BiotechnologySchool of Life SciencesHubei UniversityWuhan 434200China Key Laboratory for Economic Plants and Biotechnology Kunming Institute of Botanythe Chinese Academy of Sciencesand Yunnan Key Laboratory for Wild Plant ResourcesKunming 650201China School of Life Sciences Yunnan UniversityKunming 650091China University of the Chinese Academy of Sciences Beijing 100049China

Isoprenoids are among the largest and most chemically diverse classes of organic compounds in nature and are involved in the processes of photosynthesis, respiration, growth, development,and plant responses to stress. The basic building block units for isoprenoid synthesis-isopentenyl diphosphate and its isomer dimethylallyl diphosphate-are generated by the mevalonate (MVA) and methylerythritol phosphate(MEP) pathways. Here, we summarize recent advances on the roles of the MEP and MVA pathways in plant growth, development and stress responses, and attempt to define the underlying gene networks that orchestrate the MEP and MVA pathways in response to developmental or environmental *** phylogenomic analysis, we also provide a new perspective on the evolution of the plant isoprenoid pathway. We conclude that the presence of the MVA pathway in plants may be associated with the transition from aquatic to subaerial and terrestrial environments, as lineages for its core components are absent in green algae. The emergence of the MVA pathway has acted as a key evolutionary event in plants that facilitated land colonization and subsequent embryo development, as well as adaptation to new and varied environments.

关键词： evolutionary innovation MEP pathway MVA pathway retrograde signaling stress

Institutional environment and risk of a stock price crash:evidence from China

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China Finance and Economic Review 2015年第3期4卷 40-66页

作者： Li Xiaorong dong Hongye School of Public Finance Central University of Finance and EconomicsBeijingChina Renmin University of China BeijingChina

Stock price crashes damage China’s macro-financial stability,restrict economic growth,and can lead to huge losses in wealth for ***,how to reduce the risk for stock price crashes is an important theoretical and practical *** paper mainly studies the effects of the institutional environment that creates risks for stock price *** China’s non-financial A-share listed companies from 1997 to 2012 as an example,this paper finds that the lower the level of government intervention is,the better the legal environment is,the faster the market process in business area is,then the lower the risks for stock price crashes will *** solve the endogenous problem between the institutional environment and the risk of a stock price crash,this paper uses the number of seaports and whether the commercial ports or leased territories are opened after the first Opium War in Qing Dynasty as instrumental variables of the institutional *** find that the above conclusion is still valid with the method of 2SLS ***,this paper also finds that the government intervention index,the legal environment index,and the market index are negatively related to stock price synchronicity to a significant *** conclusions illustrate that the institutional environment is an important factor in the healthy and stable development of the capital market,which has important implications for policy markers or regulators to develop policies to promote the stable development of the stock market,to control market risk of listed companies,and to make investment decisions.

关键词： institutional environment capital market stock price crash risk stock price synchronicity

A Novel Radish Phospholipid Hydroperoxide Glutathione Peroxidase Is Located in Mitochondria

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Acta Genetica Sinica 2004年第9期31卷 1010-1011页

作者： YANGXiao-dong LIUJin-Yuan LaboratoryofMolecularBiologyandMOELaboratoryofProteinScience DepartmentofBiologicalSciencesandBiotechnologyTsinghuaUniversityBeijing100084China

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is a unique antioxidative enzyme which specifically catalyses the reduction of phospholipid hydroperoxides so as to protect biomembrane from oxidative injury. ... 详细信息

关键词：萝卜磷脂过氧化氢化物谷胱甘肽过氧化酶线粒体 PHGPx 抗氧化酶

What and where: A context-based recommendation system for object insertion

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Computational Visual Media 2020年第1期6卷 79-93页

作者： Song-Hai Zhang Zheng-Ping Zhou Bin Liu Xi dong Peter Hall Tsinghua University Beijing 100084China Beijing National Research Center for Information Science and Technology(BNRist) Tsinghua UniversityBeijing 100084China Department of Computer Science Media Technology Research Center University of BathBath BA27AYUK

We propose a novel problem revolving around two tasks:(i)given a scene,recommend objects to insert,and(ii)given an object category,retrieve suitable background scenes.A bounding box for the inserted object is predicted in both tasks,which helps downstream applications such as semiautomated advertising and video *** major challenge lies in the fact that the target object is neither present nor localized in the input,and furthermore,available datasets only provide scenes with existing *** tackle this problem,we build an unsupervised algorithm based on object-level contexts,which explicitly models the joint probability distribution of object categories and bounding boxes using a Gaussian mixture *** on our own annotated test set demonstrate that our system outperforms existing baselines on all sub-tasks,and does so using a unified *** extensions and applications are suggested.

关键词： object recommendation bounding box prediction image composition object-level context