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Gossip-Based Resource Location Strategy in Interest Community for P2P Networks

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Chinese Journal of Electronics 2015年第2期24卷 272-280页

作者： HE Ming zhang yujie MENG Xiangwu School of Computer Science Beijing University of Posts and Telecommunications Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia

Resource location strategy has become very popular for mass data distribution in complex and dynamic network. Searching for the objects is a fundamental problem to unstructured Peer to peer(P2P) networks. In this paper, we propose a resource location strategy for user requirements, which employs the collaborative exchange of information between peers to construct interest communities. This strategy can gather similar peers and disseminate useful information among them. Furthermore, we design an algorithm in unstructured P2 P systems named Appropriate degree gossip search algorithm(ADGSA). Using this search algorithm, the performance including search success ratio, recall rate and search response time has been improved dramatically. An efficient resource location system with a fast organization of users cluster based on their requirements can be provided, preventing the creation of unliked communities. The simulation results show that our strategy has better search efficiency, short response time and high recall ratio.

关键词： Unstructured P2P network Resource location Interest community Gossip-based search Flooding

An Adaptive User Preferences Elicitation Scheme for Location Recommendation

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Chinese Journal of Electronics 2016年第5期25卷 943-949页

作者： WANG Fan MENG Xiangwu zhang yujie Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia School of Computer Science Beijing University of Posts and Telecommunications

User preferences elicitation is a key issue of location recommendation. This paper proposes an adaptive user preferences elicitation scheme based on Collaborative filtering(CF) algorithm for location recommendation. In this scheme, user preferences are divided into user static preferences and user dynamic preferences. The former is estimated based on location category information and historical ratings. Meanwhile, the latter is evaluated based on geographical information and two-dimensional cloud model. The advantage of this method is that it not only considers the diversity of user preferences, but also can alleviate the data sparsity problem. In order to predict user preferences of new locations more precisely, the scheme integrates the similarity of user static preferences, user dynamic preferences and social ties into CF algorithm. Furthermore, the scheme is parallelized on the Hadoop platform for significant improvement in efficiency. Experimental results on Yelp dataset demonstrate the performance gains of the scheme.

关键词： Location recommendation Adaptive User static preferences User dynamic preferences

Microstructure and magnetic properties of Ti/Co/Ti films

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Rare Metals 2006年第Z1期25卷 450-453页

作者： FENG Shunzhen zhang yujie zhang Hanwei SUN Huiyuan College of Physics Science and Information Engineering Hebei Normal University Shijiazhuang 050016 China College of Physics Science and Information Engineering Hebei Normal University Shijiazhuang 050016 China College of Physics Science and Information Engineering Hebei Normal University Shijiazhuang 050016 China College of Physics Science and Information Engineering Hebei Normal University Shijiazhuang 050016 China

The two series of as-deposited and annealed Ti/Co/Ti thin films were deposited by magnetron sputtering onto glass substrates at room temperature. The structural and magnetic properties of the films at room temperature were investigated as function of Co layer thickness. X-ray diffraction (XRD) profiles show Co nanograins are formed as the hexagonal-close-packed (hcp) structure. The perpendicular coercivity of the Ti(15 nm)/Co(30 nm)/Ti(15 nm) film annealed at 450 ℃ for 30 min is about 288 kA·m-1.

关键词： perpendicular magnetic recording coercivity Ti/Co/Ti thin films

Microstructure and magnetic properties of Ti/Ni/Ti in dependence on Ni layer thickness

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Rare Metals 2006年第Z1期25卷 592-595页

作者： zhang Hanwei FENG Shunzhen zhang yujie SUN Huiyuan College of Physics Science and Information Engineering Hebei Normal University Shijiazhuang 050016 China College of Physics Science and Information Engineering Hebei Normal University Shijiazhuang 050016 China College of Physics Science and Information Engineering Hebei Normal University Shijiazhuang 050016 China College of Physics Science and Information Engineering Hebei Normal University Shijiazhuang 050016 China

The films of Ti(15 nm)/Ni(t nm)/Ti(15 nm)(t=20, 30, 40, 50) were prepared by dc magnetron sputtering at room temperature and subsequent annealing at 400 ℃ for 30 min. Scanning probe microscope (SPM), vibrating sample magnetometer (VSM) and X-ray diffraction (XRD) were applied to study the magnetic properties and microstructure. AFM images show that small and uniform grains and some clusters appear with the increase of Ni thickness, also MFM images show that the size of domain first decreases and then increases. The coercivity reaches the maximum 48 kA·m-1 at t=30 nm. The XRD profiles show stronger fcc (111) orientation peak of Ni and weak hcp structure peaks of Ni3Ti. This results reveal that the crystal lines have the prefer orientation and achieve the ordered.

关键词： magnetic recording magnetron sputtering coercivity annealing

Review of the influencing factors of secondary organic aerosol formation and aging mechanism based on photochemical smog chamber simulation methods

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Journal of Environmental Sciences 2023年第1期123卷 545-559页

作者： yujie zhang Miaomiao Cheng Jian Gao Junling Li State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China

The formation and aging mechanism of secondary organic aerosol(SOA)and its influencing factors have attracted increasing attention in recent years because of their effects on climate change,atmospheric quality and human ***,there are still large errors between air quality model simulation results and field *** currently undetected components during the formation and aging of SOA due to the limitation of current monitoring techniques and the interactions among multiple SOA formation influencing factors might be the main reasons for the *** this paper,we present a detailed review of the complex dynamic physical and chemical processes and the corresponding influencing factors involved in SOA formation and *** all these results were mainly based the studies of photochemical smog chamber *** the properties of precursor volatile organic compounds(VOCs),oxidants(such as OH radicals),and atmospheric environmental factors(such as NOx,SO2,NH3,light intensity,temperature,humidity and seed aerosols)jointly influence the products and yield of SOA,the nucleation and vapor pressure of these products were found to be the most fundamental aspects when interpreting the dynamics of the SOA formation and aging *** development of techniques for measuring intermediate species in SOA generation processes and the study of SOA generation and aging mechanism in complex systems should be important topics of future SOA research.

关键词： Secondary organic aerosol Formation and aging mechanism Photochemical smog chamber Volatile organic compounds

Optimizing Bloom Filter Settings for Multi-keyword Search in Kademlia-like DHT Peer-to-Peer Networks

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Chinese Journal of Electronics 2014年第2期23卷 388-393页

作者： MA Wenming zhang yujie MENG Xiangwu School of Computer Science Beijing University of Posts and Telecommunications Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia

This paper has proposed a novel method to reduce the multi-keyword query traffic in Kademlia-like Peer-to-peer(P2P) networks by optimizing the Bloom filter settings. We build some models to estimate the communication cost, the union set size, and the loss rate of performing union and intersection operations. We implement a Kademlia-like system and generate a group of *** use one part of the datasets to obtain the functions how to compute the optimal parameters and use another part of datasets to verify our method. Each query can determine the optimal settings of Bloom filter with no extra configuration. Our simulation experimental results show that with optimal Bloom filters settings, we can greatly reduce the communication cost under an acceptable loss rate.

关键词： Peer-to-peer Bloom filter Multikeyword Kademlia Optimize

Biomacromolecules as carriers in drug delivery and tissue engineering

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Acta Pharmaceutica Sinica B 2018年第1期8卷 34-50页

作者： yujie zhang Tao Sun Chen Jiang Key Laboratory of Smart Drug Delivery Ministry of Education State Key Laboratory of Medical Neurobiology Department of Pharmaceutics School of Pharmacy Fudan University

Natural biomacromolecules have attracted increased attention as carriers in biomedicine in recent years because of their inherent biochemical and biophysical properties including renewability,nontoxicity, biocompatibility, biodegradability, long blood circulation time and targeting ability. Recent advances in our understanding of the biological functions of natural-origin biomacromolecules and the progress in the study of biological drug carriers indicate that such carriers may have advantages over synthetic material-based carriers in terms of half-life, stability, safety and ease of manufacture. In this review, we give a brief introduction to the biochemical properties of the widely used biomacromoleculebased carriers such as albumin, lipoproteins and polysaccharides. Then examples from the clinic and in recent laboratory development are summarized. Finally the current challenges and future prospects of present biological carriers are discussed.

关键词： Biomacromolecule Protein Polysaccharide Drug delivery Tissue engineering

Research progress and mechanism of nanomaterials-mediated in-situ remediation of cadmium-contaminated soil:A critical review

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Journal of Environmental Sciences 2021年第6期33卷 351-364页

作者： Yuenan zhang yujie zhang Ozioma Udochukwu Akakuru Xiawei Xu Aiguo Wu Cixi Institute of Biomedical Engineering Chinese Academy of Science(CAS)Key Laboratory of Magnetic Materials and Devices&Zhejiang Engineering Research Center for Biomedical MaterialsNingbo Institute of Materials Technology and EngineeringCAS NingboNingbo 315201China University of Chinese Academy of Sciences Beijing 100049China

Cadmium contamination of soil is a global issue and in-situ remediation technology as a promising mitigation strategy has attracted more and more *** nanomaterials have been applied for the in-situ remediation of cadmium-contaminated soil due to their excellent properties of the nano-scale size *** this work,recent research progress of various nanomaterials,including carbon nanomaterials,metal-based nanomaterials and nano mineral materials,in the removal of cadmium and in-situ remediation of cadmiumcontaminated soil were systematically *** emphases were particularly laid on both laboratory and field restoration ***,the factors which can affect the stability of cadmium,main interaction mechanisms between nanomaterials and cadmium in the soil,and potential future research direction were also ***,it is believed that this work will ultimately contribute to the myriad of environmental cleanup advances,and further improve human health and sustainable development.

关键词： Cadmium pollution Contaminated soil In-situ remediation Mechanism Nanomaterials

Levels,sources and health risks of carbonyls and BTEX in the ambient air of Beijing,China

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Journal of Environmental Sciences 2012年第1期24卷 124-130页

作者： yujie zhang Yujing Mu Junfeng Liu Abdelwahid Mellouki Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Centre National de Recherche Scientifique-Institut de Combustion AerothermiqueReactivite et Environnement(CNRS-ICARE)45071 Orleans cedex 02France

The atmospheric concentrations of carbonyls and BTEX （benzene,toluene,ethylbenzene,m,p-xylene and o-xylene） were measured simultaneously at a same sampling site in Beijing from September 2008 to August *** average concentrations of the total measured carbonyls during autumn,winter,spring,and summer were 37.7,31.3,39.7,50.5 μg/m 3,respectively,and maximal values for their diurnal variations usually happened at *** contrast to carbonyls,the average concentrations of the total measured BTEX during the four seasons were 27.2,31.9,23.2,19.1 μg/m 3,respectively,andminimal values for their diurnal variations always occurred in the early *** average concentration for carbonyls increased about 24% from September 2008–August 2009 to September 2009–August 2010,for BTEX,increased about 15%.Integrated life time cancer risks for three carcinogens （benzene,formaldehyde and acetaldehyde） in Beijing exceeded the value of 1E-06,and the hazard quotient （HQ） of non-cancer risk of exposure to formaldehyde exceeded unity.

关键词： carbonyls BTEX sources exposure and risk assessment Beijing