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Secure Channel Free ID-Based Searchable Encryption for Peer-to-Peer Group

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Journal of Computer Science & Technology 2016年第5期31卷 1012-1027页

作者： xiao-Fen Wang Yi Mu Rongmao Chen xiao-song zhang College of Computer Science and Engineering University of Electronic Science and Technology of China Chengdu 611731 China Big Data Research Center University of Electronic Science and Technology of China Chengdu 611731 China School of Computing and Information Technology University of Wollongong Wollongong NSW 2500 Australia College of Computer National University of Defense Technology Changsha 410073 China

Data sharing and searching are important functionalities in cloud storage. In this paper, we show how to securely and flexibly search and share cloud data among a group of users without a group manager. We formalize a novel cryptosystem： secure channel free searchable encryption in a peer-to-peer group, which features with the secure cloud data sharing and searching for group members in an identity-based setting. Our scheme allows group members to join or leave the group dynamically. We present two schemes： basic scheme and enhanced scheme. We formally prove that our basic scheme achieves consistency and indistinguishability against the chosen keyword and ciphertext attack and the outsider＇s keyword guessing attack, respectively. An enhanced scheme is also proposed to achieve forward secrecy, which allows to revoke user search right over the former shared data.

关键词： searchable encryption forward secrecy data sharing peer-to-peer group

Research progress on the hydrodynamic performance of water-air-bubble mixed flows around a ship

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Journal of Hydrodynamics 2022年第2期34卷 171-188页

作者： Zheng Li xiao-song zhang De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The interaction between ship and surrounding fluids generates the water-air-bubble mixed flow laden with numerous droplets and *** water-air-bubble mixed flow is a complex multi-phase flow phenomenon,which involves intense air-water mixture,complex evolution of interface shape,interactions between multi-scale flow structures and strong turbulent *** on the field observations at sea,a large range of white water-air-bubble flow exists widely around a large-scale sailing ship,and directly affects the hydrodynamic performance of ship from various *** paper reviews the research progress of water-air-bubble mixed flow around a *** knowledge about the formation and evolution mechanism are introduced ***,the effects of the water-air-bubble mixed flow on ship performance are further reviewed,the main concerns are ship resistance,propulsion performance,slamming and ***,the future research prospects are summarized.

关键词： Water-air-bubble mixed flow ship resistance propulsion performance ship slamming characteristics maneuverability

Numerical techniques for coupling hydrodynamic problems in ship and ocean engineering

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Journal of Hydrodynamics 2020年第2期32卷 212-233页

作者： xiao-song zhang Jian-hua Wang De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) State Key Laboratory of Ocean EngineeringSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China

Most hydrodynamic problems in ship and ocean engineering are complex and highly *** the trend of intelligent and digital design for ships and ocean engineering structures,comprehensive performance evaluation and optimization are of vital importance during *** this process,various coupling effects need to be accurately *** the significant progress of computational fluid dynamics(CFD),many advanced numerical models were proposed to simulate the complex coupling hydrodynamic problems in ship and ocean engineering *** this paper,five key coupling hydrodynamic problems are introduced,which are hull-propeller-rudder coupling,wave-floating structure coupling,aerodynamic-hydrodynamic coupling,fluid structure coupling and fluid-noise coupling,*** paper focuses on the numerical simulation techniques corresponding to each coupling problem,including the theories and the *** directions and conclusions are provided finally.

关键词： Coupling hydrodynamic problems numerical techniques ship and ocean engineering

Experimental and numerical investigation of the impacts of rotor tip-rake on excitation forces of pump-jet propulsors

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Journal of Hydrodynamics 2024年第1期36卷 142-157页

作者： Xue-qin Ji xiao-song zhang Chen-jun Yang xiao-qian Dong State Key Laboratory of Ocean Engineering Marine Numerical Experiment CentreSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China CSSC Shanghai Marine Energy Saving Technology Co. Ltd.Shanghai200011China China Ship Scientific Research Center Shanghai Branch Shanghai200011China

The tip-clearance flow in a pump-jet propulsor exerts great impacts on the fluctuating pressures and resultant unsteady forces,which are important sources of structural vibrations and radiated noise *** blade geometry close to the tip is an important factor determining the vortex strength in the tip-clearance *** the open-water condition,the effects of raking the rotor tips on the duct-surface fluctuating pressures and the resultant unsteady forces acting on different components of the propulsor are investigated via physical model experiments and the numerical solution of Reynolds-averaged Navier-Stokes(RANS)equations coupled with the SST k-ωturbulence *** measured and simulated results of hydrodynamic pressures are consistent to each other,and the simulated flows help better understand why the fluctuating pressures change with the tip *** strong fluctuations of duct-surface pressures are caused by intensive tip separation *** duct-surface pressure fluctuations are effectively reduced by using the rake distribution near the tip towards blade back side and,for the combination of the five-bladed rotor and the seven-bladed stator,the resultant unsteady horizontal(and vertical)forces acting on the duct and stator are also reduced;while increasing rake leads to negative effect on pressure fluctuations and unsteady horizontal(and vertical)forces acting on all the components of the propulsor.

关键词： Pump-jet tip-clearance tip-rake fluctuating pressures excitation forces

Proactive worm propagation modeling and analysis in unstructured peer-to-peer networks

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第2期11卷 119-129页

作者： xiao-song zhang Ting CHEN Jiong ZHENG Hua LI School of Computer Science & Engineering University of Electronic Science and Technology of China Chengdu 611731 China Unit 78155 of People's Liberation Army Chengdu 610016 China

It is universally acknowledged by network security experts that proactive peer-to-peer (P2P) worms may soon en-gender serious threats to the Internet infrastructures. These latent threats stimulate activities of modeling and analysis of the proactive P2P worm propagation. Based on the classical two-factor model,in this paper,we propose a novel proactive worm propagation model in unstructured P2P networks (called the four-factor model) by considering four factors:(1) network topology,(2) countermeasures taken by Internet service providers (ISPs) and users,(3) configuration diversity of nodes in the P2P network,and (4) attack and defense strategies. Simulations and experiments show that proactive P2P worms can be slowed down by two ways:improvement of the configuration diversity of the P2P network and using powerful rules to reinforce the most connected nodes from being compromised. The four-factor model provides a better description and prediction of the proactive P2P worm propagation.

关键词： Proactive peer-to-peer (P2P) worm propagation modeling Network topology Configuration diversity Attack and defense strategies Four-factor model

Numerical study on the wave pattern characteristic of air layer in cavity and the effects of multiple influence factors

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Journal of Hydrodynamics 2023年第5期35卷 923-941页

作者： xiao-song zhang Xue-qin Ji Lei-qiang Chen Li-jin Gao Hong-bo Huang Fang-wen Hong CSSC Shanghai Marine Energy Saving Technology Co.Ltd. Shanghai200011China China Ship Scientific Research Center Shanghai Branch Shanghai200011China China Ship Scientific Research Center Wuxi214082China School of Naval Architecture Ocean and Civil EngineeringState Key Laboratory of Ocean EngineeringShanghai Jiao Tong UniversityShanghai200240China

Air-layer drag reduction (ALDR) technology for ship energy saving is getting more and more attention in recent years because of the outstanding drag reduction effect. In order to promote practical application, it is necessary to fully understand the two phase flow characteristics of the air layer. Recent experimental studies have shown that the surface of the air layer presents wave pattern, which has an important influence on its damage risk. However, it is difficult to measure the wave pattern quantificationally due to the interference of equipment. The main goal of the present paper is to investigate the wave pattern characteristic of air layer in cavity using numerical simulation method. On this basis, the effect of flow and geometric influence factors are discussed to understand the key control conditions. A computational fluid dynamics (CFD) numerical method based on Reynolds averaged Navier-Stokes (RANS) equations and volume of fluid (VOF) interface capturing method is established, and has been successfully applied in the simulation of air layer wave pattern. Both 2-D and 3-D simulations are carried out, aiming at analyzing air-water interface flow and vortex flow directly. Based on the simulation results, several important conclusions about the mechanism of air layer wave pattern can be obtained. Firstly, it is found to be an inherent characteristic that the wave height of the upstream air layer is higher than that of the downstream. The extremely high wave peak is easy to contact with the flat plate, leading to the breakup of air layer and a “central blank area” phenomenon. With the help of flow analysis, it is found that this characteristic is mainly caused by the strong counterclockwise vortex behind the bow wedge block. Secondly, the air layer stability is reduced with the increase of water flow velocity by affecting the wave height. There is a saturation point of air flow rate to reach maximum thickness of air layer. Thirdly, cavity configuration has ob

关键词： Air layer drag reduction wave pattern of air-water interface numerical simulation multiple influence factors vortex flow fields

Correlation of electromagnetic radiation emitted from coal or rock to supporting resistance

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Mining Science and Technology 2009年第3期19卷 317-320页

作者： JIA Hui-lin WANG En-yuan song xiao-yan zhang Hong-jie LI Zhong-hui School of Safety Engineering China University of Mining ＆ Technology Xuzhou Jiangsu 221008 China

More accurate forecasting of rock burst might be possible from observations of electromagnetic radiation emitted in the *** analyzed experimental observations and field data from the Muchengjian coal mine to study the relationship between electromagnetic radiation signal intensity and stress during the fracturing of coal, or rock, and samples under *** results show that the signal intensity is positively correlated with *** addition, we investigated the change in the electromagnetic radiation intensity, the supporting resistance in a real coal mine environment, and the coal or rock stress in the mining *** data analysis indicates that:1) electromagnetic radiation intensity can accurately reflect the distribution of stress in the mining area;and, 2) there is a correlation between electromagnetic radiation intensity and supporting *** research has some practical guiding significance for rock burst forecasting and for the prevention of accidents in coal mines.

关键词： electromagnetic radiation rock burst supporting resistance coal or rock

Synergistically enhanced ORR and HER performance on Co-N-C coupled in-situ generated PtCo intermetallic

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Journal of Energy Chemistry 2025年第1期100卷 721-729页

作者： Guanyu Luo Min song Lulu An xiao Huang Qian zhang Chenhao zhang Tao Shen Shuang Wang Deli Wang Key Laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology) Ministry of Education School of Chemistry and Chemical Engineering Huazhong University of Science and Technology

Integrating multi-scale sites in a composite catalyst is vital to realize efficient ***,a synergistic composite catalyst consisting of Co atomic sites and in-situ generated PtCo intermetallic compounds （IMCs）(o-PtCo@CoNC) is proposed through Co pre-anchoring and subsequent impregnation-reduction *** loading of Co atoms provides a chance for in-situ generating PtCo ordered intermetallic *** remaining Co single atoms and PtCo IMCs construct synergistic electrocatalytic *** from the ordered structure,synergistic effect of Pt Co IMCs and Co single atoms,o-PtCo@CoNC exhibits excellent electrocatalytic performance for oxygen reduction reaction （ORR） and hydrogen evolution reaction （HER） with mass activity of 1.21 A mgPt-1（at 0.9 V） and5.70 A mgPt-1（at an overpotential of 100 mV）,***,o-PtCo@CoNC delivers negligible loss of half-wave potential and overpotential during long-term stability test in acid solutions,with 13 mV decay after 50,000 potential cycles for ORR and a 2.7 mV decay after 20,000 potential cycles for *** integration strategy of single-atomic sites coupled IMCs paves the way for enhancing the activity and durability of Pt-based electrocatalysts.

关键词： Synergistic effect Intermetallics Single atomic sites Oxygen reduction reaction Hydrogen evolution reaction

Effects of gonadotropin-releasing hormone antagonists on the expression of vascular endothelial growth factor and its receptors in a rat model of ovarian hyperstimulation syndrome

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Chinese Medical Journal 2008年第23期121卷 2434-2439页

作者： TONG xiao-mei zhang song-ying song Tao XU Wei-hai LIN xiao-na SHU Jing LIU Liu Department of Reproductive Medicine Sir Run Run Shaw Hospital Affiliated with School of Medicine Zhejiang University Hangzhou Zhejiang 310016 China

Background Ovarian hyperstimulation syndrome （OHSS） is one of the most life-threatening complications of assisted reproduction treatments. Gonadotropin-releasing hormone antagonists （GnRHanta） are thought to be effective in preventing this complication, and some clinical trials have found lower incidences of OHSS in patients treated with GnRHanta. Our aim was to investigate the effects of GnRHanta on vascular permeability and the expression of vascular endothelial growth factor （VEGF） and its receptors in a rat model of OHSS. Methods An immature early OHSS rat model was established. Three ovarian stimulation protocols were used： pregnant mare serum gonadotropin/human chorionic gonadotropin （hCG） alone, with a GnRHanta, or with a gonadotropin-releasing hormone agonists （GnRHa）. Blood and tissue samples were collected at 48 hours after hCG administration. Vascular permeability was evaluated by measuring the Evans-Blue content of extravasated peritoneal fluids. The expression of VEGF and its receptors, including fit-1 and KDR, were detected by reverse transcriptase-polymerase chain reaction and Western blotting. Results Treatment with both a GnRHanta and a GnRHa resulted in significant reductions in serum estradiol and peritoneal vascular permeability, as well as decreased ovarian expression of VEGF and its two receptors. However, GnRHanta treatment caused a greater reduction in serum estradiol concentrations, and in VEGF receptor mRNA expression than GnRHa. There were no significant reductions in the expression of VEGF or its receptors in extra-ovarian tissues, including the liver, lungs and peritoneum. Conclusion Our results reveal that GnRHanta are more potent than GnRHa in preventing early OHSS through down-regulation of the expression of VEGF and its receptors in hyperstimulated ovaries.

关键词： gonadotropin-releasing hormone antagonist gonadotropin-releasing hormone agonist ovarian hyperstimulation syndrome vascular endothelial growth factor