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烧结温度对车用石墨-TiB_(2)增强铜基复合材料组织与性能的影响

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材料热处理学报 2024年第5期45卷 32-39页

作者：高希瑞李恒青韦江郑宝超刘洋赈上海交通职业技术学院汽车工程学院上海201900 暨南大学先进耐磨蚀及功能材料研究院广东广州510632 江西省科学院应用物理研究所江西南昌330096

采用真空热压烧结方法制备了石墨和TiB_(2)混杂增强Cu基复合材料,研究了烧结温度对复合材料微观结构、致密度、显微硬度、电导率和摩擦磨损性能的影响。结果表明:烧结过程中各粉末原料没有发生氧化,同时粉末之间也没有发生化学反应。两... 详细信息

采用真空热压烧结方法制备了石墨和TiB_(2)混杂增强Cu基复合材料,研究了烧结温度对复合材料微观结构、致密度、显微硬度、电导率和摩擦磨损性能的影响。结果表明:烧结过程中各粉末原料没有发生氧化,同时粉末之间也没有发生化学反应。两种增强相均匀地分散在连续的Cu基体中,同时颗粒之间没有形成聚集。随着烧结温度的升高,复合材料的致密度和显微硬度先增大后减小,摩擦系数和磨损率先减小后增大,电导率逐渐降低。烧结温度为800℃时,石墨和TiB_(2)混杂增强Cu基复合材料具有较优异的综合性能,其致密度、显微硬度、电导率、摩擦系数和磨损率分别为98.8%、92.2 HV0.1、43.2%IACS、0.213和1.757×10^(-5)mm^(3)/(N·m),磨损机制为显微切削为主,粘着磨损为辅。

关键词： Cu基复合材料烧结温度力学性能摩擦系数磨损率

Rating-protocol optimization for blockchain-enabled hybrid energy trading in smart grids

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Science China(Information Sciences) 2023年第5期66卷 297-298页

作者： zheng bao Changbing TANG Feilong LIN Zhonglong zheng Xinghuo YU College of Mathematics and Computer Science Zhejiang Normal University College of Physics and Electronics Information Engineering Zhejiang Normal University School of Engineering RMIT University

Dear editor,Smart grids, with renewable energy technologies, provide an innovative approach for mitigating the energy crisis caused by the shortage of fossil fuel resources. However, the existing smart grids are confronted with several challenges [1, 2].Specially, the decentralization of resources and the inflexible trading patterns call for a secure infrastructure and an efficient energy management mechanism, respectively.

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Ground moving target detection and location based on SAR images for distributed spaceborne SAR

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Science in China(Series F) 2005年第5期48卷 632-646页

作者： LI Zhenfang bao zheng YANG Fengfeng Key Laboratory for Radar Signal Processing Xidian University Xran 710071 China National University of Defence Technology Changsha 4100731 China

This paper investigates data processing approaches to detect and locate ground moving targets using distributed spaceborne SAR systems with long cross-track baselines. In particular, it investigates the performance of ground moving target detection for two typical satellite formations： Cartwheel and Pendulum. An approach based on SAR images and a space-time adaptive processing （STAP） algorithm is proposed in order to overcome the effects of the ground terrain on the clutter suppression. The key idea of the approach is firstly to reduce the clutter degrees of freedom greatly by using conventional SAR imaging processing. Then the ground terrain clutter within each SAR pixel can be effectively cancelled by using the very limited spatial degrees of freedom. Finally, constant-false-alarm-rate （CFAR） techniques can be used to detect the remaining target SAR pixels after clutter cancellation. An approach to relocate the detected targets is also proposed, which is based on the estimation of the Doppler spectrum shifts of ground moving targets relative to the clutter Doppler spectrum. The proposed approaches in this paper have the advantages of simplicity and high efficiency.

关键词： formation-flying satellites ground moving target indication spaceborne synthetic apertureradar (spaceborne SAR) space-time adaptive processing (STAP) cartwheel pendulum.

ERCP联合LC对胆囊结石合并胆总管结石患者手术指标与并发症的影响

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黔南民族医专学报 2024年第1期37卷 39-41页

作者：陈超曾保征余曦麻城市人民医院湖北麻城438300

目的:明确ERCP(内镜逆行胰胆管造影)联合LC(腹腔镜胆囊切除术)在胆囊结石合并胆总管结石治疗中的应用价值。方法:研究采用数字随机方式将80例胆囊结石合并胆总管结石患者进行分组;参照组患者治疗采用传统开腹方式,试验组采用ERCP联合LC... 详细信息

目的:明确ERCP(内镜逆行胰胆管造影)联合LC(腹腔镜胆囊切除术)在胆囊结石合并胆总管结石治疗中的应用价值。方法:研究采用数字随机方式将80例胆囊结石合并胆总管结石患者进行分组;参照组患者治疗采用传统开腹方式,试验组采用ERCP联合LC方式;对两组患者的手术情况(术中出血量、手术持续时间、住院治疗时间)、取石成功率与结石残余率、术后恢复效果(下床活动时间、拔除引流管时间、首次肛门排气时间)及术后并发症进行比较。结果:与参照组比较,试验组患者手术持续时间长、术中出血量少、住院持续时间短(P0.05);与参照组比较,试验组患者独自下床活动时间、拔除引流管时间及首次肛门排气时间均短于参照组(P<0.05);试验组术后并发症发生率显著低于参考组(P<0.05)。结论:针对胆囊结石合并胆总管结石患者的手术治疗,采用ERCP联合LC的效果显著。

关键词： ERCP LC 胆囊结石胆总管结石手术指标并发症

Weighted cooperative routing for wireless mobile Ad-hoc network

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The Journal of China Universities of Posts and Telecommunications 2007年第1期14卷 16-21页

作者： ZHAO Xian-jing zheng bao-yu CHEN Chao Institute of Signal and Information Processing Nanjing University of Posts and Telecommunications Nanjing 210003 China

A novel weighted cooperative routing algorithm （WCRA） is proposed in this article, which was on the basis of a weighted metric with maximal remaining energy （MRE） of the relays and the maximal received SNR （MRS） of the nodes. Moreover, a cooperative routing protocol was implemented on the basis of WCRA. Then simulation is done on network simulation （NS-2） platform to compare the performances of MRS, MRE and WCRA with that of noncooperative destination-sequenced destination-sequenced distance-vector （DSDV） protocol. The simulative results show that WCRA obtains a performance tradeoff between MRE and MRS in terms of delivery ratio and network lifetime, which can effectively improve the network lifetime at an acceptable loss of delivery ratio.

关键词： weighted cooperative routing Ad-hoc networks,quality of service DSDV routing protocol

The research of cooperative routing algorithm in mobile Ad hoc networks

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The Journal of China Universities of Posts and Telecommunications 2006年第3期13卷 5-10页

作者： CHEN Chao zheng bao-yu ZHAO Xian-jing Institute of Signal and Information Processing Nanjing University of Posts and Telecommunications Nanjing 210003 China

Cooperative routing technology can efficiently improve the performance of the network by initiatively selecting cooperative nodes to forward the data. In this article, cooperative routing algorithms are proposed and implemented based on three different criteria： optimal channel state, maximal remaining energy, and the shortest path. The simulation based on network simulation （NS） compares the performance of the proposed algorithms with non-cooperative destination-sequenced distancevector （DSDV） protocol. The results reveal that cooperative algorithms outperform DSDV routing protocol with distinctive gains at the cost of sacrificing acceptable normalized network load.

关键词： cooperative routing crosslayer DSDV routing protocol Ad hoc networks

Azimuth resolution improvement for spaceborne SAR images with quasi-non-overlapped Doppler bandwidth

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Journal of Systems Engineering and Electronics 2014年第3期25卷 422-427页

作者： Yanyang Liu Zhenfang Li Zhiyong Suo Jinwei Li zheng bao National Laboratory of Radar Signal Processing Xidian University

The azimuth resolution improvement problem is solved via a coherent combination of synthetic aperture radar （SAR） ima-ges with the quasi-non-overlapped Doppler bandwidth. Prior to the spectra combination, SAR images should be coregistered, while phase biases induced by topography, atmospheric propagation delays and baseline measurement errors should be calibrated. However, the coregistration accuracy suffers from large Doppler decorrelation caused by the quasi-non-overlapped Doppler band-width. Furthermore, the method used to estimate phase biases from interferogram of azimuth prefiltered SAR image pairs wil fail when there is no overlapped spectrum. The fringe simulation and maximum sharpness optimization are adopted to deal with the problems. Accordingly, a novel algorithm to coherently synthesize SAR images is presented. The experiment with the Terra SAR X-band （TerraSAR-X） satel ite data validates the performance of the presented method.

关键词： synthetic aperture radar (SAR) azimuth resolution improvement maximum sharpness optimization fringe simulation.

不同服役期TP347HFG钢管显微组织与力学性能的对比

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金属热处理 2024年第5期49卷 10-16页

作者：鲍峥程翔王若民缪春辉陈国宏汤文明合肥工业大学材料科学与工程学院安徽合肥230009 安徽新力电业科技咨询有限责任公司安徽合肥230601 国网安徽省电力有限公司电力科学研究院安徽合肥230601

针对供货态以及在600℃服役约50000 h、110000 h的TP347HFG钢高温再热器管,开展显微组织与力学性能的对比研究。结果表明,服役50000 h的管样中奥氏体晶粒正常长大,且伴随着细小M_(23)C_(6)颗粒的析出,第二相弥散强化效应增加,相比于供货... 详细信息

针对供货态以及在600℃服役约50000 h、110000 h的TP347HFG钢高温再热器管,开展显微组织与力学性能的对比研究。结果表明,服役50000 h的管样中奥氏体晶粒正常长大,且伴随着细小M_(23)C_(6)颗粒的析出,第二相弥散强化效应增加,相比于供货态TP347HFG钢管,具有更高的屈服强度。但服役110000 h的TP347HFG钢管样显微组织老化严重,部分奥氏体晶粒异常长大,且粗大M_(23)C_(6)颗粒对晶界的割裂作用增大,导致其室温、高温力学性能普遍降低。此外,随着服役时间的延长,TP347HFG钢管样的冲击性能不断降低,断口塑性变形特征不断弱化,组织老化对服役态试样力学性能的影响愈加明显。

关键词： TP347HFG耐热钢管长期服役显微组织力学性能

Synthesis of phenol-class azo derivatives of 4-aminosalicylic acid

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Chinese Chemical Letters 2008年第4期19卷 419-422页

作者： Shi Fei Sheng Hui Xia zheng Jiang Liu zheng bao Zhao School of Pharmaceutical Science Shanxi Medical UniversityTaiyuan 030001China First Clinical College Shanxi Medical UniversityTaiyuan 030001China

To explore the better prodrug of 4-aminosalicylic acid（4-ASA）with higher activity and less side effects against the inflammatory bowel disease.4-ASA,after a succession of synthesis process,was conjugated with various carder molecules to get seven azo derivatives of *** compounds were characterized by FT-IR,^1H NMR,^13C NMR spectras in *** derivatives of 4-ASA were definituded.

关键词： 4-Aminosalicylic acid Azo derivatives of 4-aminosalicylic acid Inflammatory bowel disease