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Effect of yttrium addition on microstructure, mechanical and corrosion properties of 20Cr13 martensitic stainless steel

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Journal of Iron and Steel Research International 2020年第4期27卷 451-460页

作者： Qi-yu zang Yang-fan Jin Tuo Zhang Yi-tao Yang School of Materials Science and Engineering Shanghai UniversityShanghai 200444China

The effects of rare-earth yttrium(Y)element on the microstructure,mechanical properties and corrosion properties of 20Cr13 martensitic stainless steel were investigated by optical microscopy,scanning electron microscopy and tensile *** experiments were carried out to study the effect of rare-earth element Y addition on corrosion *** results showed that the addition of 0.02 wt.%rare-earth yttrium to martensitic stainless steel could affect the microstructure transformation,and Ac3 temperature was obviously *** the stainless steel after heat treatment,there were more pro-eutectoid ferrite in the steel with 0.02 wt.%*** mechanical test results showed that the addition of 0.02 wt.%yttrium could significantly improve the tensile strength and elongation of the steel,which was related to the influence of yttrium element on inclusions in the test *** the quenching temperature of 0.02 wt.%yttrium steel increasing,the content of the ferrite in steel was affected and the corrosion resistance was remarkably improved.

关键词： Yttrium Martensitic stainless steel Mechanical property Microstructural characterization Corrosion

SplitPass： A Mutually Distrusting Two-Party Password Manager

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Journal of Computer Science & Technology 2018年第1期33卷 98-115页

作者： yu-Tao Liu Dong Du yu-Bin Xia Hai-Bo Chen Bin-yu zang Zhenkai Liang Institute of Parallel and Distributed Systems Shanghai Jiao Tong University Shanghai 200240 China School of Computing National University of Singapore Singapore 117417 Singapore

Using a password manager is known to be more convenient and secure than not using one, on the assmnption that the password manager itself is safe. However recent studies show that most popular password managers have security vulnerabilities that may be fooled to leak passwords without users＇ awareness. In this paper, we propose a new password manager, SplitPass, which vertically separates both the storage and access of passwords into two mutually distrusting parties. During login, all the parties will collaborate to send their password shares to the web server, but none of these parties will ever have the complete password, which significantly raises the bar of a successful attack to compromise all of tile parties. To retain transparency to existing applications and web servers, SplitPass seamlessly splits the secure sockets layer （SSL） and transport layer security （TCP） sessions to process on all parties, and makes the joining of two password shares transparent to the web servers. We have implemented SplitPass using an Android phone and a cloud assistant and evaluated it using 100 apps from top free apps in the Android official market. The evaluation shows that SplitPass securely protects users＇ passwords, while incurring little performance overhead and power consumption.

关键词： password manager privacy protection mobile-cloud system

Behavior of Nb influence on structure and properties of 30Cr13 cast martensitic stainless steel

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Journal of Iron and Steel Research International 2019年第5期26卷 462-471页

作者： Yang-fan Jin Tuo Zhang Qi-yu zang Yi-tao Yang School of Materials Science and Engineering Shanghai University Shanghai 200444 China

The microstructure, mechanical properties and corrosion resistance of 30Cr13 martensitic stainless steel (MSS) with different Nb contents were investigated by using the optical microscope, scanning electron microscope, X-ray diffractometer, HRC hardness measurement apparatus and tensile testing machine. Nb was found to retard the formation of austenite and promote the precipitation of carbides by calculating. The results showed that the addition of 0.2 wt.% Nb elements could improve the strength and corrosion resistance of 30Cr13 martensitic stainless steels while the reduction in toughness was less because of the inhibited effect on Cr-rich carbides precipitation by Nb addition. Specially, M23C6-type carbides almost disappeared in 0.6Nb-MSS. Moreover, the main existent form of Nb element was NbC and the strong carbide-forming ability of Nb element increased the quantity of carbides with the morphology changing from sphericaltype to chain-type. 0.2Nb-MSS shows excellent strength, adequate toughness and sufficient corrosion resistance for the application.

关键词： Niobium addition Martensitic stainless steel Microstructure Mechanical property Corrosion resistance

Frequency-dependent alterations in regional homogeneity in young carriers of the apolipoprotein E genotype

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Science Bulletin 2017年第9期62卷 654-655页

作者： Xi-Ze Jia Yi-Wen Zhang yu-Feng zang Hui-Jie Li CAS Key Laboratory of Behavioral Science Institute of Psychology Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments Center for Cognition and Brain Disorders Hangzhou Normal University Hangzhou 311121 China Institutes of Psychological Sciences Hangzhou Normal University Hangzhou 311121 China

Using resting-state functional magnetic resonance imaging(rf MRI),previous studies showed that the APOE e4 allele might affect the functional connectivity between remote brain regions[1,2].However,the local functional... 详细信息

关键词： test MRI data SPM Re Frequency-dependent alterations in regional homogeneity in young carriers of the apolipoprotein E genotype MTL FWHM FOV

Revisiting Persistent Indexing Structures on Intel Optane DCPersistent Memory

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Journal of Computer Science & Technology 2021年第1期36卷 140-157页

作者： Heng Bu Ming-Kai Dong Ji-Fei Yi Bin-yu zang Hai-Bo Chen Institute of Parallel and Distributed Systems Shanghai Jiao Tong UniversityShanghai 200240China

Persistent indexing structures are proposed in response to emerging non-volatile memory(NVM)to provide high performance yet durable ***,due to the lack of real NVM hardware,many prior persistent indexing structures were evaluated via emulation,which varies a lot across different setups and differs from the real ***,Intel has released its Optane DC Persistent Memory Module(PMM),which is the first production-ready *** this paper,we revisit popular persistent indexing structures on PMM and conduct comprehensive evaluations to study the performance differences among persistent indexing structures,including persistent hash tables and persistent *** to the evaluation results,we find that Cacheline-Conscious Extendible Hashing(CCEH)achieves the best performance among all evaluated persistent hash tables,and Failure-Atomic ShifT B+-Tree(FAST)and Write Optimal Radix Tree(WORT)perform better than other ***,we find that the insertion performance of hash tables is heavily influenced by data locality,while the insertion latency of trees is dominated by the flush *** also uncover that no existing emulation methods accurately simulate PMM for all the studied data ***,we provide three suggestions on how to fully utilize PMM for better performance,including using clflushopt/clwb with sfence instead of clflush,flushing continuous data in a batch,and avoiding data access immediately after it is flushed to PMM.

关键词： persistent memory data structure performance Intel Optane DC persistent memory module(PMM)

Review of tensairity and its applications in agricultural aviation

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International Journal of Agricultural and Biological Engineering 2016年第3期9卷 1-14页

作者： zang Ying Gu Xiuyan Zhou Zhiyan Luo Xiwen zang yu Qi Xingyuan Liu Wulan Yang Cheng College of Engineering South China Agricultural University/Engineering Research Center for Agricultural Aviation Application(ERCAAA)Guangzhou 510642China Collaborative Innovation Center for Grain and Oil Crops in South China Changsha 410128China

In recent years,the unmanned aerial vehicle(UAV)has undergone rapid development in field of agricultural plant protection;however,the payload and max-endurance are bottlenecks that limit its further *** is a new structure consisting of a bag filled with low-pressure gas,an upper rigid rod and a lower flexible *** puts tension pressure on the whole structure through internal gas pressure,provides continuous support to the upper rigid rod,and that is to say,the tensairity improves the stability of the structure in some *** also,tensairity is a self-supporting and self-balancing system,which means it is a simple,lightweight structure with small storage volume,strong bearing capacity,and low engineering *** also has the advantages of gasbag and BSS(beam string structure).The main objective of this research was to introduce the theoretical basis of tensairity and then discussed its development and ***,the advantages and disadvantages of tensairity were summarized,and development prospects of tensairity in agricultural aviation were *** last,it can be concluded that tensairity has potentials in agricultural *** tensairity is applied in agricultural UAVs,it will solve the two major problems of payload and max-endurance better,and help promoting the development of agricultural aviation technology in agricultural aviation administration and ***,it will help with meeting the aerial application requirements of high efficiency and maximal environmental *** research will provide a reference for improving working efficiency and economic benefits of UAVs in agricultural plant protection.

关键词： tensairity agricultural aviation unmanned aerial vehicle(UAV) bionics numerical simulation payload

Design and anti-sway performance testing of pesticide tanks in spraying UAVs

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International Journal of Agricultural and Biological Engineering 2019年第1期12卷 10-16页

作者： yu zang Ying zang Zhiyan Zhou Xiuyan Gu Rui Jiang Lingxi Kong Xingang He Xiwen Luo yubin Lan College of Engineering South China Agricultural University/Guangdong Engineering Research Center for Agricultural Aviation Application(ERCAAA)Guangzhou 510642China National Joint Research Center for Precision Agricultural Aviation Application Technology Guangzhou 510642China Key Laboratory of Key Technology on Agricultural Machine and Equipment(South China Agricultural University) Ministry of EducationGuangzhou 510642China

Anti-sway performance is one of the most important factors that affect the stability of unmanned aerial vehicles(UAVs).In this study,an anti-sway performance testing method and an evaluation formula for pesticide tanks were developed,which could facilitate the design and application of pesticide *** detection device mainly comprises a testing stand,a mounting and testing part,and a driving and control *** the testing method,P(maximum pressure)measured by a barometer and t(fluctuation recovery time)measured by a high-speed camera were used as evaluation *** the aim to determine the optimal position of the pressure detection device and the optimal filling ratio,four representative pesticide tanks were involved in this *** results showed that the optimal position of the pressure detection device was at the middle position on the tank wall,halfway up from the bottom,and the optimal filling ratio was *** P and t as evaluation indexes,a comprehensive evaluation formula was developed based on these tests:S=0.7Pi+***-sway performance of pesticide tanks was evaluated by a comprehensive score.A disk pesticide tank with a baffle was determined to be the best among the four types of pesticide tanks,showing a score of *** scores of the other three pesticide tanks were 0.500,0.428 and 0.612,*** results indicated that the baffle structure in the pesticide tank and the radian design of the tank wall can effectively improve the anti-sway performance of a pesticide *** proposed detection device and test method are simpler and more intuitive compared to other approaches in evaluating the anti-sway performance of pesticide tanks in spraying UAVs,and they can be used as a reference to guide the design of pesticide tanks and the stability evaluation of spraying UAVs.

关键词： spraying UAV pesticide tank liquid sloshing anti-sway performance test detection method

Axial acoustic radiation force on an elastic spherical shell near an impedance boundary for zero-order quasi-Bessel-Gauss beam

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Chinese Physics B 2021年第4期30卷 305-318页

作者： yu-Chen zang Wei-Jun Lin Chang Su Peng-Fei Wu Institute of Acoustics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Shell structures have increasingly widespread applications in biomedical ultrasound fields such as contrast agents and drug delivery,which requires the precise prediction of the acoustic radiation force under various circumstances to improve the system *** acoustic radiation force exerted by a zero-order quasi-Bessel-Gauss beam on an elastic spherical shell near an impedance boundary is theoretically and numerically studied in this *** means of the finite series method and the image theory,a zero-order quasi-Bessel-Gauss beam is expanded in terms of spherical harmonic functions,and the exact solution of the acoustic radiation force is derived based on the acoustic scattering *** acoustic radiation force function,which represents the radiation force per unit energy density and per unit cross-sectional surface,is especially *** simulated results for a polymethyl methacrylate shell and an aluminum shell are provided to illustrate the behavior of acoustic radiation force in this *** simulated results show the oscillatory property and the negative radiation force caused by the impedance *** appropriate relative thickness of the shell can generate sharp peaks for a polymethyl methacrylate *** radiation force can be obtained at small half-cone angles and the beam waist only affects the results at high *** that the quasi-Bessel-Gauss beam possesses both the energy focusing property and the non-diffracting advantage,this study is expected to be useful in the development of acoustic tweezers,contrast agent micro-shells,and drug delivery applications.

关键词： acoustic radiation force zero-order quasi-Bessel-Gauss beam impedance boundary elastic spherical shell

Scaling out NUMA-Aware Applications with RDMA-Based Distributed Shared Memory

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Journal of Computer Science & Technology 2019年第1期34卷 94-112页

作者： Yang Hong Yang Zheng Fan Yang Bin-yu zang Hai-Bing Guan Hai-Bo Chen Shanghai Key Laboratory for Scalable Computing Systems Shanghai Jiao Tong UniversityShanghai 200240China

The multicore evolution has stimulated renewed interests in scaling up applications on shared-memory multiprocessors,significantly improving the scalability of many *** the scalability is limited within a single node;therefore programmers still have to redesign applications to scale out over multiple *** paper revisits the design and implementation of distributed shared memory (DSM)as a way to scale out applications optimized for non-uniform memory access (NUMA)architecture over a well-connected *** paper presents MAGI,an efficient DSM system that provides a transparent shared address space with scalable performance on a cluster with fast network *** is unique in that it presents a NUMA abstraction to fully harness the multicore resources in each node through hierarchical synchronization and memory *** also exploits the memory access patterns of big-data applications and leverages a set of optimizations for remote direct memory access (RDMA)to reduce the number of page faults and the cost of the coherence *** has been implemented as a user-space library with pthread-compatible interfaces and can run existing multithreaded applications with minimized *** deployed MAGI over an 8-node RDMA-enabled *** evaluation shows that MAGI achieves up to 9.25:4 speedup compared with an unoptimized implementation,leading to a sealable performance for large-scale data-intensive applications.

关键词： distributed shared memory (DSM) scalability multieore evolution non-uniform memory access (NUMA) remote direct memory access (RDMA)