检索结果-南通市图书馆

Microstructure,wear and friction behavior of CoCrAITaY-xCNTs composite coatings deposited by laser-induction hybrid cladding

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第4期43卷 1815-1827页

作者： Sheng-Feng Zhou Yu Long Yan-liang Yi Cheng Deng lian-Xi Hu Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou510632China Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and TechnologyWuhan430074China MOE Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured MaterialsGuangxi UniversityNanning530004China School of Mechatronics Engineering Guangdong Polytechnic Normal UniversityGuangzhou510635China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China

To improve the wear performance of CoCrAlYTa coating,part of the carbon nanotubes(CNTs)chemically reacted with Ta to form reinforcement phase(TaC),while the other CNTs were retained as lubrication ***,the CoCrAlYTa-xCNTs(x=0,1,2,and 4;wt%)composite coatings were prepared by laserinduction hybrid cladding(LIHC),and the microstructure and wear resistance of coatings were systematically *** show that the coatings are mainly composed of TaC,y-(Co,Cr)andβ-(Co,Cr)*** the CNTs content increases from 0 wt%to 4 wt%,the volume fraction of TaC increases from 13.11 vol%to 16.12 vol%.Meanwhile,the nano-hardness ofγ-(Co,Cr)andβ-(Co,Cr)Al are improved from 7.49 and 9.72 to 9.36 and 11.19 GPa,*** a result,the microhardness of coating increases from HV536.25 to HV 738.16,the wear rate decreases from32.4×10^(-3)to 6.1×10^(-3)mg·m^(-1),and the average friction coefficient decreases from 0.55 to *** good wear performance of the coating is attributed to the formation of TaC and the existence of remained CNTs lubricant film.

关键词： Carbon nanotube MCrAlY coating Friction and wear performance Laser-induction hybrid cladding

Determination of ice jam thickness—A new approach

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第3期36卷 570-581页

作者： Jun Wang lian-sheng Sang Fei-hu Song Tie-jie Cheng Jueyi Sui School of Civil and Water Engineering Hefei University of TechnologyHefei230009China School of Engineering University of Northern British ColumbiaPrince GeorgeCanada

In winter,rivers in cold regions often experience flood disasters resulted from ice jams or ice *** of the variation of ice jam thickness and water level during an ice jammed period are not only a practical need for ice prevention to avoid disaster and plan water resource,but also essential for the development of any mathematical model for predicting the evolution of ice *** far,some equations based on the energy equation have been proposed to describe the relationship between ice jam thickness and water ***,in the derivation of these equations,the local head loss coefficient at the ice jam head and the riverbed slope factor were ***,those reported equations cannot be used to preciously describe the flow energy equation with ice jams and accurately calculate the ice jam thickness and water *** the present study,a more comprehensive theoretical model for hydraulic calculation of ice jam thickness has been derived by considering important and essential factors including riverbed slope and local head loss coefficient at the ice jam ***,based on the data collected from laboratory experiments of ice jam accumulation,the local head loss coefficient at the ice jam head has been calculated,and the empirical equation for calculating the local head loss coefficient has been established by considering flow Froude number and the ratio of ice discharge to flow *** results of this study not only provide a new reference for calculating ice jam thickness and water level,but also present a theoretical basis for accurate CFD simulation of ice jams.

关键词： Energy equation ice jam thickness local head loss coefficient ice jam head riverbed slope

经皮骶髂螺钉与重建钢板治疗Tile C型骨盆后环骨折效果的Meta分析

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中华创伤骨科杂志 2017年第6期19卷 476-483页

作者：张昌猛李皓霎朱智杨锴连鸿凯孙天胜郑州大学附属郑州中心医院骨一科 450007 陆军总医院全军创伤骨科研究所北京100700

目的通过Mata分析评价经皮骶髂螺钉与重建钢板治疗TileC型骨盆后环骨折的临床疗效。方法计算机检索Cochrane图书馆、Medline、Embase、CNKI、万方数据库和中国生物医学文献数据库，手工检索相关文献的参考文献及主要中、英文骨科杂志。... 详细信息

目的通过Mata分析评价经皮骶髂螺钉与重建钢板治疗TileC型骨盆后环骨折的临床疗效。方法计算机检索Cochrane图书馆、Medline、Embase、CNKI、万方数据库和中国生物医学文献数据库，手工检索相关文献的参考文献及主要中、英文骨科杂志。收集自建库至2016年12月所有比较经皮骶髂螺钉与重建钢板治疗Tile C型骨盆后环骨折的随机对照研究（RCT）和临床对照研究（CCT），评价纳入研究的方法学质量并提取资料，采用Cochrane协作网提供的RevMan5．2软件进行系统评价。结果共纳入4篇临床研究，其中1篇为RCT，3篇为CCTs，共计334例患者，其中经皮骶髂螺钉组162例，重建钢板组172例（经皮重建钢板组66例，前路重建钢板组106例）。Meta分析结果显示：经皮骶髂螺钉组的手术时间与经皮重建钢板组比较差异无统计学意义（P=0．16），经皮骶髂螺钉组手术时间少于前路重建钢板组，差异有统计学意义（P〈0．001）；经皮骶髂螺钉组切口长度及术中出血量方面均显著小于经皮重建钢板组和前路重建钢板组，差异有统计学意义（P〈0．001），但经皮骶髂螺钉组的术中x线暴露次数显著多于经皮重建钢板组，差异有统计学意义（P〈0．001）；经皮骶髂螺钉组与经皮重建钢板组问骨折复位Matta标准优良率及功能恢复Majeed标准优良率比较差异均无统计学意义（P〉0．05），经皮骶髂螺钉组优于前路重建钢板组，差异有统计学意义（P〈0．001）；经皮骶髂螺钉组的术后并发症发生率显著低于前路重建钢板组，差异有统计学意义（P〈0．001），经皮骶髂螺钉组与经皮重建钢板组的术后骨折部位疼痛发生率差异无统计学意义（P=0．30）。结论与前路重建钢板固定相比，经皮骶髂螺钉和经皮重建钢板固定具有更好的临床疗效和较低的并发症发生率，其中经皮骶髂螺钉在手术切口和术中出血量方面占优，但需要较多的术中x线透视，且技术要求更高。

关键词：骨盆骨折骨折固定术,内系统评价

Applications of single-cell RNA sequencing in spermatogenesis and molecular evolution

在线全文

学校读者我要写书评

暂无评论

Zoological Research 2024年第3期45卷 575-585页

作者： Wen-Bo Chen Meng-Fei Zhang Fan Yang Jin-lian Hua College of Veterinary Medicine Shaanxi Centre of Stem Cells Engineering&TechnologyNorthwest A&F UniversityYanglingShaanxi 712100China Key Laboratory of Livestock Biology Northwest A&F UniversityYanglingShaanxi 712100China

Spermatogenic cell heterogeneity is determined by the complex process of spermatogenesis ***,effectively revealing the regulatory mechanisms underlying mammalian spermatogenic cell development and differentiation via traditional methods is *** in technology have led to the emergence of many single-cell transcriptome sequencing protocols,which have partially addressed these *** this review,we detail the principles of 10x Genomics technology and summarize the methods for downstream analysis of single-cell transcriptome sequencing ***,we explore the role of single-cell transcriptome sequencing in revealing the heterogeneity of testicular ecological niche cells,delineating the establishment and disruption of testicular immune homeostasis during human spermatogenesis,investigating abnormal spermatogenesis in humans,and,ultimately,elucidating the molecular evolution of mammalian spermatogenesis.

关键词： Single-cell RNA sequencing(scRNA-seq) Spermatogenesis Molecular evolution Sertoli cell

B-COPNA resin formation from ethylene tar light fractions:Process development and mechanical exploration by molecular simulation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第6期70卷 118-129页

作者： Hongyan Shen Lingrui Cui Xingguo Wei Yuanqin Zhang lian Cen Jun Xu Fahai Cao Engineering Research Center of Large Scale Reactor East China University of Science and TechnologyShanghai 200237China

An efficient utilization strategy of ethylene tar(ET),the main by-product of the ethylene cracking unit,is urgently required to meet demands for modern petrochemical *** the other hand,condensed polynuclear aromatic resin of moderate condensation degree(B-COPNA)is a widely used carbon material due to its superb processability,the production of which is,however,seriously limited by the high cost of raw *** such context,an interesting strategy was proposed in this study for producing B-COPNA resin using crosslinked light fractions of ethylene tar(ETLF,boiling point<260℃)facilitated by molecular simulation.1,4-Benzenedimethanol(PXG)was first selected as the crosslinking agent according to the findings of molecular *** effects of operating conditions,including reactions temperature,crosslinking agent,and catalyst content on the softening point and yield of B-COPNA resin products were then investigated to optimize the *** reaction mechanism of resin production was studied by analyzing the molecular structure and transition state of ETLF and crosslinking *** was shown that PXG exhibited a superior capacity of withdrawing electrons and a higher electrophilic reactivity than other crosslinking *** addition to the highest yield and greatest heat properties,PXG-prepared resin contained the most condensed *** corresponding optimized conditions of resin preparation were 180℃,1:1.9(PXG:ETLF),and 3%(mass)of catalyst content with a resin yield of 78.57%.It was the electrophilic substitution reaction that occurred between the ETLF and crosslinking agent molecules that were responsible for the resin formation,according to the experimental characterization and molecular ***,it was confirmed that the proposed strategy and demonstrated process can achieve a clean and high value-added utilization of ETLF via B-COPNA resin preparation,bringing huge economic value to the current petrochemical industry.

关键词： Ethylene tar Crosslinking COPNA resin Molecular simulation Transient state

Mode-insensitive and mode-selective optical switch based on asymmetric Y-junctions and MMI couplers

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2024年第3期12卷 423-430页

作者： SHIJIE SUN QIDONG YU YUANHUA CHE TIANHANG lian YUHANG XIE DAMING ZHANG XIBIN WANG State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China

Driven by the large volume demands of data in transmission systems,the number of spatial modes supported by mode-division multiplexing(MDM)systems is being increased to take full advantage of the parallelism of the signals in different spatial *** a key element for photonic integrated circuits,the multimode waveguide optical switch(MWOS)is playing an important role for data exchange and signal ***,the function of the traditional MWOS is simple,which could only implement the mode-insensitive or mode-selective switching function;it is also difficult to scale to accommodate more spatial modes because of the limitation of the device ***,it is still challenging to realize a multifunctional and scalable MWOS that could support multiple modes with low power consumption and high ***,we propose and experimentally demonstrate a multifunctional MWOS based on asymmetric Y-junctions and multimode interference(MMI)couplers fabricated on a polymer waveguide *** mode-insensitive and mode-selective switching functions can be achieved via selectively heating different electrode *** fabricated device with the total length of∼0.8 cmshows an insertion loss of less than 12.1 dB,and an extinction ratio of larger than 8.4 dB with a power consumption of∼32 mW for both mode-insensitive and mode-selective switching functions,at 1550 nm *** proposed MWOS can also be scaled to accommodate more spatial modes flexibly and easily,which can serve as an important building block for MDM systems.

关键词： waveguide optical mode

Recent progress in bio-inspired macrostructure array materials with special wettability—from surface engineering to functional applications

在线全文

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2024年第1期6卷 208-256页

作者： Zhongxu lian Jianhui Zhou Wanfei Ren Faze Chen Jinkai Xu Yanling Tian Huadong Yu School of Mechanical and Aerospace Engineering Jilin UniversityChangchun 130022People’s Republic of China Ministry of Education Key Laboratory for Cross-Scale Micro and Nano Manufacturing Changchun University of Science and TechnologyChangchun 130022People’s Republic of China College of Mechanical and Electrical Engineering Changchun University of Science and TechnologyChangchun 130022People’s Republic of China School of Mechanical Engineering Tianjin UniversityTianjin 300350People’s Republic of China School of Engineering University of WarwickCoventry CV47ALUnited Kingdom

Bio-inspired macrostructure array(MAA,size:submillimeter to millimeter scale)materials with special wettability(MAAMs-SW)have attracted significant research attention due to their outstanding performance in many applications,including oil repellency,liquid/droplet manipulation,anti-icing,heat transfer,water collection,and oil–water *** this review,we focus on recent developments in the theory,design,fabrication,and application of bio-inspired *** first review the history of the basic theory of special wettability and discuss representative structures and corresponding functions of some biological surfaces,thus setting the stage for the design and fabrication of bio-inspired *** then summarize the fabrication methods of special wetting MAAs in terms of three categories:additive manufacturing,subtractive manufacturing,and formative manufacturing,as well as their diverse functional applications,providing insights into the development of these ***,the challenges and directions of future research on bio-inspired MAAMs-SW are briefy *** efforts,progress,and breakthroughs from surface engineering to functional applications elaborated herein will promote the practical application of bio-inspired MAAMs-SW.

关键词： macrostructure arrays superhydrophobic 3D printing laser droplet manipulation

Physical Layer Encryption of OFDM-PON Based on Quantum Noise Stream Cipher with Polar Code

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第3期21卷 174-188页

作者： Xu Yinbo Gao Mingyi Zhu Huaqing Chen Bowen Xiang lian Shen Gangxiang Jiangsu Engineering Research Center of Novel Optical Fiber Technology and Communication Network Suzhou Key Laboratory of Advanced Optical Communication Network Technologythe School of Electronic and Information EngineeringSoochow UniversityNo.1 Shizi StreetSuzhou 215006China

Orthogonal frequency division multiplexing passive optical network(OFDM-PON) has superior anti-dispersion property to operate in the C-band of fiber for increased optical power budget. However,the downlink broadcast exposes the physical layer vulnerable to the threat of illegal eavesdropping. Quantum noise stream cipher(QNSC) is a classic physical layer encryption method and well compatible with the OFDM-PON. Meanwhile, it is indispensable to exploit forward error correction(FEC) to control errors in data transmission. However, when QNSC and FEC are jointly coded, the redundant information becomes heavier and thus the code rate of the transmitted signal will be largely reduced. In this work, we propose a physical layer encryption scheme based on polar-code-assisted QNSC. In order to improve the code rate and security of the transmitted signal, we exploit chaotic sequences to yield the redundant bits and utilize the redundant information of the polar code to generate the higher-order encrypted signal in the QNSC scheme with the operation of the *** experimentally demonstrate the encrypted 16/64-QAM, 16/256-QAM, 16/1024-QAM, 16/4096-QAM QNSC signals transmitted over 30-km standard single mode fiber. For the transmitted 16/4096-QAM QNSC signal, compared with the conventional QNSC method, the proposed method increases the code rate from 0.1 to 0.32 with enhanced security.

关键词： physical layer encryption polar code quantum noise stream cipher

Performance analysis of the tight combination of GPS, BDS, GALILEO, and QzsS mixed frequencies signals

在线全文

学校读者我要写书评

暂无评论

Geodesy and Geodynamics 2024年第4期15卷 366-378页

作者： Yu Han Fangjun Qin Xugang lian Shengliang Wang Leiyuan Qian Wenhua Huang College of Electrical Engineering Naval University of EngineeringWuhan 430033China College of Mining Engineering Taiyuan University of TechnologyTaiyuan 030024China State Key Laboratory of Satellite Navigation System and Equipment Technology Shijiazhuang 050081China State Key Laboratoryof Geodesy and Earth'sDynamics Innovation AcademyforPrecision Measurement Scienceand Technology Chinese Academy of SciencesWuhan 430077China China Energy Engineering Group Shanxi Electric Power Engineering CO.LTD. Taiyuan 030001China

With the gradual development and modernization of satellite navigation systems,using observation information from multi-GNss has become one of the hot-spot issues in recent ***-system loose combinations form double-difference observation equations within their respective systems,and the positioning effect is ***,the interchangeability and compatible interoperability between global navigation satellite systems(GNSS)cannot be truly *** the same time,when the number of visible satellites decreases abruptly,the positioning performance deteriorates *** paper focuses on the GNsS multi-system tight combination relative positioning technique,gives a mathe-matical model of multi-system tight combination relative positioning considering differential inter-system bias(DISB),and analyzes the time-varying characteristics of DISB at overlapping and non-overlapping frequencies among GPS/Galileo,GPS/BDS,and GPS/QZSS in terms of receiver brand,tem-perature,and receiver *** GNsS tight combination relative positioning performance is verified by static data from Curtin University and dynamic data measured at Taiyuan University of *** results show that compared with loose combination,the ambiguity-fixed rate increases from 62.18%to 97.60%for static data and from 74.97%to 99.53%for dynamic data when the elevation mask angle is 50°,resulting in a significant improvement in positioning performance.

关键词： GNSS Mix frequencies Redundancy Tightcombination Differential inter-system bias