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Fe_(3)N磁性纳米粒子的制备及其应用研究进展

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化学工程师 2024年第1期38卷 61-65,74页

作者：秦伟宁魏立新贾新磊东北石油大学石油工程学院黑龙江大庆163319 滨州学院化工与安全学院山东滨州256600

Fe_(3)N作为一种磁性纳米粒子,同时具有纳米粒子和磁性物质的特殊性质,由于其优异的机械强度、耐腐蚀抗氧化能力等特点,近年来广泛应用于磁流体、电极材料和催化等领域。本文论述了Fe_(3)N磁性纳米材料的结构,在对Fe_(3)N的制备方法进... 详细信息

Fe_(3)N作为一种磁性纳米粒子,同时具有纳米粒子和磁性物质的特殊性质,由于其优异的机械强度、耐腐蚀抗氧化能力等特点,近年来广泛应用于磁流体、电极材料和催化等领域。本文论述了Fe_(3)N磁性纳米材料的结构,在对Fe_(3)N的制备方法进行综述的基础上,详细介绍了物理和化学两种制备方法,并总结了Fe_(3)N磁性纳米材料在各领域中的应用,同时对Fe_(3)N磁性纳米材料未来研究应用进行了展望。

关键词：氮化铁 Fe_(3)N 磁性纳米材料制备方法

Ultrathin 2D Conjugated Polymer Nanosheets for Solar Fuel Generation

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Chinese Journal of Polymer Science 2019年第2期37卷 101-114页

作者： xin-lei Zhang lei Wang Liang Chen Xiao-Yu Ma Hang-Xun Xu Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry Department of Polymer Science and Engineering Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China

Two-dimensional(2 D) polymers are fascinating as they exhibit unique physical, chemical, mechanical, and electronic properties that are completely different from those of traditional linear or branched polymers. They are very promising for applications in catalysis, separation, optoelectronics, energy storage, and nanomedicine. Recently, ultrathin 2 D conjugated polymers have emerged as advanced materials for converting solar energy into chemical energy. The inherent 2 D planar structure with in-plane periodicity offers many features that are highly desirable for photon-involved catalytic energy conversion processes, including high absorption coefficients,large surface areas, abundant surface active sites, and efficient charge separation. Moreover, the possibility of finely tuning the optoelectronic and structural properties through precise molecular engineering has opened up new opportunities for design and synthesis of novel 2 D polymer nanosheets with unprecedented applications. Herein, we highlight recent advances in developing ultrathin 2 D conjugated polymer nanosheets for solar-to-chemical energy conversion. Specifically, we discuss emerging applications of ultrathin 2 D conjugated polymer nanosheets for solar-driven water splitting and CO2 reduction. Meanwhile, future challenges and prospects for design and synthesis of ultrathin 2 D conjugated polymer nanosheets for solar fuel generation are also included.

关键词： 2D polymers Conjugated polymers Nanosheets Photocatalysis Energy conversion

A study on coherent structures and drag-reduction in the wall turbulence with polymer additives by TRPIV

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Acta Mechanica Sinica 2013年第4期29卷 485-493页

作者： xin-lei Guan Shi-Yong Yao Nan Jiang Department of Mechanics Tianjin University Tianjin Key Laboratory of Modern Engineering Mechanics The State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Nankai University-Tianjin University Center for Liu Hui Applied Mathematics

An experimental measurement was performed us- ing time-resolved particle image velocimetry （TRPIV） to in- vestigate the spatial topological character of coherent struc- tures in wall-bounded turbulence of polymer additive solu- tion. The fully developed near-wall turbulent flow fields with and without polymer additives at the same Reynolds number were measured by TRPIV in a water channel. The compar- isons of turbulent statistics confirm that due to viscoelastic structure of long-chain polymers, the wall-normal velocity fluctuation and Reynolds shear stress in the near-wall region are suppressed significantly. Furthermore, it is noted that such a behavior of polymers is closely related to the decease of the motion of the second and forth quadrants, i.e., the ejection and sweep events, in the near-wall region. The spa- tial topological mode of coherent structures during bursts has been extracted by the new mu-level criteria based on locally averaged velocity structure function. Although the general shapes of coherent structures are unchanged by polymer additives, the fluctuating velocity, velocity gradient, velocity strain rate and vorticity of coherent structures during burst events are suppressed in the polymer additive solution com- pared with that in water. The results show that due to the polymer additives the occurrence and intensity of coherent structures are suppressed, leading to drag reduction.

关键词： Time-resolved particle image velocimetry ~ Wall-bounded turbulence ~ Coherent structures ~ Polymer addi-tives ~ Drag reduction

腐蚀-疲劳荷载耦合作用下桥梁拉索高强钢丝自漏磁信号变化规律

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交通运输工程学报 2024年第1期24卷 202-217页

作者：孟庆领杨家炳潘鹏超杨新磊王宝林宋金博天津城建大学土木工程学院天津300384 天津市交通科学研究院天津300060 江西交通职业技术学院路桥工程学院江西南昌330013 悉尼大学工程学院新南威尔士悉尼NSW 2006

为增强桥梁拉索高强钢丝漏磁检测的实用性,开展了腐蚀、应力单一因素作用试验与预腐蚀-疲劳-腐蚀、预疲劳-腐蚀-疲劳三阶段交互作用试验,阐述了腐蚀-疲劳耦合作用对自漏磁信号的影响机制。研究结果表明:腐蚀区域的自漏磁信号极值随腐蚀... 详细信息

为增强桥梁拉索高强钢丝漏磁检测的实用性,开展了腐蚀、应力单一因素作用试验与预腐蚀-疲劳-腐蚀、预疲劳-腐蚀-疲劳三阶段交互作用试验,阐述了腐蚀-疲劳耦合作用对自漏磁信号的影响机制。研究结果表明:腐蚀区域的自漏磁信号极值随腐蚀时间的增加而增加,且变化特征越发明显,腐蚀缺陷引起的异常自漏磁信号最大变化可达50 000 nT;随着疲劳加载循环次数的增加,无锈蚀高强钢丝自漏磁信号整体呈现先增加后稳定的趋势,当疲劳加载循环次数大于10 000时,磁场强度的增加速率降低且趋于平缓;预腐蚀后施加的交变应力场会削弱腐蚀缺陷引起的自漏磁信号,再次腐蚀后的磁场信号变化与预腐蚀程度有关,预腐蚀9 h后施加疲劳荷载,之后再腐蚀3 h,与单一腐蚀12 h相比,自漏磁信号强度削弱了32%;施加预疲劳交变应力场可强化磁场,导致腐蚀后自漏磁信号极值增加,当预疲劳加载循环次数从1 000增加至100 000时,自漏磁信号强度增大了30%。由此可见,早期腐蚀引起的高强钢丝异常自漏磁信号可被疲劳作用掩盖,考虑单一腐蚀与应力变化难以反映高强钢丝自漏磁检测效果,需综合考虑腐蚀-疲劳的耦合效应,以获得桥梁拉索高强钢丝自漏磁信号变化规律,从而为桥梁拉索无损检测提供分析依据。

关键词：桥梁工程桥梁拉索自漏磁检测高强钢丝无损检测腐蚀-疲劳耦合

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Fe-Mn系无镍低温钢研究进展

塑性工程学报 2024年第5期31卷 11-22页

作者：赵鑫磊周华生章小峰林方敏邢梅杨永安徽工业大学冶金工程学院安徽马鞍山243002

随着能源消耗和环境污染问题日益严峻,液化天然气等清洁能源得到广泛关注。低温钢作为这类能源存储和运输的材料,其应用和研发愈显迫切。Ni钢是低温结构钢的主流选择,但近年来,由于Fe-Mn系钢的经济性和性能的优良性,“以锰代镍”新型低... 详细信息

随着能源消耗和环境污染问题日益严峻,液化天然气等清洁能源得到广泛关注。低温钢作为这类能源存储和运输的材料,其应用和研发愈显迫切。Ni钢是低温结构钢的主流选择,但近年来,由于Fe-Mn系钢的经济性和性能的优良性,“以锰代镍”新型低温钢成为科研热点,该类钢通常通过添加Mn、Al和Cu等合金元素调控力学性能,并通过工艺调控达到使用标准。重点阐述了外力参数-变形对力学性能的影响、经典强化机制和变形对强韧性机制的影响;综述了裂纹萌生、溶质偏析、相间强度差和能量吸收等低温断裂的理论原理;系统归纳了韧性的评价指标和试验方法。最后,总结了Fe-Mn系低温钢的相关研究成果,对未来的研究进行了展望。

关键词：无镍低温钢成分工艺强韧化机制断裂机理

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翼身融合飞翼式水下滑翔机的水动力性能研究

舰船科学技术 2024年第6期46卷 90-97页

作者：熊仲营刘越尧雷新桃樊夏瑞江苏科技大学船舶与海洋工程学院江苏镇江212100

本文依据翼身融合式飞行器的设计理念设计一种飞翼式水下滑翔机,及其主要设计参数。通过计算发现该飞翼式水下滑翔机较传统水下滑翔机拥有更大的升阻比,可达到15以上。流场分布结果显示飞翼式水下滑翔机在特定速度0.1 m/s、0.3 m/s和0.5... 详细信息

本文依据翼身融合式飞行器的设计理念设计一种飞翼式水下滑翔机,及其主要设计参数。通过计算发现该飞翼式水下滑翔机较传统水下滑翔机拥有更大的升阻比,可达到15以上。流场分布结果显示飞翼式水下滑翔机在特定速度0.1 m/s、0.3 m/s和0.5 m/s下,机翼周围并未出现明显的流动分离,且机翼表面压力较大程度取决于攻角的大小。对比了不同雷诺数下的机翼表面涡脱落情况,发现随着攻角增大涡的脱落急剧增多,且翼梢小翼尾部涡脱落最为严重,极大影响滑翔机的水动力特性。

关键词：翼身融合式飞翼式水下滑翔机水动力性能升阻比涡量

Tension and Drag Forces of Flexible Risers Undergoing Vortex-Induced Vibration

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China Ocean Engineering 2017年第1期31卷 1-10页

作者： SONG lei-jian FU Shi-xiao LI Man GAO Yun MA lei-xin State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration Shanghai 200240China Marine Design & Research Institute of China Shanghai 200011China State Key Laboratory of Oil and Gas Reservoir Geology and Exploration Southwest Petroleum UniversityChengdu 610500China

This paper presents the results of an experimental investigation on the variation in the tension and the distribution of drag force coefficients along flexible risers under vortex-induced vibration（VIV） in a uniform flow for Reynolds numbers（Re） up to 2.2×10^5. The results show that the mean tension is proportional to the square of the incoming current speed, and the tension coefficient of a flexible riser undergoing VIV can be up to 12. The mean drag force is uniformly and symmetrically distributed along the axes of the risers undergoing VIV. The corresponding drag coefficient can vary between 1.6 and 2.4 but is not a constant value of 1.2, as it is for a fixed cylinder in the absence of VIV. These experimental results are used to develop a new empirical prediction model to estimate the drag force coefficient for flexible risers undergoing VIV for Reynolds number on the order of 10^5, which accounts for the effects of the incoming current speed, the VIV dominant modal number and the frequency.

关键词： Reynolds riser cylinder vortex Vortex hydrodynamic empirical turbulent averaged oscillating

基于主客观评价的社区生活圈公共服务设施优化策略研究——以南宁市中心城区为例

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上海城市规划 2024年第1期174卷 9-16页

作者：杨辰辛蕾欧阳宏梁立东朱敏吉同济大学建筑与城市规划学院上海市城市更新及其空间优化技术重点实验室同济大学建筑与城市规划学院南宁市城市规划编制研究中心南宁市建筑规划设计集团有限公司南宁市良庆区住房和城乡建设局

社区生活圈已成为当前“以人为本”理念下城市更新实施和评价的重要工具。然而传统的社区生活圈规划主要基于公共服务设施覆盖率和可达性等空间绩效评价方法,较少关注居民的实际生活体验和需求。以广西壮族自治区南宁市中心城区为例,通... 详细信息

社区生活圈已成为当前“以人为本”理念下城市更新实施和评价的重要工具。然而传统的社区生活圈规划主要基于公共服务设施覆盖率和可达性等空间绩效评价方法,较少关注居民的实际生活体验和需求。以广西壮族自治区南宁市中心城区为例,通过社区居民满意度调查,根据客观评价(设施服务水平)和主观评价(居民满意度)之间的相关性程度,将公共服务设施分为强相关、中等相关、弱相关和不相关4种类型;进而根据各类设施的相关性特征及潜在影响因素,结合典型社区生活圈实地调研,提出社区生活圈公共服务设施的分类优化策略,以期为全国其他城市提供可借鉴的经验。

关键词：主客观评价社区生活圈公共服务设施覆盖率满意度

Using concurrent lines in central catadioptric camera calibration

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第3期12卷 239-249页

作者： lei ZHANG xin DU Ji-lin LIU Department of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China

Central catadioptric cameras have been extensively adopted in robotics and surveillance due to their extensive field of *** attain precise 3D information in these applications,it is important to calibrate the catadioptric cameras *** existing calibration techniques either require prior knowledge of the mirror types,or highly depend on a conic estimation procedure,which might be ruined if there are only small portions of the conic visible on calibration *** this paper,we design a novel planar pattern with concurrent lines as a calibration rig,which is more robust in conic estimation since the relationship among lines is taken into *** on the line properties,we propose a rough-to-fine approach suitable for the new planar pattern to calibrate central catadioptric *** method divides the nonlinear optimization calibration problem into several linear sub-problems that are much more robust against *** calibration method can estimate intrinsic parameters and the mirror parameter simultaneously and accurately,without a priori knowledge of the mirror *** performance is demonstrated by both simulation and a real hyperbolic catadioptric imaging system.

关键词： Catadioptric Calibration Concurrent lines Conic estimation