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Aerodynamic Performance of Three Flapping Wings with Unequal Spacing in Tandem Formation

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Journal of Bionic Engineering 2024年第4期21卷 1662-1676页

作者： Min chang Ziyi Xu Zengshuang chen li li Xueguang Meng Unmanned System Research Institute National Key Laboratory of Unmanned Aerial Vehicle TechnologyNorthwestern Polytechnical UniversityXi’an710072People’s Republic of China State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an710049People’s Republic of China Xi’an Aeronautics Computing Technique Research Institute Aviation Industry Corporation of ChinaXi’an710076People’s Republic of China

To better understand the aerodynamic reasons for highly organized movements of flying organisms,the three-flapping wing system in tandem formation was studied numerically in this *** from previous relevant studies on the multiple flapping wings that are equally spaced,this study emphasizes the impact of unequal spacing between individuals on the aerodynamics of each individual wing as well as the whole *** is found that swapping the distance between the first and second wing with the distance between the second wing and the rearmost wing does not affect the overall aerodynamic performance,but significantly changes the distribution of aerodynamic benefits across each *** the whole flapping cycle,three effects are at *** narrow channel effect and the downwash effect can promote and weaken the wing lift,respectively,while the wake capture effect can boost the *** also shows that these effects could be manipulated by changing the spacing between adjacent *** findings provide a novel way for flow control in tandem formation flight and are also inspiring for designing the formation flight of bionic aircraft.

关键词： Three flapping wings Unequal spacing Aerodynamic performance Tandem formation

Effect of droplet characteristics on liquid-phase distribution in spray zone of internal mixing air-mist nozzle

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China Foundry 2024年第2期21卷 185-196页

作者： Wei-li Wu chang-gui cheng Yang li Shi-fa Wei De-li chen The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081China Technology Center Fushun Special Steel Co.Ltd.Fushun 113001LiaoningChina

In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab *** order to study the behavior of atomized droplets after reaching the slab surface and to optimize the spray cooling effect,the influence of droplet diameter and droplet velocity on the migration behavior of droplets in the secondary cooling zone was analyzed by FLUENT *** show that the droplets in the spray zone and on the slab surface are mainly concentrated in the center,thus,the liquid volume fraction in the center is higher than that of either *** the droplet diameter increases,the region of high liquid volume fraction on the slab surface becomes wider,and the liquid phase distribution in the slab width direction becomes *** increasing the droplet velocity at the nozzle exit has little effect on droplet diffusion in the spray zone,the distribution becomes more uneven due to more liquid reaches the slab surface per unit time.A prediction formula of the maximum water flow rate on the slab surface for specific droplet characteristics was proposed based on dimensionless analysis and validated by simulated data.A nozzle spacing of 210 mm was recommended under the working conditions in this study,which ensures effective coverage of the spray water over the slab surface and enhances the distribution uniformity of water flow rate in the transverse direction.

关键词： continuous casting secondary cooling zone internal mixing air-mist nozzle droplet characteristics liquid phase distribution water flow rate

Atomically Dispersed Ruthenium Catalysts with Open Hollow Structure for lithium-Oxygen Batteries

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Nano-Micro Letters 2024年第2期16卷 154-164页

作者： Xin chen Yu Zhang chang chen Huinan li Yuran lin Ke Yu Caiyun Nan chen chen Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Solid State ChemistryUniversity of Science and Technology BeijingBeijing 100083People’s Republic of China Engineering Research Center of Advanced Rare Earth Materials Department of ChemistryTsinghua UniversityBeijing 100084People’s Republic of China Beijing Key Laboratory of Energy Conversion and Storage Materials Institution College of ChemistryBeijing Normal UniversityBeijing 100875People’s Republic of China

lithium–oxygen battery with ultrahigh theoretical energy density is considered a highly competitive next-generation energy storage device,but its practical application is severely hindered by issues such as difficult decomposition of discharge products at ***,we have developed N-doped carbon anchored atomically dispersed Ru sites cathode catalyst with open hollow structure(h-RuNC)for lithium–oxygen *** one hand,the abundance of atomically dispersed Ru sites can effectively catalyze the formation and decomposition of discharge products,thereby greatly enhancing the redox *** the other hand,the open hollow structure not only enhances the mass activity of atomically dispersed Ru sites but also improves the diffusion efficiency of catalytic ***,the excellent activity from atomically dispersed Ru sites and the enhanced diffusion from open hollow structure respectively improve the redox kinetics and cycling stability,ultimately achieving a high-performance lithium–oxygen battery.

关键词： Atomically dispersed Open hollow structure Discharge product lithium Oxygen battery

Near-infrared non-fused electron acceptors for efficient organic photovoltaics

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Chinese Chemical Letters 2024年第4期35卷 436-441页

作者： Wenxiang Ma Xinyu He Tianyi chen De-li Ma Hongzheng chen chang-Zhi li State Key Laboratory of Silicon and Advanced Semiconductor Materials Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China

Developing narrow-bandgap organic semiconductors is important to facilitate the advancement of organic photovoltaics(OPVs). Herein, two near-infrared non-fused ring acceptors(NIR NFRAs), PTBFTT-F and PTBFTT-Cl have been developed with A-π_A-π_D-D-π_D-π_A-A non-fused structures. It is revealed that the introduction of electron deficient π-bridge(π_A) and multiple intramolecular noncovalent interactions effectively retained the structural planarity and intramolecular charge transfer of NFRAs, extending strong NIR photon absorption up to 950 nm. Further, the chlorinated acceptor, with the enlarged π-surface compared to the fluorinated counterpart, promoted not only molecular stacking in solid, but also the desirable photochemical stability in ambient, which are helpful to thereby improve the exciton and charge dynamics for the corresponding OPVs. Overall, this work provides valuable insights into the design of NIR organic semiconductors.

关键词： Organic photovoltaic Near-infrared Non-fused electron acceptor Noncovalent interaction Stability

Enhancement of low-temperature toughness of Fe-Mn-C-Al alloy by rare earth Ce-modified inclusions

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Journal of Iron and Steel Research International 2024年第1期31卷 157-173页

作者： Guang-kai Yang chang-ling Zhuang Yi-zhuang li chen Hu Shao-bo li College of Materials and Metallurgy Guizhou UniversityGuiyang550025GuizhouChina Department of Mechanical Engineering University of Hong KongHong Kong999077China The State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina State Key Laboratory of Public Big Data Guizhou UniversityGuiyang550025GuizhouChina

Fe-Mn-C-Al alloys have been recognized as promising materials for certain low-temperature applications due to their exceptional mechanical properties and ***,their limited low-temperature toughness restricts their large-scale applications in specific *** influence of trace amounts of rare earth cerium(Ce)on the low-temperature toughness of Fe-18Mn-0.6C-1.8Al alloys was *** addition of Ce effectively alters the inclu-sions in the alloy,transforming large-sized irregular inclusions into fine ellipsoidal rare earth *** leads to a significant reduction in both the proportion and average size of the inclusions,resulting in their effective dispersion throughout the matrix and improved cryogenic *** presence of Ce-containing inclusions within the matrix reduces stress concentration,thereby inhibiting microcrack formation and improving impact absorption ***-cally,the addition of rare earth Ce alters the fracture behavior of the material at room temperature and low temperature,changing from brittle cleavage fracture to a more ductile failure *** impact toughness of the Fe-Mn-C-Al alloy is significantly improved by the addition of 0.0048 wt.%Ce,particularly at-196℃where the impact toughness reaches 103.6 J/cm^(2),representing an impressive improvement of 87.3%.

关键词： Fe-Mn-C-Al alloy Rare earth Low-temperature toughness Inclusion Fracture

Enhanced mechanical property by introducing bimodal grains structures in Cu-Ta alloys fabricated by mechanical alloying

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Journal of Materials Science & Technology 2024年第5期172卷 104-112页

作者： Ningyu li Yongqin chang Mingyang li Yuxiang chen Xinrui Luo Shichao Pei Fan Yang School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Xi’an Rare Metal Materials Institute Co.Ltd Xi’an 710016China

Dispersion-strengthened copper alloys can achieve ultra-high strength,but usually at the expense of *** this study,a strategy for overcoming strength-ductility tradeoffof Cu alloys is realized through the introduction of bimodal grains ***-Ta alloys with only 0.5 at.%Ta content were successfully prepared by mechanical alloying combined with spark plasm *** samples prepared by one-step and two-step ball milling methods are named as Cu-Ta(Ⅰ)and Cu-Ta(Ⅱ),*** microstructural characterizations revealed that ultra-fine equiaxed grains with uniformly dispersed Ta precipitates were obtained in the Cu-Ta *** strength of 377 MPa for yield strength together with elongation of∼8%was obtained in Cu-Ta(Ⅰ).Bimodal grains structures composed of fine-grain zones and coarse-grain zones were successfully introduced into Cu-Ta(Ⅱ)by a two-step ball milling approach,and both yield strength(463 MPa)and elongation(∼15%)were significantly synergistic *** hardness values of both Cu-Ta(Ⅰ)and Cu-Ta(Ⅱ)were almost kept nearly constant with the increase of annealing time,and the softening temperatures of Cu-Ta(Ⅰ)and Cu-Ta(Ⅱ)are 1018 and 1013℃,reaching 93.9%and 93.5%T m of pure Cu(1083℃),*** reveals that the Cu-0.5 at.%Ta alloys exhibit excellent thermal stability and exceptional softening *** nanoclusters with semi-coherent structures play an essential role in enhancing the strength and microstructural stability of *** structures are beneficial to the activation of back stress strengthening and the initiation and propagation of microcracks,thus obtaining the extraordinary combination of strength and *** study provides a new way to fabricate dispersion-strengthened Cu alloys with high strength,high elongation,excellent thermal stability and softening resistance,which have potential application value in the field of the future fusion reactor.

关键词： Cu-Ta alloy Mechanical alloying Ta precipitates Bimodal structures Mechanical property

Unraveling the complex roles of macrophages in obese adipose tissue:an overview

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Frontiers of Medicine 2024年第2期18卷 205-236页

作者： chang Peng Jun chen Rui Wu Haowen Jiang Jia li Hangzhou Institute for Advanced Study University of Chinese Academy of SciencesHangzhou310000China State Key Laboratory of Drug Research Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai201203China University of Chinese Academy of Sciences Beijing100049China Department of Prosthodontics Shanghai Engineering Research Center of Advanced Dental Technology and MaterialsShanghai Key Laboratory of Stomatology&Shanghai Research Institute of StomatologyNational Clinical Research Center for Oral DiseasesShanghai Ninth People’s HospitalCollege of StomatologyShanghai Jiao Tong University School of MedicineShanghai200011China

Macrophages,a heterogeneous population of innate immune cells,exhibit remarkable plasticity and play pivotal roles in coordinating immune responses and maintaining tissue homeostasis within the context of metabolic *** activation of inflammatory macrophages in obese adipose tissue leads to detrimental effects,inducing insulin resistance through increased inflammation,impaired thermogenesis,and adipose tissue ***,adipose tissue macrophages also play a beneficial role in maintaining adipose tissue homeostasis by regulating angiogenesis,facilitating the clearance of dead adipocytes,and promoting mitochondrial *** the heterogeneity of macrophages in obese adipose tissue is crucial for unraveling the pathogenesis of obesity and holds significant potential for targeted therapeutic ***,the dual effects and some potential regulatory mechanisms of macrophages in adipose tissue have been elucidated using single-cell *** this review,we present a comprehensive overview of the intricate activation mechanisms and diverse functions of macrophages in adipose tissue during obesity,as well as explore the potential of drug delivery systems targeting macrophages,aiming to enhance the understanding of current regulatory mechanisms that may be potentially targeted for treating obesity or metabolic diseases.

关键词： obesity inflammation adipose tissue macrophages adipose tissue homeostasis

Deep learning-based optical aberration estimation enables offline digital adaptive optics and super-resolution imaging

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Photonics Research 2024年第3期12卷 474-484页

作者： chang QIAO HAOYU chen RUN WANG TAO JIANG YUWANG WANG DONG li Department of Automation Tsinghua UniversityBeijing 100084China Institute for Brain and Cognitive Sciences Tsinghua UniversityBeijing 100084China National Laboratory of Biomacromolecules New Cornerstone Science LaboratoryCAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of SciencesBeijing 100101China College of life Sciences University of Chinese Academy of SciencesBeijing 100049China Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China

Optical aberrations degrade the performance of fluorescence *** adaptive optics(AO)leverages specific devices,such as the Shack–Hartmann wavefront sensor and deformable mirror,to measure and correct optical ***,conventional AO requires either additional hardware or a more complicated imaging procedure,resulting in higher cost or a lower acquisition *** this study,we proposed a novel space-frequency encoding network(SFE-Net)that can directly estimate the aberrated point spread functions(PSFs)from biological images,enabling fast optical aberration estimation with high accuracy without engaging extra optics and image *** showed that with the estimated PSFs,the optical aberration can be computationally removed by the deconvolution ***,to fully exploit the benefits of SFE-Net,we incorporated the estimated PSF with neural network architecture design to devise an aberration-aware deeplearning super-resolution model,dubbed *** demonstrated that the combination of SFE-Net and SFT-DFCAN enables instant digital AO and optical aberration-aware super-resolution reconstruction for live-cell imaging.

关键词： optics resolution enable

Comprehensive evaluation of an ionic liquid based deep purification process for NH_(3)-containing industrial gas

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Journal of Environmental Sciences 2024年第2期136卷 698-708页

作者： Guoxiong Zhan Fei Cao Jianjun chen Zhen chen Yuanmeng Duan Fei chang Shaojuan Zeng Yinge Bai Zengxi li Xiangping Zhang Junhua li State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China Sino-Danish College University of Chinese Academy of SciencesBeijing 100049China Institute of Process Engineering Chinese Academy of SciencesBeijing 100190China College of Chemical and Engineering University of Chinese Academy of SciencesBeijing 100049China

Ammonia(NH_(3))emission has caused serious environment issues and aroused worldwide *** emerging ionic liquid(IL)provides a greener way to efficiently capture NH_(3).This paper provides rigorous process simulation,optimization and assessment for a novel NH_(3)deep purification process using *** process was designed and investigated by simulation and optimization using ionic liquid[C_(4)im][NTF_(2)]as *** objective functions,total purification cost(TPC),total process CO_(2)emission(TPCOE)and thermal efficiency(ηeff)were employed to optimize the absorption *** simulation and optimization results indicate that at same purification standard and recovery rate,the novel process can achieve lower cost and CO_(2)emission compared to benchmark *** process optimization,the optimal functions can achieve 0.02726$/Nm~3(TPC),311.27 kg CO_(2)/hr(TP-COE),and 52.21%(ηeff)for enhanced ***,compared with conventional process,novel process could decrease over$3 million of purification cost and 10000 tons of CO_(2)emission during the life *** results provide a novel strategy and guidance for deep purification of NH_(3)capture.

关键词： NH_(3) Capture Process Ionic liquid Process Simulation Process Optimization Deep purification