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Body-force modeling considering induced upstream effects for a transonic compressor with total temperature distortion

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Chinese Journal of Aeronautics 2024年第6期37卷 7-19页

作者： Jiahui QIU chen YANG Wenqiang ZHANG min ZHANG Juan DU Digital Twin Research Center Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China School of Engineering and Science University of Chinese Academy of SciencesBeijing 100190China National Key Laboratory of Science and Technology on Advanced Light-duty Gas-turbine Chinese Academy of SciencesBeijing 100190China School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

To numerically study the impact of total temperature distortion on a transonic compressor with reduced computational costs,a Body-Force Model(BFM)is ***,the interactions between the distorted flow and the compressor are analyzed using full-annulus Unsteady Reynolds-Averaged Navier-Stokes(URANS)results and the orbit *** is found that the induced swirl distortion and the mass flux nonuniformity are intensified in the compressor upstream flow field.A correction factor is thus added to the BFM to account for the effect of the induced swirl,which is crucial for the accurate representation of distortion transfer in the ***,steady simulations with large-amplitude 180circumferential total temperature distortion are performed using the developed *** is shown that the distorted compressor map simulated with the BFM matches well with URANS *** circumferential phase shift of total temperature and the generation of the additional total pressure distortion across the rotor are in line with the time-averaged URANS flow *** compressor upstream effects on the distorted inflow can also be exactly *** above-mentioned results demonstrate the BFM developed in this paper can effectively capture the distorted flow features inside the compressor,and significantly reduce the computational costs by five orders of magnitude compared with URANS.

关键词： Upstream effect Orbit method Induced swirl distortion Body force model Correction factor Time-averaged URANS

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Hybrid 2D/3D Graphitic Carbon Nitride-Based High-Temperature Position-Sensitive Detector

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Energy & Environmental Materials 2024年第1期7卷 275-283页

作者： Xuexia chen Dongwen Yang Xun Yang Qing Lou Zhiyu Liu Yancheng chen Chaofan Lv Lin Dong Chongxin shan Henan Key Laboratory of Diamond Optoelectronic Materials and Devices Key Laboratory of Material PhysicsMinistry of EducationSchool of Physics and MicroelectronicsZhengzhou UniversityZhengzhou 450052China

Ultraviolet position-sensitive detectors(PSDs)are expected to undergo harsh environments,such as high temperatures,for a wide variety of applications in military,civilian,and ***,no report on relevant PSDs operating at high temperatures can be found up to ***,we design a new 2D/3D graphitic carbon nitride(g-C_(3)N_(4))/gallium nitride(GaN)hybrid heterojunction to construct the ultraviolet high-temperature-resistant *** g-C_(3)N_(4)/GaN PSD exhibits a high position sensitivity of 355 mV mm^(-1),a rise/fall response time of 1.7/2.3 ms,and a nonlinearity of 0.5%at room *** ultralow formation energy of-0.917 eV atom^(-1)has been obtained via the thermodynamic phase stability calculations,which endows g-C_(3)N_(4)with robust stability against *** merits of the strong built-in electric field of the 2D/3D hybrid heterojunction and robust thermo-stability of g-C_(3)N_(4),the g-C_(3)N_(4)/GaN PSD delivers an excellent position sensitivity and angle detection nonlinearity of 315 mV mm^(-1)and 1.4%,respectively,with high repeatability at a high temperature up to 700 K,outperforming most of the other counterparts and even commercial silicon-based *** work unveils the high-temperature PSD,and pioneers a new path to constructing g-C_(3)N_(4)-based harsh-environment-tolerant optoelectronic devices.

关键词： graphitic carbon nitride high-temperature stability lateral photovoltaic effect position-sensitive detectors two-dimensional materials

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Audio-guided self-supervised learning for disentangled visual speech representations

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Frontiers of Computer Science 2024年第6期18卷 186353-186353页

作者： FENG Dalu YANG Shuang shan Shiguang chen Xilin Key Laboratory of Intelligent Information Processing of Chinese Academy of Sciences Institute of Computing Technology Chinese Academy of Sciences University of Chinese Academy of Sciences

In this paper, we propose a novel two-branch framework to learn the disentangled visual speech representations based on two particular observations. Its main idea is to introduce the audio signal to guide the learning of speech-relevant cues and introduce a bottleneck to restrict the speech-irrelevant branch from learning high-frequency and fine-grained speech cues. Experiments on both the word-level and sentence-level audio-visual speech datasets LRW and LRS2-BBC show the effectiveness. Our future work is to explore more explicit auxiliary tasks and constraints beyond the reconstruction task of the speech-relevant and irrelevant branch to improve further its ability of capturing speech cues in the video. Meanwhile, it’s also a nice try to combine multiple types of knowledge representations [10] to further boost the obtained speech epresentations, which is also left for the future work.

关键词： Knowledge representation

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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

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Towards mixed physical node reservoir computing:light-emitting synaptic reservoir system with dual photoelectric output

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Light(Science & Applications) 2024年第9期13卷 1865-1877页

作者： minrui Lian Changsong Gao Zhenyuan Lin Liuting shan Cong chen Yi Zou Enping cheng Changfei Liu Tailiang Guo Wei chen Huipeng chen Institute of Optoelectronic Display National&Local United Engineering Lab of Flat Panel Display TechnologyFuzhou UniversityFuzhou 350002China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350100China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China Department of Chemistry National University of Singapore3 Science Drive 3Singapore 117543Singapore Department of Physics National University of Singapore3 Science Drive 3Singapore 117543Singapore

Memristor-based physical reservoir computing holds significant potential for efficiently processing complex spatiotemporal data,which is crucial for advancing artificial ***,owing to the single physical node mapping characteristic of traditional memristor reservoir computing,it inevitably induces high repeatability of eigenvalues to a certain extent and significantly limits the efficiency and performance of memristor-based reservoir computing for complex ***,this work firstly reports an artificial light-emitting synaptic(LES)device with dual photoelectric output for reservoir computing,and a reservoir system with mixed physical nodes is *** system effectively transforms the input signal into two eigenvalue outputs using a mixed physical node reservoir comprising distinct physical quantities,namely optical output with nonlinear optical effects and electrical output with memory *** previously reported memristor-based reservoir systems,which pursue rich reservoir states in one physical dimension,our mixed physical node reservoir system can obtain reservoir states in two physical dimensions with one input without increasing the number and types of *** recognition rate of the artificial light-emitting synaptic reservoir system can achieve 97.22%in MNIST ***,the recognition task of multichannel images can be realized through the nonlinear mapping of the photoelectric dual reservoir,resulting in a recognition accuracy of 99.25%.The mixed physical node reservoir computing proposed in this work is promising for implementing the development of photoelectric mixed neural networks and material-algorithm collaborative design.

关键词： reservoir mixed system

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Changes in Leaf Stomatal Properties in Rice with the Growing Season

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Phyton-International Journal of Experimental Botany 2024年第4期93卷 807-817页

作者： Jiana chen Fangbo Cao min Huang Rice and Product Ecophysiology Key Laboratory of Ministry of Education for Crop Physiology and Molecular BiologyHunan Agricultural UniversityChangsha410128China National Engineering Research Center of Rice Hunan Agricultural UniversityChangsha410128China

Transplanting rice varieties grown in different seasons can lead to different yields due to different dry matterproduction. Early-season rice varieties transplanted in the late season can obtain high yields with short-growthduration and higher yields driven by higher dry matter production. To make clear the variations in dry matterproduction across seasons, four early-season rice varieties were chosen for late-season transplantation. The grainyield, dry matter accumulation, leaf photosynthetic, and leaf stomatal properties were studied. It was observedthat the average yields of these four varieties in the late season were 33% greater, despite a reduced growth periodof 13 days in comparison with the early season. Furthermore, there was a notable increase in both total and postheadingdry matter production during the late season. The leaf net photosynthetic rate, stomatal area, stomatalwidth, and stomatal length were higher in the late season. Despite no significant difference in stomatal densitybetween seasons, strong positive linear relationships were observed between net photosynthetic rate and stomatalconductance, and between stomatal conductance and area. These relationships demonstrate that the increase ofthe stomatal width and length of the leaves in the late season leads to an increase in the stomatal area, therebyincreasing the stomatal conductance and enhancing the photosynthesis of the leaves. Consequently, this leads togreater dry matter production and a higher yield compared to the early season. Therefore, when breeding newhigh-yielding and short-growing varieties, the large stomatal area can be used as a reference index.

关键词： Photosynthesis rice stomatal properties season yield

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A versatile volume-based modeling technique of distributed local quadratic convergence for aeroengines

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Propulsion and Power Research 2024年第1期13卷 46-63页

作者： Yudong Liu min chen Hailong Tang School of Energy and Power Engineering Beihang UniversityBeijing 100191China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China

For advanced aero-engine design and research,modeling and simulation in a digital environment is indispensable,especially for engines of complicated conﬁgurations,such as var-iable cycle engines(VCE)and adaptive cycle engines(ACE).Also,in the research of future smart engines,reliable real-time digital twins are ***,the 2 dominant methods that used in solving the simulation models,Newton-Raphson(N-R)method and volume-based method,are not fully qualiﬁed for the study requirements,because neither of them reaches the satisfactory balance of convergence rate and calculating efﬁ*** this study,by deeply analyzing the mathematical principle of these 2 methods,a novel modeling and solving method for aero-engine simulation,which integrates the advantages of both N-R and volume-based methods,is *** has distributed architecture and local quadratic convergence *** a novel modeling method for variable area bypass injectors(VABI)is put *** facilitate simulation of various conﬁgurations of *** modeling cases,including a high bypass-ratio(BPR)turbofan and an ACE,illustrate that the novel technique decreases the iterations by about two-thirds comparing with volume-based method,while the success rate of convergence remains over 99%.This proves its superiority in both convergence and calculating efﬁciency over the conventional *** technique can be used in advanced gas turbine en-gine design and control strategy optimization,and study of digital twins.

关键词： Aero-engine performance simulation Variable cycle engine Variable area bypass injector Digital twin Newton-Raphson method

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Lewis Base Catalyzed Selenofunctionalization of Alkynes with Acid-Controlled Divergent Chemoselectivity

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Chinese Journal of Chemistry 2024年第14期42卷 1623-1629页

作者： Ling-Ling chen Ren-Fei Cao Hua Ke Zhi-min chen School of Chemistry and Chemical Engineering Shanghai Key Laboratory for Molecular Engineering of Chiral DrugsShanghai Jiao Tong UniversityShanghai200240 China Engineering Technology Research Center for Environmental Protection Materials Pingxiang UniversityPingxiangJiangxi337055 China

Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first *** selenium-containing tetrasubstituted alkenes were readily obtained in moderate to excellent yields with complete E/Z *** the substrates were 1-ethynyl naphthol derivatives,linear selenium-containing tetrasubstituted alkenes were produced via intermolecular oxygen nucleophilic attack in the absence of acid additive;in contrast,cyclic selenium-containing tetrasubstituted alkenes were generated through intramolecular carbon nucleophilic capture with the addition of Brønsted acid.

关键词： Alkynes Electrophilic addition Chemoselectivity Lewis base catalysis Selenofunctionalization

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How mesenchymal stem cells transform into adipocytes:Overview of the current understanding of adipogenic differentiation

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World Journal of Stem Cells 2024年第3期16卷 245-256页

作者： shan-shan Liu Xiang Fang Xin Wen Ji-shan Liu Miribangvl Alip Tian Sun Yuan-Yuan Wang Hong-Wei chen Department of Reumatology and Immunology Nanjing Drum Tower HospitalThe Affiliated Hospital of Medical SchoolNanjing UniversityNanjing 210008Jiangsu ProvinceChina Department of Emergency Nanjing Drum Tower HospitalThe Affiliated Hospital of Medical SchoolNanjing UniversityNanjing 210008Jiangsu ProvinceChina Key Laboratory for Biomechanics and Mechanobiology of ministry of Education School of Biological Science and Medical EngineeringBeihang UniversityBeijing 100191China Anhui Key Laboratory of Infection and Immunity Bengbu Medical CollegeBengbu 233000Anhui ProvinceChina

Mesenchymal stem cells(MSCs)are stem/progenitor cells capable of self-renewal and differentiation into osteoblasts,chondrocytes and *** transformation of multipotent MSCs to adipocytes mainly involves two subsequent steps from MSCs to preadipocytes and further preadipocytes into adipocytes,in which the process MSCs are precisely controlled to commit to the adipogenic lineage and then mature into *** studies have shown that the master transcription factors C/enhancer-binding protein alpha and peroxisome proliferation activator receptor gamma play vital roles in ***,the mechanism underlying the adipogenic differentiation of MSCs is not fully ***,the current knowledge of adipogenic differentiation in MSCs is reviewed,focusing on signaling pathways,noncoding RNAs and epigenetic effects on DNA methylation and acetylation during MSC ***,the relationship between maladipogenic differentiation and diseases is briefly *** hope that this review can broaden and deepen our understanding of how MSCs turn into adipocytes.

关键词： Mesenchymal stem cell Adipogenic differentiation Signaling pathway Noncoding RNA Epigenetic regulation

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Constructing energetic covalent organic frameworks with high stability and low sensitivity

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Chinese Chemical Letters 2024年第3期35卷 544-548页

作者： Hui-min Guo Xiao-Yu Dong shan Wang Qian-You Wang Shuang-Quan Zang Henan Key Laboratory of Crystalline Molecular Functional Materials Green Catalysis Centerand College of ChemistryZhengzhou UniversityZhengzhou 450001China

Developing new functional explosives that display high stability,good energy performance,and low sensitivity are one of the key directions of energetic materials *** this work,two-dimensional(2D)Schiff-based energetic covalent organic frameworks(COFs)are prepared based on triaminoguanidine salts with different anions as building *** from the robust covalent bond in 2D extended polygons and strongπ-πinteractions in the eclipsed interlayers,the synthesized energetic COFs showed higher thermal stability and lower mechanical sensitivity than their precursor *** importantly,incorporating triaminoguanidine salts into COFs effectively increase the corrosion resistance to metal under high humidity conditions,which is due to the imine moieties in COFs functioning asπacceptors and offering strong bonding with metallic *** work provides a new pathway for the development of high-performance energetic materials.

关键词： Covalent organic frameworks Energetic materials High thermal stability Low sensitivity Corrosion resistance

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