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reynolds-number scaling analysis on lift generation of a flapping and passive rotating wing with an inhomogeneous mass distribution

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Chinese journal of Aeronautics 2024年第2期37卷 259-269页

作者： Suyang QIN Haotian HANG yang XIANG Hong LIU j.C.Wu center for aerodynamics school of aeronautics and astronauticsshanghai jiao tong universityshanghai 200240china

Insects usually fly by passively rotating wings,which has been applied to the design of flapping-wing Micro-Air Vehicles(MAVs)to reduce mechanical *** this paper,a robotic passive rotating-wing model is designed to investigate wing kinematics and lift generation,which are measured by a high-speed camera and a force transducer,*** addition,flow fields are measured using the Particle Image Velocimetry(PIV).Experimental results demonstrate that passive rotating motion has a coordinative relationship with actively stroking *** the stroke amplitude or frequency increases,the rotating amplitude is *** characterize the active stroking motion,a driving reynolds number redrivingis defined,which varies from 68 to 366 in this *** the gravity center of the wing towards trailing ed ge induces the increase of additional torque M,which decreases the wing rotating amplitude and promotes the advance of wing *** find that the timing of wing rotation is gradually delayed and the mean lift coefficient C^(-)_(L)monotonously decreases as *** increasing the additional torque M,C^(-)_(L)is slightly improved and approaches to the lift coefficient of a real fruit fly at driving re approximately equal to *** instantaneous lifts combined with the vortical structures further demonstrate that the lift generation associated with wing rotation is mainly attributed to the growth of the LeadingEdge Vortex(LEV)and the passive wake capture *** wake capture is influenced by LEV,reversal stroke motion and wing additional torque together,which can only maintain the lift at a high level for a considerable *** high-lift generation mechanisms of flapping and passive rotating flight could shed light on the simplified design of MAVs and the improvement of their aerodynamic performance.

关键词： Flapping flight Unsteady lift Passive rotation Vortex flow Leading-edge vortex

The photo-decomposition and self-restructuring dynamic equilibrium mechanism of Cu_(2)(OH)_(2)CO_(3)for stable photocatalytic CO_(2)reduction

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journal of Energy Chemistry 2024年第5期92卷 104-112页

作者： Yaqing Zhi Haoning Mao Guangxing yang Qiao Zhang Zhiting Liu Yonghai Cao Siyuan yang Feng Peng School of Chemistry and Chemical Engineering Guangzhou UniversityGuangzhou 510006GuangdongChina College of Materials and Energy South China Agricultural UniversityGuangzhou 510642GuangdongChina School of Chemistry and Chemical Engineering South China University and TechnologyGangzhou 510640GuangdongChina

Developing suitable photocatalysts and understanding their intrinsic catalytic mechanism remain key challenges in the pursuit of highly active,good selective,and long-term stable photocatalytic CO_(2)reduction(PCO_(2)r)***,monoclinic Cu_(2)(OH)_(2)CO_(3)is firstly proven to be a new class of photocatalyst,which has excellent catalytic stability and selectivity for PCO_(2)r in the absence of any sacrificial agent and *** on a Cu_(2)(OH)_(2)^(13)CO_(3)photocatalyst and 13CO_(2)two-sided^(13)C isotopic tracer strategy,and combined with in situ diffused reflectance infrared Fourier transform spectroscopy(DrIFTS)analysis and density functional theory(DFT)calculations,two main CO_(2)transformation routes,and the photo-decomposition and self-restructuring dynamic equilibrium mechanism of Cu_(2)(OH)_(2)CO_(3)are definitely *** PCO_(2)r activity of Cu_(2)(OH)_(2)CO_(3)is comparable to some of state-of-the-art novel ***,the PCO_(2)r properties can be further greatly enhanced by simply combining Cu_(2)(OH)_(2)CO_(3)with typical TiO_(2)to construct composites *** highest CO_(2)and CH_(4)production rates by 7.5 wt%Cu_(2)(OH)_(2)CO_(3)-TiO_(2)reach 16.4μmol g^(-1)h^(-1)and 116.0μmol g^(-1)h^(-1),respectively,which are even higher than that of some of PCO_(2)r systems containing sacrificial agents or precious metals modified *** work provides a better understanding for the PCO_(2)r mechanism at the atomic levels,and also indicates that basic carbonate photocatalysts have broad application potential in the future.

关键词： CO_(2)photocatalytic reduction Photocatalysis Basic copper carbonate Self-reconstruction Photocatalyst

Congener-derived template to construct lithiophilic organic-inorganic layer/interphase for high volumetric capacity dendrite-free Li metal batteries

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Chinese Chemical Letters 2024年第3期35卷 453-460页

作者： Kang yang Long Li Yuanbin Xiao Qiaoli Zhang Chenpeng Xi Borong Li Yan Yu Chengkai yang Key Laboratory of Advanced Materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesCollege of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China

The development of lithium-metal batteries(LMBs)is seriously restricted by the out-of-control dendrites growth and infinite volume ***,a pervasive organic-inorganic layer construction strategy is reported for the composite lithium metal anode with congener-derived organic-inorganic solid electrolyte interphase(SEI).In this strategy,the organic-inorganic Ag@polydopamine(Ag@PDA)layer is coated on the arbitrary substrates by a simple two-step *** thin and stable congener-derived SEI is insitu formed with fewer inorganic components and more organic components during charging/*** polydopamine with sufficient adhesion groups and lithiophilic Ag layer realize near-zero nucleation overpotential during lithium *** low interface resistance and stable lithium deposition are ***,the practical areal and volumetric capacities of the composite anode with three-dimensional copper(3DCu)as the substrate are 10 mAh/cm^(2)and 1538 mAh/cm^3(*** mass of anode).The symmetrical cell shows very low polarization voltage(10 mV)and more than 2500 h cycles life at 1 mA/cm^(2)(1 mAh/cm^(2)).The LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)-based full cells show improved capacity retention(82%)after 100 cycles at 0.5 *** modified lithiophilic anode with congener-derived interphase provides a promising strategy to realize the next-generation dendrite-free LMBs.

关键词： Lithium metal anode Congener-derived Lithiophilicity Volumetric capacity Organic-inorganic interphase

Stand dynamics of old-growth hemlock forests in central Bhutan are shaped by natural disturbances

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Forest Ecosystems 2024年第4期11卷 434-447页

作者： Karma Tenzin Craig r.Nitschke Kathryn j.Allen raphael Trouve Thiet V.Nguyen Patrick j.Baker School of Agriculture Foodand Ecosystem SciencesUniversity of Melbourne500 Yarra BlvdRichmondVictoriaAustralia School of Geography Planningand Spatial SciencesUniversity of TasmaniaSandy BayTasmaniaAustralia Forest Science Institute of South Vietnam 1 Pham Van Hai StreetTan Binh DistrictHo Chi Minh CityViet Nam

Understanding how past disturbances have influenced the development of forests is critical for deciphering their current structure and composition and forecasting future *** this study,dendrochronological methods were applied to uncover the disturbance history of old-growth hemlock-dominated forests in central *** of tree-ring samples from two old-growth hemlock stands,located in two different topographic settings,identified the importance of gap-phase dynamics in facilitating recruitment and growth releases and producing complex,multi-aged structure s over *** site showed evidence of a near stand-replacing disturbance in the late 1700s,while the other showed no evide nce of high-severity disturbance at any time over the last 400 *** both sites low-to medium-severity disturbances,some of which appear to be associated with cyclones originating in the Bay of Bengal,dominated the disturbance *** hemlock stands exhibited a significant positive association between cyclone occurrence and growth release events and between recruitment pulses and growth release *** 1800 to 1970 there was an increase in recruitment of angiosperm tree species at most sites and a corresponding decline in conifer *** the past 50 years there has been little new recruitment;this may be due to light limitation in the understory from shade-tolerant angiosperms and bamboo in the lower strata of these *** variations in disturbance dynamics and recruitment were observed across the study sites,suggesting that other factors,such as topography and climate,may be influencing long-term stand development *** study highlights the complex interplay between historical disturbance regimes and tree recruitment in shaping the age and size structures of old-growth hemlock forests in central *** also provides new insights into the dynamics of these forests that can be used to support effective forest conservation and management i

关键词： Forest structure Hemlock forest Himalaya Natural disturbance

recent Ventures in Interdisciplinary Arctic research:The ArCPATH Pr.j.ct

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Advances in Atmospheric Sciences 2024年第8期41卷 1559-1568页

作者： Astrid E.j.OGILVIE Leslie A.KING Noel KEENLYSIDE François COUNILLON Brynhildur DAVIÐSDÓTTIr Níels EINArSSON Sergey GULEV Ke FAN Torben KOENIGK james r.MCGOODWIN Marianne H.rASMUSSON Shuting yang Institute of Arctic and Alpine research(INSTAAr) University of ColoradoBoulder CO 80303USA Stefansson Arctic Institute AkureyriÍS-600Iceland royal roads University BC V9B 5Y2Canada University of Bergen Bergen N-5007Norway Nansen Environmental and remote Sensing Centre Bergen N-5007Norway University of Iceland Reykjavík 102Iceland Shirshov Institute of Oceanology Moscow 117218Russia Moscow State University Moscow 11991Russia Chinese Academy of Sciences Beijing 100045China Swedish Meteorological and Hydrological Institute SE-60176 NorrköpingSweden Danish Meteorological Institute CopenhagenØ2100Denmark Obukhov Institute of Atmospheric Physics RAS119017MoscowRussia

This paper celebrates Professor Yongqi GAO's significant achievement in the field of interdisciplinary studies within the context of his final research pr.j.ct Arctic Climate Predictions: Pathways to resilient Sustainable Societies-ArCPATH(https://***/en/pr.j.cts/finished-pr.j.cts/arcpath). The disciplines represented in the pr.j.ct are related to climatology, anthropology, marine biology, economics, and the broad spectrum of social-ecological studies. Team members were drawn from the Nordic countries, russia, China, the United States, and Canada. The pr.j.ct was transdisciplinary as well as interdisciplinary as it included collaboration with local knowledge holders. ArCPATH made significant contributions to Arctic research through an improved understanding of the mechanisms that drive climate variability in the Arctic. In tandem with this research, a combination of historical investigations and social, economic, and marine biological fieldwork was carried out for the pr.j.ct study areas of Iceland, Greenland, Norway, and the surrounding seas, with a focus on the joint use of ocean and sea-ice data as well as social-ecological drivers. ArCPATH was able to provide an improved framework for predicting the near-term variation of Arctic climate on spatial scales relevant to society, as well as evaluating possible related changes in socioeconomic realms. In summary, through the integration of information from several different disciplines and research approaches, ArCPATH served to create new and valuable knowledge on crucial issues, thus providing new pathways to action for Arctic communities.

关键词： recent Ventures in Interdisciplinary Arctic research:The ArCPATH Pr.j.ct

Design and fabrication of self-suspending aluminum-plastic/semiconductor photocatalyst devices for solar energy conversion

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journal of Environmental Sciences 2024年第2期136卷 615-625页

作者： Zhi-Ang Zhao jingyun Mao Chengjing Lu Shuangqiao yang Qingrong Qian Qinghua Chen Hun Xue Xiaoli Sun Min-Quan yang College of Environmental and resource Sciences College of Carbon Neutral Modern IndustryFujian Key Laboratory of Pollution Control and Resource ReuseFujian Normal UniversityFuzhou 350007China State Key Laboratory of Polymer Materials Engineering Polymer Research Institute of Sichuan UniversityChengdu 610065China

The design and synthesis of self-suspending photocatalyst device with easy recyclability is important for practical ***,this work utilizes aluminum-plastic package waste as raw material to prepare an aluminum-plastic supported TiO_(2)(AP-TiO_(2))photocatalyst device through 3D printing design and surface deposition method.A series of characterizations were carried out to explore the structure,morphology and performance of the AP-TiO_(2)*** UV light illumination,the AP-TiO_(2)-50 efficiently degrade 93.6%tetracycline hydrochloride(THC)after 4 hr,which increases by 8.3%compared with that of TiO_(2)powder suspension system with the same catalyst *** on it,AP-ZnO,AP-CdS,AP-g-C_3N_4and AP-Pt-TiO_(2)are also fabricated,and applied in photocatalytic degradation and hydrogen evolution,which all exhibit higher photoactivities than powder suspension *** work provides a new avenue for the fabrication of advanced recyclable photocatalyst ***,the work offers a novel sight for the high-value utilization of aluminum-plastic package waste,which has positive implications for environmental protection.

关键词： TiO_(2) Self-suspending Photocatalyst device Aluminum plastic

Phytic acid-derivative Co_(2)B-CoPO_x coralloidal structure with delicate boron vacancy for enhanced hydrogen generation from sodium borohydride

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Chinese Chemical Letters 2024年第4期35卷 525-531页

作者： Luyan Shi Ke Zhu Yuting yang Qinrui Liang Qimin Peng Shuqing Zhou Tayirjan Taylor Isimjan Xiulin yang Guangxi Key Laboratory of Low Carbon Energy Materials School of Chemistry and Pharmaceutical SciencesGuangxi Normal UniversityGuilin 541004China Saudi Arabia Basic Industries Corporation(SABIC)at King Abdullah University of Science and Technology(KAUST) Thuwal 23955-6900Saudi Arabia

Application of transition metal boride(TMB) catalysts towards hydrolysis of NaBH_(4) holds great significance to help relieve the energy crisis. Herein, we present a facile and versatile metal-organic framework(MOF) assisted strategy to prepare Co_(2)B-CoPO_x with massive boron vacancies by introducing phytic acid(PA) cross-linked Co complexes that are acquired from reaction of PA and ZIF-67 into cobalt boride. The PA etching effectively breaks down the structure of ZIF-67 to create more vacancies, favoring the maximal exposure of active sites and elevation of catalytic activity. Experimental results demonstrate a drastic electronic interaction between Co and the dopant phosphorous(P), thereby the robustly electronegative P induces electron redistribution around the metal species, which facilitates the dissociation of B-H bond and the adsorption of H_(2)O molecules. The vacancy-rich Co_(2)B-CoPO_x catalyst exhibits scalable performance, characterized by a high hydrogen generation rate(HGr) of 7716.7 m L min^(-1)g^(-1) and a low activation energy(Ea) of 44.9 k j/mol, rivaling state-of-the-art catalysts. This work provides valuable insights for the development of advanced catalysts through P doping and boron vacancy engineering and the design of efficient and sustainable energy conversion systems.

关键词： Co_(2)B-CoPO_x catalyst P doping Boron vacancy NaBH_(4) hydrolysis Hydrogen generation

Analysis of mid-spatial frequency wavefront distortions from a liquid-cooled flash-lamp pumped Nd:phosphate laser amplifier

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High Power Laser Science and Engineering 2024年第1期12卷 24-29页

作者： Pierre-Marie Dalbies Sandy Cavaro Edouard Bordenave Nathalie Blanchot julien G.Moreau jérôme Neauport CEA CESTA Le BarpFrance

Mid-spatial frequency wavefront deformation can be deleterious for the operation of high-energy laser systems. When fluid cooled high-repetition-rate amplifiers are used, the coolant flow is likely to induce such detrimental mid-spatial frequency wavefront deformations. Here, we describe the design and performance of a 90 mm × 90 mm aperture, liquid-cooled Nd:phosphate split-slab laser amplifier pumped by flash-lamps. The performance of the system is evaluated in terms of wavefront aberration and gain at repetition rates down to 1 shot per minute. The results show that this single cooled split-slab system exhibits low wavefront distortions in the medium to large period range, compatible with a focus on target, and despite the use of liquid coolant traversed by both pump and amplified wavelengths. This makes it a potential candidate for applications in large high-energy laser facilities.

关键词： flash-lamp pumping high-power laser laser cooling neodymium glass wavefront error

Error field penetration in j-TEXT tokamak based on two-fluid drift-MHD model

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Chinese Physics B 2024年第4期33卷 545-551页

作者：王文徐涛张仪 the j-TEXT team State Key Laboratory of Advanced Electromagnetic Technology International Joint Research Laboratory of Magnetic Confinement Fusion and Plasma PhysicsSchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074China

An externally generated resonant magnetic perturbation can induce complex non-ideal MHD responses in their resonant *** have studied the plasma responses using Fitzpatrick's improved two-fluid model and program *** calculated the error field penetration threshold for *** addition,we find that the island width increases slightly as the error field amplitude increases when the error field amplitude is below the critical penetration ***,the island width suddenly jumps to a large value because the shielding effect of the plasma against the error field disappears after the *** scanning the natural mode frequency,we find that the shielding effect of the plasma decreases as the natural mode frequency ***,we obtain the m/n=2/1 penetration threshold scaling on density and temperature.

关键词： plasma responses drift-MHD model error field penetration