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Unraveling the Cenozoic carbon cycle by reconstructing carbonate compensation depth(CCD)

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Science China Earth Sciences 2024年第6期67卷 1743-1758页

作者： Kaixun xiao Xiumian hu Jingxin JIANG Jiahao WANG State Key Laboratory of Mineral Deposit Research School of Earth Sciences and EngineeringNanjing UniversityNanjing 210023China

The Carbonate Compensation Depth(CCD)refers to the depth within the ocean where the production and dissolution rates of carbonates reach equilibrium,widely likened to the oceanic calcareous‘snowline’.The reconstruction of deep-time CCD has significant implications for understanding ocean circulation,seawater chemical conditions,sediment distribution,and the surface carbon *** paper critically reviews the methods for CCD reconstruction,summarizes the driving mechanisms of the Cenozoic CCD evolution and its association with the carbon cycle,and offers insights into future directions for CCD *** reconstruction has evolved over the past half century from early qualitative to quantitative *** methodological improvements have markedly improved the accuracy and resolution of *** studies have indicated a general trend of the CCD deepening across major ocean basins since the Cenozoic,interspersed with a minor shallowing phase during the *** variations in the CCD are primarily influenced by factors such as ocean productivity,weathering,and shelf-basin *** climate events such as the Paleocene-Eocene Thermal Maximum,the CCD exhibits pulselike *** research should focus on precision and quantification while integrating model simulations to further explore the correlations and response mechanisms between the CCD and the paleoclimate as well as the carbon cycle.

关键词： Carbonate Compensation Depth Cenozoic Carbon cycle Paleoclimate Paleoceanography

Quantitative Analysis of Seeing with Height and Time at Muztagh-Ata Site Based on ERA5 Database

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Research in Astronomy and Astrophysics 2024年第1期24卷 87-95页

作者： xiao-qi Wu Cun-Ying xiao Ali Esamdin Jing Xu Ze-Wei Wang Luo xiao Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Department of Astronomy Beijing Normal UniversityBeijing 100875China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China

Seeing is an important index to evaluate the quality of an astronomical *** estimate seeing at the Muztagh-Ata site with height and time quantitatively,the European Centre for Medium-Range Weather Forecasts reanalysis database(ERA5)is *** calculated from ERA5 is compared consistently with the Differential Image Motion Monitor seeing at the height of 12 *** show that seeing decays exponentially with height at the Muztagh-Ata *** decays the fastest in fall in 2021 and most slowly with height in *** seeing condition is better in fall than in *** median value of seeing at 12 m is 0.89 arcsec,the maximum value is1.21 arcsec in August and the minimum is 0.66 arcsec in *** median value of seeing at 12 m is 0.72arcsec in the nighttime and 1.08 arcsec in the *** is a combination of annual and about biannual variations with the same phase as temperature and wind speed indicating that seeing variation with time is influenced by temperature and wind *** Richardson number Ri is used to analyze the atmospheric stability and the variations of seeing are consistent with Ri between *** quantitative results can provide an important reference for a telescopic observation strategy.

关键词： site testing atmospheric effects methods:data analysis telescopes Earth

Recyclable Polypropylene-based Insulation Materials for HVDC Cables:Progress and Perspective

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CSEE Journal of Power and Energy Systems 2024年第5期10卷 2208-2220页

作者： Yao Zhou Shixun hu Chao Yuan Jun hu qi Li Jinliang He State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China Beijing Key Lab of High Voltage&EMC and State Key Lab of Alternate Electrical Power System with Renewable Energy SourcesNorth China Electric Power UniversityBeijing 102206China.

Polypropylene(PP)-based recyclable materials have attracted tremendous interest for HVDC cable insulation applications due to their superior electrical properties,e.g.,high thermal stability and superior *** with crosslinked polyethylene(XLPE),PP-based materials exhibit the advantages of not only higher working temperatures but also facile and efficient cable manufacturing with reduced costs,which are highly desirable in HVDC cable *** their promising advantages,PP-based materials have received significant attention from both academia and industry in the field of HVDC cable *** order to adopt PP as a cable insulation material,the mechanical flexibility of PP should be ***,regulations of the mechanical properties inevitably influences the electrical properties of *** extensive research has been conducted on the regulation of the mechanical and electrical properties of *** review summarizes the research progress on recyclable PP-based materials for HVDC cable insulation *** attention is placed on the electrical property regulations and material structure-property *** challenges that remain to be addressed and the opportunities for future studies on PP-based recyclable HVDC cable insulation materials are also presented.

关键词： polypropylene HVDC cable dielectric materials recyclable insulation materials

Stabilizing perovskite precursors with the reductive natural amino acid for printable mesoscopic perovskite solar cells

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Journal of Energy Chemistry 2024年第3期90卷 32-39,I0003页

作者： Wenjing hu Jian Yang Chuang Yang Xufeng xiao Chaoyang Wang Zhaozhen Cui qiaojiao Gao Jianhang qi Minghao Xia Yaqiong Su Anyi Mei Hongwei Han Michael Gratzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for OptoelectronicsKey Laboratory of Materials Chemistry for Energy Conversion and Storage of Ministry of Education Huazhong University of Science and TechnologyWuhan 430074HubeiChina School of Chemistry Xi'an Key Laboratory of Sustainable Energy Materials ChemistryState Key Laboratory of Electrical Insulation and Power EquipmentXi'an Jiaotong UniversityXi'an 710049ShaanxiChina

Solution processability significantly advances the development of highly-efficient perovskite solar ***,the precursor solution tends to undergo irreversible degradation reactions,impairing the device performance and ***,we utilize a reductive natural amino acid,Nacetylcysteine(NALC),to stabilize the precursor solution for printable carbon-based hole-conductorfree mesoscopic perovskite solar *** find that I_(2) can be generated in the aged solution containing methylammonium iodide(MI) in an inert atmosphere and speed up the MA-FA^(+)(formamidinium) reaction which produces large-size cations and hinders the formation of perovskite *** effectively stabilizes the precursor via its sulfhydryl group which reduces I_(2) back to I^(-)and provides H^(+).The NALC-stabilized precursor which is aged for 1440 h leads to devices with a power conversion efficiency equivalent to 98% of that for devices prepared with the fresh ***,NALC improves the device power conversion efficiency from 16.16% to 18.41% along with enhanced stability under atmospheric conditions by modifying grain boundaries in perovskite films and reducing associated defects.

关键词： Perovskite solar cells Perovskite precursor Degradation Stabilization Reductive natural amino acid

Enhanced cycling stability and rate performance of Co-doped and La_(2)O_(3)-coated LiNi_(0.9)Mn_(0.1)O_(2) toward power battery

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Rare Metals 2024年第2期43卷 658-670页

作者： Jia-qi Peng Yuan-Yuan Wei Dong-Ming Liu Yun Li Bin hu Bin huang Jian-Wen Yang Shun-hua xiao Ren-Heng Wang Guangxi Key Laboratory of Electrochemical and Magneto-Chemical Functional Materials College of Chemistry and BioengineeringGuilin University of TechnologyGuilin541004China Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province College of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China

Ultra-high nickel layered oxide cathode material with high energy density is the most promising material to improve the electrochemical performance of lithium-ion batteries(LIBs).However,the poor structural stability and severe surface/interface side reactions of the material lead to poor rate performance and cyclic stability,which limits its application in *** this paper,the dual-modification strategy of Co doping and La_(2)O_(3) coating is used to meet the above *** doping can effectively widen layer spacing and reduce Li^(+)/Ni^(2+) mixing,and La_(2)O_(3) coating can effectively eliminate the residual alkali on the surface of active material,inhibit the thickening of cathode electrolyte interphase(CEI)film and reduce surface/interface side ***,the modified material(NM90-CL)with excellent electrochemical properties is achieved through the synergistic enhancement of Co doping and La_(2)O_(3) *** capacity retention rate can reach 77.9%after 200 cycles at 1.0℃ and 75.7%after 200 cycles at 5.0℃.Its reversible capacity can up to 153.5 mAh·g^(–1) at 10.0℃.This dual-modification strategy will provide theoretical guidance and technical support for the synthesis of other high-performance electrode materials.

关键词： High nickel cathode material Co doping La_(2)O_(3) coating Electrochemical performance Electrochemical mechanism

Ordered Bicontinuous Network Structures Regulated by Orientational Interactions in a Rod-Coil Block Copolymer

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Chinese Journal of Polymer Science 2024年第5期42卷 636-642,I0008页

作者： xiao-Lin Lyu Shi-Chu Yang An-qi xiao Ping-Ping Hou Wei Zhang Hong-Bing Pan Zhi-Hao Shen Xing-He Fan qi-Feng Zhou Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China Key Laboratory of Advanced Materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesCollege of Materials Science and EngineeringFuzhou UniversityFuzhou350108China

The rich phase behavior of block copolymers(BCPs)has drawn great attention in recent ***,the double diamond(DD)phase is rarely obtained because of the competition between the minimization of interfacial energy and packing ***,a rod-coil BCP containing mesogen-jacketed liquid crystalline polymer is designed to acquire ordered bicontinuous network *** reduction of internal energy originating from the orientational interaction among the rod blocks can compensate for the free energy penalty of packing frustration to stabilize the DD *** resulting BCP can also experience lamellae-to-DD and double gyroid-to-lamellae transitions by changing the annealing *** results make the rod-coil BCP an excellent candidate for the self-assembly of ordered network structures,demonstrating great potential in nanopatterning and metamaterials.

关键词： Block copolymer Rod-coil Ordered bicontinuous phase Double diamond Double gyroid

Research,application and development of inorganic binder for casting process

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China Foundry 2024年第5期21卷 461-475页

作者： xiao-long Gong Sheng-li hu Zi-tian Fan State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

Inorganic binder used in casting process has the advantages of low odor,labor-friendly conditions,and relatively low cost,which is one of the main development directions for casting molding materials in the ***,compared to organic binders(such as resin binders),inorganic binders exhibit lower bonding strength and are more sensitive to environmental *** sensitivity poses challenges,particularly in the reclamation of used sand,thus limiting their broader *** this paper,the research and application status of inorganic binders(mainly silicate inorganic binders)and their curing methods are *** addition,the research and application of phosphate inorganic binders and 3D printing inorganic binders that are being developed are ***,a detailed comparative analysis is conducted on the challenging issue of“reclamation for used sand”in the application of inorganic ***,the development direction of inorganic binders is clarified.

关键词： inorganic binder silicate system phosphate system 3D printing used sand reclamation development trend

Design of a Bio-inspired,Two-winged,Flapping-wing Micro Air Vehicle with High-lift Performance

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Journal of Bionic Engineering 2024年第3期21卷 1191-1207页

作者： Kai hu huichao Deng Shengjie xiao Gongyu Yang Yuhong Sun Space Robot Laboratory The School of Mechanical EngineeringBeihang UniversityBeijing100191China

In this paper,we present the development of our latest flapping-wing micro air vehicle(FW-MAV),named Explobird,which features two wings with a wingspan of 195 mm and weighs a mere 25.2 g,enabling it to accomplish vertical take-off and hover *** devised a novel gear-based mechanism for the flapping system to achieve high lift capability and reliability and conducted extensive testing and analysis on the wings to optimise power matching and lift *** Explobird can deliver a peak lift-to-weight ratio of 1.472 and an endurance time of 259 s during hover flight powered by a single-cell LiPo *** the inherent instability of the prototype,we discuss the derivatives of its longitudinal system,underscoring the importance of feedback control,position of the centre of gravity,and increased *** demonstrate the effect of damping enhancement on stability,we also designed a passive stable ***,the vehicle is actively stabilised in roll by adjusting the wing root bars and in pitch through high-authority tail control,whereas yaw is passively *** a series of flight tests,we successfully demonstrate that our prototype can perform vertical take-off and hover flight under wireless *** promising results position the Explobird as a robust vehicle with high lift capability,paving the way towards the use of FW-MAVs for carrying load equipment in multiple tasks.

关键词： Flapping wing Biologically inspired robots Mechanical design Flight dynamics Damping enhancement

Modular Soft Robotic Crawlers Based on Fluidic Prestressed Composite Actuators

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Journal of Bionic Engineering 2024年第2期21卷 694-706页

作者： Zefeng Xu Linkai hu Longya xiao Hongjie Jiang Yitong Zhou Shien-Ming Wu School of Intelligent Engineering South China University of TechnologyGuangzhou511442China School of Mechanical and Electrical Engineering Guangzhou UniversityGuangzhou510006China

Soft robotic crawlers have limited payload capacity and crawling *** study proposes a high-performance inchworm-like modular robotic crawler based on fluidic prestressed composite(FPC)*** FPC actuator is precurved and a pneumatic source is used to flatten it,requiring no energy cost to maintain the equilibrium curved *** and depressurizing the actuators generate alternating stretching and bending motions of the actuators,achieving the crawling motion of the robotic ***-modal locomotion(crawling,turning,and pipe climbing)is achieved by modular reconfiguration and gait *** analytical kinematic model is proposed to characterize the quasi-static curvature and step size of a single-module *** configurations of robotic crawlers are fabricated to demonstrate the crawling ability of the proposed design.A set of systematic experiments are set up and conducted to understand how crawler responses vary as a function of FPC prestrains,input pressures,and actuation *** per the experiments,the maximum carrying load ratio(carrying load divided by robot weight)is found to be 22.32,and the highest crawling velocity is 3.02 body length(BL)per second(392 mm/s).Multi-modal capabilities are demonstrated by reconfiguring three soft crawlers,including a matrix crawler robot crawling in amphibious environments,and an inching crawler turning at an angular velocity of 2/s,as well as earthworm-like crawling robots climbing a 20 inclination slope and pipe.

关键词： Soft robot Soft crawler Fluidic prestressed composite Kinematic model Enhanced loading Multi-modal capability