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Identification and Characteristics Analysis of Micro-Seismic Signals in the Haima Seep Area

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Journal of Earth Science 2024年第1期35卷 288-291页

作者： Xiangchun Wang bing nie Zhiyu Wu Weiwei Wang Hua Chen China University of Geosciences Beijing 100083China CNOOC China Limited Shenzhen BranchShenzhen 518000China Guangzhou Marine Geological Survey Guangzhou 511458China CNOOC China Limited Shanghai BranchShanghai 200335China

*** recent years,with the steady development of offshore energy exploration technology,submarine gas seepage sites,and their products are gradually being identified and *** submarine cold seep is a seepage phenomenon in which hydrocarbon gases stored deep in the seafloor are transported to seawater by gushing or seepage under the action of tectonic compression(Roy et al.,2019;Tinivella and Giustiniani,2016).

关键词： submarine Seismic offshore

Simulation and evaluation study of atmospheric aerosol nonsphericity as a function of particle size

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Particuology 2024年第7期90卷 281-291页

作者： Qianjun Mao Xin nie School of Urban Construction Wuhan University of Science and TechnologyWuhan430065China College of New Energy and Materials Northeast Petroleum UniversityDaqing163318China

Aerosol nonsphericity causes great uncertainty in radiative forcing assessments and climate *** considerable studies have attempted to quantify this uncertainty,the relationship between aerosol nonsphericity and particle size is usually not considered,thus reducing the accuracy of the *** this study,a coupled inversion algorithm combining an improved stochastic particle swarm optimization algorithm and angular light scattering is used for the nonparametric estimation of aerosol nonsphericity variation with particle size,and the optimal sample selection method is employed to screen the *** on the verification of inversion accuracy,the variation of aerosol aspect ratio with particle size based on the ellipsoidal model in global regions has been obtained from Aerosol Robotic Network(AERONET)data,and the effect of nonsphericity on radiative forcing and dry deposition has been *** results show that the aspect ratio increases with particle size in all regions,with the maximum ranging from 1.4 to 1.8 in the desert,reflecting the differences in aerosol composition at different particle *** radiation calculations,considering aerosol nonsphericity makes the aerosol cooling effect weaker and surface radiative fluxes increase,but hardly changes the aerosol absorption,with maximum differences of 9.22%and 22.12%at the bottom and top of the atmosphere,***,the differences in radiative forcing between aspect ratios as a function of particle size and not varying with particle size are not significant,averaging less than 2%.Besides,the aspect ratio not varying with particle size underestimates the deposition velocity of small particles and overestimates that of large particles compared to that as a function of particle size,with maximum differences of 7%and 4%,respectively.

关键词： Aerosol nonsphericity Inversion Aspect ratio Radiative forcing Dry deposition velocity

Comprehensive insights:unraveling the mechanisms of gut commensals in glucose metabolism regulation

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Science China(Life Sciences) 2024年第2期67卷 414-417页

作者： Zhipeng Li Qixing nie Shao-Ping nie State Key Laboratory of Food Science and Resources China-Canada Joint Lab of Food Science and Technology(Nanchang)Key Laboratory of Bioactive Polysaccharides of Jiangxi ProvinceNanchang UniversityNanchang 330047China

The prevalence of type 2 diabetes(T2D)has escalated to a global epidemic,garnering widespread *** research utilizing germ-free(GF)mice,antibiotic treatments,and fecal microbiota transplantation approaches has established the critical role of gut microbiota in modulating glucose *** microbiota interacts with diets and the mucosal immune system,influencing intestinal permeability and the penetration of microbial products.

关键词： metabolism utilizing insight

Atomically Precise Design of PtSn Catalyst for the Understanding of the Role of Sn in Propane Dehydrogenation

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Precision Chemistry 2024年第6期2卷 245-255页

作者： Hui Ye Lina Cao Minghui Gu Han nie Qingqing Gu bing Yang Yunxing Bai Qinxue nie Weixin Huang Junling Lu Institute of Advanced Technology Key Laboratory of Precision and Intelligent ChemistryDepartment of Chemical PhysicsHefei National Research Center for Physical Sciences at the MicroscaleKey Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education InstitutesUniversity of Science and Technology of ChinaHefei 230026P.R.China CAS Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical PhysicsThe Chinese Academy of SciencesDalian 116023P.R.China

Propane dehydrogenation(PDH),an atom-economic reaction to produce high-value-added propylene and hydrogen with high efficiency,has recently attracted extensive *** severe deactivation of Pt-based catalysts through sintering and coking remains a major challenge in this high-temperature *** introduction of Sn as a promoter has been widely applied to improve the stability and selectivity of the ***,the selectivity and stability of PtSn catalysts have been found to vary considerably with synthesis methods,and the role of Sn is still far from fully *** gain in-depth insights into this issue,we synthesized a series of PtSn/SiO_(2)and SnPt/SiO_(2)catalysts by varying the deposition sequence and Pt:Sn ratios using atomic layer deposition with precise *** found that PtSn/SiO_(2)catalysts fabricated by the deposition of SnO_(x)first and then Pt,exhibited much better propylene selectivity and stability than the SnPt/SiO_(2)catalysts synthesized the other way *** demonstrate that the presence of Sn species at the Pt-SiO_(2)interface is of essential importance for not only the stabilization of PtSn clusters against sintering under reaction conditions but also the promotion of charge transfers to Pt for high *** the above,the precise regulation of the Sn content is also pivotal for high performance,and the excess amount of Sn might generate additional acidic sites,which could decrease the propylene selectivity and lead to heavy coke *** findings provide deep insight into the design of highly selective and stable PDH catalysts.

关键词： Propane dehydrogenation PtSn catalysts sintering coke formation acidity

Recent advances in high charge density triboelectric nanogenerators

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International Journal of Extreme Manufacturing 2024年第4期6卷 1-19页

作者： Xin Cui Jiaheng nie Yan Zhang School of Physics University of Electronic Science and Technology of ChinaChengdu 611731People's Republic of China School of Cybersecurity Chengdu University of Information TechnologyChengdu 610225People's Republic of China Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 100083People's Republic of China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049People's Republic of China

Triboelectric materials with high charge density are the building-block for the commercial application of triboelectric nanogenerators(TENGs).Unstable dynamic processes influence the change of the charge density on the surface and inside of triboelectric *** charge density of triboelectric materials depends on the surface and the internal charge transfer *** focus of this review is on recent advances in high charge density triboelectric materials and advances in the fabrication of *** summarize the existing strategies for achieving high charge density in triboelectric materials as well as their fundamental *** then review current optimization methods for regulating dynamic charge transfer processes to increase the output charge density:first,increasing charge injection and limiting charge dissipation to achieve a high average surface charge density,and second,regulating the internal charge transfer process and storing charge in triboelectric materials to increase the output charge ***,we present the challenges and prospects in developing high-performance triboelectric materials.

关键词： triboelectric nanogenerator charge density charge transfer charge store

Recent advances in small-scale hydrogel-based robots for adaptive biomedical applications

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Nano Research 2024年第2期17卷 649-662页

作者： Mingzhe nie Qilong Zhao Xuemin Du Institute of Biomedical&Health Engineering Shenzhen Institute of Advanced Technology(SIAT)Chinese Academy of Sciences(CAS)Shenzhen 518055China

Small-scale robots,ranging in size from micrometers to centimeters,have gained significant attention in the biomedical ***,conventional small-scale robots made of rigid materials encounter challenges in adapting themselves to the soft tissues and complicated environments of human *** to the rigid counterpart,small-scale hydrogel-based robots hold great promises due to their tissue-like low modulus,outstanding biocompatibility and accessible stimuli-responsive *** attributes offer small-scale hydrogel-based robots with multimodal locomotion and reinforced functions,further enhancing the adaptability in manipulation and tasks execution for various biomedical *** this review,we present recent advances in small-scale hydrogel-based *** first summarize the design principles of small-scale hydrogel-based robots including materials,fabrication techniques and manipulation strategies,then highlighting their upgraded functions and adaptive biomedical ***,we discuss existing challenges and future perspectives for small-scale hydrogel-based robots.

关键词： small-scale robot hydrogel locomotion multi-function adaptability

Collectively induced transparency and absorption in waveguide quantum electrodynamics with Bragg atom arrays

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Communications in Theoretical Physics 2024年第8期76卷 19-28页

作者： Haolei Cheng Wei nie Center for Joint Quantum Studies and Department of Physics School of ScienceTianjin UniversityTianjin 300350China Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology Tianjin UniversityTianjin 300350China

Collective quantum states, such as subradiant and superradiant states, are useful for controlling optical responses in many-body quantum systems. In this work, we study novel collective quantum phenomena in waveguide-coupled Bragg atom arrays with inhomogeneous *** atoms without free-space dissipation, collectively induced transparency is produced by destructive quantum interference between subradiant and superradiant states. In a large Bragg atom array, multi-frequency photon transparency can be obtained by considering atoms with different frequencies. Interestingly, we find collectively induced absorption(CIA) by studying the influence of free-space dissipation on photon transport. Tunable atomic frequencies nontrivially modify decay rates of subradiant states. When the decay rate of a subradiant state equals to the free-space dissipation, photon absorption can reach a limit at a certain frequency. In other words, photon absorption is enhanced with low free-space dissipation, distinct from previous photon detection schemes. We also show multi-frequency CIA by properly adjusting atomic frequencies. Our work presents a way to manipulate collective quantum states and exotic optical properties in waveguide quantum electrodynamics(QED) systems.

关键词： waveguide quantum electrodynamics collective quantum states photon absorption Bragg atom array

Matched Volterra reduced-order model for an airfoil undergoing periodic translation

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Chinese Journal of Aeronautics 2024年第1期37卷 19-23页

作者： Lianrui nie Ziniu WU Department of Engineering Mechanics Tsinghua UniversityBeijing 100084China

This paper is devoted to application of the Reduced-Order Model(ROM)based on Volterra series to prediction of lift and drag forces due to airfoil periodic translation in transonic flow *** there is large amplitude oscillation of the relative Mach number,as appeared in helicopter rotor movement in forward flight,the conventional Volterra ROM is found to be *** cover such applications,a matched Volterra ROM,inspired from previous multistep nonlinear indicial response method based on Duhamel integration,is thus considered,in which the step motions are defined inside a number of equal intervals with both positive and negative step motions to match the airfoil forward and backward movement,and the kernel functions are constructed independently at each *** shows that,at least for the translation movement considered,this matched Volterra ROM greatly improves the accuracy of ***,the matched Volterra ROM,with the total number of step motions and thus the computational cost close to those of the conventional Volterra ROM method,has the additional advantage that the same set of kernels can match various translation motions with different starting conditions so the kernels can be predesigned without knowing the specific motion of airfoil.

关键词： Airfoil periodic translation Lift and drag Reduced-order model Transonic flow Unsteady flow

A variable structure passivity control method for elastic joint robots based on cascaded high-order state estimation

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Science China(Technological Sciences) 2024年第2期67卷 395-407页

作者： ZHANG JieXin nie PingYun ZHANG Bo State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240China

Passivity-based controllers are widely used to facilitate physical interaction between humans and elastic joint robots,as they enhance the stability of the interaction ***,the joint position tracking performance can be limited by the structures of these controllers when the system is faced with uncertainties and rough high-order system state measurements(such as joint accelerations and jerks).This study presents a variable structure passivity(VSP)control method for joint position tracking of elastic joint robots,which combines the advantages of passive control and variable structure *** method ensures the tracking error converges in a finite time,even when the system faces *** method also preserves the passivity of the ***,a cascaded observer,called CHOSSO,is also proposed to accurately estimate high-order system states,relying only on position and velocity *** observer allows independent implementation of disturbance compensation in the acceleration and jerk estimation *** particular,the observer has an enhanced ability to handle fast time-varying disturbances in physical human-robot *** effectiveness of the proposed method is verified through simulations and experiments on a lower limb rehabilitation robot equipped with elastic joints.

关键词： motion control elastic joint robot finite-time convergence high-order system state estimation physical human-robot interaction