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Bandgap characteristics analysis and graded design of a novel metamaterial for flexural wave suppression

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applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 1-24页

作者： Fan YANG Zhaoyang MA Xingming GUO Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai University Shanghai institute of Aircraft Mechanics and Control

A novel elastic metamaterial is proposed with the aim of achieving lowfrequency broad bandgaps and bandgap regulation. The band structure of the proposed metamaterial is calculated based on the Floquet-Bloch theorem, and the boundary modes of each bandgap are analyzed to understand the effects of each component of the unit cell on the bandgap formation. It is found that the metamaterials with a low elastic modulus of ligaments can generate flexural wave bandgaps below 300 Hz. Multi-frequency vibrations can be suppressed through the selective manipulation of bandgaps. The dual-graded design of metamaterials that can significantly improve the bandgap width is proposed based on parametric studies. A new way that can regulate the bandgap is revealed by studying the graded elastic modulus in the substrate. The results demonstrate that the nonlinear gradient of the elastic modulus in the substrate offers better bandgap performance. Based on these analyses, the proposed elastic metamaterials can pave the way for multi-frequency vibration control, low-frequency bandgap broadening, and bandgap tuning.

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Multi boron-doping effects in hard carbon toward enhanced sodium ion storage

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Journal of Energy Chemistry 2025年第1期100卷 730-738页

作者： Peng Zheng Wang Zhou Ying Mo Biao Zheng Miaomiao Han Qin Zhong Wenwen Yang Peng Gao Lezhi Yang Jilei Liu College of Materials Science and Engineering Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology Hunan University Greater Bay Area institute for Innovation Hunan University Changsha Research institute of Mining & Metallurgy Co. LTD.

Hard carbon （HC） has been considered as promising anode material for sodium-ion batteries （SIBs）.The optimization of hard carbon’s microstructure and solid electrolyte interface （SEI） property are demonstrated effective in enhancing the Na+storage capability,however,a one-step regulation strategy to achieve simultaneous multi-scale structures optimization is highly ***,we have systematically investigated the effects of boron doping on hard carbon’s microstructure and interface chemistry.A variety of structure characterizations show that appropriate amount of boron doping can increase the size of closed pores via rearrangement of carbon layers with improved graphitization degree,which provides more Na+storage ***-situ Fourier transform infrared spectroscopy/electrochemical impedance spectroscopy （FTIR/EIS） and X-ray photoelectron spectroscopy （XPS） analysis demonstrate the presence of more BC3and less B–C–O structures that result in enhanced ion diffusion kinetics and the formation of inorganic rich and robust SEI,which leads to facilitated charge transfer and excellent rate *** a result,the hard carbon anode with optimized boron doping content exhibits enhanced rate and cycling *** general,this work unravels the critical role of boron doping in optimizing the pore structure,interface chemistry and diffusion kinetics of hard carbon,which enables rational design of sodium-ion battery anode with enhanced Na+storage performance.

关键词： X ray photoelectron spectroscopy

Efficient and simple synthesis of B_(2)O_(3)-Al_(2)O_(3)nanocomposites assisted by deep eutectic solvent for production of 5-hydroxymethylfurfural from glucose

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Nano Research 2025年第1期18卷 236-248页

作者： Yuchen Wang Kai Rong Shanlei Chang Youxing Fang Shaojun Dong State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China College of Chemistry Jilin UniversityChangchun 130012China

The catalytic conversion of glucose to high valueadded platform chemical 5-hydroxymethylfurfural(HMF)is a promising biorefinery process,and alumina-boria catalysts are considered to be green and mild solid acid catalysts for this catalytic ***,compared to the common synthesis methods with complicated steps,we reported a simple and efficient strategy to prepare B_(2)O_(3)-Al_(2)O_(3)nanocomposites by calcining cost-effective glucose-urea deep eutectic solvent(DES)solution containing the *** prepared B_(2)O_(3)-Al_(2)O_(3)nanocomposites exhibited an open three-dimensional skeleton and two-dimensional porous lamellar substructure,endowing them with a high specific surface area(228.27 m2/g).The introduction of boron changed the ratios of different aluminum species(AlⅣ,AlⅤ,and AlⅥ)and borate species(BO3 and BO4),thus further affecting the acidity and the types of acid sites of the *** prepared B_(2)O_(3)-Al_(2)O_(3)bifunctional acid catalysts possessing abundant Lewis acid sites and adjustable Brønsted acid sites showed complete glucose conversion and 55.38%of HMF yield under the optimum *** study proposed a concise method to synthesize alumina-boria solid acid catalysts assisted by glucose-urea *** hope to extend the application and prospect of this efficient and simple synthesis strategy.

关键词： 5-hydroxymethylfurfural(HMF) deep eutectic solvent glucose alumina-boria acid catalyst

Endogenous/exogenous dual stimulation“ROS engineering”amplification combined with autophagy-augmented for efficient ferroptosis therapy

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Nano Research 2025年第1期18卷 597-606页

作者： Pengye Du Pengpeng Lei Yuan Liang Ran An Yi Wei Shuyu Liu Jianhao Zheng Hongjie Zhang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China Department of Chemistry Tsinghua UniversityBeijing 100084China

“Reactive oxygen species(ROS)engineering”is one of the most promising anti-tumor treatments developed in recent *** explosion of ROS will cause oxidative stress,thereby inducing tumor cell ***,ROS accumulation in tumor cells is eliminated by endogenous cellular self-regulation *** this work,a kind of endogenous/exogenous dual stimulation nanoagent noted as UMZC is *** reaction occurs between NH_(2)-MIL-88B(Fe)contained in UMZC and the overexpression of endogenous H_(2)O_(2)to generate ROS,amplified by endogenous H_(2)S of colon tumor *** addition,NH_(2)-MIL-88B(Fe)also functions to deplete glutathione(GSH)for stopping it from consuming *** nanoparticles at the core of UMZC convert near-infrared into visible light,which excites zinc phthalocyanine to initiate the photochemical reaction that generates more ROS,thus alleviating the lack of tissue penetration depth for visible *** agonist chitosan oligosaccharides induce enhancement of cellular autophagy for disrupting cellular metabolic stress and the resistance to oxidative stress of tumor cells,allowing“ROS engineering”to fully exert anti-tumor *** of ROS generation,GSH depletion,and induced cellular autophagy caused by nanoagents have promoting effects on the occurrence of ***,the nanoagents show the ability to effectively treat colon tumors.

关键词： reactive oxygen species(ROS)engineering upconversion nanoparticles cellular autophagy ferroptosis tumor therapy

Targets capture by distributed active swarms via bio-inspired reinforcement learning

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 210-221页

作者： Kun Xu Yue Li Jun Sun Shuyuan Du Xinpeng Di Yuguang Yang Bo Li institute of Biomechanics and Medical Engineering Applied Mechanics Laboratory Department of Engineering MechanicsTsinghua University institute of Nuclear and New Energy Technology Tsinghua University Shanghai Aerospace Control Technology institute Shanghai Key Laboratory of Aerospace Intelligent Control Technology College of Automation Engineering Nanjing University of Aeronautics and Astronautics

Natural swarms arranged from cells to herds are usually decentralized but display intriguing collective intelligence in coordinating individuals across large scales to efficiently achieve their common goals. Learning from nature may provide new strategies for controlling collective dynamics of synthetic swarms to accomplish specific functions. Here, we present a bioinspired computational framework that steers distributed active swarms to collectively capture and merge targets via reinforcement learning. We exploit collective milling structures of natural herds to cage the targets, and adopt a switching control policy inspired by sperms' chiral dynamics to optimize the trajectories of individuals, through which the active swarms can selforganize to enclose single or multiple distant targets in a dynamical, adaptive and scalable manner. There exists a critical swarm size, beyond which the excessive competition between agents would generate large mechanical forces, leading to capture instability but enabling the transition from short-distance to long-distance merging capture of multiple targets. This work provides physical insights into distributed active swarms and could offer a multilevel, decentralized strategy toward controlling swarm robotics in wide applications such as bio-medical devices, machine immunity, and target clearance.

关键词： swarm intelligence robotics multi-tasks artificial intelligence bionics

Carbon-supported CeNCl as an efficient catalyst for CO_(2)cycloaddition

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Nano Research 2025年第1期18卷 157-163页

作者： Li Liu Lingling Zhang Xiang Chu Baokang Geng Huilin Wang Zongxiang Li Xiao Wang Shuyan Song Hongjie Zhang School of applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Sinocare Incorporation Changsha 410221China Department of Chemistry Tsinghua UniversityBeijing 100084China

The cycloaddition reaction of CO_(2)with epoxide not only effectively reduces the concentration of CO_(2)in the atmosphere,but also has excellent industrial application value and up to 100%atom utilization,but there are difficulties in separation and recovery of traditional homogeneous catalysts,harsh reaction conditions of traditional heterogeneous catalysts,and activation of CO_(2)*** this paper,an easily synthesized heterogeneous catalyst CeNCl/C was used to catalyze the cycloaddition reaction of CO_(2)with styrene oxide,with a high yield of 92.7%,a high selectivity of 96.7%,a turnover numbers(TON)value of 349,and a good stability demonstrated in six cycle tests(equivalent to 216 h of testing).Through comprehensive studies,it was shown that CeNCl/C contains Lewis acid-base centers as active centers,which can effectively reduce the energy barrier required for ring opening of the reaction substrate,enhance the adsorption and activation of CO_(2),and promote the formation of intermediates,which led to the acquisition of excellent catalytic activity.

关键词： CO_(2)cycloaddition heterogeneous catalysis CeNCl Lewis acid/base

Excitation patterns and phonetic identities of Chinese vowels

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Science in China(Series F) 2009年第10期52卷 1936-1946页

作者： YU ShuiYuan institute of applied linguistics Communication University of China Beijing 100024 China

After entering the peripheral auditory system, a sound undergoes many significant changes. The excitation pattern describes these changes psychoacoustically as inner expression. This study investigates the relations between excitation patterns and their phonetic qualities for Chinese steady-state vowels. First, the peak positions of the envelope of excitation patterns were measured on a database. The results demonstrated that each Chinese vowel has its own special position for the representative peak of the excitation pattern. Second, to examine the sufficiency of these results, a series of experiments that consisted of identification and evaluation tasks were conducted, in which spectral components of natural isolated vowels were manipulated to create certain excitation patterns. Subjects＇ responses of these stimuli show that the position of the representative peak of the excitation pattern of a vowel plays a crucial role on its phonetic identity. The results suggest that the phonetic identity of vowels is determined by the position of the representative peak of the excitation pattern evoked by it, and other peaks, if any, do not have phonetic meaning. Additionally, several phenomena about speech perception are discussed on the basis of this study.

关键词： excitation pattern speech perception phonetic quality steady-state vowel

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Continuous high-temperature rapid nanomanufacturing of electrocatalysts

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Nano Research 2025年第1期18卷 225-235页

作者： Xiaoyang Wang Ziyi Luo Baihua Cui Ziqi Fu Yanchang Liu Weidi Liu Jia Ding Jianrong Zeng Yanan ChenWenbin Hu School of Materials Science and Engineering Tianjin UniversityTianjin 300350China Australian institute for Bioengineering and Nanotechnology The University of QueenslandSt.LuciaBrisbane 4072Australia Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Shanghai institute of applied Physics Chinese Academy of SciencesShanghai 201800China

Encapsulating metal nanoparticles in carbon shells(Metal@C)to enhance catalytic activity and stability has been certified ***,most existing methods for preparing Metal@C are complex,time-consuming,and lack of *** this study,a novel method that couples the high-temperature shock(HTS)with ultrasonic spray pyrolysis is reported,which can realize facile and scalable production of various Metal@C through the pyrolysis of glucose and metal chloride *** proposed HTS ultrasonic spray pyrolysis offers several advantages,including compact size,short reaction time(~120 ms),and uniform *** the Ni@C-40 nanocomposite as an example,the ultrasmall Ni nanoparticles(~10 nm)with thin carbon protective shells(~2 nm)are uniformly dispersed in the carbon matrix and applied for oxygen evolution reaction(OER)in alkaline *** Ni@C-40 optimized by tuning the thickness of carbon shell exhibits significantly enhanced OER activity with low overpotential of 242 mV at 10 mA·cm^(-2) and stability,which is attributed to the optimized interactions between Ni nanoparticles and carbon *** method also shows promise for continuous pyrolysis synthesis of various extreme materials at ultra-high temperatures using alternative electric heating materials.

关键词： ultrasonic spray pyrolysis high-temperature shock carbon shell oxygen evolution reaction Metal@C nanocomposite

Statistical properties of Chinese semantic networks

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Chinese Science Bulletin 2009年第16期54卷 2781-2785页

作者： LIU HaiTao institute of applied linguistics Communication University of China Beijing 100024 China

Almost all language networks in word and syntactic levels are small-world and scale-free. This raises the questions of whether a language network in deeper semantic or cognitive level also has the similar properties. To answer the question, we built up a Chinese semantic network based on a treebank with semantic role (argument structure) annotation and investigated its global statistical properties. The results show that although semantic network is also small-world and scale-free, it is different from syntactic network in hierarchical structure and K-Nearest-Neighbor correlation.

关键词：语义网络统计性质汉语参数结构统计特性层次结构小世界标度

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