检索结果-南通市图书馆

High thermal conductivity and remarkable damping composite gels as thermal interface materials for heat dissipation of chip

在线全文

学校读者我要写书评

暂无评论

Chip 2022年第2期1卷 27-34页

作者： Sheng-Chang Ding Jian-Feng Fan Dong-Yi He Lin-Feng Cai Xiang-liang zeng Lin-Lin Ren Guo-Ping Du xiao-liang zeng Rong Sun Shenzhen Institute of Advanced Electronic Materials Shenzhen Institute of Ad-vanced TechnologyChinese Academy of SciencesShenzhen518055China School of Physics and Materials Science Nanchang UniversityNanchang 330031China

The emerging applications of composite gels as thermal interface ma-terials(TIMs)for chip heat dissipation in intelligent vehicle and wear-able devices require high thermal conductivity and remarkable damp-ing ***,thermal conductivity and damping proper-ties are usually correlated and coupled each ***,inspired by Maxwell theory and adhesion mechanism of gecko’s setae,we present a strategy to fabricate polydimethylsiloxane-based composite gels in-tegrating high thermal conductivity and remarkable damping prop-erties over a broad frequency and temperature *** multiple relaxation modes of dangling chains and the dynamic interaction be-tween the dangling chains and aluminum fillers can efficiently dis-sipate the vibration energy,endowing the composite gels with ultra-high damping property(tanδ>0.3)over a broad frequency(0.01-100 Hz)and temperature range(-50-150°C),which exceeds typi-cal state-of-the-art damping *** dangling chains also com-fort to the interfaces between polymer matrix and aluminum via van der Waals interaction,resulting in high thermal conductivity(4.72±0.04 W m-1 K-1).Using the polydimethylsiloxane-based composite gel as TIMs,we demonstrate effective heat dissipation in chip oper-ating under vigorous *** believe that our strategy could be applied to a wide range of composite gels and lead to the devel-opment of high-performance composite gels as TIMs for chip heat dissipation.

关键词： Thermal interface materials Composite gels Damping Ther-mal conductivity Dangling chains

Achieving structurally stable O3-type layered oxide cathodes through site-specific cation-anion co-substitution for sodium-ion batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第6期93卷 411-418,I0011页

作者： Yihao Shen Chen Cheng xiao Xia Lei Wang Xi Zhou Pan zeng Jianrong zeng liang Zhang Institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123JiangsuChina Institute for Advanced Study School of Mechanical EngineeringChengdu UniversityChengdu 610106SichuanChina Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China Jiangsu Key Laboratory of Advanced Negative Carbon Technologies Soochow UniversitySuzhou 215123JiangsuChina

O3-type layered oxides have garnered great attention as cathode materials for sodium-ion batteries because of their abundant reserves and high theoretical ***,challenges persist in the form of uncontrollable phase transitions and intricate Na^(+)diffusion pathways during cycling,resulting in compromised structural stability and reduced capacity over *** study introduces a special approach employing site-specific Ca/F co-substitution within the layered structure of O_(3)-NaNi_(0.5)Mn_(0.5)O_(2) to effectively address these ***,the strategically site-specific doping of Ca into Na sites and F into O sites not only expands the Na^(+)diffusion pathways but also orchestrates a mild phase transition by suppressing the Na^(+)/vacancy ordering and providing strong metal-oxygen bonding strength,*** as-synthesized Na_(0.95)Ca_(0.05)Ni_(0.5)Mn_(0.5)O_(1.95)F_(0.05)(NNMO-CaF)exhibits a mild O3→O3+O'3→P3 phase transition with minimized interlayer distance variation,leading to enhanced structural integrity and stability over extended *** a result,NNMO-CaF delivers a high specific capacity of 119.5 mA h g^(-1)at a current density of 120 mA g^(-1)with a capacity retention of 87.1%after 100 *** study presents a promising strategy to mitigate the challenges posed by multiple phase transitions and augment Na^(+)diffusion kinetics,thus paving the way for high-performance layered cathode materials in sodium-ion batteries.

关键词： Sodium-ion batteries O3-type layered oxides Site-specific co-doping Phase transition

Aggregation-regulated bioreduction process of graphene oxide by Shewanella bacteria

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第5期69卷 56-62页

作者： Kaixin Han Yibo zeng Yinghua Lu Ping zeng liang Shen Department of Chemical and Biochemical Engineering College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361005China Chinese Research Academy of Environmental Sciences Beijing 100012China

The bioreduction of graphene oxide(GO)using environmentally functional bacteria such as Shewanella represents a green approach to produce reduced graphene oxide(rGO).This process differs from the chemical reduction that involves instantaneous molecular *** bioreduction,the contact of bacterial cells and GO is considered the rate-limiting *** reveal how the bacteria-GO integration regulates rGO production,the comparative experiments of GO and three Shewanella strains were carried ***-transform infrared spectroscopy,X-ray photoelectron spectroscopy,Raman spectroscopy,and atomic force microscopy were used to characterize the reduction degree and the aggregation *** results showed that a spontaneous aggregation of GO and Shewanella into the condensed entity occurred within 36 h.A positive linear correlation was established,linking three indexes of the aggregation potential,the bacterial reduction ability,and the reduction degree(ID/IG)comprehensively.

关键词： Graphene oxide Reduced graphene oxide Bioreduction Aggregation Shewanella

Extreme climate sparks record boreal wildfires and carbon surge in 2023

在线全文

学校读者我要写书评

暂无评论

The Innovation 2024年第4期5卷 7-8页

作者： Lili liang Shijing liang Zhenzhong zeng School of Environmental Science and Engineering Southern University of Science and TechnologyShenzhen 518055China

While human activities,such as the burning of fossil fuels,are the primary contributors to the increase in atmospheric CO_(2) levels,large-scale wildfires can exacerbate this *** years with extensive and severe wildfires,additional carbon emissions can significantly perturb global carbon budgets,1 thereby impeding existing endeavors to mitigate climate ***,a recent investigation reported a notable surge in carbon emissions originating from boreal forests in 2021,2 reaching an estimated 0.48 gigatons of carbon(Gt C).However,this record proved *** 1 shows that by September 2023,the carbon emissions of boreal forests exhibited an unprecedented increase,primarily attributed to the Canadian boreal region,reaching 0.86 Gt *** consequences extend beyond geographical borders,as wildfires occurring hundreds of kilometers away resulted in the worst air quality in New York and *** increasing severity of boreal forest wildfires is accompanied by growing public concern,suggesting the potential proximity to or crossing of a critical tipping point in the ecological functioning of boreal forests.

关键词： surge record Figure

Cigarette Use and Secondhand Smoke Exposure Among Secondary School Students—China,2023

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China CDC weekly 2024年第22期6卷 509-515页

作者： Xinying zeng Shiwei Liu Lin xiao Tobacco Control Office Chinese Center for Disease Control and PreventionBeijingChina

What is already known about this topic?In 2021,the prevalence of experimental and current cigarette use among secondary school students in China stood at 16.7%and 4.7%,***,39.9%of these students were exposed to secondhand smoke at *** is added by this report?In comparison to 2021,the prevalence of current cigarette use remained unchanged at 4.2%in 2023,whereas experimental use declined to 13.7%.Notably,rates were significantly higher among vocational senior high school(VSHS)students relative to their peers in senior high school(SHS)and junior high school(JHS).Furthermore,exposure to secondhand smoke in schools decreased to 35.4%in 2023 from previously recorded levels,with more pronounced reductions observed in JHS and SHS populations and no notable change among VSHS *** are the implications for public health practice?Targeted tobacco control policies are imperative for secondary school students,including the establishment of smoke-free school ***,it is crucial to pay close attention to the needs of VSHS students.

关键词： smoke unchanged senior

Revisit of GeV Gamma-Ray Emission from Orion B with the Fermi Large Area Telescope

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第9期24卷 128-135页

作者： Wei zeng xiao-Na Sun Rui-Zhi Yang Jia-Chun He Zhao-Dong Shi Ting-Ting Ge Yun-Feng liang En-Wei liang Guangxi Key Laboratory for Relativistic Astrophysics School of Physics Science and TechnologyGuangxi UniversityNanning 530004China Department of Astronomy School of Physical SciencesUniversity of Science and Technology of ChinaHefei 230026China CAS Key Labrotory for Research in Galaxies and Cosmology University of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China

We revisit the γ-ray emission above 300 Me V towards the massive star-forming region of Orion B by adopting14 yr observations with the Fermi Large Area Telescope and utilizing the updated software *** extended γ-ray emission region around Orion B is resolved into two components(region Ⅰ and region Ⅱ).The γ-ray spectrum of region I agrees with the predicted γ-ray spectrum assuming the cosmic ray(CR)density is the same as that of Alpha Magnetic Spectrometer(AMS-02)measured ***γ-ray emissivity of region II appears to be deficit at low energy band(E<3 GeV).Through modeling we find that CR densities exhibit a significant deficit below 20 Ge V,which may be caused by a slow diffusion inside the dense *** is probably caused by an increased magnetic field whose strength increases with the gas density.

关键词： (ISM:)cosmic rays gamma-rays:ISM (Galaxy:)open clusters and associations:individual(NGC 2023 NGC 2024 NGC 2068 and NGC 2071)

Dual template-induced construction of three-dimensional porous SiO2/NC/Co-CNTs heterostructure with highly dispersed active sites for efficient oxygen evolution reaction

在线全文

学校读者我要写书评

暂无评论

Tungsten 2024年第3期6卷 585-595页

作者： Hai-Qi Zhang xiao-Jun zeng Qing-Qing Zhang Zu-liang Zhang Chu-Long Jin Rong-Hai Yu School of Materials Science and Engineering Jingdezhen Ceramic University School of Materials Science and Engineering Beihang University

The development and exploration of efficient and economical electrocatalysts for oxygen evolution reaction（OER） represents the main bottleneck to unlocking a sustainable energy scenario based on elec trocataly tic water *** scale integration of three-dimensional（3D） porous heterostructure with highly dispersed active sites and good structural stability is ***,a dual template route is developed to construct the 3D porous SiO2/nitrogen-doped carbon（NC）/Co-carbon nano tubes（CNTs） hetero ***,the hard template（SiO2nano spheres） contributes to 3D porous structure,increases the specific surface area,and promotes the contact area of the *** the same time,the soft template（basic zinc carbonate） can control the growth of 1D CNTs and facilitate the exposure of the active ***,3D porous SiO2/NC/Co-CNTs hetero structure inherits highly dispersed Co nanoparticles coated by *** conductive channels and abundant N hetero atoms doping are reasonably constructed by a dual template ***,SiO2/NC/Co-CNTs catalyst provides an extraordinary activity for the OER in alkaline media,with a low overpotential of 298 mV at a current density of 10 mA·***,SiO2/NC/Co-CNTs hetero structure enables excellent long-term durability with a 10 mV decay in overpotential after 3000 cyclic voltammetry cycles,and 97% remain in current density over 20 *** is believed that this dual template strategy can provide a new and simple way to construct a highly dispersed active site in electrocatalysts.

关键词： Dual template High dispersion Porous heterostructure Conductive channels Oxygen evolution reaction

Constructing Built-In Electric Fields with Semiconductor Junctions and Schottky Junctions Based on Mo-MXene/Mo-Metal Sulfides for Electromagnetic Response

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第10期16卷 453-473页

作者： xiaojun zeng xiao Jiang Ya Ning Yanfeng Gao Renchao Che School of Materials Science and Engineering Jingdezhen Ceramic UniversityJingdezhen 333403People's Republic of China School of Materials Science and Engineering Shanghai UniversityShanghai 200444People's Republic of China Laboratory of Advanced Materials Shanghai Key Lab of Molecular Catalysis and Innovative MaterialsAcademy for Engineering and TechnologyFudan UniversityShanghai 200438People's Republic of China Zhejiang Laboratory Hangzhou 311100People's Republic of China

The exploration of novel multivariate heterostructures has emerged as a pivotal strategy for developing high-performance electromagnetic wave(EMW)absorption ***,the loss mechanism in traditional heterostructures is relatively simple,guided by empirical observations,and is not *** this work,we presented a novel semiconductor-semiconductor-metal heterostructure sys-tem,Mo-MXene/Mo-metal sulfides(metal=Sn,Fe,Mn,Co,Ni,Zn,and Cu),including semiconductor junctions and Mott-Schottky *** skillfully combining these distinct functional components(Mo-MXene,MoS_(2),metal sulfides),we can engineer a multiple heterogeneous interface with superior absorption capabilities,broad effective absorption bandwidths,and ultrathin matching *** successful establishment of semiconductor-semiconductor-metal heterostructures gives rise to a built-in electric field that intensifies electron transfer,as confirmed by density functional theory,which collaborates with multiple dielectric polarization mechanisms to substantially amplify EMW *** detailed a successful synthesis of a series of Mo-MXene/Mo-metal sulfides featuring both semiconductor-semiconductor and semiconductor-metal *** achievements were most pronounced in Mo-MXene/Mo-Sn sulfide,which achieved remarkable reflection loss values of-70.6 dB at a matching thickness of only 1.885 *** cross-section calculations indicate that these MXene/Mo-metal sulfides have tremendous potential in practical military stealth *** work marks a departure from conventional component design limitations and presents a novel pathway for the creation of advanced MXene-based composites with potent EMW absorption capabilities.

关键词： Semiconductor-semiconductor-metal heterostructure Semiconductor junctions Mott-Schottky junctions Built-in electric field Electromagnetic wave absorption

Optically levitated micro gyroscopes with an MHz rotational vaterite rotor

在线全文

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第3期10卷 219-227页

作者： Kai zeng Xiangming Xu Yulie Wu Xuezhong Wu Dingbang xiao College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China College of Information and Communication National University of Defense TechnologyWuhan 430000China Key Laboratory of Satellite Navigation Technology National University of Defense TechnologyChangsha 410073China

The field of levitated optomechanics has experienced significant advancements in manipulating the translational and rotational dynamics of optically levitated particles and exploring their sensing *** concept of using optically levitated particles as gyroscopes to measure angular motion has long been explored but has not yet been proven either theoretically or *** this study,we present the first rotor gyroscope based on optically levitated high-speed rotating *** gyroscope is composed of a micrometer-size ellipsoidal vaterite particle that is driven to rotate at MHz frequencies in a vacuum *** an external angular velocity is input,the optical axis deviates from its initial position,resulting in changes in the frequency and amplitude of the rotational *** analyzing these changes,the angular velocity of the input can be accurately detected,making it the smallest rotor gyroscope in the *** angular rate bias instability of the gyroscope is measured to be 0.08°/s and can be further improved to as low as 10^(−9)°/h theoretically by cooling the motion and increasing the angular moment of the levitated *** work opens a new application paradigm for levitated optomechanical systems and may pave the way for the development of quantum rotor gyroscopes.

关键词： particles rotational angular