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The Extension Dimension of Subcategories and Recollements of Abelian Categories

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Acta mathematica Sinica,English Series 2024年第4期40卷 1042-1058页

作者： Xin ma Ye Yang peng Zhao Yong HUANG College of Science Henan University of EngineeringZhengzhou 451191P.R.China Department of mathematics Nanjing UniversityNanjing 210093P.R.China

We investigate the behavior of the extension dimension of subcategories of abelian categories under ***Λ',Λ,Λ"be art in algebras such that(modΛ',mod A,modΛ")is a recollement,and let D'and D"be subcategories of modΛand modΛ"*** any n,m≥0,under some conditions,we get dimΩ^(k)(D)≤dimΩ^(n)(D')+dimΩ^(m)(D")+1,where k=max{m,n}and D is the subcategory of modΛglued by D'and D";moreover,we give a sufficient condition such that the converse inequality holds *** applications,some results for Igusa-Todorov subcategories and syzygy finite sub categories are obtained.

关键词： Recollements extension dimension Igusa–Todorov subcategories syzygy finite subcategories

Recent progress in the development of dielectric elastomer materials and their multilayer actuators

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第3期25卷 183-205页

作者： Shengchao JIANG Junbo peng Lvting WANG Hanzhi ma Ye SHI ZJU-UIUC Institute Zhejiang UniversityJiaxing 314400China College of Mechanical Engineering Zhejiang UniversityHangzhou 310058China Department of Polymer Science and Engineering Zhejiang UniversityHangzhou 310058China

Dielectric elastomers(DEs)have emerged as one of the most promising artificial muscle technologies,due to their exceptional properties such as large actuation strain,fast response,high energy density,and flexible processibility for various *** the past two decades,researchers have been working on developing DE materials with improved properties and exploring innovative applications of dielectric elastomer actuators(DEAs).This review article focuses on two main topics:recent material innovation of DEs and development of multilayer stacking processes for DEAs,which are important to promoting commercialization of *** begins by explaining the working principle of a ***,recently developed strategies for preparing new DE materials are introduced,including reducing mechanical stiffness,increasing dielectric permittivity,suppressing viscoelasticity loss,and mitigating electromechanical instability without *** the next section,different multilayer stacking methods for fabricating multilayer DEAs are discussed,including conventional dry stacking,wet stacking,a novel dry stacking method,and micro-fabrication-enabled stacking *** review provides a comprehensive and up-to-date overview of recent developments in high-performance DE materials and multilayer stacking *** highlights the progress made in the field and also discusses potential future directions for further advancements.

关键词： Dielectric elastomer actuator(DEA) Dielectric elastomer(DE) material svnthesis Multilaver stacking method

Conductive edge-warping graphite mesas for robust structural superlubricity

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Science China(Technological Sciences) 2024年第7期67卷 2040-2049页

作者： FENG WeiJia LIU Ying ma Ming peng DeLi NIE JinHui State Key Laboratory of Tribology in Advanced Equipment&Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Center for Nano and Micro Mechanics Tsinghua UniversityBeijing 100084China Institute of Superlubricity Technology Research Institute of Tsinghua University in ShenzhenShenzhen 518057China

Structural superlubricity(SSL) refers to a state of ultralow friction and zero wear when two solid surfaces slide against each other. Recent investigations have identified amorphous carbon at the edge of the graphite mesa as the primary source of friction in such SSL systems. Here, the tensile stress of metal thin film is exploited to engineer vertically conductive edge-warping graphite mesas(EWGM). Through this approach, robust SSL performance is realized, demonstrated by sliding an 8 μm side length square EWGM on an atomically smooth Au substrate for 10000 cycles at a constant voltage of 1 m V. In this SSL system,differential friction coefficients lower than 1.5 × 10^(-4) are achieved, with static contact resistance between EWGM and Au substrate as low as 28Ω and sliding contact resistance as low as 32Ω. Moreover, the EWGM exhibits SSL behavior on polished Si wafer substrates. Furthermore, because of the no-edge contact with the substrate during sliding, friction is independent of the sliding speed of the EWGM. This study presents the first successful fabrication of conductive EWGM. Remarkably, in both EWGM-Au and EWGM-Si SSL systems, the measured frictions are more than one order of magnitude lower than those of ordinary self-retracting graphite mesas with no-edge warping, and no wear is observed during extended current-carrying ***, these findings establish a solid groundwork for the future realization of macroscale conductive SSL systems.

关键词： structural superlubricity graphite mesa contact resistance tensile stress edge warping

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Fake News Detection Based on Text-Modal Dominance and Fusing Multiple Multi-Model Clues

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Computers, materials & Continua 2024年第3期78卷 4399-4416页

作者： Li fang Fu Huanxin peng Changjin ma Yuhan Liu College of Arts and Sciences Northeast Agricultural UniversityHarbin150030China College of Engineering Northeast Agricultural UniversityHarbin150030China

In recent years,how to efficiently and accurately identify multi-model fake news has become more ***,multi-model data provides more evidence but not all are equally ***,social structure information has proven to be effective in fake news detection and how to combine it while reducing the noise information is ***,existing approaches fail to handle these *** paper proposes a multi-model fake news detection framework based on Tex-modal Dominance and fusing Multiple Multi-model Cues(TD-MMC),which utilizes three valuable multi-model clues:text-model importance,text-image complementary,and text-image ***-MMC is dominated by textural content and assisted by image information while using social network information to enhance text *** reduce the irrelevant social structure’s information interference,we use a unidirectional cross-modal attention mechanism to selectively learn the social structure’s features.A cross-modal attention mechanism is adopted to obtain text-image cross-modal features while retaining textual features to reduce the loss of important *** addition,TD-MMC employs a new multi-model loss to improve the model’s generalization *** experiments have been conducted on two public real-world English and Chinese datasets,and the results show that our proposed model outperforms the state-of-the-art methods on classification evaluation metrics.

关键词： Fake news detection cross-modal attention mechanism multi-modal fusion social network transfer learning

Electrodeposited transparent PEDOT for inverted perovskite solar cells:improved charge transport and catalytic performances

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Rare Metals 2021年第9期40卷 2402-2414页

作者： Cong-Tan Zhu Ying Yang Fei-Yu Lin Yuan Luo shu-peng ma Liu Zhu Xue-Yi Guo School of Metallurgy and Environment Central South UniversityChangsha 410083China First Rare materials Co. LtdQingyuan 511517China

The acidic, corrosive effect of sodium polystyrene sulfonate(PSS) in poly 3,4-ethylenedioxythiophene:sodium polystyrene sulfonate(PEDOT:PSS) limits the stability of inverted perovskite solar cells(PSCs) based on the ITO/PEDOT:PSS/perovskite/PCBM/BCP/Ag structure. In this work, a poly 3,4-ethylenedioxythiophene(PEDOT) hole transport layer(HTL) with high hole mobility and good catalytic performance was prepared by electrochemical cyclic voltammetry(CV) method for inverted PSCs. By controlling the CV cycles(from 1 to 5 cycles) and EDOT monomer solution concentration(from0.5 to 2.0 mmol·L^(-1)) of electrochemical deposition, the thickness, morphology, optical and electrochemical properties of PEDOT could be accurately adjusted. The optimal photovoltaic performance with current density(J_(sc)) of 22.19 ma·cm^(-2), open circuit voltage(V_(oc)) of 0.94 V, fill factor(FF) of 0.65 and photoelectric conversion efficiency of 13.56% was obtained when deposition of PEDOT with 1 CV cycle and EDOT concentration of 0.5 mmol·L^(-1). At this point, the perovskite showed good crystallization,optimal optical, charge transport and recombination performance, resulting in better V_(oc)and photoelectric conversion efficiency(PCE) compared to the devices with higher CV cycle numbers and 3,4-ethylenedioxythiophene(EDOT) concentration. For comparison with spin-coated PEDOT:PSS, the device with electrodeposited PEDOT showed improved J_(sc)and comparable V_(oc), which may result from its better charge transport and catalytic *** device with spin-coated PEDOT:PSS showed photoelectric conversion efficiency of 12.25%, which was lower than that based on electrodeposited PEDOT(13.56%) with1 CV cycles and 0.5 mmol·L^(-1) EDOT concentration. And the device with electrodeposited PEDOT as HTLs showed more excellent air stability. In ambient air((32 ± 5) ℃ and RH: 70% ± 20%), it still maintained more than 80%of the initial photoelectric conversion efficiency after1000 h. In comparison, the photoe

关键词： Electrochemically cyclic voltammetry Inverted perovskite solar cells Electrodeposited PEDOT Hole mobility Tafel analysis

Anti-aging performance improvement and enhanced combustion efficiency of boron via the coating of PDA

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Defence Technology（防务技术） 2024年第3期33卷 399-410页

作者： shuai ma Qinghai shu Mengyang Zhang Hongyu Huang Yansong Shi Xijuan Lv shuai Zhao School of materials Science and Engineering Beijing Institute of TechnologyBeijing100081China Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement(MOE) Beijing Key Lab of Nanophotonics&Ultrafine Optoelectronic SystemsSchool of PhysicsBeijing Institute of TechnologyBeijing100081China Tangshan Research Institute of Beijing Institute of Technology Tangshan063000HebeiChina

Boron is an ambitious fuel in energetic materials since its high heat release values,but its application is prohibited by low combustion efficiency and oxidization during *** polydopamine(PDA)was introduced into boron particles,investigating the impact of PDA content on the energetic behavior of *** results indicated that the PDA coating formed a fishing net structure on the surface of boron *** heat release results showed that the combustion calorific value of B@PDA was higher than that of the raw ***,the actual combustion heat of boron powder in B@10%PDA increased by 38.08%.Meanwhile,the DSC peak temperature decreased by 100.65℃under similar oxidation rate compared to raw ***,the B@PDA@AP and B@AP composites were prepared,and their combustion properties were *** was demonstrated that B@10%PDA@AP exhibited superior performance in terms of peak pressure and burning time,*** peak pressure is 12.43 kPa more than B@AP and burning time is 2.22 times higher than B@***,the coating of PDA effectively inhibits the oxidization of boron during storage and enhances the energetic behavior of boron and corresponding composites.

关键词： Boron particles Polydopamine Anti-aging performance improvement Heat release

Temperature trends and its elevation-dependent warming over the Qilian Mountains

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Journal of Mountain Science 2024年第2期21卷 500-510页

作者： ZHAO peng HE Zhibin ma Dengke WANG Wen QIAN Lihui School of Computer Science Huainan Normal UniversityHuainan 232038China Linze Inland River Basin Research Station Key Laboratory of Inland River Basin ScienceNorthwest Institute of Eco-Environment and ResourceChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

Understanding temperature variability especially elevation dependent warming(EDW)in high-elevation mountain regions is critical for assessing the impacts of climate change on water resources including glacier melt,degradation of soils,and active layer *** means that temperature is warming faster with the increase of *** this study,we used observed temperature data during 1979-2017 from 23 meteorological stations in the Qilian Mountains(QLM)to analyze temperature trend with mann-Kendall(MK)test and Sen’s slope *** showed that the warming trends for the annual temperature followed the order of T_min>T_mean>T_max and with a shift both occurred in *** and summer temperature have a higher increasing trend than that in autumn and winter.T_mean shifts occurred in 1996 for spring and summer,in 1997 for autumn and winter.T_max shifts occurred in 1997 for spring and 1996 for summer.T_min shifts occurred in 1997 for spring,summer and winter as well as in 1999 for *** mean diurnal temperature range(DTR)shows a significant decreasing trend(-0.18°C/10a)from 1979 to *** mean DTR shows a significant decreasing trend(-0.26°C/10a)from 1979 to 2017 with a shift occurred in *** removing longitude and latitude factors,we can learn that the warming enhancement rate of average annual temperature is 0.0673°C/km/10a,indicating that the temperature warming trend is accelerating with the continuous increase of *** increase rate of elevation temperature is 0.0371°C/km/10a in spring,0.0457°C/km/10a in summer,0.0707°C/km/10a in autumn,and 0.0606°C/km/10a in winter,which indicates that there is a clear EDW in the *** main causes of warming in the Qilian Mountains are human activities,cloudiness,ice-snow feedback and El Nino phenomenon.

关键词： Climate change Qilian Mountains Warming rates DTR Elevation-dependent warming

Universal insertion of molecules in ionic compounds under pressure

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National Science Review 2024年第1期11卷 120-128页

作者： Feng peng Yanming ma Chris J.Pickard Hanyu Liu maosheng Miao College of Physics and Electronic Information Luoyang Normal University Department of Chemistry and Biochemistry California State University Northridge State Key Laboratory of Superhard materials & Key Laboratory of material Simulation Methods and Software of Ministry of Education College of Physics Jilin University International Center of Future Science Jilin University Department of materials Science & Metallurgy University of Cambridge Advanced Institute for materials Research Tohoku University Department of Earth Science University of California Santa Barbara

Using first-principles calculations and crystal structure search methods, we found that many covalently bonded molecules such as H2, N2, CO2, NH3, H2O and CH4may react with NaC l, a prototype ionic solid,and form stable compounds under pressure while retaining their molecular structure. These molecules,despite whether they are homonuclear or heteronuclear, polar or non-polar, small or large, do not show strong chemical interactions with surrounding Na and Cl ions. In contrast, the most stable molecule among all examples, N2, is found to transform into cyclo-N5-anions while reacting with NaC l under high pressures. It provides a new route to synthesize pentazolates, which are promising green energy materials with high energy density. Our work demonstrates a unique and universal hybridization propensity of covalently bonded molecules and solid compounds under pressure. This surprising miscibility suggests possible mixing regions between the molecular and rock layers in the interiors of large planets.

关键词： molecule-solid hybrid materials high-pressure crystal structure prediction density functional theory planet interior

Enrichment of anammox biomass during mainstream wastewater treatment driven by achievement of partial denitrification through the addition of bio-carriers

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Journal of Environmental Sciences 2024年第3期137卷 181-194页

作者： Yuqing ma Bo Wang Xiaodi Li shuo Wang Wen Wang Yongzhen peng National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology Engineering Research Center of BeijingBeijing University of TechnologyBeijing 100124China

Anammox is widely considered as the most cost-effective and sustainable process for nitrogen ***,how to achieve the enrichment of anammox biomass remains a challenge for its large-scale application,especially in mainstream wastewater *** this study,the feasibility of enrichment of anammox biomass was explored through the realization of partial denitrification and the addition of *** using ordinary activated sludge,a sequencing batch reactor(SBR)followed by an up-fow anaerobic sludge bed(UASB)was operated at 25±2℃ for 214 *** long-term operation was divided into five phases,in which SBR and UASB were started-up in Phases I and II,*** eliminating oxygen and adjusting the infow ratios in Phases III-V,advanced nitrogen removal was achieved with the effuent total nitrogen being 4.7 mg/L and the nitrogen removal efficiency being 90.5%in Phase *** in-situ and ex-situ activity tests demonstrated the occurrence of partial denitrification and ***,16S rRNA high-throughput sequencing analysis revealed that Candidatus Brocadia was enriched from below the detection limit to in biofilms(0.4%in SBR,2.2%in UASB)and the foc sludge(0.2%in SBR,1.3%in UASB),while Thauera was mainly detected in the foc sludge(8.1%in SBR,8.8%in UASB),which might play a key role in partial ***,this study provides a novel strategy to enrich anammox biomass driven by rapid achievement of partial denitrification through the addition of bio-carriers,which will improve large-scale application of anammox processes in mainstream wastewater treatment.

关键词： Enrichment Anammox biomass Bio-carriers Partial denitrification mainstream wastewater