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Defence Technology（防务技术） 2022年第9期18卷 1602-1621页

作者： hai-jiao xue Yan-qing Wu Kun Yang Yi Wu State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China School of Aerospace Engineering Beijing Institute of TechnologyBeijing100081China

Investigating the damage and ignition behaviors of polymer-bonded explosive(PBX) under a coupled impact and high-temperature loading condition is required for the safe use of charged PBXs. An improved combined microcrack and microvoid model(CMM) was developed for better describing the thermal effects of deformation, damage, and ignition responses of PBXs. The main features of the model under typical dynamic loadings(i.e. uniaxial tension and compression, and lateral confinement) at different initial temperature were first studied. And then the effects of temperature on impact-shear sensitivity of HMX-based PBXs were investigated. The results showed that the ignition threshold velocity of shear-crack hotspots exhibits an increase from 260 to 270 to 315-325 m/s when initial temperature increases from 301 to 348 K;and then the threshold velocity decreases to 290-300 m/s with the initial temperature continually increasing to 378 K. The predicted ignition threshold velocity level of the explosives under coupled impact and high temperature loading conditions were consistent with the experimental data.

关键词： PBX Thermal-mechanical coupling Numerical simulation Impact Sensitivity

Synthesis of uniform two-dimensional MoS_(2) films via thermal evaporation

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Nano Research 2024年第4期17卷 3217-3223页

作者： xue-Wei Lu Zhewei Li Chen-Kai Yang Weijia Mou Liying jiao Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education Department of ChemistryTsinghua UniversityBeijing 100084China

Two-dimensional(2D)molybdenum disulfide(MoS_(2))holds great potential for various applications such as electronic devices,catalysis,lubrication,anti-corrosion and so on.Thermal evaporation is a versatile thin film deposition technique,however,the conventional thermal evaporation techniques face challenges in producing uniform thin films of MoS_(2) due to its high melting temperature of 1375℃.As a result,only thick and rough MoS_(2) films can be obtained using these methods.To address this issue,we have designed a vacuum thermal evaporation system specifically for large-scale preparation of MoS_(2) thin films.By using K2MoS4 as the precursor,we achieved reliable deposition of uniform polycrystalline MoS_(2) thin films with a size of 50 mm×50 mm and controllable thickness ranging from 0.8 to 2.4 nm.This approach also allows for patterned deposition of MoS_(2) using shadow masks and sequential deposition of MoS_(2) and tungsten disulfide(WS_(2)),similar to conventional thermal evaporation techniques.Moreover,we have demonstrated the potential applications of the obtained MoS_(2) thin films in field effect transistors(FETs),memristors and electrocatalysts for hydrogen evolution reaction(HER).

关键词： thermal evaporation molybdenum disulfide two-dimensional memristors hydrogen evolution reaction

Carbon dots-derived three-dimensional-ordered macroporous host with high penetrability and catalytic activity for LSBs under lean electrolyte

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Rare Metals 2024年第6期43卷 2560-2573页

作者： jiao-Zi Duan Hua-Yu Pei Quan Yang xue Li Xin Ba xue Yong Jun-Ling Guo Si-Yu Lu Green Catalysis Center College of ChemistryZhengzhou University Country State Center for International Cooperation On Designer Low-Carbon & Environmental Materials School of Materials Science and EngineeringZhengzhou University Hubei Institute of Quality Supervision Inspection Department of Chemistry University of Sheffield

The practical energy density of lithium-sulfur batteries（LSBs） is seriously limited by the high electrolyte-to-sulfur ratios（E/S）.The E/S can be reduced by employing hosts with easy-to-infiltrate structure that ensures the uniform distribution of a lean electrolyte and high catalytic activity that can suppress "shuttle effect" via accelerating the slow conversion of soluble poly sulfides to insoluble sulfides.Among the easy-to-infiltrate structures,the three-dimensional-ordered macroporous（3DOM）structure is easier to scale preparation and more suitable for the existing industrial processes.However,it is difficult to obtain the 3DOM with（1） high penetrability due to the high viscosity of frequently-used organic polymer precursors and（2） high catalytic activity due to the low confinement effect,meaning that uniformly dispersed small-sized catalytic materials are difficult to load on 3DOM.Herein,using carbon dots（CDs） with both organic and inorganic properties as a precursor and aggregation limiting agent,a 3DOM host with high penetrability and homodispersed Ni particles of small sizes（Ni-CDs-3DOM）was synthesized.In this host:（1） CDs precursor with suitable viscosity can improve the penetrability.（2） CDs can effectively inhibit the agglomeration of Ni particles.（3） Uniformly dispersed small-size Ni particles offer high-efficiency catalytic activity toward sulfur reactions.Consequently,the Ni-CDs-3DOM/sulfur cathode exhibits high sulfur utilization and stable cycling performance even under high sulfur loading(5.5 mg·cm-1) and low E/S(6.5 μl·mg-1).This work indicates the usefulness of CDs in constructing hosts for LSBs with high energy density.

关键词： Lithium–sulfur batteries Carbon dots Catalytic action Easy-to-infiltrate structure Lean electrolyte

Radial growth in Qinghai spruce is most sensitive to severe drought in the Qilian Mountains of Northwest China

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Journal of Forestry Research 2024年第3期35卷 73-86页

作者： Xuge Wang Liang jiao Ruhong xue Peng Zhang Dashi Du Mengyuan Wei Qian Li College of Geography and Environmental Science Northwest Normal UniversityNo.967Anning East RoadLanzhou 730070People's Republic of China Key Laboratory of Resource Environment and Sustainable Development of Oasis Northwest Normal UniversityLanzhou 730070Gansu ProvincePeople's Republicof China

Global warming and frequent extreme drought events lead to tree death and extensive forest decline,but the underlying mechanism is not clear.In drought years,cambial development is more sensitive to climate change,but in different phenological stages,the response rela-tionship is nonlinear.Therefore,the dynamic relationship between tree radial growth and climatic/environmental fac-tors needs to be studied.We thus continuously monitored radial growth of Qinghai spruce(Picea crassifolia Kom.)and environmental factors from January 2021 to November 2022 using point dendrometers and portable meteorological weather stations in the central area of the Qilian Mountains.The relationship and stability between the radial growth of Qinghai spruce and environmental factors were compared for different levels of drought in 2021 and 2022.The year 2022 had higher temperatures and less precipitation and was drier than 2021.Compared with 2021,the growing period in 2022 for Qinghai spruce was 10 days shorter,maximum growth rate(Grmax)was 4.5μm·d^(-1) slower,and the initiation of growth was 6 days later.Growth of Qinghai spruce was always restricted by drought,and the stem radial increment(SRI)was more sensitive to precipitation and air relative humidity.Seasonal changes in cumulative radial growth were divided into four phenological stages according to the time of growth onset,cessation,and maximum growth rate(Grmax)of Qinghai spruce.Stability responses of SRI to climate change were stronger in Stage 3 and Stage 4 of 2021 and stronger in Stage 1(initiation growth stage)and Stage 3 of 2022.The results provide important information on the growth of the trees in response to drought and for specific managing forests as the climate warms.

关键词： Picea crassifolia Radial growth dynamics Severe drought Response stability Point dendrometer

Elevation response of above-ground net primary productivity for Picea crassifolia to climate change in Qilian Mountains of Northwest China based on tree rings

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Journal of Geographical Sciences 2024年第1期34卷 146-164页

作者： WU Xuan jiao Liang DU Dashi xue Ruhong WEI Mengyuan ZHANG Peng College of Geography and Environment Science Northwest Normal UniversityLanzhou 730070China Key Laboratory of Resource Environment and Sustainable Development of Oasis Northwest Normal UniversityLanzhou 730070China

Current ecosystem models used to simulate global terrestrial carbon balance generally suggest that terrestrial landscapes are stable and mature,but terrestrial net primary productivity(NPP)data estimated without accounting for disturbances in species composition,environment,structure,and ecological characteristics will reduce the accuracy of the global carbon budget.Therefore,the steady-state assumption and neglect of elevation-related changes in forest NPP is a concern.The Qilian Mountains are located in continental climate zone,and vegetation is highly sensitive to climate change.We quantified aboveground biomass(AGB)and aboveground net primary productivity(ANPP)sequences at three elevations using field-collected tree rings of Picea crassifolia in Qilian Mountains of Northwest China.The results showed that(1)There were significant differences between AGB and ANPP at the three elevations,and the growth rate of AGB was the highest at the low elevation(55.99 t ha^(–1)10a^(–1)).(2)There are differences in the response relationship between the ANPP and climate factors at the three elevations,and drought stress is the main climate signal affecting the change of ANPP.(3)Under the future climate scenario,drought stress intensifies,and the predicted decline trend of ANPP at the three elevations from mid-century to the end of this century is–0.025 t ha^(–1)10a^(–1),respectively;–0.022 t ha^(–1)10a^(–1);At–0.246 t ha^(–1)10a^(–1),the level of forest productivity was significantly degraded.The results reveal the elevation gradient differences in forest productivity levels and provide key information for studying the carbon sink potential of boreal forests.

关键词： global climate change tree ring aboveground net primary productivity aboveground biomass drought stress Qilian Mountains

Mitochondrial sensitive probe with aggregation-induced emission characteristics for early brain diagnosis of Parkinson’s disease

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Aggregate

Aggregate 2024年第1期5卷 216-227页

作者： Liwen Huang Yutong Zhou Di jiao Jing Ren Yilin Qi Heping Wang Yang Shi Dan Ding xue xue State Key Laboratory of Medicinal Chemical Biology College of PharmacyNankai UniversityTianjinP.R.China State Key Laboratory of Medicinal Chemical Biology Key Laboratory of Bioactive MaterialsMinistry of Educationand College of Life SciencesNankai UniversityTianjinP.R.China

The early diagnosis of Parkinson’s disease(PD)provides opportunities for early intervention to slow the progression of neurological degeneration in patients,particularly as the aging population increases in our society.Among a series of pathological features of PD,mitochondria abnormalities have been identified as central event that occurs at the early stage of PD.However,the method for detecting mitochondrial abnormalities-associated early PD has not been fully developed.We herein report a specifically mitochondrial targeting probe(named TPA-BT-SCP)that is able to characterize mitochondria abnormalities for early diagnosis of PD and monitor PD neurodegenerative progress.The probe is an aggregation-induced emission(AIE)probe with a strong positive charge,a 3D distorted molecular structure,and a separated HOMO-LUMO distribution,designed with unique molecular design guidelines.Our research demonstrated that TPA-BT-SCP could emit stable and strong fluorescence,and rapidly accumulate in mitochondria due to the negative charge.After intranasal administration of 1-methy-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced PD mice,TPA-BT-SCP successfully bypassed the blood−brain barrier to light up the brain,allowing the grading of PD severity based on its high sensitivity.Taken together,this work develops a novel AIE probe that exhibits dramatically high sensitivity to mitochondrial changes and enables noninvasive diagnosis of early PD in the brain.

关键词： aggregation-induced emission early diagnosis Parkinson’s disease

A survey of composite robot for aviation intelligent manufacturing application

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High Technology Letters 2024年第1期30卷 85-98页

作者：陶永 xue jiao WEI Hongxing LIU haitao GAO He WANG Tianmiao School of Mechanical Engineering&Automation Beihang UniversityBeijing 100191P.R.China Research Institute of Aero Engine Beihang UniversityBeijing 100191P.R.China

With the rapid development of the aviation industry,the development of intelligent manufacturing equipment represented by composite robots has been paid close attention by the aviation industry.Based on the analysis of the background and main structure function of composite robots,this paper focuses on the analysis of key technologies such as composite robot hardware design,visual sensing and planning system,integrated control of‘hands,feet,and eyes',multi-robot collaborative operation,and safety.The typical applications of composite robots in aviation intelligent manufacturing such as automatic drilling and connection of aircraft,aircraft surface spraying and finishing,parts handling,aircraft measurement,and inspection are presented.The development trends such as standardization of composite robots,integration of‘5G+cloud computing+AI',and fusion of intelligent sensors are proposed.

关键词： aviation manufacturing composite robot key technology development trend safety

Rational design of vitamin C/defective carbon van der Waals heterostructure for enhanced activity,durability and storage stability toward oxygen reduction reaction

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Journal of Energy Chemistry 2024年第1期88卷 103-111,I0003页

作者： Ruiqi Cheng Kaiqi Li Huanxin Li Tianshuo Zhao Yibo Wang Qingyue xue jiao Zhang Chaopeng Fu Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Christopher Ingold Laboratory Department of ChemistryUniversity College LondonLondon WC1H 0AJUK Department of Chemistry Physical&Theoretical Chemistry LaboratoryUniversity of OxfordSouth Parks RoadOxford OX13QZUK

Metal-free defective carbon materials with abundant active sites have been widely studied as low-cost and efficient oxygen reduction reaction(ORR)electrocatalysts in metal-air batteries.However,the active sites in defective carbon are easily subjected to serious oxidation or hydroxylation during ORR or storage,leading to rapid degradation of activity.Herein,we design a van der Waals heterostructure comprised of vitamin C(VC)and defective carbon(DC)to not only boost the activity but also enhance the durability and storage stability of the DC-VC electrocatalyst.The formation of VC van der Waals between DC and VC is demonstrated to be an effective strategy to protect the defect active sites from oxidation and hydroxylation degradation,thus significantly enhancing the electrochemical durability and storage anti-aging performance.Moreover,the DC-VC van der Waals can reduce the reaction energy barrier to facilitate the ORR.These findings are also confirmed by operando Fourier transform infrared spectroscopy and density functional theory calculations.It is necessary to mention that the preparation of this DC-VC electrocatalyst can be scaled up,and the ORR performance of the largely produced electrocatalyst is demonstrated to be very consistent.Furthermore,the DC-VC-based aluminum-air batteries display very competitive power density with good performance maintenance.

关键词： Van der Waals heterostructure Oxygen reduction reaction Stability Scalable production Aluminum-air battery

Strong light–matter interactions based on excitons and the abnormal all-dielectric anapole mode with both large field enhancement and low loss

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Photonics Research 2024年第4期12卷 854-864页

作者： YAN-HUI DENG YU-WEI LU HOU-jiao ZHANG ZHONG-HONG SHI ZHANG-KAI ZHOU xue-HUA WANG State Key Laboratory of Optoelectronic Materials and Technologies School of PhysicsSun Yat-sen UniversityGuangzhou 510275China Quantum Science Center of Guangdong–Hong Kong–Macao Greater Bay Area(Guangdong) Shenzhen 518045China

The room temperature strong coupling between the photonic modes of micro/nanocavities and quantum emitters(QEs) can bring about promising advantages for fundamental and applied physics.Improving the electric fields(EFs) by using plasmonic modes and reducing their losses by applying dielectric nanocavities are widely employed approaches to achieve room temperature strong coupling.However,ideal photonic modes with both large EFs and low loss have been lacking.Herein,we propose the abnormal anapole mode (AAM),showing both a strong EF enhancement of~70-fold (comparable to plasmonic modes) and a low loss of 34 meV,which is much smaller than previous records of isolated all-dielectric nanocavities.Besides realizing strong coupling,we further show that by replacing the normal anapole mode with the AAM,the lasing threshold of the AAM-coupled QEs can be reduced by one order of magnitude,implying a vital step toward on-chip integration of nanophotonic devices.

关键词： dielectric mode coupling

Two sandwich-type uranyl-containing polytungstates catalyze aerobic synthesis of benzimidazoles

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Rare Metals 2024年第3期43卷 1316-1322页

作者： Yu-Feng Liu Qi-Long Hu xue-jiao Chen Ke Li Pei Luo Guo-Ping Yang School of Chemistry and Material Science Jiangxi Province Key Laboratory of Synthetic ChemistryJiangxi Key Laboratory for Mass Spectrometry and InstrumentationEast China University of TechnologyNanchang330013China School of Environmental Science and Engineering Southern University of Science and TechnologyShenzhen518055China

Diversified synthetic strategies are extremely important for the structural diversity of uranium-containing polyoxometalates(U-POMs)and their functional expansion.Herein,two sandwich-type U-POMs were reported,which are Na_(5.6)K_(6.4)[(UO_(2))(H_(2)O)(TeW_(9)O_(33))]_(2)·21H_(2)O(UTeW_(9))and Na_(8.9)K_(2.7)H_(1.19)[K_(0.79)(UO_(2))_(2.21)(PW_(9)O_(34))_(2)]·12H_(2)O(UPW_9)using in-situ strategy and lacunary precursor strategy,respectively.UTeW_9 shows a typical Keggin-typeopen or half-sandwich configuration.

关键词： configuration expansion sandwich