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Assessment of two quasi-static approaches to mimic repeated impact response and damage behaviour of CFRP laminates

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Chinese Journal of Aeronautics 2023年第8期36卷 101-114页

作者： Lubin HUO Dries verstraeten René ALDERLIEStEN Structural Integrity&Composites Group Faculty of Aerospace EngineeringDelft University of TechnologyP.O.Box 50582600 GB Delftthe Netherlands

Full impact damage tolerance assessment requires the ability to properly mimic the repeated impact response and damage behaviour of composite materials using quasi-static *** this aim,this paper reports an experimental investigation evaluating two quasi-static methods for mimicking repeated impact response and damage behaviour of Carbon Fibre Reinforced Polymer(CFRP)composite *** this study,an 8.45-J single impact was repeated 225 times and mimicked with 225 times 6.51-J quasi-static(energy equivalent)indentations and with 225 quasi-static(force equivalent)indentations following the recorded impact peak force *** show that the loading rate and the inertial effect are the two major factors affecting the responses of the composite laminates under out-of-plane concentrated *** the energyand force-equivalent quasi-static indentations failed to reproduce the impact responses greatly associated with high loading rate and inertial *** force-equivalent quasi-static indentations were performed in a semi-automatic way and induced damage states more similar to those of the repeated impacts than those of the energy-equivalent quasi-static indentations,whereas the latter can be better automated and has better reproducibility compared to that of the repeated impact responses,as it is less dependent on high loading rate and inertial effect.

关键词： Composite laminates Damage detection Damage characterization Low-velocityimpact Quasi-static indentation thermoset composites

A field parcel-oriented approach to evaluate the crop cover-management factor and time-distributed erosion risk in Europe

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International Soil and Water Conservation Research 2023年第1期11卷 43-59页

作者： Francis Matthews Gert.verstraeten Pasquale Borrelli Panos Panagos European Commission Joint Research Centre(JRC)IspraItaly Department of Earth and Environmental Sciences KU LeuvenBelgium Department of Science Roma Tre University00146RomeItaly

the crop cover-management(C-)factor in arable landscapes describes the soil erosion susceptibility associated with seasonally cultivated *** informatic and computational limitations have led many modelling studies to prescribe C-factor values and assume spatial and temporal ***,the multiple influencing factors ranging from parcel-scale crop cultivation and management to regional-scale rainfall regimes motivates new methods to capture this variation when identifying at-risk ***,we define a multi-component method to derive the C-factor by associating time series of canopy and residue surface cover from Sentinel-2 and climate-specific rainfall erosivity with Integrated Administration and Control System(IACS)field parcel data from European Union member states.A scalable and standardised method is emphasised to increase the future interoperability and inter-comparability of soil erosion modelling studies deploying the ***,field parcel simu-lation units with associated crop declarations provide a new reference scale to link predictions of soil erosion risk with specific management decisions and declarations by *** implementing the method on a homogenised subsample of 8600 field parcels covering available IACS regions,several key findings are outlined:1)time series information provides new opportunities to predict the time-criticality of erosion in specific crop cultivations,2)the varying(a-)synchronicity between seasonal crop canopy cover and heavy rainstorms means that spatial variability is inherent within the C-factor across Europe,and 3)the addition of agricultural management practices(*** practice de-scriptions)to open-access IACS repositories can facilitate more comprehensive evaluations of the C-factor and soil erosion risk.

关键词： C-factor Soil erosion Modelling Remote sensing Crop-phenology IACS data Soil conservation Europe

transport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 177-192页

作者： M.NAVEED M.IMRAN t.ASGHAR Z.ABBAS Department of Mathematics Division of Science and TechnologyUniversity of Education Department of Mathematics The Islamia University of Bahawalpur

this paper examines the transport analysis, including both heat transfer and mass transfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. the influence of magnetic fields is also inspected in terms of their physical characteristics. to depict the phenomena of transport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as partial differential equations(PDEs)for momentum, concentration, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAM).the effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concentration, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass transfer rate, heat transfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

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Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： R.A.JAFARI-tALOOKOLAEI H.GHANDVAR E.JUMAEV S.KHAtIR t.CUONG-LE School of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for Engineering Application and technology Solutions Ho Chi Minh City Open University

this paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. the strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. the curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and transient response of the system are determined. the accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANSYS, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

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Elan DRC-e等离子体质谱仪在食品分析中的应用

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岩矿测试 2009年第1期28卷 83-84页

作者： verstraeten David 美国PerkinElmer公司分析科学部比利时办事处

了解食品中营养元素和有害元素的组成十分重要,食品分析一般要求测定其中的高含量(mg/L)组分,也需要测定其中的低含量(μg/L)组分。传统的食品样品分析需要采用多种仪器方法,如用火焰原子吸收光谱法(FAAS)测定食品中的高含量组分,而使... 详细信息

了解食品中营养元素和有害元素的组成十分重要,食品分析一般要求测定其中的高含量(mg/L)组分,也需要测定其中的低含量(μg/L)组分。传统的食品样品分析需要采用多种仪器方法,如用火焰原子吸收光谱法(FAAS)测定食品中的高含量组分,而使用石墨炉原子吸收光谱法(GFAA)测定其中的痕量组分。随着电感耦合等离子体质谱(ICP-MS)技术的不断发展,以上食品样品分析的挑战可在带有动态反应池(DRC)技术的ICP-MS上实现。目前已报道了多篇Elan DRC型ICP-MS应用于食品分析的文献。Elan DRC型ICP-MS多项独特的设计使其非常适合于食品分析。某些高含量元素会使检测器达到饱和,Elan DRC型ICP-MS可以选择性地抑制信号,使得食品中的高含量元素分析成为可能,同时延长了检测器的寿命[6-7]。这些特点对于食品中营养元素的分析是十分重要的。1实验部分1.1等离子体质谱工作条件Elan DRC-e ICP-MS仪工作条件为:十字交叉雾化器、Scott双通道雾室、2 mm石英进样管、射频(RF)功率1500 W。待测元素及其质量数和动态反应池工作条件列于表1。

关键词：食品分析等离子体质谱仪 Elan 石墨炉原子吸收光谱法 DRC 火焰原子吸收光谱法痕量组分应用

Leveraging ROtI map derived from Indonesian GNSS receiver network for advancing study of Equatorial Plasma Bubble in Southeast/East Asia

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Earth and Planetary Physics 2025年第1期9卷 101-116页

作者： Prayitno Abadi Ihsan N.Muafiry teguh N.Pratama Angga Y.Putra Suraina Gatot H.Pramono Sidik t.Wibowo Febrylian F.Chabibi Umar A.Ahmad Wildan P.tresna Asnawi Research Center for Climate and Atmosphere Indonesian National Research and Innovation Agency(BRIN)BandungIndonesia School of Electrical Engineering Telkom UniversityBandungIndonesia Directorate of Laboratory Management Facilities and Science and technology Park Indonesian National Research and Innovation Agency(BRIN)PontianakIndonesia Geophysics Laboratory Master Program in PhysicsUniversitas Gadjah Mada(UGM)YogyakartaIndonesia Research Center for Space Indonesian National Research and Innovation Agency(BRIN)BandungIndonesia Indonesian Geospatial Information Agency(BIG) JakartaIndonesia Research Center for Photonics Indonesian National Research and Innovation Agency(BRIN)Tangerang SelatanIndonesia Department of Earth and Planetary Sciences Hokkaido UniversitySapporoJapan

this paper highlights the crucial role of Indonesia’s GNSS receiver network in advancing Equatorial Plasma Bubble(EPB)studies in Southeast and East Asia,as ionospheric irregularities within EPB can disrupt GNSS signals and degrade positioning *** by the Indonesian Geospatial Information Agency(BIG),the Indonesia Continuously Operating Reference Station(Ina-CORS)network comprises over 300 GNSS receivers spanning equatorial to southern low-latitude ***-CORS is uniquely situated to monitor EPB generation,zonal drift,and dissipation across Southeast *** provide a practical tool for EPB research,by sharing two-dimensional rate of total Electron Content(tEC)change index(ROtI)derived from this *** generate ROtI maps with a 10-minute resolution,and samples from May 2024 are publicly available for further scientific *** preliminary findings from the ROtI maps of Ina-CORS are ***,the Ina-CORS ROtI maps reveal that the irregularities within a broader EPB structure persist longer,increasing the potential for these irregularities to migrate farther ***,we demonstrate that combined ROtI maps from Ina-CORS and GNSS receivers in East Asia and Australia can be used to monitor the development of ionospheric irregularities in Southeast and East *** have demonstrated the combined ROtI maps to capture the development of ionospheric irregularities in the Southeast/East Asian sector during the G5 Geomagnetic Storm on May 11,*** observed simultaneous ionospheric irregularities in Japan and Australia,respectively propagating northwestward and southwestward,before midnight,whereas Southeast Asia’s equatorial and low-latitude regions exhibited irregularities *** sharing ROtI maps from Indonesia and integrating them with regional GNSS networks,researchers can conduct comprehensive EPB studies,enhancing the understanding of EPB behavior across Southeast and East Asia and contributing significantly to ionosphe

关键词： Equatorial Plasma Bubble(EPB) GNSS receivers’network Indonesia Continuously Operating Reference Station(Ina-CORS) ionospheric map Rate of tEC change index(ROtI)map

SAtMODE系统专为交互式电视系统而设计的卫星通讯系统

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SATMODE系统专为交互式电视系统而设计的卫星通讯系统

MICROStRUCtURES AND MECHANICAL PROPERtIES OF IN-SItU Al_2O_3/tiAl COMPOSItES BY EXOtHERMIC DISPERSION MEtHOD

卫星直播与接收系统（机顶盒）应用研讨会

作者： Guy verstraeten Newtec

＜正＞ SAtMODE系统是一个革命性的卫星通讯系统,专为交互式电视服务而设计:该系统以低廉的成本实现了低速率卫星回传的解决方案。由于采用了恒定包络调制模式以及先进高效的信道编码技术,使得其保持了低廉的价格。SAtMODE系统规范即将...

＜正＞ SAtMODE系统是一个革命性的卫星通讯系统,专为交互式电视服务而设计:该系统以低廉的成本实现了低速率卫星回传的解决方案。由于采用了恒定包络调制模式以及先进高效的信道编码技术,使得其保持了低廉的价格。SAtMODE系统规范即将被作为新的欧洲标准,（CENELEC）提交给标准化组织审议。

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Acta Metallurgica Sinica(English Letters) 2008年第6期21卷 437-443页

作者： t.t. Ai Department of Materials Science and Engineering Shaanxi University of Technology Hanzhong 723003 China

In-situ Al2O3/tiAl composites were fabricated by pressure-assisted exothermic dispersion （PAXD） method from elemental powder mixtures of ti, Al, tiO2, and Nb2O5. the microstructures and mechanical properties of the as-sintered composites are investigated. the results show that the as-sintered products consist of γ-tiAl, α2-ti3Al, Al2O3, and NbAl3 phases. Microstructure analysis indicates that Al2O3 particles tend to disperse on the grain boundaries. Application of a moderate pressure of 35 MPa at 1200℃ yields Al2O3/tiAl composites with fine Al2O3 reinforcement and a discontinuous network linking by Al2O3 particles. the aluminide component has a fine submicron γ ＋α2 lamellar microstructure. With increasing Nb2O5 content, Al2O3 particles are dispersed uniformly in the matrix. the hardness of the composites increases gradually, and the bending strength and fracture toughness of the composites reach to the maximum value, respectively.

关键词： Al2 O3/tiAl composites Microstructure Mechanical properties

Effect of Aluminum on FOX-7 Structure

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火炸药学报 2019年第3期42卷 223-231,I0001页

作者： Lemi türker Middle East technical University Department of Chemistry üniversiteler

the effect of aluminum on FOX-7 structure was considered. Density functional approach at the level of unrestricted B3LYP/6-311++G(d,p) level was adopted. the model considered 1-4 aluminum atoms per FOX-7 molecule. the results show that the molecular geometries as well as many molecular orbital characteristics of FOX-7 molecule are subjected multiplicity of the composites, FOX-7 + n Al ( n =1-4). In the case of n =1-2, some conformational changes occur. In the presence of three aluminum atoms, the quartet state of the composite is stable but in the doublet state, one of the N—O bonds ruptures. As for the n =4 case the singlet and triplet states are stable but in the quintet state one of the N—O bonds cleaves. As the number of aluminum atoms increases, the HOMO-LUMO energy gap decreases generally.

关键词： FOX-7 1,1-diamino-2,2-dinitroethylene DADNE explosives aluminum DFt