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Defence Technology（防务技术） 2024年第3期33卷 66-77页

作者： Tihomir Kovacevic Slavko Mijatov Jelena Grzetic Suzana Cakic Bojana Fidanovski Sasa Brzic Military technical Institute Ministry of DefenceRatka Resanovica 1BelgradeSerbia Faculty of Technology University of NisBulevar osloboCenja 124LeskovacSerbia

Conventional plasticizers deteriorate mechanical and viscoelastic properties of the propellants due to their migration upon aging and long-term storage,which affects reliability and safety properties during *** address this issue,conventional plasticizer,dioctyl adipate(DOA),is replaced by reactive one,castor oil(CO).In addition,three different types of HTPB were used to obtain propellants with designed viscoelastic and mechanical *** CO increased propellants viscosity,without a significant impact on the propellant processability,regardless to the type of ***,mechanical properties were different depending on the type of resin,which were further analyzed by gel permeation chromatography(GPC).Addition of CO formed a denser polymer network and shifted T_(g) to higher values,compared to the compositions with *** tensile strength of CO-containing propellants was lower at +20℃ and +50℃ compared to the reference compositions,while the strain at maximum load and strain at break were significantly increased with pronounced plastic deformation,especially for samples at -30℃.The inclusion of CO in the propellants composition gives more room for adjusting a wide range of mechanical properties.

关键词： HTPB-based composite propellants Castor oil Reactive plasticizer Gel permeation chromatography Sol-gel analysis Mechanical and viscoelastic properties

Study of relationship between motion of mechanisms in gas operated weapon and its shock absorber

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Defence Technology（防务技术） 2024年第3期33卷 42-54页

作者： Jiri Balla Roman Vitek Dung Nguyen Van Zbynek Krist Hung Nguyen Van Department of Weapons and Ammunition University of Defence BrnoCzech Republic Department of Weapons Le Quy Don Technical UniversityHanoiViet Nam Department of Design and Special Engineering Alexander Dubcek University of TrencinSlovakia

The article deals with the motion of the breech block carrier and the weapon casing of an automatic weapon mounted on a flexible carriage and the base of the *** works,which did not consider the dynamic properties of the base of the weapon,did not allow to reconcile the calculated and experimental results of the weapon casing displacement when shooting from firing *** the analysis of the motion of individual parts,the methods of mathematical modelling and firing experiments using a high-speed camera were *** show the best accord with experiment when modelling the system with 4 degrees of *** oscillation of the system regarding the movement of the breech block carrier and the weapon casing was investigated under changed conditions of rate of fire,the use of a muzzle brake and different types of shock *** velocities and displacements of the weapon casing and the breech block carrier at different values of the impulse of the gases to the breech block carrier were determined.

关键词： Shock absorber Gas-operated weapon Force-impulse diagram Recoil system Breech block carrier

Wireless Power Supply Based on MNG-MNZ Metamaterial for Cardiac Pacemakers

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CES Transactions on Electrical Machines and Systems 2024年第1期8卷 103-112页

作者： Weihua Chen Jingtao Jia Xiaoheng Yan Yuhang Song Jiayi Li Faculty of Electrical and Control Engineering Liaoning Technical UniversityNo.188Longwan South StreetXingchengHuludao 125105China CES

To solve the low power transfer efficiency and magnetic field leakage problems of cardiac pacemaker wireless powering, we proposed a wireless power supply system suitable for implanted cardiac pacemaker based on mu-negative(MNG) and mu-nearzero(MNZ) metamaterials. First, a hybrid metamaterial consisted of central MNG unit for magnetic field concentration and surrounding MNZ units for magnetic leakage shielding was established by theoretical calculation. Afterwards, the magnetic field distribution of wireless power supply system with MNG-MNZ metamaterial slab was acquired via finite element simulation and verified to be better than the distribution with conventional MNG slab deployed. Finally, an experimental platform of wireless power supply system was established with which power transfer experiment and system temperature rise experiment were *** and experimental results showed that the power transfer efficiency was improved from 44.44%,19.42%, 8.63% and 6.19% to 55.77%, 62.39%, 20.81%and 14.52% at 9.6 mm, 20 mm, 30 mm and 50 mm,respectively. The maximum SAR acquired by SAR simulation under human body environment was-7.14 dbm and maximum reduction of the magnetic field strength around the receiving coil was 2.82 A/m. The maximum temperature rise during 30min charging test was 3.85℃,and the safety requirements of human bodies were met.

关键词： Cardiac pacemaker MNG metamaterial MNZ metamaterial Wireless power supply system

Passive particles driven by self-propelled particle:The wake effect

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Chinese Physics B 2024年第4期33卷 500-507页

作者：郑凯选汪静文王世锋聂德明 Institute of Fluid Mechanics China Jiliang UniversityHangzhou 310018China Department of Mechanical Engineering Hangzhou Vocational&Technical CollegeHangzhou 310018China

This work focuses on numerically studying hydrodynamic interaction between a passive particle and a self-propelled particle,termed a squirmer,by using a two-dimensional lattice Boltzmann method(LBM).It is found that the squirmer can capture a passive particle and propel it simultaneously,provided the passive particle is situated within the squirmer's *** research shows that the critical capture distance,which determines whether the particle is captured,primarily depends on the intensity of the squirmer's *** stronger dipolarity of squirmer results in an increased critical capture ***,the Reynolds number is found to have minimal influence on this ***,the passive particle,when driven by the squirmer's wake,contributes to a reduction in the squirmer's *** results in a mutual acceleration for both *** findings can provide valuable perspectives for formulating the principles of reducing the drag of micro-swimmers and help to achieve the goal of using micro-swimmers to transport goods without physical tethers.

关键词： lattice Boltzmann method(LBM) self-propelled particles particle-laden flow

Electrically tunable third-harmonic generation using intersubband polaritonic metasurfaces

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Light(Science & Applications) 2024年第8期13卷 1666-1674页

作者： Seongjin Park Jaeyeon Yu Gerhard Boehm Mikhail A.Belkin Jongwon Lee Department of Electrical Engineering Ulsan National Institute of Science and Technology(UNIST)UlsanRepublic of Korea Walter Schottky Institute Technical University of MunichGarchingGermany

Nonlinear intersubband polaritonic metasurfaces,which integrate giant nonlinear responses derived from intersubband transitions of multiple quantum wells(MQWs)with plasmonic nanoresonators,not only facilitate efficient frequency conversion at pump intensities on the order of few tens of kW cm^(-2)but also enable electrical modulation of nonlinear responses at the individual meta-atom level and dynamic beam *** electrical modulation characteristics of the magnitude and phase of the nonlinear optical response are realized through Stark tuning of the resonant intersubband *** this study,we report,for the first time,experimental implementations of electrical modulation characteristics of mid-infrared third-harmonic generation(THG)using an intersubband polaritonic metasurface based on MQW with electrically tunable third-order nonlinear ***,we achieved a 450%modulation depth of the THG signal,86%suppression of zero-order THG diffraction tuning based on local phase tuning exceeding 180 degrees,and THG beam steering using phase *** work proposes a new route for electrically tunable flat nonlinear optical elements with versatile functionalities.

关键词： tunable tuning pump

Transient Stability Analysis of Grid-connected Converters in Wind Turbine Systems Based on Linear Lyapunov Function and Reverse-time Trajectory

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 782-790页

作者： Mohammad Kazem Bakhshizadeh Sujay Ghosh Guangya Yang Łukasz Kocewiak Ørsted Wind Power A/S Nesa Allé12820Denmark technical university of Denmark Anker Engelunds Vej 12800Denmark

As the proportion of converter-interfaced renewable energy resources in the power system is increasing,the strength of the power grid at the connection point of wind turbine generators(WTGs)is gradually *** research has shown that when connected with the weak grid,the stability of the traditional grid-following controlled converters will deteriorate,and they are prone to unstable phenomena such as *** to the limitations of linear analysis that cannot sufficiently capture the stability phenomena,transient stability must be *** far,standalone time-domain simulations or analytical Lyapunov stability criteria have been used to investigate transient ***,the time-domain simulations have proven to be computationally too heavy,while analytical methods are difficult to formulate for larger systems,require many modelling assumptions,and are often conservative in estimating the stability *** paper proposes and demonstrates an innovative approach to estimating the transient stability boundary via combining the linear Lyapunov function and the reverse-time trajectory *** proposed methodology eliminates the need of time-consuming simulations and the conservative nature of Lyapunov *** study brings out the clear distinction between the stability boundaries with different post-fault active current ramp rate *** the same time,it provides a new perspective on critical clearing time for wind turbine *** stability boundary is verified using time-domain simulation studies.

关键词： Lyapunov direct method non-autonomous system phase-locked loop(PLL) time trajectory reversal transient stability assessment wind turbine converter system

A Golden Touch in the Design of Multifunctional Porphyrin Metallacages:Host-Guest Chemistry for Drug-Target Interactions

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CCS Chemistry 2024年第7期6卷 1662-1671页

作者： Tamara Rodríguez-Prieto Darren Wragg Nicole Heiduk Mihyun Park Nicole Strittmatter Roland A.Fischer Angela Casini Guillermo Moreno-Alcántar Chair of Medicinal and Bioinorganic Chemistry Department of ChemistrySchool of Natural SciencesTechnical University of Munich85748 Garching b.München Professorship for Analytical Chemistry Department of ChemistrySchool of Natural SciencesTechnical University of Munich85748 Garching b.München Chair of Inorganic and MetalOrganic Chemistry Department of ChemistrySchool of Natural SciencesTechnical University of Munich85748 Garching b.München Munich Data Science Institute(MDSI) Technical University of Munich85748 Garching b.München

The use of three-dimensional self-assembled metallacages(MCgs)as multimodal drug platforms holds great ***,the synthesis of MCgs with increased complexity and functionality is a great challenge since understanding of the interaction of MCgs with biological targets is still *** this context,this work reports on the integration of a gold(III)porphyrin scaffold into a prismatic MCg structure and explores its application for multimodal therapy of cancer in vitro,namely enabling both photodynamic therapy and *** experimental approaches with a state-of-the-art metadynamics theoretical study,we discovered that the gold cage shows unprecedented host-guest interaction-driven selective stabilization of guanine-quadruplex(G4)structures-validated anticancer drug targets-disclosing a new mechanism to pursue in the design of supramolecular drugs.

关键词： gold metallacages porphyrins G4stabili-zation host-guestchemistry anticanceragents

Porous garnet as filler of solid polymer electrolytes to enhance the performance of solid-state lithium batteries

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Nano Research 2024年第4期17卷 2663-2670页

作者： Yang Zhang Lei Zhang Peng Guo Chaoyan Zhang Xiaochuan Ren Zhen Jiang Jianjun Song Chuan Shi College of Physics Qingdao UniversityQingdao 266071China Industrial Research Institute of Nonwovens and technical Textiles College of Textiles and ClothingQingdao UniversityQingdao 266071China Department of Chemistry University of PennsylvaniaPhiladelphiaPA 19104USA

In order to enhance the ionic conductivity of solid polymer electrolytes(SPEs)and their structural rigidity against lithium dendrite during lithium-ion battery(LIB)cycling,we propose porous garnet Li6.4La3Zr2Al0.2O12(LLZO),as the filler to *** porous LLZO with interlinked grains was synthesized via a resol-assisted cationic coordinative co-assembly *** porous structure of LLZO with high specific surface area facilitates the interaction between polymer and filler and provides sufficient entrance for Li^(+)migration into the LLZO ***,the interconnection of LLZO grains forms continuous inorganic pathways for fast Li^(+)migration,which avoid the multiple diffusion for Li^(+)in *** a result,the SPEs with porous LLZO(SPE-PL)show a high ionic conductive of 0.73 mS·cm^(-1) at 30℃ and lithium-ion transference number of *** porous LLZO with uniformly dispersed pores also acts as an ion distributor to regulate ionic *** lithium-symmetrical batteries assembled with SPE-PL show a highly stable Li plating/stripping cycling for nearly 3000 h at 0.1 mA·cm^(-2).The corresponding Li/LiFePO_(4) batteries also exhibit excellent cyclic performance with capacity retention of 75%after nearly 500 *** work brings new insights into the design of conductive fillers and the optimization of SPEs.

关键词： solid polymer electrolytes lithium metal battery porous conductive filler solid state battery

Cooperative THz communication for UAVs in 6G and beyond

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Green Energy and Intelligent Transportation 2024年第1期3卷 25-31页

作者： Nazifa Mustari Muhammet Ali Karabulut A.F.M.Shahen Shah Ufuk Tureli Department of Electronics and Communication Engineering Yildiz Technical UniversityTurkey Department of Electrical Electronics Engineering Faculty of Engineering and ArchitectureKafkas UniversityKarsTurkey

One of the key components of any smart city is considered to be its intelligent transportation systems(ITSs).Unmanned aerial vehicles(UAVs)are envisioned in several ITS application fields because of their autonomous operation,mobility,communication/processing capabilities,and other *** this paper,cooperative terahertz(THz)communication is proposed for flying ad hoc networks(FANETs),which is a particular kind of network made up of a collection of small UAVs linked in an ad hoc fashion and working together to accomplish high-level *** frequency spectrum for wireless communication has been expanding continuously in order to meet the demand for *** the forthcoming 6G and beyond,communications in the THz range will be vital,similar to how mmWave-band communications are currently influencing the 5G of wireless mobile *** finite state machine(FSM)of the proposed cooperative communication system for THz band is presented.A Markov chain model-based analytical study is carried out,which derives relationships among ***,numerical results are provided to support the analytical study.

关键词： Cooperative MAC THz UAVs 6G

Assessment of the implementation status of best available techniques for cleaner production in the textile industry

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Frontiers of Environmental Science & Engineering 2024年第8期18卷 133-148页

作者： Mehmet Eren Yaman Emrah Ozturk Ulku Yetis Mehmet Kitis Department of Environmental Engineering Suleyman Demirel UniversityIsparta 32260Turkey Department of Environmental Protection Technologies Isparta University of Applied SciencesIsparta 32200Turkey Department of Environmental Engineering Middle East Technical UniversityAnkara 06800Turkey

The draft Integrated Pollution Prevention and Control(IPPC)regulation mandates compliance with best available techniques(BATs)for textile manufacturers.A study in Turkish textile facilities,covering 56 units across four sub-sectors,assessed the status of 488 BATs through on-site visits and *** aim was to gauge the sector’s adherence to *** findings revealed that 37% of surveyed BATs were fully implemented,rising to 88% when considering potential future *** suggests a strong industry inclination toward adopting BATs for cleaner production and *** study highlighted significant BAT-related investments in the textile sector,driven by environmental concerns,regulations,customer demands,resource efficiency,competition,and cost-benefit ***,the study results also indicated that there is still much work to do for the implementation of some *** was found that 60 BATs had lower implementation ratios(IR:0%-43%).Lower IR values for these BATs are mainly due to factors like specificity,high costs,long payback periods,operational difficulties,limited expertise,space constraints,customer requirements,quality concerns,operational issues,and sector-specific *** study recommends similar assessments in other European industrial sectors to evaluate compliance with mandatory BATs outlined in the Industrial Emissions *** insights from this study on the Turkish textile sector can serve as a valuable guide for future evaluations.

关键词： Best available techniques(BAT) Cleaner production Green Deal Integrated Pollution Prevention and Control(IPPC) Textile sector