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A review of control strategies used for morphing aircraft applications

Chinese Journal of aeronautics 2024年第4期37卷 436-463页

作者： Muhammed S.PARANCHEERIVILAKKATHIL Jafar S.PILAKKADAN Rafic M.AJAJ Mohammadreza AMOOZGAR Davood ASADI Yahya ZWEIRI Michael I.FRISWELL department of Aerospace engineering Khalifa University of Science and TechnologyAbu DhabiUnited Arab Emirates department of Aerospace engineering Advanced Research and Innovation Center(ARIC)Khalifa University of Science and TechnologyAbu DhabiUnited Arab Emirates department of Mechanical Materials&Manufacturing EngineeringUniversity of NottinghamNottingham NG72RDUK department of Aerospace engineering Adana Alparslan Turkes Science and Technology UniversityTurkey College of engineering Swansea UniversitySwansea SA18ENUK

This paper reviews the various control algorithms and strategies used for fixed-wing morphing aircraft applications. It is evident from the literature that the development of control algorithms for morphing aircraft technologies focused on three main areas. The first area is related to precise control of the shape of morphing concepts for various flight conditions. The second area is mainly related to the flight dynamics, stability, and control aspects of morphing aircraft. The third area deals mainly with aeroelastic control using morphing concepts either for load alleviation purposes and/or to control the instability boundaries. The design of controllers for morphing aircraft/wings is very challenging due to the large changes that can occur in the structural, aerodynamic, and inertial characteristics. In addition, the type of actuation system and actuation rate/speed can have a significant effect on the design of such controllers. The aerospace community is in strong need of such a critical review especially as morphing aircraft technologies move from fundamental research at a low Technology Readiness Level(TRL) to real-life applications. This critical review aims to identify research gaps and propose future directions. In this paper, research activities/papers are categorized according to the control strategy used. This ranges from simple Proportional Integral Derivative(PID) controllers at one end to complex robust adaptive controllers and deep learning algorithms at the other end. This includes analytical, computational, and experimental studies. In addition, the various dynamic models used and their fidelities are highlighted and discussed.

关键词： Control strategies Morphing aircraft Shape morphing Flight dynamics Aeroelasticity

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Dual-functional poly(2-methyl-2-oxazoline)/poly(2-(dimethylamine)ethyl methacrylate)mixed brushes with switchable protein adsorption and antibacterial properties

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Chinese Journal of Chemical engineering 2024年第2期66卷 19-30页

作者： Kang He Liangyu Zhu Yanmei Wang CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China

Herein,binary mixed brushes consisting of poly(2-methyl-2-oxazoline)(PMOXA)and poly(2-(dimethylamine)ethyl methacrylate)(PDMAEMA)with different chain lengths were fabricated by successive grafting of NH_(2)-terminated PMOXA and SH-terminated PDMAEMA onto polydopamine-anchored *** mixed-brush coating was characterized by variable-angle spectroscopic ellipsometry,X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,zeta potential measurements,water contact angle,and atomic force *** mixed brushes showed tunable surface charge,wettability,and surface roughness,depending on the degree of PDMAEMA swelling under varying pH and ionic strength(Ⅰ).Then the adsorption behaviors of pepsin,bovine serum albumin(BSA),γ-globulin,and lysozyme,four very different proteins with regard to isoelectric point,on the mixed brushes coating were studied by using fluorescence microscopy and surface plasmon *** the chain length of PDMAEMA was about twice as long as PMOXA,the mixed brushes not only had high adsorption capacity for pepsin,BSA,and y-globulin but also had a desorption efficiency of 86.9%,87.1%,and 93.5%,*** is explained that electrostatic attraction between the protonated PDMAEMA and positively charged acidic proteins(pepsin and BSA,whose isoelectric points were below the pK_(a) of PDMAEMA)would drive the intensive adsorption(at pH 3,I=10^(-3)mol·L^(-1)for pepsin,and pH 5,I=10^(-5)mol·L^(-1)for BSA),while desorption was dominated by the hydrophilic PMOXA when PDMAEMA was shrinking(at pH 7,I=10^(-1)mol·L^(-1)for pepsin,and pH 9,I=10^(-1)mol·L^(-1)for BSA).Furthermore,the isoelectric precipitation led to the adsorption of neutral protein(γ-globulin,whose isoelectric point was near the pK_a of PDMAEMA)at pH 7,I=10^(-5)mol·L^(-1),while electrostatic repulsion and antifouling PMOXA triggered the desorption of y-globulin at pH 3,I-10^(-1)mol·L^(-1).However,alkaline protein(lysozyme,whose isoelectric point was higher than

关键词： Switchable conformation transition Controllable protein adsorption Mixed brushes Isoelectric point Antibacterial surface

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Monolithic integrated optoelectronic chip for vector force detection

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Microsystems & Nanoengineering 2024年第3期10卷 245-257页

作者： Jiansong Feng Zhongqi Wang Mengyuan Zhanghu Xu Zhang Yong Shen Jing Yang Zhibin Li Bin Chen Taihong Wang Xiaolong Chen Zhaojun Liu department of Electrical and Electronic engineering Southern University of Science and TechnologyShenzhen 518055China department of Electrical and Electronic engineering The University of Hong KongHong KongChina

Sensors with a small footprint and real-time detection capabilities are crucial in robotic surgery and smart wearable *** device footprint while maintaining its high performance is a major challenge and a significant limitation to their ***,we proposed a monolithic integrated micro-scale sensor,which can be used for vector force *** sensor combines an optical source,four photodetectors,and a hemispherical silicone elastomer component on the same sapphire-based AlGaInP *** chip-scale optical coupling is achieved by employing the laser lift-off techniques and the flip-chip bonding to a processed sapphire *** hemispherical structure device can detect normal and shear forces as low as 1mN within a measurement range of 0–220 mN for normal force and 0–15 mN for shear *** packaging,the sensor is capable of detecting forces over a broader range,with measurement capabilities extending up to 10 N for normal forces and 0.2 N for shear *** has an accuracy of detecting a minimum normal force of 25 mN and a minimum shear force of 20 ***,this sensor has been validated to have a compact footprint of approximately 1.5 mm^(2),while maintaining high real-time *** also demonstrate its promising potential by combining this sensor with fine surface texture perception in the fields of compact medical robot interaction and wearable devices.

关键词： robot force smart

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CToMP: a cycle-task-oriented memory protection scheme for unmanned systems

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science China(Information sciences) 2024年第6期67卷 399-417页

作者： Chengyan MA Ning XI Di LU Yebo FENG Jianfeng MA School of Cyber engineering Xidian University School of Computer science and Technology Xidian University department of Computer and Information science University of Oregon

Memory corruption attacks(MCAs) refer to malicious behaviors of system intruders that modify the contents of a memory location to disrupt the normal operation of computing systems, causing leakage of sensitive data or perturbations to ongoing processes. Unlike general-purpose systems, unmanned systems cannot deploy complete security protection schemes, due to their limitations in size, cost and *** in unmanned systems are particularly difficult to defend against. Furthermore, MCAs have diverse and unpredictable attack interfaces in unmanned systems, severely impacting digital and physical sectors. In this paper, we first generalize, model and taxonomize MCAs found in unmanned systems currently, laying the foundation for designing a portable and general defense approach. According to different attack mechanisms,we found that MCAs are mainly categorized into two types — return2libc and return2shellcode. To tackle return2libc attacks, we model the erratic operation of unmanned systems with cycles and then propose a cycle-task-oriented memory protection(CToMP) approach to protect control flows from tampering. To defend against return2shellcode attacks, we introduce a secure process stack with a randomized memory address by leveraging the memory pool to prevent Shellcode from being executed. Moreover, we discuss the mechanism by which CTo MP resists the return-oriented programming(ROP) attack, a novel variant of return2libc attacks. Finally, we implement CTo MP on CUAV V5+ with Ardupilot and Crazyflie. The evaluation and security analysis results demonstrate that the proposed approach CTo MP is resilient to various MCAs in unmanned systems with low footprints and system overhead.

关键词： unmanned system memory corruption attack memory protection system security randomized memory address

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A Comprehensive Study of a Low-Grade Heat-Driven Cooling and Power System Based on Heat Current Method

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Journal of Thermal science 2024年第4期33卷 1523-1541页

作者： ZHAO Tian XU Ronghong XIN Yonglin HE Kelun MA Huan YUAN Mengdi CHEN Qun School of Energy Storage science and engineering North China University of TechnologyBeijing100144China Key Laboratory for Thermal science and Power engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing100084China

Combined cooling and power(CCP)system driven by low-grade heat is promising for improving energy *** work proposes a CCP system that integrates a regenerative organic Rankine cycle(RORC)and an absorption chiller on both driving and cooling fluid *** system is modeled by using the heat current method to fully consider nonlinear heat transfer and heat-work conversion constraints and resolve its behavior *** off-design system simulation is performed next,showing that the fluid inlet temperatures and flow rates of cooling water as well as RORC working fluid strongly affect system *** off-design operation even becomes infeasible when parameters deviate from nominal values largely due to limited heat transfer capability of components,highlighting the importance of considering heat transfer constraints via heat current *** optimization aiming to minimize the total thermal conductance is also *** efficiency increases by 7.9%and decreases by 12.4%after optimization,with the hot fluid inlet temperature increase from 373.15 to 403.15 K and mass flow rate ranges from 10 to 30 kg/s,emphasizing the necessity of balancing system cost and performance.

关键词： combined cooling and power system organic Rankine cycle absorption chiller cascade heat utilization heat current method off-design analysis

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Characterization and Analysis of Inconel 718 Alloy Ground at Different Speeds

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Chinese Journal of Mechanical engineering 2024年第2期37卷 137-149页

作者： Hao Liu Huili Han Qinghong Jiang Minglin He Bi Zhang department of Mechanical and Energy engineering Southern University of Science and TechnologyShenzhen 518055China department of Mechanical engineering Hong Kong Polytechnic UniversityHong KongChina

Inconel 718(IN718)alloy is widely applied to fabricate high temperature resistant or corrosion resistant parts due to its excellent mechanical ***,the machining of IN718 alloy is difficult as it may cause serious tool wear and poor surface quality(SQ)of the *** this work,grinding experiments on IN718 alloy at different speeds were conducted by using a CBN grinding *** relationship between grinding speed,SQ and subsurface damage(SSD)was well *** increasing grinding speed,surface roughness decreased,and SQ was greatly ***,the microhardness of the grinding surface declined as the grinding speed *** SSD depth was almost unchanged when the grinding speed was lower than 15 m/s,then it decreased with higher grinding *** was attributed to the mechanical-thermal synergistic effect in the grinding *** results indicated that increasing grinding speed can effectively improve the SQ and reduce the SSD of IN718 *** conclusion in the work may also provide insight into processing other hard-to-machining materials.

关键词： Surface integrity Grinding speed IN718 alloy Precision machining CBN grinding wheel

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An Effective Approach for the Preparation of High Performance Thermal Conductive Polymer Composites Containing Liquid Metal

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Chinese Journal of Polymer science 2024年第7期42卷 992-1001,I0010页

作者： Xin Chen Xue-Zhong Zhang Yi-Fei Yuan Chuan-Liang Chen Lian-Hu Xiong Qiang Fu Hua Deng College of Polymer science and engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu610065China department of Materials science and engineering Sichuan University-Pittsburgh InstituteSichuan UniversityChengdu610065China

The preparation of high-performance thermal conductive composites containing liquid metals(LM)has attracted significant ***,the stable dispersion of LM within polymer solution and effective property contribution of liquid metals remains significant challenges that need to be *** by the properties of the dendritic structure of the tree root system in grasping the soil,“shear-induced precipitation-interfacial reset-reprotonation”processing strategy is proposed to prepare nanocomposites based on aramid micron fibers(AMFs)with hierarchical dendritic *** to the combination of van der Waals force provided by hierarchical dendritic structure,electrostatic interaction between AMFs and LM,coordinative bonding of―NH to LM,together with interfacial re-setting and multi-step protonation,several features can be achieved through such strategy:conducive to the local filler network construction,improvement of interfacial interaction,improvement of the stability of filler dispersion in the solvent,and enhancement of mechanical and thermal properties of the *** resulting AMFsp H=4/LM films demonstrate a thermal conductivity of 10.98 W·m^(-1)·K^(-1)at 70%filler content,improvement of 126.8%compared to ANFs/LM film;while maintaining a strength of~85.88 MPa,improvement of 77%compared to AMFs/LM *** also possess insulation properties,enable heat dissipation for high power *** work provides an effective strategy for the preparation of high performance polymer composites containing liquid metal.

关键词： Shear-induced Reprotonation AMFs LM Filler dispersion

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Anticipating the lifespan: Predicting the durability of an anode-supported solid oxide fuel cell short stack over 50,000 h

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Progress in Natural science:Materials International 2024年第3期34卷 606-613页

作者： Muhammad Zubair Khan Amjad Hussain Seung-Bok Lee Tak-Hyoung Lim Rak-Hyun Song department of Materials science & engineering Pak-Austria Fachhochschule: Institute of Applied Sciences and Technology Hydrogen Energy Research Division Korea Institute of Energy Research department of Advanced Energy and System engineering Korea University of Science and Technology (UST)

In the present study, the operational lifetime of a solid oxide fuel(SOFC) short stack is predicted by investigating the performance degradation of both the short stack and its cells throughout 1000 h at 800°C. The short stack and integral cell voltages are continuously measured during the long-term test, with electrochemical impedance spectroscopy(EIS) conducted every 200 h. The short stack voltage decreased rapidly for the initial 200–300 h and afterwards, it decreased at a slow rate due to the increase in the Ohmic and polarization resistances in the same manner. Scanning electron microscopy results show that there is no delamination or cracking among constituent layers of the short-stack cells. The single degradation effects of the Ni coarsening in the anode, cation migration and surface segregation in cathode and oxide scale growth in metallic interconnect mesh are successfully integrated into a comprehensive lifetime prediction model. The experimentally measured voltage degradation data of the short stack fits well with the developed mathematical model and allows the successful prediction of the lifetime up to 50,000 h.

关键词： Degradation Impedance Lifetime SOFC Stack

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Thermal Decomposition and Oxidative Decomposition Mechanism of HFC-134a by Experimental and DFT Method

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Journal of Thermal science 2024年第5期33卷 1990-2003页

作者： XU Yunting ZHANG Kai DAI Xiaoye SHI Lin Key Laboratory for Thermal science and Power engineering of Ministry of Education Department of Energy and Power EngineeringTsinghua UniversityBeijing 100084China

In response to the Kigali Amendment to the Montreal Protocol and global low-carbon emission environmental requirements,the phase-out and decomposition of numerous HFC refrigerants have become urgent,necessitating efficient and mild decomposition *** study investigates the thermal decomposition and oxidative thermal decomposition pathways of the typical hydrofluorocarbon refrigerant HFC-134a,employing a combination of experimental and quantum chemical DFT simulation *** chemical simulations reveal that the initial reaction bond cleavage serves as the rate-determining step during the thermal decomposition process,with the most easily detectable closed-shell products including CF_(2)=CHF,HF,CH_(3)F,CHF_(3),CH_(2)F_(2),and CF_(4).Reactive oxygen species can significantly reduce the Gibbs free energy barrier for HFC-134a *** achieve efficient degradation of HFC-134a,appropriate catalysts should be developed and selected to increase the level of reactive oxygen species in the reaction *** studies further corroborate that HFC-134a may undergo degradation through distinct reaction pathways under varying temperature(240℃to360℃)and pressure(0.1 MPa to 4.5 MPa)conditions,in agreement with simulation predictions.

关键词： HFC-134a pyrolysis oxidative thermal decomposition DFT refrigerant

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Continuously non-malleable codes from block ciphers in split-state model

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Cybersecurity 2024年第2期7卷 68-80页

作者： Anit Kumar Ghosal Dipanwita Roychowdhury department of Computer science and engineering I KharagpurKharagpurWest BengalIndia

Non-malleable code is an encoding scheme that is useful in situations where traditional error correction or detection is impossible to *** ensures with high probability that decoded message is either completely unrelated or the original one,when tampering has no ***,standard version of non-malleable codes provide security against one time tampering *** ciphers are successfully employed in the construction of non-malleable *** construction fails to provide security when an adversary tampers the codeword more than *** non-malleable codes further allow an attacker to tamper the message for polynomial number of *** this work,we propose continuous version of non-malleable codes from block ciphers in split-state *** construction provides security against polynomial number of tampering attacks and it preserves *** the tam-pering experiment triggers self-destruct,the security of continuously non-malleable code reduces to security of the underlying leakage resilient storage.

关键词： Block cipher Non-malleable code Split-state model Tamper-resilient cryptography

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