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Two‑Dimensional Cr_(5)Te_(8)@Graphite Heterostructure for Efficient Electromagnetic Microwave Absorption

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Nano-Micro Letters 2024年第3期16卷 407-422页

作者： Liyuan Qin Ziyang guo Shuai zhao Denan Kong wei Jiang Ruibin Liu Xijuan Lv Jiadong Zhou Qinghai Shu School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081People’s Republic of China Centre for Quantum Physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE)School of PhysicsBeijing Institute of TechnologyBeijing 100081People’s Republic of China Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081People’s Republic of China Tangshan Research Institute Beijing Institute of TechnologyTangshan 063099People’s Republic of China

Two-dimensional(2D)transition metal chalcogenides(TMCs)hold great promise as novel microwave absorption materials owing to their interlayer interactions and unique magnetoelectric ***,overcoming the impedance mismatch at the low loading is still a challenge for TMCs due to the restricted loss pathways caused by their high-density ***,an interface engineering based on the heterostructure of 2D Cr_(5)Te_(8) and graphite is in situ constructed via a one-step chemical vapor deposit to modulate impedance matching and introduce multiple attenuation ***,the Cr_(5)Te_(8)@EG(ECT)heterostructure exhibits a minimum reflection loss of up to−57.6 dB at 15.4 GHz with a thin thickness of only 1.4 mm under a low filling rate of 10%.The density functional theory calculations confirm that the splendid performance of ECT heterostructure primarily derives from charge redistribution at the abundant intimate interfaces,thereby reinforcing interfacial polarization ***,the ECT coating displays a remarkable radar cross section reduction of 31.9 dB m^(2),demonstrating a great radar microwave scattering *** work sheds light on the interfacial coupled stimulus response mechanism of TMC-based heterogeneous structures and provides a feasible strategy to manipulate high-quality TMCs for excellent microwave absorbers.

关键词： Chemical vapor deposition Interface polarization engineering Cr_(5)Te_(8)-graphite heterojunctions Microwave absorption

Design of digital calibration based on variable step size of sub-binary SAR ADC

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The Journal of China Universities of Posts and Telecommunications 2024年第2期31卷 62-71页

作者： Liu wei zhao Yanke Shang Shiguang School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi'an 710121China

Addressing the impact of capacitor mismatch on the conversion accuracy of successive approximation register analog-to-digital converter(SAR ADC),a 12-bit 1 MS/s sub-binary SAR ADC designed using variable step size digital calibration was *** least mean square(LMS)calibration algorithm was employed with a ramp signal used as the calibration *** errors,extracted under injected disturbances,underwent iterative training to optimize weight *** address the trade-off between conversion accuracy and speed caused by a fixed step size,a novel variable step size algorithm tailored for SAR ADC calibration was *** core circuit and layout of the SAR ADC were implemented using the Taiwan Semiconductor Manufacturing Company(TSMC)0.35μm complementary metal-oxide-semiconductor(CMOS)commercial *** of the SAR ADC calibration algorithm was conducted using Simulink,demonstrating quick convergence and meeting conversion accuracy requirements compared to fixed step size *** results indicated that the convergence speed of the LMS digital calibration algorithm with variable step size was approximately eight times faster than that with a fixed step size,also yielding a lower mean square error(MSE).After calibration,the simulation results for the SAR ADC exhibited an effective number of bit(ENOB)of 11.79 bit and a signal-to-noise and distortion ratio(SNDR)of 72.72 dB,signifying a notable enhancement in the SAR ADC performance.

关键词： successive approximation register analog-to-digital converter(SAR ADC) variable step size digital calibration disturbance technique

Disturbance Observer-Based Predictive Tracking Control of Uncertain HOFA Cyber-Physical Systems

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1711-1713页

作者： Da-wei Zhang guo-Ping Liu IEEE the Center for Control Theory and Guidance Technology Harbin Institute of TechnologyHarbin 150001China the Center for Control Science and Technology Southern University of Science and TechnologyShenzhen 518055China

Dear Editor,In this letter,an output tracking control problem of uncertain cyber-physical systems(CPSs)is considered in the perspective of high-order fully actuated(HOFA)system theory,where a lumped disturbance is use... 详细信息

关键词： Observer Uncertain letter

Robust textile-based spoof plasmonic frequency scanning antenna for on-body IoT applications

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Science China(Information Sciences) 2024年第8期67卷 269-284页

作者： zhao-Min CHEN Jun-Lin ZHAN Hao CHEN Ya LI Hongjun HE Wu YANG Zhen-guo LIU wei-Bing LU State Key Lab of Millimeter Waves School of Information Science and EngineeringSoutheast University Center for Flexible RF Technology Frontiers Science Center for Mobile Information Communication and SecuritySoutheast University Future Research Laboratory China Mobile Research Institute Purple Mountain Laboratories

Securing a comfortable, wearable compact frequency beam scanning antenna(FBSA) with robustness to deformation, low specific absorption rate(SAR), and good coverage of the surrounding environment for Internet of Things(IoT) applications, such as on-body navigation and wireless communication is an emerging challenge. In this work, a robust textile-based spoof plasmonic frequency scanning antenna utilizing higher-order modes is presented, which is also robust to deformation caused by the activities of the human body. The innovative design of the element ensures the high-efficiency transmission of the fundamental mode of spoof surface plasmon polaritons(SSPP) structure, providing the potential of being a multifunctional composite device in the compact on-body network. Besides, an artificial magnetic conductor(AMC) is designed underneath the SSPP structure, obtaining a low SAR value(0.113 W/kg), which ensures the safety of users. As a practical realization of this concept, a textile-based spoof plasmonic antenna was fabricated in the microwave regime and the performed experimental results show the proposed antenna has a single-beam radiation characteristic with a 70° beam scanning angle range when the frequency is 4.7–6.0 GHz with a high average realized gain of 13.15 dBi. And it still maintains a steady performance when faced with structure deformation, which proves its robustness. Wireless communication quality experiments are performed to demonstrate the proposed antenna can measure the angles of targets and realize wireless signal transmission to specific targets as the frequency varies, it may find great potential in the field of on-body IoT applications.

关键词： frequency beam scanning antenna (FBSA) Internet of Things (IoT) on-body communication spoof surface plasmon polaritons (SSPP) textile-based antenna

Light-induced stepped thermal relaxation in a Hofmann-type metal-organic framework

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Science China Chemistry 2024年第6期67卷 1983-1989页

作者： Wen Cui wei-wei Wu Ze-Yu Ruan Yan-Cong Chen Guang-Jun Zeng Guan-Xi Chen Si-guo Wu zhao-Ping Ni Ming-Liang Tong Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education School of ChemistryInstitute of Green Chemistry and Molecular EngineeringGuangdong Basic Research Center of Excellence for Functional Molecular EngineeringSun Yat-sen UniversityGuangzhou510275China

Spin-crossover(SCO)materials with light-induced multistability have potential applications in multi-addressable opto-magnetic memory devices and multiple ***,we reported a three-dimensional Hofmann-type metal-organic framework(MOF)[Fe(bpy){Pt(CN)_(4)}]·coumarin(1·coumarin,bpy=4,4′-bipyridine),which exhibits an incomplete and hysteretic SCO *** importantly,the light-induced stepped thermal relaxation(LISTR)with obvious magnetic plateau for a hidden intermediate spin state is firstly *** hidden spin state is also observed for the first time in the thermal relaxation after light-assisted spin state annealing(LASSA).Meanwhile,an extremely rare bi-directional light-induced excited spin-state trapping(LIESST)with the highest reverse-LIESST temperature is ***,five spin states can be captured in 1·coumarin and the tristability can be modulated below 102 K through the excitation-relaxation ***,the light-and temperatureinduced multistability provides a new strategy for developing multistable materials.

关键词： light magnetic multistability iron metal-organic framework spin-crossover

Effects of ulinastatin combined with dexmedetomidine on cognitive dysfunction and emergence agitation in elderly patients who underwent total hip arthroplasty

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World Journal of Psychiatry 2024年第1期14卷 26-35页

作者： Qi-Fan Huo Li-Juan Zhu Jian-wei guo Yan-An Jiang Jing zhao Department of Anesthesiology Shaanxi Provincial People’s HospitalXi’an 710068Shaanxi ProvinceChina

BACKGROUND With the continuous growth of the modern elderly population,the risk of fracture *** fracture is a common type of fracture in older *** hip arthroplasty(THA)has significant advantages in relieving chronic pain and promoting the recovery of hip joint *** To investigate the effect of ulinastatin combined with dexmedetomidine(Dex)on the incidences of postoperative cognitive dysfunction(POCD)and emergence agitation in elderly patients who underwent *** A total of 397 patients who underwent THA from February 2019 to August *** conducted a three-year retrospective cohort study in Shaanxi Provincial People’s *** demographic data were obtained from the electronic medical record *** collected preoperative,intraoperative,and postoperative *** hundred twenty-nine patients who were administered Dex during the operation were included in the Dex *** hundred fifty patients who were intravenously injected with ulinastatin 15 min before anesthesia induction were included in the ulinastatin *** hundred eighteen patients who were administered ulinastatin combined with Dex during the operation were included in the Dex+ulinastatin *** patients’perioperative conditions,hemodynamic indexes,postoperative Mini-Mental State Examination(MMSE)scores,Ramsay score,incidence of POCD,and serum inflammatory cytokines were *** There was a significant difference in the 24 h visual analogue scale score among the three groups,and the score in the Dex+ulinastatin group was the lowest(P<0.05).Compared with the Dex and ulinastatin group,the MMSE scores of the Dex+ulinastatin group were significantly increased at 1 and 7 d after the operation(all P<0.05).Compared with those in the Dex and ulinastatin groups,incidence of POCD,levels of serum inflammatory cytokines in the Dex+ulinastatin group were significantly decreased at 1 and 7 d after the operation(all P<0.05).The observer’s assessment of th

关键词： Ulinastatin Dexmedetomidine Postoperative cognitive dysfunction Inflammatory cytokines Total hip arthroplasty

Simulation of nanofluid natural convection based on single-particle hydrodynamics in energy-conserving dissipative particle dynamics(eDPD)

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1429-1446页

作者： wei LU Shuo CHEN Zhiyuan YU Jiayi zhao School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092China Shanghai Key Laboratory of Vehicle Aerodynamics and Vehicle Thermal Management Systems Tongji UniversityShanghai 201804China School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China

In the present study,the nanofliud natural convection is investigated by the energy-conserving dissipative particle dynamics(eDPD)method,where the nanoparticles are considered at the single-particle *** thermal expansion coefficientβand the viscosityμof the simulated system containing nanoparticles are calculated and found to be in close alignment with the previous simulation *** single-particle hydrodynamics in e DPD enables simulations of nanofluid natural convection with higher Rayleigh numbers and greater nanoparticle volume ***,this approach is utilized to simulate the nanoparticle distribution during the enhanced heat transfer process in the nanofluid natural *** localized aggregation of nanoparticles enhances the heat transfer performance of the nanofluid under specific Rayleigh numbers and nanoparticles volume fractions.

关键词： single-particle hydrodynamics energy-conserving dissipative particle dynamics(eDPD) nanoparticle nanofluid heat transfer

Accelerating Asteroidal Period and Pole Inversion from Multiple Lightcurves Using Parallel Differential Evolution and Cellinoid Shape Model

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Research in Astronomy and Astrophysics 2024年第4期24卷 271-286页

作者： Yong-Xiong Zhang Wen-Xiu guo Xiao-Ping Lu Hua Zheng Hai-Bin zhao Jun Tian wei-Lin Wang School of Engineering Guangzhou College of Technology and BusinessGuangzhou 510850China School of Computer Science and Engineering Macao University of Science and TechnologyTaipaMacao 999078China School of Mathematics and Statistics Shaoguan UniversityShaoguan 512099China State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyMacao 999078China Key Laboratory of Planetary Sciences Purple Mountain ObservatoryCASNanjing 210023China

Determining asteroid properties provides valuable physical insights but inverting them from photometric lightcurves remains computationally *** paper presents a new approach that combines a simplified Cellinoid shape model with the Parallel Differential Evolution(PDE)algorithm to accelerate *** PDE algorithm is more efficient than the Differential Evolution algorithm,achieving an extraordinary speedup of 37.983 with 64 workers on multicore *** PDE algorithm accurately derives period and pole values from simulated *** analysis of real asteroid lightcurves validates the method’s reliability:in comparison with results published elsewhere,the PDE algorithm accurately recovers the rotational periods and,given adequate viewing geometries,closely matches the pole *** PDE approach converges to solutions within 20,000 iterations and under one hour,demonstrating its potential for large-scale data *** work provides a promising new tool for unveiling asteroid physical properties by overcoming key computational bottlenecks.

关键词： methods:numerical minor planets asteroids:general techniques:photometric astrom

Tailoring of a robust asymmetric aramid nanofibers/MXene aerogel film for enhanced infrared thermal camouflage and Joule heating performances

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Nano Research 2024年第3期17卷 1990-1998页

作者： Wanbin Dang wei guo Wenting Chen Qiuyu Zhang Key Laboratory of Special Functional and Smart Polymer Materials of Ministry of Industry and Information Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China

The development of infrared(IR)surveillance technology has led to a growing interest in thermal ***,the trade-off relationship between low IR-emissivity and thermal insulation hinders the advance of thermal camouflage ***,guided by multi-physics simulation,we show a design of asymmetric aramid nanofibers/MXene(ANF/MXene)aerogel film that realizes high-efficient thermal camouflage *** rationale is that the asymmetric structure contains a thermal-insulation three-dimensional(3D)network part to prevent effective heat transfer and a low IR-emissivity(~0.3)dense surface layer to suppress radiative heat *** is remarkable that the synergy mechanism in the topology structure contributes to over 40%reduction of target radiation ***,the tailored asymmetric ANF/MXene aerogel film also enables sound mechanical properties such as a Young’s modulus of 44.4 MPa and a tensile strength of 1.3 MPa,superior to most aerogel *** also exhibits great Joule heating performances including low driving voltage(4 V),fast thermal response(<10 s),and long-term stability,further enabling its versatile thermal camouflage *** work offers an innovative design concept to configure multifunctional structures for next-generation thermal management applications.

关键词： asymmetric aerogel film low infrared(IR)-emissivity thermal insulation IR thermal camouflage Joule heating performance