Exploring high-efficiency and broadband microwave absorption(MA)materials with corrosion resistance and low cost is ur-gently needed for wide practical ***,the natural porous attapulgite(ATP)nanorods embedded with TiO...
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Exploring high-efficiency and broadband microwave absorption(MA)materials with corrosion resistance and low cost is ur-gently needed for wide practical ***,the natural porous attapulgite(ATP)nanorods embedded with TiO_(2)and polyaniline(PANI)nanoparticles are synthesized via heterogeneous precipitation and in-situ *** obtained PANI-TiO_(2)-ATP one-di-mensional(1D)nanostructures can intertwine into three-dimensional(3D)conductive network,which favors energy *** min-imum reflection loss(RL_(min))of the PANI-TiO_(2)-ATP coating(20wt%)reaches-49.36 dB at 9.53 GHz,and the effective absorption band-width(EAB)can reach 6.53 GHz with a thickness of 2.1 *** excellent MA properties are attributed to interfacial polarization,mul-tiple loss mechanisms,and good impedance matching induced by the synergistic effect of PANI-TiO_(2)nanoparticle shells and ATP *** addition,salt spray and Tafel polarization curve tests reveal that the PANI-TiO_(2)-ATP coating shows outstanding corrosion resist-ance *** study provides a low-cost and high-efficiency strategy for constructing 1D nanonetwork composites for MA and corrosion resistance applications using natural porous ATP nanorods as carriers.
As a novel 2D material,Ti_(3)C_(2)T_(x)-MXene has become a major area of interest in the field of microwave absorption(MA).However,the MA effect of common Ti_(3)C_(2)T_(x)-MXene is not prominent and often requires com...
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As a novel 2D material,Ti_(3)C_(2)T_(x)-MXene has become a major area of interest in the field of microwave absorption(MA).However,the MA effect of common Ti_(3)C_(2)T_(x)-MXene is not prominent and often requires complex processes or combinations of other ma-terials to achieve enhanced *** this context,a kind of gradient woodpile structure using common Ti_(3)C_(2)T_(x)-MXene as MA ma-terial was designed and manufactured through direct ink writing(DIW)3D *** minimum reflection loss(RL_(min))of the Ti_(3)C_(2)T_(x)-MXene-based gradient woodpile structures with a thickness of less than 3 mm can reach-70 dB,showing considerable improve-ment compared with that of a completely filled *** addition,the effective absorption bandwidth(EAB)reaches 7.73 *** study demonstrates that a Ti_(3)C_(2)T_(x)-MXene material with excellent MA performance and tunable frequency band can be successfully fab-ricated with a macroscopic structural design and through DIW 3D printing without complex material hybridization and modification,of-fering broad application prospects by reducing electromagnetic wave radiation and interference.
The coupling between heat and pressure is the kernel of inertia friction welding(IFW)and is still not fully understood.A novel 3D fully coupled finite element model based on a plastic friction pair was developed to si...
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The coupling between heat and pressure is the kernel of inertia friction welding(IFW)and is still not fully understood.A novel 3D fully coupled finite element model based on a plastic friction pair was developed to simulate the IFW process of a Ni-based superalloy and reveal the omnidirectional thermo-mechanical coupling mechanism of the friction *** numerical model successfully simulated the deceleration,deformation processes,and peak torsional moments in IFW and captured the evolution of temperature,contact pressure,and *** simulated results were validated through measured thermal history,optical macrography,and axial *** results indicated that interfacial friction heat was the primary heat source,and plastic deformation energy only accounted for 4%of the *** increase in initial rotational speed and friction pressure elevated the peak temperature,reaching a maximum of 1525.5K at an initial rotational speed of 2000 r/min and friction pressure of 400 *** interface heat generation could form an axial temperature gradient exceeding 320K/*** radial inhomogeneities of heat generation and temperature were manifested in a concentric ring distribution with maximum heat flux and temperature ranging from 2/5 to 2/3 *** radial inhomogeneities were caused by increasing linear velocity along the radius and an opposite distribution of contact pressure,which could reach 1.7 times the set pressure at the *** circumferential inhomogeneity of thermomechanical distribution during rotary friction welding was revealed for the first time,benefiting from the 3D *** deflection and transformation of distribution in contact pressure and Mises stress were indicators of plastic deformation and transition of quasi-steady state *** critical Mises stress was 0.5 times the friction pressure in this *** presented modeling provides a reliable insight into the thermo-mechanical coupling mechanism of IFW and lays a solid found
To address the problem of multi-missile cooperative interception against maneuvering targets at a prespecified impact time and desired Line-of-Sight(LOS)angles in ThreeDimensional(3D)space,this paper proposes a 3D lea...
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To address the problem of multi-missile cooperative interception against maneuvering targets at a prespecified impact time and desired Line-of-Sight(LOS)angles in ThreeDimensional(3D)space,this paper proposes a 3D leader-following cooperative interception guidance ***,in the LOS direction of the leader,an impact time-controlled guidance law is derived based on the fixed-time stability theory,which enables the leader to complete the interception task at a prespecified impact ***,in the LOS direction of the followers,by introducing a time consensus tracking error function,a fixed-time consensus tracking guidance law is investigated to guarantee the consensus tracking convergence of the ***,in the direction normal to the LOS,by combining the designed global integral sliding mode surface and the second-order Sliding Mode Control(SMC)theory,an innovative 3D LOS-angle-constrained interception guidance law is developed,which eliminates the reaching phase in the traditional sliding mode guidance laws and effectively saves energy ***,it effectively suppresses the chattering phenomenon while avoiding the singularity issue,and compensates for unknown interference caused by target maneuvering online,making it convenient for practical engineering ***,theoretical proof analysis and multiple sets of numerical simulation results verify the effectiveness,superiority,and robustness of the investigated guidance law.
Hydroisomerization of n-alkanes plays an important role in fuel and lubricants *** catalysts with ultralow platinum loading have recently been reported successively for ***,the catalysts were prepared successfully wit...
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Hydroisomerization of n-alkanes plays an important role in fuel and lubricants *** catalysts with ultralow platinum loading have recently been reported successively for ***,the catalysts were prepared successfully with different methods to improve the catalytic *** conversion of 0.01%Pt1@CeOx/SAPO-11 prepared by co-calcination method(0.01%Pt1@CS-c)is 71.4%,25%higher than the other prepared by precipitation *** turnover frequency per active surface platinum site(TOFPt)of 0.01%Ptl@CS-c is as high as 13115 h^(-1).Revealed by the X-ray photoelectron spectroscopy(XPS)results,the quality of phase boundary/intersurface between ceria and zeolite is found significantly *** conjunction quality of phase boundary directly affects the spillover rate of intermediate species,which further leads to an apparent activity *** addition,the possible role of ceria in the reaction is discussed,rather than just as a carrier for the active metal atoms.
The Kulun region is located in the eastern Bainaimiao arc belt on the southeastern margin of the Central Asian Orogenic Belt(CAOB),adjacent to the North China Craton(NCC)to the *** region records the closure of the Pa...
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The Kulun region is located in the eastern Bainaimiao arc belt on the southeastern margin of the Central Asian Orogenic Belt(CAOB),adjacent to the North China Craton(NCC)to the *** region records the closure of the PaleoAsian Ocean during the Paleozoic to early Mesozoic and is key to study the tectonic evolution of the northern margin of the *** conducted zircon U-Pb geochronology and Hf isotope analysis of volcanic-sedimentary and intrusive rocks in the Kulun *** volcanic-sedimentary rocks were previously assigned an early Carboniferous age,but include volcanic rocks with ages of 267–266 Ma and sedimentary rocks with youngest detrital zircon age peaks of 265–244 Ma,which were intruded by a granite with an age of 242 *** indicates that these rocks are actually middle Permian to Middle Triassic in age(267–242Ma)and correspond to the Qingfengshan and Liujiagou ***,two volcanic rock samples have highεHf(t)values(+1.6 to+16.1)and relatively young two-stage Hf model ages(1095–327 Ma),indicating their sources associated with the *** age spectra and Hf isotopic characteristics of detrital zircons from the sedimentary rocks suggest that,during the middle Permian to Middle Triassic,the sedimentary provenance in the Kulun region was mainly the ***,by the Early Jurassic,the provenance changed to the NCC(i.e.,the Inner Mongolia Paleo-uplift,IMPU).This result,combined with the development of a series of conglomerates on the northern margin of the NCC in the Late Triassic(i.e.,Xingshikou,Xiaoyingzi,and Xiaohekou formations),indicates the Kulun region experienced an abrupt change in paleogeography during the Late Triassic,with the IMPU undergoing significant uplift and thus becoming the main sediment source in the Kulun *** on the Late Triassic alkaline igneous belt(235–215 Ma)in the IMPU,we speculate that this uplift was caused by detachment of the southward-subducting Paleo-Asian oceanic plate,which occurred in a post-o
This paper proposes a novel impulsive thrust strategy guided by optimal continuous thrust strategy to address two-player orbital pursuit-evasion game under impulsive thrust *** strategy seeks to enhance the interpreta...
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This paper proposes a novel impulsive thrust strategy guided by optimal continuous thrust strategy to address two-player orbital pursuit-evasion game under impulsive thrust *** strategy seeks to enhance the interpretability of impulsive thrust strategy by integrating it within the framework of differential game in traditional continuous ***,this paper introduces an impulse-like constraint,with periodical changes in thrust amplitude,to characterize the impulsive thrust ***,the game with the impulse-like constraint is converted into the two-point boundary value problem,which is solved by the combined shooting and deep learning method proposed in this *** learning and numerical optimization are employed to obtain the guesses for unknown terminal adjoint variables and the game terminal ***,the accurate values are solved by the shooting method to yield the optimal continuous thrust strategy with the impulse-like ***,the shooting method is iteratively employed at each impulse decision moment to derive the impulsive thrust strategy guided by the optimal continuous thrust *** examples demonstrate the convergence of the combined shooting and deep learning method,even if the strongly nonlinear impulse-like constraint is *** effect of the impulsive thrust strategy guided by the optimal continuous thrust strategy is also discussed.
With the continuous control of anthropogenic emissions,China’s air quality has improved significantly in recent *** this background,research on how the short-term exposure risks caused by air pollution in China have ...
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With the continuous control of anthropogenic emissions,China’s air quality has improved significantly in recent *** this background,research on how the short-term exposure risks caused by air pollution in China have changed is *** study utilized hourly concentration data from ground observation stations and the official air quality guidelines of the Ministry of Ecology and Environment of China and the World Health Organization as standards to systematically investigate the spatiotemporal characteristics and short-term exposure risks of air pollution in China from 2015 to *** results indicate that various atmospheric pollutants except for ozone showed a decreasing trend ***,both single pollutant air pollution days(SAPDs)and multiple pollutant air pollution days(MAPDs)showed varying degrees of reduction within 15 and 25 days,*** was dominated mainly by excessive PM_(2.5)and PM_(10)pollutants,while MAPD was dominated mainly by excessive pollutant combinations,including PM_(2.5)+PM_(10),CO+PM_(2.5)+PM_(10),and SO_(2)+PM_(2.5)+PM_(10).As the concentration of atmospheric pollutants decreased,the total excess risk(ER)decreased yearly from 2015 to 2022,but there were significant regional ***,the ER is less than 0.25%in southern China,in the range of 0.25%-0.5%in the North China Plain and some cities in the northeast,and higher than 1%in the *** matter is currently the primary pollutant posing short-term exposure risk in China,especially due to the impact of sandstorm *** study indicates that China’s atmospheric cleaning action is significantly beneficial for reducing health risks.
In the realm of nonlinear integrable systems, the presence of decompositions facilitates the establishment of linear superposition solutions and the derivation of novel coupled systems exhibiting nonlinear integrabili...
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In the realm of nonlinear integrable systems, the presence of decompositions facilitates the establishment of linear superposition solutions and the derivation of novel coupled systems exhibiting nonlinear integrability. By focusing on single-component decompositions within the potential BKP hierarchy, it has been observed that specific linear superpositions of decomposition solutions remain consistent with the underlying equations. Moreover, through the implementation of multi-component decompositions within the potential BKP hierarchy,successful endeavors have been undertaken to formulate linear superposition solutions and novel coupled Kd V-type systems that resist decoupling via alterations in dependent variables.
CO_(2)-to-CO electrolyzer technology converts carbon dioxide into carbon monoxide using electrochemical methods,offering significant environmental and energy benefits by aiding in greenhouse gas mitigation and promoti...
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CO_(2)-to-CO electrolyzer technology converts carbon dioxide into carbon monoxide using electrochemical methods,offering significant environmental and energy benefits by aiding in greenhouse gas mitigation and promoting a carbon circular *** study by Strasser et *** Nature Chemical Engineering presents a high-performance CO_(2)-to-CO electrolyzer utilizing a NiNC catalyst with nearly 100%faradaic efficiency,employing innovative diagnostic tools like the carbon crossover coefficient(CCC)to address transport-related failures and optimize overall ***’s research demonstrates the potential of NiNC catalysts,particularly NiNC-IMI,for efficient CO production in CO_(2)-to-CO electrolyzers,highlighting their high selectivity and ***,challenges such as localized CO_(2)depletion and mass transport limitations underscore the need for further optimization and development of diagnostic tools like *** for optimizing catalyst structure and operational parameters offer avenues for enhancing the performance and reliability of electrochemical CO_(2)reduction catalysts.
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