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Enhanced electromagnetic wave absorption via optical fiber-like PMMA@Ti_(3)C_(2)T_(x)@SiO_(2) composites with improved impedance matching

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Nano Research 2024年第3期17卷 1676-1686页

作者： Huanhuan Niu Xuewen Jiang Wei Li Zhiyu Min Budi Riza Putra Wulan Tri Wahyuni Hailong Wang Rui Zhang Bingbing Fan School of material science and engineering Zhengzhou UniversityZhengzhou 450001China School of materials science and engineering Tongji UniversityShanghai 201804China Department of materials and Earth sciences Technical University of DarmstadtDarmstadt 64287Germany School of material science and engineering Luoyang Institute of Science and TechnologyLuoyang 471023China Research Center for Metallurgy National Research and Innovation Agency(BRIN)PUSPIPTEK Gd.470South TangerangBanten 15315Indonesia Analytical Chemistry Division Department of ChemistryFaculty of Mathematics and Natural SciencesIPB UniversityWest Java 16680Indonesia

Ti_(3)C_(2)T_(x) nanosheets have attracted significant attention for their potential in electromagnetic wave absorption(EWA).However,their inherent self-stacking and exorbitant electrical conductivity inevitably lead to serious impedance mismatch,restricting their EWA ***,the optimization of impedance matching becomes *** this work,we developed polymethyl methacrylate(PMMA)@Ti_(3)C_(2)T_(x)@SiO_(2) composites with a sandwich-like core–shell structure by coating SiO_(2) on PMMA@Ti_(3)C_(2)T_(x).The results demonstrate that the superiority of the SiO_(2) layer in combination with PMMA@Ti_(3)C_(2)T_(x),outperforming other relative graded distribution structures and meeting the requirements of EWA *** resulting PMMA@Ti_(3)C_(2)T_(x)@SiO_(2) composites achieved a minimum reflection loss of-58.08 dB with a thickness of 1.9 mm,and an effective absorption bandwidth of 2.88 *** analysis revealed that the structural design of SiO_(2) layer not only optimized impedance matching,but also synergistically enhanced multiple loss mechanisms such as interfacial polarization and dipolar ***,this work provides valuable insights for the future preparation of high-performance electromagnetic wave absorbing Ti_(3)C_(2)T_(x)-based composites.

关键词： polymethyl methacrylate(PMMA)@Ti_(3)C_(2)T_(x)@SiO_(2)composites impedance match SiO_(2)layer optical fiber-like structure interfacial polarization and dipolar polarization

Shedding light on the reversible deactivation of carbon-supported single-atom catalysts in hydrogenation reaction

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Nano Research 2024年第6期17卷 4807-4814页

作者： Runze Chen Xiaoying Wang Jianfei Dang Songjie Yun Liqiang Wang Fangong Kong You-Nian Liu State Key Laboratory of Biobased material and Green Papermaking Qilu University of TechnologyJinan 250353China School of material science and engineering Zhengzhou UniversityZhengzhou 450001China School of Chemical engineering Zhengzhou UniversityZhengzhou 450001China Hunan Provincial Key Laboratory of Micro&Nano materials Interface science College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China

Carbon-supported single-atom catalysts were found to suffer reversible deactivation in catalytic hydrogenation,but the mechanism is still ***,nitro compounds hydrogenation catalyzed by N-doped carbon-supported Co single atom(Co1/NC)was taken as a model to uncover the mechanism of the reversible deactivation ***1/NC exhibited moderate adsorption towards the substrate molecules(i.e.,nitro compounds or related intermediates),which could be strengthened by the confinement effect from the porous ***,substrate molecules tend to accumulate within the pore channel,especially micropores that host Co1,making it difficult for the reactants to access the active sites and finally leading to their *** situation could be even worse when the substrate molecules possess a large ***,the catalytic activity of Co1/NC could be restored via a simple thermal treatment,which could remove the adsorbates within the pore channel,hence releasing active sites that were originally inaccessible to reactants.

关键词： single-atom catalysts porous carbon support reversible deactivation mechanistic study hydrogenation reaction

Microstructure and mechanical properties of Ti/Al/Ti clad plates prepared via powder-in-tube method

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Journal of Iron and Steel Research(International) 2024年第3期31卷 670-687页

作者： Xian-lei Hu Qin-cheng Xie Yi Yuan Ying Zhi State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina Suzhou Dongbao Haixing Metal material Technology Co. Ltd.Suzhou 215600JiangsuChina School of material science and engineering Northeastern UniversityShenyang 110819LiaoningChina

The Ti/Al/Ti clad plates exhibit a broad spectrum of potential ***,the conventional techniques of hot-pressing composite and explosive composite are intricate and environmentally hazardous.A novel method was introduced for preparing clad plates,namely,the powder-in-tube *** method involves a combination of cold rolling,annealing at a temperature of 550℃,and double *** morphology of the intermetallic compound layer was analyzed through the utilization of interface stripping test,tensile test,and microscopic *** interface morphology,interface bonding properties,tensile fracture structures,and properties of plates under the first and second rolling were compared,along with the effects of intermetallic compounds on the interface *** results indicate that the powder-in-tube method,when annealed at 550℃,can produce a composite plate featuring a complete and uniform Ti/Al *** obtained plate exhibits a peeling strength of 21.5 N/mm,tensile strength of 424 MPa,and elongation of 11.5%.Furthermore,a systematic analysis was conducted to determine the causes of performance degra-dation observed during annealing at temperatures of 600 and 650℃.

关键词： Powder-in-tube method-Ti/Al/Ti clad plate Annealing Cold rolling-Mechanical property

Cation-Dipole Interaction-Induced Coacervate Underwater Adhesives in Natural Seawater

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Chinese Journal of Polymer science 2024年第7期42卷 984-991,I0009页

作者： Xu-Fei Liu Chong-Rui Zhang Hua-Wen Peng Qiang Zhao Key Laboratory of material Chemistry for Energy Conversion and Storage Ministry of EducationSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan430074China

Significant progress has been made in wet adhesives for low salinity water,but exploration of general ionic adhesives for natural seawater is less developed because the high salinity could weaken interfacial bonding and shields electrostatic interactions,resulting in adhesion ***,the design of adhesives for natural seawater represents challenges less ***,a cationic polyelectrolyte(PECHIA)containing imidazolacetonitrile unit was explored to prepare adhesives enabled by natural *** combining the ion shielding effect with the“cation-dipole”interactions between PECHIA chains,aqueous solution of the PECHIA underwent coacervation and self-crosslinking in natural seawater,allowing for underwater adhesion to various substrates in *** instantaneous lap-shear and tensile adhesion strengths are 47 and 119 kPa,respectively,while the cured adhesive shows~739 k Pa tensile adhesion in natural *** design of PECHIA enables wet adhesives viable for applications in the diversified scenarios of natural seawater.

关键词： Coacervate Underwater adhesives Seawater Cation-dipole interaction

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The Application of Permanent Magnet Synchronous Motor with Small Electrical Time Constant in Fiber Positioner

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Research in Astronomy and Astrophysics 2024年第1期24卷 212-222页

作者： Shaoxiong Guo Yan Yang Yanbin Yin Yihu Tang Yang Tian Chao Zhai Department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei 230026China School of Biomedical engineering Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230026China Experiment Center of engineering and material science University of Science and Technology of ChinaHefei 230026China

With the development of cutting-edge multi-object spectrographs,fiber positioners located in the focal plane are being scaled down in size,and miniature hollow-cup Permanent Magnet motors are now being considered as a suitable replacement for Faulhaber Precistep stepper ***,the small electrical time constant of such coreless motors poses a challenge,as the problem of severe commutation torque ripple in a fiber positioner running a position loop has been *** overcome this challenge,it is advised to increase the Pulse Width Modulation(PWM)frequency as much as possible to mitigate the effects of the current *** must be done while ensuring adequate resolution of the PWM *** employing a voltage open-loop field-oriented control based on a modulation frequency of 1 MHz,the drive current only costs 25 m A under a 3.3 V power *** sine degree of phase current is immaculate,and the repeat positioning accuracy can reach 2μ***,it is possible to further shrink the bill of devices and the layout area of the Printed Circuit Board,especially in sizesensitive *** device has been developed under the new generation of The Large Sky Area MultiObject Fiber Spectroscopic Telescope.

关键词： instrumentation:adaptive optics instrumentation:spectrographs proper motions reference systems

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Effect of heat treatment on microstructure and mechanical properties of selective laser-melted PH13-8Mo stainless steel

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Journal of Iron and Steel Research(International) 2024年第4期31卷 945-955页

作者： Yuan Zhang Xiang Liu Chang-jun Wang Chang Liu School of material science and engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Central Iron&Steel Research Institute Co. Ltd.Beijing 100081China

PH13-8Mo stainless steel powder with high sphericity and well fluidity was prepared by the plasma rotating electrode *** formed parts with ultra-high purity were manufactured by selective laser *** tensile and impact mechanical properties of the printed parts under three heat treatment regimes were compared to those without heat *** microstructure,grain orientation and phase composition were characterized by electron-backscatter diffraction,X-ray diffraction and transmission electron *** characterization results reveal that the addition of heat treatment makes the grains enlarge,and after different heat treatments,the average grain size from 1.51μm in the printed state increases to 2.78,3.09 and 2.06μm,*** formed parts are mainly composed of martensite and retained ***,the NiAl and M23C precipitates form,which are the major strengthening phases of PH13-8Mo stainless *** optimal heat treatment process is 925℃×1 h water cooling(WC)+0℃×2 h air cooling(AC)+540℃×4 h *** this heat treatment process,PH13-8Mo formed parts have the optimal comprehensive mechanical properties:the tensile strength,yield strength and impact energy KU2 are 1492 MPa,1432 MPa and 63 J,*** strengthening and toughening via heat treatment are mainly attributed to dislocation strengthening,the formation of NiAl and M23Co precipitates and the change of volume fraction of the retained austenite.

关键词： High-strength stainless steel-Selective laser melting-Heat treatment Microstructure Mechanical property

Spray pyrolysis-derived W-doped MoSe2/rGO paper-like microspheres:optimization of microstructure and mesostructure for enhanced lithium storage

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Rare Metals 2024年第7期43卷 3019-3031页

作者： Wei Wang Jun-Yu Chen Jie Ouyang Hong Yin Ao-Jie Li Liang Chen Jun-Lin Huang Yu-Can Zhu Gang-Yong Li Zhao-Hui Hou Key Laboratory of Hunan Province for Advanced Carbon-based Functional materials Hunan Institute of Science and Technology School of Chemistry and Chemical engineering Hunan Institute of Science and Technology Hunan Province Key Laboratory of materials Surface & Interface science and Technology Material Science and Engineering SchoolCentral South University of Forestry and Technology International Iberian Nanotechnology Laboratory (INL)

Two-dimensional MoSe2is a promising candidate for lithium-ion battery ***,its conductivity and lithium storage volumetric effect still need to be *** this work,W-doped MoSe2/rGO paper-like microspheres are successfully prepared through ultrasonic spray pyrolysis,achieving optimization at both the microstructure and mesostructure to enhance the lithium storage performance of the ***,by utilizing the similar two-dimensional structure between MoSe2and rGO,self-assembly is achieved through spray pyrolysis,resulting in a well-defined van der Waals heterostructure at the interface on the microscale,enhancing the electron and ion transfer capability of the ***,the mesoscale paper-like microsphere morphology provides additional volume expansion buffering ***,W-doping not only increases the interlayer spacing of MoSe2（0.73 nm）,thereby reducing the diffusion resistance of Li+,but also allow for the modulation of the energy band structure of the *** functional theory（DFT） calculations confirm that W-doped MoSe2/rGO exhibits the narrowest bandgap（0.892 eV）.Therefore,the composite demonstrates excellent lithium storage performance,maintaining a specific capacity of 732.9 mAh·g-1after 300 cycles at a current density of 1 A·g-1.

关键词： Molybdenum selenide Heterostructure Microspheres Li-ion batteries Kinetics

Visible-light-driven photocatalysis degradation of antibiotic pollutants by La-doped CeO2 nanorods:synergy of La doping and oxygen vacancy

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Rare Metals 2024年第7期43卷 3134-3145页

作者： Shi-Hai Cao Jing-Ru Qu Yu-Qi Zhao Yun-Tong Sun Wen-Tong Gao Bing Han Yao Lu College of Environmental engineering Nanjing Institute of Technology School of materials science and engineering Nanjing Institute of Technology School of Chemistry Chemical Engineering and BiotechnologyNanyang Technological University Institute of Environmental Health and Ecological Security School of Environment and Safety EngineeringJiangsu University Jiangsu Collaborative Innovation Center of Technology and material of Water Treatment Suzhou University of Science and Technology

Elemental doping is an effective strategy to enhance photocatalytic activity and extend the light absorption range of single-component *** this work,a series of La-doped CeO2nanorods（La-CeO2-x） with La content of 1 wt%-15 wt% are synthesized by a simple hydrothermal method and further used as photocatalyst for sulfamerazine（SMR） *** prepared La-CeO2-x nanorods exhibit a great improvement in electron-hole pair migration and visible-light response due to the synergistic effect of abundant oxygen vacancies and heterogeneous elements（La）.Consequently,La-CeO2-x exhibited excellent visible-light photocatalytic performances and chemical stability for SMR degradation,the La-CeO2-5 sample achieved the highest SMR degradation rate of 81%,which was 3.4 times higher than that of the original ***,three possible degradation pathways of SMR in La-CeO2photocatalytic reactions were proposed by liquid chromatography-mass spectrometry ***,density functional theory calculations were carried out to provide an in-depth understanding of the structure-performance *** its excellent properties and better photocatalytic performance,this study demonstrates that La doping in CeO2is an effective way to increase oxygen vacancy and improve the photochemical properties of photocatalysts.

关键词： CeO 2 nanorod La-doped Photocatalysis Oxygen vacancy Sulfamerazine

Unraveling magnetic properties and martensitic transformation in Mn-rich Ni-Mn-Sn alloys:first-principles calculations and experiments

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Rare Metals 2024年第4期43卷 1769-1785页

作者： Yu Zhang Jing Bai Ke-Liang Guo Jia-Xin Xu Jiang-Long Gu Nicola Morley Qui-Zhi Gao Yu-Dong Zhang Claude Esling Xiang Zhao Liang Zuo Key Laboratory for Anisotropy and Texture of materials(Ministry of Education) School of Material Science and EngineeringNortheastern UniversityShenyang110819China Key Laboratory of Dielectric and Electrolyte Functional material Hebei Province School of Resources and MaterialsNortheastern University at QinhuangdaoQinhuangdao066004China Department of material science and engineering University of SheffieldSheffieldS13JDUK State Key Laboratory of Metastable materials science and Technology Yanshan UniversityQinhuangdao066004China Laboratoire d’Étude des Microstructures Et de Mécanique des Matériaux University of Lorraine57045MetzFrance

We have investigated the phase stability,magnetic properties,and martensitic transformation thermodynamics/kinetics of the Ni_(24-x)Mn_(18+x+y)Sn_(6-y)(x,y=0,1,2)system by combining the first-principles calculations and *** calculation results show that the optimized lattice parameters are consistent with the experimental ***,we obtain the relation equation for the austenite formation energy(E_(form-A))and Mn content(X_(Mn)):E_(form-A)=507.358X_(Mn)-274.126,as well as for the six-layer modulated(6M)martensite formation energy(E_(form-6M))and Ni content(X_(Ni)):E_(form-6M)=-728.484X_(Ni)+*** ternary phase diagram of the total magnetic moment was *** excess Mn will reduce the total magnetic moment of 6M(Mag6M)and non-modulated(NM)(MagNM)martensites,with the following equations relating the total magnetic moment and Mn content:Mag_(6M)=-15.905X_(Mn)+7.902and Mag_(NM)=-14.781X_(Mn)+7.411,while the effect on austenite is *** variation of total magnetic moment is mainly dominated by the Mn atomic magnetic *** 3d electrons of Mn_(Sn)(Mn at Sn sublattice)play an important role in magnetic properties from the perspective of the electronic density of *** on the thermodynamics of martensitic transformation,the alloys will likely undergo austenite?6M?NM transformation *** the thermodynamic and kinetic results,the martensitic transformation temperature decreases with x increasing and increases with y *** results are expected to provide reference for predicting the phase stability and magnetic properties of NiMn-Sn alloys.

关键词： Ni-Mn-Sn First-principles calculations Martensitic transformation Magnetic property Kinetics

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