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Secondary Precipitation Behavior of Nitride in the Electro-slag Remelted Structure of Alloy 690

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Acta Metallurgica Sinica(English Letters) 2017年第8期30卷 771-780页

作者： Min Wang Bo Chen xian-chao hao Ying-Che Ma Kui Liu Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

The precipitation and evolution of secondary nitrides （S-nitrides） in the Alloy 690 electro-slag remelted （ESR） structure were investigated. Experimental results indicate that S-nitrides precipitated in the interdendritic region of the ESR structure at temperatures higher than 1100 ℃. S-nitrides could spread throughout the entire interdendritic area after sufficient exposure, and they were more numerous and much finer than primary nitrides. Furthermore, after studying the evolution of S-nitride particles at 1100, 1200 and 1300℃, it was determined that the precipitation of S-nitrides was controlled by the diffusion of nitrogen. In addition, by investigating the elemental segregation of ESR structure and calculating critical Ti concentrations, S-nitride precipitation was found to be thermodynamically inevitable in the Alloy 690 ESR structure.

关键词： Alloy 690 ESR Nitride Precipitation

Effect of Co on Microstructure and Stress Rupture Properties of K4750 Alloy

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Acta Metallurgica Sinica(English Letters) 2019年第12期32卷 1501-1510页

作者： Xiao-Xiao Li Mei-Qiong Ou Min Wang xian-chao hao Ying-Che Ma Kui Liu Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China

The effects of substituting Co for Fe on the microstructure and stress rupture properties of K4750 alloy were *** microstructure of the alloy without Co(K4750 alloy)and the alloy containing Co(K4750-Co alloy)were *** of Co for Fe inhibited the decomposition of MC carbide and the precipitation ofηphase during long-term aging *** K4750-Co alloy,the morphology of MC carbide at the grain boundary(GB)remained dispersed blocky shape and noηphase was observed after aging at 750℃ for 3000 ***,in K4750 alloy,almost all the MC carbides at GBs broke down into granular M23C6 carbide and needle-likeη*** addition of cobalt could delay the decomposition of MC carbides,which accordingly restricted the elemental supply for the formation ofη*** stress rupture tests were conducted on two alloys at 750℃/430 *** Co is substituted for Fe in K4750 alloy,the stress rupture life increased from 164.10 to 264.67 h after standard heat *** was mainly attributed to increased concentration of Al,Ti and Nb inγ’phase in K4750-Co alloy,which further enhanced the strengthening effect ofγ’*** aging at 750℃ for 3000 h,substitution of Co for Fe can also cause the stress rupture life at 750℃/430 MPa to increase from 48.72 to 208.18 *** reason was mainly because MC carbide degradation andηphase precipitation in K4750 alloy,which promoted the initiation and propagation of micro-crack during stress rupture testing.

关键词： Nickel-based superalloy Co addition MC degradation Stress rupture property

Electrostatically connected nanoarchitected electrocatalytic films for boosted water splitting

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Nano Research 2024年第3期17卷 1114-1122页

作者： chao-Peng Wang hao Sun Gang Bian Jia-Xi Wang Xixi Pang Guoqi Wang Jian Zhu xian-He Bu School of Materials Science and Engineering National Institute for Advanced MaterialsNankai UniversityTianjin 300350China Tianjin Key Laboratory of Metal and Molecule-Based Material Chemistry Nankai UniversityTianjin 300350China Tianjin Key Laboratory for Rare Earth Materials and Applications Nankai UniversityTianjin 300350China

Active sites of two-dimensional(2D)electrocatalysts are often partially blocked owing to their inevitable stacking and hydrophobic polymeric binders in macroscale electrodes,therefore impeding their applications in efficient ***,using layered double hydroxide(LDH)nanosheets as a model 2D electrocatalyst,we demonstrate that their performance toward water splitting can be boosted when they are electrostatically assembled into an organized structure pillared by hydrophilic polyelectrolytes or nanoparticles in a layer-by-layer(LbL)*** particular,their mass activity on a planar electrode can be as large as 2.267 mA·μg^(-1) toward oxygen evolution reaction(OER),when NiFe-LDH nanosheets are electrostatically connected by poly(sodium 4-styrenesulfonate)(PSS),while drop-casted NiFe-LDH nanosheets only have a mass activity of 0.116 mA·μg^(-1).In addition,these homogeneous NiFe-LDH nanofilms can be easily deposited on three-dimensional(3D)surfaces with high areas,such as carbon cloths,to serve as practical electrodes with overpotentials of 328 mV at a current density of 100 mA·cm^(-2),and stability for 40 ***,Pt nanoparticles can be LbL assembled with NiFe-LDH as bifunctional electrodes for synergistically boosted oxygen and hydrogen evolution reactions(HER),leading to successful overall water splitting powered by a 1.5 V *** study heralds the spatial control of 2D nanomaterials in nanoscale precision as an efficient strategy for the design of advanced electrocatalysts.

关键词： layer-by-layer(LbL)assembly layered double hydroxides(LDH) two-dimensional(2D)electrocatalysts oxygen evolution reaction(OER) water splitting

Recent advances in vacancy engineering for reliable lithiumsulfur batteries

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Rare Metals 2024年第2期43卷 455-477页

作者： Wen-Dong Liu Xiao Tang Jun-An Feng chao-Yue Zhang hao Liu Chuan Shi Xiao-xian Zhao Jian-Jun Song College of Physics School of Chemistry and Chemical EngineeringQingdao UniversityQingdao266071China Faculty of Science Centre for Clean Energy TechnologySchool of Mathematical and Physical SciencesUniversity of Technology SydneySydneyNSW2007Australia Department of Chemistry College of ScienceHebei Agricultural UniversityBaoding071001China

The high-energy-density and low-cost features endow lithium-sulfur batteries with broad application ***,many drawbacks,especially the detrimental shuttle effect,have hindered the further development of *** response,a lot of new structures have been applied to suppress the shuttle effect and promote the development of ***,vacancy engineering has gained the attention of researchers due to its unique electronic *** review aims to analyze the application of vacancy engineering in ***,the electrochemistry of LSBs has been systematically discussed and the existing challenges as well as improvement tactics of LSBs have also been ***,the preparation methods and characterization technologies of various vacancies are summarized,including oxygen vacancies,sulfur vacancies,selenium vacancies,other anion vacancies,cation vacancies,*** latest applications of vacancy engineering in LSBs are also summarized in this ***,some prospects and insights for further investigation and practical application of vacancy engineering in LSBs are put forward.

关键词： Lithium-sulfur batteries(LSBs) Defects Vacancy engineering Electronic structure Shuttle effect

Spatial covariant gravity with two degrees of freedom in the presence of an auxiliary scalar field:Perturbation analysis

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Chinese Physics C 2024年第8期48卷 198-212页

作者： Zhi-chao Wang xian Gao School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China

We investigate a class of gravity theories respecting only spatial covariance,termed spatially covariant gravity,in the presence of an auxiliary scalar *** examine the conditions on the Lagrangian required to eliminate scalar degrees of freedom,allowing only two tensorial degrees of freedom to *** of strict constraint analysis,in this paper,we employ the perturbation method and focus on the necessary conditions to evade the scalar mode at the linear order in perturbations around a cosmological *** with a general action and solving the auxiliary perturbation variables in terms of a would-be dynamical scalar mode,we derive the condition to remove its kinetic term,thus ensuring that no scalar mode *** an application of the general condition,we study a polynomial-type Lagrangian as a concrete example,in which all monomials are spatially covariant scalars containing two *** find that the auxiliary scalar field is essential,and new terms in the Lagrangian are *** analysis provides insights into constructing gravity theories with two degrees of freedom in the extended framework of spatially covariant gravity.

关键词： modified gravity cosmological perturbation theory gravitational theory

Full-domain collaborative deployment method of multiple interference sources and evaluation of its deployment effect

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Defence Technology（防务技术） 2024年第2期32卷 572-595页

作者： Yue Wang Fuping Sun xian Wang Jinming hao Kai Xiao School of Geospatial Information The PLA Information Engineering UniversityZhengzhou 450001HenanChina

This paper realizes the full-domain collaborative deployment of multiple interference sources of the global satellite navigation system(GNSS)and evaluates the deployment effect to enhance the ability to disturb the attacker and the capability to defend the GNSS during navigation *** evaluation indicators for the jamming effect of GNSS suppressive and deceptive jamming sources are first created,their evaluation models are built,and their detection procedures are sorted out,as the basis for determining the deployment *** principles for collaboratively deploying multi-jamming sources are developed to obtain the deployment structures(including the required number,structures in demand,and corresponding positions)of three single interference sources required by collaboratively ***,simulation and hardware-in-loop testing results are presented to determine a rational configuration of the collaborative deployment of multi-jamming sources in the set situation and further realize the full-domain deployment of an interference network from ground,air to *** evaluation indices for the deployment effect are finally developed to evaluate the deployment effect of the proposed configuration and further verify its reliability and rationality.

关键词： Jamming effect Multiple interference sources Collaborative deployment Effect evaluation Defense capability

Delving into high-quality SVBRDF acquisition: A new setup and method

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Computational Visual Media 2024年第3期10卷 523-541页

作者： Chuhua xian Jiaxin Li hao Wu Zisen Lin Guiqing Li School of Computer Science and Engineering South China University of TechnologyGuangzhou 510006China Guangdong Shidi Intelligence Technology Ltd.Guangzhou 510000China

In this study, we present a new andinnovative framework for acquiring high-qualitySVBRDF maps. Our approach addresses the limitations of the current methods and proposes a newsolution. The core of our method is a simple hardwaresetup consisting of a consumer-level camera, LEDlights, and a carefully designed network that canaccurately obtain the high-quality SVBRDF propertiesof a nearly planar object. By capturing a ﬂexiblenumber of images of an object, our network usesdifferent subnetworks to train different property mapsand employs appropriate loss functions for each ofthem. To further enhance the quality of the maps, weimproved the network structure by adding a novel skipconnection that connects the encoder and decoder withglobal features. Through extensive experimentation usingboth synthetic and real-world materials, our resultsdemonstrate that our method outperforms previousmethods and produces superior results. Furthermore,our proposed setup can also be used to acquire physicallybased rendering maps of special materials.

关键词： acquisition setup SVBRDF acquisition material capture global skip connection

Preparing cyclic polymers at high concentrations via self-folding cyclization technique by adjusting the contents of hydrophilic units in linear precursors

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Chinese Chemical Letters 2024年第2期35卷 283-288页

作者： hao Zha Zuowei Wang chao Liu Chunyan Hong Department of Polymer Science and Engineering University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China

Cyclic polymers are a class of polymers that feature endless topology,and the synthesis of cyclic polymers has attracted the attention of many ***,cyclic polymers were efficiently constructed by self-folding cyclization technique at high *** poly((oligo(ethylene glycol)acrylate)-co-(dodecyl acrylate))(P(OEGA-co-DDA))precursors with different ratios of hydrophilic and hydrophobic moieties were synthesized by reversible addition-fragmentation chain transfer(RAFT)polymerization using a bifunctional chain transfer agent with two anthryl end *** amphiphilic linear precursors underwent the self-folding process to generate polymeric nanoparticles in *** irradiating the aqueous solution of the nanoparticles with 365 nm UV light,cyclic polymers were synthesized successfully via coupling of anthryl *** effects of the ratios of hydrophilic and hydrophobic moieties in linear P(OEGA-co-DDA)copolymers and polymer concentration on the purity of the obtained cyclic polymers were explored in detail via ^(1)H nuclear magnetic resonance(^(1)H NMR),dynamic light scattering(DLS),UV‒visible(vis)analysis,three-detection size exclusion chromatography(TD-SEC)and transmission electron microscopy(TEM).It was found that by adjusting the content of the hydrophilic segments in linear precursors,single chain polymeric nanoparticles(SCPNs)can be generated at high polymer ***,cyclic polymers with high purity can be constructed *** method overcomes the limitation of traditional ring-closure method,which is typically conducted in highly dilute conditions,providing an efficient method for the scalable preparation of cyclic polymers.

关键词： Cyclic polymers Self-folding cyclization technique Single chain polymeric nanoparticles RAFT polymerization Direct visualization

Al-containing Ge-rich IWV:rapid synthesis via interzeolite transformation and application in Baeyer-Villiger oxidation

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Science China Chemistry 2024年第7期67卷 2282-2291页

作者： Meichen Jiao Chunmin Jia hao Xu Peng Wu xian-Ming Zhang School of Chemistry&Material Science Shanxi Normal UniversityTaiyuan 030006China Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200062China School of Chemistry Taiyuan University of TechnologyTaiyuan 030024China

Ge-containing Lewis acidic zeolites are typically synthesized using a conventional hydrothermal strategy from amorphous silica sources,through a long time-and energy-consuming approach limiting their wide *** study reports a rapid synthesis strategy for a series of IWV aluminogermanosilicate zeolites(T-x-Al)with a wide range of Si/Ge molar ratios(5–15)by interzeolite transformation of dealuminated FAU(DA-FAU).Notably,Ge-rich IWV could be obtained with crystallization time as short as one day by the equimolecular Si/Ge ratio *** effect of synthetic parameters was investigated and the obtained T-x-Al samples were characterized by XRD,SEM,EDS,ICP,^(29)Si and^(27)Al MAS NMR,FTIR,and N_(2)physisorption *** with a previously reported IWV germanosilicate(H-3),T-x-Al displayed a better catalytic activity in Baeyer-Villiger(BV)oxidation,attributed to the presence of the active framework Ge sites with the assistance of the extraframework Al *** cyclic catalysis tests revealed that the presence of framework Al species contributed to the stability of the ***,T-x-Al,with 14-membered ring(MR)supercages,outperformed the typical 12-MR Sn-beta catalyst in the BV oxidation of large ketone-like 2-admantanone,indicating a promising potential application in the macromolecular catalytic process.

关键词： Ge-rich IWV interzeolite transformation Al assistance Baeyer-Villiger oxidation