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Inherently Chiral and Symmetrical Heteroatom-Doped Zigzag-Type Hydrocarbon Belts

CCS Chemistry 2024年第5期6卷 1198-1210页

作者： xue-yuan wang Xin-Yu Zhang Shuo Tong Qing-Hui Guo Mei-Ling Tan Cheng-Jun Li Mei-Xiang wang Key Laboratory of Bioorganic Phosphorous Chemistry and Chemical Biology(Ministry of Education) Department of ChemistryTsinghua UniversityBeijing 100084

hydrocarbon belts due to their potential applications in carbon *** contrast,heteroatomembedded zigzag hydrocarbon belts as advanced design strategies with fascinating structures and desirable,unique properties have remained largely unexplored,and inherently chiral ones are ***,we report the synthesis of a diversity of symmetric and highly enantiopure inherently chiral O-and N-doped zigzag-type hydrocarbon belts starting from strainless macrocycles based on fjord-stitching *** readily available pertriflated resorcin[6]arene underwent partial hydrolyses and intramolecular S_(N)Ar reactions to form a calix[3](9H-xanthene)derivative and a prochiral half-belt *** transformations of calix[3](9H-xanthene)into C_(3v)-symmetric molecular belts were achieved by closing the rest of the fjords with triple intramolecular S_(N)Ar reactions and Yamamoto homo coupling reactions,as well as palladiumcatalyzed intermolecular acridination reactions with primary *** prochiral half-belt underwent enantioselective desymmetrizative mono-acridination to afford an inherently chiral N,O_(4)-bridged pseudo-belt with an enantiomeric excess(ee)value of>99%under the catalysis of Pd(OAc)_(2)and(R)-*** closure reactions of the pseudo-belt produced diverse heteroatom-inlayed zigzag-type hydrocarbon belts of inherent ***,we showed the unique cavity structures of the belts and demonstrated interesting chiroptic properties of the inherently enantiopure chiral *** research opens the door for the exploration of novel and sophisticated symmetric and inherently chiral molecular nanobelt structures with outstanding physical and chemical properties,as well as potential applications.

关键词： zigzag-type molecular belt heterocycle chiroptical property fjord-stitching strategy resorcinarene

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Signal modeling and impulse response shaping for semiconductor detectors

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Nuclear Science and Techniques 2022年第4期33卷 72-82页

作者： xue-yuan wang Jian-Bin Zhou Ming wang Huai-Ping wang Xu Hong Yi Liu Ping Huang College of Nuclear Technology and Automation Engineering Chengdu University of TechnologyErxian BridgeNo.1 East 3 RoadChenghua DistrictChengdu 610059China Jiangxi Engineering Technology Research Center of Nuclear Geoscience Data Science and System East China University of TechnologyNanchang 330013China China Testing Technology Co. LtdChengdu 610021China

The output-signal models and impulse response shaping(IRS)functions of semiconductor detectors are important for establishing high-precision measurement *** this paper,an output-signal model for semiconductor detector systems is *** to the proposed model,a multistage cascade deconvolution IRS algorithm was developed using the C-R inverse system,R-C inverse system,and differentiator *** silicon drift detector signals acquired from the analog-to-digital converter were *** experimental results indicated that the shaped pulses obtained using the proposed model had no undershoot,and the average peak base width of the output shaped pulses was reduced by 36%compared with that for a simple model proposed in a previous work[1].Offline processing results indicated that compared with the traditional IRS algorithm,the average peak base width of the output shaped pulses obtained using the proposed algorithm was reduced by 11%,and the total elapsed time required for pulse shaping was reduced by 26%.The proposed algorithm avoids recursive *** the sampling frequency of the digital system reaches 100 MHz,the proposed algorithm can be simplified to integer *** proposed IRS algorithm can be applied to high-resolution energy spectrum analysis,highcounting rate energy spectrum correction,and coincidence and anti-coincidence measurements.

关键词： Output-signal model Impulse response shaping C-R inverse system R-C inverse system Integer arithmetic

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Defect-induced magnetism in χ_(3) borophene

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Rare Metals 2022年第10期41卷 3486-3494页

作者： Qiao-Lu Lin Hao Liang Can-Qin Zhou Zheng-Fang Qian Yi-Ling Sun xue-yuan wang Ren-Heng wang Key Laboratory of Optoelectronic Devices and Systems of the Ministry of Education and Guangdong Province College of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen518060China Department of Materials Science and Engineering City University of Hong KongHong Kong999077China

Borophene is an emerging and promising twodimensional material for spintronics ***,the origin and controllability of its magnetism remain poorly understood,thereby hindering the further development of borophene-based *** this study,it is demonstrated that χ_(3) borophene with vacancy defects,which contains zigzag edges and dangling bonds,exhibits spin *** understand the origin and characteristics of its magnetism,a magnetic study of vacancy defects in χ_(3) borophene using first-principles calculations was *** is determined that the unpaired dangling bond electrons in the σ state contribute to its magnetism,and the zigzagged vacancy structure helps to maintain the localization and stability of unpaired *** coupling is completed by the s-p orbital interaction and mediated by p-orbital itinerant *** magnetic coupling energy difference oscillates with the distance of magnetic atoms because of the indirect magnetic exchange by itinerant electrons and electronic shielding,in accordance with the Ruderman-Kittel-Kasuya-Yosida(RKKY)***,the causality between the dangling bonds and magnetism is identified by saturating magnetic B atoms using H,C and N *** study provides a reference for the regulation of borophene in magnetic semiconductors.

关键词： Two-dimensional(2D)materials Borophene Vacancy Magnetic properties First-principles Nanostructure

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Magnetic NiFe_(2)O_(4)@FeNi_(3)core-shell nanospheres derived from FeNi-LDH precursor anchoring on rGO nanosheets for enhanced electromagnetic wave absorption

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Journal of Materials Science & Technology 2024年第4期171卷 101-114页

作者： Kunyao Cao yuan Fang Shuai wang Yue Zhang Jiayue Wen Jun Chen Rui Zhao Weidong xue School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 610054China

Graphene has been extensively utilized in the domain of electromagnetic wave(EMW)absorption ma-terials because of its excellent electrical ***,the inferior impedance matching per-formance and the single loss mechanism vastly restrict the ***,it’s an effective strat-egy to solve these issues by introducing magnetic ***,layer double hydroxide(LDH)is an appropriate template to obtain magnetic component *** that ferromagnetic met-als such as Fe,Co,Ni,and their corresponding metal oxides are usually treated as magnetic compo-nents which are promising candidates for EMW absorption ***,in this work,a FeNi-layered double hydroxide-reduced graphene oxide(FeNi-LDH-rGO)aerogel was synthesized through a series of processes such as electrostatic self-assembly,hydrothermal,freeze-drying,and *** magnetic NiFe_(2)O_(4)@FeNi_(3)core-shell nanospheres were obtained from FeNi-LDH precursor,anchoring on rGO nanosheets after the annealing ***,the effects of different mass ratios of LDH to GO as well as different annealing temperatures of LDH-rGO aerogel on the EMW absorption prop-erty and impedance matching performance were *** a consequence,the fabricated ultralight 600LDH-rGO 2:1 aerogel shows a broad effective absorption bandwidth(EAB)of 7.04 GHz at a thickness of 2.3 mm with a low filling content of only 6 wt%and a low density of 4.4 mg/cm^(3).In conclusion,the synthetic LDH-rGO aerogels offer an effective strategy for preparing EMW absorption materials that own three-dimensional porous network structure and unique magnetic NiFe_(2)O_(4)@FeNi_(3)core-shell struc-ture nanospheres.

关键词： Electrostatic self-assembly Electromagnetic wave absorption LDH-rGO aerogel Layered double hydroxide Reduced graphene oxide NiFe_(2)O_(4)@FeNi_(3)core-shell structure

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Effect of Al content on modification behavior of non-metallic inclusions in high-strength steel treated with rare earth

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Journal of Iron and Steel Research International 2024年第8期31卷 1886-1899页

作者： Zhan-peng Tie xue-yuan Jiang Hai-yan Tang ·Gen Li Yu-hang wang Jia-quan Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Continuous Casting Business Section CISDI Engineering Co.Ltd.Chongqing 401122China Special Steel Institute Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

The influence of Al content(0.0053,0.0171,and 0.0578 wt.%)on the modification behavior of non-metallic inclusions in 20CrMoVTiB steel treated with rare earth elements was studied through high-temperature experiments and thermodynamic *** results showed that the modification products varied with the Al content in steel under 0.01 wt.%of Ce *** formation sequence of typical rare earth inclusions in steel with the increase in Al content was Ce_(2)O_(3)→CeAlO_(3)→CeAl_(11)O_(18),and the final stable products were highly Al content *** the Al content was 0.0053 wt.%,the stable phase in steel was Ce2O3;while the[Al]reached 0.0171 wt.%,the stable phase became CeA1O_(3).As the A1 content reached 0.0578 wt.%,CeAl_(11)O_(18) became the stable *** a result,increasing the Al content could inhibit the precipitation of Ce_(2)O_(3) inclusions in steel while promote the formation of CeAIO3 and CeAl_(11)O_(18) *** addition,both Ca treatment and Ce treatment could effectively refine the size of inclusions in steel by changing their ***,the feeding amount of Ca wire into molten steel should be appropriately reduced under the condition of adding Ce simultaneously,which is expected to be beneficial for an improved Ce treatment effect.

关键词： Rare earth Al content Steel Inclusion Thermodynamics Ca treatment

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Research on feed-pulse collaborative control method in micro-electrical discharge machining

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Advances in Manufacturing 2024年第2期12卷 270-287页

作者： Qiang Gao Ya-Ou Zhang xue-Cheng Xi yuan-Ding wang Xiao-Fei Chen Wan-Sheng Zhao School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai200240People’s Republic of China State Key Laboratory of Mechanical System and Vibration Shanghai200240People’s Republic of China Shanghai Institute of Space Propulsion Shanghai201112People’s Republic of China

Reducing the short-circuit rate and increasing the effective discharge rate are important targets for improving the servo control effect of micro-electrical discharge machining(micro-EDM),as these two indicators are closely related to the machining efficiency and *** this study,a feed-pulse collaborative control(FPCC)method is proposed for micro-EDM based on two dimensions(space and time).In the spatial dimension,a feed control strategy with a discharge holding process is ***,in the time dimension,a forward-looking pulse control strategy is adopted,in which the pulse interval is adjusted based on a sequence analysis of feed commands and discharge *** experiments are carried out to determine the key parameters used in this method,including the discharge holding threshold and pulse interval adjustment value(T_(off_(adj))).The feed smoothness and discharge sufficiency analyses of the experimental results show that compared to the traditional double threshold average voltage method,the FPCC method reduces the number of long-distance retreats by 64%and improves the effective discharge time by 40%.

关键词： Micro-electrical discharge machining(micro-EDM) Electrode feed control Discharge pulse control Machining surface quality

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Simultaneously enhancing erosion and compression resistance:designing AlCoCrFeNi high-entropy alloy strengthened Ag-based contacts

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Rare Metals 2024年第9期43卷 4476-4492页

作者： Xiao-Yang xue Zhe wang Hui-Ling Nie Zhao yuan Jun wang Chang-Hu Xu Kai Wen Cong-Hao Yu School of Materials Science and Engineering Xi’an Polytechnic University School of Physics Xi’an Jiaotong University Key Laboratory of Pulsed Power Technology School of Electrical and Electronic EngineeringHuazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and Technology

Designing microstructures and unveiling dynamic erosion mechanisms remain important challenges for Ag-based contacts. To simultaneously enhance erosion and compression resistance, an Al Co Cr Fe Ni high-entropy alloy(HEA) is introduced into Ag-based materials to fabricate novel Ag-HEA contacts with island-and skeletonrestricted microstructures. The arc erosion experimental results reveal that the skeleton-restricted HEA microstructure is the key factor in reducing the hill and crater morphologies of the contact surface, effectively delaying material transfer between the movable and stationary contacts. The molten bridge evolution and compressive deformation behavior of Ag-HEA contacts with various microstructures are investigated using molecular dynamics(MD) simulations. MD results indicate that the constraint of Ag atom diffusion in the molten pool and the involvement of HEA atoms in the molten bridge are the primary mechanisms for improving erosion resistance. The skeleton-restricted HEA microstructure reduces the total energy and structural stability of the molten bridge system and promotes its fracture and disintegration. Moreover, the synergistic effect of the twin and Lomerz–Cottrell lock structures can hinder dislocation glide, generating dispersed and small-area stacking faults in the Ag matrix and mitigating the concentration of shear strains. Thus, the skeleton-restricted HEA microstructure contributes positively to compression resistance. This study presents a novel approach to designing Ag-based contacts.

关键词： Arc erosion Electrical contact materials High entropy alloys Microstructures Molecular dynamics

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Modification, application and expansion of electrode materials based on cobalt telluride

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Journal of Energy Chemistry 2024年第10期97卷 710-737页

作者： Huilin Fan Yao Dai Xiaoyun xue Runguo Zheng yuan wang Hamidreza Arandiyan Zhiyuan wang Zongping Shao Hongyu Sun Yanguo Liu School of Materials Science and Engineering Northeastern University School of Resources and Materials Northeastern University at Qinhuangdao Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province Northeastern University at Qinhuangdao Department of Chemical Engineering The University of Melbourne Centre for Advanced Materials and Industrial Chemistry (CAMIC) School of Science RMIT University Laboratory of Advanced Catalysis for Sustainability School of Chemistry University of Sydney WA School of Mines: Minerals Energy and Chemical Engineering Curtin University

Metal(Li,Na,K,Al)-ion batteries and lithium-sulfur and lithium-tellurium batteries are gaining recognition for their eco-friendly characteristics,substantial energy density,and sustainable ***,the overall performance of rechargeable batteries heavily depends on their electrode *** metal tellurides have recently gained significant attention due to their high electrical conductivity and *** telluride has received the most extensive research due to its catalytic activity,unique magnetic properties,and diverse composition and crystal ***,its limited conductivity and significant volume variation contribute to electrode structural deterioration and rapid capacity *** review comprehensively summarizes recent advances in rational design and synthesis of modified cobalt telluride-based electrodes,encompassing defect engineering(Te vacancies,cation vacancies,heterointerfaces,and homogeneous interfaces) and composite engineering(derived carbon from precursors,carbon fibers,Mxene,graphene nanosheets,etc.).Particularly,the intricate evolution mechanisms of the conversion reaction process during cycling are ***,these modified strategies applied to other transitional metal tellurides,such as iron telluride,nickel telluride,zinc telluride,copper telluride,molybdenum telluride,etc.,are also thoroughly ***,their application extends to emerging aqueous zinc-ion ***,potential challenges and prospects are discussed to further propel the development of transition metal tellurides electrode materials for next-generation rechargeable batteries.

关键词： Rechargeable batteries Transition metal tellurides Cobalt telluride Defect engineering Composite engineering

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Tailoring sulfur-doped and nitrogen-defective carbon nitride nanosheets for efficient photo-controlled radical polymerizations

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Science China Chemistry 2024年第7期67卷 2325-2334页

作者： xue Li Meng Kai Xu yuan Huang Tao Cai Key Laboratory of Biomedical Polymers of Ministry of Education College of Chemistry and Molecular SciencesWuhan UniversityWuhan 430072China Wuhan University Shenzhen Research Institute Shenzhen 518057China

Despite the challenges that remain,the synergistic adjustment of various microstructures and photochemical parameters of graphitic carbon nitride(g-C_(3)N_(4))in photocatalytic reactions holds promises for improving catalytic efficiency and reducing energy ***,sulfur-doped and nitrogen-defective g-C_(3)N_(4)(n-SC_(3)N_(x))nanosheets were designed and elaborately *** resultant n-SC_(3)N_(x)possessed a precisely defined 2D layer structure with extensive porosity and incremental specific surface *** photoinduced electron transfer-reversible addition-fragmentation chain transfer(PET-RAFT)polymerization of vinyl monomers with low dispersity,excellent temporal control and high chain-end fidelity was achieved under mild blue light irradiation in a nondegassed *** to their ultrathin nanostructures with nitrogen defects and sulfur dopants,n-SC_(3)N_(x)was capable of catalyzing RAFT polymerization in aqueous solutions at significantly accelerated rates,which were nearly 8 times faster compared to bulk g-C_(3)N_(4).The ease of separation and efficient reusability in subsequent polymerizations was enabled by the heterogeneous nature of n-SC_(3)N_(x).The appeal of this approach was illustrated by the fact that utilizing a reusable and metal-free photocatalyst in aqueous environments allowed for the synthesis of polymers with molecular weight up to 300 kg mol^(-1) and a dispersity of 1.32.

关键词： graphitic carbon nitride nitrogen defects sulfur dopants PET-RAFT polymerization recyclability

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Numerical Analysis of Surcharge Effect on Stability and Interaction Mechanism of Slope-Pile-Footing System

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Journal of Earth Science 2024年第3期35卷 955-969页

作者： Chao Xu Lei xue yuan Cui Mengyang Zhai Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Yellow River Laboratory Zhengzhou UniversityZhengzhou 450001China

To investigate the stability and interaction mechanism of the slope-pile-footing system under surcharge effects,the finite difference method(FDM)was adopted to analyze the response laws of the stability of the reinforced slope,evolution of the critical slip surface,stress characteristic of retaining structures,deformation and failure modes of the slope foundation and building footing under surcharge parameters,including the surcharge intensity,the surcharge position,and the surcharge *** results show that surcharge parameters significantly affect the stability and the deformation characteristics of the slope-pile-footing *** speaking,with the increasing surcharge intensity and the decreasing surcharge position and width,the deformation and failure mode of the system will gradually evolve in a direction that is harmful to its *** interaction mechanism of the slope-pile-footing system is further clarified as the load transfer of the building footing,the generation of the additional stress in the slope foundation,and the adjustment of pile bending moment due to the stress ***,the safety of anti-slide piles will determine the stability of the slope foundation and building *** findings are expected to provide guidance for the comprehensive development and utilization of filled slopes after reinforcement.

关键词： slope-pile-footing system slope stability interaction mechanism finite difference method geotechnical engineering safety engineering.

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