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Observation of acoustic hybrid topological phases induced by the p-d orbital interactions

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 132-139页

作者： Xiao Xiang Feng Gao Yu-Gui Peng Peng Wu Zong-lin Li Xue-Feng Zhu School of Physics and Innovation Institute Huazhong University of Science and Technology

In spinless systems,growing attention has recently been attracted to synthetic gauge fields,which redefine the fundamental crystal symmetries by utilizing the projective algebraic ***,synthetic gauge fields have been commonly investigated in single orbital systems,and explorations on hybrid orbitals remain elusive in ***,we report the experimental observation of hybrid topological phases induced by hybrid synthetic gauge flux,which is formed by the interaction between p and d orbitals embedded in acoustic *** breaking the translation symmetries of Lxand/or Ly,we unambiguously demonstrate the first-order M?bius edge states and higher-order corner *** work establishes a platform for seeking exotic topological phases induced by hybrid-orbitals interactions and initializing the framework of hybrid-orbitalsrelated topological *** applications can be anticipated in scenarios such as high-quality sensing and robust wave trapping due to the stepwise energy distribution of the hybrid topological phase.

关键词： topological insulator synthetic gauge field projective symmetry corner states

Regulating the key performance parameters for Hg-based IR NLO chalcogenides via bandgap engineering strategy

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Chinese Chemical Letters 2024年第10期35卷 490-494页

作者： A-Yang Wang Sheng-hua Zhou Mao-Yin Ran Xin-Tao Wu hua lin Qi-long Zhu State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of Sciences(CAS)Fuzhou 350002China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China College of Chemistry Fuzhou UniversityFuzhou 350108China University of Chinese Academy of Sciences Bejing 100049China

Recently,non-centrosymmetric(NCS)Hg-based chalcogenides have garnered significant interest due to their strong second-harmonic-generation intensities(deff),making them attractive candidates for infrared nonlinear optical(IR-NLO)***,achieving both wide band gaps(Eg)and large phasematched deffsimultaneously in these materials remains a challenge due to their inherent constraints on each *** this research,we have successfully obtained two quaternary NCS Hg-based chalcogenides,Rb2HgGe_(3)S_(8)and Cs_(2)HgGe_(3)S_(8),by implementing a bandgap engineering strategy that involves alkali metal introduction and Hg/Ge ratio *** compounds consist of 2D[Hg Ge_(3)S_(8)]_(2)–anionic layers made of 1D[HgGeS_(6)]^(6–)chains and dimeric[Ge_(2)S_(6)]_(4–)polyhedra arranged alternately,and the charge-balanced Rb+/Cs+cations located between these ***,Rb_(2)HgGe_(3)S_(8)and Cs_(2)HgGe_(3)S_(8)exhibit overall properties required for promising IR-NLO materials,including sufficient PM deff(0.55–0.70×AgGaS_(2)@20_(5)0 nm),large Eg(3.27–3.41 e V),giant laser-induced damage thresholds(17.4–19.7×AgGaS_(2)@1064 nm),broad optical transmission intervals(0.32–17.5μm),and suitable theoretical birefringence(0.069–0.086@2050 nm).Furthermore,in-depth theoretical analysis reveals that the exceptional IRNLO performance is attributed to the synergy effects of distorted[HgS_(4)]and[GeS_(4)]*** study provides a useful strategy for enhancing the Eg and advancing Hg-based IR-NLO materials,which is expected to extended and implemented in other chalcogenide systems.

关键词： Hg-based chalcogenides IR nonlinear material Structure-activity relationship Wide energy gap Bandgap engineering strategy

Simple yet extraordinary: Super-polyhedra-built 3D chalcogenide framework of Cs_(5)Ga_(9)S_(16) with excellent infrared nonlinear optical performance

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Chinese Chemical Letters 2023年第7期34卷 400-403页

作者： Hong Chen Mao-Yin Ran Sheng-hua Zhou Xin-Tao Wu hua lin Qi-long Zhu State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of Sciences(CAS)Fuzhou 350002China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China University of Chinese Academy of Sciences Bejing 100049China

Non-centrosymmetric chalcogenides are attracting considerable attention as highly promising infrared nonlinear optical (IR-NLO) candidates,but it is challenging to simultaneously achieve sufficient secondharmonic-generation coefficient (d_(eff)>0.5×AgGaS_(2)) and large energy gap (E_g>3.5 e V).In this work,a novel ternary chalcogenide,Cs_(5)Ga_(9)S_(16) with an ultra-wide E_gof 4.05 e V,has been successfully *** sulfide belongs to the monoclinic space group Pn (No.7) with a novel 3D anionic[Ga_(9)S_(16)]^(5–)framework that is formed by super-polyhedral[Ga_(9)S_(23)]units through corner-sharing S *** a unique crystal structure displays desirable characteristics which indicate a promising IR-NLO candidate:favourable phase-matching feature,sufficient d_(eff)(0.7×AgGaS_(2)),ultrahigh laser-induced damage threshold (31.6×AgGaS_(2)) and broad transparent region (0.27-14.96μm).In addition,systematic theoretical studies and structural analysis suggest that the desirable IR-NLO performances can be attributed to the super-polyhedral building *** finding may provide useful insight into the understanding and designing other high-performance IR-NLO candidates with super-polyhedral-built structures.

关键词： Chalcogenide IR nonlinear optic Super-polyhedra-built framework Wide energy gap Structure-activity relationship

Hot Deformation Behavior and Processing Map of Spray Formed M3∶ 2 High Speed Steel

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Journal of Iron and Steel Research International 2016年第5期23卷 501-508页

作者： lin LU long-gang HOU hua CUI Jin-feng huaNG Yong-an ZHANG Ji-shan ZHANG State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing State Key Laboratory of Non-ferrous Metals and Process General Research Institute for Non-ferrous Metals

Hot deformation behavior of a new type of M3∶ 2 high speed steel with niobium addition made by spray forming was investigated based on compression tests in the temperature range of 950-1 150 ℃ and strain rate of 0. 001-10 s^（-1）. A comprehensive constitutive equation was obtained,which could be used to predict the flow stress at different strains. Processing map was developed on the basis of the flow stress data using the principles of dynamic material model. The results showed that the flow curves were in fair agreement with the dynamic recrystallization model. The flow stresses,which were calculated by the comprehensive constitutive equation,agreed well with the test data at low strain rates（ ≤1 s^（-1））. The material constant（ α）,stress exponent（ n） and the hot deformation activation energy（ Q_（HW）） of the new steel were 0. 006 15 MPa^（-1）,4. 81 and 546 kJ·mol^（-1）,respectively. Analysis of the processing map with an observation of microstructures revealed that hot working processes of the steel could be carried out safely in the domain（ T = 1 050-1 150 ℃,ε = 0. 01- 0. 1 s^（-1））with about 33% peak efficiency of power dissipation（ η）. Cracks was expected in two domains at either lower temperatures（〈 1 000 ℃） or low strain rates（ 0. 001 s^（-1）） with different cracking mechanisms. Flow localization occurred when the strain rates exceeded 1 s^（-1） at all testing temperatures.

关键词： high speed steel spray forming hot deformation processing map niobium

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Righting Wrongs

China Today 2025年第1期74卷 45-47页

作者： ZHOU lin 不详

Representatives from nearly 50 countries and regions share their thoughts on how to correct development imbalances and protect people’s rights in all ***,a small village in Zhejiang Province,is known for its beautiful scenery,with white egrets flying in a blue sky and mandarin fish jumping out of the clear water of its lakes and *** houses are equally picturesque,dainty three-storied villas with white walls and black tiles.

关键词： walls beautiful white

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Circle of Friends

China Today 2025年第1期74卷 32-35页

作者： ZHOU lin 不详

CISCE brings together partners on the global industrial chain to collaborate and enhance global *** in South Yorkshire in north-central England,British Steel,originally founded in 1967,is the U.K.’s only manufacturer of *** now produces three million tons of crude steel annually and has the distinction of maintaining stable production even during the COVID-19 pandemic,with its ironmaking,steelmaking and all rolling mills in full operation.

关键词： annually partner CISC

Strengthening Mechanism of a New 700 MPa Hot Rolled High Strength Steel

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Journal of Iron and Steel Research International 2008年第2期15卷 76-80页

作者： YI Hai-long DU lin-xiu WANG Guo-dong LIU Xiang-hua State Key Laboratory of Rolling Technology and Automation Northeastern University Shenyang 110004 Liaoning China

The microstructural evolution in a 700 MPa hot rolled high strength steel was analyzed in terms of strengthening *** results show that the hot rolled sheet steel has yield strength of 710 MPa with good elongation and *** strength of the developed 700 MPa hot rolled high strength steel is derived from the cumulative contribution of fine grain size,dislocation hardening and precipitation *** fine grain strengthening and precipitation hardening are the dominant factors responsible for such high strength,and the amount of precipitation hardening is two or four times higher than that of conventional microalloyed hot rolled sheet steels reported in the *** toughness is due to refinement of ferrite grain size.

关键词： high strength steel strengthening mechanism dislocation hardening precipitation hardening

Effect of coarse TiN inclusions and microstructure on impact toughness fluctuation in Ti micro-alloyed steel

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Journal of Iron and Steel Research International 2018年第10期25卷 1043-1053页

作者： Tao Liu Mu-jun long Deng-fu Chen hua-mei Duan lin-tao Gui Sheng Yu Jun-sheng Cao hua-biao Chen He-lin Fan State Key Laboratory of Coal Mine Disaster Dynamics and Control College of Materials Science and Engineering Chongqing University Chongqing 400044 China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing University Chongqing 400044 China

Toughness is an important property for steels used in engineering applications. However, recent toughness testing has shown the existence of a significant fluctuation in toughness in a single rolled plate of titanium micro-alloyed steel. The underlying causes of this fluctuation were investigated by fractography, analysis of microstructure and measurement of inclusions. Coarse and distributed TiN inclusions were responsible for the toughness variation, as they tended to act as the potential cleavage initiators to form micro-cracks. From a calculation of the local fracture stress, the critical size of coarse TiN inclusions for dominating micro-crack propagation was 4.93 μm, and similarly that of ferrite grains was 36.6μm. Under current casting and thermo-mechanically controlled processing schedules, the toughness fluctuation of rolled steel plates can be primarily attributed to the fraction of coarse TiN inclusions larger than 5μm. A corresponding relationship between impact energy and the proportion of coarse TiN inclusions was established. Finally, a normalizing treatment was applied to refine the ferrite grains of rolled steel plates. Despite the presence of coarse TiN inclusions, this refinement in ferrite grains minimized the toughness fluctuation and improved the uniformity of the impact properties of the steel plates.

关键词： Impact toughness fluctuation Ti micro-alloyed steel Cleavage fracture Coarse TiN inclusion Grain refinement

Influence of Holding Time After Deformation on Bainite Transformation in Niobium Microalloyed Steel

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Journal of Iron and Steel Research International 2007年第5期14卷 62-65页

作者： YI Hai-long DU lin-xiu WANG Guo-dong LIU Xiang-hua State Key Laboratory of Rolling Technology and Automation Northeastern University Shenyang 110004 Liaoning China

Using Gleeble-1500 system, the influence of holding time on bainite transformation in deformed niobium microalloyed steel during continuous cooling was analyzed, and the carbides in upper bainite were also systematically researched. The results show that the occurrence of the static recrystallization decreases the amount of bainite with an increase in the holding time and the emergence of retained austenite （RA） with the longer holding time. Two types of carbides were observed in upper bainite with regard to their precipitation sites. They either existed between the bainite ferrite laths or co-existed with RA. The formation mechanism of two kinds of carbides was analyzed by combining TEM micrographs with the model.

关键词： niobium microalloyed steel bainite carbide static recrystallization retained austenite