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Investigation of high rate mechanical flow followed by ignition for high-energy propellant under dynamic extrusion loading

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Defence Technology（防务技术） 2024年第2期32卷 336-347页

作者： Liying Dong Yanqing Wu Kun Yang xiao hou State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

Investigating the ignition response of nitrate ester plasticized polyether(NEPE) propellant under dynamic extrusion loading is of great significant at least for two cases. Firstly, it helps to understand the mechanism and conditions of unwanted ignition inside charged propellant under accident ***, evaluates the risk of a shell crevice in a solid rocket motor(SRM) under a falling or overturning scene. In the present study, an innovative visual crevice extrusion experiment is designed using a dropweight apparatus. The dynamic responses of NEPE propellant during extrusion loading, including compaction and compression, rapid shear flow into the crevice, stress concentration, and ignition reaction, have been firstly observed using a high-performance high-speed camera. The ignition reaction is observed in the triangular region of the NEPE propellant sample above the crevice when the drop weight velocity was 1.90 m/s. Based on the user material subroutine interface UMAT provided by finite element software LS-DYNA, a viscoelastic-plastic model and dual ignition criterion related to plastic shear dissipation are developed and applied to the local ignition response analysis under crevice extrusion conditions. The stress concentration occurs in the crevice location of the propellant sample, the shear stress is relatively large, the effective plastic work is relatively large, and the ignition reaction is easy to occur. When the sample thickness decreases from 5 mm to 2.5 mm, the shear stress increases from 22.3 MPa to 28.6 MPa, the critical value of effective plastic work required for ignition is shortened from 1280 μs to 730 μs, and the triangular area is easily triggering an ignition reaction. The propellant sample with a small thickness is more likely to stress concentration, resulting in large shear stress and effective work, triggering an ignition reaction.

关键词： NEPE propellant Crevice extrusion Shear flow Sample thickness Ignition reaction

Signifying quantum uncertainty relations by optimal observable sets and the tightest uncertainty constants

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Science China(Physics,Mechanics & Astronomy) 2024年第9期Mechanics & Astronomy) .卷 47-54页

作者： xiao-Bin Liang Bo Li shao-Ming Fei School of Mathematics and Computer Science Shangrao Normal University Quantum Information Research Center Shangrao Normal University School of Mathematical Sciences Capital Normal University

Quantum uncertainty relations constrain the precision of measurements across multiple non-commuting quantum mechanical observables. Here, we introduce the concept of optimal observable sets and define the tightest uncertainty constants to accurately describe these measurement uncertainties. For any quantum state, we establish optimal sets of three observables for both product and summation forms of uncertainty relations, and analytically derive the corresponding tightest uncertainty constants. We demonstrate that the optimality of these sets remains consistent regardless of the uncertainty relation form. Furthermore, the existence of the tightest constants excludes the validity of standard real quantum mechanics, underscoring the essential role of complex numbers in this field. Additionally, our findings resolve the conjecture posed in [Phys. Rev. Lett. 118, 180402(2017)],offering novel insights and potential applications in understanding preparation uncertainties.

关键词： uncertainty relation the tightest uncertainty constants optimal observable sets

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Insights on advanced substrates for controllable fabrication of photoanodes toward efficient and stable photoelectrochemical water splitting

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Carbon Energy 2024年第4期6卷 164-221页

作者： Huilin hou Gang shao Yang Wang Wai‐Yeung Wong Weiyou Yang Institute of Micro/Nano Materials and Devices Ningbo University of TechnologyNingboChina School of Materials Science and Engineering Zhengzhou UniversityZhengzhouChina Department of Applied Biology and Chemical Technology and Research Institute for Smart Energy The Hong Kong Polytechnic UniversityHong KongChina

Conversion of solar energy into H_(2) by photoelectrochemical(PEC)water splitting is recognized as an ideal way to address the growing energy crisis and environmental *** a typical PEC cell,the construction of photoanodes is crucial to guarantee the high efficiency and stability of PEC reactions,which fundamentally rely on rationally designed semiconductors(as the active materials)and substrates(as the current collectors).In this review work,we start with a brief introduction of the roles of substrates in the PEC ***,we provide a systematic overview of representative strategies for the controlled fabrication of photoanodes on rationally designed substrates,including conductive glass,metal,sapphire,silicon,silicon carbide,and flexible ***,some prospects concerning the challenges and research directions in this area are proposed.

关键词： hydrogen photoanode photoelectrochemical substrates water splitting

Boosting oxygen vacancies by modulating the morphology of Au decorated In_(2)O_(3)with enhanced CO_(2)hydrogenation activity to CH_(3)OH

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Journal of Environmental Sciences 2024年第6期140卷 91-102页

作者： Ruxian hou Jiewen xiao Qian Wu Tianyu Zhang Qiang Wang Beijing Key Lab for Source Control Technology of Water Pollution College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China Engineering Research Center for Water Pollution Source Control&Eco-remediation College of Environmental Science and EngineeringBeijing Forestry UniversityBeijing 100083China

CO_(2)hydrogenation to methanol has become one of the most promising ways for CO_(2)utilization,however,the CO_(2)conversion rate and methanol selectivity of this reaction still need to be improved for industrial *** we investigated the structure-activity relationship for CO_(2)conversion to methanol of In_(2)O_(3)-based catalysts by modulating morphology and decorating *** different Au/In_(2)O_(3)catalysts were prepared,their activity follow the sequence of Au/In_(2)O_(3)-nanosphere(Au/In_(2)O_(3)-NS)>Au/In_(2)O_(3)-nanoplate(Au/In_(2)O_(3)-NP)>Au/In_(2)O_(3)-hollow microsphere(Au/In_(2)O_(3)-HM).Au/In_(2)O_(3)-NS exhibited the best performance with good CO_(2)conversion of 12.7%,high methanol selectivity of 59.8%,and large space time yield of 0.32 g CH_(3)OH/(hr·gcat)at 300℃.The high performance of Au/In_(2)O_(3)-NS was considered as the presence of *** contributes to the creation of more surface oxygen vacancies,which further promoted the CO_(2)adsorption and facilitated CO_(2)activation to form the formate intermediates towards *** work clearly suggests that the activity of In_(2)O_(3)catalyst can be effective enhanced by structure engineering and Au decorating.

关键词： CO_(2)hydrogenation Methanol Au/In_(2)O_(3) Morphology Oxygen vacancies

Observing strain glass transition in Ti_(33)Nb_(15)Zr_(25)Hf_(25)O_(2)high entropy alloy with Elinvar effect

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Journal of Materials Science & Technology 2024年第1期168卷 16-23页

作者： Kaichao Zhang Kai Wang Bin Wang Chao Lv Jiaxing Zheng Guanqi Li Yu Fu Wenlong xiao Qingqing Cai Xutao Nie Yingfeng shao Huilong hou Xinqing Zhao School of Materials Science and Engineering Beihang UniversityBeijing 100191China China Aerodynamics Research and Development Center Mianyang 621000China State Key Laboratory of Nonlinear Mechanics Chinese Academy of SciencesInstitute of MechanicsBeijing 100190China Tianmushan Laboratory(Zhejiang Provincial Laboratory for Aviation) Hangzhou 310000China

Exploring the phase transition of high entropy alloys(HEAs)with multiple major elements is of great importance for understanding the underlying physical *** martensitic phase tran-sition has been frequently reported in HEAs,however,nanoscale microstructural phase evolution has not been investigated to the same ***,we have prepared the Ti_(33)Nb_(15)Zr_(25)Hf_(25)O_(2)HEA and investi-gated the strain glass transition and its associated properties using dynamic mechanical analysis and mi-crostructure *** have found that the elastic modulus in Ti_(33)Nb_(15)Zr_(25)Hf_(25)O_(2)HEA deviates from Wachtman’s equation and observed the Elinvar effect in the form of temperature-independent mod-ulus in the temperature range from 150 K to 450 K and frequency-dependence modulus around 220 *** strain glass transition has been evidenced in Ti_(33)Nb_(15)Zr_(25)Hf_(25)O_(2)HEA by the formation and growth of nano-sized domains during in-situ transmission electron microscopy(TEM)cooling,and substantiated by the broken ergodicity during zero-field-cooling/*** strain glass transition is believed to account for the Elinvar effect,where the modulus hardening of nano-sized domains compensates dynam-ically with the modulus softening of the transformable matrix.

关键词： High entropy alloys Strain glass transition Elinvar effect Microstructural evolution Nanodomains

Crystalline-amorphous M@MN_x(M=Co,Fe,Ni)encapsulated in nitrogen-doped carbon for enhanced efficient and durable hydrogen evolution reaction

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Rare Metals 2024年第4期43卷 1547-1556页

作者： Yang Yang xiao-Chuan Duan shao-Hui Guo Xian-Ming Zhang College of Materials Science and Engineering College of ChemistryKey Laboratory of Interface Science and Engineering in Advanced MaterialsTaiyuan University of TechnologyYuci030600China

Developing earth-abundant electrocatalysts for hydrogen evolution reaction(HER)is important for the sustainable energy ***,efficient and stable heterocatalysts consisting of crystalline-amorphous M@MN_(x)(M=Co,Fe,Ni)encapsulated in N-doped carbon layers supported with N-doped graphene sheets(denoted as M@MN_(x)@NC-NG)are synthesized by facile hydrothermal reaction and nitridation *** the nitriding process,metal ions in M(tzbc)_2(H_(2)O)_4(tzbc=4-(1H-1,2,4-triazol-1-yl)benzoic acid)complexes are reduced to crystalline M cores,accompanied by the formation of amorphous MN_(x)shells;the tzbc ligands are insitu carbonized to form outermost N-doped carbon(NC)layers that connect with inner MN_(x)via M-N-C motifs inherited from the complex precursors and inhibit the transition of MN_(x)from amorphous to crystalline *** Co@CoN_(x)@NC-NG catalyst exhibits excellent HER activity with small overpotentials of 45 and 64 mV at a cathode current density of 10 mA·cm^(-2)and low Tafel slopes of 40 and 85 mV·dec^(-1)in 0.5 mol·L^(-1)H_(2)SO_4 and1.0 mol·L^(-1)KOH electrolytes,*** Co@CoN_(x)@NC-NG retains 97%of the initial overpotential after 100,000 s in both acidic and alkaline *** outstanding HER performance originates from the crystalline-amorphous Co@CoN_(x)that redistributes electrons around the heterointerfaces,facilitating the conversion process of H^(+)/H_(2)O to hydrogen and thereby promoting HER *** outermost NC layers serve as the armor of Co@CoN_(x),and graphene nanosheets act as carriers of egg-like Co@CoN_(x)@NC and conduction paths for electron shuttles,ensuring stable and continuous electrocatalytic hydrogen production.

关键词： Hydrogen evolution reaction Electrocatalysts Iron group metals Heterojunction Crystalline-amorphous structure

Genesis and Accumulation of Paleo-Oil Reservoir in Dabei Area,Kuqa Depression,Northwest China:Implications for Tight-Gas Accumulation

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Journal of Earth Science 2024年第2期35卷 655-665页

作者： Fujie Jiang xiao Chen Pengwei Wang Xinghe shao Haijun Yang State Energy Center for Shale Oil Research and Development Beijing102206China National Key Laboratory of Oil and Gas Resources and Engineering Beijing102249China College of Geosciences China University of PetroleumBeijing102249China CNOOC International Ltd. Beijing100027China Research Institute of Petroleum Exploration&Production SINOPECBeijing100083China Research Institute of Petroleum Exploration and Development Tarim OilfieldPetroChinaKorla841000China

Paleo-oil reservoir is of great importance to understand hydrocarbon enrichment mechanism and hydrocarbon exploration potential,but is yet poorly investigated in Kuqa *** occurrence of the paleo-oil reservoir in Dabei area was proved by quantitative grain fluorescence(QGF)and fluid inclusion *** history of the paleo-oil reservoir was reconstructed through:(1)oil-source correlation;(2)time coupling of source rock maturation,porosity evolution and migration *** impact of paleo-oil reservoir on tight-gas accumulation was consequently *** suggest that considerable oil was accumulated in the K_(1)bs reservoir with paleo oil-water contact in Dabei 2 Well and Dabei 201 Well at 5800 and 6040 m,*** oil was primarily sourced from Triassic source rocks with Jurassic source rocks of secondary importance,which was at oil generation window(0.7%–1.1%Ro)during 9–6 and 7.5–5 Ma,*** occurrence of K_(1)bs tight reservoir(porosity<12%)was about 25 Ma,while faults and associated fractures at Kelasue structural belt were developed approximately from 8 to 3.5 ***,the tight oil accumulation was formed during 8–5 *** paleo-oil reservoir in Dabei 1 gas field was destroyed by the evaporation fractionation in later stage.

关键词： Paleo-oil reservoir Dabei area Kuqa Depression Northwest China petroleum geology

Trace Element Mobility in Subducted Marble and Associated Eclogite:Constraints from UHP Rocks in the Shuanghe Area,Central-East China

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Journal of Earth Science 2024年第1期35卷 1-15页

作者： Xingao hou Zhiqiang Yu Shefa Chen Lei Liu Yilin xiao Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring Ministry of EducationSchool of Geosciences and Info-PhysicsCentral South UniversityChangsha 410083China Key Laboratory of Mineralogy and Metallogeny Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China CAS Key Laboratory of Crust-Mantle Materials and Environments School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China

In order to decipher element mobility in UHP meta-sedimentary rocks in the continental subduction zone,major and trace element compositions are investigated for a continuous profile from a representative UHP region in the Dabie *** the lithologic contact zone,contents of K,Ca,LREE,and LILE exhibit varying degrees of downward trends in both marble and eclogite toward the contact zone,indicating that marble and their associated eclogite can release a large amount of K,Ca,and a small number of LILEs and *** is the main Ti phase in both marble and *** rims around rutile can occasionally be seen in *** of Ti and HFSE exhibit a well-coupled relation among marble and eclogite,indicating that substantial Ti and HFSEs were migrated from eclogite to marble,in accord with the capacity of a melt *** and titanites in marble exhibit a relatively limited variation in Nb/Ta ratios(12.9-16.2),similar to those of titanites in eclogite(14.2-16.7),which demonstrates that rutiles and titanites in marble were sourced from eclogite because of short-distance migrations of Ti and *** to the P-T path and the temperature and pressure conditions of the peak metamorphism reported by previous studies,the eclogite associated with marble may not form supercritical fluids in the subduction zone because of the addition of carbonate minerals.

关键词： UHP metamorphism eclogite marble element migration fluid actions geochemistry

Epitaxial growth of borophene on graphene surface towards efficient and broadband photodetector

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Nano Research 2024年第4期17卷 3053-3060页

作者： Zenghui Wu Chen Shifan Zitong Wu Yi Liu Wei shao Xinchao Liang Chuang hou Guoan Tai The State Key Laboratory of Mechanics and Control of Mechanical Structures and Laboratory of Intelligent Nano Materials and Devices of Ministry of Education College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

In-situ integration of multiple materials with well-defined interfaces as heterostructures is of great interest due to their unique properties and potential for new device *** of its polymorphism and diverse bonding geometries,borophene is a promising candidate for two-dimensional heterostructures,but suitable synthesis conditions have limited its potential *** this end,we demonstrate the vertical borophene and graphene heterostructures which form by epitaxial growth of borophene onto multilayer graphene on Cu substrates via chemical vapor deposition,where hydrogen and NaBH_(4) are respectively used as the carrier gas and the boron *** lattice structure of the as-synthesized borophene well coincides with the predictedα′-boron *** borophene-based photodetector shows an excellent broadband photoresponse from the ultraviolet(255 nm)to the infrared(940 nm)wavelengths,with enhanced responsivity compared to pristine borophene or graphene *** work informs emerging efforts to integrate borophene into nanoelectronic applications for both fundamental investigations and technological applications.

关键词： borophene graphene heterostructure photodetector two-dimensional materials