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Construct a 3D microsphere of HMX/B/Al/pTFE to obtain the high energy and combustion reactivity

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Defence Technology（防务技术） 2024年第2期32卷 45-54页

作者： Jian wang Jie Chen Yaofeng Mao Yongjun Deng Wei Cao Fude Nie jun wang institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621999PR China Shock and Vibration of engineering Materials and Structures Key Lab of Sichuan province Mianyang 621010PR China

Metal(aluminum and boron)based energetic materials have been wildly applied in various fields including aerospace,explosives and micro-devices due to their high energy ***,the low combustion efficiency and reactivity of metal fuels,especially boron(B),severely limit their practical ***,multi-component 3D microspheres of HMX/B/Al/pTFE(HBA)have been designed and successfully prepared by emulsion and solvent evaporation method to achieve superior energy and combustion *** reactivity and energy output of HBA are systematically measured by ignitionburning test,constant-volume explosion vessel system and bomb *** to the increased interfacial contact and reaction area,HBA shows higher flame propagation rate,faster pressurization rate and larger combustion heat of 29.95 cm/s,1077 kpa/s,and 6164.43 J/g,which is 1.5 times,3.5 times,and 1.03 times of the physical mixed counterpart(HBA-p).Meanwhile,HBA also shows enhanced energy output and reactivity than 3D microspheres of HMX/B/pTFE(HB)resulting from the high reactivity of *** reaction mechanism of 3D microspheres is comprehensively investigated through combustion emission spectral and thermal analysis(TG-DSC-MS).The superior reactivity and energy of HBA originate from the surface etching of fluorine to the inert shell(Al_(2)O_(3) and B_(2)O_(3))and the initiation effect of Al to *** work offers a promising approach to design and prepare high-performance energetic materials for the practical applications.

关键词： HMX/B/Al/pTFE 3D microspheres Surface etching reaction mechanism

recent progress of in-situ characterization of LiNi_(1−x−y)Co_(x)Mn_(y)O_(2) cathodes for lithium metal batteries: A mini review

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Nano research 2024年第3期17卷 1384-1401页

作者： Huanzhu Lv Xiaoqi Zhu jun Mei Yuanhua Xia Bin wang institute of Fundamental and Frontier Science University of Electronic Science and Technology of ChinaChengdu 611731China Chengdu Development Center of Science and Technology China Academy of Engineering PhysicsChengdu 610200China Key Laboratory of Neutron physics and institute of Nuclear physics and Chemistry China Academy of Engineering Physics(CAEP)Mianyang 621999China

In the context of the gradual popularity of electric vehicles(EVs),the development of lithium battery systems with high energy density and power density is regarded as the foremost way to improve the range of ***_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)cathodes have been the focus of researchers due to their high energy density,excellent power performance,and low-temperature ***,the elaboration of the decay mechanism of NCM cathode based on lithium metal batteries(LMBs)is still being restricted to the primary *** the past decades,the development and application of advanced in-situ characterization tools have facilitated researchers'understanding of the internal operation mechanism of batteries during charging and *** this minireview,the latest progress of in-situ observation of the NCM cathode by X-ray diffraction(XrD),fourier transform infrared(FT-Ir)spectroscopy,raman spectroscopy,atomic force microscopy(AFM),transmission electron microscope(TEM),optical microscope,and other characterization tools is *** mechanisms of structural degradation,cathode-electrolyte interfaces(CEIs)composition,and dynamic changes of NCM,electrolyte breakdown,and gas production are ***,based on the existing research progress,the opportunities and challenges for future in-situ characterization technology in the study of the mechanism of LMBs are discussed in ***,the purpose of this minireview is to summarize recent work that focuses on the outstanding application of in-situ characterization techniques in the mechanistic study of LMBs,and pointing the way to the future development of high energy density and power density LMBs systems.

关键词： lithium metal batteries(LMBs) In-situ characterization LiNi_(1-x-y)Co_(x)Mn_(y)O_(2)(NCM)

Discovering the ultralow thermal conductive A_(2)B_(2)O_(7)-type high-entropy oxides through the hybrid knowle dge-assiste d data-driven machine learning

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Journal of Materials Science & Technology 2024年第1期168卷 131-142页

作者： Ying Zhang Ke ren William Yi wang Xingyu Gao ruihao Yuan jun wang Yiguang wang Haifeng Song Xiubing Liang Jinshan Li State Key Laboratory of Solidification processing Northwestern Polytechnical UniversityXi’an 710072China Innovation Center NPU ChongqingChongqing 401135China institute of Advanced Structure Technology Beijing Institute of TechnologyHaidian DistrictBeijing 100081China Laboratory of Computational physics Institute of Applied Physics and Computational MathematicsBeijing 100088China Defense Innovation institute Academy of Military Sciences of the PLA of ChinaBeijing 100071China

Lattice engineering and distortion have been considered one kind of effective strategies for discovering advanced *** instinct chemical flexibility of high-entropy oxides(HEOs)motivates/accelerates to tailor the target properties through phase transformations and lattice ***,a hybrid knowledge-assisted data-driven machine learning(ML)strategy is utilized to discover the A_(2)B_(2)O_(7)-type HEOs with low thermal conductivity(κ)through 17 rare-earth(rE=Sc,Y,La-Lu)solutes optimized A-site.A designing routine integrating the ML and high throughput first principles has been proposed to predict the key physical parameter(Kpps)correlated to the targetedκof advanced *** the smart-designed 6188(5rE_(0.2))_(2)Zr_(2)O_(7)HEOs,the best candidates are addressed and validated by the princi-ples of severe lattice distortion and local phase transformation,which effectively reduceκby the strong multi-phonon scattering and weak interatomic ***,(Sc_(0.2)Y_(0.2)La_(0.2)Ce_(0.2)pr_(0.2))_(2)Zr_(2)O_(7)with predictedκbelow 1.59 Wm^(−1)K^(−1)is selected to be verified,which matches well with the ex-perimentalκ=1.69 Wm^(−1)K^(−1)at 300 K and could be further decreased to 0.14 Wm^(−1)K^(−1)at 1473 ***,the coupling effects of lattice vibrations and charges on heat transfer are revealed by the cross-validations of various models,indicating that the weak bonds with low electronegativity and few bond-ing charge density and the lattice distortion(r∗)identified by cation radius ratio(r A/r B)should be the Kpps to decreaseκ*** work supports an intelligent designing strategy with limited atomic and electronic Kpps to accelerate the development of advanced multi-component HEOs with proper-ties/performance at multi-scales.

关键词： High-entropy oxides Thermal conductivity pyrochlore Key physical parameter First-principles

Highly red Emissive Conjugated Homopolymers Based on Double B←N Bridged Bipyridine Unit

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Chinese Journal of polymer Science 2024年第8期42卷 1029-1037页

作者： Yu-Yue Gao Kai-Yuan Zhang Shu-Meng wang Hui Tong jun Liu State Key Laboratory of polymer physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and engineering University of Science and Technology of ChinaHefei 230026China

Conjugated homopolymers based on six-member rings,e.g.,polyfluorene,always exhibit blue emission and conjugated homopolymers based on five-member rings,e.g.,polythiophene,can give red emission with low *** this work,we report a series of new conjugated homopolymers based on six-member rings with high-efficiency deep-red *** repeating units of the red light emitting homopolymers are double B←N bridged bipyridine(BNBp)with the boron atoms functionalized with diphenyl,borafluorene,and 2,7-di-tert-butyl-borafluorene groups,*** relationship between the chemical structures and the opto-electronic properties of the monomers and the homopolymers has been systematically *** three polymers emit pure red light(λ_(max)=656 nm)or deep red light(λ_(max)=693 nm)with fluorescence quantum efficiency in solution higher than 60%.The polymers can be used as the emitters in solution-processed organic light-emitting diodes with red emission and decent device *** work indicates a new strategy to design highly efficient light emitting conjugated polymers.

关键词： Conjugated homopolymers Double B←N bridged bipyridine(BNBp) Deep-red emission High fluorescent efficiency

Unveiling optical anisotropy in disrupted symmetry WSe2/Sip heterostructures

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Nano research 2024年第9期17卷 8585-8591页

作者： Biqi Hu Xing Xie Xinyu Ouyang junying Chen Shaofei Li jun He Zongwen Liu Jian-Tao wang Yanping Liu institute of Quantum physics School of PhysicsCentral South University932 South Lushan RoadChangsha 410083China State Key Laboratory of precision Manufacturing for Extreme Service performance Central South University932 South Lushan RoadChangsha 410083China School of Chemical and Biomolecular engineering The University of SydneyNSW 2006Australia The University of Sydney Nano institute The University of SydneyNSW 2006Australia Beijing National Laboratory for Condensed Matter physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of physical Sciences University of Chinese Academy of SciencesBeijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China Shenzhen research institute of Central South University Shenzhen 518000China

Two-dimensional(2D)transition metal dichalcogenides(TMDs)have garnered considerable attention for their promising applications in sensors and optoelectronic devices,owing to their exceptional optical,electronic,and optoelectronic ***,the inherent high symmetry of TMD lattices imposes limitations on their functional ***,we present a strategy to disrupt the C_(3)rotational symmetry of monolayer WSe_(2)by fabricating a heterostructure incorporating WSe_(2)and Sip *** comprehensive experimental investigations and first-principle calculations,we elucidate that in the WSe_(2)/Sip heterostructure,excitons-both neutral and charged-emanating from WSe_(2)exhibit pronounced anisotropy,which remains robust against temperature ***,we observe an anisotropic ratio reaching up to 1.5,indicating a substantial degree of ***,we demonstrate the tunability of exciton anisotropy through the application of a magnetic field,resulting in a significant reduction in the anisotropic ratio with increasing field strength,from 1.57 to ***,the change in heterojunction anisotropy ratio reaches 24.8%as the magnetic field *** findings elucidate that the perturbation of the C_(3)rotational symmetry of the WSe_(2)monolayer arises from a non-uniform charge density distribution within the layer,exhibiting mirror *** results underscore the potential of heterostructure engineering in tailoring the properties of isotropic materials and provide a promising avenue for advancing the application of anisotropic devices across various fields.

关键词： symmetry breaking heterostructure engineering anisotropy optical spectroscopy

HIGH rESOLUTION pArAMETrIC MODELLING FOr TWO-DIMENSIONAL rADAr TArGET USING prONY ALGOrITHM

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Journal of electronics(china) 2000年第1期17卷 38-45页

作者： wang jun (institute of electronic engineering, Chinese academy of engineering and physics, mianyang 621900)

On the conditions of low-resolution radar, a parametric model for two-dimensional radar target is described here according to the theory of electromagnetic scattering and the geometrical theory of diffraction. A high resolution estimation algorithm to extract the model parameters is also developed by building the relation of the scattering model and prony model. The analysis of Cramer-rao bound and simulation show that the method here has better statistical performance. The simulated analysis also indicates that the accurate extraction of the diffraction coefficient of scattering center is restricted by signal to noise ratio, radar center frequency and radar bandwidth.

关键词： Two-dimensional radar Scattering center attributes parametric modelling prony algorithm resolution

Theoretical study of ZnO adsorption and bonding on Al_2O_3(0001) surface

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Science china(physics,Mechanics & Astronomy) 2004年第6期47卷 664-675页

作者： LI Yanrong1,YANG Chun1,2,XUE Weidong1,LI Jinshan3 & LIU Yonghua3 1.institute of Microelectronics and Solid State electronics,University of electronic Science and Technol- ogy of china,Chengdu 610054,china 2.institute of Mathematics and Software Science,Sichuan Normal University,Chengdu 610068,china 3.institute of Chemical Materials,china academy of engineering physics,mianyang 621000,china institute of Microelectronics and Solid State electronics University of Electronic Science and Technology of China Chengdu 610054 China institute of Mathematics and Software Science Sichuan Normal University Chengdu 610068 China institute of Chemical Materials China Academy of Engineering Physics Mianyang 621000 China

ZnO adsorption on sapphire (0001) surface is theoretically calculated by using a plane wave ultrasoft pseudo-potential method based on ab initio molecular dynamics. The results reveal that the surface relaxation in the first layer Al-O is reduced, even eliminated after the surface adsorption of ZnO, and the chemical bonding energy is 434.3(±38.6) kJ·mol?1. The chemical bond of ZnO (0.185 ± 0.01 nm) has a 30° angle away from the adjacent Al-O bond, and the stable chemical adsorption position of the Zn is deflected from the surface O-hexagonal symmetry with an angle of about 30°. The analysis of the atomic populations, density of state and bonding electronic density before and after the adsorption indicates that the chemical bond formed by the O2 of the ZnO ? and the surface Al3+ has a strong ionic bonding characteristic, while the chemical bond formed by the Zn2+ and the surface O2 has an obvious covalent characteristic, which ? comes mainly from the hybridization of the Zn 4s and the O 2p and partially from that of the Zn 3d and the O 2p.

关键词： -Al2O3 (0001 ) ZnO ab initio 分子的动力学化学吸附状态的密度

electronic structure and magnetism of r(Fe,Si)_(12) (r=Y,Nd)

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Science china(physics,Mechanics & Astronomy) 2006年第2期49卷 195-202页

作者： SUN Guang’ai1, CHEN Bo1, DU Honglin2, FAN Zhijian1, GAO Tao3 & QI Xinhua31. institute of Nuclear physics and Chemistry, china academy of engineering physics, mianyang 621900, china 2. Department of physics, peking university, Beijing 100871, china 3. institute of Atomic and Molecular physics, Sichuan University, Chengdu 610065, china institute of Nuclear physics and Chemistry China Academy of Engineering Physics Mianyang China Department of physics Peking university Beijing China institute of Atomic and Molecular physics Sichuan University Chengdu China

The newly developed full-potential linearized augmented plane wave (LApW) and local orbitals (lo) based on standard ApW methods are briefly introduced, and the structure and magnetic properties of r(Fe, Si)12 compounds (r = Y, Nd) are calculated using the method. The distribution of Si at different sites is analyzed based on total energy of one crystal unit with structure having been optimized. The characters of magnetic mo-ments, total density of states (TDOS) and partial density of states (pDOS) for different crystal sites Si occupies are obtained and analyzed. The results show that the total mag-netic moments of rFe10Si2 (r = Y, Nd) are larger than those of rFe10M2 (M = Ti, V, Cr, Mn, Mo and W) and the hybridization mechanism is seen as follows. Si(8j) reduce the mag-netic moments of Fe at three sites, however, Si(8f) mainly reduce the magnetic moments of Fe(8i) and Fe(8j) atoms. The Curie temperature is markedly enhanced by the introduc-tion of Si atoms according to spin fluctuation of DOS at Fermi level.

关键词： (L)ApW+lo method r(Fe Si)12(r = Y Nd) magnetic moment Density of state.

Boost VS_(2) electrochemical reactive kinetics by regulating crystallographic planes and coupling carbon matrix for high performance sodium-ion storage

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rare Metals 2024年第1期43卷 98-112页

作者： Min Zeng Ming-Shan wang Lin Chen En-Zhi Li Zhen-Liang Yang Dan Zhou Hai-Jiao Xie jun-Chen Chen Zhi-Yuan Ma Bing-Shu Guo Bo Yu Xing Li School of New Energy and Materials Southwest Petroleum UniversityChengdu 610500China Energy Storage research institute Southwest Petroleum UniversityChengdu 610500China institute of Materials China Academy of Engineering PhysicsMianyang 621908China Beijing Advanced Innovation Center for Materials Genome engineering University of Science and TechnologyBeijingBeijing 100083China Hangzhou Yanqu Information Technology Co. Ltd.Hangzhou 310003China

Vanadium disulfide(VS_(2)) as a typical two-dimensional transition metal chalcogenide has excellent competitiveness for sodium-ion storage due to its wide layer spacing(0.575 nm),high theoretical capacity of 932mAh·g^(-1) originating from multi-electron electrochemical ***,continuous sodiation process accompanied by crystal structural evolution and collapse cause rapid capacity ***,novel few-layer VS_(2)nanosheets with open(001) crystal planes are in-situ constructed on reduced graphene oxide to solve these issues mentioned *** indicates that few-layer VS_(2)provides more Na^(+) storage activity due to the low Na^(+)surface migration energy barrier on exposed crystal(001)*** flexible and high electronic conductivity of carbon matrix also effectively builds multi-level buffer structure and electron transport kinetics to boost the Na^(+)insertion/conversion reactive activity on VS_(2) as well as Na^(+) pseudocapacitance storage kinetics on edges and defects of nano *** coupling effects result in high rate capability and long cycling stability as a battery/capacitor *** delivers conspicuous high energy density of 81 and 40 Wh·kg^(-1) at power density of 118 and 10,286W·kg^(-1),as well as 80% energy retention rate after 5000cycles,confirming its great application potential in sodiumbased storage devices.

关键词： Vanadium disulfide reduced graphene oxide Anode Sodium-ion battery Sodium-ion capacitor