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Estimating energy release performance of oxidizer-activated aluminum fuel particles under ultrafast stimulus

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Defence Technology（防务技术） 2023年第5期23卷 92-99页

作者： Ya-ru Li Hui Ren xin-zhou wu Hui-xin Wang Xi-long Yu State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China State Key Laboratory of High Temperature Gas Dynamics Institute of MechanicsChinese Academy of SciencesBeijing100190China

Aluminum(Al) particles are good fuel additives to improve the energy output performances of explosives. Under detonation environment, reaction delay of Al particles plays a key role in the energy release efficiency. Up to date, reaction delay of Al particles is still limited by the efficiency of mass and heat transfer from oxidizers to Al particles. To address this issue, a homogeneous fuel-oxidizer assembly has recently become a promising strategy. In this work, oxidizer-activated Al fuel particles(ALG) were prepared with glycidyl azide polymer(GAP) as the oxidizer. The ALG was in uniform spherical shape and core-shell structure with shell layer of around 5 nm which was observed by scanning electron microscope and transmission electron microscope. The localized nanoscale mid-IR measurement detected the uniform distribution of characteristic absorption bond of GAP in the shell layer which confirmed the homogenous fuel-oxidizer structure of ALG. A thermal gravimetric analysis of ALG at ultrafast heating rate of 1000℃/min under argon atmosphere was conducted. The decomposition of GAP finished much earlier than that of GAP at heating rate of 10℃/min. Under ultrafast high laser fluence, the reaction response of ALG was characterized and compared with that of micro-sized Al(μAl). With the increase of laser energy, the propagation distance of the shock wave increased. However, the velocity histories were nearly the same when energies were lower than 299 mJ or higher than 706 mJ. The propagation distance of the shock wave for ALG was 0.5 mm larger than that for μAl at 2.1 μs. The underwater explosion showed the peak pressure and the shock wave energy of the ALG-based explosive were both higher than those of the μAl-based explosive at 2.5 m. This study shows the feasibility to improve the energy release of Al-based explosives via using the oxidizer-activated Al fuel particles with energetic polymer as the oxidizer.

关键词： Aluminum Glycidyl azide polymer Laser Detonation Explosive Ultrafast stimulus

Novel aluminum-based fuel:Facile preparation to improve thermal reactions

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Defence Technology（防务技术） 2022年第10期18卷 1852-1862页

作者： Fa-yang Guan Hui Ren Wan-jun Zhao xin-zhou wu Qing-jie Jiao State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

To improve the thermal properties of aluminum(Al)in the energetic system,a coated structure with ammonium perchlorate(AP)was prepared by a facile *** N,N-Dimethylformamide(DMF)was chosen as an ideal solvent based on heterogeneous nucleation theory and molecular dynamics *** coated structure could enlarge the contact area and improve the reaction environment to enhance the thermal *** addition of AP could accelerate oxidation temperature of Al with around 17.5°*** the heat release of 85@15 composition rises to 26.13 k J/g and the reaction degree is97.6%with higher peak pressure(254.6 k Pa)and rise rate(1.397 MPa/s).An ideal ratio with 15 wt%AP was probed *** high energy laser-induced shockwave experiment was utilized to simulate the reaction behavior in hot *** the larger activated mixture of coated powder could release more energy to promote the growth of shockwave with higher speed up to 518.7±55.9 m/*** conclusion,85@15 composition is expected to be applied in energetic system as a novel metal fuel.

关键词： Aluminum-based fuel Heterogeneous nucleation Molecular dynamics simulation Thermal reaction High energy laser-induced shockwave experiment

Phase Behavior of Liquid Crystals Formed in [C12mim]CI/H2O and [C12mim] Cl/Alcohols Systems

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Chinese Journal of Chemical Physics 2009年第5期22卷 453-459,I0001页

作者： Mei-shan Pei Zhi-yan wu Lu-yan Wang xin-zhou wu Xu-tang Tao School of Chemistry and Chemical Engineering University of Jinan Ji'nan 250022 China State Key Laboratory of Crystal Material Shandong University Ji'nan 250100 China

Phase behaviors of different binary systems involving 1-dodecyl-3-methylimidazolium chlo- ride （[C12mim]Cl） and H20, [C12mim]Cl and different alcohols （1-butanol, 1-pentanol, 1- hexanol and 1-octanol） are investigated at 25 ℃. Hexagonal liquid crystal phase （H1） is identified in [C12mim]Cl/H2O system, and lamellar liquid-crystalline （Lα） phase is found in [C12mim]Cl/alcohols systems by using polarized optical microscopy and small-angle X-ray scattering techniques. The formation of such phases is considered as a synergetic result of the solvatophobic force and the hydrogen-bonded network comprising an imidazoliuin ring, chloride ion and water （or alcohols）, which can be confirmed by Fourier transform infrared spectra. It is noticeable that in [C12mim]Cl/1-octanol system, the lattice spacings of lamellar phase increase with increasing C12mimCl concentration, which is opposite to the results of [C12mim]Cl/H2O system. This may result mainly from stronger static repulsion among hydrophilic headgroups of imidazolium salts arranged in the bilayers of lamellar structures. Further measurements by differential scanning calorimetry indicate that the lamellar phase is stable within a wide temperature range above room temperature. However, the lattice spacings decrease with the increase of temperature, which may. be due to the softening of the hydrocarbon chain of [C12mim]Cl molecules. In different alcohols systems, it is found that the lamellar lyotropic liquid crystal structure is easier to be formed when the carbon chain length becomes longer.

关键词： 1-dodecyl-3-methylimidazolium chloride Lyotropic liquid crystal Differentialscanning calorimetry Small-angle X-ray scattering

Dissolution kinetics and reaction mechanism of Al_(2)O_(3) in molten CaF_(2)-CaO-Al_(2)O_(3) slag

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Journal of Iron and Steel Research International 2024年第4期31卷 861-869页

作者： Yao-xin Du Yan-wu Dong zhou-hua Jiang Ganna Stovpchenko Yu-shuo Li Jun Huang xin-wei Wang Yu-xiao Liu School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina Key Laboratory of Ecological Metallurgy of Multimetallic Mineral Northeastern UniversityShenyang 110819LiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina E.O.Paton Electric Welding Institute of the National Academy of Science of Ukraine Kiev 03115Ukraine

The dissolution behavior of Al_(2)O_(3) in molten CaF_(2)-CaO-Al_(2)O_(3) slag,a basic slag system of electroslag remelting process,was investigated by rotating cylinder method using corundum rods to simulate Al_(2)O_(3) inclusions in *** experimental results show that the dissolution rate of Al_(2)O_(3);rods in CaF_(2)-CaO-Al_(2)O_(3) slag increases with the increase in rotating speed and temperature,and the rate-controlling step is the mass transfer in the *** dissolution rate of Al_(2)O,in CaF_(2)-CaO-Al_(2)O_(3) slag increases with the increase in the ratio of CaO to Al_(2)O_(3),which is due to the increase in dissolution driving force and the decrease in slag *** apparent activation energy of the mass transfer of AlOs in slag C is calculated to be 222.86 kJ mol^(-1).During the dissolution of Al_(2)0,inclusions in the slag,it reacts with F in liquid slag at first,then reacts with CaO to form the intermediate compounds of xCaO-yAl_(2)O_(3) system,and finally dissolves in molten *** dissolution rate of Al_(2)O_(3) inclusions in CaF_(2)-CaO-Al_(2)O_(3) slag for electroslag remelting is positively correlated with the ratio of the dissolution driving force and slag viscosity,and the correlation coeficient is 2.487×10^(-11).

关键词： Inclusion Electroslag remelting Mass transfer:Dissolution rate-Dissolution driving force

Principal components of nuclear mass models

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 65-71页

作者： xin-Hui wu Pengwei Zhao Department of Physics Fuzhou UniversityFuzhou 350108China State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China

Principal component analysis(PCA)is employed to extract the principal components(PCs)present in nuclear mass models for the first *** effects from different nuclear mass models are reintegrated and reorganized in the extracted *** PCs are recombined to build new mass models,which achieve better accuracy than the original theoretical mass *** comparison indicates that using the PCA approach,the effects contained in different mass models can be collaborated to improve nuclear mass predictions.

关键词： nuclear mass principal component analysis nuclear models statistical methods

Potential effects of aerosol generation and transmission during bedside endoscope cleaning

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第7期25卷 628-632页

作者： Tingting SHENG xin wu Li CEN Ye LU Chenying zhou Qing GU Nursing Department the First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China Department of Gastroenterology the First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China Zhejiang Provincial Center for Disease Control and Prevention Hangzhou 310051China

Airborne transmission is among the most frequent types of nosocomial *** years have witnessed frequent outbreaks of airborne diseases,such as severe acute respiratory syndrome(SARS)in 2002,Middle East respiratory syndrome(MERS)in 2012,and coronavirus disease 2019(COVID-19),with the latter being on the rampage since the end of 2019 and bringing the effect of aerosols on health back to the fore(Gralton et al.,2011;Wang et al.,2021).An increasing number of studies have shown that certain highly transmissible pathogens can maintain long-term stability and efficiently spread through aerosols(Leung,2021;Lv et al.,2021).As reported previously,influenza viruses that can spread efficiently through aerosols remain stable for a longer period compared to those that *** World Health Organization(WHO)has stated that aerosol-generating procedures(AGPs)play an important role in aerosol transmission in hospitals(Calderwood et al.,2021).AGPs,referring to medical procedures that produce aerosols,including dental procedures,endotracheal intubation,sputum aspiration,and laparoscopic surgeries,have been reported to be significantly associated with an increased risk of nosocomial infection among medical personnel(Hamilton,2021).

关键词： Endoscopy Endoscopic surgery Aerosol transmission Bedside endoscope precleaning

Copper-catalyzed enantioselective desymmetrizing C(sp^(2))-H functionalization of azide-ynamides via α-imino copper carbenes

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Science China Chemistry 2024年第9期67卷 2982-2988页

作者： En-He Huang Li-Gao Liu You-Wei Yin Hao-Xuan Dong Ji-Jia zhou xin Lu Bo zhou Long-wu Ye Key Laboratory for Chemical Biology of Fujian Province and State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

α-Imino metal carbenes are versatile intermediates in organic synthesis,and have broad applications in the assembly of divergent ***,the catalytic enantioselective desymmetrization based onα-imino metal carbenes has not been developed to ***,we disclose an enantioselective desymmetrizing C(sp^(2))-H functionalization of azide-ynamides viaα-imino copper carbenes,leading to the efficient assembly of divergent chiral indoloazepines in generally moderate to excellent yields with high ***,this reaction represents the first enantioselective desymmetrization based onα-imino metal *** synthetic transformations and biological tests show the potential utility of this ***,computational studies are employed to elucidate the reaction mechanism and the origin of enantioselectivity.

关键词： enantioselective desymmetrization metal carbenes copper catalysis nitrene transfer alkynes

Role of alloying and heat treatment on microstructure and mechanical properties of cast Al-Li alloys:A review

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China Foundry 2024年第5期21卷 445-460页

作者： Guo-hua wu You-jie Guo Fang-zhou Qi Shen Zhang Yi-xiao Wang xin Tong Liang Zhang School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Due to the prominent advantages of low density,high elastic modulus,high specific strength and specific stiffness,cast Al-Li alloys are suitable metallic materials for manufacturing complex large-sized components and are ideal structural materials for aerospace,defense and military *** the basis of the microstructural characteristics of cast Al-Li alloys,exploring the role of alloying and micro-alloying can stabilize their dominant position and further expand their application *** this review,the development progress of cast Al-Li alloys was summarized *** to the latest research highlights,the influence of alloying and heat treatment on the microstructure and mechanical properties was systematically *** potential methods to improve the alloy performance were *** response to the practical engineering requirements of cast Al-Li alloys,the scientific challenges and future research directions were discussed and prospected.

关键词： cast Al-Li alloy alloying microstructure mechanical properties heat treatment

Dissipation-Driven Superradiant Phase Transition of a Two-Dimensional Bose-Einstein Condensate in a Double Cavity

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Chinese Physics Letters 2024年第6期41卷 44-48页

作者： Bo-Hao wu xin-xin Yang Yu Chen Wei Zhang Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of ChinaBeijing 100872China Key Laboratory of Quantum State Construction and Manipulation(Ministry of Education) Renmin University of ChinaBeijing 100872China Graduate School of China Academy of Engineering Physics Beijing 100193China Beijing Academy of Quantum Information Sciences Beijing 100193China

We study superradiant phase transitions in a hybrid system of a two-dimensional Bose–Einstein condensate of atoms and two cavities arranged with a tilt *** adjusting the loss rate of cavities,we map out the phase diagram of steady states within a mean field *** is found that when the loss rates of the two cavities are different,superradiant transitions may not occur at the same time in the two cavities.A first-order phase transition is observed between the states with only one cavity in superradiance and both in *** the case that both cavities are superradiant,a net photon current is observed flowing from the cavity with small decay rate to the one with large decay *** photon current shows a non-monotonic dependence on the loss rate difference,owing to the competition of photon number difference and cavity field phase *** findings can be realized and detected in experiments.

关键词： Einstein transitions decay