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Reactive molecular dynamics insight into the thermal decomposition mechanism of 2,6-Bis(picrylamino)-3,5-dinitropyridine

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Defence technology（防务技术） 2024年第3期33卷 134-146页

作者： Jianbo Fu Hui Ren Xinzhou Wu Yongjin Chen Mi Zhang Yazhi Cheng State Key Laboratory of Explosion Science and technology Beijing Institute of TechnologyBeijing 100081China

2,6-bis(picrylamino)-3,5-dinitropyridine(PYX)has excellent thermostability,which makes its thermal decomposition mechanism receive much *** this paper,the mechanism of PYX thermal decomposition was investigated thoroughly by the ReaxFF-lg force field combined with DFT-B3LYP(6-311++G)*** detailed decomposition mechanism,small-molecule product evolution,and cluster evolution of PYX were mainly *** the initial stage of decomposition,the intramolecular hydrogen transfer reaction and the formation of dimerized clusters are earlier than the denitration *** the progress of the reaction,one side of the bitter amino group is removed from the pyridine ring,and then the pyridine ring is *** final products produced in the thermal decomposition process are CO_(2),H_(2)O,N_(2),and H_(2).Among them,H_(2)O has the earliest generation time,and the reaction rate constant(k_(3))is the *** clusters are formed during the decomposition of PYX,and the formation,aggregation,and decomposition of these clusters are strongly affected by *** low temperatures(2500 K-2750 K),many clusters are *** high temperatures(2750 K-3250 K),the clusters aggregate to form larger *** 3500 K,the large clusters decompose and become *** the late stage of the reaction,H and N in the clusters escaped almost entirely,but more O was trapped in the clusters,which affected the auto-oxidation process of ***'s initial decomposition activation energy(E_(a))was calculated to be 126.58 kJ/*** work contributes to a theoretical understanding of PYX's entire thermal decomposition process.

关键词： PYX Thermal decomposition ReaxFF-lg MD simulations Excellent thermostable explosives

Propagation Properties of Shock Waves in Polyurethane Foam based on Atomistic Simulations

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Defence technology（防务技术） 2024年第1期31卷 117-129页

作者： Zhiqiang Hu Jianli Shao Shiyu Jia Weidong Song Cheng Wang State Key Laboratory of Explosion Science and technology Beijing Institute of TechnologyBeijing 100081China

Porous materials are widely used in the field of protection because of their excellent energy absorption *** this work,a series of polyurethane microscopic models are established and the effect of porosity on the shock waves is studied with classical molecular dynamics ***,shock Hugoniot relations for different porosities are obtained,which compare well with the experimental *** pores collapse and form local stress wave,which results in the complex multi-wave structure of the shock *** microstructure analysis shows that the local stress increases and the local velocity decreases gradually during the process of pore collapse to complete ***,it leads to stress relaxation and velocity *** shock stress peaks can be fitted with two exponential functions,and the amplitude of attenuation coefficient decreases with the increase of ***,the pore collapse under shock or non-shock are discussed by the entropy increase rate of the *** energy is dissipated mainly through the multiple interactions of the waves under *** energy is dissipated mainly by the friction between atoms under non-shock.

关键词： Polyurethane foam Shock wave Attenuation Atomistic simulation

Assessing the energy release characteristics during the middle detonation reaction stage of aluminized explosives

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Defence technology（防务技术） 2024年第3期33卷 270-277页

作者： Kun Yang Lang Chen Danyang Liu Bin Zhang Jianying Lu Junying Wu State Key Laboratory of Explosion Science and technology Beijing Institute of TechnologyBeijing 100081China

Afterburning behind the detonation front of an aluminized explosive releases energy on the millisecond timescale,which prolong the release of detonation energy and the energy release at different stages also shows significant ***,at present,there are few effective methods for evaluating the energy release characteristics of the middle reaction stage of such explosives,which can have a duration of tens to hundreds of *** present work demonstrates an approach to assessing the midstage of an aluminized explosive detonation based on a water push test employing a high degree of *** this method,the explosive is contained in a steel cylinder having one end closed that is installed at the bottom of a transparent water *** detonation,the gaseous products expand in one direction while forcing water ahead of *** resulting underwater shock wave and the interface between the gas phase products and the water are tracked using an ultra-high-speed framing and streak *** shock wave velocity in water and the expansion work performed by the gaseous detonation products were calculated to assess the energy release characteristics of aluminized explosives such as CL-20 and RDX in the middle stage of the detonation *** the middle stage of the detonation process of these aluminized explosives,the aluminum reaction reduced the attenuation of shock waves and increased the work performed by gas phase products.A higher aluminum content increased the energy output while the presence of oxidants slowed the energy release *** work demonstrates an effective means of evaluating the performance of aluminized explosives.

关键词： Aluminized explosive Non-ideal detonation Water push test Energy release

Enhanced structural damage behavior of liquid-filled tank by reactive material projectile impact

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Defence technology（防务技术） 2024年第1期31卷 211-229页

作者： Jianwen Xie Yuanfeng Zheng Zhenyang Liu Chengzhe Liu Aoxin Liu Pengwan Chen Haifu Wang State Key Laboratory of Explosion Science and technology Beijing Institute of TechnologyBeijing 100081China

A series of ballistic experiments were performed to investigate the damage behavior of high velocity reactive material projectiles(RMPs) impacting liquid-filled tanks,and the corresponding hydrodynamic ram(HRAM) was studied in ***/Al/W RMPs with steel-like and aluminum-like densities were prepared by a pressing/sintering *** projectiles impacted a liquid-filled steel tank with front aluminum panel at approximately 1250 m/*** corresponding cavity evolution characteristics and HRAM pressure were recorded by high-speed camera and pressure acquisition system,and further compared to those of steel and aluminum *** different from the conical cavity formed by the inert metal projectile,the cavity formed by the RMP appeared as an ellipsoid with a conical *** RMPs were demonstrated to enhance the radial growth velocity of cavity,the global HRAM pressure amplitude and the front panel damage,indicating the enhanced HRAM and structural damage ***,combining the impact-induced fragmentation and deflagration characteristics,the cavity evolution of RMPs under the combined effect of kinetic energy impact and chemical energy release was *** mechanism of enhanced HRAM pressure induced by the RMPs was further revealed based on the theoretical model of the initial impact wave and the impulse ***,the linear correlation between the deformation-thickness ratio and the non-dimensional impulse for the front panel was obtained and *** was determined that the enhanced near-field impulse induced by the RMPs was the dominant reason for the enhanced structural damage behavior.

关键词： Reactive material projectile Hydrodynamic ram Enhanced structural damage Liquid-filled tank Impact

Phylogenetic study on Scenedesmacae with the description of a new genus Coccoidesmus ***.(Chlorophyceae,Chlorophyta)and chloroplast genome analyses

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Journal of Oceanology and Limnology 2024年第4期42卷 1272-1285页

作者： Qinghua WANG Ying HOU Yanhui LI Ying SHI Guoxiang LIU College of Biological Sciences and technology Taiyuan Normal UniversityJinzhong 030619China Shanxi Vocational University of Engineering Science and technology Jinzhong 030619China Key Laboratory of Algal biology Institute of HydrobiologyChinese Academy of SciencesWuhan 430072China

Members of the family Scenedesmaceae are some of the most common algal taxa in inland ecosystems,and they are widely distributed in freshwaters,aerial,and sub-aerial *** the continuous updating of methods,the classic morphological taxonomy of this family needs to be *** recent years,many genera of Scenedesmaceae have been established via the use of molecular *** phylogenetic relationships within Scenedesmaceae were analyzed using different molecular markers and morphological data,and the new freshwater genus Coccoidesmus Wang,Hou et Liu *** *** new species in this genus were also *** analysis based on tufA genes revealed that the new genus formed an independent clade closely related to ***,these two genera are characterized by significant morphological differences in colony arrangement and cell *** chloroplast genome of the type species was assembled and annotated,and analyses of genome structure and sequences were *** genome data could help clarify the phylogenetic relationships within this family.

关键词： phylogenetic Scenedesmaceae Coccoidesmus morphology chloroplast genome

On equivalence of state-based potential games

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Science China(Information Sciences) 2024年第6期67卷 313-327页

作者： Han WU Jinhuan WANG institute of Mathematics School of ScienceHebei University of Technology

In this paper, we explore state-based potential games using the semi-tensor product of ***, applying the potential equation, we derive both a necessary and sufficient condition as well as a sufficient condition to verify whether a state-based game qualifies as a potential game. Next, we present two static equivalence conditions of state-based potential games. We then delve into dynamic equivalence. We propose a criterion that allows us to identify state-based games that are dynamically equivalent to state-based potential games and share similar dynamic properties. Ultimately, we introduce the concept of state-based networked evolutionary games. We provide a necessary and sufficient condition to ensure that a state-based networked evolutionary game can be classified as a state-based potential game.

关键词： semi-tensor product of matrices state-based potential game verification equivalence state-based networked evolutionary game

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Numerical analysis of moving train induced vibrations on tunnel,surrounding ground and structure

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 179-192页

作者： Swati Srivastav Sowmiya Chawla Swapnil Mishra Department of Applied Geophysics Indian Institute of Technology(ISM)Dhanbad 826004India Department of Civil Engineering Indian Institute of Technology(ISM)Dhanbad 826004India Department of Mining Engineering Indian Institute of Technology(ISM)Dhanbad 826004India

This study is focused on the effect of vibration induced by moving trains in tunnels on the surrounding ground and structures.A three-dimensional finite element model is established for a one-track railway tunnel and an adjacent twelve-storey building frame by using commercial software Midas GTS-NX(2019)and Midas *** study considered the moving load effect of a complete train,which varies with space as well as with *** effect of factors such as train speed,overburden pressure on the tunnel and variation in soil properties are studied in the time *** a result,the variations in horizontal and vertical acceleration for two different sites,i.e.,the free ground surface(without structure)and the area containing the structure,are ***,the displacement pattern of the raft foundation is plotted for different train *** lower speeds,the heaving phenomenon is negligible,but as the speed increases,both the heaving and differential settlement increase in the *** study demonstrates that the effect of moving train vibrations should be considered in the design of new nearby structures and proper ground improvement should be considered for existing structures.

关键词： moving train load tunnels vibration effect finite element method(FEM) wave propagation

Identification and functional analysis of CG3526 in spermatogenesis of Drosophila melanogaster

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Insect Science 2024年第1期31卷 79-90页

作者： Qihao Hu Yanhong Xiao Runnan Wei Ting Tang Liang Wen Yuzhen Lu Xiao-Qiang Yu Guangdong Provincial Key Laboratory of Insect Developmental biology and Applied technology Guangzhou Key Laboratory of Insect Development Regulation and Application ResearchInstitute of Insect Science and TechnologySchool of Life SciencesSouth China Normal UniversityGuangzhou510631 China

Spermatogenesis is a critical part of reproduction in insects;however,its molecular mechanism is still largely *** this study,we identified a testis-specific gene CG3526 in Drosophila *** analysis showed that CG3526 contains a zinc binding domain and 2 C2H2 type zinc fingers,and it is clustered to the vertebrate really interesting new gene(RING)family E3 ubiquitin-protein *** CG3526 was knocked down by RNA interference(RNAi),the testis became much smaller in size,and the apical tip exhibited a sharp and thin end instead of the blunt and round shape in the control *** importantly,compared to the control flies,only a few mature sperm were present in the seminal vesicle of C587-Gal4>CG3526 RNAi *** staining of the testis from CG3526 RNAi flies showed that the homeostasis of testis stem cell niche was disrupted,cell distribution in the apical tip was scattered,and the process of spermatogenesis was not ***,we found that the phenotype of CG3526 RNAi flies’testis was similar to that of testis of Stat92E RNAi flies,the expression level of CG3526 was significantly downregulated in the Stat92EF06346 mutant flies,and the promoter activity of CG3526 was upregulated by *** together,our results indicated that CG3526 is a downstream effector gene in the JAK-STAT signaling pathway that plays a key role in the spermatogenesis of Drosophila.

关键词： CG3526 JAK-STAT spermatogenesis STAT92E testis

Investigation of oxy-fuel combustion for methane and acid gas in a diffusion flame

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Chinese Journal of Chemical Engineering 2024年第1期65卷 106-116页

作者： Songling Guo Xun Tao Fan Zhou Mengyan Yu Yufan Wu Yunfei Gao Lu Ding Fuchen Wang institute of Clean Coal technology East China University of Science and TechnologyShanghai 200237China

Co-combustion of methane(CH4)and acid gas(AG)is required to sustain the temperature in Claus reaction *** this study,oxy-fuel combustion of methane and acid gas has been experimentally studied in a diffusion *** equivalence ratios(ER=1.0,1.5,2.0)and CH_(4)-addition ratios(CH_(4)/AG=0.3,0.5,0.7)were examined and the flame was interpreted by analyzing the distributions of the temperature and species concentration along central ***_(4)-AG diffusion flame could be classified into three sections namely initial reaction,oxidation and complex reaction *** oxidation of CH_(4)and H_(2)S was noted in the first section wherein H_(2)S was preferred and both were mainly proceeding decomposition and partial ***_(2)was formed at oxidation section together with obvious presence of H2 and ***,H2 and CO were inclined to be sustained under fuel rich condition in the complex reaction *** ER and increasing CH4/AG contributed to higher temperature,H_(2)S and CH_(4)oxidation and CO_(2)*** a growing trend for CH_(4)and AG to convert into H_(2),CO and SO_(2)could be *** this factor enhanced the generation of CS2 and COS in the flame inner core by interactions of CH4 and CO_(2)with sulfur *** was formed through the interactions of CO and CO_(2)with sulfur *** CS_(2)production directly relied on reaction of CH_(4)with sulfur *** concentration of COS was greater than CS_(2)since CS_(2)was probably inhibited due to the presence of H_(2).COS and CS_(2)could be consumed by further oxidation or other complex reactions.

关键词： Acid gas Methane Oxy-fuel combustion Oxidation Chemical analysis Carbon sulfides