Ammonium dinitramide(ADN),which has the advantages of high energy density,no halogen and low characteristic signal,is not only considered as a new high-energy oxidizer that is expected to replace the traditional oxidi...Ammonium dinitramide(ADN),which has the advantages of high energy density,no halogen and low characteristic signal,is not only considered as a new high-energy oxidizer that is expected to replace the traditional oxidizer ammonium perchlorate(AP)in solid propellants,but also a good performance explosive in itself.However,due to the strong hygroscopicity of ADN,its application in solid propellants and explosives is greatly limited.Solving the hygroscopicity of ADN is the key to realize the wide application of ADN.In this paper,we systematically review the research progress of anti-hygroscopic strategies of ADN coating.The surface coating methods are focusing on solvent volatilization,solvent-non-solvent,melt crystallization and atomic layer deposition technology.The characteristics of the different methods are compared and analyzed,and the basis for the classification and selection of the coating materials are introduced in detail.In addition,the feasibility of material for surface coating of ADN is evaluated by several compatibility analysis methods.It is highly expected that the liquid phase method(solvent volatilization method,solvent-non-solvent method)would be the promising method for future ADN coating because of its effective,safety and facile operation.Furthermore,polymer materials,are the preferred coating materials due to their high viscosity,easy adhesion,good anti-hygroscopic effect,and heat resistance,which make ADN weak hygroscopicity,less sensitive,easier to preserve and good compatibility.展开更多
To enhance the catalytic activity of copper ferrite(CuFe_(2)O_(4))nanoparticle and promote its application as combustion catalyst,a low-cost silicon dioxide(SiO_(2))carrier was employed to construct a novel CuFe_(2)O_...To enhance the catalytic activity of copper ferrite(CuFe_(2)O_(4))nanoparticle and promote its application as combustion catalyst,a low-cost silicon dioxide(SiO_(2))carrier was employed to construct a novel CuFe_(2)O_(4)/SiO_(2)binary composites via solvothermal method.The phase structure,morphology and catalytic activity of CuFe_(2)O_(4)/SiO_(2)composites were studied firstly,and thermal decomposition,combustion and safety performance of ammonium perchlorate(AP)and 1,3,5-trinitroperhydro-1,3,5-triazine(RDX)with it affecting were then systematically analyzed.The results show that CuFe_(2)O_(4)/SiO_(2)composite can remarkably either advance the decomposition peak temperature of AP and RDX,or reduce the apparent activation energy at their main decomposition zone.Moreover,the flame propagation rate of RDX was promoted by about 2.73 times with SiO_(2)content of 3 wt%,and safety property of energetic component was also improved greatly,in which depressing the electrostatic discharge sensitivity of pure RDX by about 1.89 times.In addition,the effective range of SiO_(2)carrier content in the binary catalyst is found to be 3 to 5 wt%.Therefore,SiO_(2)opens a new insight on the design of combustion catalyst carrier and will promote the application of CuFe_(2)O_(4)catalyst in solid propellant.展开更多
Smart materials,which exhibit shape memory behavior in response to external stimuli,have shown great potential for use in biomedical applications.In this study,an energetic composite was fabricated using a UV-assisted...Smart materials,which exhibit shape memory behavior in response to external stimuli,have shown great potential for use in biomedical applications.In this study,an energetic composite was fabricated using a UV-assisted DIW 3D printing technique and a shape memory material(SMP)as the binder.This composite has the ability to reduce the impact of external factors and adjust gun propellant combustion behavior.The composition and 3D printing process were delineated,while the internal structure and shape memory performance of the composite material were studied.The energetic SMP composite exhibits an angle of reversal of 18 s at 70°,with a maximum elongation typically reaching up to 280% of the original length and a recovery length of approximately 105%during ten cycles.Additionally,thermal decomposition and combustion behavior were also demonstrated for the energetic SMP composite.展开更多
Energetic structural materials(ESMs)are a new type of structural materials with bearing and damage characteristics.In this work the microstructure,mechanical properties and energy release characteristics of multi-elem...Energetic structural materials(ESMs)are a new type of structural materials with bearing and damage characteristics.In this work the microstructure,mechanical properties and energy release characteristics of multi-element Ti-Zr-Ta alloys with good casting performance were studied.The microstructure of the Ti_(x)ZrTa alloys gradually change from BCC+HCP to single BCC structure with the increase of Ti.While the Ti_(2)Zr_(y)Ta alloys was still uniform and single BCC structure with the increase of Zr.The evolution of microstructure and composition then greatly affect the mechanical properties and energy-release characteristics of Ti-Zr-Ta alloys.The synergistic effect of dual phase structure increases the fracture strain of Ti_(x)ZrTa(x=0.2,0.5)with the Ti content decreases,while the fracture strain of Ti_(x)ZrTa(x=2.0,3.0,4.0)gradually increase with the Ti content increases caused by the annihilation of the obstacles for dislocation movement.And as Zr content increases,the fracture strain of Ti_(2)Zr_(y)Ta alloys decrease,then the oxidation reaction rate and fragmentation degree gradually increase.The higher oxidation rate and the lager exposed oxidation area jointly leads the higher releasing energy efficiency of Ti_(x)ZrTa alloys with low Ti content and Ti_(2)Zr_(y)Ta alloys with high Zr content.展开更多
As a main oxidizer in solid composite propellants,ammonium perchlorate(AP)plays an important role because its thermal decomposition behavior has a direct influence on the characteristic of solid composite propellants....As a main oxidizer in solid composite propellants,ammonium perchlorate(AP)plays an important role because its thermal decomposition behavior has a direct influence on the characteristic of solid composite propellants.To improve the performance of solid composite propellant,it is necessary to take measures to modify the thermal decomposition behavior of AP.In recent years,transition metal oxides and carbon-supported transition metal oxides have drawn considerable attention due to their extraordinary catalytic activity.In this review,we highlight strategies to enhance the thermal decomposition of AP by tuning morphology,varying the types of metal ion,and coupling with carbon analogue.The enhanced catalytic performance can be ascribed to synergistic effect,increased surface area,more exposed active sites,and accelerated electron transportation and so on.The mechanism of AP decomposition mixed with catalyst has also been briefly summarized.Finally,a conclusive outlook and possible research directions are suggested to address challenges such as lacking practical application in actual formulation of solid composite propellant and batch manufacturing.展开更多
Power-conversion-efficiencies(PCEs)of organic solar cells(OSCs)in laboratory,normally processed by spin-coating technology with toxic halogenated solvents,have reached over 19%.However,there is usually a marked PCE dr...Power-conversion-efficiencies(PCEs)of organic solar cells(OSCs)in laboratory,normally processed by spin-coating technology with toxic halogenated solvents,have reached over 19%.However,there is usually a marked PCE drop when the bladecoating and/or green-solvents toward large-scale printing are used instead,which hampers the practical development of OSCs.Here,a new series of N-alkyl-tailored small molecule acceptors named YR-SeNF with a same molecular main backbone are developed by combining selenium-fused central-core and naphthalene-fused endgroup.Thanks to the N-alkyl engineering,NIR-absorbing YR-SeNF series show different crystallinity,packing patterns,and miscibility with polymeric donor.The studies exhibit that the molecular packing,crystallinity,and vertical distribution of active layer morphologies are well optimized by introducing newly designed guest acceptor associated with tailored N-alkyl chains,providing the improved charge transfer dynamics and stability for the PM6:L8-BO:YRSeNF-based OSCs.As a result,a record-high PCE approaching 19%is achieved in the blade-coating OSCs fabricated from a greensolvent o-xylene with high-boiling point.Notably,ternary OSCs offer robust operating stability under maximum-power-point tracking and well-keep>80%of the initial PCEs for even over 400 h.Our alkyl-tailored guest acceptor strategy provides a unique approach to develop green-solvent and blade-coating processed high-efficiency and operating stable OSCs,which paves a way for industrial development.展开更多
Ammonium dinitramide(ADN)is a promising oxidizer with high energy characteristic,which is a relatively new environmentally friendly oxidizer without halogens and carbon elements.However,ADN has high hygroscopicity whe...Ammonium dinitramide(ADN)is a promising oxidizer with high energy characteristic,which is a relatively new environmentally friendly oxidizer without halogens and carbon elements.However,ADN has high hygroscopicity when exposed to high humidity air,restricting its applications on the solid propellants.In this paper,a novel energetic cocrystal composed of ammonium dinitramide and 3,4-diaminofurazan(DAF)was proposed and successfully synthesized by antisolvent crystallization method,and the properties of the cocrystal were systematically investigated by analytical characterization and theoretical simulation calculations.The formation of the cocrystal was confirmed by powder X-ray diffraction,differential scanning calorimetry,scanning electron microscopy,infrared spectroscopy and Raman spectroscopy,indicating that the synthesized product was a cocrystal.Through theoretical studies,the ADN/DAF cocrystal structure was predicted,and the powder X-ray diffraction,morphology,water sorption capacity of ADN/DAF cocrystal were calculated,which was consistent with experimental phenomena.The results showed that newly prepared cocrystal of ADN/DAF had lower hygroscopicity compared to pure ADN,and the water sorption capacity was reduced from 15.35%to 7.90%.This may be due to the formation of N-H…O medium-strength hydrogen bonds between the ammonium ion of ADN and the O atom of DAF in the cocrystal,which prevents the binding of water molecules in the air and ammonium ions and reduces the probability of ADN binding to water molecules,leading to the reduction of cocrystal hygroscopicity.The newly prepared energetic cocrystal can provide theoretical and technical guidance for the study of the anti-hygroscopicity of ADN and advance the practical application of ADN.展开更多
It is important to understand the characteristics of explosive sympathetic detonation for explosive safety.Sympathetic reaction test of GHL(RDX/Al/Binder)explosive charges with shell are conducted.A model of the sympa...It is important to understand the characteristics of explosive sympathetic detonation for explosive safety.Sympathetic reaction test of GHL(RDX/Al/Binder)explosive charges with shell are conducted.A model of the sympathetic reaction test is established.The elements-apart method and nodes random-failure method are used in the model to describe the expansion progress of shell expanding and the randomly forming process of fragments.Random detonation phenomena of acceptor charge are simulated.展开更多
Polyurea is an elastomeric material that can be applied to enhance the protection ability of structures under blast and impact loading.In order to study the compressive mechanical properties of SiC/polyurea nanocompos...Polyurea is an elastomeric material that can be applied to enhance the protection ability of structures under blast and impact loading.In order to study the compressive mechanical properties of SiC/polyurea nanocomposites under quasi-static and dynamic loading,a universal testing machine and split Hopkinson pressure bar(SHPB)apparatus were used respectively.The stress-strain curves were obtained on polyurea and its composites at strain rates of 0.001e8000 s1.The results of the experiment suggested that increase in the strain rates led to the rise of the flow stress,compressive strength,strain rate sensitivity and strain energy.This indicates that all of the presented materials were dependent on strain rate.Moreover,these mechanical characters were enhanced by incorporating a small amount of SiC into polyurea matrix.The relation between yield stress and strain rates were established using the power law functions.Finally,in order to investigate the fracture surfaces and inside information of failed specimens,scanning electron microscopy(SEM)and micro X-ray computed tomography(micro-CT)were used respectively.Multiple voids,crazes,micro-cracks and cracking were observed in fracture surfaces.On the other hand,the cracking propagation was found in the micro-CT slice images.It is essential to understand the deformation and failure mechanisms in all the polyurea materials.展开更多
To optimize the energy output and improve the energy utilization efficiency of an aluminized explosive,an explosion device was developed and used to investigate the detonation pressure and temperature of R1(A16)alumin...To optimize the energy output and improve the energy utilization efficiency of an aluminized explosive,an explosion device was developed and used to investigate the detonation pressure and temperature of R1(A16)aluminum powder and the aluminum powder particle gradation of R2(Al6+Al13),R3(Al6+Al24)and R4(Al6+AI flake)in a confined space.By using gas chromatography,quantitative analysis and calculations were carried out to analyze the gaseous detonation products.Finally,the reaction ratios of the aluminum powder and the explosion reaction equations were calculated.The results show that in a confined space,the quasi-static pressures and equilibrium temperature of the aluminum powder in air are higher than in vacuum.In vacuum,the quasi-static pressures and equilibrium temperatures of the samples in descending order are R1>R3>R4>R2 and R3>R4>R1>R2,respectively.In air,the quasi-static pressures and equilibrium telperatures of the samples in descending order are R1>R2>R4>R3 and R1>R4>R2>R3,respectively.R4(Al6+AI flake)and R3(Al6+A124)have relatively higher temperatures after detonation,which shows that the particle gradation method can enhance the reaction energy output of aluminum during the initial reaction stage of the explosion and increase the reaction ratio by10.6%and 8.0%,respectively.In air,the reaction ratio of AI6 aluminum powder can reach as high as 78.16%,and the reaction ratio is slightly reduced after particle gradation.Finally,the reaction equations of the explosives in vacuum and in air were calculated by quantitative analysis of the explosion products,which provides a powerful basis for the study of RDX-based explosive reactions.展开更多
The linear, directly proportional, equations between the Arrhenius parameters(E_α, and log A) of the thermal decomposition and the crystal lattice free space per molecule, △V, of 22 nitramines are described. It is s...The linear, directly proportional, equations between the Arrhenius parameters(E_α, and log A) of the thermal decomposition and the crystal lattice free space per molecule, △V, of 22 nitramines are described. It is shown that, because of a significant limitation by the molecular structural characteristics of such compounds, they are divided into a number of partial relationships. These partial relationships divide the nitramines into a group of substances relating to dimethyl nitramine and a sub-group related to e-HNIW. These directly proportional equations mean that an increase in the △Vvalues is related to an increase in the thermal stability of the corresponding nitramines. A comparison with similar published dependencies for the impact and friction sensitivities, on the one hand, and with the relationship between the E_a values and the sum of the negative and positive extremes of molecular surface electrostatic potentials, on the other, confirms the well-known fact that intermolecular interaction in the nitramines studied plays a decisive role in the thermal reactivity of such compounds. The crystal lattice free space manifests itself here perhaps only in the solid state thermal decomposition of RDX, HMX and DINGU. This study again confirms a level of disorder in the distribution of the forces in the crystal lattice of the"common" quality of e-HNIW,compared with its "reduced sensitivity(RS)" or pure analogues.展开更多
A differential/integral method to estimate the kinetic parameters(apparent activation energy Eaand pre-exponential factor A) for thermal decomposition reaction of energetic materials based on Kooij formula are applied...A differential/integral method to estimate the kinetic parameters(apparent activation energy Eaand pre-exponential factor A) for thermal decomposition reaction of energetic materials based on Kooij formula are applied to study the nonisothermal decomposition reaction kinetics of hexanitrohexaazaisowurtzitane(HNIW) by analyzing nonisothermal DSC curve data. The apparent activation energy(Ea) obtained by the integral isoconversional non-isothermal method based on Kooij formula is used to check the constancy and validity of apparent activation energy by the differential/integral method based on Kooij formula. The most probable mechanism function of thermal decomposition reaction of HNIW is determined by a logical choice method. The equations for calculating the critical temperatures of thermal explosion(Tb) and adiabatic time-toexplosion(tTIad) based on Kooij formula are used to calculate the values of Tband tTIadto evaluate the thermal safety and heat-resistant ability of HNIW. All the original data needed for analyzing the kinetic parameters are from nonisothermal DSC curves. The results show that the kinetic model function in differential form and the values of Eaand A of decomposition reaction of HNIW are 3(1 a)[ ln(1 a)]2/3, 152.73 kJ mol 1and 1011.97s 1, respectively, and the values of self-accelerating decomposition temperature(TSADT), Tband tTIadare 486.55 K, 493.11 K and52.01 s, respectively.展开更多
The compressive mechanical behavior of composite modified double base(CMDB)propellant was investigated across a wide scope of strain rates ranging from 10^(-3) s^(-1) to 4210 s^(-1) at room temperature,by applying a c...The compressive mechanical behavior of composite modified double base(CMDB)propellant was investigated across a wide scope of strain rates ranging from 10^(-3) s^(-1) to 4210 s^(-1) at room temperature,by applying a conventional universal testing machine and a split Hopkinson tension bar(SHPB),respectively.The derived stress-strain curves at different strain rates show a strong rate dependence,indicated that yield stress,ultimate stress and strain energy density of CMDB propellant all increase with strain rate by following a power law function,while the amplification of increase are different.The deformation and damage modes of CMDB propellant has changed from a typical ductile manner(cracking along the axial direction)to a brittle manner(maximum shear failure)with increasing of strain rate.Scanning electron microscopy(SEM)was employed to explore the microscopic failure characteristics of CMDB propellant.Under quasi-static loading,the nearly parallel micro-cracks propagating along the axial direction and the debonding of RDX particle without particle crushing can be observed.While under dynamic loading,the micro-crack is 45 angle to the axial direction,and multiple cracking modes of RDX particles appeared.Finally,the correlation between strain energy density and failure mechanisms of CMDB propellant was revealed by developing four characteristic failure modes.The findings of this study is very important to evaluate the structural integrity of CMDB propellant.展开更多
Reaxgen program for the pyrolysis mechanism of cycloalkanes was adopted to simulate the heat sink of substituted cyclohexanes. Thermal cracking of cyclohexanes was performed to examine the cracking performance, wherei...Reaxgen program for the pyrolysis mechanism of cycloalkanes was adopted to simulate the heat sink of substituted cyclohexanes. Thermal cracking of cyclohexanes was performed to examine the cracking performance, wherein the substituent effects were detailedly discussed under supercritical condition. It was found that Reaxgen program played a good part in the screening and optimization of cyclohexanes. A good agreement with the experimental data for the mono-substituted and bi-substituted cyclohexanes was demonstrated, however, some deviation for the tri-substituted cyclohexanes were observed. The experiment results indicated that the gaseous product yield increased sharply for monosubstituted cyclohexanes with short substituents containing no more than two carbons. Nevertheless, continuous increase in the alkyl chain depressed the gaseous product yield smoothly. The cyclic substituent dramatically inhibited the pyrolysis of cyclohexanes. All the substituents but cyclohexyl had no obvious effect on the yield of hydrogen and olefins(≤C4). For bi-substituted cyclohexanes, the more close the distance between the two substituents, the higher the gaseous product yield was obtained. However, opposite result on the selectivity to hydrogen and olefins(≤C4) was generally obtained except 1,3-dimethylcyclohexane. The position of tri-substituents acted little significance on the gaseous product yield, as well as the selectivity to hydrogen and olefins(≤C4).展开更多
The research on the damage effectiveness assessment of anti-ship missiles involves system science and weapon science, and has essential strategic research significance. With comprehensive analysis of the specific proc...The research on the damage effectiveness assessment of anti-ship missiles involves system science and weapon science, and has essential strategic research significance. With comprehensive analysis of the specific process of the damage assessment process of anti-missile against ships, a synthetic damage effectiveness assessment process is proposed based on the double hierarchy linguistic term set and the evidence theory. In order to improve the accuracy of the expert ’s assessment information, double hierarchy linguistic terms are used to describe the assessment opinions of experts. In order to avoid the loss of experts ’ original information caused by information fusion rules, the evidence theory is used to fuse the assessment information of various experts on each case. Good stability of the assessment process can be reflected through sensitivity analysis, and the fluctuation of a certain parameter does not have an excessive influence on the assessment results. The assessment process is accurate enough to be reflected through comparative analysis and it has a good advantage in damage effectiveness assessment.展开更多
Nitrogen reduction reaction(NRR)under ambient conditions is always a long-standing challenge in science,due to the extreme difficulty in breaking the strong N≡N triple bond.The key to resolving this issue undoubtedly...Nitrogen reduction reaction(NRR)under ambient conditions is always a long-standing challenge in science,due to the extreme difficulty in breaking the strong N≡N triple bond.The key to resolving this issue undoubtedly lies in searching superior catalysts to efficiently activate and hydrogenate the stable nitrogen molecules.We herein evaluate the feasibility of WP_(2) for N2 activation and reduction,and first demonstrate WP_(2) with an impressive ammonia yield rate of 7.13 lg h^(-1)cm^(-2),representing a promising W-based catalyst for NRR.DFT analysis further reveals that the NRR catalysis on WP_(2) proceeds in a distal reaction pathway,and the exceptional NRR activity is originated from superior surface electron energy level matching between WP_(2) and NRR potential which facilitates the interfacial proton-coupled electron transfer dynamics.The successfully unraveling the intrinsic catalytic mechanism of WP_(2) for NRR could offer a powerful platform to manipulate the NRR activity by tuning the electron energy levels.展开更多
Two polythiophene based polymers,poly[(3-[2-[4-(2-ethyl-hexyloxy)-phenyl]-vinyl]-thiophene)-co-thiophene](PT1)and poly(3-[2-[4-(2-ethyl-hexyloxy)-phenyl]-vinyl]-thiophene)(PT2),are synthesized and investigated by stat...Two polythiophene based polymers,poly[(3-[2-[4-(2-ethyl-hexyloxy)-phenyl]-vinyl]-thiophene)-co-thiophene](PT1)and poly(3-[2-[4-(2-ethyl-hexyloxy)-phenyl]-vinyl]-thiophene)(PT2),are synthesized and investigated by static,picosecond fluorescence spectroscopies and the femtosecond up-conversion technique in solution.Compared with pristine poly(3-hexylthiophene)(P3HT),PT1 and PT2,in which the main chains are decorated with phenyl vinylene present a‘camel back’structure in the absorption spectra.Phenyl vinylene side chains induce a new process of charge transfer,chain twisting motion and defect-induced fluorescence quenching at time scales of 1 ps,10 ps and 150 ps,respectively.展开更多
Selecting the optimal speed for dynamic obstacle avoidance in complex man–machine environments is a challenging problem for mobile robots inspecting hazardous gases.Consideration of personal space is important,especi...Selecting the optimal speed for dynamic obstacle avoidance in complex man–machine environments is a challenging problem for mobile robots inspecting hazardous gases.Consideration of personal space is important,especially in a relatively narrow man–machine dynamic environments such as warehouses and laboratories.In this study,human and robot behaviors in man–machine environments are analyzed,and a man–machine social force model is established to study the robot obstacle avoidance speed.Four typical man–machine behavior patterns are investigated to design the robot behavior strategy.Based on the social force model and man–machine behavior patterns,the fuzzy-PID trajectory tracking control method and the autonomous obstacle avoidance behavior strategy of the mobile robot in inspecting hazardous gases in a relatively narrow man–machine dynamic environment are proposed to determine the optimal robot speed for obstacle avoidance.The simulation analysis results show that compared with the traditional PID control method,the proposed controller has a position error of less than 0.098 m,an angle error of less than 0.088 rad,a smaller steady-state error,and a shorter convergence time.The crossing and encountering pattern experiment results show that the proposed behavior strategy ensures that the robot maintains a safe distance from humans while performing trajectory tracking.This research proposes a combination autonomous behavior strategy for mobile robots inspecting hazardous gases,ensuring that the robot maintains the optimal speed to achieve dynamic obstacle avoidance,reducing human anxiety and increasing comfort in a relatively narrow man–machine environment.展开更多
Based on the virial theory, we proposed VLW equation of state of detonation products (VLW EOS). Its basic theory and applications were described. The distinct features of the VLW EOS were:First, the detonation perform...Based on the virial theory, we proposed VLW equation of state of detonation products (VLW EOS). Its basic theory and applications were described. The distinct features of the VLW EOS were:First, the detonation performance of the new high energy density materials could be predicted more reliably. Second, it had extensive application. The detonation parameters of both the condensed high energy density materials and the gaseous fuel air explosives could be calculated. Moreover, combustion performance of propellants could also be precisely calculated. The calculation results were satisfactory.展开更多
The damage effect assessment of anti-ship missiles combines system science and weapon science,which can provide reference for the assessment of battlefield damage situation.In order to solve the difficulty of heteroge...The damage effect assessment of anti-ship missiles combines system science and weapon science,which can provide reference for the assessment of battlefield damage situation.In order to solve the difficulty of heterogeneous data aggregation and the difficulty in constructing the mapping between factors and damage effect,this paper analyzes the specific damage process of the anti-ship missile to the ship,and proposes a synthetic Evidential Reasoning(ER)–Adaptive Neural Fuzzy Inference System(ANFIS)to assess the damage effect.To solve the problem of fuzziness and uncertainty of criteria in the assessment process,the belief structure model is used to transform qualitative and quantitative information into a unified mathematical structure,and ER algorithm is used to fuse the information of lower-level criteria.In order to solve the problem of fuzziness and uncertainty of the information contained in the first-level variables,and the strong non-linear characteristics of the mapping between first-level variables and damage effect,the ANFIS with selfadaptation and self-learning is constructed.The map between the three first-level variables and damage effect is established,and the interaction process of the various factors in the damage effect assessment are clear.Sensitivity analysis shows that assessment model has good stability.The result analysis and comparative analysis show that the process proposed in this paper can effectively assess the damage effect of anti-ship missiles,and all criteria data are objective and comparable.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.21805139,12102194 and 22005144)the Joint Funds of the National Natural Science Foundation of China(Grant No.U2141202)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.30921011203)the Young Elite Scientists Sponsorship Program by CAST(YESS Program,2021QNRC001)。
文摘Ammonium dinitramide(ADN),which has the advantages of high energy density,no halogen and low characteristic signal,is not only considered as a new high-energy oxidizer that is expected to replace the traditional oxidizer ammonium perchlorate(AP)in solid propellants,but also a good performance explosive in itself.However,due to the strong hygroscopicity of ADN,its application in solid propellants and explosives is greatly limited.Solving the hygroscopicity of ADN is the key to realize the wide application of ADN.In this paper,we systematically review the research progress of anti-hygroscopic strategies of ADN coating.The surface coating methods are focusing on solvent volatilization,solvent-non-solvent,melt crystallization and atomic layer deposition technology.The characteristics of the different methods are compared and analyzed,and the basis for the classification and selection of the coating materials are introduced in detail.In addition,the feasibility of material for surface coating of ADN is evaluated by several compatibility analysis methods.It is highly expected that the liquid phase method(solvent volatilization method,solvent-non-solvent method)would be the promising method for future ADN coating because of its effective,safety and facile operation.Furthermore,polymer materials,are the preferred coating materials due to their high viscosity,easy adhesion,good anti-hygroscopic effect,and heat resistance,which make ADN weak hygroscopicity,less sensitive,easier to preserve and good compatibility.
基金the National Nature Science Foundation of China(Grant Nos.21673178,22105160)the Natural Science Foundation of Shaanxi Province(Grant No.2023-JC-ZD-07)+1 种基金the Foundation of Key Laboratory of Defense Science and technology(Grant No.6142603032213)the Key Science and Technology Innovation Team of Shaanxi Province(Grant No.2022TD-33).
文摘To enhance the catalytic activity of copper ferrite(CuFe_(2)O_(4))nanoparticle and promote its application as combustion catalyst,a low-cost silicon dioxide(SiO_(2))carrier was employed to construct a novel CuFe_(2)O_(4)/SiO_(2)binary composites via solvothermal method.The phase structure,morphology and catalytic activity of CuFe_(2)O_(4)/SiO_(2)composites were studied firstly,and thermal decomposition,combustion and safety performance of ammonium perchlorate(AP)and 1,3,5-trinitroperhydro-1,3,5-triazine(RDX)with it affecting were then systematically analyzed.The results show that CuFe_(2)O_(4)/SiO_(2)composite can remarkably either advance the decomposition peak temperature of AP and RDX,or reduce the apparent activation energy at their main decomposition zone.Moreover,the flame propagation rate of RDX was promoted by about 2.73 times with SiO_(2)content of 3 wt%,and safety property of energetic component was also improved greatly,in which depressing the electrostatic discharge sensitivity of pure RDX by about 1.89 times.In addition,the effective range of SiO_(2)carrier content in the binary catalyst is found to be 3 to 5 wt%.Therefore,SiO_(2)opens a new insight on the design of combustion catalyst carrier and will promote the application of CuFe_(2)O_(4)catalyst in solid propellant.
文摘Smart materials,which exhibit shape memory behavior in response to external stimuli,have shown great potential for use in biomedical applications.In this study,an energetic composite was fabricated using a UV-assisted DIW 3D printing technique and a shape memory material(SMP)as the binder.This composite has the ability to reduce the impact of external factors and adjust gun propellant combustion behavior.The composition and 3D printing process were delineated,while the internal structure and shape memory performance of the composite material were studied.The energetic SMP composite exhibits an angle of reversal of 18 s at 70°,with a maximum elongation typically reaching up to 280% of the original length and a recovery length of approximately 105%during ten cycles.Additionally,thermal decomposition and combustion behavior were also demonstrated for the energetic SMP composite.
基金supported by the National Natural Science Foundation of China(Grant Nos.52171166,11972372 and U20A20231)supported by Sinoma Institute of Materials Research(Guang Zhou)Co.,Ltd。
文摘Energetic structural materials(ESMs)are a new type of structural materials with bearing and damage characteristics.In this work the microstructure,mechanical properties and energy release characteristics of multi-element Ti-Zr-Ta alloys with good casting performance were studied.The microstructure of the Ti_(x)ZrTa alloys gradually change from BCC+HCP to single BCC structure with the increase of Ti.While the Ti_(2)Zr_(y)Ta alloys was still uniform and single BCC structure with the increase of Zr.The evolution of microstructure and composition then greatly affect the mechanical properties and energy-release characteristics of Ti-Zr-Ta alloys.The synergistic effect of dual phase structure increases the fracture strain of Ti_(x)ZrTa(x=0.2,0.5)with the Ti content decreases,while the fracture strain of Ti_(x)ZrTa(x=2.0,3.0,4.0)gradually increase with the Ti content increases caused by the annihilation of the obstacles for dislocation movement.And as Zr content increases,the fracture strain of Ti_(2)Zr_(y)Ta alloys decrease,then the oxidation reaction rate and fragmentation degree gradually increase.The higher oxidation rate and the lager exposed oxidation area jointly leads the higher releasing energy efficiency of Ti_(x)ZrTa alloys with low Ti content and Ti_(2)Zr_(y)Ta alloys with high Zr content.
基金This work was financially supported by the Science and Technology project of Jiangsu province(BN2015021,XZ-SZ201819).
文摘As a main oxidizer in solid composite propellants,ammonium perchlorate(AP)plays an important role because its thermal decomposition behavior has a direct influence on the characteristic of solid composite propellants.To improve the performance of solid composite propellant,it is necessary to take measures to modify the thermal decomposition behavior of AP.In recent years,transition metal oxides and carbon-supported transition metal oxides have drawn considerable attention due to their extraordinary catalytic activity.In this review,we highlight strategies to enhance the thermal decomposition of AP by tuning morphology,varying the types of metal ion,and coupling with carbon analogue.The enhanced catalytic performance can be ascribed to synergistic effect,increased surface area,more exposed active sites,and accelerated electron transportation and so on.The mechanism of AP decomposition mixed with catalyst has also been briefly summarized.Finally,a conclusive outlook and possible research directions are suggested to address challenges such as lacking practical application in actual formulation of solid composite propellant and batch manufacturing.
基金the support from the NSFC (22209131, 22005121, 21875182, and 52173023)National Key Research and Development Program of China (2022YFE0132400)+4 种基金Key Scientific and Technological Innovation Team Project of Shaanxi Province (2020TD-002)111 project 2.0 (BP0618008)Open Fund of Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications (Changzhou University, GDRGCS2022002)Open Fund of Key Laboratory of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education (Jiangxi Normal University, KFSEMC-202201)acquired at beamlines 7.3.3 and 11.0.1.2 at the Advanced Light Source, which is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC0205CH11231
文摘Power-conversion-efficiencies(PCEs)of organic solar cells(OSCs)in laboratory,normally processed by spin-coating technology with toxic halogenated solvents,have reached over 19%.However,there is usually a marked PCE drop when the bladecoating and/or green-solvents toward large-scale printing are used instead,which hampers the practical development of OSCs.Here,a new series of N-alkyl-tailored small molecule acceptors named YR-SeNF with a same molecular main backbone are developed by combining selenium-fused central-core and naphthalene-fused endgroup.Thanks to the N-alkyl engineering,NIR-absorbing YR-SeNF series show different crystallinity,packing patterns,and miscibility with polymeric donor.The studies exhibit that the molecular packing,crystallinity,and vertical distribution of active layer morphologies are well optimized by introducing newly designed guest acceptor associated with tailored N-alkyl chains,providing the improved charge transfer dynamics and stability for the PM6:L8-BO:YRSeNF-based OSCs.As a result,a record-high PCE approaching 19%is achieved in the blade-coating OSCs fabricated from a greensolvent o-xylene with high-boiling point.Notably,ternary OSCs offer robust operating stability under maximum-power-point tracking and well-keep>80%of the initial PCEs for even over 400 h.Our alkyl-tailored guest acceptor strategy provides a unique approach to develop green-solvent and blade-coating processed high-efficiency and operating stable OSCs,which paves a way for industrial development.
基金supported by the National Natural Science Foundation of China(22125802)Beijing Natural Science Foundation(2222017)National key research and development program(2021YFC2101202)。
文摘Ammonium dinitramide(ADN)is a promising oxidizer with high energy characteristic,which is a relatively new environmentally friendly oxidizer without halogens and carbon elements.However,ADN has high hygroscopicity when exposed to high humidity air,restricting its applications on the solid propellants.In this paper,a novel energetic cocrystal composed of ammonium dinitramide and 3,4-diaminofurazan(DAF)was proposed and successfully synthesized by antisolvent crystallization method,and the properties of the cocrystal were systematically investigated by analytical characterization and theoretical simulation calculations.The formation of the cocrystal was confirmed by powder X-ray diffraction,differential scanning calorimetry,scanning electron microscopy,infrared spectroscopy and Raman spectroscopy,indicating that the synthesized product was a cocrystal.Through theoretical studies,the ADN/DAF cocrystal structure was predicted,and the powder X-ray diffraction,morphology,water sorption capacity of ADN/DAF cocrystal were calculated,which was consistent with experimental phenomena.The results showed that newly prepared cocrystal of ADN/DAF had lower hygroscopicity compared to pure ADN,and the water sorption capacity was reduced from 15.35%to 7.90%.This may be due to the formation of N-H…O medium-strength hydrogen bonds between the ammonium ion of ADN and the O atom of DAF in the cocrystal,which prevents the binding of water molecules in the air and ammonium ions and reduces the probability of ADN binding to water molecules,leading to the reduction of cocrystal hygroscopicity.The newly prepared energetic cocrystal can provide theoretical and technical guidance for the study of the anti-hygroscopicity of ADN and advance the practical application of ADN.
文摘It is important to understand the characteristics of explosive sympathetic detonation for explosive safety.Sympathetic reaction test of GHL(RDX/Al/Binder)explosive charges with shell are conducted.A model of the sympathetic reaction test is established.The elements-apart method and nodes random-failure method are used in the model to describe the expansion progress of shell expanding and the randomly forming process of fragments.Random detonation phenomena of acceptor charge are simulated.
基金The authors would like to thank the State Administration of Science,Technology and Industry for National Defense of China(Grant No.WDZCKYXM20190503)Xi’an Modern Chemistry Institute for the financial support.Beijing Institute of Technology and Northwestern Polytechnical University are thanked for providing experimental equipments for this work.
文摘Polyurea is an elastomeric material that can be applied to enhance the protection ability of structures under blast and impact loading.In order to study the compressive mechanical properties of SiC/polyurea nanocomposites under quasi-static and dynamic loading,a universal testing machine and split Hopkinson pressure bar(SHPB)apparatus were used respectively.The stress-strain curves were obtained on polyurea and its composites at strain rates of 0.001e8000 s1.The results of the experiment suggested that increase in the strain rates led to the rise of the flow stress,compressive strength,strain rate sensitivity and strain energy.This indicates that all of the presented materials were dependent on strain rate.Moreover,these mechanical characters were enhanced by incorporating a small amount of SiC into polyurea matrix.The relation between yield stress and strain rates were established using the power law functions.Finally,in order to investigate the fracture surfaces and inside information of failed specimens,scanning electron microscopy(SEM)and micro X-ray computed tomography(micro-CT)were used respectively.Multiple voids,crazes,micro-cracks and cracking were observed in fracture surfaces.On the other hand,the cracking propagation was found in the micro-CT slice images.It is essential to understand the deformation and failure mechanisms in all the polyurea materials.
基金supported by National Natural Science Foundation of China (Grant no.11502194)
文摘To optimize the energy output and improve the energy utilization efficiency of an aluminized explosive,an explosion device was developed and used to investigate the detonation pressure and temperature of R1(A16)aluminum powder and the aluminum powder particle gradation of R2(Al6+Al13),R3(Al6+Al24)and R4(Al6+AI flake)in a confined space.By using gas chromatography,quantitative analysis and calculations were carried out to analyze the gaseous detonation products.Finally,the reaction ratios of the aluminum powder and the explosion reaction equations were calculated.The results show that in a confined space,the quasi-static pressures and equilibrium temperature of the aluminum powder in air are higher than in vacuum.In vacuum,the quasi-static pressures and equilibrium temperatures of the samples in descending order are R1>R3>R4>R2 and R3>R4>R1>R2,respectively.In air,the quasi-static pressures and equilibrium telperatures of the samples in descending order are R1>R2>R4>R3 and R1>R4>R2>R3,respectively.R4(Al6+AI flake)and R3(Al6+A124)have relatively higher temperatures after detonation,which shows that the particle gradation method can enhance the reaction energy output of aluminum during the initial reaction stage of the explosion and increase the reaction ratio by10.6%and 8.0%,respectively.In air,the reaction ratio of AI6 aluminum powder can reach as high as 78.16%,and the reaction ratio is slightly reduced after particle gradation.Finally,the reaction equations of the explosives in vacuum and in air were calculated by quantitative analysis of the explosion products,which provides a powerful basis for the study of RDX-based explosive reactions.
基金support from the Students Grant Projects No.SGSFCHT_2016002 of the Faculty of Chemical Technology at the University of Pardubicefinancial support came from the Chinese State Administration of Foreign Experts Affairs
文摘The linear, directly proportional, equations between the Arrhenius parameters(E_α, and log A) of the thermal decomposition and the crystal lattice free space per molecule, △V, of 22 nitramines are described. It is shown that, because of a significant limitation by the molecular structural characteristics of such compounds, they are divided into a number of partial relationships. These partial relationships divide the nitramines into a group of substances relating to dimethyl nitramine and a sub-group related to e-HNIW. These directly proportional equations mean that an increase in the △Vvalues is related to an increase in the thermal stability of the corresponding nitramines. A comparison with similar published dependencies for the impact and friction sensitivities, on the one hand, and with the relationship between the E_a values and the sum of the negative and positive extremes of molecular surface electrostatic potentials, on the other, confirms the well-known fact that intermolecular interaction in the nitramines studied plays a decisive role in the thermal reactivity of such compounds. The crystal lattice free space manifests itself here perhaps only in the solid state thermal decomposition of RDX, HMX and DINGU. This study again confirms a level of disorder in the distribution of the forces in the crystal lattice of the"common" quality of e-HNIW,compared with its "reduced sensitivity(RS)" or pure analogues.
文摘A differential/integral method to estimate the kinetic parameters(apparent activation energy Eaand pre-exponential factor A) for thermal decomposition reaction of energetic materials based on Kooij formula are applied to study the nonisothermal decomposition reaction kinetics of hexanitrohexaazaisowurtzitane(HNIW) by analyzing nonisothermal DSC curve data. The apparent activation energy(Ea) obtained by the integral isoconversional non-isothermal method based on Kooij formula is used to check the constancy and validity of apparent activation energy by the differential/integral method based on Kooij formula. The most probable mechanism function of thermal decomposition reaction of HNIW is determined by a logical choice method. The equations for calculating the critical temperatures of thermal explosion(Tb) and adiabatic time-toexplosion(tTIad) based on Kooij formula are used to calculate the values of Tband tTIadto evaluate the thermal safety and heat-resistant ability of HNIW. All the original data needed for analyzing the kinetic parameters are from nonisothermal DSC curves. The results show that the kinetic model function in differential form and the values of Eaand A of decomposition reaction of HNIW are 3(1 a)[ ln(1 a)]2/3, 152.73 kJ mol 1and 1011.97s 1, respectively, and the values of self-accelerating decomposition temperature(TSADT), Tband tTIadare 486.55 K, 493.11 K and52.01 s, respectively.
文摘The compressive mechanical behavior of composite modified double base(CMDB)propellant was investigated across a wide scope of strain rates ranging from 10^(-3) s^(-1) to 4210 s^(-1) at room temperature,by applying a conventional universal testing machine and a split Hopkinson tension bar(SHPB),respectively.The derived stress-strain curves at different strain rates show a strong rate dependence,indicated that yield stress,ultimate stress and strain energy density of CMDB propellant all increase with strain rate by following a power law function,while the amplification of increase are different.The deformation and damage modes of CMDB propellant has changed from a typical ductile manner(cracking along the axial direction)to a brittle manner(maximum shear failure)with increasing of strain rate.Scanning electron microscopy(SEM)was employed to explore the microscopic failure characteristics of CMDB propellant.Under quasi-static loading,the nearly parallel micro-cracks propagating along the axial direction and the debonding of RDX particle without particle crushing can be observed.While under dynamic loading,the micro-crack is 45 angle to the axial direction,and multiple cracking modes of RDX particles appeared.Finally,the correlation between strain energy density and failure mechanisms of CMDB propellant was revealed by developing four characteristic failure modes.The findings of this study is very important to evaluate the structural integrity of CMDB propellant.
基金supported by the Special Program for Key Basic Research in China(Grant No.0040202204)
文摘Reaxgen program for the pyrolysis mechanism of cycloalkanes was adopted to simulate the heat sink of substituted cyclohexanes. Thermal cracking of cyclohexanes was performed to examine the cracking performance, wherein the substituent effects were detailedly discussed under supercritical condition. It was found that Reaxgen program played a good part in the screening and optimization of cyclohexanes. A good agreement with the experimental data for the mono-substituted and bi-substituted cyclohexanes was demonstrated, however, some deviation for the tri-substituted cyclohexanes were observed. The experiment results indicated that the gaseous product yield increased sharply for monosubstituted cyclohexanes with short substituents containing no more than two carbons. Nevertheless, continuous increase in the alkyl chain depressed the gaseous product yield smoothly. The cyclic substituent dramatically inhibited the pyrolysis of cyclohexanes. All the substituents but cyclohexyl had no obvious effect on the yield of hydrogen and olefins(≤C4). For bi-substituted cyclohexanes, the more close the distance between the two substituents, the higher the gaseous product yield was obtained. However, opposite result on the selectivity to hydrogen and olefins(≤C4) was generally obtained except 1,3-dimethylcyclohexane. The position of tri-substituents acted little significance on the gaseous product yield, as well as the selectivity to hydrogen and olefins(≤C4).
文摘The research on the damage effectiveness assessment of anti-ship missiles involves system science and weapon science, and has essential strategic research significance. With comprehensive analysis of the specific process of the damage assessment process of anti-missile against ships, a synthetic damage effectiveness assessment process is proposed based on the double hierarchy linguistic term set and the evidence theory. In order to improve the accuracy of the expert ’s assessment information, double hierarchy linguistic terms are used to describe the assessment opinions of experts. In order to avoid the loss of experts ’ original information caused by information fusion rules, the evidence theory is used to fuse the assessment information of various experts on each case. Good stability of the assessment process can be reflected through sensitivity analysis, and the fluctuation of a certain parameter does not have an excessive influence on the assessment results. The assessment process is accurate enough to be reflected through comparative analysis and it has a good advantage in damage effectiveness assessment.
基金financial support from the National Natural Science Foundation of China(Nos.21771169,11804325,11722543,11875258,11505187)the National Key Research and Development Program of China(2017YFA0206703)+3 种基金Anhui Provincial Natural Science Foundation(BJ2060190077)USTC start-up fundingRecruitment Program of Global Expertthe Fundamental Research Funds for the Central Universities(WK2060190074,WK2060190081,WK2310000066)。
文摘Nitrogen reduction reaction(NRR)under ambient conditions is always a long-standing challenge in science,due to the extreme difficulty in breaking the strong N≡N triple bond.The key to resolving this issue undoubtedly lies in searching superior catalysts to efficiently activate and hydrogenate the stable nitrogen molecules.We herein evaluate the feasibility of WP_(2) for N2 activation and reduction,and first demonstrate WP_(2) with an impressive ammonia yield rate of 7.13 lg h^(-1)cm^(-2),representing a promising W-based catalyst for NRR.DFT analysis further reveals that the NRR catalysis on WP_(2) proceeds in a distal reaction pathway,and the exceptional NRR activity is originated from superior surface electron energy level matching between WP_(2) and NRR potential which facilitates the interfacial proton-coupled electron transfer dynamics.The successfully unraveling the intrinsic catalytic mechanism of WP_(2) for NRR could offer a powerful platform to manipulate the NRR activity by tuning the electron energy levels.
基金by the National Natural Science Foundation of China under Grant Nos 10504001,60878019,10821062,10934001,60677002,10828407the National Basic Research Program of China under Grant Nos 2009CB930504,2007CB307001,2006CB921601,2006CB806007.
文摘Two polythiophene based polymers,poly[(3-[2-[4-(2-ethyl-hexyloxy)-phenyl]-vinyl]-thiophene)-co-thiophene](PT1)and poly(3-[2-[4-(2-ethyl-hexyloxy)-phenyl]-vinyl]-thiophene)(PT2),are synthesized and investigated by static,picosecond fluorescence spectroscopies and the femtosecond up-conversion technique in solution.Compared with pristine poly(3-hexylthiophene)(P3HT),PT1 and PT2,in which the main chains are decorated with phenyl vinylene present a‘camel back’structure in the absorption spectra.Phenyl vinylene side chains induce a new process of charge transfer,chain twisting motion and defect-induced fluorescence quenching at time scales of 1 ps,10 ps and 150 ps,respectively.
基金Research and Development Program of Xi’an Modern Chemistry Research Institute of Chnia(Grant No.204J201916234/6)Key Project of Liuzhou Science and Technology Bureau of China(Grant No.2020PAAA0601).
文摘Selecting the optimal speed for dynamic obstacle avoidance in complex man–machine environments is a challenging problem for mobile robots inspecting hazardous gases.Consideration of personal space is important,especially in a relatively narrow man–machine dynamic environments such as warehouses and laboratories.In this study,human and robot behaviors in man–machine environments are analyzed,and a man–machine social force model is established to study the robot obstacle avoidance speed.Four typical man–machine behavior patterns are investigated to design the robot behavior strategy.Based on the social force model and man–machine behavior patterns,the fuzzy-PID trajectory tracking control method and the autonomous obstacle avoidance behavior strategy of the mobile robot in inspecting hazardous gases in a relatively narrow man–machine dynamic environment are proposed to determine the optimal robot speed for obstacle avoidance.The simulation analysis results show that compared with the traditional PID control method,the proposed controller has a position error of less than 0.098 m,an angle error of less than 0.088 rad,a smaller steady-state error,and a shorter convergence time.The crossing and encountering pattern experiment results show that the proposed behavior strategy ensures that the robot maintains a safe distance from humans while performing trajectory tracking.This research proposes a combination autonomous behavior strategy for mobile robots inspecting hazardous gases,ensuring that the robot maintains the optimal speed to achieve dynamic obstacle avoidance,reducing human anxiety and increasing comfort in a relatively narrow man–machine environment.
基金Supported by the National Natural Science Foundation of China (Grant No. 1860382)the Science Foundation of China Academy of Engineering Physics (Grant Nos. 920513, 9401009 & 960577)
文摘Based on the virial theory, we proposed VLW equation of state of detonation products (VLW EOS). Its basic theory and applications were described. The distinct features of the VLW EOS were:First, the detonation performance of the new high energy density materials could be predicted more reliably. Second, it had extensive application. The detonation parameters of both the condensed high energy density materials and the gaseous fuel air explosives could be calculated. Moreover, combustion performance of propellants could also be precisely calculated. The calculation results were satisfactory.
文摘The damage effect assessment of anti-ship missiles combines system science and weapon science,which can provide reference for the assessment of battlefield damage situation.In order to solve the difficulty of heterogeneous data aggregation and the difficulty in constructing the mapping between factors and damage effect,this paper analyzes the specific damage process of the anti-ship missile to the ship,and proposes a synthetic Evidential Reasoning(ER)–Adaptive Neural Fuzzy Inference System(ANFIS)to assess the damage effect.To solve the problem of fuzziness and uncertainty of criteria in the assessment process,the belief structure model is used to transform qualitative and quantitative information into a unified mathematical structure,and ER algorithm is used to fuse the information of lower-level criteria.In order to solve the problem of fuzziness and uncertainty of the information contained in the first-level variables,and the strong non-linear characteristics of the mapping between first-level variables and damage effect,the ANFIS with selfadaptation and self-learning is constructed.The map between the three first-level variables and damage effect is established,and the interaction process of the various factors in the damage effect assessment are clear.Sensitivity analysis shows that assessment model has good stability.The result analysis and comparative analysis show that the process proposed in this paper can effectively assess the damage effect of anti-ship missiles,and all criteria data are objective and comparable.
