检索结果-南通市图书馆

Combustion behavior and mechanism of molecular perovskite energetic material DAP-4-based composites with metal fuel Al

在线全文

学校读者我要写书评

暂无评论

Defence Technology(防务技术) 2023年第9期27卷 53-63页

作者： peng Deng Xue-yong Guo Hua Fang Rui Liu peng-wan chen State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081PR China

Combined with the oxidizer anions and fuel cations,molecular perovskite energetic materials show a good potential.In this work,the combustion behavior and mechanism of metal fuel aluminium(Al)with molecular perovskite energetic material(H_(2)dabco)[NH4(ClO_(4))_(3)](DAP-4)as a high-energy oxidant was investigated.The DAP-4 based composites with metal fuel Al were designed and fabricated by the different mass ratios.Results showed that DAP-4 exhibits a good oxygen-supplied capacity for enhancing the combustion performance of Al.The maximum combustion heat of DAP-4/Al-3 at the Al/O mass ratio of 38:62 is up to 10,412 J/g in the inert gas,which is higher than those of other ratios and the mixtures of other energetic materials and Al.The evolution of pressure output,pressurization rate,and flame temperature was monitored for DAP-4/Al with different mass ratios.Composites DAP-4/Al/F were characterized by burning rates.The combustion reaction mechanism of metal fuel Al with DAP-4 as a high-energy oxidant was provided.DAP-4 was ignited firstly and released acid and oxidizing gases,which corroded Al_(2)O_(3)shells on Al particle surfaces and accelerated the combustion reaction with Al to release a lot of energy.This work offered a new idea that molecular perovskite energetic materials have great potential in the high-energy Al-based solid rocket propellants.

关键词： DAP-4 Metal fuel al Oxidant Combustion behavior Reaction mechanism

Time-sequenced damage behavior of reactive projectile impacting double-layer plates

在线全文

学校读者我要写书评

暂无评论

Defence Technology(防务技术) 2023年第9期27卷 263-272页

作者： Ying Yuan Yi-qiang Cai Huan-guo Guo peng-wan chen Rui Liu Hai-fu wang Beijing Institute of Technology Beijing100081China

The time-sequenced damage behavior of the reactive projectile impacting double-layer plates is discussed.The analytical model considering the combined effect of kinetic and chemical energy is developed to reveal the damage mechanism.The influences of impact velocity and reactive projectile chemical characteristics on the damage effect are decoupled analyzed based on this model.These analyses indicate that the high energy releasing efficiency and fast reaction propagation velocity of the reactive projectile are conducive to enhancing the damage effect.The experiments with various reactive projectiles impact velocity increasing from 702 to 1385 m/s were conducted to verify this model.The experimental results presented that,the damage hole radius of the rear-plate increases with the increase of impact velocity.At the impact velocity of 1350 m/s,the radius of damage hole formed by PTFE/Al/Bi_(2)O_(3),PTFE/Al/MoO_(3),PTFE/Al/Fe_(2)O_(3)projectile on the rear-plate become smaller in sequence.These results are consistent with the analytical model prediction,demonstrating that this model can predict the damage effect quantitatively.This work is of constructive significance to the application of reactive projectiles.

关键词： Reactive projectile Damage behaviors Impact Double-layer plates

Experimental and numerical investigations of interface properties of Ti6Al4V/CP-Ti/Copper composite plate prepared by explosive welding

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2021年第5期17卷 1592-1601页

作者： Yasir Mahmood peng-wan chen I.A.Bataev Xin Gao State Key Lab of Explosion Science and Technology Beijing Institute of Technology100081PR China Novosibirsk State Technical University K.Marks 20630073NovosibirskRussia

Explosive welding technique is widely used in many industries.This technique is useful to weld different kinds of metal alloys that are not easily welded by any other welding methods.Interlayer plays an important role to improve the welding quality and control energy loss during the collision process.In this paper,the Ti6Al4V plate was welded with a copper plate in the presence of a commercially pure titanium interlayer.Microstructure details of welded composite plate were observed through optical and scanning electron microscope.Interlayer-base plate interface morphology showed a wavy structure with solid melted regions inside the vortices.Moreover,the energy dispersive spectroscopy analysis in the interlayer-base interface reveals that there are some identified regions of different kinds of chemical equilibrium phases of CueTi,i.e.CuTi,Cu_(2)Ti,CuTi_(2),Cu_(4)Ti,etc.To study the mechanical properties of composite plates,mechanical tests were conducted,including the tensile test,bending test,shear test and Vickers hardness test.Numerical simulation of explosive welding process was performed with coupled Smooth Particle Hydrodynamic method,Euler and Arbitrary Lagrangian-Eulerian method.The multi-physics process of explosive welding,including detonation,jetting and interface morphology,was observed with simulation.Moreover,simulated plastic strain,temperature and pressure profiles were analysed to understand the welding conditions.Simulated results show that the interlayer base plate interface was created due to the high plastic deformation and localized melting of the parent plates.At the collision point,both alloys behave like fluids,resulting in the formation of a wavy morphology with vortices,which is in good agreement with the experimental results.

关键词： Explosive welding Ti6Al4V/CP-Ti/Cu Smooth particle hydrodynamic(SPH) Microstructure Mechanical properties

High strain rate deformation of explosion-welded Ti6Al4V/pure titanium

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2020年第3期16卷 678-688页

作者： Yan-song Guo peng-wan chen Ali Arab Qiang Zhou Yasir Mahmood State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081PR China

Multilayer materials are widely used in military,automobile and aerospace industries.In this paper,the response of an explosion-welded Ti6Al4V/pure titanium with a flat interface to dynamic loading is investigated.An SHPB apparatus is used.Then,the dynamic behaviour of a bimetal sample is explored with a DIC system coupled to the SHPB.Result indicates that in the bimetal sample pure titanium is deformed and failed before Ti6Al4V.The stress curve of the sample shows two different peaks in a striker velocity higher than the 18.3 m/s.When the incident wave encounters the interface of the Ti6Al4V/pure titanium sample,only a small fraction of the wave is reflected owing to similar impedance.Using the direct interpretation stress-strain curve is unreasonable in this case because of unhomogenised plastic deformation.The micro structure of the sample is investigated after loading.An adiabatic shear band is formed in the pure titanium side before failure,and the interface of the sample remains intact under different loading conditions.The FEM simulation result for the sample is in good agreement with experimental observations.

关键词： Explosion welded Dynamic behaviour SHPB Titanium alloy

Mechanical behavior and failure mechanism of polyurea nanocomposites under quasi-static and dynamic compressive loading

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2021年第2期17卷 495-504页

作者： Qiang Liu peng-wan chen Yan-song Guo Jian-jun Su Lu Han Ali Arab Jian-fei Yuan State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China Xi’an Modern Chemistry Research Institute Xi’an 710065China

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.

关键词： Polyurea nanocomposites Mechanical properties Strain rate Micro-CT Failure

Improving landscape connectivity through habitat restoration:application for Asian elephant conservation in Xishuangbanna Prefecture,China

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2024年第2期19卷 319-335页

作者： Bin wan Wenwen LI peng LIU Nian YANG Shang chen Xianming GUO Bin wanG Li ZHANG Key Laboratory for Biodiversity Science and Ecological Engineering Ministry of EducationCollege of Life SciencesBeijing Normal UniversityBeijingChina Research Center for Coastal Zone Science and Marine Development Strategy First Institute of OceanographyMinistry of Natural ResourcesQingdaoChina School of Biological Sciences The University of Hong KongPokfulamHong KongChina Research Institute of Xishuangbanna National Nature Reserve JinghongChina Xishuangbanna Asian Elephant Conservation and Management Center JinghongChina

Habitat restoration is an effective method for improving landscape connectivity,which can reduce habitat fragmentation.Maintaining landscape connectivity could promote connections between habitat,which is extremely essential to preserve gene flow and population viability.This study proposes a methodological framework to analyze landscape connectivity for Asian elephant habitat conservation,aiming to provide practical options for reducing habitat fragmentation and improving habitat connectivity.Our approach involved combining a species distribution model using MaxEnt and landscape functional connectivity models using graph theory to assess the impact on connectivity improvement via farmland/plantation restoration as habitat.The results showed that:(1)there were 119 suitable habitat patches of Asian elephant covering a total area of 1952.41 km^(2).(2)The connectivity between habitats improved significantly after vegetation restoration and the gain first decreased and then increased with the increase of dispersal distance.(3)The first few new habitat patches that were identified played an important role in improving connectivity,and the variation rate of connectivity gradually leveled off as the number of new habitats increased.(4)Prioritization of the 25 best new habitat patches increased connectivity from 0.54%to 5.59%as the dispersal distance increased and mainly was located between two Asian elephant distribution regions and two components.Establishment of new habitat patches was effective for improving or restoring connectivity.Our findings can be used as guidance for improving the studied fragmented Asian elephant habitats,and they can also be used as a reference for the habitat restoration of other endangered species heavily affected by habitat fragmentation.

关键词： Asian elephant connectivity habitat restoration habitat suitability landscape graphs

Evaluation of water management on arsenic methylation and volatilization in arsenic-contaminated soils strengthened by bioaugmentation and biostimulation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第3期137卷 515-526页

作者： peng chen Yi Liu Guo-Xin Sun State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhan 430074China University of Chinese Academy of Sciences Beijing 100049China

Arsenic(As) fate in paddy fields has been one of the most significant current issues due to the strong As accumulation potential of rice plants under fooded conditions. However,no attempt was done to explore As methylation and volatilization under non-fooded conditions. Herein, we investigated the effects of water management on As methylation and volatilization in three arsenic-contaminated soils enhanced by biostimulation with strawderived organic matter and bioaugmentation with genetic engineered Pseudomonas putida KT2440(GE P. putida). Under fooded conditions, the application of biochar(BC), rice straw(RS)and their combination(BC+RS) increased total As in porewater. However, these effects were greatly attenuated under non-fooded conditions. Compared with RS amendment alone, the combination of GE P. putida and RS further promoted the As methylation and volatilization,and the promotion percentage under non-fooded conditions were significantly higher than that under fooded conditions. The combined GE P. putida and RS showed the highest efficiency in As methylation(88 μg/L) and volatilization(415.4 μg/(kg·year)) in the non-fooded soil with moderate As contamination. Finally, stepwise multiple linear regression analysis presented that methylated As, DOC and p H in porewater were the most important factors contributing to As volatilization. Overall, our findings suggest that combination of bioaugmentation with GE P. putida and biostimulation with RS/BC+RS is a potential strategy for bioremediation of arsenic-contaminated soils by enhancing As methylation and volatilization under non-fooded conditions.

关键词： Arsenic methylation Arsenic volatilization Water management Straw incorporation Bioaugmentation

Magnetic Fields Reduce Apoptosis by Suppressing Phase Separation of Tau-441

在线全文

学校读者我要写书评

暂无评论

Research 2024年第1期2023卷 181-197页

作者： Wen-Juan Lin Wen-Pu Shi wan-Yi Ge Liang-Liang chen Wei-Hong Guo peng Shang Da-Chuan Yin Key Laboratory for Space Bioscience and Biotechnology School of Life SciencesNorthwestern Polytechnical University127 Youyixi RoadXi'an 710072ShaanxiPR China

The biological effects of magnetic fields(MFs)have been a controversial issue.Fortunately,in recent years,there has been increasing evidence that MFs do affect biological systems.However,the physical mechanism remains unclear.Here,we show that MFs(16 T)reduce apoptosis in cell lines by inhibiting liquid–liquid phase separation(LLPS)of Tau-441,suggesting that the MF effect on LLPS may be one of the mechanisms for understanding the“mysterious”magnetobiological effects.The LLPS of Tau-441 occurred in the cytoplasm after induction with arsenite.The phase-separated droplets of Tau-441 recruited hexokinase(HK),resulting in a decrease in the amount of free HK in the cytoplasm.In cells,HK and Bax compete to bind to the voltage-dependent anion channel(VDAC I)on the mitochondrial membrane.A decrease in the number of free HK molecules increased the chance of Bax binding to VDAC I,leading to increased Bax-mediated apoptosis.In the presence of a static MF,LLPS was marked inhibited and HK recruitment was reduced,resulting in an increased probability of HK binding to VDAC I and a decreased probability of Bax binding to VDAC I,thus reducing Bax-mediated apoptosis.Our findings revealed a new physical mechanism for understanding magnetobiological effects from the perspective of LLPS.In addition,these results show the potential applications of physical environments,such as MFs in this study,in the treatment of LLPS-related diseases.

关键词： inhibited Apoptosis finding

Engineering classification recycling of spent lithium-ion batteries through pretreatment:a comprehensive review from laboratory to scale-up application

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第3期43卷 915-941页

作者： Shu-Xuan Yan You-Zhou Jiang Xiang-Ping chen Lu Yuan Ting-Ting Min Yu Cao wan-Li peng Tao Zhou Hunan Provincial Key Laboratory of Chemical Power Sources College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China College of Chemistry and Chemical Engineering Hunan Normal UniversityChangsha 410083China School of Public Policy and Management Tsinghua UniversityBeijing 100084China China Nonferrous Metal Industry's Foreign Engineering and Construction Co. LtdBeijing 100029China

The lithium-ion batteries(LIBs)have been widely equipped in electric/hybrid electric vehicles(EVs/HEVs)and the portable electronics due to their excellent electrochemical performances.However,a large number of retired LIBs that consist of toxic substances(e.g.,heavy metals,electrolytes)and valuable metals(e.g.,Li,Co)will inevitably flow into the waste stream,and their incineration or landfill treatment will cause severe risks to ecosystem and human beings.The sustainable and efficient treatment or recycling of valuable resources from spent LIBs should be fully recognized for environmental and resource security.As one of the most important processes for spent LIBs recycling,the pretreatment is an indispensable step,which is directly related to the subsequent metal extraction and separation processes.Although considerable progresses have been made regarding the pretreatment technologies,there are few summarized reports concerning critical processes of spent LIBs recycling,especially combination of currently available recycling technologies with industrialized applications during pretreatments.Therefore,comprehensive review of the current prevailing pretreatment technologies in laboratory to existing scale-up applications is quite necessary to reveal cutting-edge development in the field of pretreatment.In this review,the current pretreatment technologies are systematically categorized and introduced,along with critical discussions.This review focused on the various options for pretreatment processes itself,instead of general spent LIBs recycling technologies without the focused topics that have been sophisticatedly reviewed by previous studies.Here,the deactivation,discharge,dismantling,separation,liberation of active material and electrolyte treatment have been summarized with the in-depth discussion of the technology development and current status of each category.Finally,current states of industrial development are also reviewed and discussed for the development of efficient and environmentally friendly recyclin

关键词： Spent lithium-ion batteries(LIBs) Recycling Pretreatment Valuable metals Cutting-edge technologies Industrialized application