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formation and impact-induced separation of tandem EFPs

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Defence Technology（防务技术） 2020年第3期16卷 668-677页

作者： Hong-bing Ma Yuan-feng Zheng Hai-fu Wang Chao Ge Cheng-hai Su State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

The formation and separation behaviors of tandem EFPs are studied by the combination of experiments and simulations.The results show that different formation and separation processes can be obtained by adjusting the double-layer liners,and simulations agree with experiments well.Then,the interaction process between the two liners is discussed in details,and the formation and separation mechanism are revealed.It can be found that there are four phases in the formation and separation processes,including impact phase,propulsion phase,slide phase and free flight phase.During the impact phase,the velocities of two liners rise in turns with kinetic energy exchange.In the propulsion phase,the axial impact becomes insignificant,but the radial interaction between two liners influences the appearance of tandem EFPs.Meanwhile,it should be mentioned that the inner surface of foregoing EFP remains to be in contact with the outer surface of following EFP in the propulsion phase,and the following one would continue to push the foregoing one for about 10μ to 20 μs,causing the velocities of following and foregoing EFPs gradually decreasing and increasing respectively.In the slide phase,an obvious relative movement occurs between the two EFPs,and there would be barely kinetic energy exchange.Then,the two EFPs separate gradually and get into the phase of free flight.Generally,if the outer and inner liners have the same thickness,the outer copper-inner copper liners form two long EFPs,the outer copper-inner steel liners become a foregoing short steel EFP and a following long copper EFP,and the outer steel-inner copper liners produce a foregoing long copper EFP and a following conical steel EFP.In addition,thickness match also has an important impact on formation appearance and separation process for both outer copperinner copper liners and outer steel-inner copper liners.With the thickness ratio of outer liner to inner liner decreasing,the length and length-diameter ratio of both foregoing and following EFPs increase gradually.

关键词： Shaped charge Liner Tandem EFPs formation Separation

Mesoscale study on explosion-induced formation and thermochemical response of PTFE/Al granular jet

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Defence Technology（防务技术） 2023年第5期23卷 112-125页

作者： Yuan-feng Zheng Zhi-jian Zheng Guan-cheng Lu Hai-fu Wang Huan-guo Guo State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China

The dynamic formation,shock-induced inhomogeneous temperature rise and corresponding chemical reaction behaviors of PTFE/Al reactive liner shaped charge jet(RLSCJ)are investigated by the combination of mesoscale simulation,reaction kinetics and chemical energy release test.A two-dimensional granular model is developed with the randomly normal distribution of aluminum particle sizes and the particle delivery program.Then,the granular model is employed to study the shock-induced thermal behavior during the formation and extension processes of RLSCJ,as well as the temperature history curves of aluminum particles.The simulation results visualize the motion and temperature responses of the RLSCJ at the grain level,and further indicate that the aluminum particles are more likely to gather in the last two-thirds of the jet along its axis.Further analysis shows that the shock,collision,friction and deformation behaviors are all responsible for the steep temperature rise of the reactive jet.In addition,a shock-induced chemical reaction extent model of RLSCJ is built based on the combination of the Arrhenius model and the Avrami-Erofeev kinetic model,by which the chemical reaction growth behavior during the formation and extension stages is described quantitatively.The model indicates the reaction extent highly corresponds to the aluminum particle temperature history at the formation and extension stages.At last,a manometry chamber and the corresponding energy release model are used together to study the macroscopic chemical energy release characteristics of RLSCJ,by which the reaction extent model is verified.

关键词： Reactive materials Shaped charge Mesoscale simulation formation Thermochemical response

formation of mono-dispersed droplets with electric periodic dripping regime in electrohydrodynamic(EHD) atomization

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Chinese Journal of Chemical Engineering 2020年第5期28卷 1241-1249页

作者： Zhentao Wang Qisi Wang Yaosheng Zhang Yimin Jiang Lei Xia School of Energy and Power Engineering Jiangsu UniversityZhenjiang 212013China

The formation of controllable size and dripping frequency in electrohydrodynamic(EHD)atomization with electric periodic dripping regime are of much interest and importance because of significant and wide applications,such as micro-encapsulation and ink-printing.In the present study,the experimental and theoretical works were carried out to explore droplet formation in periodic dripping regime in presence of an electric field.The dimensionless electric charge carried by each droplet produced is smaller than the 50%of critical value of the Rayleigh limit,where charge-to-mass ratio of droplets was obtained through the deflection distance in the presence of an electric field.The droplet in electric periodic dripping regime usually undergoes oscillating deformation,and finally forms a spherical droplet below the tip no more than ten times out diameter of tube.The droplet size tens of microns to one hundreds of microns decreases with an increase in applied potential.In the electric dripping mode,droplets size is independent of flow rate and affected by flow rate due to adsorption of surface active species in micro-dripping.The simplified model to predict droplets size was derived from the balance of electric,surface tension and gravity forces.The droplets size calculated in good agreement with the experiments.Meanwhile,the dripping frequency of droplets with rang of a few to several hundred hertz obtained from timeresolved images is highly dependent of liquid flow rate and electric potential.The largest dripping frequency was predicted and in reasonable agreement with the experimental results.In electric periodic dripping regime drop-on-demand droplets in size and dripping frequency further our understanding on the formation of identical droplets and are beneficial to many practical applications.

关键词： Electric field Electric periodic dripping formation Diameter Dripping frequency

formation Mechanism and Numerical Model of Quartz in Fine-Grained Organic-Rich Shales: A Case Study of Wufeng and Longmaxi formations in Western Hubei Province, South China

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Journal of Earth Science 2020年第2期31卷 354-367页

作者： Bao Zhang Detian Yan Hassan Jasmine Drawarh Xiangrong Yang Jin He Liwei Zhang Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education China University of GeosciencesWuhan 430074China

The difference in quartz types in shales not only affects the porosity and permeability of the rocks,but also reflects the difference in the sedimentary environments.We established the formation mechanism and numerical model of quartz in shales of Wufeng and Longmaxi formations in the Wangjiawan Section,South China,based on thin-section studies using SEM(scanning electron microscope),SEM-CL(cathodoluminescence),XRD(X-ray diffraction)and geochemical analyses.There are two types of quartz in the shales:detrital quartz and authigenic quartz.Detrital quartz is mostly silt-size,typically ranging from 10 to 60μm in size and subangular to angular monocrystal in shape,and brighter than authigenic quartz by CL intensity;authigenic quartz is present in two phases in shape:grain overgrowths and crystallite grains.Overgrowth surfaces are subhedral.Crystallite grains are typically less than 10μm in size,euhedral or subhedral monocrystal in shape.Authigenic quartz can be subdivided into biogenic quartz and clay mineral transformed quartz according to the source of silicon.In the numerical model,the content of detrital quartz is relatively consistent(20%);the content of biogenic quartz ranges from 40%to 70%,with a sharp fall(0–30%)in the Guanyinqiao mudstone.During the Katian,a lower anoxic and dense water column make the dissolution of biogenic silica well preserved.Biogenic quartz is the major contributor to the sediment.During the early Hirnantian interval,due to the drop of sea level and the oxygenation of seafloor,the sediment is mainly composed of clay transformed quartz and detrital quartz.During the latest Hirnatian and Rhuddanian,rapid sea level rise and anoxic ocean enhance the preservation of the biogenic silica,thereby biogenic quartz re-emerges as the major contributors to the sediment.Authigenic crystallite grains and grain overgrowths have filled in primary pore space and have decreased the interparticle porosity,however,as a rigid framework,they can suppress compaction and maintain the internal pore structure.Th

关键词： brittle mineral quartz Wufeng and Longmaxi formations formation mechanism numerical simulation

Output formation tracking for networked systems with limited energy and aperiodic silence

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Chinese Journal of Aeronautics 2022年第7期35卷 274-288页

作者： Jin JIN Junlong LI Donghao QIN Ning CAI School of Electrical Engineering Northwest Minzu UniversityLanzhou 730030China Key Laboratory of China’s Ethnic Languages and Information Technology for Ministry of Education Northwest Minzu UniversityLanzhou 730000China School of Missile Engineering Rocket Force University of EngineeringXi’an 710025China School of Artificial Intelligent Beijing University of Posts and TelecommunicationsBeijing 100876China

For leader-following networked systems with the topology switching and the aperiodic silence,limited-energy output formation tracking problems are investigated.Firstly,a new output formation tracking control protocol is proposed,which contains two components associated with the communication interactions between the leader and tracking intelligent agents and the communication interactions among tracking intelligent agents,respectively,and the aperiodic silence,the topology switching and the energy constraint index is introduced properly.Then,a two-step transformation method is presented to separate the whole dynamics of a networked system into the relative dynamics between the leader and tracking intelligent agents and the dynamics of the leader,and sufficient conditions for limited-energy output formation tracking for networked systems with limited energy and aperiodic silence are presented,which are extended into networked systems without the aperiodic silence.Especially,a partition checking algorithm is presented to check limitedenergy output formation tracking design criteria.Finally,a numerical example is illustrated to demonstrate the validness of theoretical results.

关键词： Energy calculations formation Intermittent working Networked control system Tracking

Communication-Aware formation Control of AUVs With Model Uncertainty and Fading Channel via Integral Reinforcement Learning

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IEEE/CAA Journal of Automatica Sinica 2023年第1期10卷 159-176页

作者： Wenqiang Cao Jing Yan Xian Yang Xiaoyuan Luo Xinping Guan the Institute of Electrical Engineering Yanshan UniversityQinhuangdao 066004China IEEE the Institute of Information Science and Engineering Yanshan UniversityQinhuangdao 066004China the Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China

Most formation approaches of autonomous underwater vehicles(AUVs)focus on the control techniques,ignoring the influence of underwater channel.This paper is concerned with a communication-aware formation issue for AUVs,subject to model uncertainty and fading channel.An integral reinforcement learning(IRL)based estimator is designed to calculate the probabilistic channel parameters,wherein the multivariate probabilistic collocation method with orthogonal fractional factorial design(M-PCM-OFFD)is employed to evaluate the uncertain channel measurements.With the estimated signal-to-noise ratio(SNR),we employ the IRL and M-PCM-OFFD to develop a saturated formation controller for AUVs,dealing with uncertain dynamics and current parameters.For the proposed formation approach,an integrated optimization solution is presented to make a balance between formation stability and communication efficiency.Main innovations lie in three aspects:1)Construct an integrated communication and control optimization framework;2)Design an IRL-based channel prediction estimator;3)Develop an IRL-based formation controller with M-PCM-OFFD.Finally,simulation results show that the formation approach can avoid local optimum estimation,improve the channel efficiency,and relax the dependence of AUV model parameters.

关键词： Autonomous underwater vehicles(AUVs) communication-aware formation reinforcement learning uncertainty

formation Mechanism and Sedimentary Pattern of Abandoned Channels

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Acta Geologica Sinica(English Edition) 2020年第2期94卷 545-555页

作者： LIU Zongbao SHANG Yunzhi ZHAO Rongsheng LIU Fang XUE Xinyu LIU Yunyan Northeast Petroleum University DaqingHeilongjiang 163318China Daqing Oilfield Limited Liability Company DaqingHeilongjiang 163514China Jilin University Changchun 130061China

Accurately identifying and quantitatively describing abandoned channels in meandering rivers are of great significance for improving hydrocarbon recovery. By using modern deposition analogy, field outcrop analysis, a dense well spacing, core observations and a review of the literature, this paper studied the formation process and space–time amalgamation of abandoned channels in meandering river. The results reveal that formation mechanisms of abandoned channels include chute cutoff patterns(shoal-cutting, ditch-scouring and embayment-eroding patterns) and neck cutoff patterns. The chute cutoff pattern forms a gradually abandoned channel, while the neck cutoff pattern forms a suddenly abandoned channel. From upstream to downstream, the sedimentary pattern of the abandoned channel transforms from a chute cutoff pattern to a neck cutoff pattern, where the main controlling factors transition from the grain size and gradient to the flow and vegetation. An abandoned channel formed by a chute cutoff pattern consists mainly of siltstone, fine sandstone and thin gravel layers, which form a lithological-physical barrier. The abandoned channel formed by a neck cutoff pattern consists mainly of mudstone and argillaceous siltstone, forming a lithological barrier. Based on the amalgamation and structure of the reservoir architectural elements, the abandoned channel can be divided into three planar sedimentary patterns(crescent, semilune and horseshoe) for a single channel and five vertical sedimentary patterns for composite channels.

关键词： abandoned channel cutoff pattern formation mechanism sedimentary pattern meandering river

Identification of the HAK gene family reveals their critical response to potassium regulation during adventitious root formation in apple rootstock

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Horticultural Plant Journal 2023年第1期9卷 45-59页

作者： Muhammad Mobeen Tahir Lu Tong Lingling Xie Tong Wu Muhammad Imran Ghani Xiaoyun Zhang Shaohuan Li Xiuhua Gao Leeza Tariq Dong Zhang Yun Shao Yangling Sub-Center of National Center for Apple Improvement College of HorticultureNorthwest Agriculture&Forestry UniversityYanglingShaan 712100China The Key Laboratory of Special Fruits and Vegetables Cultivation Physiology and Germplasm Resources Utilization in Xinjiang Production and Construction Group College of AgricultureShihezi UniversityShiheziXinjiang 832003China Centre of Excellence in Molecular Biology University of the PunjabLahore 53700Pakistan

Adventitious root formation is a bottleneck during vegetative proliferation.Potassium(K^(+))is an essential macronutrient for plants.K^(+)accumulation from the soil and its distribution to the different plant organs is mediated by K^(+)transporters named K^(+)transporter(KT),K^(+)uptake(KUP),or high-affinity K^(+)(HAK).This study aimed to identify members of the HAK gene family in apples and to characterize the effects of K^(+)supply on adventitious root formation and on the expression of HAK genes and the genes that putatively control auxin transport,signaling,and cell fate during adventitious root formation.In this study,34 HAK genes(MdHAKs)were identified in the apple(Malus×domestica‘Golden Delicious’)genome.A phylogenetic analysis divided MdHAKs into four clusters(Ⅰ,Ⅱ,Ⅲ,andⅣ),comprising 16,1,4,and 13 genes,respectively.The syntenic relationships revealed that 62.5%of the total MdHAK genes arise from genomic duplication events.Chromosome location,domain structure,motif analysis,and physico-chemical characteristics were subsequently investigated.Furthermore,the application of K^(+)indicated the emergence of adventitious roots at 8 d and produced more adventitious roots at 16 d than the K^(+)-free control(CK)treatment.In addition,various MdHAKs showed root-specific expression in B9 apple rootstock stem cuttings and enhanced expression during the initiation and emergence stages of adventitious root formation in response to K^(+)treatment.Additionally,K^(+)treatment enhanced the expression levels of MdPIN1,MdPIN2,and MdAUX1.Further data indicated that a higher expression of MdWOX11,MdLBD16,and MdLBD29 and of cell cycle-related genes contributed to the auxin-stimulated adventitious root formation in response to K^(+).

关键词： Apple rootstock Adventitious root formation Potassium(K+) HAK transporter

Effect of temperature on formation and evolution of solid electrolyte in terphase on Si@Graphite@C anodes

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Journal of Energy Chemistry 2022年第1期31卷 190-200,I0006页

作者： Hong Dong Jie Wang Peng Wang Hao Ding Ru Song Ning-Shuang Zhang Dong-Ni Zhao Li-Juan Zhang Shi-You Li College of Petrochemical Technology Lanzhou University of TechnologyLanzhou 730050GansuChina Gansu Key Laboratory of Low-Carbon Energy and Chemical Engineering Lanzhou 730050GansuChina College of Chemistry and Chemical Engineering Qinghai University for NationalitiesXining 810007QinghaiChina

Studies on the formati on and evolutio n of the solid electrolyte in terface(SEI)film under different ambient temperatures are important to understand the failure behavior of lithium-ion batteries(LIBs).Herein,in-situ electrochemical impedance spectroscopy(EIS)test is performed on the whole discharge process of Si@Graphite@C/Li cell at 0,25 and 55℃,respectively.Combining with scanning electron microscopy,transmission electron microscopy and X-ray photoelectron spectroscopy characterizations,it is found that the SEI film undergoes a complicated evolution process of pre-formation,self-improvement and gradual decay in succession at 25℃.Besides,due to the dissolution of organo-alkyl lithium at high temperature,the formed film is mainly composed of LiF,Li_(2)CO_(3) and other in organic salts,which helps to decrease the impedance.However,the electrolyte is consumed continuously on the new exposed in terface,leading to the degraded performance of the cell.Moreover,the dyn amic properties of Li^(+) ions are poor at low temperature,though the migration ability of Li^(+) ions in the solid phase can be improved as the cycle goes on.Therefore,the development and application of in-situ EIS tech no logy are expected to become an important means to explain the electrochemical performance of batteries.

关键词： In-situ EIS Solid electrolyte in terphase formation Evolution Si@Graphite@C anodes