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Monte Carlo Simulation of Laser-Ablated Particle Splitting Dynamic in a low pressure Inert Gas

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Plasma Science and Technology 2016年第6期18卷 641-646页

作者：丁学成张子才梁伟华褚立志邓泽超王英龙 College of Physics Science and Technology Hebei University

A Monte Carlo simulation method with an instantaneous density dependent meanfree-path of the ablated particles and the Ar gas is developed for investigating the transport dynamics of the laser-ablated particles in a low pressure inert *** ablated-particle density and velocity distributions are *** force distributions acting on the ablated particles are *** influence of the substrate on the ablated-particle velocity distribution and the force distribution acting on the ablated particles are *** Monte Carlo simulation results approximately agree with the experimental data at the pressure of 8 Pa to 17 *** is helpful to investigate the gas phase nucleation and growth mechanism of nanoparticles.

关键词： ablated particles Monte Carlo simulation transport dynamic instantaneous mean-free-path low pressure

Thickening and Rheological Properties of Crystalline Polyester Used in low pressure Sheet Molding Compounds

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Chinese Journal of Mechanical Engineering 2011年第3期24卷 452-459页

作者： LI Jian HUANG Zhixiong ZHANG Kai Department of Materials Engineering Hubei University of Automotive Technology Shiyan 442002 China School of Materials Science andEngineering Wuhan University of Technology Wuhan 430070 China Wuhan Institute of Marine Electric Propulsion CSIC712 Wuhan 430064 China

low pressure sheet molding compound （LPMC,1.0-3.0 MPa,95-103 ℃） is a new kind of thermosetting material with crystalline polyester as a physical *** is different from conventional SMC using an earth oxide thickening agent （***） as chemical thickenner,it relies on the physical thickening of crystalline *** polyester resin is the key material to mold LPMC *** there was no report about the thickening mechanism of crystalline polyester in *** this article,crystalline polyester resins,whose melting points were between 45 ℃ and 89 ℃,were synthesized by a two-step *** melt points of crystalline polyesters are controlled by regulating the mol ratio of the two glycols and the two *** by means of varying the content of crystalline polyester resin,the thickening effect on resin paste is *** addition,the thickening mechanism of crystalline polyester in LPMC was investigated by FTIR and DSC *** effects of the diameters and viscosity of crystalline polyester on the rheological property and fiber distribution of LPMC sheets were studied,*** show that the thickening effect is excellent when the weight content of crystalline polyester resin is 3%.And there exists three kinds of functions acting in the process of thickening：swelling,hydrogen bonds and induction *** the preparing process of resin paste in LPMC,the temperature of resin paste must be kept at 90 ℃.In addition,crystalline polyester make LPMC have a perfect fluid *** the viscosity of LPMC sheet is beyond 1 kPa s,the fiber orientation is not *** when the viscosity of LPMC sheet is about 500 Pa s,the fiber shows a certain degree of *** the study of physical and chemical thickening mechanism of crystalline polyester and the rheological discipline of LPMC sheets in the hot mould will provide the researchers and enterprises with theory guidance.

关键词： low pressure low pressure sheet molding compound (LPMC) thickening mechanism rheological property fiber distribution

Study of vortex in flow fields induced by surface dielectric barrier discharge actuator at low pressure based on Q criterion

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Plasma Science and Technology 2018年第1期20卷 41-46页

作者：张政车学科聂万胜李金龙郑体凯李亮陈庆亚郑直 Equipment Academy

Flow fields induced by a surface dielectric barrier discharge actuator at low pressure of 7 kPa are measured by particle image velocimetry. The distribution of local vortices in the flow field is revealed by the Q criterion. The reason for the generation of vortices is analyzed and the influence of pulse frequency and duty cycle on vortices is studied. The results show that the Q criterion can reveal the small-scale vortices, which cannot be indicated by the streamline. The direction transition zone where the induced jet moves from the vertical to the tangential and the shear layer between the jet and stationary air are prone to the generation of strong vortices. The influence of pulse frequency on vortices is not obvious, but the variation of duty cycle can significantly affect the strength and distribution of vortices.

关键词： low pressure SDBD induced field Q criterion vortex

Silicon Epitaxial Wafer for X Band Double Read－type DDR IMPATT Diodes by Atmosphere／low pressure Growth Techniqt

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Rare Metals 1994年第3期13卷 211-213页

作者：王向武陆春一南京电子设备所江苏南京 210016 南京电子设备所江苏南京

The silicon epitaxial wafter for X band double Read-type DDR IMPATT diodes has been fabricatedby normal-low pressure growth technique. The hyperabrupt impurity profile and very thin p-layer, n-layerwere achieved.

关键词： Si Epitaxy Multilayer X band DDR IMPATT low pressure Au-todoping Autodilution

Robust Co_(3)O_(4)nanocatalysts supported on biomass-derived porous N-doped carbon toward low-pressure hydrogenation of furfural

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Frontiers of Materials Science 2023年第2期17卷 155-168页

作者： Lin Zhang Lanlan Cheng Yechen Hu Qingguang Xiao Xiufang Chen Wangyang Lu National Engineering Lab for Textile Fiber Materials&Processing Technology(Zhejiang) Zhejiang Sci-Tech UniversityHangzhou 310018China

The catalytic conversion of biomass platform chemicals using abundant non-noble metal nanocatalysts is a challenging ***,high-density cobalt oxide nanoparticles loaded on biomass-derived porous N-doped carbon(NC)was fabricated by a tandem hydrothermal pyrolysis and mild nitrate decomposition process,which is a green and cheap preparation *** Co_(3)O_(4) nanoparticles with the average size of 12 nm were uniformly distributed on the porous *** nanocomposites also possessed large surface area,high N content,good dispersibility in isopropanol,and furfural *** to these characteristics,the novel cobalt nanocatalyst exhibited high catalytic activity for producing furfuryl alcohol,yielding 98.7%of the conversion and 97.1%of the selectivity at 160℃ for 6 h under 1 bar *** control experiments implied that both direct hydrogenation and transfer hydrogenation pathways co-existed in the hydrogenation *** excellent catalytic activity of Co_(3)O_(4)@NC was attributed to the cooperative effects of porous NC and Co_(3)O_(4) *** approach provides a new idea to design effective high-density nonnoble metal oxide nanocatalysts for hydrogenation reactions,which can make full use of sustainable natural biomass.

关键词： biomass N-doped carbon cobalt oxide nanoparticle hydrogenation reaction low pressure

low pressure vapor-liquid equilibrium validation with special pseudo-components

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Low pressure vapor-liquid equilibrium validation with specia...

Self-organized pattern on the surface of a metal anode in low-pressure DC discharge

第36届中国控制会议

作者： Pan He Jizheng Chu College of Information Science and Technology Beijing University of Chemical Technology

ISBN: (纸本)9781538629185

For simplified dynamic simulation of operations of multiple feed stream and feed changes in petroleum distillation,petroleum oil and their distillation products are characterized with special pseudocomponents（SPCs）.A stock or product,characterized by SPCs with invariant physicochemical properties defined in pairs of light and heavy oil cuts of narrow boiling range,is treated as mixtures of defined *** this paper,the feasibility of SPCs on low vapor-liquid equilibrium（VLE）model is verified by vapor pressure *** procedures for both SPCs and CPCs are described,and the consistency of SPCs and CPCs representing substance entities for vapor pressure are verified through calculations with petroleum.

关键词： vapor-liquid equilibrium vapor pressure low pressure petroleum pseudocomponent

来源： cnki会议评论

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Plasma Science and Technology 2018年第3期20卷 63-71页

作者：杨亚奇李卫国 College of Electrical Engineering North China Electric Power University Beijing 102206 People's Republic of China

Self-organization phenomena on the surface of a metal electrode in low-pressure DC discharge is studied. In this paper, we carry out laboratory investigations of self-organization in a lowpressure test platform for 100–200 mm rod-plane gaps with a needle tip, conical tip and hemispherical tip within 1–10 k Pa. The factors influencing the pattern profile are the pressure value, gap length and shape of the electrode, and a variety of pattern structures are observed by changing these factors. With increasing pressure, first the pattern diameter increases and then decreases. With the needle tip, layer structure, single-ring structure and double-ring structure are displayed successively with increasing pressure. With the conical tip, the ring-like structure gradually forms separate spots with increasing pressure. With the hemispherical tip, there are anode spots inside the ring structure. With the increase of gap length, the diameter of the selforganized pattern increases and the profile of the pattern changes. The development process of the pattern contains three key stages： pattern enlargement, pattern stabilization and pattern shrink.

关键词： self-organized pattern low pressure DC voltage metal anode pattern profile

Drift characteristics and the multi-field coupling stress mechanism of the pantograph-catenary arc under low air pressure

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Chinese Physics B 2023年第4期32卷 493-503页

作者：许之磊高国强钱鹏宇肖嵩魏文赋杨泽锋董克亮马亚光吴广宁 School of Electrical Engineering Southwest Jiaotong UniversityChengdu 610031China Research and Development Department Chengdu Guojia Electrical Engineering Co.LtdChengdu 611756China

The fault caused by a pantograph-catenary arc is the main factor that threatens the stability of high-speed railway energy ***-catenary arc vertical drift is more severe than the case under normal pressure,as it is easy to develop the rigid busbar,which may lead to the flashover occurring around the support *** establish a pantograph-catenary arc experiment and diagnosis platform to simulate low pressure and strong airflow ***,the variation law of arc drift height with time under different air pressures and airflow velocities is ***,arc drift characteristics and influencing factors are *** physical process of the arc column drifting to the rigid busbar with the jumping mechanism of the arc root on the rigid busbar is *** order to further explore the mechanism of the above physical process,a multi-field stress coupling model is built,as the multi-stress variation law of arc is quantitatively *** dynamic action mechanism of multi-field stress on arc drifting characteristics is explored,as the physical mechanism of arc drifting under low pressure is theoretically *** research results provide theoretical support for arc suppression in high-altitude areas.

关键词： pantograph-catenary arc low pressure multi-field stress coupling model arc column drift

Direct synthesis of dimethyl carbonate from CO2 and methanol under low pressure

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Direct synthesis of dimethyl carbonate from CO2 and methanol...