Perfect metamaterial absorber improved laser-driven flyer

Abstract Laser driven flyer (LDF) can drive small particles to ultrahigh speed (several km/s) by feeding pulse laser light, and exhibits giant application prospect in both of the civilian and military regions, such as the ignition of missile and spacecraft and dynamic high-pressure loading. In this work, we demonstrate a high-performance LDF by using the perfect metamaterial absorber (PMA) to improve the energy utilization efficiency of light. The designed Ag nanopillar array in anodic aluminum oxide templates (APA-AAO) were skillfully fabricated in-situ on the flyer layer surface, which can greatly reduce the reflectivity from 93% of the pure Al foil flyers to about 5% of the APA-AAO enhanced flyers. Our systematically transient analysis reveals that this ultralow reflectivity, together with the well-formed metal structure on Al foil, greatly improve both of the electron temperature and sustaining time of plasma formed in the ablating layer, and further enhances the acceleration process at both of the initial detonation wave generation stage (0–10 ns) and the following thermal expansion stage (10–200 ns). The final speed of the flyer generated in the PMA-enhanced LDF approach to 1730 m/s, which is about 1.4 times larger than that (1250 m/s) of the pure Al foil flyers. The transient electron temperature, transient flyer shadowgraph, plasma sustaining time, velocity, and accelerated velocity have been investigated systematically in this work. This PMA enhanced LDF provides an effective method for obtaining high-speed microparticles, and opens up a new perspective and guidance for designing high-performance LDF.

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Future directions of material chemistry and energy chemistry

Pure and Applied Chemistry ◽

10.1515/pac-2020-1011 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Jing Cao ◽

Ding Ma ◽

Shu-Hong Yu

Keyword(s):

High Performance ◽

Fossil Fuels ◽

Research Direction ◽

Energy Utilization ◽

Utilization Efficiency ◽

Energy Structure ◽

Key Factors ◽

Material Chemistry ◽

Energy Chemistry ◽

Survival And Development

Abstract Energy is an important substantial foundation for the survival and development of humans. However, the over-consumption of resources and environmental pollution have become more prominent. The key factors for solving energy problems are to increase energy utilization efficiency and optimize energy structure. The development of new materials is the research emphasis in the field of material chemistry all the time. For instance, developing new light-capture materials and catalysts to improve the efficiency of existing photovoltaic cells is one of the most effective approaches to increasing solar power capacity radically. The design of high-performance catalytic materials to make better use of energy from fossil fuels and biomass. In addition, it is an important research direction of material chemistry and energy chemistry to deeply understand the reaction mechanism of energy conversion.

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Effect of Laser on Double-Arc Physical Characteristics in Pulsed Laser Induced Double-TIG Welding

10.21203/rs.3.rs-513454/v1 ◽

2021 ◽

Author(s):

Liming Liu ◽

Xinkun Xu ◽

Guomin Xu ◽

Zhaodong Zhang

Keyword(s):

Heat Source ◽

High Speed ◽

Pulsed Laser ◽

Physical Characteristics ◽

Particle Migration ◽

Energy Utilization ◽

Utilization Efficiency ◽

Horizontal Distance ◽

Arc Plasma ◽

Total Electron

Abstract In order to improve the energy utilization efficiency of double-TIG arc, based on the synchronous induction of pulsed laser to double-arc, the coupling-enhanced discharge phenomenon between double-arc is studied in this paper. The energy utilization efficiency of pulsed laser induced double-arc is quantitatively analyzed. The physical characteristics of coupling double-arc are studied based on high-speed camera and spectral diagnosis technology. The physical model is established to discuss the particle migration during the coupling discharge, characterizing the movement state of electrons. The results show that Dla (horizontal distance between the tungsten electrode tip and laser beam axis) has a significant effect on the energy utilization efficiency of the heat source. With the increase of Dla, there are three interaction relationships between the double-arc plasma and keyhole plasma: Mutual interference, Coupling-enhanced discharge and No interaction. A suitable Dla can realize the synchronous induction of laser to double-arc plasma, forming a coupling double-arc, the heat source has a higher energy utilization efficiency. The migration of particles in double-arc can be divided into four stages: Double-arc free discharge stage, Laser-induced initial stage, Laser-induced contraction stage and Laser-induced stable stage. Under the induction of laser, the double-arc forms a common compressed conductive channel. The energy density of coupling double-arc reaches 9.3 times that of traditional double-arc, and the total electron kinetic energy increases by 38% compared with traditional double-arc.

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Characteristics of pulsed nanosecond discharge excited by compact solid-state pulse forming line at atmospheric pressure air

Journal of Physics D Applied Physics ◽

10.1088/1361-6463/ac3e2a ◽

2021 ◽

Author(s):

Jie Li ◽

Yi Liu ◽

Xi Li ◽

Pang Dong ◽

Feixiang Liu ◽

...

Keyword(s):

Atmospheric Pressure ◽

High Speed ◽

Average Energy ◽

Energy Utilization ◽

Utilization Efficiency ◽

High Speed Photography ◽

Pulsed Plasma ◽

Streamer Discharge ◽

Equilibrium Plasma ◽

Non Equilibrium

Abstract Non-equilibrium plasma is a promising technology for the generation of ozone and removal of exhausted fuel gases. However, applications of non-equilibrium plasma are restricted by energy utilization efficiency in many industry fields. Discharge excited by nanosecond pulsed power is regarded as one of the most efficient methods. In this study, a compact 5 stages stacked blumlein pulse forming line and photoconductive semiconductor switches-based power source was introduced to generate pulsed plasma. This compact source could achieve over 50 kV with 10.1 ns pulse width and 4.8 ns pulse rising time. Coaxial cylindrical reactor was employed to generate a pulsed streamer discharge driven by the nanosecond pulsed source in atmospheric pressure air. Electrical parameters of the streamer discharge have been obtained in this study, the instantaneous power dissipation exceeds 8 MW and the average energy consumption of each pulse exceeds 56 mJ. Experiments of high speed photography have been conducted to observe the evolution process. It can be found that streamer heads start from the central wire electrode and then head to the grounded cylinder electrode in all radial direction of the coaxial electrode. Triple wire-to-cylinder electrodes discharge shows that all the three coaxial discharges develop synchronously and symmetrically, which shows that is capable of generating large volume non-equilibrium diffusive streamer discharge plasma.

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Vacuum System to Minimize the Specimen Contamination of High-Performance EM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077967 ◽

1977 ◽

Vol 35 ◽

pp. 68-69

Author(s):

N. Yoshimura ◽

K. Shirota ◽

T. Etoh

Keyword(s):

Electron Microscope ◽

High Speed ◽

High Performance ◽

High Vacuum ◽

Vacuum System ◽

Pump System ◽

Pumping System ◽

Diffusion Pump ◽

Almost All ◽

Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

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PHAX-SCAN: Functional integration of a Scanning Electron Microscope and an energy-dispersive x-ray analyser

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100152252 ◽

1989 ◽

Vol 47 ◽

pp. 56-57

Author(s):

Marc H. Peeters ◽

Max T. Otten

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

High Speed ◽

High Performance ◽

Functional Integration ◽

Energy Dispersive ◽

X Rays ◽

X Ray ◽

High Speed Analysis ◽

Scanning Electron

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.

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The bright future of digital imaging in scanning electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100149672 ◽

1993 ◽

Vol 51 ◽

pp. 768-769

Author(s):

M. T. Postek ◽

A. E. Vladar

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Digital Imaging ◽

High Speed ◽

High Performance ◽

Mass Storage ◽

Analog To Digital ◽

Central Processing ◽

Digital Imaging Technology ◽

Scanning Electron

One of the major advancements applied to scanning electron microscopy (SEM) during the past 10 years has been the development and application of digital imaging technology. Advancements in technology, notably the availability of less expensive, high-density memory chips and the development of high speed analog-to-digital converters, mass storage and high performance central processing units have fostered this revolution. Today, most modern SEM instruments have digital electronics as a standard feature. These instruments, generally have 8 bit or 256 gray levels with, at least, 512 × 512 pixel density operating at TV rate. In addition, current slow-scan commercial frame-grabber cards, directly applicable to the SEM, can have upwards of 12-14 bit lateral resolution permitting image acquisition at 4096 × 4096 resolution or greater. The two major categories of SEM systems to which digital technology have been applied are:In the analog SEM system the scan generator is normally operated in an analog manner and the image is displayed in an analog or "slow scan" mode.

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Preparative Isolation of 5 Antioxidant Constituents from the Medicinal Mushroom Phellinus baumii (Agaricomycetes) by High-Speed Countercurrent Chromatography and Preparative High-Performance Liquid Chromatography

International Journal of Medicinal Mushrooms ◽

10.1615/intjmedmushrooms.v19.i4.20 ◽

2017 ◽

Vol 19 (4) ◽

pp. 319-326 ◽

Cited By ~ 1

Author(s):

Libin Ye ◽

Hongjian Zheng ◽

Zhong Zhang ◽

Yan Yang

Keyword(s):

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

High Speed ◽

High Performance ◽

Countercurrent Chromatography ◽

Medicinal Mushroom ◽

Preparative Isolation ◽

Phellinus Baumii

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Performance Analysis of Various Multipliers Using 8T-full Adder with 180nm Technology

Recent Advances in Electrical & Electronic Engineering (Formerly Recent Patents on Electrical & Electronic Engineering) ◽

10.2174/2352096513666200107091932 ◽

2020 ◽

Vol 13 (6) ◽

pp. 864-870

Author(s):

Sai Venkatramana Prasada G.S ◽

G. Seshikala ◽

S. Niranjana

Keyword(s):

Low Power ◽

Power Dissipation ◽

High Speed ◽

High Performance ◽

Full Adder ◽

Fundamental Operation ◽

Wallace Tree ◽

Power Delay Product ◽

The Comparative Study ◽

Wallace Tree Multiplier

Background: This paper presents the comparative study of power dissipation, delay and power delay product (PDP) of different full adders and multiplier designs. Methods: Full adder is the fundamental operation for any processors, DSP architectures and VLSI systems. Here ten different full adder structures were analyzed for their best performance using a Mentor Graphics tool with 180nm technology. Results: From the analysis result high performance full adder is extracted for further higher level designs. 8T full adder exhibits high speed, low power delay and low power delay product and hence it is considered to construct four different multiplier designs, such as Array multiplier, Baugh Wooley multiplier, Braun multiplier and Wallace Tree multiplier. These different structures of multipliers were designed using 8T full adder and simulated using Mentor Graphics tool in a constant W/L aspect ratio. Conclusion: From the analysis, it is concluded that Wallace Tree multiplier is the high speed multiplier but dissipates comparatively high power. Baugh Wooley multiplier dissipates less power but exhibits more time delay and low PDP.

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Ultracompact and low-power-consumption silicon thermo-optic switch for high-speed data

Nanophotonics ◽

10.1515/nanoph-2020-0496 ◽

2020 ◽

Vol 10 (2) ◽

pp. 937-945

Author(s):

Ruihuan Zhang ◽

Yu He ◽

Yong Zhang ◽

Shaohua An ◽

Qingming Zhu ◽

...

Keyword(s):

Power Consumption ◽

Low Power ◽

High Speed ◽

High Performance ◽

Pulse Amplitude ◽

Telecommunication Networks ◽

Low Power Consumption ◽

Power Efficient ◽

High Speed Data ◽

On Chip

AbstractUltracompact and low-power-consumption optical switches are desired for high-performance telecommunication networks and data centers. Here, we demonstrate an on-chip power-efficient 2 × 2 thermo-optic switch unit by using a suspended photonic crystal nanobeam structure. A submilliwatt switching power of 0.15 mW is obtained with a tuning efficiency of 7.71 nm/mW in a compact footprint of 60 μm × 16 μm. The bandwidth of the switch is properly designed for a four-level pulse amplitude modulation signal with a 124 Gb/s raw data rate. To the best of our knowledge, the proposed switch is the most power-efficient resonator-based thermo-optic switch unit with the highest tuning efficiency and data ever reported.

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