Intelligently Counting Agricultural Pests by Integrating SAM with FamNet

The utilization of the large pretrained model (LPM) based on Transformer has emerged as a prominent research area in various fields, owing to its robust computational capabilities. However, there remains a need to explore how LPM can be effectively employed in the agricultural domain. This research aims to enhance agricultural pest detection with limited samples by leveraging the strong generalization performance of the LPM. Through extensive research, this study has revealed that in tasks involving the counting of a small number of samples, complex agricultural scenes with varying lighting and environmental conditions can significantly impede the accuracy of pest counting. Consequently, accurately counting pests in diverse lighting and environmental conditions with limited samples remains a challenging task. To address this issue, the present research suggests a unique approach that integrates the outstanding performance of the segment anything model in class-agnostic segmentation with the counting network. Moreover, by intelligently utilizing a straightforward TopK matching algorithm to propagate accurate labels, and drawing inspiration from the GPT model while incorporating the forgetting mechanism, a more robust model can be achieved. This approach transforms the problem of matching instances in different scenarios into a problem of matching similar instances within a single image. Experimental results demonstrate that our method enhances the accuracy of the FamNet baseline model by 69.17% on this dataset. Exploring the synergy between large models and agricultural scenes warrants further discussion and consideration

Effect of background ionization on plasma ignition dynamics

The influence of background ionization on the ignition dynamics of the pulsed plasma plume is studied. The ignition delay time of each pulse is investigated by recording the voltage signal and the light emission signal. By changing the frequency, the relationship between the pulse-off time and the ignition delay time is revealed. This indicates that residual active species produced in the previous discharge play a role in the next one. With the decrease in the frequency, both time delay and ignition delay time increase. This is due to the decay of the reactive species densities in the pulse-off time. Lower concentrations of these species lead to a longer ignition delay time. The functions for calculating the ignition delay time are utilized to explain the effect of residual species. The independent data of each discharge also evidence the impact of the previous pulse. The exotic relationship between the ignition delay times of the first two pulses may be due to the electrode configuration used in this work. For a pin-to-plane electrode structure, the active species produced during the breakdown are accumulated around the anode (pin-point) where the discharge initiated for the asymmetrical electric field distribution

Visible light effects in plasma plume ignition

The breakdown delay time of a closed plasma plume excited by a high-voltage pulse is investigated. The visible monochromatic light of 404, 532, and 662 nm wavelength and narrow-waveband light at a central wavelength of 400, 430, 450, 470, 500, 530, 570, 610, and 630 nm are used to pre-ionize the gas. It is found that the breakdown delay time decreases when the visible light illuminates the discharge tube. The light is most effective when it is applied at the position near the high-voltage electrode. Besides, the tube material and size are important for enhancing the effect. The jet using quartz tube and larger inner diameter make the effect stronger. The effect of visible light is found to inversely relate to the wavelength, manifested by the longer breakdown delay times for longer wavelengths. With increasing the frequency and the pulse width of the voltage, the visible light shortens the delay time more effectively. These observations can be explained by the visible light-enhanced generation of free electrons before the ignition. The proposed mechanisms of free-electron generation are the optically stimulated exoelectron emission from the inner surface of the discharge tube wall and the vibrational excitation of nitrogen molecules. The effects of visible light weaken with the addition of oxygen as a result of electron affinity to oxygen

From short pulses to short breaks: exotic plasma bullets via residual electron control

Plasma plumes with exotically segmented channel structure and plasma bullet propagation are produced in atmospheric plasma jets. This is achieved by tailoring interruptions of a continuous DC power supply over the time scales of lifetimes of residual electrons produced by the preceding discharge phase. These phenomena are explained by studying the plasma dynamics using nanosecond-precision imaging. One of the plumes is produced using 2-10μs interruptions in the 8kV DC voltage and features a still bright channel from which a propagating bullet detaches. A shorter interruption of 900ns produces a plume with the additional long conducting dark channel between the jet nozzle and the bright area. The bullet size, formation dynamics, and propagation speed and distance can be effectively controlled. This may lead to micrometer-and nanosecond-precision delivery of quantized plasma bits, warranted for next-generation health, materials, and device technologies

Film formation from plasma-enabled surface-catalyzed dehalogenative coupling of a small organic molecule

This work demonstrates a new pathway to the direct on-surface fabrication of surface coatings by showing that application of a plasma can lead to dehalogenative coupling of small aromatic molecules at a catalytic surface. Specifically, we show that a room temperature, atmospheric pressure plasma can be used to fabricate a coating through a surface-confined dehalogenation reaction. Plasma treatments were performed using a dielectric barrier discharge (DBD) technique under pure nitrogen with a variety of power levels and durations. Samples were analysed by optical and helium ion microscopy (HIM), X-ray photoelectron spectroscopy (XPS), optical profilometry, and contact angle measurement. By varying the plasma parameters we could control the chemistry, morphology and roughness of the film. Surface wettability also varied with the plasma parameters, with high-dose plasmas leading to a hydrophobic surface with water contact angles up to 130°