Time-resolved spectroscopy of collinear femtosecond and nanosecond dual-pulse laser-induced Cu plasmas

In this paper,we investigate the time-resolved spectroscopy of collinear femtosecond(fs)and nanosecond(ns)dual-pulse(DP)laser-induced plasmas.A copper target was used as an experimental sample,and the fs laser was considered as the time zero reference point.The interpulse delay between fs and ns laser beams was 3μs.First,we compared the time-resolved peak intensities of Cu(I)lines from Cu plasmas induced by fs+ns and ns+fs DP lasers with collinear configuration.The results showed that compared with the ns+fs DP,the fs+ns DP laser-induced Cu plasmas had stronger peak intensities and longer lifetimes.Second,we calculated time-resolved plasma temperatures using the Boltzmann plot with three spectral lines at Cu(I)510.55,515.32 and 521.82 nm.In addition,time-resolved electron densities were calculated based on Stark broadening with Cu(I)line at 521.82 nm.It was found that compared with ns+fs DP,the plasma temperatures and electron densities of the Cu plasmas induced by fs+ns DP laser were higher.Finally,we observed images of ablation craters under the two experimental conditions and found that the fs+ns DP laser-produced stronger ablation,which corresponded to stronger plasma emission.

Construction of Vitality of Public Space in New Urban Area:A Case Study of Honggutan New District of Nanchang City

As display window of urban vitality,public space carries the colorful life of the residents living here and shows the spiritual outlook of a certain region.As a rising star,new urban area lacks historical accumulation and smell of fireworks when compared with old urban area.How to stimulate the vitality of public space in new urban area has become an unavoidable problem.In this paper,Honggutan New District of Nanchang City is taken as research object,to analyze the relationship between the representation of population vitality and the physical space in new urban area,and explore strategies for creating vitality of public space in new urban area.

Comparison of sample temperature effect on femtosecond and nanosecond laser-induced breakdown spectroscopy

In this paper,we investigated the emission spectra of plasmas produced from femtosecond and nanosecond laser ablations at different target temperatures in air.A brass was selected as ablated target of the experiment.The results indicated that spectral emission intensity and plasma temperature showed similar trend for femtosecond and nanosecond lasers,and the two parameters were improved by increasing the sample temperature in both cases.Moreover,the temperature of nanosecond laser-excited plasma was higher compared with that of femtosecond laser-excited plasma,and the increase of the plasma temperature in the case of nanosecond laser was more evident.In addition,there was a significant difference in electron density between femtosecond and nanosecond laser-induced plasmas.The electron density for femtosecond laser decreased with increasing the target temperature,while for nanosecond laser,the electron density was almost unchanged at different sample temperatures.

One stop shop IV: taxonomic update with molecular phylogeny for important phytopathogenic genera: 76-100 (2020)

This is a continuation of a series focused on providing a stable platform for the taxonomy of phytopathogenic fungi and fungus-like organisms.This paper focuses on one family:Erysiphaceae and 24 phytopathogenic genera:Armillaria,Barrio-psis,Cercospora,Cladosporium,Clinoconidium,Colletotrichum,Cylindrocladiella,Dothidotthia,,Fomitopsis,Ganoderma,Golovinomyces,Heterobasidium,Meliola,Mucor,Neoerysiphe,Nothophoma,Phellinus,Phytophthora,Pseudoseptoria,Pythium,Rhizopus,Stemphylium,Thyrostroma and Wojnowiciella.Each genus is provided with a taxonomic background,distribution,hosts,disease symptoms,and updated backbone trees.Species confirmed with pathogenicity studies are denoted when data are available.Six of the genera are updated from previous entries as many new species have been described.

Arbitrary manipulations of focused higher-order Poincare beams by a Fresnel zone metasurface with alternate binary geometric and propagation phases

The manipulation of high-quality vector beams(VBs)with metasurfaces is an important topic and has potential for classical and quantum applications.In this paper,we propose a Fresnel zone(FZ)metasurface with metallic nanoslits arranged on FZs,which sets alternate binary geometric and propagation phases to cancel the incident spin component and focus the converted spin component(CSC).The rotation designs of nanoslits transform the incident polarization state on the conventional Poincare sphere to VBs on the higher-order Poincare(HOP)sphere.The two orbital angular momentum states of the CSCs were manipulated,and the focused HOP beams were generated.The experimental results demonstrate the broadband generation of arbitrarily focused HOP beams of high quality under the illumination of the red(632.8 nm),green(532 nm),and blue(473 nm)light.This work will be of significance for the applications of VBs in different areas,such as precision metrology,optical micromanipulation,and quantum information.

Triboelectric nanogenerators for clinical diagnosis and therapy:A report of recent progress

Triboelectric nanogenerators(TENGs)are considered as an ideal platform for power harvesting for living organisms,thanks to their unique characteristics like flexibility,conversion efficient,and manufacturing cost.Recent advances in TENGs have brought innovative solutions for clinical healthcare.Particularly,TENGs offer novel solutions of continues power supply for wearable and implantable medical devices with lightweight,thinness,good biocompatibility,and excellent soft tissue conformability.In this review,we discuss(1)The working principle and representative structure of TENGs,(2)the material selection of TENGs,(3)the recent progression of application of TENG in the medical field of cardiovascular system,nervous system,respiratory system,microbial inactivation,antibiofouling,disinfection,and tissue repair,(4)challenges and future perspectives of TENG-based medical devices.The emerging TENGs and their applications in medicine cannot simply be seen as an alternative to conventional power supplies,it provides a revolutionary solution for wearable and implantable medical devices,and they will surely change the paradigm of disease diagnosis and treatment in the future.