Concave Version Printing of High-Performance Polymer THz Filters.

The development of high Q and tunable narrowband filters that can efficiently manipulate THz beams is critical for various THz applications, such as imaging and sensing. However, for filters made of metals and dielectrics, issues such as high losses, limited tunability, and lengthy process flows exist. Here, a scalable concave version reprinting technique to mass produce high-performance microstructured polymer filters is presented. The technique is extremely simple, eliminating the demand for the use of any large equipment including injection molding and thermal press printing machines, and is reliable; in the reprinted structures, there are no defects including gaps and air bubbles. The produced narrowband filters exhibit a high Q factor of 57 with wide tunability over the THz band from ∼80 to 160 µm in wavelength. The presented technique can be adopted to realize other devices as well using polymer materials with simplicity and high precision.

Ultrahigh-Q Polarization-Independent Terahertz Metamaterial Absorber Using Pattern-Free Graphene for Sensing Applications.

In contrast to noble metals, graphene exhibits significantly lower loss, especially useful for optical sensing applications that require ultrahigh Q factors, and offer wide range tunability via an adjustable Fermi level. However, precise graphene patterning is difficult, especially for large areas, severely limiting its applications. Here, a tunable terahertz metamaterial absorber (TMMA) with ultrahigh Q factors consisting of a continuous, pattern-free graphene is demonstrated. A graphene sheet is overlaid on an Al metal array, forming a structure that supports strong localized surface plasmon polaritons (LSPPs) with fields tightly confined in the graphene, minimizing loss. Theoretical results show that this TMMA exhibits an ultrahigh Q factor of 1730, a frequency sensitivity of 2.84 THz/RIU, and an excellent figure of merit (FoM) of 365.85 RIU-1, independent of polarization. A tunability from ~2.25 to ~3.25 THz is also achieved by tuning Ef of graphene from 0.3 to 0.7 eV. The proposed graphene-based TMMA holds many potential applications, particularly in the field of sensing.

Optical Upconversion in Mononuclear Lanthanide Co-Crystal Assemblies.

In this work, we developed two kinds of co-crystal assemblies systems, consisting of discrete mononuclear Yb3+ and Er3+ and mononuclear Yb3+ and Pr3+, which can achieve Er3+ and Pr3+ upconversion luminescence, respectively, by Yb3+ sensitization under 980 nm excitation. The structure and composition of two co-crystal assemblies were determined by single crystal X-ray diffraction. By investigation of the series of two assemblies, respectively, it is found that the strongest upconversion luminescence is both obtained when the molar ratio of Yb3+ and Ln3+ (Ln=Er or Pr) is 1 : 1. The energy transfer mechanism of Er3+ assemblies is determined as energy transfer upconversion, while that of Pr3+ assemblies is determined as energy transfer upconversion and cooperative sensitization upconversion. This is the first example of Pr3+ upconversion luminescence at the molecular dimension at room temperature, which enriches the research in the field of upconversion luminescence with lanthanide complexes.

Effect of biochar with various pore characteristics on heavy metal passivation and microbiota development during pig manure composting.

Understanding the porosity of biochar (BC) that promotes the heavy metal (HM) passivation during composting can contribute to the sustainable management of pig manure (PM). The current work aimed to explore the influence of BC with varying pore sizes on the physicochemical properties and morphological changes of HMs (including Zn, Cu, Cr, As, and Hg), and microbiota development during PM composting. The various pore sizes of BC were generated by pyrolyzing pine wood at 400 (T1), 500 (T2), 600 (T3) and 700 (T4) °C, respectively. The results revealed a positive correlation between specific surface area of BC and pyrolysis temperature. BC addition contributed to a significantly extended compost warming rate and duration of high-temperature period, as well as HM passivation, reflected in the decrease in Exc-Zn (63-34%) and Red-Cu (28-13%) content, and the conversion of Oxi-Cr (29-21%) and Red-Hg (16-5%) to more stable forms. Moreover, BC at T4 exhibited the best effect on Zn and Cu passivation due to the highest specific surface area (380.03 m2/g). In addition to its impact on HM passivation, BC addition improved the microbial environment during PM composting, leading to enhanced microbial diversity and richness. Notably, Chloroflexi and Bacteroidota played key roles in promoting the transformation of Exc-Cu and Red-Hg into stable forms. This phenomenon further stimulated the enhanced decomposition of organic matter (OM) when BC prepared at 600-700 °C was added. Therefore, it can be concluded that the regulation of BC porosity is an effective strategy to improve HM passivation and the overall effectiveness of PM composting.

Using Mapping Knowledge Domains to analyze research status, hotspots and frontier evolution of school health in China / 中国学校卫生

Objective@#To reveal intuitively the micro and macro structure of school health research in China, in order to lay a solid foundation for further study.@*Methods@#Statistical analyses the current status of 864 high-level journal papers in the field of school health in China by EXCEL and SATI software, author cooperation and organization cooperation, research hotspots and frontier trend knowledge maps were drawn by Citespace.@*Results@#The research in the field of school health in China shows a wavy growth trend, the contribution of Chinese Journal of School Health is the biggest(757). Ma Jun, Tao Fangbiao, Wang Zhiyong, Liu Wei, Duan Jiali, Xu Yong are high-yield authors, Peking University, Anhui Medical University, Dalian City and Beijing Center for Disease Control and Prevention are high-yield institutions. Author cooperation and institutional cooperation are relatively loose, and Duan Jiali et al. and Peking University institute of child and adolescent health, respectively, form the largest cooperation community. Status, supervision, rural area, management, surveillance, health education, epidemiology, nutrition, environmental health, infectious diseases, common diseases, and influencing factors, etc. are hot topics in the field.@*Conclusion@#Cross-boundary exchanges and cooperation should be strengthened to promote regional coordinated development. Health risk behaviors of children and adolescents, environmental health surveillance and epidemiology of infectious diseases of primary and secondary schools, the school health personnel present situation investigation, children nutrition health and common diseases prevention and control, rural school health supervision and health education countermeasures, and school health management model were the hot topics, prevention of child injury, Internet addiction, and physical and mental health promotion were the leading directions. The commnunication and cooperation between different fields should be strengthened to improve the reginal development.