Change of Rice Paddy and Its Impact on Human Well-Being from the Perspective of Land Surface Temperature in the Northeastern Sanjiang Plain of China

Large-scale and high-speed paddy land expansion has appeared in Northeast China since the 21st century, causing the change in land surface temperature. The lack of continuous investigation limits the exploration of discoveries in this region. To address this limitation, a collaborative approach that combined human–computer interaction technology, gravity center model and spatial analysis was established. It provided some new findings in spatiotemporal evolution, migration trajectory and surface cooling effect of the paddy field in Northeastern Sanjiang Plain, a center of paddy field planting in China. The results show that: (1) A sustained paddy expansion was monitored, with a total area ranging from 2564.58 km2 to 11430.94 km2, along with a rate of growth of 345.72% from 2000 to 2020. Correspondingly, its reclamation rate changed to 47.53% from 10.66%, showing the improved planting level of the paddy field. (2) Gravity center of paddy field continued to be revealed northward with a 5-year interval from 2000 to 2020. Migration distance of the straight line reached 23.94 km2, with the direction offset of 27.20° from east to north. (3) Throughout the growing season of crops, the land surface temperature of paddy field was 27.73°, 29.38°, 27.01°, 25.62° and 22.97° from May to October; and the cooling temperature effect of paddy field was investigated, with the reduced values of 0.61°, 0.79° and 1.10° in the low-, medium- and high-paddy field density regions from 2000 to 2020, respectively. Overall, these new findings in the cold temperate zone, high latitude region of the Northern Hemisphere, provided the reference for the investigation of paddy field monitoring and its environmental effects in China and other regions

Enhancement of Mass Transfer Process for Photocatalytic Reduction in Cr(VI) by Electric Field Assistance

The removal of Cr(VI), a highly-toxic heavy metal, from industrial wastewater is a critical issue in water treatment research. Photocatalysis, a promising technology to solve the Cr(VI) pollution problem, requires urgent and continuous improvement to enhance its performance. To address this need, an electric field-assisted photocatalytic system (PCS) was proposed to meet the growing demand for industrial wastewater treatment. Firstly, we selected PAF-54, a nitrogen-rich porous organic polymer, as the PCS’s catalytic material. PAF-54 exhibits a large adsorption capacity (189 mg/g) for Cr(VI) oxyanions through hydrogen bonding and electrostatic interaction. It was then coated on carbon paper (CP) and used as the photocatalytic electrode. The synergy between capacitive deionization (CDI) and photocatalysis significantly promotes the photoreduction of Cr(VI). The photocatalytic performance was enhanced due to the electric field’s influence on the mass transfer process, which could strengthen the enrichment of Cr(VI) oxyanions and the repulsion of Cr(III) cations on the surface of PAF-54/CP electrode. In addition, the PCS system demonstrates excellent recyclability and stability, making it a promising candidate for chromium wastewater treatment

Feasibility Study of Single-Crystal Si Island Manufacturing by Microscale Printing of Nanoparticles and Laser Crystallization

Nonvacuum printing of single crystals would be ideal for high-performance functional device (such as electronics) fabrication yet challenging for most materials, especially for inorganic semiconductors. Currently, the printed films are dominant in amorphous, polycrystalline, or nanoparticle films. In this article, manufacturing of single-crystal silicon micro/nano-islands is attempted. Different from traditional vapor deposition for silicon thin-film preparation, silicon nanoparticle ink was aerosol-printed followed by confined laser melting and crystallization, allowing potential fabrication of single-crystal silicon micro/nano-islands. It is also shown that as-fabricated Si islands can be transfer-printed onto polymer substrates for potential application of flexible electronics. The additive nature of this technique suggests a scalable and economical approach for high-crystallinity semiconductor printing

Risk factors associated with the prevalence of neck and shoulder pain among high school students: a cross-sectional survey in China

Abstract Background After the COVID-19 outbreak, many Chinese high school students have increased their dependence on electronic devices for studying and life, which may affect the incidence of neck and shoulder pain (NSP) in Chinese adolescents. Methods To evaluate the prevalence of NSP in high school students and its associated risk factors during COVID-19, a survey was conducted among 5,046 high school students in Shanghai, Qinghai, Henan and Macao during the second semester and summer vacation of the 2019–2020 academic year. The questionnaire included questions regarding demographic characteristics, the prevalence of NSP and lifestyle factors such as sedentary behavior, poor posture and electronic device usage. Univariable and multivariable logistic regression was used to analyze the possible influencing factors for neck and shoulder pain. Results A total of 4793 valid questionnaires (95.0%) were collected. The results indicated that the prevalence of NSP was 23.7% among high school students. Binary logistic regression analysis revealed that female gender (P < 0.05, OR = 1.82), grade (P < 0.05, range OR 1.40–1.51) and subject selection (P < 0.05, range OR 0.49–0.68) were risk factors for NSP in high school students. Sedentary behavior (P < 0.05, range OR 1.74–2.36), poor posture (P < 0.05, range OR 1.19–2.56), backpack weight (P < 0.05, range OR 1.17–1.88), exercise style and frequency (P < 0.05, range OR 1.18–1.31; P < 0.05, range OR 0.76–0.79, respectively), and the time spent using electronic devices (P < 0.05, range OR 1.23–1.38)had a significant correlation with NSP in high school students. Conclusions NSP is currently very common among high school students during the outbreak of COVID-19. Sedentary behavior, poor posture and other factors have a great impact on the occurrence of NSP in high school students. Education regarding healthy lifestyle choices should be advocated for to decrease NSP among high school students, such as more physical activity, changing poor postures and reducing the amount of time spent using electronic devices

Programming Nanoparticles in Multiscale: Optically Modulated Assembly and Phase Switching of Silicon Nanoparticle Array

Manipulating and tuning nanoparticles by means of optical field interactions is of key interest for nanoscience and applications in electronics and photonics. We report scalable, direct, and optically modulated writing of nanoparticle patterns (size, number, and location) of high precision using a pulsed nanosecond laser. The complex nanoparticle arrangement is modulated by the laser pulse energy and polarization with the particle size ranging from 60 to 330 nm. Furthermore, we report fast cooling-rate induced phase switching of crystalline Si nanoparticles to the amorphous state. Such phase switching has usually been observed in compound phase change materials like GeSbTe. The ensuing modification of atomic structure leads to dielectric constant switching. Based on these effects, a multiscale laser-assisted method of fabricating Mie resonator arrays is proposed. The number of Mie resonators, as well as the resonance peaks and dielectric constants of selected resonators, can be programmed. The programmable light-matter interaction serves as a mechanism to fabricate optical metasurfaces, structural color, and multidimensional optical storage devices

Programming Nanoparticles in Multiscale: Optically Modulated Assembly and Phase Switching of Silicon Nanoparticle Array

Manipulating and tuning nanoparticles by means of optical field interactions is of key interest for nanoscience and applications in electronics and photonics. We report scalable, direct, and optically modulated writing of nanoparticle patterns (size, number, and location) of high precision using a pulsed nanosecond laser. The complex nanoparticle arrangement is modulated by the laser pulse energy and polarization with the particle size ranging from 60 to 330 nm. Furthermore, we report fast cooling-rate induced phase switching of crystalline Si nanoparticles to the amorphous state. Such phase switching has usually been observed in compound phase change materials like GeSbTe. The ensuing modification of atomic structure leads to dielectric constant switching. Based on these effects, a multiscale laser-assisted method of fabricating Mie resonator arrays is proposed. The number of Mie resonators, as well as the resonance peaks and dielectric constants of selected resonators, can be programmed. The programmable light-matter interaction serves as a mechanism to fabricate optical metasurfaces, structural color, and multidimensional optical storage devices