Sunlight Environments Research Articles

Study on the elderly's perception of microclimate and activity time in residential communities

The significance of outdoor environment is increasingly being recognized, particularly for the elderly. Using residential community green spaces is beneficial for their physical and mental health. This study aims to explore the thermal comfort, usage patterns, and microclimate preferences of the elderly through environmental factors and demographic information. Field measurements and questionnaire surveys were conducted across 19 residential communities in 3 cities within Building Climate Zone II in China during the summer. Descriptive and logistic regression analyses were employed to examine various factors related to the elderly's thermal comfort, duration of activity, and microclimate preferences. The study revealed that elderly residents in communities of various types experience different thermal comfort levels and have different durations of activity and preferences for microclimates. In addition, elderly adults with longer activity durations are less likely to prefer windless, drier, and more sunlight environments in the summer. Built environmental factors, personal factors, and features of public facilities were also found to have an impact on thermal comfort and activity. These empirical findings provide urban planners with insights to better cater to the needs of the elderly in residential area design, emphasizing the importance of considering thermal comfort and microclimate preferences in the planning process.

P‐70: A Novel Peak Luminance Correction Method Based on Global IR Drop Compensation System on AMOLED

In the past year, AMOLED have been widely used in smartphones, laptops, and vehicles. Local excitation luminance is one of the important parameters to measure AMOLED quality. This feature is of great significance for realization of HDR video and getting better visual experience in sunlight environment. Due to IR drop effect in the local display, the performance of peak luminance is often skewed by luminance, chrominance, and gamma curves. The solution is adding a set of Gamma curve debugging at peak luminance of local display, which results in longer take time (TT) and greater aging pressure at high luminance. In this paper, we propose a novel peak luminance correction method based on Global IR (GIR) voltage drop compensation system. In the compensation system, GIR compensation Look‐Up Tables (LUT) is used to accurately tune the luminance, chrominance, and gamma curves that correspond to the local excitation luminance.

Facile Preparation of Impalement Resistant, Mechanically Robust and Weather Resistant Photothermal Superhydrophobic Coatings for Anti-/De-icing.

Photothermal superhydrophobic coatings hold great promise in addressing the limitations of conventional superhydrophobic anti-icing coatings. However, developing such coatings with excellent impalement resistance, mechanical robustness and weather resistance remains a significant challenge. Here, we report facile preparation of robust photothermal superhydrophobic coatings with all the above advantages. The coatings were prepared by spraying a dispersion consisting of fluorinated silica nanoparticles, a silicone-modified polyester adhesive and photothermal carbon black nanoparticles onto Al alloy plates followed by thermal curing. Thermal curing caused migration of perfluorodecyl polysiloxane from within the coatings to the surface, effectively maintaining a low surface energy despite the presence of the adhesive. Therefore, combined with the hierarchical micro-/nanostructure, dense yet rough nanostructure, adhesion of the adhesive and chemically inert components, the coatings exhibited remarkable superhydrophobicity, impalement resistance, mechanical robustness and weather resistance. Furthermore, the coatings demonstrated excellent photothermal effect even in the -10 °C, 80 % relative humidity and weak sunlight (0.2 sun) environment. Consequently, the coatings showed excellent passive anti-icing and active de-icing performance. Moreover, the coatings have good generalizability and scalability. We are confident that this study will accelerate the practical implementation of photothermal superhydrophobic coatings.

Gallium oxide cantilevered thin film-based solar-blind photodetector and its arc detection applications

The performance of gallium oxide (Ga<sub>2</sub>O<sub>3</sub>) thin film detector based on metal-semiconductor-metal (MSM) is highly dependent on the uniformity of the Ga<sub>2</sub>O<sub>3</sub> thin film, and the manufacturing process is quite sophisticated, which poses a challenge for the scale-up and mass production of thin film photodetectors. In this work, an MSM Ga<sub>2</sub>O<sub>3</sub> thin film solar-blind photodetector with five-finger interdigital electrodes is fabricated by physically depositing Ga<sub>2</sub>O<sub>3</sub> thin film on the surface of a mass-produced cantilevered thin film chip. Through the microelectromechanical system (MEMS) process, the cantilever electrode structure is prepared, which protects the internal circuit and the integrity of the thin film. The Ga<sub>2</sub>O<sub>3</sub> thin film treated by argon plasma at a low temperature is amorphous, but the photodetector still possesses considerable ultraviolet detection performance. At a bias voltage of 18 V, it approaches the detection performance of crystalline Ga<sub>2</sub>O<sub>3</sub> thin film, with a detectivity of 7.9×10<sup>10</sup> Jones, an external quantum efficiency of 1779%, rise time and decay time of 1.22 s and 0.24 s, respectively. Moreover, a system of arc detection is built in outdoor environments. Without any optical focusing system, this photodetector achieves sensitive detection of pulsed arc in an outdoor sunlight environments. For pulsed arcs with an output voltage of 100 kV, the photodetector is capable of sensitive detection at a distance of 25 cm. Besides, the maximum detection distance of 155 cm indicates that the photodetector will have a favorable potential application value in the field of solar-blind detection. This work develops a sensitive functional thin film deposition technology based on the cantilever electrode structure fabricated by the MEMS process, which avoids the influence of the large-area uniformity of the functional thin film on the etching circuit. It provides a new technical approach and process route for preparing MSM photodetectors.

Phenotypic and transcriptional features of Araliaceae species under distinct light environments

AbstractElucidating how plant species respond to variable light conditions is essential to understanding the ecological adaptation to heterogeneous environments. Plant performance and gene regulatory network underpinning the adaptation have been well documented in heliophytic species. However, it remains largely unclear how the sciophytic plants respond to distinct light conditions. We measured phenotypic and transcriptomic features of four sciophytic (Fatsia japonica, Metapanax delavayi, Heptapleurum arboricola, and Heptapleurum delavayi) and one heliophytic woody species (Tetrapanax papyrifer) of the Araliaceae family under distinct light conditions. Our phenotypic comparisons demonstrate that the four sciophytic species maintain similar photosynthesis efficiency between high light and low light conditions. However, a significantly decreased photosynthesis rate was observed under the low light conditions of the heliophytic species compared with the high light conditions. In addition, our leaf anatomical analyses revealed that, while all five species showed different anatomical structures under distinct light conditions, the sciophytic species possessed a lower degree of phenotypic plasticity relative to the heliophytic species. Further comparisons of the transcriptome profiling showed that differentially expressed genes identified in the five species were functionally related to photosynthesis, secondary metabolites, and other basic metabolisms. In particular, differential regulation of the photosynthesis‐related and photomorphogenesis‐related genes were potentially correlated with the phenotypic responses to the distinct light conditions of the five species. Our study provides evolutionary and ecological perspectives on how the heliophytic and sciophytic woody species respond to shade and sunlight environments.

All-weather real-time ore detection method based on near-infrared structured light and zero-crossing points characteristics

To address the low efficiency of ore detection methods caused by the complex lighting environment of mining sites, an all-weather real-time ore detection method based on near-infrared structured light and zero-crossing points characteristics was proposed. Firstly, an image acquisition method based on the infrared–visible radiation detection model (IVRDM) is proposed to avoid structured light imaging being disturbed by a strong sunlight environment; Then, the centerline of the light bar is extracted quickly and accurately based on the zero-crossing point characteristics; Finally, the light bar neighborhood splicing detection method was proposed to realize the real-time detection and 3D measurement of the target ore. The experimental results show that the proposed method can effectively resist strong sunlight interference and faster detection speed, the average extraction time of light bar centerline per frame is below 1.8 ms, and the error rate of ore size detection is <5 %.

High-Efficient Anti-Icing/Deicing Method Based on Graphene Foams.

Anti-icing/deicing has always been a focal issue in modern industries. A novel anti-icing/deicing material based on graphene foams (GF) is prepared in this paper, which integrates multiple functions, including electrothermal conversion, photothermal conversion, and superhydrophobicity. The GF sheet is used as a bottom layer bonded on the protected substrate, which is covered by a polymeric composite coating filled with TiN and SiO2 nanoparticles. Electric heating and light heating experiments are performed to study the anti-icing/deicing performances of such a GF-based material. It is found that, under the unique action of electric fields, a voltage of only 1 V is needed to increase the surface temperature from minus tens of degrees to the one above zero within 400 s, which is much lower than their previous counterparts of more than 10 V to achieve the same unfreezing effect. A slight increase of the applied voltage to 1.5 V can even result in a remarkable increase of the surface temperature from room temperature to more than 150 °C within 200 s, in contrast to existing electric heating techniques to attain peak temperatures of about 100 °C at the expense of tens of volts. Such performances enable the GF-based material to achieve an outstanding electrothermal energy conversion rate of more than 90%. Furthermore, with the help of sunlight illumination in addition to the electric power, not only can the critical voltage to prevent icing be reduced but also a much more rapid and adequate removal of ice or frost from the surface can be realized compared with the deicing/defrosting performance under either electric or light field alone. All of these results demonstrate the obvious advantages of the present method in superior energy utilization efficiency and universal applicability to dark and sunlight environments, which should be particularly useful for at-all-cost protection of key components in industrial equipment from icing.

Synergistic effect of bimetallic cobalt-based sulfide enhances the performance of ZnSe photocatalytic hydrogen evolution by Z-scheme

In this work, ZnSe/ZnCo2S4 (ZCS) composites were synthesized by simple hydrothermal method and Z-scheme heterojunctions were formed. Under the simulated sunlight environment, The results show that the hydrogen production efficiency of 70 wt% ZnSe/ZCS composites was as high as 3402.4 μmol·g−1·h−1, which is 4.37 and 94.44 times that of ZnSe and ZCS monomers, respectively, and the apparent quantum efficiency (AQY) reaches 10.5%. Among them, the Z-scheme heterojunction improves the redox ability of the material, which is more conducive to charge separation, and ZCS also promotes absorption of visible light of ZnSe/ZCS. In addition, the Z-scheme heterojunction structure and material stability were verified by XPS, ESR.This work provides a new way to improve ZnSe in the field of photocatalytic hydrogen evolution.

Compact remote Raman system and its applications under strong sunlight research

Raman signal with a high signal-to-noise ratio (SNR) under a strong sunlight environment of 30000∼60000 Lux is very hard to obtain. A compact remote Raman spectrometer (CRS) has been developed for the purpose of detecting diverse types of lunar and earth minerals. The system comprises a spectrometer that is equipped with an ICCD detector, a 30 mm entry pupil diameter beam expander, and a 532 nm Nd: YAG Q-switched laser serving as the source of Raman scattering. The implementation of synchronous trigger and gating technology effectively overcomes the impact of strong sunlight. We obtained Raman spectra using a shorter integration time than in previous studies. The experimental results demonstrate that the detection of remote Raman spectroscopy under intense sunlight conditions facilitates the identification of silicates that have been discovered on the moon.

Fabricating a photochromic benzonitrile Schiff base into a low-cost reusable paper-based wearable sensor for naked-eye dosimetry of UV radiations

We report in this study a photochromic benzonitrile Schiff base, (E)-4-((2-hydroxy-4-methoxybenzylidene)amino)benzonitrile (HMBAB). The molecular design, synthesis, aggregation-induced emission (AIE) as well as the quantum chemical calculations were outlined. In particular, HMBAB would undergo a reversible tautomerism in response to UV exposure, exhibiting remarkable changes in both absorption and emission: the compound shows yellow color and green-yellow luminescence; after UV exposure, the changes into orange-red while the luminescence is dramatically quenched, accompanied by a large bathochromic-shift. In addition, the photochromic state can be fully recovered via thermal treatment. Such reversible dual-channel photochromism was investigated using UV–vis reflectance spectroscopy and colorimeter, wherein a gradient change with time and a high fatigue resistance in cycle use was recorded. The photochromism is quantified by well-established RGB and Lab color space, in which the color change can be accurately analyzed by the chromatic aberration (ΔE*Lab). Sensitivity test gives a two-stage linear relation between ΔE*Lab and UV intensity, by which a limit of detection (LOD) as low as 67 μW/cm2 is obtained. HMBAB was further fabricated into a paper-based wearable sensor, capable of being integrated into a chest card or a bracelet. It exhibits various degrees of color change in different sunlight environments, which can be readily observed by naked eyes, providing an early warning for high-dose UV radiations.

A new acridine-based photosensitizer with ultra-low light requirement efficiently inactivates carbapenem-resistant Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus and degrades their antibiotic resistance genes

The spread of antibiotic resistant pathogens and antibiotic resistance genes (ARGs) in the environment poses a serious threat to public health. However, existing methods are difficult to effectively remove antibiotic resistant pathogens and ARGs from the environment. In this study, we synthesized a new acridine-based photosensitizer, 2,7-dibromo-9-mesityl-10-methylacridinium perchlorate (YM-3), by the heavy atom effect, which could photodynamically inactivate antibiotic resistant pathogens and reduce ARGs by generating singlet oxygen (1O2) in an aqueous environment. The 1O2 yield of YM-3 was 4.9 times that of its modified precursor. YM-3 could reduce the culturable number and even the viable counts of methicillin-resistant Staphylococcus aureus and carbapenem-resistant Acinetobacter baumannii to 0 (inactivation rate > 99.99999%) after 2 and 8 h of low-intensity blue light (15 W/m2) irradiation, respectively. After 20 h of light exposure, the copy numbers of ARGs in both bacteria were reduced by 5.80 and 4.48 log, respectively, which might indicate that ARGs had been degraded. In addition, YM-3 still had an efficient bactericidal effect after five inactivation cycle. These characteristics of ultra-low light intensity requirement and efficient bactericidal ability make YM-3 have good application prospects for disinfection in indoor and sunlight environment.

Ambient light stimulation enabling intense and long-lasting ultraviolet-C persistent luminescence from Pr3+-doped YBO3 in bright environments

Intense and long-lasting UVC persistent luminescence can be realized in the YBO3:Pr3+ phosphor through the continuous photostimulation of ambient light in a bright indoor lighting or an outdoor sunlight environment.

An Extended Polarization Sensor Model Considering the Influence of Obliquely Incident Direct Sunlight

The polarization sensor model plays a key role in bioinspired polarization navigation. Existing models consider the linearly polarized light and vertically incident unpolarized light. The performance of the polarization sensor, however, will be degraded due to the effect of obliquely incident direct sunlight. To account for the influence of obliquely incident direct sunlight and improve the conventional model, we established an extended polarization sensor model. In the proposed model, the transmitted intensity of direct sunlight obliquely passing through the polarizer is analyzed, and the influence of obliquely incident direct sunlight on the polarization sensor is characterized. Then, the extended polarization model is established considering the linearly polarized light and vertically incident unpolarized light, as well as the obliquely incident direct sunlight. Based on the proposed model, the secant Levenberg–Marquardt (LM) least-squares algorithm is used to estimate the polarization parameters of interest, such as Degree of Polarization (DoP) and Angle of Polarization (AoP). Finally, the effectiveness of the proposed polarization sensor model is verified via simulation, indoor, and outdoor experiments. The results show that the root mean square of AoP error can be narrowed to 0.67° even under the obliquely incident direct sunlight environment.

Tailoring and properties of a novel solar energy-triggered regenerative bionic fiber adsorbent for CO2 capture

Using renewable solar energy sources instead of heat energy to desorb CO2 from adsorbents is a promising strategy for reducing the energy consumption of adsorbent regeneration. However, the photothermal temperature of adsorbents with high CO2 adsorption capacity cannot desorb CO2 efficiently in a real sunlight environment. Here, a novel solar energy-triggered regenerative bionic fiber adsorbent for CO2 capture was designed via bionic electrostatic and chemical cross-linking assembly of cellulose nanofibers, thermosensitive polymer poly(N-isopropylacrylamide), nano-graphene oxide and polyethyleneimine. Excellent photothermal transformation characteristics, thermosensitivity and high density of amino adsorption sites were synchronously endowed onto cellulose nanofibers with hydroxyl groups. The thermosensitivity and hydroxyl synergy of the adsorbent enables it an ultralow regeneration temperature (60 °C) by preventing the formation of refractory urea. Interestingly, the adsorbent possesses a high CO2 adsorption capacity (6.52 mmol/g) and can be efficiently regenerated by using renewable solar energy, indicating that it is a promising strategy for greatly reducing the energy consumption for adsorbent regeneration.

Highly Sunlight Reflective and Infrared Semi-Transparent Nanomesh Textiles.

Radiative cooling in textiles is one of the important factors enabling cooling of the human body for thermal comfort. In particular, under an intense sunlight environment such as that experienced with outdoor exercise and sports activities, high near-infrared (NIR) reflectance to block sunlight energy influx along with high IR transmittance in textiles for substantial thermal emission from the human body would be highly desirable. This investigation demonstrates that a nanoscale geometric control of textile structure alone, instead of complicated introduction of specialty polymer materials and composites, can enable such desirable NIR and IR optical properties in textiles. A diameter-dependent Mie scattering event in fibers and associated optical and thermal behavior were simulated in relation to a nonwoven, nanomesh textile. As an example, a nanomesh structure made of PVDF (polyvinylidene fluoride) electrospun fibers with ∼600 nm average diameter was examined, which exhibited a significant radiative cooling performance with over 90% solar and NIR reflectance to profoundly block the sunlight energy influx as well as ∼50% IR transmittance for human body radiative heat dissipation. An extraordinary cooling effect, as much as 12 °C, was obtained on a simulated skin compared to the normal textile fabric materials. Such a powerful radiative cooling performance together with IR transmitting capability by the nanomesh textile offers a way to efficiently manage sunlight radiation energy to make persons, devices, and transport vehicles cooler and help to save energy in an outdoor sunlight environment as well as indoor conditions.

Analysis of Height-to-Width Ratio of Commercial Streets with Arcades Based on Sunshine Hours and Street Orientation

By extracting and simplifying the characteristics of commercial streets with arcades (Qilou) in Nanning, the tissue map of Qilou streets which reflects the urban morphology, including the road network form, block scale, building scale and other characteristics in a hot and humid area is obtained. In addition, the sunshine simulation is performed by using sunshine design software in an environment comprising streets with arcades to simulate street sunlight environments under various conditions. The relationship among street height-to-width ratio, sunshine hours, and street orientation angle is achieved by nonlinear fitting analysis. Then, a model is established to adjust the street height-to-width ratio based on sunshine requirement and street orientation. The finding indicated that when the street is north–south, it is suggested that the street height-to-width ratio is 0.95–1.13 to reduce sunshine hours effectively, and when the street is east–west, it is proposed that one side of the street should have a recessed space to improve the thermal conditions. The results of this study can serve as the specific guidelines that can be adopted in the redesign and reformation of commercial streets with arcades to achieve thermal comfort of Qilou streets in hot and humid areas.

Sunshine environment in different forms of communities in Guiyang, China.

In this study, six different types of residential areas in Guiyang were selected as the research objects, including high-rise high-density, high-rise low-density, middle-rise high-density, middle-rise low-density, low-rise high-density and low-rise low-density. The indices of sunshine compliance rate and the building's sunshine hour ratio were constructed to compare and analyze sunshine environment across those six different residential areas. The factors influencing sunshine environment in different residential areas were studied. The results showed that the average sunshine compliance rates of the six types of residential areas were 36.9%, 61.9%, 20.6%, 69.6%, 26.5% and 45.0%, respectively. The average sunshine compliance rate of low-density residential areas was 2.25 times higher than that of high-density residential areas within the same type, among which the sunshine environment of low-density residential areas was better. The sunshine environment of different types of low-density residential areas was different. The sunshine hours for high-rise low-density and middle-rise low-density forms were concentrated in 5-6 hours, while the building's sunshine hour ratio was 0.24 and 0.32, respectively. The sunshine hours for low-rise low-density forms were mainly 6-7 hours, with a building's sunshine hour ratio of 0.28. Compared with other types of residential areas, the low-rise low-density type of sunlight environment was the best. The plot ratio was significantly positively correlated with the building's sunlight ratio of 0-1 h sunlight hours in the residential area.

The role of microsite sunlight environment on growth, architecture, and resource allocation in dominant Acacia tree seedlings, in Serengeti, East Africa

Seedling establishment is a critical life history stage for savanna tree recruitment due to variability in resource availability. While tree–grass competition for water is recognized as an important driver of tree seedling mortality, the importance of sunlight exposure on tree seedling performance has received little attention in savanna ecosystems despite variable seedling light environments caused by heterogeneity in biomass of the grass canopy. We studied the seasonal sunlight micro-environment for two dominant East African tree species (Acacia = Vachellia) robusta (Burch) and A. tortilis (Forssk) under natural field conditions. In the Serengeti National Park, Tanzania, A. robusta trees occur in tall grasslands of the north (shady) and A. tortilis in the southern short grasslands (less shaded). We also designed a greenhouse experiment to quantify sunlight effects on seedling growth, architecture, and resource allocation traits. In the field, A. robusta seedlings were associated with lower understorey sunlight during the wet season compared to A. tortilis, with this trend switching during the dry season. In the greenhouse experiments, under low sunlight (25% radiation), A. robusta gained height faster than A. tortilis and self-shading among canopy leaves was evident in A. tortilis but not A. robusta. Biomass allocation to leaves, stems, and roots differed between species under different light environments suggesting phenotypic plasticity in response to variable light availability. Our study suggests that microsite light variability should be incorporated in models of the spatial and temporal variability of savanna tree recruitment.

Finite Element Analysis of Thermal Stress of GIS Shell in Sunlight Environment

In order to study the thermal stress of the GIS shell under normal internal pressure in the sunshine environment, First, the 24-hour temperature field on the surface of the GIS shell of a substation is detected for and the temperature change curve is plotted. Then the ANSYS software is used to carry out finite element stress analysis including temperature field on GIS shell. During the analysis, select the highest temperature and lowest temperature periods, fit the temperature distribution curve of the cross section of the shell varying with the angle under the two conditions, and apply the corresponding temperature load of the two conditions to obtain the stress distribution and stress amplitude distribution. The results show that under normal sunlight environment, the stress of the shell without stress concentration is less than 30Mpa, and the stress variation value caused by diurnal temperature difference in most areas of the shell is within 5MPa, and it can reach about 10Mpa at the top where the stress concentration occurs. This study analyzes the stress distribution and fluctuation range of the GIS shell under the solar radiation, which provides important data support for the safety evaluation of the GIS shell.

Research on Energy Saving greenhouse based on Sunlight Environment

This paper combs the current research on the energy-saving greenhouse in a daylight environment. The application and research progress of thermal insulation and energy-saving technology in the solar greenhouse in China are introduced from the aspects of location, type, orientation, front roof, rear roof, wall, multi-layer cover in a greenhouse, cold prevention ditch, cheap energy, utilization and cultivation of energy-saving equipment, operation, and management. Finally, some suggestions are given for the future research of energy-saving greenhouse in the solar environment, to make a certain contribution to the research of energy-saving greenhouse in the solar environment.