Average Light Transmittance Research Articles

Monitoring Experiment of Melon Greenhouse’s Environment in Tropical Climate

Greenhouses in tropical climates are designed to control passively the environment, protecting plants from pest and extreme climate condition, which is increasingly important due to climate change. This research aims to monitor a melon greenhouse's environment in a tropical climate to understand light intensity, pollutants, and climate conditions. Indoor and outdoor conditions of melon greenhouse were real-time monitored by Vantage VUE model, DAVIS weather station, PM2.5 meter and noise meter. The findings examined that peak light intensities were recorded at 135,600 lux outdoors and 32,050 lux indoors at noon, with an average light transmittance of 38%. Additionally, PM2.5 levels remained stable around 26-30 µg/m³, and sound levels decreased from 60 dB in the morning to 45 dB. These pollution levels did not disturb farmer and indoor melon in winter season. However, other seasoning period needs to be monitored for long term adaptation of application and climate change mitigation. These research findings will support greenhouse design for human comfort and plant growth, considering and optimizing temperature and humidity conditions. IoTs mechanisms and devices were proposed high costly potential for monitoring sensor, networking process, comparative and reliable data collection for further next step of greenhouse integration. Lastly, upcycled transparent roof from LDPE were suggested to be continually used with minor development or plug-in devices for increasing light shade during the mid-daytime.

Polymerizable deep eutectic solvent-gels synthesized in situ under molecular engineering control exhibit excellent adhesion, freeze resistance, as well as stretching and humidity sensing capabilities

Hydrogels generally do not adhere well to different substrates and freeze at sub-zero temperatures, limiting their application. In this study, the strategy of replacing water in hydrogels with deep eutectic solvents (DES) was used to address these challenges. Specifically, choline chloride (ChCl) as hydrogen bond acceptor, acrylic acid (AA) and itaconic acid (IA) as hydrogen bond donors and polymerizable monomers constitute PDES. Afterwards, PDES-gel (PG) was obtained by adding a thermal initiator to polymerize AA and IA in PDES. PG has the following characteristics, because PG is almost water-free, it has remarkable low-temperature tolerance without any phase change at −60 °C to 20 °C. Thanks to the carboxyl groups and chloride ions contained in PG, it can form non-covalent interactions such as hydrogen bonding and ionic interactions with different substrates, so PG can adhere to various substrate surfaces. Furthermore, the breaking elongation of the novelty PG was up to ca. 960 %, tensile strength ca. 1 MPa, outstanding transparency with an average light transmittance of about 95 % in the visible-light range. Ultimately, the novel PG exhibited certain capabilities for moisture detection and deformation sensing. The new PDES-gel material developed using PDES is expected to provide new ideas for the advancement of wearable devices.

Antimicrobial and biocompatibility nature of methanol extract of Lannea coromandelica bark and edible coating film preparation for fruit preservation

This research was performed to evaluate the antimicrobial activity of methanol extract of Lannea coromandelica bark against fruit damage causing microbes such as fungi: Alternaria sp., Aspergillus sp., Botrytis sp., Cladosporium sp., Fusarium sp., Penicillium sp., Phytophthora sp., and Trichoderma sp. The bacteria: such as Chromobacter sp., Enterobacter sp., Erwinia sp., Flavobacterium sp., Lactobacillus sp., Pseudomonas sp., and Xanthomonas sp. was investigated. Furthermore, their biocompatibility nature was determined through animal (rat) model study and their fruit preserving potential was determined by edible coating preparation with chitosan and other substances. Interestingly, the extract showed dose dependent (1000 μg mL−1) activity against these microbes in the following order: Enterobacter sp. (26.4 ± 1.5) > Chromobacter sp. (25.4 ± 1.6) > Pseudomonas sp. (24.5 ± 1.3) > Flavobacterium sp. (24.3 ± 1.4) > Xanthomonas sp. (23.6 ± 1.6) > Erwinia sp. (23.6 ± 1.6) > Lactobacillus sp. (19.6 ± 1.3). Similarly, the antifungal activity was found as Penicillium sp. (32.6 ± 1.3) > Cladosporium sp. (32.6 ± 1.5) > Alternaria sp. (30.3 ± 1.2) > Aspergillus sp. (29.9 ± 1.8) > Botrytis sp. (29.8 ± 1.2) > Fusarium sp. (28.6 ± 1.5) > Trichoderma sp. (19.8 ± 1.4) > Phytophthora sp. (16.2 ± 1.1). The acute toxicity and histopathological study results revealed that the extract possesses biocompatible in nature. The illumination transmittance and active functional groups involved in interaction among test methanol extract and chitosan investigated by UV–vis and Fourier-transform infrared spectroscopy (FTIR) analyses and found average light transmittance and few vital functional groups accountable for optimistic interaction to creak edible coating. Approximately four (set I-IV) treatment sets were prepared, and it was discovered that all of the coated Citrus maxima fruit quality characteristics including total soluble solids (TSS), weight loss (%), pH of fruit pulp juice, and decay percentage were significantly (p>0.05) better than uncoated fruit.

Effect of Cu addition on the optical, electrical, and structural properties of ultrathin Ag-based oxide/metal/oxide multilayer films

Ga and Al co-doped ZnO (GAZO) were used as oxide layers to fabricate GAZO/Ag/GAZO sandwich multilayer transparent conductive films. The effects of Cu addition in the middle layer on the optical, electrical, and structural properties of multilayer films were investigated. The influences of the Ag-Cu layer and GAZO layer thickness on the optical and electrical properties of multilayer films were further studied. The experimental results show that co-sputtering Cu and adding an ultrathin Cu seed layer changed the growth pattern of Ag films. GAZO/Ag-Cu/GAZO and GAZO/Cu/Ag/GAZO multilayer films exhibit high optical transparency and high electric conductivity. The annealing treatment can enhance the optical and electrical properties of the GAZO/Ag-Cu/GAZO and GAZO/Cu/Ag/GAZO multilayer films. The lowest sheet resistance of 9.49 Ω sq−1 and maximum average light transmittance in the visible range of 95.74 % can be obtained for the GAZO/Ag-Cu/GAZO films. The corresponding figure of merit is 68.18×10−3 Ω−1. The addition of Cu in the GAZO/Ag/GAZO multilayer films led to high transmittance and low resistivity, which can be used in various photoelectronic fields to replace indium tin oxide films.

High performance zwitterionic hydrogels for ECG/EMG signals monitoring

Zwitterionic hydrogel is receiving growing interest due to their unique structure and properties. Nevertheless, overcoming the problem of weak mechanical strength and integrating multiple functions into one zwitterionic hydrogel is still a great challenge. Herein, we have designed an ion-conductive (3.0 S/m) zwitterionic hydrogel featured with many desirable properties of high strength (134 kPa), transparency (the average light transmission closes to 90%), flexibility (up to 287%), self-adhesion (187.5 N/m), low contact impedance (79 Ω) and fatigue resistance. The zwitterionic hydrogel exhibits good flexibility and fatigue resistance due to the combination of chemical cross-linking and hydrogen bonding in the structure. Additionally, it can adhere extensively to various substrate surfaces through intermolecular forces and detect small physical movements, simultaneously capturing the ECG and EMG signals of the body with precision and stability. It also demonstrates higher sensitivity (0.46) and lower RMS noise (6.83 μV) in static measurements than those of current commercial electrodes. We believe that the designed zwitterionic hydrogel has promising applications in the field of wearable biosensors.

High- and low-temperature resistant and intrinsically flame retardant poly(bisphthalazinone thioether sulfone ketone)s: Synthesis, structures and properties

High-performance polymers that are both high temperature resistant and soluble is significant for the development of high-tech fields. 4,4′-(Thiobis(4,1-phenylene))bis(phthalazin-1(2H)-one) (T-BDHPZ) monomer is synthesized by an efficient two-step method using inexpensive phenyl sulfide and phthalic anhydride as raw materials. A series of novel poly(bisphthalazinone thioether sulfone ketone)s (PBPTSKs) were synthesized via aromatic nucleophilic substitution polycondensation. The structures of PBPTSKs were characterized by NMR and FT-IR. These polymers have glass transition temperatures (Tgs) in the range of 302–328 ℃, and are soluble in N-methyl-2-pyrrolidone (NMP), pyridine (Py) and 1,1,2,2-tetrachloroethane (TECT), and partially soluble in N,N -dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), dichloromethane (DCM), trichloromethane (TCM) and pyridine. PBPTSK films were prepared by solution casting, and the average light transmittance from 400 to 800 nm of films are all over 70%. PBPTSK boards prepared by hot press molding have outstanding mechanical properties with the tensile strength and the flexural strength of 91–102 MPa and 123–135 MPa, respectively. PBPTSK boards also exhibit excellent high- and low-temperature resistance properties at 290 and −60c, respectively. Moreover, these polymers with bisphthalazinone thioether moiety have outstanding inherent flame retardancy, which pass the V-0 level of the UL-94 test. This provides opportunities to develop high-performance polymers that are both high temperature resistant and soluble, showing great prospects in frontier applications.

Optimization design of broadband absorber for high optical transparency

A broadband absorber with high optical transparency is proposed and realized using an optimization-designed method. The absorber’s reflection, lossy, and dielectric layers are considered for obtaining high optical transparency. First, to maintain microwave absorption, the artificial structures of the reflection layer are designed on the micron scale. Low square resistance and high optical transparency are achieved simultaneously. Then, considering the artificial structure fabrication process [fabricated on polyethylene terephthalate (PET)], high light transmittance polymethyl methacrylate (PMMA) was selected as the material of the dielectric layer. The permittivity of PMMA is similar to that of PET. The light reflection of layer-to-layer is reduced, and the light transmittance is improved. Finally, under the same microwave absorption band and absorption efficiency, the topology structures of the lossy layer are optimized to increase the duty ratio and the light transmittance. Through the above-mentioned design, high optical transparency and broadband microwave absorption are achieved simultaneously. The simulated and measured results prove that more than 90% of the absorption rate is obtained from 4.4 to 11.5 GHz (89.3%) and the average light transmittance reached 80%. The results verify the optimization-designed method’s effectiveness and provide technical support for transparent absorbers to be better applied to optical windows.

Effect of Thickness on Electrical and Optical Properties of ZnO:Al Films

Zinc oxide (ZnO:Al) films were prepared on a substrate of different thicknesses by sputtering at 1×10−2 mbar argon gas pressure and 200 W power. The effect of film thickness on the structural, electrical, and optical properties was investigated by X-ray diffraction (XRD), 4-point probe technique, and ultraviolet-visible spectroscopy. The XRD film crystal structure study revealed that all sample films at thicknesses of 66, 106, 150 and 193 nm, respectively, exhibited planar Hexagonal wurtzite crystal structure (002), and ZnO crystals were grown along the c-axis. The ZnO:Al film at a thickness of 66 nm had the highest strain and the smallest crystal size compared to other films. The electrical resistivity decreases with increasing film thickness. The sample at 193 nm has the lowest resistivity (1.37 Ω.m). The results showed that light transmission revealed that all sample films had high transparency in the white and near-UV region at a wavelength of 350 to 800 nm, with an average light transmittance shift of 85 - 95 %. The energy band gap increased with the film thickness of 3.49(66 nm), 3.55(106 nm), and 3.59(150 nm) eV, and decreased to 3.57 eV at 193 nm, respectively. HIGHLIGHTS The different thicknesses Zinc oxide (ZnO:Al) films were prepared by sputtering at 1×10-2 mbar argon gas pressure and 200 W power was used to study the effect of film thickness on the structural, electrical, and optical properties The electrical resistivity changing of ZnO:Al film depends on the film thickness. The electrical resistivity is reduced with increasing ZnO:Al film thickness The ZnO:Al film are highlighted by their characteristics for light transmission at the wavelengths between 350 and 800 nm, and exhibited exceptional transparency in the white and near-UV range GRAPHICAL ABSTRACT

An autonomous power temperature sensor based on window-integrated transparent PV using sustainable luminescent carbon dots.

The energy efficiency of buildings can be significantly improved through the use of renewable energy sources. Luminescent solar concentrators (LSCs) appear to be a solution for integrating photovoltaic (PV) devices into the structure of buildings (windows, for instance) to enable low-voltage devices to be powered. Here, we present transparent planar and cylindrical LSCs based on carbon dots in an aqueous solution and dispersed in organic-inorganic hybrid matrices, which present photoluminescent quantum yield values up to 82%, facilitating an effective solar photon conversion. These LSCs showed the potencial for being incorporated as building windows due to an average light transmittance of up to ∼91% and color rendering index of up to 97, with optical and power conversion efficiency values of 5.4 ± 0.1% and 0.18 ± 0.01%, respectively. In addition, the fabricated devices showed temperature sensing ability enabling the fabrication of an autonomous power mobile temperature sensor. Two independent thermometric parameters were established based on the emission and the electrical power generated by the LSC-PV system, which could both be accessed by a mobile phone, enabling mobile optical sensing through multiparametric thermal reading with relative sensitivity values up to 1.0% °C-1, making real-time mobile temperature sensing accessible to all users.

Robust and durable transparent superhydrophobic F-TNTs/TiN coating fabricated by structure tuning on surface of TiN hard coating

Robust and durable transparent superhydrophobic F-TNTs/TiN coating was innovatively prepared by surface structure tuning of TiN hard coating. In this study, TiN coating deposited by multi-arc ion plating was anodized to prepare composite structures embedded with TiO2 nanotubes, followed by treatment with 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDS) to create the F-TNTs/TiN coating. The composite coating was a layered structure with a thickness of approximately 95 nm overall. The upper two-thirds of the layer were porous layers with embedded TiO2 nanopores, while the lower layer was a dense TiN layer. The coating exhibits high transparency with an average light transmission of up to 79.6%, and excellent superhydrophobicity with static contact angle (SCA) of about 154° and sliding angle lower than 2.4°, demonstrating outstanding self-cleaning capability. The coating also had the mechanical stability of physical vapor deposition (PVD) coatings with a hardness of 21 GPa and still exhibited outstanding hydrophobicity after 20 cycles of sandpaper rubbing. In addition, the coating had favorable corrosion resistance, even after 45 days of immersion. This design provided a simple method for the preparation of robust functionalized coatings and an innovative idea for the intellectualization of PVD coatings.

Bayesian optimization of nanophotonic electromagnetic shielding with very high visible transparency.

Transparent electromagnetic interference (EMI) shielding is needed in many optoelectronic applications to protect electronic devices from surrounding radiation while allowing for high visible light transmission. However, very high transmission (over 92.5%), high EMI shielding efficiency (over 30 dB) structures have yet to be achieved in the literature. Bayesian optimization is used to optimize different nanophotonic structures for high EMI shielding efficiency (SE) and high visible light transmission (T¯ v i s ). Below 90% average visible light transmission, sandwich structures consisting of high index dielectric/silver/high index dielectric films are determined to be optimal, where they are able to achieve 43.1 dB SE and 90.0% T¯ v i s . The high index of refraction dielectric layers reduce absorption losses in the silver and can be engineered to provide for antireflection through destructive interference. However, for optimal EMI shielding with T¯ v i s above 90%, the reflection losses at the air/dielectric interfaces need to be further reduced. Optimized double sided nanocone sandwich structures are determined to be best where they can achieve 41.2 dB SE and 90.8% T¯ v i s as well as 35.6 dB SE and 95.1% T¯ v i s . K-means clustering is utilized to show the performance of characteristic near-Pareto optimal structures. Double sided nanocone structures are shown to exhibit omnidirectional visible transmission with SE = 35.6 dB and over 85% T¯ v i s at incidence angles of 70 ∘.

Temperature tolerant all-solid-state touch panel with high stretchablity, transparency and self-healing ability

Stretchable and transparent soft ionic conductors have shown great promise in the development of next-generation touch panels. However, hydrogel/organogel-based devices suffer from instability due to liquid leakage or evaporation. Solvent-free ionic elastomers (ICEs) with high transparency (average light transmission of 93 %), intrinsic conductivity (ionic conductivity of 8.8 × 10–3 S m−1), and stretchability at room temperature (strain up to 997 %) are demonstrated in this study. These ICEs are self-healable over a wide range of operating temperatures (−20 to 60 °C) in the absence of external stimulus while maintaining a highly transparent appearance. They are available as an all-solid-state human-machine interactive touch panel with self-healing ability. A surface capacitive touch system is used to sense the location touched by a finger, demonstrating its ability to sense the finger position over a broad temperature range. The functionality of the wearable touch panel is demonstrated by writing text, playing piano, playing electronic games, and controlling the movement of a toy car.

Canopy structure, photosynthesis, grain filling, and dehydration characteristics of maize varieties suitable for grain mechanical harvesting

<p id="C3">To provide technical support for the selection and popularization of corn varieties suitable for mechanized grain harvest, the canopy structure, photosynthetic characteristics, and mechanical harvesting characteristics of different types of maize varieties were compared with 24 maize varieties including Jingnongke 728 produced and widely promoted in China. The results showed that: (1) The average yield, moisture content, broken rate and impurity content at harvest of the tested varieties were 11,658.78 kg hm^-2, 24.66%, 3.90%, and 0.83%. The average yield of 18 suitable machine harvesting varieties such as Jingnongke 728 with Jing 2416 as male parent was 11,802.70 kg hm^-2, which was significantly higher by 7.69% and 4.45% than those of Zhengdan 958 and Xianyu 335, respectively. The grain moisture content at harvest was lower than 28% (average 24.61%); The average broken rate was less than 5% (average 3.42%), reaching the national standard of machine harvested grain. (2) 18 maize varieties suitable for grain mechanical harvesting such as Jingnongke 728 with Jing 2416 as male parent had small angle between stem and leaf, compact plant type, high average light transmittance and more reasonable light distribution. (3) The average net photosynthetic rate and chlorophyll content of the tested maize varieties were 34.10 μmol CO₂ m ^-2 s^-1 and 8.91 mg m². The average net photosynthetic rate of the 18 maize varieties suitable for machine harvesting with Jing 2416 as male parent was 35.21 μmol CO₂ m ^-2 s^-1, which was 19.60% and 6.73% higher than Zhengdan 958 and Xianyu 335. The average chlorophyll content was 9.87 mg m², which was 61.54% and 68.43% higher than Zhengdan 958 and Xianyu 335. (4) The average grain filling rate and dehydration rate after physiological maturity of 18 varieties with Jing 2416 as male parent were 0.83 g 100 grain^-1 d^-1 and 0.55% d^-1, respectively, which were significantly higher than those of Zhengdan 958 and Xianyu 335, showing a lower grain moisture content at harvest. (5) Correlation analysis revealed that the yield of the tested varieties was significantly positively correlated with net photosynthetic rate and grain filling rate. The net photosynthetic rate was negatively correlated with the angle between stem and leaf, and positively correlated with light transmittance and chlorophyll content. Grain moisture content at harvest was significantly positively correlated with breakage rate, impurity content and grain moisture content after physiological maturity, negatively correlated with dehydration rate after physiological maturity, and negatively correlated with grain filling rate. In conclusion, maize varieties suitable for mechanical harvesting under the condition of high planting density should have compact plant type, high canopy light transmittance, strong photosynthetic capacity, high grain filling, and dehydration rate, which could lead to achieve lower grain moisture content and higher yield.

Energy-harvesting photovoltaic transparent tandem devices using hydrogenated amorphous and microcrystalline silicon absorber layers for window applications

Transparent photovoltaic (TPV) tandem devices were prepared via plasma-enhanced chemical vapor deposition, using hydrogenated amorphous (a-Si:H) and microcrystalline (mc-Si:H) absorber layers that were sandwiched by transparent conducting oxide (TCO) electrodes. The high-performance TPV tandem devices were designed by controlling the film thickness of the mc-Si:H absorbers. For the TPV tandem devices with 300-nm-thick a-Si:H top cells, increasing the absorber thickness (tbottom) of mc-Si:H bottom cells from 1.0 to 2.1 μm induced an increase in power conversion efficiencies (PCEs) from 6.5% to 8.3% with a minor decrease in the average light transmittance from 16.6% to 14.6% at the 500–800 nm wavelengths. The TPV tandem devices exhibited JSC gains from 4.3 mA cm−2 (tbottom = 1.0 μm) to 0.5 mA cm−2 (tbottom = 2.3 μm) under bifacial illumination (front: 100 mW cm−2 and rear: 30 mW cm−2). This further resulted in additional PCE gains from 2.8% (tbottom = 1.0 μm) to 0.4% (tbottom = 2.3 μm), in comparison to the corresponding samples under front illumination only. The TPV tandem devices demonstrated excellent PV performance even at low-light illumination intensities (∼21 mW cm−2) in comparison to those at standard illumination light intensity (100 mW cm−2), while maintaining PCE values as high as 80%.

Application of renewable materials in energy saving of new building solar greenhouse

This paper studies the application of renewable materials in the energy saving of new building solar greenhouse, and analyzes the influence of different building materials on the energy saving of solar greenhouse, it can adjust the angle of the sunlight greenhouse roof manually to improve the solar radiation into the room and adjust the fan system manually to increase the heat storage of the back wall. The test greenhouse located in a modern production base of a city was measured, and the test data under different weather conditions in winter of 2020 were selected to analyze the characteristics of temperature and light data indexes in the renewable material solar greenhouse and common material solar greenhouse, and the active lighting mechanism and active heat storage mechanism of the renewable material new building solar greenhouse were theoretically studied. The results show that the average light transmittance and indoor illumination of the solar greenhouse with recycled materials are increased compared with that of ordinary materials under different weather conditions in winter. In winter solstice, cloudy days and sunny days, the light transmittance of active daylighting and heat storage solar greenhouse was 61.17%, 58.26%, and 70.81%, respectively, which was 7.87%, 5.88%, and 11.45% higher than that of ordinary energy-saving solar greenhouse, and the corresponding indoor illumination was 15.42%, 11.73%, and 21.28% higher than that of ordinary energy-saving solar green?house. In terms of temperature, under different weather conditions in winter, the indoor temperature and ground temperature of the solar greenhouse with active daylighting and heat storage are significantly higher than those of the control material energy-saving solar greenhouse. The temperature difference between indoor and outdoor is above 27?C.

Simulation and Experimental Study of Light and Thermal Environment of Photovoltaic Greenhouse in Tropical Area Based on Design Builder

In order to study the adaptability of photovoltaic greenhouses to climate in tropical areas, a photovoltaic greenhouse model (photovoltaic panel coverage rate: 76.9%) was built in this study according to a 1:1 proportion. The distribution law of the indoor illuminance, temperature, and humidity were studied simultaneously in the photovoltaic greenhouse by actual measurements and simulation. The filed data are shown as follows: (1) Illuminance: in limited rain winter, the average illuminance and light transmittance were 7.02 kLux and 25.77%, respectively (10:00–16:00); but in different weather conditions during summer, the average illuminance and light transmittance were 15.47 kLux and 32.35%, respectively (9:00–16:00). (2) Temperature and humidity: the indoor temperatures of the greenhouse were between 22.1 and 29.3 °C in limited rain winter, with a relative small temperature difference between indoor and outdoor environments; the relative humidity values were between 69% and 97%; but in summer, the temperatures at all indoor test site were higher than outdoor sites, with an average temperature difference of 2.7 °C and relative humidity values between 46% and 94%. According to the simulation by Design Builder, the average light transmittances were 33.09% in winter and 37.54% in summer, the temperature difference between winter and summer was less than 1 °C, and the relative humidity decreased with the increase of temperature, which basically coincided with the filed data. The results of the analysis showed that the illuminance, temperature and humidity of the photovoltaic greenhouse can satisfy the production requirements of shade-enduring and neutral crops. At the same time, by comparing the illumination, temperature and humidity of the photovoltaic greenhouse with that of an ordinary greenhouse, the former had good adaptability to climate in tropical areas, which can achieve the goal of photovoltaic generation and agricultural production synchronously.

Selectively absorbing small-molecule solar cells for self-powered electrochromic windows

Dynamic control of solar transmission by photovoltaic-powered electrochromic smart windows is an up-and-coming approach towards the reduction of energy consumption in buildings. Selectively-absorbing transparent organic solar cells are capable of exhibiting excellent visible-light transparency as well as respectable power conversion efficiencies. This work presents three different transparent small-molecule solar cells (TSCs) with an area of 2.52 cm2, two of which are UV-absorbing and one of which absorbs in the NIR, each in combination with an organic electrochromic device (EC). The NIR-absorbing TSC uses a BDP-OMe:C60 combination, and has a power conversion efficiency of 4% with an average visible light transmission (AVT) of 40%. The two UV-harvesting systems, α-6T/B4PYMPM and NPB:B4PYMPM, each have an AVT of 50–65%, as well as high open-circuit voltages of 1.5–2.0 V. We demonstrate that these photogenerated voltages are sufficient to power a fluoran dye-based organic EC, which has excellent optical properties: its color ranges from highly transparent to deep black, and its on/off contrast ratio is higher than 80% in the range between 390 nm and 640 nm. Self-powered smart windows made by the combination of TSCs and ECs provide a way to significantly reduce energy consumption from air conditioning and lighting, towards zero-energy buildings.

Effect of Sputtering Power on the Optical and Electrical Properties of ITO Films on a Flexible Fluorphlogopite Substrate

AbstractIn this study, magnetron sputtering is implemented to adjust the sputtering power from 156 to 306 W at room temperature, and thin film samples of indium tin oxide (ITO) on a flexible fluorphlogopite substrate are taken. With the increase in power, the resistivity of the film first decreases and then increases. The resistivity is at least 1.51 × 10–3 Ω cm at 276 W, and the highest resistivity is 2.93 × 10–2 Ω cm at 156 W. The average light transmittance of the film (400–800 nm) decreases with the increase in power within the range of 156–276 W, The highest average transmittance is 92.6% at 156 W. The quality factor of the film first rises and then decreases as the power increases, it is as high as 4.47 × 10–3 Ω–1sq at 276 W. All the AFMs show that the roughness of the sample does not significantly change with power. The SEM picture shows that as the power increases from 156 to 276 W, the grain size increases slightly. All samples are bent 1200 times around a steel cylinder, and the sheet resistance does not change more than 5%.

Characterization of a Disjunct Population of Eastern Hemlock (Tsuga canadensis) and Surrounding Plant Communities in the North Carolina Piedmont after 65 Years of Forest Change

Hemlock Bluffs Nature Preserve is a 57-ha preserve in the piedmont of North Carolina. A small disjunct Tsuga canadensis (Eastern Hemlock) population exists in the preserve, primarily within a microclimate on a north-facing bluff. A study published in 1956 included a 1952–1953 inventory of the hemlock population as well as records of the local flora and climate. We re-inventoried the Eastern Hemlock population, conducted a new floristic survey, and recorded new climate data in the preserve in 2018–2019. Our new data reveal a notable change in both the Eastern Hemlock population and preserve-wide stand structure. Only 2% average light transmittance through the canopy was recorded in the preserve in the 2019 growing season, compared to 11% in the 1953 growing season (P = 0.02). At least 7 plant taxa underwent notable shifts in distribution, mostly moving down-slope on the bluff face. Average ambient air temperatures on the bluff were 1.62 °C higher in 2018–2019 than in 1952–1953. Canopy closure, inbreeding depression, increased temperatures, erosion, and browsing by Odocoileus virginianus (White-tailed Deer) all likely contribute to low Eastern Hemlock seed germination and high seedling mortality within the preserve. These factors may also partially account for observed shifts in floristic distribution. In addition to mortality caused by Adelges tsugae (Hemlock Woolly Adelgid), these environmental changes endanger the future viability of this Eastern Hemlock population.

Weighted Polynomial-Based Secret Image Sharing Scheme with Lossless Recovery

In some particular scenes, the shadows need to be given different weights to represent the participants’ status or importance. And during the reconstruction, participants with different weights obtain various quality reconstructed images. However, the existing schemes based on visual secret sharing (VSS) and the Chinese remainder theorem (CRT) have some disadvantages. In this paper, we propose a weighted polynomial-based SIS scheme in the field of GF (257). We use k , k threshold polynomial-based secret image sharing (SIS) to generate k shares and assign them corresponding weights. Then, the remaining n − k shares are randomly filled with invalid value 0 or 255. When the threshold is satisfied, the number and weight of share can affect the reconstructed image’s quality. Our proposed scheme has the property of lossless recovery. And the average light transmission of shares in our scheme is identical. Experiments and theoretical analysis show that the proposed scheme is practical and feasible. Besides, the quality of the reconstructed image is consistent with the theoretical derivation.