Increase In Radiation Intensity Research Articles

The Effect of Radiation Intensity on the Performance of Direct-Expansion Solar PVT Heat Pump Systems

The objective of this study was to investigate the impact of solar radiation intensity on the performance of direct-expansion solar PVT heat pump systems. To this end, an experimental setup was constructed for direct-expansion photovoltaic (PVT) solar heat pump water heating systems and photovoltaic (PV) power generation systems. The system performance and main parameters were analyzed and discussed under different solar radiation intensities. The winter experiments in southern China revealed that the exhaust temperature of the heat pump unit varied considerably under clear conditions, while the back temperature remained stable, fluctuating between approximately −13.5 °C and 24 °C. In contrast, the power generation of PVT panels increased with the increase in radiation intensity, from 78.33 W to 122.68 W, for an increase of 56.6%. Furthermore, the total electricity generation of the PVT panels was higher than that of PV panels, with an increase of 8.7–8.3%. Nevertheless, discrepancies between experimental and theoretical data were observed, particularly under overcast conditions, where the back panel temperature error was pronounced. Additionally, the system exhibited enhanced stability at elevated temperatures in comparable environments, accompanied by an improvement in the system’s coefficient of performance (COP) by 5.67%.

Study on combustion characteristics of glass fiber/phenolic resin composites

In order to study the combustion characteristics of glass fiber/phenolic resin composites, a conical calorimeter was used to explore the combustion characteristics of glass fiber/phenolic resin composites in an aircraft frame under different thermal radiation intensities, and the fire hazard of the materials was evaluated by evaluation index, and the limiting oxygen index at different temperatures was explored by combining the high temperature oxygen index meter. The test results show that when the ambient temperature increases from 20 °C to 220 °C, the limiting oxygen index first increases from 86.6 % to 93.7 %, and then decreases to 84.4 %. The oxygen consumption and CO2 release increase with the increase of thermal radiation intensity during combustion, and the release of CO decreases with the increase of thermal radiation. The heat release rate curve of the test material has only 1 enhancement peak. The heat radiation intensity increased from 50 kW/m2 to 70 kW/m2, and the peak heat release rate of the test material combustion increased from 64.7 kW/m2 to 100.7 kW/m2. The rate of mass loss of materials accelerates with the increase of thermal radiation intensity; As the intensity of thermal radiation increases, the fire hazard of the material increases.

Study of Photovoltaic Double-Skin Façade Windows in Passenger Ships

The ship-mounted photovoltaic (PV) system was an approach to solve the problem of pollution caused by excessive energy consumption during navigation. However, PV systems used on ships faced problems such as small installation areas, which prevented PV power generation from being utilized on a large scale. This article proposes a space-saving photovoltaic double-skin façade (PV-DSF) window system, which could be used in conjunction with ships to address the insufficient ship-mounted photovoltaics. In this paper, we propose a space-saving photovoltaic double-skinned façade (PV-DSF) window system that could be used in conjunction with a ship to solve the problem of insufficient space for onboard photovoltaics. According to the working principle of the system, we established a mathematical model corresponding to the actual heat transfer process and, at the same time built up a corresponding experimental test rig for thermoelectric performance measurement, and verified the accuracy of the proposed mathematical model based on the experimental results. Finally, the effect of different parameters on the performance of the system and the energy performance of the system on board the ship was discussed using a mathematical model. The simulation data showed that the increase of solar radiation intensity, wind speed, and PV coverage had a positive effect on the system’s power generation, while the ambient temperature had a negative effect. The system, in combination with a passenger ship, was able to provide 53.2 kWh of annual electricity generation and reduced CO2 emissions by 17 kg.

Study on performance of direct-expansion heat pump water heater integrated uninsulated micro-channel PV/T solar collector

In this paper, a direct-expansion heat pump water heater system integrated uninsulated micro-channel PV/T solar collector (UMC-PVT-SC) is proposed. This system can realize storage for both thermal energy and electricity, ensuring the supply of domestic hot water. The theoretical models of micro-channel PV/T solar collector, hot water storage tank, compressor and electronic expansion valve are established to investigate the performance of the micro-channel PV/T heat pump water heater system. R134a is used as refrigerant. The system performance is numerically simulated using MATLAB for different solar radiation intensity, ambient temperature and wind speed. The results show that solar radiation intensity has the largest influence on the system performance, followed by ambient temperature and wind speed. The coefficient of performance of the heat pump (COPHP) and the overall coefficient of performance (COPpvt) of the integrated system increase while the required operating time reduces, as solar radiation intensity and ambient temperature increase. The uninsulated micro-channel PV/T solar collector (evaporator) can absorb thermal energy from both ambient air and solar radiation and therefore achieve high COPHP, electric efficiency and COPpvt. Even under cold weather conditions, the proposed solar collector and heat pump heater demonstrate high efficiencies, heating and power generation capacities. When ambient temperature is −18.6 °C and solar irradiance is 322 W/m2, the collector efficiency and electric efficiency of UMC-PVT-SC are still at 0.718 and 0.244, respectively, and the COPHP and COPpvt of the heat pump heater are 3.5, 5.63, respectively. The present work is of potential value for delivering net zero.

A study into how thickness, infrared intensity, and airflow affect drying kinetics, modeling, activation energy, and quality attributes of apple slices using infrared dryer.

Drying is a widely recognized process that reduces the need for storage and shipping weight, keeps free water out of the product, and prolongs its shelf life. An infrared dryer was designed to dry apples under different drying conditions. Apple slices of 6-, 4-, and 2-mm thicknesses were dried at intensities 0.130, 0.225, and 0.341W/cm2 and airflow 1.0, 0.5, and 1.5m/s. The dehydrating period was prolonged with higher airflow and shortened with higher infrared intensity (IR). The shortest dehydrating period was verified by 190min at 0.341W/cm2, 0.5m/s under 2mm thickness. Increasing the sample thickness from 2 to 4 mm and then to 6mm resulted in an 84% and 192% increase in drying time, respectively. Dehydrated apples had water activity values ranging from 0.30 to 0.40. The shrinkage ratio increased with an increase in infrared radiation intensity. However, it decreased with an increase in air velocity, while the rehydration ratio decreased with an increase in radiation intensity and increased with an increase in air velocity. Regarding total color change, apple slice thickness was a major factor. The effective diffusivities varied between 2.6 and 9.0 𝗑10-10 m2/s under different drying conditions. The dehydrating curves of apples were best described by the model developed by Midilli etal.

Low-mass Population III Star Formation due to the HD Cooling Induced by Weak Lyman–Werner Radiation

Lyman–Werner (LW) radiation photodissociating molecular hydrogen (H2) influences the thermal and dynamical evolution of the Population III (Pop III) star-forming gas cloud. The effect of powerful LW radiation has been well investigated in the context of supermassive black hole formation in the early Universe. However, the average intensity in the early Universe is several orders of magnitude lower. For a comprehensive study, we investigate the effects of LW radiation at 18 different intensities, ranging from J LW/J 21 = 0 (no radiation) to 30 (H-cooling cloud), on the primordial star-forming gas cloud obtained from a three-dimensional cosmological simulation. The overall trend with increasing radiation intensity is a gradual increase in the gas cloud temperature, consistent with previous works. Due to the HD cooling, however, the dependence of gas cloud temperature on J LW deviates from the aforementioned increasing trend for a specific range of intensities (J LW/J 21 = 0.025–0.09). In HD-cooling clouds, the temperature remained below 200 K during 105 yr after the first formation of the high-density region, maintaining a low accretion rate. Finally, the HD-cooling clouds have only a low-mass dense core (above 108 cm−3) with about 1–16 M ⊙, inside of which a low-mass Pop III star with ≤0.8 M ⊙ (a so-called “surviving star”) could form. The upper limit of star formation efficiency Mcore/Mvir,gas significantly decreases from 10−3 to 10−5 as HD cooling becomes effective. This tendency indicates that, whereas the total gas mass in the host halo increases with the LW radiation intensity, the total Pop III stellar mass does not increase similarly.

Influence of radiation mode and intensity on the protective performance of firefighting boots

In the process of firefighting and emergency rescue, firefighting boots are one of the most important personal protective equipments (PPEs) for firefighters to protect their feet and legs from thermal radiation injury. In this work, the self-designed long-term thermal radiation setup was employed to measure the critical failure temperature for firefighting boots with various radiation intensities and reveal the performance influence of radiation intensity on critical parameters, including the temperature rise inside or outside, hardness and mass loss of firefighting boots, when radiating from the front, the side or all around. The Henriques Burn Integral (HBI) was adopted to predict second-degree skin burn injury. The results show that with the radiation intensity increasing, the temperature inside or outside increases, and the hardness and mass of firefighting boots decrease. The declined magnitude of hardness goes down as the radiation time lapses. The second-degree burn time is advanced with the increase in radiation intensity. The second-degree skin burn time at 7 kW/m2 is 166s and the predicted value was short. When the surface temperature of firefighting boots is up to about 140 °C, the boots’ toe color appears from bright yellow to scorched black, along with the bulge phenomenon, indicating its protection effect loss. At the identical radiation intensity, the temperature rises of the boots radiating from all around are larger than those of other conditions, and the maximum temperature of the inner surface of the boots radiating from the side at 7 kW/m2 is 1.9 times higher than that radiating from the front, indicating that the side of firefighting boots is weakness in an actual fire.

High conductivity characteristics of phosphorus-doped nanocrystalline silicon thin films by KrF pulsed excimer laser irradiation method.

The microstructure and high conductivity properties of phosphorus-doped nanocrystalline silicon films were investigated on samples prepared by a plasma-enhanced chemical vapor deposition technique and the KrF pulsed excimer laser irradiation method. The results of Fourier transform infrared spectroscopy and Raman spectroscopy show that Si nanocrystallites with an average diameter of 2 nm to 3 nm are formed in the film. The degree of crystallinity increases with the increase of laser radiation intensity, while the content of hydrogen decreases gradually. More phosphorus atoms are substitutionally incorporated into the nc-Si dots under higher laser irradiation fluence, which is responsible for the high dark conductivity. By controlling the laser fluence at 1.0 J cm-2, the dark conductivity as high as 25.7 S cm-1 can be obtained. Based on the measurements of temperature-dependent conductivity, the carrier transport processes are discussed. The phosphorus doping and the increase of electron concentration are considered to be the reason for high dark conductivity and extremely low conductivity activation energy.

Design, fabrication, and performance assessment of a novel solar air heater based on recycled materials

In this paper, a solar air heater (SAH) is designed using recyclable materials, and its performance is analyzed. The device is composed of an absorbing plate made up of 36 cans of soda and an equal number of tins with bodies covered with black color and has resistivity against high temperatures. The laboratory research revealed that the collector's efficiency is enhanced considerably by increased airflow speed and the heat transfer coefficient between the absorbing plane and air. In addition, the effects of the radiation intensity and mass flow rate on parameters such as the absorbed heat, temperature difference, and thermal efficiency are investigated. The derived results for mass flow rates of 0.0104 (kgs-1) and 0.0078 (kgs-1) indicate that all mentioned parameters increase the radiation intensity. Furthermore, the thermal efficiency and the absorbed heat are increased by increasing the mass flow rate, while a reduced mass flow rate increases the temperature difference parameter. Moreover, studying the charts demonstrates that the tins absorb a larger portion of the sun's radiation and, consequently, enhance thermal transfer compared with the soda cans. Irreversibility increased with increasing radiation intensity. At 300 radiation intensity, the highest thermal and exergetic efficiencies occurred.

Laser-induced Bragg resonances in ferrit/semiconductor heterostructure

The paper reports on laser-induced Bragg resonances in the spectrum of magnetostatic waves in a heterostructure based on a ferrite film [yttrium iron garnet (YIG)] with periodic strips of semiconductor material (Si) on the surface. Laser irradiation of such a structure leads to the formation of Bragg bandgaps due to the modulation of the Si conductivity on the YIG surface, and the magnitude modulation increases with increasing laser radiation intensity. It is shown that an increase in laser radiation intensity also leads to an increase in the depth and frequency shift of the bandgaps.

Performance assessment of hybrid PEMFC-solar energy integrated hybrid multi-generation system for energy production sport buildings.

Polymer membrane electrolyzers are a useful tool for producing hydrogen, which is a renewable energy source. Unmanned aerial vehicle (UAV) fuel cells can be powered by the hydrogen and oxygen produced by the electrolyzer. The primary losses of polymer membrane electrolyzers must therefore be identified in order to maximize their performance. A renewable-based multi-energy system considers power, cooling, heating, and hydrogen energy as utility systems for integrated sport buildings. In this study, we investigate the effect of radiation intensity, current density, and other performance factors on the rate of hydrogen production in water electrolysis using a polymer membrane electrolyzer in combination with a solar concentrator. The findings showed that a rise in hydrogen generation led to an increase in current density, which increased the electrolyzer's voltage and decreased its energy and exergy efficiencies. The voltage was also increased, and the electrolyzer's efficiency was enhanced by a rise in temperature, a decrease in pressure, and a reduction in the thickness of the nafion membrane. Additionally, with a 145% increase in radiation intensity, hydrogen production increased by 110% while the electrolyzer's energy and exergy efficiencies decreased by 13.8% as a result of the electrolyzer's high input electric current to hydrogen output ratio.

Experimental performance and evaluation of direct evaporative cooling system coupled with a desiccant wheel in a closed greenhouse

The greenhouse is one of the most advanced technologies protecting products against inconvenient climates. However, high humidity and temperature throughout the summer, particularly in closed greenhouses, have a reverse effect on the crops. In such conditions, reducing the temperature inside the greenhouse seems indispensable. Therefore, in this study, two different patterns of cooling systems, namely, direct evaporation and mixed direct evaporative desiccant rotatory wheel, were designed and developed in Tehran. The results of these models were evaluated, compared, and modeled in TRNSYS. Subsequently, for performance prediction of these models, they were examined in closed greenhouses located in 5 regions in Iran: Astara, Ahvaz, Bandar-abbas, Tehran, and Shiraz. The temperature and humidity in different parts of the greenhouse were measured and reported to assess the performance of these two systems in terms of the capability to supply the required cooling load, energy consumption, and functional expenses. The experimental results indicated that the direct evaporative cooling system isn't acceptable for cooling the closed greenhouse in the preceding regions. This system in conventional greenhouses can be applicable only in Astara, Tehran, and Shiraz. Although all traditional greenhouses in Tehran use a direct evaporative cooling pad system, such a system cannot be used for cooling the closed greenhouses. Also, findings of the present study indicated that despite the 10% increase in radiation intensity and 7% increase in temperature in the case of evaluating the mixed evaporative desiccant rotatory wheel system, the temperature changes of greenhouse in this system followed a similar behavior, and 8% reduction in functional expenses was also confirmed.

End-of-day Far-red Lighting with a Low Daily Light Integral Increases Stem Length But Does Not Promote Early Leaf Expansion for Petunia ×hybrida Seedlings

Greenhouse production of high-quality young annual bedding plants (plugs) at northern latitudes often requires supplemental lighting to compensate for a low natural daily light integral (DLI), but radiation interception by plugs is limited by a low leaf area index. Some species show an increase in leaf area in response to growth under a low ratio of red to far-red radiation (R:FR), and an early increase in leaf area may allow for more effective radiation capture by seedlings and a reduction in wasted radiation. Thus, the objective of this study was to examine the effects of end-of-day far-red (EOD-FR) radiation treatments varying in intensity, R:FR (600–700 nm/700–780 nm), and duration on early leaf expansion and plug quality for petunia (Petunia ×hybrida) ‘Wave Purple’ and ‘Dreams Midnight’. Seedlings were grown in 128-cell trays in a common greenhouse environment under a simulated winter DLI (∼5.3 mol·m−2·s−1) and received one of four EOD-FR treatments, control conditions (no EOD-FR or supplemental lighting), or supplemental lighting (target photosynthetic photon flux density of 70 μmol·m−2·s−1). The EOD-FR treatments were provided for 3 weeks on cotyledon emergence and included the following: 10 μmol·m−2·s−1 of far-red radiation for 30 minutes with a R:FR of ∼0.8 (EODFL), 10 or 20 μmol·m−2·s−1 of far-red radiation for 30 minutes with a R:FR of ∼0.15 (EOD10:30 and EOD20:30, respectively), or 20 μmol·m−2·s−1 of far-red radiation for 240 minutes with a R:FR of ∼0.15 (EOD20:240). Destructive data were collected 14 and 21 days after cotyledon emergence. Seedlings that received EOD-FR treatments did not show any increase in leaf area compared with control or supplemental lighting treatments. Stem length generally increased under EOD-FR treatments compared with supplemental lighting and control treatments; greater elongation was observed when the R:FR decreased from 0.8 to 0.15, and when treatment duration increased from 30 minutes to 240 minutes. However, at a R:FR of 0.15 and a treatment duration of 30 minutes, an increase in far-red radiation intensity from 10 to 20 μmol·m−2·s−1 did not promote further stem elongation resulting in similar stem lengths for both cultivars under EOD10:30 and EOD20:30. Results of this study indicate that under low DLIs, EOD-FR radiation applied in the first 3 weeks of seedling production does not promote early leaf area expansion, and generally decreases seedling quality for petunia. As responses to far-red radiation may vary based on study taxa, incident radiation, and DLI, future research examining EOD-FR–induced morphological changes is warranted.

A Highly Efficient Electromagnetic Wave Absorption System with Graphene Embedded in Hybrid Perovskite.

To cope with the explosive increase in electromagnetic radiation intensity caused by the widespread use of electronic information equipment, high-performance electromagnetic wave (EMW)-absorbing materials that can adapt to various frequency bands of EMW are also facing great demand. In this paper, CH3NH3PbI3/graphene (MG) high-performance EMW-absorbing materials were innovatively synthesized by taking organic-inorganic hybrid perovskite (OIHP) with high equilibrium holes, electron mobility, and accessible synthesis as the main body, graphene as the intergranular component, and adjusting the component ratio. When the component ratio was 16:1, the thickness of the absorber was 1.87 mm, and MG's effective EMW absorption width reached 6.04 GHz (11.96-18.00 GHz), achieving complete coverage of the Ku frequency band. As the main body of the composite, CH3NH3PbI3 played the role of the polarization density center, and the defects and vacancies in the crystal significantly increased the polarization loss intensity; graphene, as a typical two-dimensional material distributed in the crystal gap, built an efficient electron transfer channel, which significantly improved the electrical conductivity loss strength. This work effectively broadened the EMW absorption frequency band of OIHP and promoted the research process of new EMW-absorbing materials based on OIPH.

Experiment study on startup characteristics and operation performance of PV/T solar assisted heat pump water heater system driven by direct current variable frequency compressor

The use of renewable energy can alleviate climate warming and environmental pollution. PV/T (photovoltaic/thermal) system has been widely concerned and rapidly developed owing to its capability of generating electric and thermal energy simultaneously. In the article, a PV/T solar assisted heat pump water heater system driven by direct current variable frequency compressor was proposed to meet the growing needs of residents for domestic hot water. This system was tested in different working conditions in Lanzhou, and the startup characteristics and operation performance were evaluated. The results indicate that at the same ambient temperature, low speed is conducive to the continuity of the refrigerant cycle and improves the system performance. In this system, the initial water temperature of the water tank was 23.1 °C and after 2.5 h it reached 53 °C. The average power generation efficiency is 13.64%, the average thermal efficiency is 26.42%, the overall efficiency is 62.69% and the average COP (coefficient of performance) is 4.87. Compared with traditional PV (photovoltaic) modules, the average temperature reduction is 11.2 ℃. With the increase of solar radiation intensity, the electrical power of the system will increase and the electrical efficiency will decrease. The average daily electrical efficiency of PV/T system is 13.64%, which is 6.25% higher than that of uncooled PV panel. In addition, controlling a proper compressor speed is crucial for enhancing system performance. The PV/T collector can remarkably reduce the temperature of PV panel, improve power generation efficiency and comprehensive utilization efficiency of solar energy.

Numerical investigation of the entropy generation analysis for radiative MHD power-law fluid flow of blood through a curved artery with Hall effect

In the last few decades, mortality rate due to blood vessel diseases has hiked rapidly and it is almost one-third of total mortalities. Identifying the vascular geometry and hemodynamic blood flow inside the artery is essential for preventing vascular disease progression. By motivating vascular diseases effects on the human body, a mathematical model has been developed to discuss the blood flow phenomena and entropy estimation in the stenosed curved artery in the presence of a magnetic field and the Hall effect. The patient-specific condition of elliptic shape stenosis has been considered at the arterial wall. Blood is considered in the artery as two-phases; core and plasma region. Power-law fluid has been considered for core region fluid, while, Newtonian fluid is considered in the plasma region. The non-dimensional governing equations have been discretized using the second-order central difference method. Then, Stone's strongly implicit scheme is used in the ‘MATLAB’ software to solve a system of nonlinear partial differential equations (PDEs). A computing error tolerance of has been set for each iteration step throughout the computing process. The influence of various parameters such Hall parameter (m), Brinkman number (Br), flow behavior index (q), Radiation parameter (N), magnetic field (M), arterial curvature, etc., have been discussed graphically. The present study concludes that the heat transfer rate enhances with the increase in the Hall parameter values while wall shear stress reduces with it. In addition, the chances of stenosis deposition rise for highly curvature arteries, and also blood produces more entropy with the increase in viscous heating and thermal radiation intensity. Results from the current computational study will aid clinical researchers in making more accurate predictions about the prevalence of vascular diseases.

Emergy evaluation of a solar-powered cascade system for dehumidification, cooling and heating in hot summer and cold winter areas of China

A solar-powered cascade system is proposed for dehumidification, cooling and heating in hot summer and cold winter areas of China. To evaluate the energy, environmental and economic sustainability of the system, the emergy evaluation of the proposed system is analyzed and compared with different energy sources. The effects of solar radiation intensity, air temperature and relative humidity on the emergy performance of the system are discussed. The results show that the input total emergy and transformity of the proposed system are 9.88 × 1016 sej/y and 4.75 × 105 sej/J, which are lower than that of the systems powered by other energy. The environmental load ratio and emergy sustainability index are the highest when the system is powered by solar energy, with the value reaching 1.33 and 1.66, respectively. According to parameter sensitivity analysis, the total emergy input decreases by 6.31% and the emergy saving ratio increases by 29.09% as the increase of solar radiation intensity. The system has the best emergy performance at air temperature of 26.18 °C. The system has lower environmental load and higher sustainability in lower relative humidity climate. This work proves the viability and sustainability of the novel cascade system.

Experimental and Numerical Investigation of the Effect of Water Cooling on the Temperature Distribution of Photovoltaic Modules Using Copper Pipes

In hot climates, PV efficiency drops dramatically if the surface temperature of the panels rises over a specific limit. Consequently, a cooling system is required to preserve PV modules as close to their operating temperature as feasible. For this purpose, the influence of an increase in PV surface temperature on PV performance was studied experimentally and numerically at the Research Institute of Petroleum Industry (RIPI) in July. The current study uses a cooling system consisting of rows of copper pipes connected to the PV backside. The experiments are conducted for four distinct scenarios, each with a different input fluid temperature ranging from 19.5 to 61 °C. The parametric analysis focuses on three influential factors: ambient temperature, solar radiation, and fluid inlet temperatures. In addition, other inputs are configured in accordance with the experimental conditions. The results showed that installing a cooling water system decreased the PV surface temperature from 60.20 °C to 40.24 °C at 9:00 am and from 73.98 °C to 73.33 °C at 1:30 pm. Furthermore, the electrical, thermal, overall, and exergy efficiencies drop as radiation intensity and water inlet temperature increase. In addition, the numerical results are validated with the experimental ones, and it shows high degrees of concordance.

Predicting the Effects of Future Climate Change on the Potential Distribution of Eolagurus luteus in Xinjiang

Eolagurus luteus (yellow steppe lemming Eolagurus luteus Eversmann, 1840) is a keystone species in the desert steppe of northern Xinjiang, one of the regions most affected by global climate change. Their behavior of eating grassland vegetation and digging holes has resulted in the reduction of grassland vegetation and soil erosion in northern Xinjiang, which has seriously affected the ecological balance of the grassland in northern Xinjiang, and pathogens carried by E. luteus pose a great threat to human health. Climate change exacerbates the uncertainty of the outbreak of E. luteus. Predicting the suitable habitat area of this species under climate change scenarios will help farmers and herders deal with the potential threat of an E. luteus outbreak. In this study, 117 actual occurrence points of E. luteus were used, and 24 climate models, 6 soil factors and 3 topographic factors from the Coupled Model Intercomparison Project (CMIP6) were taken into account. Combining the MaxEnt model and the overlay analysis function of ArcGIS software, the potential geographic distribution of E. luteus in 2030 and 2050 for the green development path (SSP126), the intermediate development path (SSP245), the regional competition path (SSP370), and the high development path (SSP585) was predicted. The change trend of the suitable area and distribution pattern of E. luteus in Xinjiang under future climate conditions was analyzed, and the main environmental factors affecting the distribution of E. luteus are discussed. The results show that the average area under curve (AUC) and true skill statistics (TSS) of the MaxEnt model are 0.993 and 0.8816, respectively, indicating that the model has a good prediction effect. The analysis of environmental factors showed that the main environmental factors affecting the potential geographical distribution of E. luteus are average annual temperature, isotherm, average temperature in the wettest quarter, average temperature in the driest quarter, and precipitation variation coefficient. With the increase of radiation intensity and time, the suitable areas of E. luteus will continue to decrease. Especially in the 2050s under the SSP585 scenario, the middle and high suitable areas will decrease by 2.58 × 104 km2 and 1.52 × 104 km2, respectively. Although the potential habitat area of E. luteus is shrinking, the future threat of E. luteus to grassland ecological security and human health should not be underestimated due to ecological adaptation of the community and the frequent occurrence of extreme weather. Therefore, studying changes in the potential geographic distribution of E. luteus under climate change scenarios and developing appropriate monitoring programs are of great importance for grassland ecological security and human health. This study fills in the gaps in the study of the potential geographical distribution of E. luteus and provides methodological and literature support for the study of the potential geographical distribution of other rodents.

Effects of ultraviolet and infrared radiation absence or presence on the aroma volatile compounds in winegrape during veraison

Light environmental factors have been identified to influence grape aromas greatly. Among them, the effect of non-visible light on grape aroma compounds has scarcely been investigated during grape growth and development. In the present study, ultraviolet (UV) or infrared (IR) radiation was eliminated in the grape bunch zone, and the grape bunches were irradiated with UV or IR light in vitro. The effect of UV and IR radiation on the grape aroma profile of the Cabernet Sauvignon variety was assessed by headspace solid phase microextraction gas chromatography mass spectrometer (HS-SPME GC–MS). A total of 16 aroma compounds were identified in the grape berries under UV radiation absence (UV-) or IR radiation absence (IR-). They were classified into aliphatic alcohols, aliphatic acids, benzenolds, aldehydes, and monoterpenes. A total of 23 aroma compounds were identified in the grape berries under UV radiation presence (UV+) or IR radiation presence (IR+), which were classified into aliphatic alcohols, aliphatic ketones, aliphatic esters, aliphatic acids, monoterpenes, aldehydes, volatile phenols, and other volatiles. Linalool and hexanal aroma compounds were the most responsive to UV- and UV+, according to OPLS-DA analysis. Hexanal was increased by UV- and decreased by UV+, thus was negatively correlated with UV radiation. Benzaldehyde and 2-decanone were also found as the main differing aroma compounds according to VIP scores in the IR- and IR+, respectively. The significant differences of aroma compounds in three UV and IR intensities were also observed by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS). The content of acetic acid, 2-methylbutanal, and pentanal were reduced with the radiation intensity increase, and the content of 2–3-butanedione, butyl acetate, and 1-hexanol was enhanced, especially with UV radiation. This study improves our understanding of the non-visible light role in volatile aroma compound accumulation and further expands on the useful wavelength for plant growth and development. Our study provides a theoretical basis for non-visible light field management and indoor plant growth applications.