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In this study, we examine the Russian automatic lunar missions "Luna-25," "Luna-26," and the scientific objectives and landing site of the "Luna-27″ spacecraft. The landing of "Luna-27″ is planned directly in the South Polar region, which, due to ballistic and engineering requirements, is confined to a sector extending from 51°E to 1°W in longitude and from 83°S to 79°S in latitude. This area is characterized by complex terrain, and to identify suitable landing territories, a suitability map has been created that takes into account the distribution of slopes, the degree of illumination, and visibility of Earth. A total of five sites measuring 30 × 15 km (landing ellipse) within the considered region meet such scientific and technical requirements as slope distributions of less than 7–10°, sunlight illumination of more than 35 %, and Earth visibility of more than 50 %. All landing sites are ranked by priority from 1 to 5 depending on the content of water equivalent of hydrogen (WEH) in the lunar soil. Site №1, by its characteristics, is considered the best and may be chosen as the primary landing site, while sites №2 and №3 could serve as backups. It is demonstrated that with increased landing precision, with a deviation probability from the given point up to 0.5 km, the number of suitable landing sites satisfying primarily scientific rather than engineering-technical safety criteria, which are also inherently met, significantly increases. • Landing zone: 51°E to 1°W, 83°S to 79°S. • Map identifying suitable area for spacecraft landing. • Slope distribution, Sun illumination, Earth visibility, water-hydrogen content. • Only five sites (30 × 15 km ellipsoids) meet criteria. • Landing accuracy crucial for meeting scientific needs. [ABSTRACT FROM AUTHOR]

Despite the importance of the Amazonian rainforests in the global carbon cycle, their phenological responses measured by large field-of-view satellite sensors are still not completely understood. In this scenario, close-to-nadir observations at high spatial and temporal resolutions made by satellite constellations may contribute to improve this knowledge. Here, we investigated the sensitivity of five vegetation indices (VIs) to canopy shadows over 15 protected forests of the Amazon, and the possible existence of coupled effects of solar illumination and vegetation phenology on the VI determination. The VIs are the Enhanced Vegetation Index (EVI), Green-Red Normalized Difference (GRND), Modified Photochemical Reflectance Index (MPRI), Normalized Difference Vegetation Index (NDVI), and RedEdge Normalized Difference (REND). They were calculated from 432 images obtained in 2022 by the Planet’s eight-band SuperDove instrument. Few daily images acquired on the same day with distinct Solar Zenith Angle (SZA) were used to disentangle the effects of solar illumination from those of vegetation phenology. The results showed the presence of coupled effects of solar illumination and vegetation phenology on the EVI determination regardless of the site location, especially over dense forests. Such effects were not observed significantly in the GRND, MPRI, NDVI, and REND data. When the vegetation phenology was kept fixed in the analysis, solar illumination generated pseudo-greening effects from the EVI, even for small differences in SZA between daily observations. As the most sensitive VI to illumination conditions, the EVI increased from the beginning to the end of the dry season tracking solar angles and shade fractions. This dry-season trend was not observed for GRND, MPRI, NDVI, and REND, which presented low correlations with SZA and shade fractions. These four VIs were correlated with each other over most sites, which explained the agreement observed between their seasonal profiles. From the analysis of 15 sites distributed throughout the Amazon, our findings did not confirm patterns of large-scale greening at the end of the dry season. Local changes in greening (vegetation productivity) and browning were captured by the VIs over a few sites but in different periods of the dry season (June to September). At the high spatial scale of SuperDove observations, our results highlight the necessity of correcting solar and, in some cases, terrain illumination effects on the EVI before retrieving phenological metrics over the Amazon.

Energy efficiency of a solar illuminated vertical farm is investigated considering different illumination scenarios. The analysis considers the energy consumed by a typical vertical farming facility for heating, cooling and lighting with and without ventilation. Different illumination scenarios consider utilizing fluorescent reflectors converting green light, which is reflected by green leaved produce, to red to increase photosynthetic production, IR filters preventing solar wavelengths, which do not contribute to photosynthetic growth, to enter the facility to reduce cooling load, and light emitting diodes used as a means of complementary/main lighting. Through analyzing 5 different scenarios where these technologies are used in different combinations, the contribution of each technology is identified for 22o, 41o and 60o latitudes in the Northern Hemisphere. It was found that using IR filters is the most effective means of increasing energy efficiency, whereas the impact of using fluorescent coating to energy efficiency is limited in presence of supplementary light emitting diodes illumination. Relying solely on light emitting diodes yield a significant increase in energy consumed to grow per kg of crop. High production rate can be achieved using solar illumination with IR filters, fluorescent coatings and supplementary LED lighting with ventilation that can lead to energy savings of 22 %, 28 %, 29 % with respect to solely relying on LED illumination for 22°N, 41°N, 60°N, respectively. Whereas the corresponding savings, when no ventilation is used are 19 %, 18 %, 13.6 %, for 22°N, 41°N, 60°N, respectively. • Energy efficiency of solar illuminated vertical farms with different illumination scenarios investigated. • Energy for lighting, heating and cooling loads with and without ventilation considered. • Use of fluorescent reflectors, IR filters and LEDs as complementary/main lighting is considered. • Solar illumination with fluorescent reflectors and IR filters improve energy efficiency. • Improvement is more at higher latitudes with ventilation, which is opposite without ventilation. [ABSTRACT FROM AUTHOR]

The spectral variability of tropical forests during the Amazonian dry season is not entirely understood because of the divergent responses in Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indices (VIs) measured under-increased water deficit and high insolation. Here, we used a dataset composed of 493 cloud-free PlanetScope (PS) images to investigate possible effects of solar illumination on the dry-season variability of spectral and spatial attributes. The attributes were calculated from June to September over dense tropical forests of the Amazon. The dry-season images were obtained at nadir viewing between 2017 and 2019 over 12 selected sites representing different climatic and environmental conditions. To detect dry-season patterns of vegetation brightness with changes in the geometry of image acquisition, we applied principal component analysis (PCA) over the PS surface reflectance. We plotted the average surface reflectance (2017–2019) for each of the four PS bands and inspected the variability of two VIs with distinct levels of anisotropy to bidirectional effects: the Enhanced Vegetation Index (EVI) and the Normalized Difference Vegetation Index (NDVI). We also investigated the signal of textural metrics from Grey Level Co-occurrence Matrix (GLCM) obtained from the near-infrared (NIR) band of PS. Finally, we generated shade fractions from Spectral Mixture Analysis (SMA), correlated the spectral and spatial attributes of vegetation with solar angles, and observed the dry-season variability in reflectance and VIs over pseudo-invariant soil surfaces. The results showed the existence of solar illumination effects on PS image acquisition during the dry season of the Amazon, which affected differently the NDVI and EVI. From the beginning (June) to the end (September) of the dry season, the solar zenith angle (SZA) decreased and the solar azimuth angle (SAA) increased during the period of acquisition of the PS images. The amplitude of SZA between June and September increased towards south of the Amazon, while the amplitude of SAA increased towards north of this region. Changes in vegetation brightness from June to September were captured by PCA over some sites. Because of the overall increase in both red and NIR band reflectance, solar illumination effects were compensated during the NDVI calculation. In contrast, because the EVI is largely driven by changes in NIR reflectance, these effects contributed to increase the EVI signal at the end of the dry season. For most sites, GLCM texture mean increased towards the end of the dry season, while texture variance decreased in the opposite direction. Shade fractions decreased towards September when reduced amounts of canopy shadows were sensed by PS. EVI was more anisotropic than NDVI and presented higher negative correlations with SZA and shade fractions and higher positive correlations with SAA and texture mean. The dry-season increase in EVI with solar illumination effects was also observed over pseudo-invariant soil surfaces. From this unprecedent scale of observations at high spatial and temporal resolutions, we recommend caution when using anisotropic VIs for large-scale phenological studies over the Amazon because biophysical and non-biophysical signals may be coupled together. [ABSTRACT FROM AUTHOR]

Lidar observations of aerosol and ozone, carried out at Siberian Lidar Station (SLS) of Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences in Tomsk (56°29′ N; 85°3′ E), showed the presence of stratospheric aerosol layers over Tomsk during winter 2017–2018, signs of descending air masses, and deficit of ozone. The Aura OMI/MLS observations indicated that in December-January 2017/2018 the northern Eurasia had been under the impact of Arctic air masses from the Eastern Hemisphere with deficient total ozone (TO) and NO2 contents in the stratosphere, and low temperature in the stratosphere. Analysis of back trajectories and MLS profile-integrated TO showed that due to dynamic disturbance of the Arctic stratosphere in December 2017, cold air masses with excessive reactive chlorine (in view of deficient NO2) were exported from within the Arctic circle to the stratosphere over Tomsk. Seemingly, in the Tomsk stratosphere, after being exposed to solar radiation and to the excessive reactive chlorine (in view of NO2 deficit), and, staying chemically isolated, they evolved into chemically disturbed state, similar in ozone destruction rate to the conditions of the springtime Arctic stratosphere. The correlations between deviations in water vapor and ozone mixing ratios and number concentrations are most strong for mixing ratios, for Eureka, Ny-Ålesund, Jokioinen, St. Petersburg, and Tomsk, and for December 2017 (versus January 2018). [ABSTRACT FROM AUTHOR]

Lidar observations at Siberian Lidar Station (SLS) of the Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, in Tomsk (56.5° N; 85.0° E) showed the presence of stratospheric aerosol layers, descent of air masses, and deficit of ozone over the city during winter 2017–2018. Aura OMI/MLS data indicated that the total ozone (TO) content and NO2 content in the stratosphere over northern Eurasia, as well as the temperature in the stratosphere, were significantly lower than normal in December 2017–January 2018. Analysis of back trajectories and integrated (over profile) TO showed that the dynamic disturbance of the Arctic stratosphere in December 2017 led to the extrusion of cold air masses with excessive reactive chlorine content (in view of NO2 deficit) beyond the Arctic circle and their intrusion into the stratosphere of Tomsk. Seemingly, they were exposed to solar radiation in the stratosphere over Tomsk and, staying spatially isolated, became chemically disturbed. This state is similar to the state of the springtime Arctic stratosphere, where ozone is intensely destroyed until the final warming. [ABSTRACT FROM AUTHOR]

By using 10 years of Challenging Minisatellite Payload satellite observations, we investigate the average conditions of the interplanetary magnetic field (IMF) prevailing during the westward counter equatorial electrojet (CEJ). Equally, we compared the average IMF conditions accompanying high‐latitude field‐aligned currents of the Region 1 (R1) and Region 2 (R2). It shows that both CEJ and high‐latitude field‐aligned currents events when R2 is greater than R1 tend to happen preferably during the northward turning of the IMF Bz and the substorm recovery phase. Sunlight has an important influence on the longitudinal distribution of the equatorial electrojet (EEJ), and the effect is opposite to the tidal electric field at E region. The anticorrelation between cos 0.5(SZA) (solar zenith angle effect) average values during CEJ events and EEJ intensity is most prominent around June solstice. By using combined measurements from Challenging Minisatellite Payload and DMSP satellites, it is found that before the occurrence and in the initial phase of a subauroral polarization stream the EEJ gets enhanced, and after about 30 min it reduces in intensity. The CEJ occurrence rate more than doubles during subauroral polarization stream periods compared to normal conditions. Key Points: Both counter electrojet and R2 > R1 field‐aligned currents occur during the northward turning of the interplanetary magnetic fieldThe counter electrojet occurrence rate more than doubles during subauroral polarization stream periods than under normal conditionsThere is an anticorrelation between cos 0.5(SZA) (solar zenith angle) and eastward electrojet, most prominent around June solstice [ABSTRACT FROM AUTHOR]

The present study investigates the dependence of the local auroral electrojet (AEJ) intensity on solar illumination by statistically examining northward geomagnetic disturbances in the auroral zone in terms of the solar zenith angle χ. It is found that on the dayside, both westward and eastward electrojets (WEJ and EEJ) are more intense for smaller χ, suggesting that the solar extreme ultraviolet‐induced conductance is the dominant factor for the AEJ intensity. On the nightside, in contrast, the χ dependence of the AEJ intensity, if sorted solely by the magnetic local time, apparently depends on the station longitude and hemisphere. However, if additionally sorted by the dipole tilt angle ψ, a consistent pattern emerges. That is, although χ and ψ are correlated, the solar zenith angle and dipole tilt angle have physically different effects on the AEJ intensity. The nightside AEJ, especially the WEJ, tends to be more intense for smaller |ψ|. Moreover, whereas the WEJ is statistically more intense when the ionosphere is dark, the EEJ is more intense when it is sunlit. The preference of the WEJ for the dark ionosphere prevails widely in magnetic local time from premidnight to dawn, and therefore, it cannot be attributed to the previously proposed processes of the preferred monoenergetic or broadband auroral precipitation in the dark ionosphere. Instead, it may be explained, at least morphologically, in terms of the conductance enhancement due to the diffuse auroral precipitation, which is also prevalent from premidnight to dawn and is more intense in the dark hemisphere. Key Points: The nightside westward electrojet (WEJ) is more intense when the ionosphere is dark, and the eastward electrojet (EEJ) when it is sunlitBoth WEJ and EEJ are more intense when the dipole tilt is smaller, and this effect is comparable to the effect of solar illuminationThe preference of the WEJ intensity for the dark ionosphere likely reflects that of diffuse e‐ precipitation and ionospheric conductance [ABSTRACT FROM AUTHOR]

Abstract In this study, nitrobenzene (NB) as typical refractory organic pollutants was effectively degraded by a new green approach, which was achieved by the chemical effect of natural organic matters (NOMs) under solar illumination as a potential natural degradation process. 4-hydroxycoumarin (4HC), which is natural compound and can be extracted from many plants, was found as an efficient photosensitizer to promote the photoreduction of NB to 4-aminophenol under the solar illumination. The reaction products were definitely identified by LC-MS/MS and 1H NMR. The response spectrum of 4HC excited state (4H-chromene-2,4-diol radical, S 1) as key intermediate was also obtained by transient absorption spectroscopy (TAS) measurements, which showed that the decay time of S 1 was around 250 ps. Then, the measurements of electron paramagnetic resonance (EPR) confirmed the existence of OH. As a result, the reaction mechanism between 4HC and NB was proposed. In addition, the influence parameters such as light sources, gas surroundings, solvents, pH values were investigated to further reveal the reaction process. Graphical abstract The degradation pathway of refractory nitrobenzene in water through the natural 4-hydroxycoumarin under solar illumination. Image 1 Highlights • A new natural organic matter could be activated as reducing agent under illumination. • 4-hydroxycoumarin as natural compound was found to be an efficient photosensitizer. • The refractory nitrobenzene was degraded to 4-aminophenol by 4HC as green process. • 4HC excited state (4H-chromene-2,4-diol radical) as key intermediate was confirmed. • Reaction pathway between 4HC and NB was completely proposed by product analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel Z-type heterostructured CoS/Ag 2 MoO 4 hybrid was developed. • CoS/Ag 2 MoO 4 hybrid retains outstanding photocatalytic efficiency toward levofloxacin (LFX) antibiotic under visible illumination. • The improved photoactivity was accredited to rapid carriers transfer and separation. • The mechanism of photodegradation has been described and approved based on trapping tests. • The CoS/Ag 2 MoO 4 hybrid presented good photostability performance. Antibiotics have distinguished as hazardous emerging pollutants in environment, since they do not fully decomposed. Semiconductor photocatalysis are a promising technology for degradation of refractory organic pollutants under visible illumination. The assembly of compatible photocatalytic heterojunctions with suitable band structures achieves a promising approach for boosting the photodegradation performance. Herein, novel heterogeneous structured CoS/Ag 2 MoO 4 nanohybrids were simply constructed via precipitation and tested by range of characterization procedures (XRD, UV–vis DRS, FESEM, TEM, PL, EIS, N 2 -adsorption/desorption, and EDX). At a specific conditions (photocatalyst dose 0.3 g/L, pH natural, and levofloxacin (LFX) antibiotic concentration 20 ppm), the CoS/Ag 2 MoO 4 nanohybrid presented LFX degradation performance of 98.6 % in 90 min of solar-simulated illumination, which is exceeding that of pristine Ag 2 MoO 4 (42%) and bare CoS (27%). The mechanism together with the photodegradation pathways were clarified in details. It is demonstrated that the extended range of visible light absorption and improved charge carriers separation induced by the plasmonic Z-type heterojunction formed between Ag 2 MoO 4 and CoS were in charge for the enhancement of photocatalytic efficiency. The present work can contribute to develop effective and rapid photocatalysts for environmental requirements. [ABSTRACT FROM AUTHOR]

Ionospheric outflow from the polar cap through the polar wind plays an important role in the evolution of the atmosphere and magnetospheric dynamics. Both solar illumination and solar wind energy input are known to be energy sources of the polar wind. However, observational studies of the energy transfer from these two energy sources to the polar wind are difficult. Because of their low energy, polar wind ions are invisible to regular ion detectors onboard a positively charged spacecraft. Using a new technique that indirectly measures these low‐energy ions, we are able to estimate the energy budget of the polar wind. Our results show that solar illumination provides about 107 W of the kinetic energy of the polar wind, in addition to the energy transferred from the solar wind with a maximum rate of about 108 W. The energy transfer efficiency of solar illumination to the kinetic energy of the polar wind is about 6 to 7 orders of magnitude lower than that of the solar wind. Moreover, daily and seasonal changes in the orientation of the geomagnetic dipole axis control solar illumination over the polar cap, modulating both energies of the polar wind and energy transfer efficiencies from the two energy sources. Key Points: Quantitative energy budget of the polar wind outflow has been estimatedSolar wind energy input is the dominant energy source when the ε parameter is higher than 1010 WSolar illumination provides the kinetic energy of the polar wind outflow at a rate of about 107 W, which is lower than the solar wind [ABSTRACT FROM AUTHOR]

Abstract: By analyzing a five‐year period (2010–2014) of Defense Meteorological Satellite Program (DMSP) plasma data, we investigated ion upflow occurrence, speed, density, and flux above the polar cap in the northern hemisphere under different solar zenith angle (SZA), solar activity (F10.7), and convection speed. Higher upflow occurrence rates in the dawn sector are associated with regions of higher convection speed, while higher upflow flux in the dusk sector is associated with higher density. The upflow occurrence increases with convection speed and solar activity but decreases with SZA. Upflow occurrence is the lowest when the SZA > 100° and the convection speeds are low. While, the upflow velocity and flux show a clear seasonal dependence with higher speed in the winter and higher flux in the summer during low convection conditions. However, they are detected for the first time to be both higher in summer during high convection conditions. These results suggest that ion upflow in the polar cap is controlled by the combination of convection, solar activity, and solar illumination. [ABSTRACT FROM AUTHOR]

Polar wind outflow is an important process through which the ionosphere supplies plasma to the magnetosphere. The main source of energy driving the polar wind is solar illumination of the ionosphere. As a result, many studies have found a relation between polar wind flux densities and solar EUV intensity, but less is known about their relation to the solar zenith angle at the ionospheric origin, certainly at higher altitudes. The low energy of the outflowing particles and spacecraft charging means it is very difficult to measure the polar wind at high altitudes. We take advantage of an alternative method that allows estimations of the polar wind flux densities far in the lobes. We analyze measurements made by the Cluster spacecraft at altitudes from 4 up to 20 R E. We observe a strong dependence on the solar zenith angle in the ion flux density and see that both the ion velocity and density exhibit a solar zenith angle dependence as well. We also find a seasonal variation of the flux density. [ABSTRACT FROM AUTHOR]

Poly (3-hexylthiophene) sensitized Ag doped TiO 2 -NTs (P3HT/Ag-TiO 2 -NTs) have been prepared using the three sequential steps: two step anodization, galvanostatic deposition and spin coating techniques. The morphology and structure of P3HT synthesized by oxidative polymerization with FeCl 3 were characterized using NMR, FT-IR, SEM, XRD and optical properties of P3HT were investigated using Uv–Vis technique. The characterization results showed that the P3HT has 64.7%HT-HT configuration, mainly edge-on oriented lamellar structure and the optical band gap of 2.24 eV. Also, the morphology and structure characterization of P3HT/Ag-TiO 2 -NTs were determined by FE-SEM and XRD. The electrochemical behaviors of P3HT/Ag-TiO 2 -NTs in acetonitrile electrolyte contained I − /I 3 − were examined by utilizing Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV). The EIS results displayed that after the modification with P3HT, the value of charge transfer resistance at − 0.4 V decreases from 514 Ω cm 2 to 121 Ω cm 2 , compared to Ag-TiO 2 -NTs. Furthermore, the analysis results of EIS and Mott-Schottky for P3HT/Ag-TiO 2 -NTs under simulated solar light revealed that the charge transfer resistance decreased from 121 Ω cm 2 to 51.60 Ω cm 2 and the carrier density (N D ) increased from 8.69 × 10 21 cm − 3 to 70.1 × 10 21 cm − 3 , compared to the values under the absence of solar light. These indicate that P3HT supplies better photogenerated electron-hole pairs separation and mobility. [ABSTRACT FROM AUTHOR]

In this work, CdS quantum dots (QDs) were successfully confined in polysulfone membrane (PSM) to develop a photoactive membrane under solar illumination that was suited in wastewater remediating system. The CdS@PSM membranes were prepared using the nonsolvent induced phase separation (NIPS) approach. Optical measurements show the confinement of CdS quantum dots (QDs) in the PS matrix within the narrowest band gap (2.41 eV) at 5 wt% loading. PS has two strong emission peaks at 411 and 432 nm due to photoelectron-hole recombination on pure PSM's surface. Adding 1 wt% CdS QDs to PSM reduced the earlier peak and blue-shifted the latter, within the appearance of three emission peaks attributed to the near band-edge emission of confined CdS QDs. Overloading CdS reduced all emission peaks. Moreover, fluorimetric monitoring of •OH radicals indicates that PSM produces the least amount of photogenerated •OH radicals while CdS@PSM(5 wt%) achieved the highest productivity. Examining the developed membranes in detoxifying methylene blue (MB) from aqueous solution of natural pH 8.1 showed weak adsorption in dark over 90 min of contact while switching to solar illumination significantly photodegrade MB where the degradation efficiency starts from 49% for pure PSM to 79% for CdS@PSM(5 wt%). Influence of pH was found crucial on photodegradation efficacy. Acidic pH 3 showed the weakest photodegradation efficacy, while the alkaline pH 12 was 18.88 times more effective. The used CdS@PSM (5 wt%) was successfully photo-renovated by soaking in 10 mL of NaOH solution under Solar illumination for 15 min to be used in 4 consecutive photodegradation cycles with insignificant decrease in efficacy. These findings are promising and could lead to a high-efficiency, sustainable photocatalytic suite. [Display omitted] • CdS@PSM was successfully prepared with varied wt.% of CdS. • Fabricated membranes were tested in solar-driven wastewater remediation. • Incorporated CdS in the PSM resulted in enhanced optical properties and photocatalytic performance. • The CdS@PSM(5 wt%) membrane was found to be perform better. • The photocatalytic membranes showed durable photo-degradation performance. [ABSTRACT FROM AUTHOR]

Research on soil temperature in mangrove forest is a part of the mangrove ecosystem microclimate research. Studieson microclimate variables interaction, including soil temperature is important and interesting because it is associatedwith ecosystem and environmental changes, and the biota living in it. This study developed a mathematical modelingof soil temperatures and solar illumination in mangrove forest and the surrounding environment. Mathematicalmodeling function was constructed using data measured on three transects which different in ecosystem condition.The results showed that the mathematical modeling parameters produced the parameters of solar illumination andsoil temperatures that were difference for the three transects. Time lag of soil temperature on solar illumination wasalso diference in the three transects due to the difference of penetration of sun radiation and soil inundation by seawater. These parameters also showed the differences between the soil temperature in mangrove with the soiltemperature in terrestrial forest as studied by the former researcher. Our research demonstrated the charachteristicof soil temperature in mangrove, that was not merely controlled by sun radiation, but also it was contribute by thesea water and other factors.J Trop

The Shanghai 65 m radio telescope is currently the largest full range rotatable radio telescope in Asia. Gravity, wind and temperature are the three main factors which may have a bad effect on the reflector's surface precision. To study the effect of the thermal deformation caused by daily non-uniform temperature fields on the surface precision of the main reflector, both the temperature field and its effect were studied in detail for two typical days (January 15th and July 15th). The method to simulate temperature fields was studied initially, considering heat conduction, solar radiation, shadowing, air convection, sky radiation and ground radiation. Then, an integral parametric thermal finite element model (FEM) of the telescope was established using the ANSYS thermal analysis module. Finally, the effect of non-uniform temperature fields on the surface precision of the main reflector was estimated in terms of the Root Mean Square (RMS) deformation based on temperature transient analysis. The proposed methods and conclusions drawn can provide valuable information for thermal design, thermal monitoring and thermal control of the Shanghai 65 m radio telescope and other similar giant antenna structures. [ABSTRACT FROM AUTHOR]

Highly efficient photocatalytic reduction of environmental pollutants requires the enrichment of photogenerated electrons on the photocatalyst’s surface. Thus, proper material design and modification are needed to efficiently separate photogenerated electron/hole pairs and achieve their oriented migrations for the enrichment of photogenerated electrons on their surface. In this work, a modified photo-deposition process was developed which successfully deposited silver nanoparticles selectively on {1 0 1} facets of TiO 2 nanocrystals with co-exposed {0 0 1}/{1 0 1} facets. The synergistic effect of crystal facet engineering and the selective deposition of silver nanoparticles on {1 0 1} facets largely enhanced the separation of photogenerated carriers and enriched the presence of photo-generated electrons onto the surface of TiO 2 to a net negative-charged surface. A strong photocatalytic reduction capability of the sample was demonstrated by its superior photocatalytic reduction activity on aqueous nitrate under a simulated solar illumination. The removal ratio of aqueous nitrate reached ∼95%, and most of the reduction product was the desirable N 2 with the selectivity over 90%. These TiO 2 nanocrystal with co-exposed {0 0 1}/{1 0 1} facets and silver modification on {1 0 1} facets could also effectively remove both nitrate and various organic pollutants from water simultaneously. [ABSTRACT FROM AUTHOR]

The time-dependent temperature fields of the reflectors of the Shanghai 65 m radio telescope are investigated numerically, taking account of the non-uniform heating of the reflector surfaces due to solar illumination and the constantly changing ambient air temperature. This paper utilizes a ray casting algorithm to calculate the borderline separating the reflector areas in shadow and in sunshine, aiming to provide an accurate calculation of the solar energy absorbed. Then a ray tracing algorithm is utilized to calculate the total solar energy that is reflected by the main reflector area and received by the subreflector surface area. Finally, the solar energy is used as the main thermal load on the reflector surface to numerically examine the temperature distribution on both the main reflector and the subreflector. The results illustrate that the time-varying temperature fields of the reflectors of a radio telescope due to asymmetric solar illumination can be accurately simulated utilizing the ray casting algorithm and the ray tracing algorithm. The occurring periods and avoidance zones of the overheating of the subreflector are identified, among which the maximum temperature of the subreflector reaches 144.9°C. These dangerous observation zones should be avoided during the operation of the radio telescope. [ABSTRACT FROM AUTHOR]

By using Constellation Observing System for Meteorology, Ionosphere, and Climate satellite observations, and Global Ionosphere and Thermosphere Model simulations, the altitudinal dependences of the longitudinal differences in electron densities Ne were studied at mid-latitudes for the first time. Distinct altitudinal dependences were revealed: (1) In the northern (southern) hemisphere, there were wave-1 variations mainly in the daytime in the altitudes below 180 km, but wave-2 (wave-1) variations over a whole day above 220 km; (2) a transition (or separation) layer occurred mainly in the daytime within 180 and 220 km, showing reversed longitudinal variation from that at lower altitudes. Solar illumination was one of the plausible mechanisms for the zonal difference of Ne at lower altitudes. At higher altitudes, both neutral winds and solar illumination played important roles. The neutral winds effects accounted for the longitudinal differences in Ne in the European-Asian sector. Neutral composition changes and neutral wind effects both contributed to the formation of the transition layer. [ABSTRACT FROM AUTHOR]

Building integrated photovoltaic (BIPV) systems are an emerging approach to reduce installation costs while supplementing building energy needs. However, the physical constraints of the building architecture often prevent photovoltaic systems from being installed at their optimal orientation. Recently, it was shown that thin film photovoltaics can be designed for improved angle-dependent responsivity at specific angles. In this study, the complex impact of angular dependency on overall power output is explored based on detailed hourly solar position, location, and flux data. These results demonstrate that reducing the angular roll-off dependence can enhance overall power outputs by 30% or more in fixed orientation configurations depending on the geographical location, orientation, and angle-dependent roll-off characteristics. [ABSTRACT FROM AUTHOR]