Open Air Temperature Research Articles

Achieving a solar-to-chemical efficiency of 3.6% in ambient conditions by inhibiting interlayer charges transport

Efficiently converting solar energy into chemical energy remains a formidable challenge in artificial photosynthetic systems. To date, rarely has an artificial photosynthetic system operating in the open air surpassed the highest solar-to-biomass conversion efficiency (1%) observed in plants. In this study, we present a three-dimension polymeric photocatalyst achieving a solar-to-H2O2 conversion efficiency of 3.6% under ambient conditions, including real water, open air, and room temperature. The impressive performance is attributed to the efficient storage of electrons inside materials via expeditious intramolecular charge transfer, and the fast extraction of the stored electrons by O2 that can diffuse into the internal pores of the self-supporting three-dimensional material. This construction strategy suppresses the interlayer transfer of excitons, polarizers and carriers, effectively increases the utilization of internal excitons to 82%. This breakthrough provides a perspective to substantially enhance photocatalytic performance and bear substantial implications for sustainable energy generation and environmental remediation.

One‐Pot Access to Tetrasubstituted 2‐Aminothiophenes via Regio‐ and Chemoselective Domino Reactions of Dithioesters with Fumaronitrile at Room Temperature

AbstractHerein, we report a one‐pot viable protocol to synthesize tetrasubstituted 2‐aminothiophenes engaging readily accessible α‐enolic dithioesters and abundant fumaronitrile under transition metal‐free conditions at room temperature in open air. The reaction proceeds via successive Michael‐type addition/intramolecular cyclization/isomerization cascades. The added features are benign conditions, exclusive regio‐ and chemoselectivity, excellent atom‐/step‐economy, easy purification, and tolerance of wide range of functional groups of a diverse electronic and steric nature. This protocol not only provided a robust and modular approach to various 2‐aminothiophenes in moderate to excellent yields, but also demonstrated the potential of dithioesters and fumaronitrile in the challenging intermolecular cross‐coupling reactions widening the arsenal of synthetic methods.

Effect of solvent and auxiliary ligand on catecholase activities of Mn(III) complexes: A comparative study

A mononuclear Mn(III) complex with composition [MnIIIL(Cl)] (1) has been utilized to prepare two new complexes, [MnIIIL(N3)(CH3OH)] (2) and [MnIIIL(μ1,3-NCS)]n (3), by substitution of the auxiliary ligand. The ligand utilized for preparation of 1 is a Schiff base (H2L), obtained by 2:1 condensation of 3-Chlorosalicylaldehyde and ethylene diamine in methanol. The chloride anion, present in the coordination sphere of the central metal ion in 1 has been replaced by two other auxiliary ligands, azide and thiocyanate, in 2 and 3, respectively. All of the three complexes behaved as bio-functional models of catechol oxidase toward oxidation of 3,5-di-tert butyl catechol (3,5-DTBC). A detailed kinetic investigations were carried out for 2 and 3 in methanol, acetonitrile and N,N′-Dimethyl formamide (DMF) separately and the corresponding turn-over numbers have been determined. The ESI-MS spectra of the substrate-catalyst mixtures in acetonitrile and methanol confirmed formation of catecholate bound Mn(III) intermediate in the mass spectral time scale. The progress of the catechol oxidation was monitored by 1H-NMR spectroscopy with the reaction mixtures containing complex-substrate ratio at 1:20 after stirring in acetonitrile as well as methanol at room temperature in open air. NMR spectral data confirmed completion of the process in 90 minutes and 45 minutes for 2 and 3, respectively. Notably, in absence of any of these complexes, aerobic oxidation of 3,5-DTBC to the corresponding quinone is negligible even after twenty four hours of mixing in the same solvent. This observation is a clear indicative of high catalytic efficiencies of the prepared complexes.

Stable Room Temperature Nitrenes Created by Photolysis of Crystalline 4-Azido-2,3,5,6-tetrafluorobenzoic Acid

The structure, spectroscopy, and photochemistry of 4-azidobenzoic acid (4ABC) and its perfluorinated analog 4-azido-2,3,5,6-tetrafluorobenzoic acid (4F4ABC) are characterized in frozen glasses and crystals. Photolysis of the parent azides leads to the production of nitrenes and other spin species that are probed by electron paramagnetic resonance and optical spectroscopy. Shifts in the absorption spectra for both the parent azides and the nitrenes were well reproduced using density functional calculations. Photolysis generates ∼10× higher yield of the triplet nitrene relative to the quintet and radical side-products in 4F4ABC, while the opposite ratio is observed in 4ABC. An annealing step further suppressed the side-products in 4F4ABC, creating a solid where nitrenes were the dominant spin species. The nitrene in the 4F4ABC crystal has a 1/e lifetime of 20 days at room temperature in open air. This stability makes it possible to photopattern nitrene centers into a single crystal and characterize their photoluminescence. Multiple observations suggest that the remarkable stability in the 4F4ABC crystal is a consequence of crystal packing that traps N2 molecules adjacent to the nitrene. The ability to create stable, solid-state nitrene samples may provide a route to organic high-spin materials with potential applications in spintronics and quantum information science.

High-performance all-inorganic CsPbBr3 quantum dots with a low-threshold amplified spontaneous emission.

All-inorganic halide perovskite CsPbX3(X = Br/Cl/I)quantum dots have gained a considerable attention in the optoelectronic fields. However, the high cost and poor stability of the prepared CsPbX3 quantum dots (QDs) are inevitable challenges for their future practical applications. And the high-performance CsPbX3 QDs are always needed. Herein, a facile and low-cost synthesis scheme was adopted to prepare the CsPbBr3 QDs modified by lead bromide (PbBr2) and tetraoctylammonium bromide (TOAB) ligands at room temperature in open air. The prepared CsPbBr3 QDs exhibited a high photoluminescence quantum yield (PLQY) of 96.6% and a low amplified spontaneous emission (ASE) threshold of 12.6 µJ/cm2. Stable ASE intensity with little degradation was also realized from the CsPbBr3 QDs doped with PMMA. Furthermore, the enhanced ASE properties of the CsPbBr3 QDs-doped PMMA based on distributed feedback (DFB) substrate was achieved with a lower threshold of 3.6 µJ/cm2, which is 28.6% of that of the (PbBr2 + TOAB)-treated CsPbBr3 QDs without PMMA. This work exhibits a promising potential in the on-chip light source.

Regio- and Chemoselective Access to Dihydrothiophenes and Thiophenes via Halogenation/Intramolecular C(sp2)-H Thienation of α-Allyl Dithioesters at Room Temperature.

An operationally simple, practical, and efficient cascade approach employing α-allyl dithioesters and NBS/NIS has been achieved to access a series of dihydrothiophenes and thiophenes containing diverse functional groups of different electronic and steric natures in good to excellent yields at room temperature in open air. The reaction proceeds via the electrophilic addition of a halogen source (NBS/NIS) to an allylic double bond, followed by intramolecular regio- and chemoselective S-cyclization. This protocol avoids potential toxicity and tedious work-up conditions, and features easy synthesis from readily available starting materials under catalyst-free conditions. Furthermore, 4,5-dihydrothiophenes were aromatized to thiophenes by treatment with KOH in DMF at room temperature. A probable mechanism for the formation of dihydrothiophenes and thiophenes from α-allyl dithioesters has been suggested. Notably, a large-scale experiment and the transformations of products indicated the potential utility of this reaction compared to competing processes for the synthesis of 4,5-dihydrothiophenes and thiophenes.

2 + 3] Annulative Coupling of Tetrahydroisoquinolines with Aryliodonio diazo compounds To Access 1,2,4-Triazolo[3,4-a]isoquinolines

Base promoted one-pot annulative coupling of 1,2,3,4-tetrahydroisoquinolines (THIQs) with hypervalent iodine(III) species aryliodonio diazo compounds has been devised for the direct construction of 1,2,4-triazolo[3,4-a]isoquinoline derivatives at room temperature in open air for the first time. This approach involves [2 + 3] cascade annulation of nucleophilic THIQ with an electrophilic aryliodonio diazo compound via N-H and α-C1(sp3)-H difunctionalization of THIQ.

Evaluating the Impact of Nitrogen Application on Growth and Productivity of Maize Under Control Conditions.

Climatic conditions significantly affect the maize productivity. Among abiotic factors, nitrogen (N) fertilizer and temperature are the two important factors which dominantly affect the maize (Zea mays L.) production during the early crop growth stages. Two experiments were conducted to determine the impact of N fertilizer and temperature on the maize growth and yield. In the first experiment, the maize hybrids were screened for their sensitivity to temperature variations. The screening was based on the growth performance of the hybrids under three temperatures (T1 = ambient open-air temperature, T2 = 1°C higher than the ambient temperature, and T3 = 1°C lower than the ambient temperature) range. The results showed that an increase in temperature was resulted less 50% emergence and mean emergence (4.1 and 6.3 days, respectively), while emergence energy and full emergence were higher (25.4 and 75.2%, respectively) under the higher temperature exposure. The results showed that Syngenta 7720 and Muqabla S 25W87 were temperature tolerant and sensitive maize hybrids, respectively. The second experiment was carried out to study the response of the two selected maize hybrids (Syngenta 7720 and Muqabla S 25W87) to four N fertilizer applications. The results revealed that the maximum N use efficiency (19.5 kg kg−1) was achieved in maize hybrids with low N application (75 kg N ha−1 equivalent to 1.13 g N plant−1). However, the maximum maize grain yield (86.4 g plant−1), dry weight (203 g plant−1), and grain protein content (15.0%) were observed in maize hybrids that were grown with the application of 300 kg N ha−1 (equivalent to 4.52 g N plant−1). Therefore, it is recommended that the application of 300 kg N ha−1 to temperature tolerant maize hybrid may be considered best agricultural management practices for obtaining optimum maize grain yield under present changing climate.

Efficient synthesis of functionalized 2-iminothiazolines by ultrasonication under solvent-free conditions and access to 5-aryl-2-iminothiazolines

An ultrasound assisted methodology has been developed for rapid synthesis of a series of biologically important 2-iminothiazolines from easily available α-bromoketones and thioureas under solvent- and catalyst-free conditions at room temperature in open air. The 2-iminothiazolines are found to exhibit moderate activity against both the representative Gram positive and Gram negative bacteria, suggesting possible scope of using them as antimicrobials. Additionally Suzuki cross-coupling of 5-bromo-2-iminothiazolines with organoboronic acids produced fully substituted 5-aryl-2-iminothiazolines in good yield.

Mild and Expeditious Synthesis of Sulfenyl Enaminones of l-α-Amino Esters and Aryl/Alkyl Amines through NCS-Mediated Sulfenylation.

Sulfenylation or selenylation of enaminones of l-α-amino esters requires mild reaction conditions due to the presence of a racemization-prone chiral center and reactive side chains. An N-chlorosuccinimide (NCS)-mediated methodology has been developed for rapid sulfenylation of enaminones of l-α-amino esters and aryl/alkyl amines at room temperature in open air under metal-free conditions. Enaminones of l-α-amino esters bearing aliphatic, aromatic, and heterocyclic side chains react efficiently with diverse aryl/alkyl/heteroaryl thiols (R1SH) in the presence of NCS to afford a library of biologically important sulfenyl enaminones in good-to-excellent yields (71–90%). Under similar reaction conditions, the enaminones also react with benzeneselenol to produce selenyl enaminones in good yield (73–83%). The NCS-mediated pathway generates sulfenyl chloride (R1SCl) as an intermediate which leads to rapid sulfenylation of enaminones through cross-dehydrogenative coupling (CDC) under mild reaction conditions.

Seven Decades of Coastal Change at Barter Island, Alaska: Exploring the Importance of Waves and Temperature on Erosion of Coastal Permafrost Bluffs

Observational data of coastal change over much of the Arctic are limited largely due to its immensity, remoteness, harsh environment, and restricted periods of sunlight and ice-free conditions. Barter Island, Alaska, is one of the few locations where an extensive, observational dataset exists, which enables a detailed assessment of the trends and patterns of coastal change over decadal to annual time scales. Coastal bluff and shoreline positions were delineated from maps, aerial photographs, and satellite imagery acquired between 1947 and 2020, and at a nearly annual rate since 2004. Rates and patterns of shoreline and bluff change varied widely over the observational period. Shorelines showed a consistent trend of southerly erosion and westerly extension of the western termini of Barter Island and Bernard Spit, which has accelerated since at least 2000. The 3.2 km long stretch of ocean-exposed coastal permafrost bluffs retreated on average 114 m and at a maximum of 163 m at an average long-term rate (70 year) of 1.6 ± 0.1 m/yr. The long-term retreat rate was punctuated by individual years with retreat rates up to four times higher (6.6 ± 1.9 m/yr; 2012–2013) and both long-term (multidecadal) and short-term (annual to semiannual) rates showed a steady increase in retreat rates through time, with consistently high rates since 2015. A best-fit polynomial trend indicated acceleration in retreat rates that was independent of the large spatial and temporal variations observed on an annual basis. Rates and patterns of bluff retreat were correlated to incident wave energy and air and water temperatures. Wave energy was found to be the dominant driver of bluff retreat, followed by sea surface temperatures and warming air temperatures that are considered proxies for evaluating thermo-erosion and denudation. Normalized anomalies of cumulative wave energy, duration of open water, and air and sea temperature showed at least three distinct phases since 1979: a negative phase prior to 1987, a mixed phase between 1987 and the early to late 2000s, followed by a positive phase extending to 2020. The duration of the open-water season has tripled since 1979, increasing from approximately 40 to 140 days. Acceleration in retreat rates at Barter Island may be related to increases in both thermodenudation, associated with increasing air temperature, and the number of niche-forming and block-collapsing episodes associated with higher air and water temperature, more frequent storms, and longer ice-free conditions in the Beaufort Sea.

Retraction Note: Mountain atmospheric characteristics based on 5G big data and Yunnan minority pattern design

With the constantly updated new technologies and application software and the 5G big data era that is gradually moving to the market, big data as a modern technological resource has gradually developed in terms of conversion conditions and methods, and it is more convenient to transform from abstraction to reality, which is a mountainous atmosphere detection zone. There are new opportunities and challenges. Therefore, in the context of 5G big data, discussing how to improve the ability of mountain atmospheric observation has certain theoretical value and practical significance. The atmospheric characteristics of the mountain refer to the heat (warming) generated by the uplifted land. The altitude of the mountain/plateau changes the heat distribution pattern of the mountain and its surrounding area, and raises the internal temperature of the mountain to be higher than the surrounding open air temperature at the same altitude. Horizontal pattern is observed, thus forming a vertical pattern in which the inside of the natural area is higher than the outside. The quantification of mountain effects is the key to solving the problem of no belts in vertical mountainous areas. The country must promote its legacy and make it widely known. A basic element of modern pattern design is the pattern design of Yunnan ethnic minorities, which is a medium for expressing cultural heritage. This part of the pattern design of ethnic minorities includes profound ancient cultural and esthetic characteristics, rich in national colors. Relying on the application of Yunnan ethnic minority folk art patterns in contemporary art design, it demonstrates leading the ethnic cultural personality decoration trend, promoting the diversification of contemporary design styles, fully reflecting the natural customs and human factors and other aspects, and discussing the Yunnan ethnic folk art pattern spiritual essence. Based on the actual demands of contemporary pattern design, analyzing the actual application of Yunnan ethnic and folk art patterns plays an important role in the development of the field of Chinese art design.

RETRACTED ARTICLE: Mountain atmospheric characteristics based on 5G big data and Yunnan minority pattern design

With the constantly updated new technologies and application software and the 5G big data era that is gradually moving to the market, big data as a modern technological resource has gradually developed in terms of conversion conditions and methods, and it is more convenient to transform from abstraction to reality, which is a mountainous atmosphere detection zone. There are new opportunities and challenges. Therefore, in the context of 5G big data, discussing how to improve the ability of mountain atmospheric observation has certain theoretical value and practical significance. The atmospheric characteristics of the mountain refer to the heat (warming) generated by the uplifted land. The altitude of the mountain/plateau changes the heat distribution pattern of the mountain and its surrounding area, and raises the internal temperature of the mountain to be higher than the surrounding open air temperature at the same altitude. Horizontal pattern is observed, thus forming a vertical pattern in which the inside of the natural area is higher than the outside. The quantification of mountain effects is the key to solving the problem of no belts in vertical mountainous areas. The country must promote its legacy and make it widely known. A basic element of modern pattern design is the pattern design of Yunnan ethnic minorities, which is a medium for expressing cultural heritage. This part of the pattern design of ethnic minorities includes profound ancient cultural and esthetic characteristics, rich in national colors. Relying on the application of Yunnan ethnic minority folk art patterns in contemporary art design, it demonstrates leading the ethnic cultural personality decoration trend, promoting the diversification of contemporary design styles, fully reflecting the natural customs and human factors and other aspects, and discussing the Yunnan ethnic folk art pattern spiritual essence. Based on the actual demands of contemporary pattern design, analyzing the actual application of Yunnan ethnic and folk art patterns plays an important role in the development of the field of Chinese art design.

Silver coated and filled carbon nanotubes: Synthesis, electrical and thermal properties, and iodine vapor sensing

Here we present a simple method to fill multiwalled carbon nanotubes (MWCNT) with silver. This method involves stirring of MWCTs in AgNO3 solution at room temperature in open air followed by heating in H2 atmosphere at 250 °C for two hours. Process also leads to small coating of Ag on the surface. We confirmed the presence of crystalline silver in both coating and filling in hybrid MWCNTs by high resolution transmission electron microscopy, energy dispersive X-ray spectroscopy and electron diffraction. After silver coating and filling, bulk thermal diffusivity and thermal conductivity of Ag hybrid MWCNTs were increased by 242% and 255%, respectively. Furthermore, current-voltage measurements using tuna probe in atomic force microscopy showed higher number of charge carriers in the Ag hybrid nanotubes compared to pristine MWCNTs which resulted in up to 173% increase in their electrical conductivity. The Ag hybrid MWCNT based sensor also showed rapid and reversible sensing for I2 vapors: bulk sensor film demonstrated sensing response of 45% in just ~60 s at room temperature. However, the sensor recovery was slower: after removal of I2 vapors source, the recovery took 400 s and required heating at 100 °C in air. Response and recovery of sensor film was maintained after repeated cycles of exposure. Finally, the Ag hybrid MWCNTs film displayed high stability and selectivity for I2 vapors.

Rapid large-scale synthesis of highly emissive solid-state metal halide perovskite quantum dots across the full visible spectrum

The practical applications of solid-state inorganic CsPbX3 perovskite quantum dots (PQDs) have been restricted by their poor stability. Herein, we report an efficient large-scale synthesis of solid-state CsPbX3 PQDs across the full visible spectra using 3-Aminopropyltrimethoxysilane as ligands at room temperature in open air. The obtained green CsPbBr3 solids display outstanding optical performance with high color purity of 90% and photoluminescence quantum yield of 69.2%. Thanks to the protection of silica coating, the solid-state product shows much higher thermal stability, photo stability and long-term stability than that of naked CsPbBr3 QDs. The blue CsPb(Br/Cl)3 and yellow or red CsPb(Br/I)3 PQDs solids can be simply obtained via using alkali metal halide aqueous solution as additives. The white LED fabricated by combining the obtained green CsPbBr3 QDs solid powders and commercial red K2SiF6: Mn4+ phosphor with a blue LED chip displays high luminous efficiency of 70.47 lm/W and the color gamut can cover over 129.4% of the National Television System Committee standard.

A Novel Lightweight Phase-changing Cooling Roof Tile

Roof tiles are the most common roof coverings in Indian buildings, especially in traditional residential buildings. Given the important role of roofing characteristics in building energy efficiency and indoor thermal comfort conditions, innovative solutions to improve the thermal energy performance of this diffused roofing element have become a key research issue. In this perspective, cool roofing applications represent an effective solution to this objective. The present work deals with the analysis of innovative cooling roof tile manufactured using a combination of Metakaolin with different percentages, EPS, sodium silicate and coating material. The experimental work was carried out during day and night. The thermal performance of cool roof tiles were assessed in terms of the open-air temperature compared to the thermal performance of ordinary roofing tile. The report discovered that using revolutionary cool roofs greatly increased thermal comfort during the daytime, and preserved thermal comfort during the night. The innovative cool roof tile is cheaper, easier to implement, and less expensive compared to other roofing technologies. The study revealed that the roof's exterior and interior surface temperature reduced about 8°C and 12°C, respectively during day time, while roof's exterior and interior surface temperature maintain atmospheric temperature during night time. The compressive and transverse breaking strength was increasing about 9.1% and 39.6%.

Effect of relative humidity on hydrogen peroxide production in water droplets.

Mist is generated by ultrasonic cavitation of water (Fisher Biograde, pH5.5-6.5) at room temperature (20-25°C) in open air with nearly constant temperature (22-25°C) but varying relative humidity (RH; 24-52%) over the course of many months. Water droplets in the mist are initially about 7 μm in diameter at about 50% RH. They are collected, and the concentration of hydrogen peroxide (H2O2) is measured using commercial peroxide test strips and by bromothymol blue oxidation. The quantification method is based on the Fenton chemistry of dye degradation to determine the oxidation capacity of water samples that have been treated by ultrasonication. It is found that the hydrogen peroxide concentration varies nearly linearly with RH over the range studied, reaching a low of 2 parts per million (ppm) at 24% RH and a high of 6ppm at 52% RH. Some possible public health implications concerning the transmission of respiratory viral infections are suggested for this threefold change in H2O2 concentration with RH.

Solar drying of residue from Brazil nut processing

Abstract Brazil nuts are often used for direct consumption or in the preparation process of water-soluble extract. After obtaining the water-soluble extract, a large amount of Brazil nut residues with good sensory characteristics are generated. Thus, this study aimed to dry Brazil nut processing residues in layers with different thicknesses in a direct solar dryer as well as by direct exposure to the sun, in order to fit different mathematical models to the experimental data of drying kinetics, and calculate the drying rates and effective diffusivity. The drying procedures began at 9 a.m. on a concrete base, for samples dried by direct exposure to the sun, and in a solar dryer constructed with expanded polystyrene foam zinc plated and a glass cover. The mass loss of the samples was monitored by weighing at regular times until the hygroscopic equilibrium was obtained. The direct solar dryer had temperatures about 80% higher than those recorded in the open environmental air temperature. Drying rates were higher in dehydrations performed in the solar dryer compared to the drying by exposure to the sun. The Midilli model was selected as the most adequate for predicting the drying of the samples under all experimental conditions, showing coefficients of determination above 0.99. The effective diffusion coefficients of moisture were higher in samples dehydrated in the solar dryer when compared to those dried by exposure to the sun. Regarding the research conducted under the experimental conditions of this study, the performance of the solar dryer to dry Brazil nut processing residues was satisfactory.

Visible-Light-Driven Photocatalyst- and Additive-Free Cross-Coupling of β-Ketothioamides with α-Diazo 1,3-Diketones: Access to Highly Functionalized Thiazolines.

A photocatalyst- and additive-free, visible-light-mediated chemoselective domino protocol was devised to access fully substituted thiazoline derivatives from β-ketothioamides and α-diazo 1,3-diketones at moderate temperature in open air. The reaction proceeds through in situ generation of electrophilic carbenes from α-diazo 1,3-diketones by a low-energy blue LED (448 nm), which undergoes selective coupling with nucleophilic β-ketothioamides to give thiazolines by successive formation of C-S and C-N bonds in one stretch. Notably, the benign and clean conditions, operational simplicity, sustainability, 100 % carbon economy, high yields, and wide functional-group tolerance are further attributes of the strategy. A mechanistic rationale for this cascade reaction sequence is well supported by control experiments.

Geospatial Opinion on Unusual Locust Swarm Invasions during Amphan Cyclone

The desert locust, Schistocerca gregaria Forsk. (Orthoptera: Acrididae) is a peculiar insect that exhibits density-dependent phase polyphenism. Gregarious phase enables desert locust to form a large groups and mass migrations during which significant crop loss and food security issues may occur. Currently, the most recent upsurge of desert locust is prevailing across Eastern Africa and Southwestern Asia. Usually desert locusts are restricted to regions like semi-arid and arid regions. A super cyclonic storm, namely Amphan originated during May 2020, in the Bay of Bengal of North Indian Ocean has influenced numerous swarms to migrate from the Thar desert region to other parts of India. In this research, satellite data were used to investigate the reasons for this sudden swarm migration. The results that revealed the wind jets passing above the Thar desert region have integrated with the cyclogenesis of Amphan and led to the formation of conduits. The favorable conditions in the conduits include the open sky conditions, air temperature and fresh vegetation availability. Moreover, the wind settings in the conduits have enabled the swarm migrate to follow the downwind facing the sunrays during early mornings for an easy and successful take-off. It is observed that during the take-off session the wind speed at 850 hPa pressure level is mostly double than that of surface wind in both the conduits.