Energy storage property of a dielectric is closely tied with its nanostructure. In this study, we aimed to achieve a deep understanding of this relationship in high energy density ferroelectric ceramic films, by probi...
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We report high-pressure investigations of the mixed-valent perovskite Cs2SbBr6, in which Sb3+ and Sb5+ cations coexist, and two types of distorted SbBr6 octahedra are arranged without connectivity, forming a zero-dime...
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Magicity, or shell closure, plays an important role in our understanding of complex nuclear phenomena. In this work, we employ one of the state-of-the-art density functional theories, the deformed relativistic Hartree...
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China is experiencing accelerated urbanisation,with a large number of people moving from rural to urban areas[1].It has resulted in large losses in the net primary production(NPP),biodiversity and carbon stocks and an...
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China is experiencing accelerated urbanisation,with a large number of people moving from rural to urban areas[1].It has resulted in large losses in the net primary production(NPP),biodiversity and carbon stocks and an increase in environmental pollution and CO_(2)emissions[2–4].In 2015,196 countries signed the Paris Agreement and committed to setting long-term goals to jointly manage climate change and reduce their individual emissions,aiming to control the increase in global average temperature from the pre-industrial level to below 2℃and to curtail the temperature rise within 1.5℃till the end of the 21st century[5].China is bolstering its efforts to achieve the climate change mitigation goals and has announced a plan for achieving carbon neutrality by 2060[6].The carbon neutrality goal poses a challenge to the current policies promoting rapid urbanisation across China.
Reverse osmosis (RO) has been recognized as a reliable technique for wastewater reclamation. To enhance its rejection of trace organic contaminants (TrOCs), a novel strategy was proposed to improve reverse osmosis (RO...
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By adjusting the fluorine content and the molar ratio of 4,4'-dicyclohexylmethane diisocyanate (HMDI) to isophthalaldehyde (IPAL), a novel fluorinated polysiloxane/polyurea (FPUI) with an optimized dual-healing ne...
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By adjusting the fluorine content and the molar ratio of 4,4'-dicyclohexylmethane diisocyanate (HMDI) to isophthalaldehyde (IPAL), a novel fluorinated polysiloxane/polyurea (FPUI) with an optimized dual-healing network of hydrogen and imine bonds is synthesized. Using FPUI as a low-surface-energy matrix and incorporating nano-SiO
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via spraying, a biomimetic fluorinated polysiloxane/polyurea-silica (FPUS) anti-icing coating is developed, achieving durable anti-icing and de-icing performance. FPUS demonstrates complete self-healing within 15 min at room temperature, with tensile strength, elongation at break, and shear strength of 1.43 MPa, 159.32%, and 1.14 MPa, respectively. Water droplets on FPUS-coated surfaces (glass, carbon steel, plastic, and rubber) exhibit significantly longer freezing times compared to uncoated substrates. For instance, on uncoated glass, water freezes in 27 s, whereas on FPUS-coated glass, freezing is delayed to 619 s. Additionally, ice adhesion strength on uncoated glass is 364.16 kPa but was drastically reduced to 23.25 kPa on FPUS-coated glass. Even after 10 freeze-thaw cycles, the adhesion strength remains stable, increasing only slightly to 26.65 kPa. Beyond its anti-icing capabilities, FPUS also exhibited self-cleaning, antibacterial, and anti-corrosion properties. These features make it a promising candidate for protecting outdoor infrastructure and engineering equipment, such as wind turbine blades, photovoltaic panels, power transmission lines, aircraft, and offshore oil platforms.
Historical documents provide evidence for regional droughts preceding the political turmoil and fall of Beijing in 1644 CE,when more than 20 million people died in northern China during the late Ming famine ***,the ro...
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Historical documents provide evidence for regional droughts preceding the political turmoil and fall of Beijing in 1644 CE,when more than 20 million people died in northern China during the late Ming famine ***,the role climate and environmental changes may have played in this pivotal event in Chinese history remains ***,we provide tree-ring evidence of persistent megadroughts from1576 to 1593 CE and from 1628 to 1644 CE in northern China,which coincided with exceptionally cold summers just before the fall of *** analysis reveals that these regional hydroclimatic extremes are part of a series of megadroughts along the Pacific Rim,which not only impacted the ecology and society of monsoonal northern China,but likely also exacerbated external geopolitical and economic *** finding is corroborated by last millennium reanalysis data and numerical climate model simulations revealing internally driven Pacific sea surface temperature variations and the predominance of decadal scale La Ni?a-like conditions to be responsible for precipitation decreases over northern China,as well as extensive monsoon regions in the *** teleconnection patterns provide a mechanistic explanation for reoccurring drought spells during the late Ming Dynasty and the environmental framework fostering the fall of Beijing in 1644 CE,and the subsequent demise of the Ming Dynasty.
The microscopic framework of time-dependent covariant density functional theory is applied to a systematic study of ternary quasifission in collisions of pairs of 238U nuclei. It is shown that the inclusion of octupol...
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The microstructural characteristics, elemental distribution law and microscopic formation mechanism of the burning products of TA15 titanium alloy were investigated by friction oxygen concentration method, associated ...
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The microstructural characteristics, elemental distribution law and microscopic formation mechanism of the burning products of TA15 titanium alloy were investigated by friction oxygen concentration method, associated with in situ observation, X-ray diffraction(XRD),scanning electron microscopy(SEM) and energy-dispersive spectroscopy(EDS) analyses, providing the thoughts to improve fireproof property. The results show that, when the friction contact pressure(p) is 0.20 MPa and oxygen concentration of premixed air flow(c) is 60 vol%, TA15 titanium alloy produces violent sparks and presents dazzling white light during combustion. The generated products after burning are mainly TiOand small amount of AlOoxides. Four distinct zones form from the combustion surface to the alloy matrix, and they are in the sequence of combustion zone, fusion zone, heat-affected zone and transition zone. Further, combustion zone is composed of TiOand A1203 compounds, containing obvious cracks. In the fusion zone, discontinuous oxygenrich Al-based solid solution forms, and the elemental distribution has strong volatility. In the heat-affected zone,there are abundant of Ti-based solid solution and small amount of Al-and Mo-based solid solution. Transition zone is made of lamellar structure. Two technical approaches are given to prevent oxygen diffusion inside the reaction zone and reaction-affected zone. On the one hand,the content of Al is designed as the upper limit of alloy composition; on the other hand, fireproof coatings are deposited on the surface of the alloy.
Nitrous acid (HONO) is a key precursor of the hydroxyl radicals (OH) and has a significant impact on air quality. Nowadays, the source of HONO is still controversial due to its complex formation mechanisms, which is w...
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