Spontaneous coagulation casting（SCC） is a novel in-situ ceramic forming method,not only universal for various ceramics but also working well at room temperature in air.Here presents the finding of ...SCC,involving an anion dispersant which acts as both dispersing and coagulating agent.Then,the difference between SCC and other in-situ coagulation methods in principle was elucidated.In SCC,particles participate in the formation of organic network which originates from hydrophobic interaction and hydrogen bonding among the dispersant molecular chains.The ceramic gel formed by SCC is a physical gel and possesses low density which is conducive to water transportation and stress relaxation during drying.In contrast,the one by conventional gelcasting is a chemical gel in which particles are fixed by a dense organic network.Based on the hydrophobic interaction,this review focuses on the design and synthesis of a series of SCC agents to meet the demand of forming dense and porous ceramics from particles with different sizes.That is,an anion dispersant is hydrophobically modified by a surfactant with a short or long chain.The obtained two agents are used for preparation of dense and porous ceramics,respectively.Progress of key technologies in this area including ceramic joining without interface,construction of grain orientation,drying,preparation of dense ceramics and porous ceramics,by SCC is summarized.Typically,alumina disc with a diameter up to 1010 nm and alumina parts with complicated shape such as dome and guide are shown.Future development of SCC is also proposed to enable SCC tobe a more universal forming technology for advanced ceramics with a large and/or complicated dimension.
Dormant
Bacillales
and
Clostridiales
spores begin to grow when small molecules (germinants) trigger germination, potentially leading to food spoilage or disease. Germination-specific proteins sense ...germinants, transport small molecules, and hydrolyze specific bonds in cortex peptidoglycan and specific proteins. Major events in germination include (
a
) germinant sensing; (
b
) commitment to germinate; (
c
) release of spores' depot of dipicolinic acid (DPA); (
d
) hydrolysis of spores' peptidoglycan cortex; and (
e
) spore core swelling and water uptake, cell wall peptidoglycan remodeling, and restoration of core protein and inner spore membrane lipid mobility. Germination is similar between
Bacillales
and
Clostridiales
, but some species differ in how germinants are sensed and how cortex hydrolysis and DPA release are triggered. Despite detailed knowledge of the proteins and signal transduction pathways involved in germination, precisely what some germination proteins do and how they do it remain unclear.
Display omitted
•MBSR is used for the remediation of two black and stinking urban rivers.•Water quality of the rivers is significantly improved after MBSR treatment.•Aerobic microbes responsible for ...pollutant removal are stimulated.•The ecological mechanism of MBSR restoration is elucidated.
Microbes play important roles during river remediation and the interaction mechanism illustration between microorganisms and sewage is of great significance to improve restoration technology. In this study, micro-nano bubble and submerged resin floating bed composite technology (MBSR) was firstly used to restore two black and stinking urban rivers. After restoration, the water pollution indices such as dissolved oxygen (DO), ammonia nitrogen (NH4+-N), total phosphorous (TP), chemical oxygen demand (CODCr), water clarity, and the number of facial coliform were significantly improved. Microbial community composition and relative abundance both varied and more aerobic microbes emerged after remediation. The microbial changes showed correlation with DO, NH4+-N, TP and CODCr of the rivers. In summary, the MBSR treatment improved the physiochemical properties of the two black and stinking urban rivers probably through oxygen enrichment of micro-nano bubble and adsorption of submerged resin floating bed, which thereby stimulated functional microbes to degrade pollutants.
A
2
B
2
O
7
system compounds, which usually present three phase structures mainly based on the ionic radius ratios of
r
A
and
r
B
(
r
A
/
r
B
), have been studied for potential applications in many ...fields, such as thermal barrier coatings, luminescence powders, fast-ion conductors, photocatalysts, and matrices for immobilization of highly active radionuclides. Since 2005, La
2
Hf
2
O
7
was fabricated into transparent ceramics and much more attentions were paid on A
2
B
2
O
7
transparent ceramics for new applications. In this review, the development of A
2
B
2
O
7
system transparent ceramics was described. The structure characteristics, powder synthesis method, and sintering techniques of the final A
2
B
2
O
7
transparent ceramics were summarized. After that, the mostly reported A
2
Hf
2
O
7
, A
2
Zr
2
O
7
, and A
2
Ti
2
O
7
system transparent ceramics were systematically introduced. The potential application fields and future development trends were also discussed, focusing on scintillators, optical elements, and other luminescent materials
The slow development of photoelectrochemical (PEC) water splitting mainly results from the inefficient separation and transfer of photogenerated carriers. Herein, we fabricated a core-shell ...nanostructure by loading MgAl-layered double hydroxide (MgAl-LDH) nanofilms on the surface of TiO2 nanorods with a simple dip-coating method. The PEC performance was adjusted by controlling the immersion time, and TiO2/MgAl-LDH photoanode with an immersion time of 8 h achieved an optimal photocurrent density of 1.16 mA cm−2, which is 116 times that of TiO2. The improved interfacial charge transfer and reduced recombination loss of photogenerated electron-hole pairs account for the excellent performance.
Display omitted
•The core-shell nanostructure was fabricated by a simple dip-coating method.•The dense and smooth MgAl-LDH nanofilms endow the enhanced performance of TiO2.•An current density of 1.16 mA/cm2 was achieved by the TiO2/MgAl-LDH photoanode.
The utilization of an appropriate collector or surfactant is crucial for the beneficiation of low-rank coal. However, in previous studies, the selection of surfactants was primarily based on ...flotation procedures, which hinders the understanding of the interaction mechanism between surfactant groups and oxygen-containing functional groups at the surface of low-rank coal. In this study, we investigate the flotation of low-rank coal in the presence of a composite collector by using a combined theoretical and experimental approach. The maximum flotation mass recovery achieved was 82.89% using a 3:1 mixture of dodecane and castor oil acid. Fourier-transform infrared and X-ray photoelectron spectroscopic analyses showed that castor oil acid was effectively adsorbed onto the surface of low-rank coal, enhancing the hydrophobicity of the coal. In addition, the diffusion coefficient of water molecules in the water-composite collector-coal system was greater than that in the dodecane system. Moreover, due to the presence of castor oil acid in the flotation process, the adsorption distance of dodecane and low-rank coal became shorter. Molecular dynamics simulations revealed that the diffusion and interaction of surfactant molecules at the interface of low-rank coal particles and water was enhanced because the adsorption of the dodecane-castor oil acid mixture is primarily controlled by hydrogen bonds and electrostatic attraction. Based on these results, a better surfactant for flotation of low-rank coal is also proposed.
Among the many materials investigated for next-generation photovoltaic cells, organic-inorganic lead halide perovskites have demonstrated great potential thanks to their high power conversion ...efficiency and solution processability. Within a short period of about 5 years, the efficiency of solar cells based on these materials has increased dramatically from 3.8 to over 20%. Despite the tremendous progress in device performance, much less is known about the underlying photophysics involving charge-orbital-lattice interactions and the role of the organic molecules in this hybrid material remains poorly understood. Here, we report a giant photostrictive response, that is, light-induced lattice change, of >1,200 p.p.m. in methylammonium lead iodide, which could be the key to understand its superior optical properties. The strong photon-lattice coupling also opens up the possibility of employing these materials in wireless opto-mechanical devices.
Here, we present a physiologically relevant model of the human pulmonary alveoli. This alveolar lung-on-a-chip platform is composed of a three-dimensional porous hydrogel made of gelatin methacryloyl ...with an inverse opal structure, bonded to a compartmentalized polydimethylsiloxane chip. The inverse opal hydrogel structure features well-defined, interconnected pores with high similarity to human alveolar sacs. By populating the sacs with primary human alveolar epithelial cells, functional epithelial monolayers are readily formed. Cyclic strain is integrated into the device to allow biomimetic breathing events of the alveolar lung, which, in addition, makes it possible to investigate pathological effects such as those incurred by cigarette smoking and severe acute respiratory syndrome coronavirus 2 pseudoviral infection. Our study demonstrates a unique method for reconstitution of the functional human pulmonary alveoli in vitro, which is anticipated to pave the way for investigating relevant physiological and pathological events in the human distal lung.
The Middle-Lower Yangtze River Valley Metallogenic Belt (MLYB) is one of the most important metallogenic belts in eastern China, and contains many important porphyry deposits. These deposits include ...the Tongshankou Cu-Mo, Jiguanzui Cu-Au, Chengmengshan Cu-Mo, Wushan Cu-Mo, Fengshandong Cu-Au, Dingjiashan Cu, Yangjishan Au, Shaxi Cu-Au, Dongguashan Cu-Au, Shujiadian Cu and Anjishan Cu deposits, etc. In this review, we summarize the geological characteristics (including the stratigraphy, structure, ore-bearing porphyry types, vein characteristics and wall rock alteration), metallogenic ages and petro-geochemistry of representative porphyry deposits in the MLYB. We conclude that porphyritic magmatism and metallogeny have occurred in three stages. The Early (ca. 149–135 Ma) and Late (ca. 123–105 Ma) stages comprise mainly porphyry-skarn mineralization, whereas the Middle (ca. 133–125 Ma) stage comprises porphyry mineralization. Ore-bearing porphyries in the MLYB are the high-K calc-alkaline to calc-alkaline series, with the majority possess adakitic geochemical signature. The ore-bearing porphyries with adakitic signature may have originated from magma mixing, produced by the delamination of enriched lithospheric mantle and partial melting of the thickened lower crust. The enriched mantle-derived mafic melts component are very important for generating fertile magma, and the δ34S and δ18O values suggest that ore-forming materials were magma-derived. Compared with porphyry deposits in typical magmatic arc settings, porphyry deposits in the MLYB do not contain advanced argillic lithocaps or high- to intermediate-sulfidation systems, and the magmatic- and ore-forming material sources are also very different.
Display omitted
•The porphyritic magmatism and associated mineralization in the Middle-Lower Yangtze River Valley Metallogenic Belt could be subdivided into three stages: 149–135 Ma, 133–125 Ma and 123–105 Ma.•The ore-bearing porphyries may produce by the mixing magma generated from the delamination of enriched lithospheric mantle and partial melting of the thickened lower crust.•The enriched mantle-derived mafic magma component plays a important role for the generating fertile magma.•Compare with porphyry deposits generated in typical magmatic arcs in detail.
PDF
