Substrate‐supported metal–organic frameworks (MOFs) films are desired to realize their potential in practical applications. Herein, a novel substrate‐seeding secondary‐growth strategy is developed to ...prepare composites of uniform MOFs films on aerogel walls. Briefly, the organic ligand is “pre‐seeded” onto the aerogel walls, and then a small amount of metal‐ion solution is sprayed onto the prepared aerogel. The sprayed solution diffuses along the aerogel walls to form a continuous thin layer, which confines the nucleation reaction, promoting the formation of uniform MOFs films on the aerogel walls. The whole process is simple in operation, highly efficient, and eco‐friendly. The resulting hierarchical MOFs/aerogel composites have abundant accessible active sites and enable excellent mass transfer, which endows the composite with outstanding catalytic activity and stability in both liquid‐phase CO2 cycloaddition and electrochemical oxygen evolution reaction (OER) process.
Metal–organic framework (MOF) thin films are coated onto the walls of aerogel giving MOFs/aerogel composites. These have abundant accessible active sites and excellent mass transfer ability, and thus a relatively high catalytic activity and stability in the CO2 cycloaddition and oxygen evolution reaction (OER).
The use of formic acid (FA) to produce molecular H2 is a promising means of efficient energy storage in a fuel‐cell‐based hydrogen economy. To date, there has been a lack of heterogeneous catalyst ...systems that are sufficiently active, selective, and stable for clean H2 production by FA decomposition at room temperature. For the first time, we report that flexible pyridinic‐N‐doped carbon hybrids as support materials can significantly boost the efficiency of palladium nanoparticle for H2 generation; this is due to prominent surface electronic modulation. Under mild conditions, the optimized engineered Pd/CN0.25 catalyst exhibited high performance in both FA dehydrogenation (achieving almost full conversion, and a turnover frequency of 5530 h−1 at 25 °C) and the reversible process of CO2 hydrogenation into FA. This system can lead to a full carbon‐neutral energy cycle.
Pyridinic‐N‐tuned catalysis: An electron‐rich pyridinic‐N dopant modulates the electronic interactions between the active sites of palladium nanoparticles and the carbon support. Formic acid dehydrogenation at room temperature is significantly boosted by the pyridinic‐N‐doped palladium catalyst, presenting an efficient and reliable route to clean H2 generation and sustainable energy storage.
•Key contents and properties of algal suspension including cells and AOM are addressed.•MF and UF fouling by algal cells and AOM are compared, with cell growth discussed.•Control strategies via ...pretreating feedwater for algal fouling are reviewed.•Optimization of membrane properties and hydrodynamic conditions are provided.
Microalgae are ubiquitous in aquatic systems and are a highly diversified group of uni- and multicellular microorganisms. In low pressure-driven membrane systems, these cells and their secretions have a strong tendency to foul membranes and lead to a very low filtration efficiency. A significant amount of investigation on algal fouling of microfiltration (MF) and ultrafiltration (UF) membranes has been conducted in recent years. In this paper, recent knowledge of both MF and UF membrane fouling by microalgal suspensions, including the mechanisms and factors influencing algal fouling control strategies, is reviewed. The main components and properties of microalgae suspension are summarized. As algal cells and algogenic organic matter (AOM) are major foulants in microalgae suspension, their roles in algal fouling are compared and critically assessed. Based on the fouling mechanisms of these cells and AOM, strategies for mitigation of algal fouling are provided in detail, including pretreating feedwater, changing membrane properties, and enhancing hydrodynamic conditions. The breakup and growth of cells and their consequential influences on fouling receive special attention. Finally, useful directions for further work on MF and UF algal fouling are indicated.
A solar thermoelectric generator (STEG) that generates electricity from sunlight is expected to be a promising technology for harvesting and conversion of clean solar energy. The integration of a ...phase-change material (PCM) with the STEG even more enables engines to durably generate power in spite of solar radiation flux. However, its photothermal conversion and output electricity is still limited (<15 W/m2) by the PCM’s deficient thermal management performance, i.e., restricted thermal conductivity and nonuniform heat-transfer behavior under concentrated sunlight radiation. In this study, a biomimetic phase-change composite, with centrosymmetric and a multidirectionally aligned boron nitride network embedded in polyethylene glycol, is tailored for the STEG via a radial ice-template assembly and infiltration strategy, which behaves in a highly and multidirectionally thermoconductive way and enables a rapid transfer of heat flux and uniform temperature distribution with respect to even a spot-like heat source. As a consequence, a powerful STEG is tactfully designed via the integration of this high-thermal-management characteristic and maximum collection of solar beams, for durable and real-environment solar–thermal–electric conversion, with its photothermal energy conversion efficiency of up to 85.1% and a high peak power density of 40.28 W/m2.
Lonicerae japonicae flos (called Jinyinhua, JYH in Chinese), flowers or flower buds of
Lonicera japonica
Thunberg, is an extremely used traditional edible-medicinal herb. Pharmacological studies have ...already proved JYH ideal clinical therapeutic effects on inflammation and infectious diseases and prominent effects on multiple targets in vitro and in vivo, such as pro-inflammatory protein inducible nitric oxide synthase, toll-like receptor 4, interleukin-1 receptor. JYH and Lonicerae flos called Shanyinhua, SYH in Chinese, flowers or flower buds of
Lonicera hypoglauca
Miquel,
Lonicera confusa
De Candolle or
Lonicera macrantha
(D.Don) Spreng which belongs to the same family of JYH were once recorded as same herb in multiple versions of Chinese Pharmacopoeia (ChP). However, they were listed as two different herbs in 2005 Edition ChP, leading to endless controversy since they have close proximity on plant species, appearances and functions, together with traditional applications. In the past decades, there has no literature regarding to systematical comparison on the similarity concerning research achievements of the two herbs. This review comprehensively presents similarities and differences between JYH and SYH retrospectively, particularly proposing them the marked differences in botanies, phytochemistry and pharmacological activities which can be used as evidence of separate list of JYH and SYH. Furthermore, deficiencies on present studies have also been discussed so as to further research could use for reference.
with the development of new media technology and the popularity of mobile devices, the short video platform has become one of the standing applications in the public’s mobile phones, and the short ...video tool has added a new color to the development of video shooting technology while enriching the spiritual and cultural life of the public. In the era of new media convergence, short video shooting technology has become an indispensable part of video shooting, in view of this, this paper mainly focuses on the analysis and research of short video photography technology under the integration of computer editing in the new media era.
Confined microenvironments formed in heterogeneous catalysts have recently been recognized as equally important as catalytically active sites. Understanding the fundamentals of confined catalysis has ...become an important topic in heterogeneous catalysis. Well-defined 2D space between a catalyst surface and a 2D material overlayer provides an ideal microenvironment to explore the confined catalysis experimentally and theoretically. Using density functional theory calculations, we reveal that adsorption of atoms and molecules on a Pt(111) surface always has been weakened under monolayer graphene, which is attributed to the geometric constraint and confinement field in the 2D space between the graphene overlayer and the Pt(111) surface. A similar result has been found on Pt(110) and Pt(100) surfaces covered with graphene. The microenvironment created by coating a catalyst surface with 2D material overlayer can be used to modulate surface reactivity, which has been illustrated by optimizing oxygen reduction reaction activity on Pt(111) covered by various 2D materials. We demonstrate a concept of confined catalysis under 2D cover based on a weak van der Waals interaction between 2D material overlayers and underlying catalyst surfaces.
Many biological surfaces in both the plant and animal kingdom possess unusual structural features at the micro- and nanometre-scale that control their interaction with water and hence wettability. An ...intriguing example is provided by desert beetles, which use micrometre-sized patterns of hydrophobic and hydrophilic regions on their backs to capture water from humid air. As anyone who has admired spider webs adorned with dew drops will appreciate, spider silk is also capable of efficiently collecting water from air. Here we show that the water-collecting ability of the capture silk of the cribellate spider Uloborus walckenaerius is the result of a unique fibre structure that forms after wetting, with the 'wet-rebuilt' fibres characterized by periodic spindle-knots made of random nanofibrils and separated by joints made of aligned nanofibrils. These structural features result in a surface energy gradient between the spindle-knots and the joints and also in a difference in Laplace pressure, with both factors acting together to achieve continuous condensation and directional collection of water drops around spindle-knots. Submillimetre-sized liquid drops have been driven by surface energy gradients or a difference in Laplace pressure, but until now neither force on its own has been used to overcome the larger hysteresis effects that make the movement of micrometre-sized drops more difficult. By tapping into both driving forces, spider silk achieves this task. Inspired by this finding, we designed artificial fibres that mimic the structural features of silk and exhibit its directional water-collecting ability.
Dentists have used rapid prototyping (RP) techniques in the fields of oral maxillofacial surgery simulation and implantology. With new research emerging for molding materials and the forming process ...of RP techniques, this method is becoming more attractive in dental prosthesis fabrication; however, few researchers have published material on the RP technology of prosthesis pattern fabrication. This article reviews and discusses the application of RP techniques for prosthodontics including: (1) fabrication of wax pattern for the dental prosthesis, (2) dental (facial) prosthesis mold (shell) fabrication, (3) dental metal prosthesis fabrication, and (4) zirconia prosthesis fabrication. Many people could benefit from this new technology through various forms of dental prosthesis production. Traditional prosthodontic practices could also be changed by RP techniques in the near future.
Compared with other motors, the permanent magnet synchronous motor (PMSM) is small and occupies less space. At the same time, its weight is relatively light, so it is more in line with the ...development trend of hybrid electric vehicle (EV) drive motor lightweight miniaturization and has been widely used. This article studies a DSP-controlled PMSM control system for hybrid vehicles. Firstly, the motor drive control system is mainly controlled by DSP2812 chip. Then, a maximum torque current ratio control method was proposed to optimize the energy efficiency of hybrid vehicles based on PMSM. The longitudinal dynamic model of the moving hybrid vehicle was obtained by force analysis. Combined with the basic equation of PMSM and the transmission system of the hybrid vehicle, the mathematical model of PMSM-EV was established. The experimental results show that the maximum torque current ratio control method applied to hybrid vehicles can effectively reduce the loss, improve the efficiency and dynamic performance, and solve the endurance problem of hybrid vehicles to a certain extent. This advantage is significant in the dynamic acceleration and deceleration of hybrid vehicles.
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