Multimode Self‐Oscillating Vesicle Transformers

Engineering synthetic materials that mimic the complex rhythmic oscillatory behavior of living cells is a fundamental challenge in science and technology. Up to now, the reported synthetic model system still cannot compete with nature in oscillatory modes and amplitudes. Presented here is a novel alternating copolymer vesicle that exhibits drastic and multimode shape oscillations in real time, which are controlled by polymer concentrations and driven by the Belousov—Zhabotinsky oscillatory reaction, including swelling/deswelling, twisting/detwisting, stretching/shrinking, fusion/fission, and multiple division. Some of them, especially the fission oscillation, have not been observed before. In addition, the oscillation magnitude with regard to diameter is much larger than that of previously reported self‐oscillating vesicles. Such a self‐oscillating vesicle transformer would extend the complexity and capacity of membrane deformations in synthetic systems, approaching those of natural cells.     

Research Progress in the Field of Adsorption and Catalytic Degradation of Sewage by Hydrotalcite‐Derived Materials

With the rapid development of industry and agriculture and the greatly improved living conditions, the resultant gradually deteriorated environments threaten the human beings. Refractory or even toxic pollutants, which are from different industries such as printing and dyeing, pesticides, chemicals, petrochemicals, plastics and rubber, seriously threat the ecosystems and human health. Having the advantages of flexible composition, unique structure, high stability, memory effect, easy preparation and low cost, hydrotalcite compounds have a great potential in sewage degradation and environmental protection. This study focuses on the adsorption and catalytic properties (such as photocatalysis, electrocatalysis and photoelectrocatalysis) of hydrotalcite‐derived materials for treating organic, inorganic and heavy metal ion sewage. The types of adsorption and catalysis, and the effects of various influencing factors on the degradation efficiency were discussed as well.     

Machine-Learning Adsorption on Binary Alloy Surfaces for Catalyst Screening

Over the last few years, machine learning is gradually becoming an essential approach for the investigation of heterogeneous catalysis. As one of the important catalysts, binary alloys have attracted extensive attention for the screening of bifunctional catalysts. Here we present a holistic framework for machine learning approach to rapidly predict adsorption energies on the surfaces of metals and binary alloys. We evaluate different machine-learning methods to understand their applicability to the problem and combine a tree-ensemble method with a compressed-sensing method to construct decision trees for about 60000 adsorption data. Compared to linear scaling relations, our approach enables to make more accurate predictions lowering predictive root-mean-square error by a factor of two and more general to predict adsorption energies of various adsorbates on thousands of binary alloys surfaces, thus paving the way for the discovery of novel bimetallic catalysts.     

A novel heterogeneous Co(II)-Fenton-like catalyst for efficient photodegradation by visible light over extended pH

Science China Chemistry - A novel CoII-Fenton-like heterogeneous catalyst, (H3O)2[CoII(phen)(H2O)2]2[MoVI5O15(PO4)2]·4H2O (phen=1,10-phenanthroline, C12N2H8) (1), is synthesized and utilized...     

Through-space charge transfer blue polymers containing acridan donor and oxygen-bridged triphenylboron acceptor for highly efficient solution-processed organic light-emitting diodes

Three kinds of through-space charge transfer(TSCT) blue polymers containing non-conjugated polystyrene backbone together with spatially-separated acridan donor and oxygen-bridged triphenylboron acceptors having different substituents of tert-butyl,hydrogen and fluorine are designed and synthesized. The designed TSCT blue polymers possess photoluminescence quantum yields up to 70% in solid-state film, single-triplet energy splitting below 0.1 eV, and typical thermally activated delayed fluorescence(TADF) effect. Meanwhile, the resulting polymers exhibit aggregation-induced emission(AIE) effect with emission intensity increased by up to ～27 folds from solution to aggregation state. By changing the substituent of acceptors to tune the charge transfer strength, blue emission with peaks from 444 to 480 nm can be realized for the resulting polymers.Solution-processed organic light-emitting diodes based on the polymers exhibit excellent device performance with Commission Internationale de L'Eclairage(CIE) coordinates of(0.16, 0.27), together with the maximum luminous efficiency of 30.7 cd A~(-1) and maximum external quantum efficiency of 15.0%, which is the best device efficiency for blue TADF polymers.     

Coupled Electrical Conduction in Coordination Polymers: From Electrons/Ions to Mixed Charge Carriers

The coupled transport of ions and electrons is of great potential for next‐generation sensors, energy storage and conversion devices, optoelectronics, etc. Coordination polymers (CPs) intrinsically have both transport pathways for electrons and ions, however, the practical conductivities are usually low. In recent years, significant advances have been made in electronic or ionic conductive coordination polymers, which also results in progress in mixed ionic‐electronic conductive coordination polymers. Here we start from electronic and ionic conductive CPs to mixed ionic‐electronic conductive CPs. Recent advances in the design of mixed ionic‐electronic conductive CPs are summarized. In addition, devices based on mixed conduction are selected.     

Skin Friction Reduction of Hypersonic Body by Supersonic Layer

Fluid Dynamics - Both numerical methods and wind tunnel tests were used to reduce skin friction for a hypersonic body. A hypersonic cone was tested under three different free-stream flow...     

Numerical and Experimental Investigation of Liquid Residue in 90° Bend Microchannel Based on Gas–Liquid Two-Phase Flow

The microfluidic chip for nucleic acid detection in vitro is an essential application of microfluidic technology to the process of in vitro diagnosis. The 90° bend microchannels in chip designed for facilitating assay reagent delivery may cause reagent residues and cast mutual contamination between detection reagents, which significantly affects the detection accuracy. In this paper, a two-dimensional gas–liquid two-phase flow model is constructed to simulate the liquid residue phenomenon. Using the results of simulation, the residual liquid generation can be observed and the area of residual liquid can be obtained. The accuracy of the numerical simulation is verified by comparison with the experimental results. The effects of the fillet radius R, the diameter ratio d₁/d₂ of the vertical to horizontal sections, the flow velocity v, and the surface roughness R_a on the residual amount are studied. We find that the fillet radius is inversely proportional to the residual amount within the range v = 20–100 mm/s and there is almost no liquid residue in the channel when the radius increases to R = 1 mm. When the channel diameter ratio d₁/d₂ increases, the liquid residual amount also increases by approximately 98%. The increased surface roughness R_a significantly increases the residual amount. The results of this study provide a reference for the optimal design of microchannels on chips.

     

Study on wave dispersion characteristics of piezoelectric sandwich nanoplates considering surface effects

In this study, the wave propagation properties of piezoelectric sandwich nanoplates deposited on an orthotropic viscoelastic foundation are analyzed by considering the surface effects (SEs). The nanoplates are composed of a composite layer reinforced by graphene and two piezoelectric surface layers. Utilizing the modified Halpin-Tsai model, the material parameters of composite layers are obtained. The displacement field is determined by the sinusoidal shear deformation theory (SSDT). The Euler-Lagrange equation is derived by employing Hamilton’s principle and the constitutive equations of piezoelectric layers considering the SEs. Subsequently, the nonlocal strain gradient theory (NSGT) is used to obtain the equations of motion. Next, the effects of scale parameters, graphene distribution, orthotropic viscoelastic foundation, and SEs on the propagation behavior are numerically examined. The results reveal that the wave frequency is a periodic function of the orthotropic angle. Furthermore, the wave frequency increases with the increase in the SEs.

     

八信道高温超导多路器的实验研究

文中首先分析八信道高温超导多路器设计的方案,以及实现八信道高温超导多路器的技术;给出了用MgO基片为衬底,YBCO超导膜制备的高温超导滤波器设计仿真曲线及实际测试曲线;并对多路器所用制冷器的制冷量进行了计算;最后给出八信道高温超导多路器的实际测试曲线。