Photocatalytic syngas synthesis from CO2 and H2O using ultrafine CeO2-decorated layered double hydroxide nanosheets under visible-light up to 600 nm

The rational design of photocatalyst that can effectively reduce CO₂ under visible light(l>400 nm),and simultaneously precise control of the products syngas(CO/H2)ratio is highly desirable for the Fischer-Tropsch reaction.In this work,we synthesized a series of CeO₂-decorated layered double hydroxides(LDHs,Ce-x)samples for photocatalytic CO₂ reduction.It was found that the selectivity and productivity of CO and H₂ from photoreduction of CO₂ in conjunction with Ru-complex as photosensitizer performed an obvious“volcano-like”trend,with the highest point at Ce-0.15 and the CO/H₂ ratio can be widely tunable from 1/7.7 to 1/1.3.Furthermore,compared with LDH,Ce-0.15 also drove photocatalytic CO₂ to syngas under 600 nm irradiation.It implied that an optimum amount of CeO₂ modifying LDH promoted the photoreduction of CO₂ to syngas.This report gives the way to fully utilize the rare earth elements and provides a promising route to enhance the photo-response ability and charge injection efficiency of LDH-based photocatalysts in the synthesis of syngas with a tunable ratio under visible light irradiation.     

Experimental and numerical simulation of lignite chemical looping gasification with phosphogypsum as oxygen carrier in a fluidized bed

Phosphogypsum (PG) is a solid waste produced in the wet process of producing phosphoric acid.Lignite is a kind of promising chemical raw material.However,the high sulfur of lignite limits the utilization of lig-nite as a resource.Based on fluidized bed experiments,the optimal reaction conditions for the production syngas by lignite chemical looping gasification (CLG) with PG as oxygen carrier were studied.The study found that the optimal reaction temperature should not exceed 1123 K;the mole ratio of water vapor to lignite should be about 0.2;the mole ratio of PG oxygen carrier to lignite should be about 0.6.Meanwhile,commercial software Comsol was used to establish a fuel reaction kinetics model.Through computational fluid dynamics (CFD) numerical simulation,the process of reaction in fluidized bed were well captured.The model was based on a two-fluid model and coupled mass transfer,heat transfer and chemical reac-tions.This study showed that the fluidized bed presents a flow structure in which gas and solid coexist.There was a high temperature zone in the middle and lower parts of the fluidized bed.It could be seen from the results of the flow field simulated that the fluidized bed was beneficial to the progress of the gasification reaction.     

Molecular Dynamics Simulations Based on 1-Phenyl-4-Benzoyl-1-Hydro-Triazole ERRα Inverse Agonists

Estrogen-related receptor α (ERRα), which is overexpressed in a variety of cancers has been considered as an effective target for anticancer therapy. ERRα inverse agonists have been proven to effectively inhibit the migration and invasion of cancer cells. As few crystalline complexes have been reported, molecular dynamics (MD) simulations were carried out in this study to deepen the understanding of the interaction mechanism between inverse agonists and ERRα. The binding free energy was analyzed by the MM-GBSA method. The results show that the total binding free energy was positively correlated with the biological activity of an inverse agonist. The interaction of the inverse agonist with the hydrophobic interlayer composed of Phe328 and Phe495 had an important impact on the biological activity of inverse agonists, which was confirmed by the decomposition of energy on residues. As Glu331 flipped and formed a hydrogen bond with Arg372 in the MD simulation process, the formation of hydrogen bond interaction with Glu331 was not a necessary condition for the compound to act as an inverse agonist. These rules provide guidance for the design of new inverse agonists.     

A Facile Approach toward Thermoplastic Triple-Shape Memory Polymers

In this work, a ternary blend of polyolefin elastomer (POE), lauric acid (LA), and poly(ε-caprolactone) (PCL) with triple-shape memory effect (triple-SME) is reported. LA and PCL exhibit distinct thermal transitions and construct two reversible switching networks capable of fixing and releasing different temporary shapes under a mild condition. The ternary blend shows excellent triple-shape memory properties and good toughness. Besides, the permanent shape can be reconfigured by a simple thermal treatment. These particular features make the novel blend a competitive candidate for diverse applications. And the creative combination of crystalline small molecule and semicrystalline polymer expands the freedom for producing triple-shape memory polymers (triple-SMPs).     

A Strategy of Liquid-Grafted Slippery Sponges with Simultaneously Enhanced Absorption and Desorption Performances for Crude Oil Spill Remediation

Crude oil spill accidents pose a worldwide environmental threat. Oleophilic and hydrophobic absorbents that can selectively absorb oil from water have shown promising application potential in oil spill remediation. Simultaneous optimization of the absorption and desorption speed of absorbents towards oil is highly desirable for their recyclable usage, but remains a great challenge, because these two properties are generally conflicting. Here, a facile and ingenious strategy is proposed to tackle the above challenge via surface modification of porous sponges with highly flexible linear polydimethylsiloxane (LPDMS) brushes. The LPDMS brushes feature liquid-like properties at room temperature owing to its extremely low glass transition temperature, and act as a covalently-grafted lubrication layer throughout the 3D network channels of the sponge, which can minimize contact angle hysteresis and reduce friction between oil and sponge channel. Compared to the prevalent cross-linked polydimethylsiloxane (CPDMS) modification strategy, sponges modified with LPDMS brushes not only shows significantly enhanced absorption speed, but also exhibits superior desorption dynamics towards viscous crude oils. The design strategy of slippery sponges with liquid-like molecules may open a new avenue for developing advanced absorbents with simultaneously enhanced absorption and desorption performances for liquid separation and purification applications.     

Effect of SiC nanowhisker addition on microstructure and mechanical properties of regenerated cemented carbides by low-pressure sintering

The hardness and toughness of regenerated cemented carbides, in general, are contradictory. Therefore, it is critical to explore regenerated cemented carbides with both high hardness and high toughness. In this study, regenerated WC-8-wt% Co cemented carbide with SiC nanowhisker were prepared by low-pressure sintering. The influence of SiCw contents on the microstructure and mechanical properties of regenerated WC-8-wt% Co cemented carbide was investigated. The results indicated that the hardness, density, flexural strength, and fracture toughness of regenerated cemented carbide first increased and then decreased with the addition of SiCw. The Vickers hardness, density, flexural strength, and fracture toughness could reach 1575 HV, 14.6 g/cm³, 2204 MPa, 16.85 MPa·m^1/2, respectively, with SiCw content 0.5 wt%, which were increased by 14.4%, 0.7%, 12.2%, and 17.3%, respectively, when compared with the regenerated cemented carbide without SiCw. The lowest friction coefficient and the best wear resistance could be also reached when 0.5-wt% SiCw was added. The fracture mechanism of the regenerated cemented carbide contained both transgranular and intergranular fracture through the microscopic observation of fracture surface via scanning electron microscope.     

结晶法提纯在高纯镓生产中的应用

目前镓提纯方法多采用电解法。单一电解法提纯镓．由于一些主要杂质析出严重，常常形成个别杂质元素超标，造成产品品级降低。本项目通过对电解尾料结晶法镓提纯新方法的研究，进一步补充完善提纯工艺路线，提高产品质量的稳定性。将该方法与湿法提纯技术相联合．可以提高产品产出率，降低生产成本。     

熔融织构YBCO块样品的磁特性研究

对MTG区熔生长法,慢冷法,粉末熔融生长法这3种方法制备的熔融织构YBCO块样品进行了交流磁化率和磁阻的测量。根据实验结果计算了样品的钉扎势,并且发现3种方法制备的样品在150 mT外磁场下均显示出基本消除弱连接的特性;粉末融熔生长法所制样品中有较纯净123相和较好织构,质量最好。     

Nanoscale Studies of the Early Stages of Oxidation of a TiAl-Base Alloy

The strategy to perform nanoscale studies of the initial stages of oxidation of TiAl involved first gaining some information on the electronic structure of pure TiO₂ surfaces and then on TiAl surfaces before and after oxidation both in low- and high-oxygen potentials. Both materials were studied in atomically-cleaned states generated by repeated sputtering and heating. It was found that the oxygen vacancies created additional defect states in the band gap of stoichiometric TiO₂. The results obtained on TiO₂ were used as fingerprints to study the oxide nucleation. The results on the initial stages of oxidation of TiAl confirm the nucleation of Ti₂O₃ islands of nanometer size and monolayer height in a low-oxygen-pressure environment, whilst a TiO₂ layer developed in an atmospheric environment. The ledges on atomically-cleaned surfaces usually acted as nucleation sites.