Fluoride-mediately solvothermal synthesis and tunable photocatalytic selectivity of urchin-like ZrO2 hollow microspheres

Photocatalysts often show excellent performances on the basis of their surface state of exposed faces with high reactivity, but unfortunately surfaces of this type are usually concealed into the interior of crystals for their high surface energy. We report here a possibility that for fluorine-terminated surfaces of monoclinic ZrO₂, these higher-energy surfaces could be retained and exposed. Urchin-like ZrO₂ hollow microspheres (UZHS) composed of nanoribbons with exposed (010) facets are obtained through a fluoride mediately solvothermal method. We prove the stabilization effect of fluorine adsorption on (010) facets by density functional theory calculations. More interestingly, UZHS exhibit tunable photocatalytic selectivity in dye degradation. The fluorinated UZHS exhibit good performances both on decomposing Congo red (CR) and methylene blue, while the surface-modified UZHS by calcination only favor decomposition of CR.     

弱相互作用调控表面活性剂自组装(Ⅱ)——表面活性剂的结构与设计

介绍了表面活性剂的结构、性质以及分类,综述了阴离子表面活性剂、阳离子表面活性剂、两性离子表面活性剂、非离子表面活性剂的分子间弱相互作用。另外,简述了低聚型表面活性剂和其他新型表面活性剂的结构及应用。     

胶东一体化背景下天然气发展策略研究

大力发展天然气对于促进能源结构优化调整和大气污染防治具有重要意义,是实现"碳达峰""碳中和"的重要路径.借力胶东一体化发展战略的提出,引领胶东五市天然气基础设施协同发展,促进胶东一体化战略在能源领域的实施.     

基于儿童使用主体的建成环境评价尺度研究

评价尺度是建筑使用后评价的基 本问题之一，它是使用者评判建成环境好 坏、优劣的重要测度标准。为弥补目前环境 评价尺度研究方面的缺失，建立与儿童使用 主体相一致的建成环境评价尺度，对儿童常 用语义量词进行汇总和筛选，采用五级线 分刻度方法进行问卷调查研究。基于儿童的 理解，通过问卷试验分析，结果表明：双侧 5级区间评价尺度为：很（负面）；有点（负 面）；中等；有点（正面）；很（正面）；单侧 5级区间评价尺度为：不；好像有点；比较； 很；特别。     

Stabilization of 6H-Hexagonal SrMnO3 Polymorph by Al2O3 insertion

We demonstrate the structural evolution of polymorphic phases in Al₂O₃-inserted SrMnO₃ ceramics synthesized by solid state reaction. While the 4H-hexagonal phase is predominant in pure SrMnO₃ ceramics, a small amount of 6H-hexagonal polymorph is identified in addition to the primary 4H-hexagonal SrMnO₃ and the secondary hexagonal SrAl₂O₄ phases in the as-sintered ceramics, evidenced by x-ray diffraction and subsequent Rietveld refinement analyses. The existence of the 6H-hexagonal SrMnO₃ phase is corroborated using Raman spectroscopy. The chemical compositions and electronic structures of the Al₂O₃-inserted SrMnO₃ compounds are also examined using energy dispersive spectroscopy and x-ray photoelectron spectroscopy, respectively. The first-principles calculations reveal that there is no clear difference between the total energies of 4H- and 6H-hexagonal polymorphs regardless of the presence/absence of Sr and oxygen vacancies. Possible origins are discussed with the estimation of actual strain based on the refined lattice parameter of 6H SrMnO₃.     

Spreading and Curing Behaviors of a Thermosetting Droplet-Silicone on a Heated Surface

Thermosetting materials are widely used as encapsulation in the electrical packaging to protect the core electronic components from external force, moisture, dust, and other factors. However, the spreading and curing behaviors of such kind of fluid on a heated surface have been rarely explored. In this study, we experimentally and numerically investigated the spreading and curing behaviors of the silicone(OE6550 A/B, which is widely used in the light-emitting diode packaging) droplet with diameter of ～2.2 mm on a heated surface with temperature ranging from 25 ℃ to 250 ℃. For the experiments, we established a setup with high-speed camera and heating unit to capture the fast spreading process of the silicone droplet on the heated surface. For the numerical simulation, we built a viscosity model of the silicone by using the Kiuna's model and combined the viscosity model with the Volume of Fluid(VOF) model by the User Defined Function(UDF) method. The results show that the surface temperature significantly affected the spreading behaviors of the silicone droplet since it determines the temperature and viscosity distribution inside the droplet. For surface temperature varied from 25 ℃ to 250 ℃, the final contact radius changed from ～2.95 mm to ～1.78 mm and the total spreading time changed from ～511 s to ～0.15 s. By further analyzing the viscosity evolution of the droplet, we found that the decreasing of the total spreading time was caused by the decrease of the viscosity under high surface temperature at initial spreading stage, while the reduction of the final contact radius was caused by the curing of the precursor film. This study supplies a strategy to tuning the spreading and curing behavior of silicone by imposing high surface temperature, which is of great importance to the electronic packaging.     

Design and synthesis of side-chain optimized poly(2,6-dimethyl-1,4-phenylene oxide)-g-poly(styrene sulfonic acid) as proton exchange membrane for fuel cell applications: Balancing the water-resistance and the sulfonation degree

Side-chain optimized poly (2,6-dimethyl-1,4-phenylene oxide)-g-poly (styrene sulfonic acid) (PPO-g-PSSA) is designed with balanced water-resistance and sulfonation degree. The PPO-g-PSSA is synthesized by controlled atom-transfer radical polymerization (ATRP) from brominated poly (2,6-dimethyl-1,4-phenylene oxide) (PPO-xBr) and ethyl styrene-4-sulfonate and followed by hydrolysis. A series of PPO-g-PSSA are prepared possessing different bromination degree (x) of PPO-xBr and polymerization degree (m) of the side-chains and the water-resistances of the fabricated membranes are investigated. The results show that a PPO-g-PSSA at relatively low x (x < 0.2) and high m (m > 4) exhibits good balance between the water-resistance and the sulfonation degree. Namely, it displays suitable proton conductivity with compromised water-resistance. Moreover, a maximum ion exchange capacity (IEC) of 3.24 mmol g^?1 is reached without the sacrifice of water-resistance. In addition, PPO-g-0.08PSSA-13 and PPO-g-0.14PSSA-4 are chosen characterized by thermogravimetric analysis, proton conductivities and mechanical properties. At 90% RH, the optimized PPO-g-0.08PPSA-13 possesses a proton conductivity of 37.9 mS cm^?1 at 40 °C and 45.5 mS cm^?1 at 95 °C, respectively.     

P-doped CoSe2 nanoparticles embedded in 3D honeycomb-like carbon network for long cycle-life Na-ion batteries

We report for the first time a Na-ion battery anode material composed of P-doped CoSe2 nanoparticles(P-CoSe2)with the size of 5-20 nm that are uniformly embed in a 3D porous honeycomb-like carbon network.High rate capability and cycling stability are achieved simultaneously.The honeycomb-like carbon network is rationally designed to support high electrical conductivity,rapid Na-ion diffusion as well as the accommodation of the volume expansion from the active P-CoSe2 nanoparticles.In particular,heteroatom P-doping within CoSe2 introduces stronger P-Co bonds and additional P-Se bonds that signif-icantly improve the structure stability of P-CoSe2 for highly stable sodiation/desodiation over long-term cycling.P-doping also improves the electrical conductivity of the CoSe2 nanoparticles,leading to highly elevated electrochemical kinetics to deliver high specific capacities at high current densities.Benefiting from the unique nanostructure and atomic-level P-doping,the P-CoSe2(2∶1)/C anode delivers an excel-lent cycle stability with a specific capacity of 206.9 mA h g-1 achieved at 2000 mA g-1 after 1000 cycles.In addition,this material can be synthesized using a facile pyrolysis and selenization/phosphorization approach.This study provides new opportunities of heteroatom doping as an effective method to improve the cycling stability of Na-ion anode materials.     

聚氨酯分散剂在液体靛蓝制备中的应用

采用异佛尔酮二异氰酸酯(IPDI)、聚乙二醇200、400、600、800(PEG200、PEG400、PEG600、PEG800)、2,2-二羟甲基丙酸(DMPA)、1-苯基-1,2-乙二醇、中和剂三乙胺(TEA)、甲乙酮肟等为原料,制备了一种阴离子聚氨酯分散剂.通过FTIR、GPC、TG表征了分散剂的结构与性能.利用自制的分散剂采用研磨法制备了液体靛蓝分散液,以液体靛蓝分散液粒径、离心稳定性、储存稳定性为指标,探讨了分散剂链长、用量对分散液性能的影响.结果表明,研磨1 h后,以PEG400为软段合成的聚氨酯分散剂用量为染料质量的60％时制备的液体靛蓝粒径为277.1 nm,1000 r/min离心稳定性达到93.98％,3000 r/min离心稳定性为51.13％,常温放置7 d后粒径变化在20 nm以内,染色后织物的颜色深度(K/S)为10左右,约是粉状靛蓝染色K/S的2倍,染色织物的颜色性能并未改变,SEM显示分散体颗粒大小分布均匀,与分散剂甲基萘磺酸钠的甲醛缩合物(MF)和木质素85A相比,其分散体系稳定性差别不大.