Graphene‐Supported Mesoporous Carbons Prepared with Thermally Removable Templates as Efficient Catalysts for Oxygen Electroreduction

Graphene‐supported mesoporous carbons with rich nitrogen self‐doped active sites (N‐MC/rGO) are prepared by direct pyrolysis of a graphene‐oxide‐supported polymer composite embedded with massive, evenly distributed amorphous FeOOH that serve as efficient thermally removable templates. The resulting N‐MC/rGO catalysts exhibit high surface areas and apparent electrocatalytic activity for oxygen reduction reaction in alkaline media. Among the series, the sample prepared at 800 °C displays the best performance with a more positive onset potential, higher limiting currents, much higher stability, and stronger poison resistance than commercial Pt/C. This is ascribed to the synergetic functions of the highly conductive graphene support and the mesoporous N‐doped carbons that effectively impede the restacking of the graphene sheets and enhance the exposure of the rich nitrogen self‐doped active sites.     

具有二次微粒结构的高分散型白炭黑的应用测试

采用两步新工艺法制备具有二次微粒结构的高分散型白炭黑,并对其性能进行研究.在反应过程中,第一步和第二步反应分别采用不同的反应条件,产生了两种不同形态的小簇团,形成具有新结构的聚集体.对其应用性能进行研究,将其添加到丁苯橡胶中,并对添加白炭黑的胶样硫化,对其撕裂和拉伸性能进行分析.结果表明优于传统白炭黑.     

Dynamic response and microstructure evolution of the finite steel target subjected to high velocity impact by copper explosively formed projectile

The dynamic deformation of the finite steel target subjected to high velocity impact of copper explosively formed projectile is investigated by optical, scanning, and transmission electron microscopy. Morphology analysis of fracture surfaces indicates that the copper remainder plated to the crater wall shows extremely plastic deformation, which consists of elongated parabolic dimples, and the mild carbon steel target exhibits excellent brittle features that material fails mainly along the cleavage facets on the rear surface of target under strong impact of explosively formed projectile. In the surface of crater, the whole part of copper remainder and partial material of steel target undergoes completely dynamic recrystallization. The layer thickness of dynamic recrystallization zone, which displays an extreme plastic flow in solid state, is about 21.3 μm in steel target, and the average size of the refined grains significantly decreases to approximately 200 nm. Theoretically calculated results indicate that the temperature increase is associated with shock wave and plastic deformation of steel target and can reach 1352 K, which is 0.75T_m (where T_m is the melting temperature of steel target). The change in microhardness from the crater wall to the matrix of target is consistent with micro‐deformation of grains, and maximum microhardness is observed on the interface between dynamic recrystallization and severe plastic deformation zones of steel target.     

“Quasi‐freestanding” Graphene‐on‐Single Walled Carbon Nanotube Electrode for Applications in Organic Light‐emitting Diode

An air‐stable transparent conductive film with “quasi‐freestanding” graphene supported on horizontal single walled carbon nanotubes (SWCNTs) arrays is fabricated. The sheet resistance of graphene films stacked via layer‐by‐layer transfer (LBL) on quartz, and modified by 1‐Pyrenebutyric acid N‐hydroxysuccinimide ester (PBASE), is reduced from 273 Ω/sq to about 76 Ω/sq. The electrical properties are stable to heat treatment (up to 200 ºC) and ambient exposure. Organic light‐emitting diodes (OLEDs) constructed of this carbon anode (T ≈ 89.13% at 550 nm) exhibit ≈88% power efficiency of OLEDs fabricated on an ITO anode (low turn on voltage ≈3.1 eV, high luminance up to ≈29 490 cd/m², current efficiency ≈14.7 cd/A). Most importantly, the entire graphene‐on‐SWCNT hybrid electrodes can be transferred onto plastic (PET) forming a highly‐flexible OLED device, which continues to function without degradation in performance at bending angles >60°.     

在地实践语境下的上海红色文创产品情感化设计探析

目的 探析在地实践语境下,红色文化转化为文创产品的设计路径,以此寻求上海红色文创产品设计的新思路,助力红色文化的传承与发扬。方法 通过对上海红色文创产品设计的现状分析确立地域特色的重要性。基于情感化设计理念,将上海红色文化资源分层整理,并深入研究在地性背景下消费主体各层级的情感需求及文化转译的方法。最终构建出基于情感化设计理念的红色文创产品在地性实践模型,并通过设计团队的实践案例进行展示。结论 从情感满足的角度出发,提出在本能层级上以红色文化符号的地域识别性为提取原则并确保文化转译过程中的准确性;行为层级上在以海派崇实性为基准设定产品功能的同时强调产品的文化体验;反思层级上侧重通过产品理念、寓意、品质等要素的设计构建红色精神与上海价值的双重认同并将其长效延续的思路,力求为上海红色文创产品的地方性特色呈现提供积极的现实意义和参考价值。     

Improvement in transdermal drug delivery performance by graphite oxide/temperature-responsive hydrogel composites with micro heater

Transdermal drug delivery system (TDDS) was prepared with temperature-responsive hydrogel. The graphite was oxidized and incorporated into hydrogel matrix to improve the thermal response of hydrogel. The micro heater was fabricated to control the temperature precisely by adopting a joule heating method. The drug in hydrogel was delivered through a hairless mouse skin by controlling temperature. The efficiency of drug delivery was improved obviously by incorporation of graphite oxide due to the excellent thermal conductivity and the increased interfacial affinity between graphite oxide and hydrogel matrix. The fabricated micro heater was effective in controlling the temperature over lower critical solution temperature of hydrogel precisely with a small voltage less than 1 V. The cell viability test on graphite oxide composite hydrogel showed enough safety for using as a transdermal drug delivery patch. The performance of TDDS could be improved noticeably based on temperature-responsive hydrogel, thermally conductive graphite oxide, and efficient micro heater.     

Removal of ammonium from wastewater using calcium form clinoptilolite

The paper concerns the removal of ammonium ions from aqueous solution using a modified clinoptilolite-Ca(2+)-formed clinoptilolite (CaY) prepared from natural clinoptilolite. The batch study results show that the pH has an effect on ammonium adsorption capacity as it can influence both the character of the exchanging ions and the clinoptilolite itself; the CaY has a high selectivity to NH(4)(+) and the exchange decreases with increasing temperature; ammonium ion uptake onto CaY was suitably described by the Langmuir model. The column results indicated that the effluent of simulated wastewater treated with CaY could meet the integrated wastewater discharge standard of China, and CaY can be circulated through regenerating by Ca(OH)(2).