Accelerate the alkaline hydrogen evolution reaction of the heterostructural Ni2P@Ni(OH)2/NF by dispersing a trifle of Ru on the surface

Electrocatalytic water splitting for hydrogen production plays a vital role in the development of new energy field, but there is still a lack of low-content precious metal or cost-effective non-noble metal catalysts for the hydrogen evolution reaction (HER). Therefore, how to develop the catalysts with a smaller amount of precious metal to achieve higher performance is still a major challenge. Herein, we have fabricated Ru–Ni₂P@Ni(OH)₂/NF-2 heterostructure by phosphating Ni(OH)₂/NF and then anchoring Ru on the surface through wet chemical strategy. Benefiting from its optimal ΔG_H1 and synergistic effect, this Ru–Ni₂P@Ni(OH)₂/NF-2 catalyst shows superior electrocatalytic HER kinetics in alkaline electrolyte. A small overpotential of 31 mV is needed for this electrocatalyst to obtain the current densities of 10 mA cm^?2 with remarkable durability over 24 h. This work provides a new strategy for the preparation of effective HER electrocatalyst with a low precious metal content.     

A novel application of electrospinning technique in sublingual membrane: characterization,permeation and in vivo study

Isosorbide dinitrate–polyvinylpyrrolidone (ISDN–PVP) electrospinning fibers were formulated and explored as potentially sublingual membrane. The addition of polyethylene glycol (PEG) to the formulation improved flexibility and reduced fluffiness of the fiber mat. The scanning electron microscopy (SEM) demonstrated that the fibers tended to be cross-linking, and the crosslinking degree increased with the increase of PEG amount. The differential scanning calorimetry (DSC) indicated that ISDN existed in non-crystalline state in the fibers (except at the highest drug content). The infrared spectroscopy suggested that ISDN had better compatibility with the ingredients owing to the hydrogen bonding (or hydrophobic interactions). The fibers were highly favorable for the fabrication of sublingual membrane due to neutral pH, large folding endurance and rapid drug release (complete dissolution within 120 s). The permeation study of ISDN through both dialysis membrane (DM) and porcine sublingual mucosa (SM) were carried out. A significant relationship of drug permeation rate through DM and SM was built up, which indicated that DM could be used to partly simulate SM and assess formulation. The pharmacokinetic study in rats demonstrated that the electrospinning fiber membrane had a higher C_max and lower T_max compared to the reference preparation, and the relative bioavailability of the fiber membrane was 151.6%.     

CO2 sequestration in depleted methane hydrate deposits with excess water

The recent increase in atmospheric CO₂ concentration makes it necessary to investigate new ways to reduce CO₂ emissions. Simultaneously, natural gas hydrate mining technology is developing rapidly. The use of depleted methane hydrate (MH) deposits as potential sites for CO₂ storage is relatively safe and economical. This method can alleviate the shortage of hydrate displacement gas with CO₂. The purpose of this study was to investigate CO₂ hydrate formation characteristics during the seepage process—in reservoirs with excess water—and their effect on CO₂ storage. The experimental process can be divided into 5 parts: MH formation, water injection, MH dissociation, CO₂ hydrate formation, and CO₂ hydrate dissociation. Magnetic resonance imaging was employed to monitor the distribution of liquid water, and the effects of different parameters on the formation and dissociation of CO₂ hydrates were analyzed. It was found that a state of initial water saturation can effectively control hydrate saturation in artificial MH reservoirs for hydrate reservoirs with excess gas. In the process of CO₂ flow, initial water saturation was not the main controlling factor for CO₂ hydrate formation. Increasing the flow pressure and reducing the flow rate were beneficial for CO₂ hydrate formation. This study is of great significance for advancing the science of CO₂ geological storage in the form of deep‐sea hydrates.     

天然气与煤粉混烧技术在工业锅炉上的应用

介绍了在链条炉的基础上,以煤粉、天然气的悬浮燃烧方式配合火床燃烧的节能改造技术,对一台20t/h快装链条炉改造后,锅炉启动时升温速度提高,负荷调节的响应时间缩短,锅炉灰渣含碳量由原来的20％降低到5％以下,机械不完全燃烧损失大为降低.过量空气系数由改造前的2.5 ～3降低至1.2 ～1.3,大幅减少了锅炉排烟量,降低了锅炉排烟热损失.锅炉热效率由改造前的62％提高至改造后的77％ ～ 80％.     

Mechanical and thermal properties of biphenyldiol formaldehyde resin/gallic acid epoxy composites enhanced by graphene oxide

In this study, the gallic acid‐based epoxy resin (GA‐ER) and alkali‐catalysed biphenyl‐4,4′‐diol formaldehyde resin (BPFR) are synthesized. Glass fibre‐reinforced GA‐ER/BPFR composites are prepared. Graphene oxide (GO) is used to improve the mechanical and thermal properties of GA‐ER/BPFR composites. Dynamic mechanical properties and thermal, mechanical, and electrical properties of the composites with different GO content are characterized. The results demonstrate that GO can enhance the mechanical and thermal properties of the composites. The glass transition temperature, T_g, of the BPFR/GA‐ER/GO composites is 20.7°C higher than the pure resin system, and the 5% weight loss temperature, T_d5, is enhanced approximately 56.6°C. When the BPFR: GA‐ER mass ratio is at 4 : 6 and GO content is 1.0–1.2 wt %, the tensile and impact strengths of composites are 60.97 MPa and 32.08 kJ/m² higher than the pure resin composites, respectively. BPFR/GA‐ER composites have better mechanical properties, and can replace common BPA epoxy resins in the fabrication of composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42637.     

Design of a timed and controlled release osmotic pump system of atenolol

The objective of the article was to design a novel timed and controlled release osmotic pump (TCOP) containing atenolol as an active pharmaceutical ingredient and compare with a bilayer-core osmotic pump (BCOP) of atenolol. Different from BCOP, a modulating barrier was added to delay the drug release and obtain desired lag time (T_lag). The influences of the amount of pore-forming agent and modulating barrier, coating weight gain on the lag time (T_lag) and drug release rate (R_t) of TCOP were investigated. The central composite design-response surface methodology (RSM) was applied to optimize the formulation. Rhodamine B was added to modulating barrier to determine the release process of modulating barrier. A method used to correct the release profiles with a certain lag time by ΔT_lag and interpolating was applied to compare TCOP with BCOP. T_lag was directly proportional to the amount of modulating barrier and coating weight gain, but inversely related to the amount of pore forming agent, which were contrary to the effects on R_t. The optimal formulation including 60?mg PEO WSR N80, 3?g PEG 4000 and 6% coating weight gain could obtain a 3.59-h T_lag. According to the release of Rhodamine B, the modulating barrier was completely pushed out at ～5.0?h, longer than 3.59?h, therefore, atenolol along with remaining modulating barrier was released together between 3.59 and 5.0?h. By comparing with BCOP, the release profiles subtracting the part of lag time had no significant difference, yet R_t of TCOP presented a slight decrease.     

时速160～200km中速磁浮受流系统动力学研究

为了研究中速磁浮受流器在160～200 km/h速度等级下的运行状态,使用SIMPACK软件建立自由度为134的新型中速磁浮车辆动力学模型,计算得到160 km/h、180 km/h、200 km/h三种速度工况下的车辆右前侧受流器安装位置振动响应.将振动响应作为外部激励导入受流器-供电轨(靴轨)动力学模型,分别计算出三种速度下,静态接触力预设为120 N、130 N、130 N、140 N、140 N、150 N时受流器滑靴与供电轨间的动态接触力.结果表明,要使受流器在该速度工况下均能稳定工作,静态接触力预设值应分别不低于130 N、140 N、150 N.     

基于Halbach阵列的永磁被动阻尼方案研究

采用Halbach永磁体阵列的电动悬浮(PEDS)系统凭借其结构简单、稳定可靠及成本低等优势,在磁浮支撑领域具有很高的应用价值.本文以永磁电动系统为研究对象,针对其临界稳定特性,提出了一种侧面布置Halbach永磁阵列结构,利用磁阻力实现永磁电动悬浮系统垂向阻尼被动控制的阻尼方法.介绍了PEDS的悬浮原理,应用Ansoft软件进行了永磁电动系统的电磁仿真;搭建了带有阻尼模块的悬浮架模型;建立了悬浮系统的动力学模型,仿真阻尼方法的作用效果.仿真结果证明了该永磁被动阻尼方法作为电动悬浮系统阻尼方案的可行性,并对阻尼模块结构对振动抑制效果的影响进行了初步探究,为实际工程应用提供参考依据.