Effects of Precursors and Carbon Nanotubes on Electrochemical Properties of Electrospun Nickel Oxide Nanofibers-Based Supercapacitors

Supercapacitors have been considered as one of the main energy storage devices. Recently, electrospun nanofibers have served as promising supercapacitor electrodes because of their high surface area, high porosity, flexibility, and resistance to aggregation. Here, we investigate the effects of electrospinning parameters and nickel precursors on the nanostructure of electrospun nickel oxide (NiO), as well as on their electrochemical performance as supercapacitor electrodes. In contrast to the case of using nickel nitrate, increasing the nickel acetate molar concentration maintains the flexible fibrous sheet morphology of the as-spun sample during the polycondensation and calcination of NiO. As a result, our flexible electrode of NiO nanofibers derived from nickel acetate (NiO-A) exhibits much better electrochemical performance values than that of nickel nitrate-derived NiO. To further improve the electrochemical storage performance, we combined NiO-A nanofibers with single-walled carbon nanotubes (CNTs) as a hybrid electrode. In both half-cell and full-cell configurations, the hybrid electrode displayed a higher and steadier areal capacitance than the NiO-A nanofibers because of the synergetic effect between the NiO-A nanofibers and CNTs. Altogether, this work demonstrates the potency of the hybrid electrodes combined with the electrospun NiO-A nanofibers and CNTs for supercapacitor applications.     

Shehu Transform: Extension to Distributions and Measures

This paper improves the computational aspect of the Shehu transform. An inversion formula is given. Finally the Shehu transform is extended to distributions and measures.     

乙醇在Ni-ZnO-ZrO_2-YSZ阳极SOFC上的发电性能

为考察乙醇用于固体氧化物燃料电池的可行性,用柠檬酸溶胶-凝胶制备阳极催化材料Ni-ZnO-ZrO2,利用机械混合法制备Ni-ZnO-ZrO2-YSZ(Y2O3稳定的ZrO2)阳极。用涂覆法,在YSZ电解质上,制备了Ni-ZnO-ZrO2-YSZ/YSZ/LSM(La0.85Sr0.15MnO3)与Ni-YSZ/YSZ/LSM的单体电池。在不同蒸发器操作温度、电池操作温度和乙醇蒸气流量下,以乙醇为燃料进行发电实验,对两种阳极的电池发电性能进行比较。实验结束后,用SEM检测了两种电池阳极的表面。结果表明,Ni-ZnO-ZrO2-YSZ阳极SOFC的电池输出性能明显高于Ni-YSZ阳极,且Ni-ZnO-ZrO2-YSZ阳极具有较好的抗积炭能力。     

Performance of cathode-supported SOFC with Ni0.5Cu0.5–CGO anode operated in humidified hydrogen and in low-concentration dry methane

A Ni_0.5Cu_0.5–CGO (Ce_0.8Gd_0.2O_1.9) anode in a LSM ((La_0.75Sr_0.25)_0.95MnO_3?δ )–CGO cathode-supported SOFC is tested in humidified H₂ (3% H₂O) and in low concentration of dry methane, respectively. After co-sintering at 1,300?°C, it was found that the A-site-deficient LSM effectively hindered the formation of La₂Zr₂O₇ or SrZrO₃. The OCVs of the cell are as high as 1.132, 1.14, and 1.147?V in humidified H₂ and 1.314, 1.269, and 1.2?V in 14.8% of dry methane at 850, 800 and 750?°C, respectively, indicating that the ScSZ electrolyte film prepared by the present method is dense enough. The corresponding peak power densities are 0.396, 0.287, and 0.19?W?cm^?2 in humidified H₂ and 0.249, 0.164, and 0.096?W?cm^?2 in 14.8% of dry methane at 850, 800, and 750?°C, respectively. The prepared cathode-supported SOFC with NiCu–CGO bimetallic anode shows long-term stability when dry methane is used as fuel.     

Study of the fluid flow characteristics in a porous medium for CO2 geological storage using MRI

The objective of this study was to understand fluid flow in porous media. Understanding of fluid flow process in porous media is important for the geological storage of CO₂. The high-resolution magnetic resonance imaging (MRI) technique was used to measure fluid flow in a porous medium (glass beads BZ-02). First, the permeability was obtained from velocity images. Next, CO₂–water immiscible displacement experiments using different flow rates were investigated. Three stages were obtained from the MR intensity plot. With increasing CO₂ flow rate, a relatively uniform CO₂ distribution and a uniform CO₂ front were observed. Subsequently, the final water saturation decreased. Using core analysis methods, the CO₂ velocities were obtained during the CO₂–water immiscible displacement process, which were applied to evaluate the capillary dispersion rate, viscous dominated fractional flow, and gravity flow function. The capillary dispersion rate dominated the effects of capillary, which was largest at water saturations of 0.5 and 0.6. The viscous-dominant fractional flow function varied with the saturation of water. The gravity fractional flow reached peak values at the saturation of 0.6. The gravity forces played a positive role in the downward displacements because they thus tended to stabilize the displacement process, thereby producing increased breakthrough times and correspondingly high recoveries. Finally, the relative permeability was also reconstructed. The study provides useful data regarding the transport processes in the geological storage of CO₂.     

新疆石榴中磷含量的测定及其对人体健康的影响

采用钼蓝光度法借助722型分光光度计在波长660nm处测定了新疆石榴中磷的含量.实验结果表明:新疆石榴籽粒和果皮的总含磷量及石榴籽粒的含磷量分别为12.798mg/100g和11.033mg/100g,完全符合石榴中的标准磷含量为8.9-13mg/100g范围.而石榴汁含磷量为8.68×10-2mg/100mL,含磷量比较低.研究确定了新疆石榴中磷的含量,证明了新疆石榴独特的食用和药用价值和对人体健康的积极影响.     

固定化Sn/氯化胆硷络合物制备Sn-β分子筛催化剂用于葡萄糖-果糖异构化反应

在水溶液中锡盐与β分子筛金属化过程中很容易水解为氢氧化物,因此,制备高度分散的、以孤立形式存在的锡物种非常具有挑战性.我们先采用SnCl2/氯化胆硷(ChCl)络合物将锡物种固定在高硅的商品化的β分子筛上,然后焙烧就可很方便地在水溶液条件下制得了高度分散于β分子筛上的锡物种.电镜照片、紫外-可见光光谱和X射线衍射结果证实了这一点.ChCl的存在促进了锡物种与分子筛的结合.担载(1-2)wt%Sn的β分子筛在葡萄糖-果糖异构化反应中表现出较高的催化活性和选择性.     

柳兰花蜜腺的发育解剖学研究

柳兰花蜜腺杯状,贴生于凹形的花托内壁上,属花托蜜腺,它由分泌表皮,产蜜组织及亚腺组织构成,分泌表皮由一层细胞组成,具变态气孔,角质层薄。产蜜组织由１５￣２０层细胞组成,无维管束,但在其外侧的亚腺组织中有维管束,柳兰花蜜腺发育早期无特定的原始细胞,是由花托内周表面细胞特化而成的,在蜜腺发育过程中,蜜腺细胞内的液泡,淀粉粒有明显的动态变化,其变化与蜜汁的形成,分泌密切相关。