Helium conservation: Supply and demand projections in the USA reconsidered

In a recent paper, B.C. Liu developed and estimated a model of the helium market in the USA. There are significant shortcomings in both the data and the model specification. Some of the problem areas are examined here.     

Robust proton exchange membrane for vanadium redox flow batteries reinforced by silica-encapsulated nanocellulose

High ion selectivity and mechanical strength are critical properties for proton exchange membranes in vanadium redox flow batteries. In this work, a novel sulfonated poly(ether sulfone) hybrid membrane reinforced by core-shell structured nanocellulose (CNC-SPES) is prepared to obtain a robust and high-performance proton exchange membrane for vanadium redox flow batteries. Membrane morphology, proton conductivity, vanadium permeability and tensile strength are investigated. Single cell tests at a range of 40–140 mA cm⁻² are carried out. The performance of the sulfonated poly(ether sulfone) membrane reinforced by pristine nanocellulose (NC-SPES) and Nafion® 212 membranes are also studied for comparison. The results show that, with the incorporation of silica-encapsulated nanocellulose, the membrane exhibits outstanding mechanical strength of 54.5 MPa and high energy efficiency above 82% at 100 mA cm⁻², which is stable during 200 charge-discharge cycles.     

TCEP在羊毛角蛋白上的应用

介绍了羊毛角蛋白的溶解历史和三羧乙基膦(TCEP)在羊毛角蛋白上的应用。考虑到各种还原剂的优缺点,阐述了TCEP的优点和还原机理。三羧乙基膦是一种极为合适的部分还原试剂,对还原二硫键选择性极强。TCEP可以在很宽的pH值下将二硫键还原成巯基。TCEP广泛应用在多肽、蛋白质和细胞系统的二硫键还原及其螯合剂、配位剂。由于羊毛中含有大量的角蛋白,国内外学者将TCEP用于羊毛角蛋白的组分分析、改性和溶解。     

冰爽型面料性能测试方法的研究

研究了冰爽型面料的凉爽舒适性能,从面料的热湿性能、风格性能和透气性能等人手,采用模糊数学综合评判法、主成分分析法和手感触摸法对面料的凉爽舒适性能进行评价．并统计分析各物理指标与凉爽舒适性能的相关关系,得到透气率、湿阻、透湿率和热阻等指标可以作为冰爽型面料凉爽舒适性能的物理指标;同时研究表明能较准确反映冰爽型面料凉爽舒适性能的测试方法是主客观评判法相结合。     

GO@MIL-101的制备及其对水中Cr（Ⅵ）的去除

通过水热法制备了掺杂氧化石墨烯（GO）的金属有机框架GO@MIL-101,并考察了GO掺杂量对GO@MIL-101形貌和性质的影响规律。GO的掺杂影响了MIL-101晶体的形成过程。随着GO掺杂量的增加,GO@MIL-101晶体的完整性降低、粒径减小,团聚现象越发显著。GO@MIL-101能够有效去除溶液中的Cr（Ⅵ）,该过程符合拟二级动力学方程。由Langmuir吸附等温线拟合得到的最大吸附量与GO掺杂量有关,在2%[相对于Cr（NO₃）₃·9H₂O质量]时达到最大,这与此时GO@MIL-101同时具有较大的比表面积和较大的孔体积有关。Cr（Ⅵ）的去除过程伴随着溶液中NO₃^-浓度的升高以及pH的下降,电荷平衡计量分析表明MIL-101和GO@MIL-101对Cr（Ⅵ）的去除机制相同,主要依靠MIL-101的离子交换作用,并且所去除的Cr（Ⅵ）以CrO₄^2-形式存在于固相中。     

Photoassisted degradation of CI Reactive Red 195 using an Fe(III)‐grafted polytetrafluoroethylene fibre complex as a novel heterogeneous Fenton catalyst over a wide pH range

Polytetrafluoroethylene fibre was grafted with acrylic acid to form an effective ligand, which coordinated with Fe(III) ions to prepare an Fe(III)‐grafted polytetrafluoroethylene fibre complex. The photoassisted degradation of a typical azo dye, CI Reactive Red 195, using the Fe(III)‐grafted polytetrafluoroethylene fibre complex as a novel heterogeneous Fenton catalyst in a wide pH range of 3–9 was investigated. In order to achieve better degradation in a higher pH range, the effect of Fe content, incorporation of Cu(II) ions and UV light irradiation on dye degradation was also examined. The results indicated that dye degradation was effective in the presence of the Fe(III)‐grafted polytetrafluoroethylene fibre complex. Fast degradation of the dye can take place in an acidic environment. Increasing the Fe content or incorporating Cu(II) ions can significantly accelerate dye degradation, and UV light irradiation is much more effective than visible light irradiation in a higher pH range, especially in the alkaline pH range.     

工艺因子对于MFC中能量分配的协同效应分析

微生物燃料电池（MFC）以产电和代谢的方式利用系统能量实现有机物降解。针对运行过程中能量的不同分配需求,以pH、有机负荷、溶解氧、电导率和外电阻为工艺因子,采用正交实验方法优选最佳工艺条件,从而实现MFC能量流调控的目的。研究表明：在实验工况下,最高产电能量转化效率和生物代谢能量利用效率分别为8.74%和66.03%,负荷和外电阻对产电能量转化效率有显著影响,负荷和pH对能量利用效率有显著影响,系统能量主要以生物代谢方式被利用。由此可见,在同等负荷条件下,若将MFC作为电转化单元时应主要控制其外电阻,若需提高MFC的有机物降解能力时pH则是首要控制因素。     

利用大型综合实验教学提高大学生实践综合应用能力

对传统材料类实验存在的主要问题进行了分析,并结合我校复合材料与工程专业的特点提出了聚合物复合材料本科大型综合实验的新实验方案,培养学生对基础实验技能的综合应用能力,培养学生对知识的灵活运用能力。     

双(4-氟苯基)苯基氧膦磺酸钠盐的合成及表征

以双(4-氟苯基)苯基氧膦为起始原料,20%发烟硫酸为磺化试剂,分别合成了双(3-磺酸钠-4-氟苯基)-3’-磺酸钠苯基氧膦、4-氟苯基-(3’-磺酸钠-4’-氟苯基)-3″-磺酸钠苯基氧膦和双(4-氟苯基)-3’-磺酸钠苯基氧膦等3种单体,实验方法操作简便、反应后处理简单且收率较高,适用于产品的大规模制备。     

Coordination assemblies of CdII/ZnII/CoII with the 3-(pyridin-4-yl) benzoate tecton: Structural diversity and properties

Three novel coordination polymers{[CdL₂(HL)(H₂O)]·(H₂O)}_n (1), [Zn₂(OH)L₃]_n (2) and [CoL₂(H₂O)]_n (3) have been hydrothermally synthesized from M(NO₃)₂·nH₂O (M^II = Cd^II, Zn^II and Co^II) and an unsymmetrical tecton 3-(pyridin-4-yl) benzoic acid (HL). All complexes show interesting structural patterns, namely, unprecedented 1D double-stranded supramolecular clasp for 1, novel (3,5,6)-connected helical tubular double layer for 2, 2-fold interpenetrating cds network for 3. The fluorescent and thermal properties of complexes 1, 2 and/or 3 have also been investigated.