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11.
Bifunctional Polyacrylonitrile Fiber‐Mediated Conversion of Sucrose to 5‐Hydroxymethylfurfural in Mixed‐Aqueous Systems 下载免费PDF全文
Dr. Xian‐Lei Shi Min Zhang Huikun Lin Minli Tao Prof. Dr. Yongdan Li Prof. Dr. Wenqin Zhang 《化学:亚洲杂志》2015,10(3):752-758
A highly efficient catalytic system composed of a bifunctional polyacrylonitrile fiber (PANF‐PA[BnBr]) and a metal chloride was employed to produce 5‐hydroxymethylfurfural (HMF) from sucrose in mixed‐aqueous systems. The promoter of PANF‐PA[BnBr] incorporates protonic acid groups that promote the hydrolysis of the glycosidic bond to convert sucrose into glucose and fructose, and then catalyzes fructose dehydration to HMF, while the ammonium moiety may promote synergetically with the metal chloride the isomerization of glucose to fructose and transfer HMF from the aqueous to the organic phase. The detailed characterization by elemental analysis, FTIR spectroscopy, and SEM confirmed the rangeability of the fiber promoter during the modification and utilization processes. Excellent results in terms of high yield (72.8 %) of HMF, superior recyclability (6 cycles) of the process, and effective scale‐up and simple separation procedures of the catalytic system were obtained. Moreover, the prominent features (high strength, good flexibility, etc.) of the fibers are very attractive for fix‐bed reactor. 相似文献
12.
《化学:亚洲杂志》2017,12(10):1052-1056
The β‐cyclodextrin‐assisted aqueous‐exfoliation method was used to prepare transition‐metal dichalcogenide (TMD) nanosheets, in a cheap, highly efficient, scalable and environmentally friendly manner. As study cases, MoS2 and ReS2 nanoflakes were prepared according to this method. Particularly, the effective exfoliation of ReS2 crystals in an aqueous environment was observed for the first time. Moreover, exfoliated nanomaterials can be readily utilized in hydrogen evolution reactions (HERs) as noble‐metal‐free catalysts. This work provides new opportunities for highly efficient exfoliation of TMDs and other 2D nanomaterials into few‐layer nanosheets in aqueous media. Their production process showed high biocompatibility, broad applicability and excellent sustainability. 相似文献
13.
《Comptes Rendus Chimie》2017,20(7):704-709
Aluminophosphate and silicoaluminophosphate molecular sieves with both five (AFI) and eleven (AEL) type structures are synthesized by hydrothermal crystallization at 473 K, using tripropylamine and dipropylamine as a structure-directing template. The as-prepared AFI and AEL sieves are characterized and then assessed as sorbents for uranium (VI) from radioactive effluents. The sorption process is used to reduce the volumes of effluents and convert them into a stable solid waste. The batch experimental studies are carried out to evaluate the AEL and AFI structure effect on the removal of uranium. The AlPO4-5, SAPO-5, AlPO4-11 and SAPO-11 are applied to radioactive effluents with different activities obtained from Nuclear Research Center of Draria, Algeria. Important decontamination factor values are obtained for AFI sorbents. Thermodynamic parameters, namely, the enthalpy (ΔH), entropy (ΔS) and free energy (ΔG) for each sorption process are calculated. The collected results indicated that sorbents are effective materials for the removal of uranium (VI) ions, the sorbent with AFI structure being a highly effective material for the removal of uranium (VI) ions from nuclear effluents. 相似文献
14.
通过建立模型分析了近6年来的北京市高考试题。从试题水平来看,学生需要建立水溶液问题的基本认识角度和分析思路;从能力要求来看,部分试题实现了对关键能力的融合考查。在此基础上进行试题命制和施测,发现学生不能自主调用多个认识角度形成思路,提出了比较不同问题情境中的共同认识角度与建立“水溶液-平衡”二元分析模型的教学改进策略。 相似文献
15.
Enrica Bortolamiol Giacomo Isetta Isabella Caligiuri Dr. Nicola Demitri Prof. Dr. Stefano Paganelli Prof. Dr. Flavio Rizzolio Dr. Thomas Scattolin Prof. Dr. Fabiano Visentin 《欧洲无机化学杂志》2023,26(22):e202300084
A general synthetic entryway into novel cationic Pd(II) indenyl complexes bearing one alkyl/aryl phosphine and one N-heterocyclic carbene is reported. All metal complexes have been exhaustively characterized by spectroscopic and structural analyses, highlighting that the indenyl fragment has an hapticity intermediate between η3 and η5. Most of the target complexes are stable in solid state and in solution for a long time. Two different applications of these organopalladium compounds are proposed. Firstly, they have been tested as antiproliferative agents towards three different ovarian cancer cell lines, showing a cytotoxicity significantly higher than that of cisplatin, with a clear dependence on the nature of the coordinated phosphine. Moreover, the similar cytotoxicity towards cisplatin-sensitive and cisplatin-resistant cell lines suggests that these new palladium derivatives act with a different mechanism of action with respect to classical platinum-based drugs. Finally, the water-soluble palladium complexes bearing 1,3,5-triaza-7-phosphaadamantane (PTA) have demonstrated interesting catalytic performances in Suzuki–Miyaura coupling in aqueous media, being, inter alia, readily and efficiently recyclable. 相似文献
16.
锌具有原料丰富、质量轻便、金属导电性与延展性好以及理论比容量高等优势,可以作为绿色可充电电池的理想电极材料。其中,以中性或弱酸性水溶液为电解质、锌为负极的锌基水系电池具有安全性高、电池材料廉价无毒、制备工艺简单、环境友好等特点,在储能和动力电池领域具有极高的应用价值和发展前景。但电池充放电过程中伴随的锌枝晶、析氢、腐蚀、钝化等问题限制了其实际应用。本文综述了锌基水系电池负极存在的问题及当前的解决策略,并对其负极研究发展方向进行了展望。 相似文献
17.
The determination of two imidazoline derivatives [oxymetazoline HCl (OXY) and xylometazoline HCl (XYLO)] was described using different potentiometric platforms. The first electrode type was constructed using tetraphenyl borate (TPB) as anionic exchanger with β-cyclodextrins (β-CD) as ionophore forming oxymetazoline-tetraphenyl borate (OXY-TPB) and xylometazoline-tetraphenyl borate (XYLO-TPB), respectively. The second electrode type was prepared by modification of the first type by conjugation with magnetic iron oxide nanoparticles (MNP) forming (OXY-MNP) and (XYLO-MNP). The synthesized electrodes were fully characterized. The effect of magnetic nano-sized particles as a highly dispersible material with β-CDs on the electrode characteristics was investigated and compared against the classical electrodes. The response time, working pH range and selectivity coefficients were studied. The functionalized nano-electrodes (OXY-MNP and (XYLO-MNP) were found to be more sensitive than the classical electrodes with linearity ranges (1×10−6–1×10−2 M). The functionalized nano-electrodes were successfully applied for the in-line analysis of OXY and XYLO in pharmaceutical dosage forms and spiked rabbit aqueous humor samples with no prior extraction of treatment. This suggests the future use of these electrodes in clinical studies of both drugs of interest. 相似文献
18.
固态电池以其高安全性和高能量密度而备受关注。石榴石型固体电解质(LLZO)由于具有较高的离子导电性和对锂金属的稳定性,在固态电池中具有应用前景,但陶瓷与锂金属较差的界面接触会导致高的界面阻抗和可能形成的枝晶穿透。我们利用LLZO表层独特的H+/Li+交换反应,提出了一种简便有效的金属盐类水溶液诱发策略,在电解质表面原位构建ZnO亲锂层,界面处LiZn合金化实现紧密连续的接触。引入改性层后,界面阻抗可显著降低至约10Ω·cm2,对称电池能够在0.1mA·cm-2的电流密度下实现长达1000h的长循环稳定性。匹配正极LiFePO4(LFP)或LiNi0.5Co0.2Mn0.3O2(NCM523)的准固态电池在室温下能够稳定循环100次以上。 相似文献
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