Effect of environmental conditions on the sorption of radiocobalt from aqueous solution to treated eggshell as biosorbent

Carbonate hydroxylapatite (CHAP), prepared from eggshell waste, was used to remove ⁶⁰Co(II) from aqueous solutions. The sorption of ⁶⁰Co(II) on CHAP as a function of contact time, pH, ionic strength and foreign ions in the absence and presence of humic acid and fulvic acid under ambient conditions was studied. The sorption of ⁶⁰Co(II) on CHAP was strongly dependent on pH and ionic strength. The thermodynamic parameters (ΔH ⁰, ΔS ⁰, ΔG ⁰) of ⁶⁰Co(II) sorption on CHAP were calculated from the temperature-dependent sorption isotherms, and the results indicated that the sorption process of ⁶⁰Co(II) on CHAP was endothermic and spontaneous. At low pH, the sorption of ⁶⁰Co(II) was dominated by outer-sphere surface complexation and ion exchange with Na⁺/H⁺ on CHAP surfaces, whereas inner-sphere surface complexation was the main sorption mechanism at high pH. Experimental results also indicated that CHAP was a suitable low-cost adsorbent for pre-concentration and solidification of ⁶⁰Co(II) from large volumes of aqueous solutions.     

四氢异喹啉衍生物的合成研究

以间甲氧基苯乙胺和氯甲酸乙酯为原料,通过亲核取代、关环、铝锂氢还原、脱甲基以及在N位上Boc保护及脱保护等9步反应得到一系列重要的1,2,3,4-四氢异喹啉及其衍生物.产物的结构经核磁共振氢谱、红外光谱及元素分析确证.与传统四氢异喹啉衍生物的合成工艺相比,该工艺反应条件温和、简便、经济、产率高且对环境友好.     

费托反应本征动力学中合成气分压对反应速率的影响

利用高通量动力学反应器测量了本征条件下钴基费托催化剂上反应物消耗速率rCO和产物生成速率rCH4随固定床床层的分布,并考察了它们在不同入口分压(p0CO,p0H2)条件下的变化.结果表明,入口氢碳比(H/C)0=p0H2/p0CO为影响速率的敏感外部变量,反应速率随(H/C)0的增加而加快;而合成气总压p0H2+CO则...     

粒径可控的纳米铁酸铋的制备及其光催化性能

采用改进的聚丙烯酰胺凝胶法制备了BiFeO3纳米颗粒,利用热重-差热、红外光谱及X射线衍射等手段研究了干凝胶的热分解及BiFeO3的成相过程.结果表明,在600℃煅烧可制备出高纯的BiFeO3纳米颗粒.同时发现,随着双丙烯酰胺含量的增加,所得样品晶粒尺寸逐渐减小,从而制备出平均粒径约52～110nm的系列BiFeO3颗...     

制备方法对双介孔钴基催化剂结构及其费-托反应性能的影响

以双介孔分布MCM-41分子筛为载体,采用等体积浸渍、氨水气相诱导水解和过量浸渍法制备了费-托合成钴摹催化剂,并考察了它们的孔结构、活性物种分布及费-托合成催化性能.结粜表明,采用等体积浸渍法和氨水气相诱导水解法制备的催化剂都保持了较好的双介孔特性,Co颗粒人部分位于分子筛的孔道内部.过量浸渍法和等体积浸渍法制备的催化...     

乙酰胺-氯化锌新型离子液体的合成及物化性质

合成了CH3CONH2-ZnCl2体系离子液体;利用红外光谱仪分析了CH3CONH2-ZnCl2离子液体的化学特征,采用步冷曲线法绘制了CH3CONH2-ZnCl2二元体系熔点图,测定了其物化性质.结果表明,CH3CONH2-ZnCl2二元体系的最低熔点为8℃;当CH3CONH2与ZnCl2的摩尔比为3:1时,Zn2+...     

Effect of chenodeoxycholic acid (CDCA) additive on phenothiazine dyes sensitized photovoltaic performance

The effects of chenodeoxycholic acid (CDCA) in a dye solution as a co-adsorbent on the photovoltaic performance of dye-sensitized solar cells (DSSCs) based on two organic dyes containing phenothiazine and triarylamine segments (P1 and P2) were investigated.It was found that the coadsorption of CDCA can hinder the formation of dye aggregates and improve electron injection yield and thus Jsc.This has also led to a rise in photovoltage,which is attributed to the decrease of charge recombination.The DSSC based ...     

中医药膳防治复发性阿弗他溃疡

通过近年来有关中医药膳防治复发性阿弗他溃疡的研究,从中西医角度论述了复发性阿弗他溃疡的发病机理,挖掘出有效防治复发性阿弗他溃疡的中医药膳,总结了中医药膳的功能成分如何作用于复发性阿弗他溃疡,归纳了可行的中医药膳调理的方法和应用原则,为开展药膳干预复发性阿弗他溃疡发病提供理论基础.     

离子液体添加剂[BMIM]HSO4对锌电积过程析氧反应动力学的影响

研究了1-丁基-3-甲基咪唑硫酸氢盐([BMIM]HSO₄)离子液体对锌电积过程析氧反应的影响. 研究工作借助于动电位极化, 电化学阻抗谱, 扫描电镜和X射线衍射等测试技术. 动电位极化曲线及对应的动力学参数分析表明, [BMIM]HSO₄对阳极析氧反应具有催化作用,可提高析氧反应速率常数. 电化学阻抗谱数据表明,[BMIM]HSO₄能显著降低阳极析氧电荷传递电阻,在所研究的1.85-2.10 V电位范围内添加5 mg·L^-1 [BMIM]HSO₄, 电阻值至少降低50%. 此外, 添加剂对阳极表面二次反应具有抑制作用, 其在阳极表面的吸附,阻碍了阴离子的阳极活化位点吸附过程. 电化学测试结果与长时间(120 h)阳极极化后所得阳极表面形貌和结晶取向分析结果相一致. [BMIM]HSO₄的添加能有效抑制中间产物β-PbO₂的形成,促进铅银电极表面大块且疏松多孔α-PbO₂的生成,加速阳极析氧的进行.     

Constructing Charge-Transfer Excited States Based on Frontier Molecular Orbital Engineering: Narrowband Green Electroluminescence with High Color Purity and Efficiency

The design and synthesis of organic materials with a narrow emission band in the longer wavelength region beyond 510 nm remain a great challenge. For constructing narrowband green emitters, we propose a unique molecular design strategy based on frontier molecular orbital engineering (FMOE), which can integrate the advantages of a twisted donor–acceptor (D-A) structure and a multiple resonance (MR) delayed fluorescence skeleton. Attaching an auxiliary donor to a MR skeleton leads to a novel molecule with twisted D-A and MR structure characteristics. Importantly, a remarkable red-shift of the emission maximum and a narrowband spectrum are achieved simultaneously. The target molecule has been employed as an emitter to fabricate green organic light-emitting diodes (OLEDs) with Commission Internationale de L'Eclairage (CIE) coordinates of (0.23, 0.69) and a maximum external quantum efficiency (EQE) of 27.0 %.