Luminescent Cu(I) and Ag(I) coordination polymers: Fast phosphorescence or thermally activated delayed fluorescence

By applying two donor-acceptor motif molecules, 5,10-di(pyridin-4-yl)-5,10-dihydrophenazine (L1) and 10,10'-di(pyridin-3-yl)-10H,10'H-9,9'-spiroacridine (L2), as ligands and CuI/AgCF₃CO₂ as metal salt, we synthesized three coordination polymers, namely, {Cu₄(L1)₂I₄} (CP1), {Cu(L2)I·CHCl₃} (CP2) and {Ag(L2)CO₂CF₃·CHCl₃} (CP3). X-ray crystallographic analysis revealed that three coordination polymers all feature one-dimensional (1D) linear chains which are consisting of molecular boxlike units. In comparison with low photoluminescence quantum yield (PLQY) of two ligands, three coordination polymers, CP1, CP2 and CP3, present more intense photoluminescence with PLQY of 15%, 46% and 34% at room temperature respectively. The PL emission of CP1 and CP2 at room temperature could be attributed to the fast phosphorescence with lifetime both around 5 μs due to effective intersystem crossing (ISC). Whilst, it is worth noting that CP3 exhibit thermally activated delayed fluorescence (TADF) emission at room temperature.     

Cholesterol-based simple supramolecular gelators: an approach to selective sensing of CN− ion with application in dye adsorption

Cholesterol-linked simple supramolecular gelators 1–3 with functional diversity have been designed on 4-hydroxybenzaldehyde backbone for anion sensing through gel-to-sol methodology. Change in functional group in the gelators of common structural feature has significant impact on gelation, gel properties, morphology and anion sensing behavior. The dicyanovinyl derivative 3 has been established as superior gelator among the three as it forms gel from varieties of solvents with lowest concentration. All the three gels are applied in anion recognition. The gel state of 1 remains virtually intact in presence of all the anions tested. The oxime derivative 2 interacts with basic anions like CN^?, F^? and AcO^? and displays no selectivity in gel phase anion sensing. On contrary, the dicyanovinylated analogue 3 shows gel-to-sol transition selectively in presence of CN^? and validates its visual sensing. Additionally, the gel of 3 as explored in dye adsorption works well in rapid removal of crystal violet, a cationic dye from waste water.     

不同活性炭负载的镍基催化剂上废塑料裂解制碳纳米管性能

以椰壳炭、竹炭和木炭三种活性炭为载体,采用浸渍法制备炭负载金属镍的催化剂,考察其在废塑料裂解制备碳纳米管过程中的催化反应性能;采用X射线衍射、扫描电镜、透射电镜、拉曼光谱仪、同步热分析仪、比表面积分析仪等手段分析了催化剂和产物碳纳米管的形貌和结构。结果表明,椰壳活性炭为载体制备的镍基催化剂上碳纳米管产量最高、石墨化程度最好。以椰壳活性炭为载体制备的镍基催化剂为例,研究了反应温度和镍负载量对其催化性能的影响。     

基于BP神经网络的城镇污水厂活性炭自动投加系统研究

近年来,活性炭吸附技术逐渐成为深度处理的主流技术,但粉末活性炭投加系统仍处于人工控制阶段,现场需要技术人员依靠经验确定活性炭投加量,易造成出水水质不稳定、活性炭药耗大等问题.以浙江省嘉善县某城镇污水处理厂的深度处理工艺为研究背景,以粉末活性炭投加系统为研究对象,针对活性炭投加控制系统滞后、非线性、复杂等问题,建立了BP神经网络前馈预测-PID反馈控制的自动投加控制系统.实践证明,该系统具有较强的自适应能力和较高的控制精度,出水COD达标率较人工控制提高了8.88%,活性炭日均消耗量削减了16.61%,取得了较好的经济效益.     

稻壳基活性炭对锰酸锂电池倍率性能的影响

稻壳基活性炭(RH-AC)具有天然的多级孔道结构,是由稻壳碳化和活化两步得到的。 用RH-AC和锰酸锂(LMO)混合制备复合电极,以锂片为对电极,组装半电池进行恒流充放电测试。 实验发现:含有质量分数为5%的RH-AC与90.5%的LMO的复合电极(RH-AC5)在5C电流密度循环100圈后比容量为89.3 mA·h/g,容量保持率高于89%,远优于纯锰酸锂电极。 采用循环伏安法计算出的锂离子扩散系数,及利用交流阻抗测试拟合后得到的结果进一步验证了该结论。     

柔性共面超级电容器电极印制及性能

 柔性全固态超级电容器作为便携式、可穿戴电子的储备电源备受青睐。利用印刷电子大面积、柔性化的独特优势可大大简化柔性电极的制作工艺,以活性炭为活性材料配制油墨,并结合导电银浆,采用丝网印刷方式套印制作了柔性超级电容器电极,并将PVA-H₂SO₄凝胶作为电解质涂覆在活性电极上组装成柔性共面超级电容器,测试其电化学性能。结果表明,丝印柔性超级电容器电极可成功应用于柔性共面超级电容器。当采用PVA-H₂SO₄凝胶作为电解质时工作电压可达0.8 V。当充放电电流为0.2 mA时,柔性共面超级电容器的面积比电容达到18 mF·cm^-2。     

循环活性污泥复合生物反应器废水处理技术及其评价

介绍了循环活性污泥复合生物反应器废水处理技术的工艺原理和组成、国内外类似研究的现状及进展情况,对循环活性污泥复合生物反应器废水处理工艺的主要技术特征、优点及其经济性进行了分析与评价.     

电化学活化玻碳/铋膜电极制备及铅、镉离子敏感分析法

以电化学活化玻碳为基底电极原位制备金属铋膜电极,用之于分析Pb2+、Cd2+.方法如下:在氢氧化钠溶液中,由恒电位或循环扫描电位方法活化玻碳电极,随后以稀盐酸替代传统的醋酸缓冲液作为分析溶液将Bi3+与Pb2+、Cd2+共沉积在活化玻碳电极表面,再以方波阳极溶出分析法(SWASV)检测金属离子.结果表明:经简单的电化学清洗步骤即可高重现地再生电极表面,大幅度提高检测Pb2+、Cd2+的灵敏度,检测范围也可拓展至高卤素离子含量的样品.     

Diffusion of n-Hexane in Porous Media of Activated Carbon

Kinetics of n-hexane oxidation on the surface of activated carbon was investigated at different temperatures. The diffusion step of this reaction was determined and estimated. The spatial structure of activated carbon was reconstructed using electron micrographs and measurements. The relation between this structure and diffusitivity of n-hexane was determined in the form of an intrication coefficient. Two currents of diffusion into the volume of activated carbon were ascertained. Relations between the intrication coefficient and the topology of the intricated space are suggested.     

快速反应动力学中的停流法

本文主要讨论快速反应动力学中停流法的基本原理及其应用,同时重点讨论了用高压下的停流法来研究N-甲基-5,10,15,20-四苯基卟吩在N,N-二甲酰胺中的金属化作用。