CoSOH/Co(OH)2复合纳米片的制备及其氧析出催化性能

以硝酸钴与硝酸锌为原料,加入尿素和氟化钠在反应釜120℃下均匀生长在碳纸上得到Zn-Co(OH)_2复合前驱体,通过在室温下用5 mol/L NaOH和1 mol/L Na_2S溶液将前驱体刻蚀并部分硫化合成了CoSOH/Co(OH)_2复合材料,考察其在电解水析氧反应(OER)中的催化性能。利用XRD、SEM、TEM、XPS对催化剂的微观结构及物理化学性质进行了表征。结果表明,该方法可以刻蚀Zn原子,留下氧空位并引入掺杂S元素,氧空位和S掺杂对OER反应起到积极促进作用。同时,非晶的CoSOH也有较好的OER活性。CoSOH与Co(OH)_2的协同作用使得材料表现出最优催化效果(过电位η=310 mV,塔菲尔斜率b=90 mV/dec)及长时间的电化学稳定性,具有较高的电催化产氧性能。     

大孔高镍LiNi0.8Co0.1Mn0.1O2正极材料的制备及其电化学性能研究

本工作以聚甲基丙烯酸甲酯(PMMA)微球组装成的胶晶模板作为铸模,溶胶-凝胶法辅助获得大孔LiNi0.8Co0.1Mn0.1O2 (NCM811)正极材料.结果 表明,利用PMMA作为造孔剂,形成了由100nm的颗粒堆积而成的大孔结构,这种结构有效地提高了材料的倍率性能和循环稳定性.大孔NCM811在0.1C的首次放电...     

ZnO超细纳米线阵列的制备及其电化学性能

以Zn(NO₃)₂· 6H₂O和C₆H₁₂N₄为原材料,采用二步水热法在碳纤维布上合成了形貌尺寸均匀的ZnO超细纳米线阵列。用 X 射线衍射(XRD)和扫描电镜(SEM)对其晶体结构和形貌进行了表征,利用恒流充放电测试等手段对其进行电化学性能测试。测试结果表明,材料表现出优异的电化学性能。在200 mA/g的电流密度下循环150次后,ZnO超细纳米线阵列仍然约有730 mAh/g的充放电比容量,库伦效率保持在95%以上。在1 200 mA/g的大倍率条件下,材料的充放电比容量依旧可达481 mAh/g左右,表现出十分良好的循环稳定性和可逆性能,是一种较为理想的锂离子电池负极复合材料。     

对可见光有良好吸收的新型烷基芴共聚物的合成、表征与性质

以芴为起始原料, 合成了两种主链含有芴酮及二腈基亚甲基芴结构单元的聚烷基芴光伏材料, 通过红外光谱和核磁共振谱对其进行了表征. 目标共聚物P1和P2的热分解温度分别为461.2和448.1 ℃, 玻璃化转变温度(Tg)分别为122.4和146.6 ℃, 具有良好的热稳定性. 在300~700 nm范围内, 该种材料对太阳光的吸收基本覆盖了整个可见光区域, 电化学分析得出其具有较好的氧化还原可逆性, 并且具有1.94和1.86 eV的相对较窄的能带宽度.     

甲基羟基铀酰离子与水的复分解反应

以醋酸铀酰为主要试剂, 在负离子检测模式下, 采用电喷雾串联质谱法制备了甲基羟基铀酰负离子. 实验发现, 气相中的甲基羟基铀酰离子与水分子发生分子离子复分解反应, 并用串联质谱法对反应产生的离子性产物进行了结构确认, 提出了反应的可能机理. 热力学计算结果表明, 该反应的ΔGReaction为-473.0 kJ/mol, ΔHReaction为-236.5 kJ/mol, ΔSSystem为0.792 kJ·mol-1·K-1. 该反应的速率常数为2.26 s-1.     

烟酰胺辅酶反应中心结构选择1,4-二氢烟酰胺的热力学和动力学根源

合成了对位取代的1-苯基-1,4-二氢烟酰胺和对位取代的1-苯基-1,2-二氢烟酰胺作为烟酰胺辅酶两种模型物, 分别测定了它们与N-甲基吖啶正离子反应热和活化吉布斯自由能. 通过对其热力学参数和动力学参数的比较发现, 虽然1,2-二氢烟酰胺辅酶模型物与吖啶正离子反应热力学驱动力大于相应的1,4-二氢烟酰胺辅酶模型物与吖啶正离子反应热力学驱动力, 但前者具有很高的活化熵, 从而导致其活化吉布斯自由能反而大于后者. 表明烟酰胺辅酶NADH反应中心结构在其氧化还原循环进化过程中选择1,4-二氢烟酰胺而不是1,2-二氢烟酰胺的根本原因是烟酰胺辅酶反应中心结构二氢吡啶环2位上的氢原子较4位上的氢原子有较大的空间位阻.     

Establishment of a Tumor-bearing Mouse Model Stably Expressing EGFP Labeled Human MUC1 VNTRs

Two eukaryotic vectors expressing 9 tandem repeats of human MUCI（VNTR）, VR1012-VNTR, and pEGFP-VNTR, were constructed by cloning VNTR gene into VR1012 and pEGFP, respectively. VNTR stably expressing murine Lewis lung carcinoma（LLC） cell line（VNTR^＋ LLC） was established by Lipofectamine-mediated transfection of pEGFP-VNTR into LLC cells. The EGFP expression was observed under a fluorescent microscope and VNTR expression in VNTR^＋ LLC cells was confirmed by means of Western blotting. A syngenic graft tumor model was generated by subcutaneous injection of VNTR^＋ LLC cells into C57/BL6 mice and tumor size increased rapidly with time and in a cell qumber dependent manner. VNTR mRNA expression in the tumor formed was confirmed by RT-PCR. After the third immunization mice were challenged subcutaneously with 5×10^5 VNTR^＋ LLC cells, a significant reduction of subcutaneous tumor growth was observed in the groups immunized with VNTR plasmid DNA compared with that in the groups immunized with the vector DNA alone. Thus, the suppression of subcutaneous tumor was antigen-specific. This model is useful for the development of tumor vaccines targeting MUCI VNTRs.     

First Total Synthesis of Hyacinthacine A6 from the Protected Derivative of Polyhydroxylated Pyrrolidine

（1S、2R、3R、5R、7aR）-1,2-Dihydroxy-3-hydroxy methyl-5-methylpyrrolizidine（hyacinthacine A6, I） was synthesized by Wittig＇s methodology via the reaction of aldehyde 6, prepared from the partially protected derivative of polyhydroxylated pyrrolidine, with appropriated ylides, followed by cyclization through the intemal reductive amination process of the resulting a,B-unsaturated ketone 7, and total deprotection.     

Catalytic Oxidation of NO over La_(0.8)Sr_(0.2)MnO_3 Perovskite

Catalytic oxidation of NO by O2 over La0.8Sr0.2MnO3 was tested in a tubular reactor.The reaction temperature ranged from 373 to 473 K,space time from 0.090 to 0.720 s,inlet NO concentration from 300 to 2000μL/L, and O2 volume fraction from 3%to 9%.The steady-state conversion of NO was increased significantly with increasing reaction temperature and the space time,slightly with increasing the O2 concentration but decreased with increasing the inlet NO concentration at a lower temperature.Under the conditions of 0.720 s space time,500μL/L NO concentration, 5%O2 volume fraction and 473 K,NO conversion reached 90%.A kinetic model including a network of 12 elementary reactions with the desorption of NO2 as the rate-limiting step is established and fits the experimental data well.The activation energy of NO2 desorption from the catalyst surface is determined to be 101 kJ/mol.     

Decomposition Reaction of Zn-MPA（3-Mercaptopropionic Acid） Complex Under Microwave Irradiation

The thermal decomposition of Zn-MPA complex was investigated under microwave irradiation. ZnO and ZnS nanocrystals could be obtained by decomposing Zn-MPA（3-mercaptopropionic acid） complex under different reaction conditions. It was found that both the pH value of the solution and the molar ratio of Zn2＋ and MPA can play an important role in the formation of ZnO and ZnS nanocrystals. MPA mainly acts as an S source or as a complexing agent. This study provides a new route for the controllable preparation of semiconductor nanocrystals.