二肽类膦酸酯衍生物的合成与抗肿瘤活性

为了寻找抗肿瘤活性化合物,以前期研究的含一个氨基酸结构单元的膦酸酯衍生物为基础,设计合成了15个二肽类膦酸酯衍生物(Ⅲa-Ⅲo).采用溴化噻唑蓝四氮唑(MTT)法进行体外抗肿瘤活性测试.结果表明:该类化合物对人肺癌细胞(A-549)、人胃癌细胞(SGC-7901))和人食管癌细胞(EC-109)有潜在增殖抑制作用.其中...     

碳纳米纤维负载Co3S4复合材料的合成及其在染料敏化太阳电池对电极的应用

采用水热法合成四硫化三钴（Co₃S₄）催化材料,并利用球磨和喷涂技术将其制备成对电极,结合新型无碘电解液Co²⁺/Co³⁺用于染料敏化太阳电池（dye-sensitized solar cells,简称DSCs）来研究其光电性能。测试结果显示,基于Co₃S₄对电极,DSCs的能量转化效率（power conversion efficiency,简称PCE）只有6.06%,远远低于Pt对电极（8.05%）。为了提高Co₃S₄的催化能力,采用静电纺丝技术制备碳纳米纤维（electrospun carbon nanofibers,简称ECs）,结合水热法制备出不同负载量的碳纳米纤维负载四硫化三钴（Co₃S₄/ECs）复合催化材料用于对电极,结果表明,Co₃S₄/ECs的PCE最高可达（8.22±0.08）%,优于Pt对电极。     

氢、氟原子边缘修饰β-GeSe纳米带的第一性原理研究

采用第一性原理计算方法研究了二维β相GeSe的电子结构,通过对二维单层β-GeSe剪切得到一维β-GeSe扶手椅型纳米带.研究不同带宽(N=1-5)β-GeSe扶手椅型纳米带的几何结构和电子性质,发现不同带宽纳米带能带带隙不同,带隙总体上随着带宽减小,而纳米带直接带隙半导体性质不受带宽影响.通过使用H、F原子对GeSe扶手椅型纳米带边缘修饰,H原子修饰纳米带导致能带类型从直接带隙向间接带隙的转变.在费米能级附近处F原子各轨道对价带和导带贡献比H原子各轨道贡献多,在边缘修饰中纳米带对F原子更加敏感.未修饰和使用H原子修饰纳米带在可见光范围内没有吸收峰,用F原子修饰纳米带在可见光范围内出现吸收峰.研究表明可以通过边缘修饰调控纳米带光学特性.     

稀土元素对Mn/TiO2-PILC低温SCR性能影响研究

通过浸渍法制备了8%Mn/TiO₂-PILC以及稀土元素R（Ce,La）改性的8%Mn-2%R/TiO₂-PILC催化剂,考察了所制备催化剂的低温NH₃-SCR活性和抗水抗硫特性。结果发现,Ce的添加改变了催化剂的物相以及氧化还原特性,从而改变了催化剂的NO去除活性;稀土元素的添加可以减缓催化剂的失活速率,但是抗水抗硫特性仍然不理想。     

Solvent free synthesis of trifluoromethyl tertiary alcohols by cross Aldol reaction

Exceedingly fast preparation of trifluoromethyl tertiary alcohols has been accomplished from methyl ketones and trifluoromethyl ketones under solvent free conditions by cross Aldol reaction. The reaction was achieved in the presence of common inorganic base by grinding method at ambient temperature to give β-trifluoromethyl-β-hydroxyl ketones in high yields (up to 95%).     

<Superscript>63</Superscript>Ni schottky barrier nuclear battery of 4H-SiC

The design, fabrication, and testing of a 4H-SiC Schottky betavoltaic nuclear battery based on MEMS fabrication technology are presented in this paper. It uses a Schottky diode with an active area of 3.14 mm² to collect the charge from a 4 mCi/cm^{2 63}Ni source. Some of the critical steps in process integration for fabricating silicon carbide-based Schottky diode were addressed. A prototype of this battery was fabricated and tested under the illumination of the ⁶³Ni source with an activity of 0.12 mCi. An open circuit voltage (V _OC) of 0.27 V and a short circuit current density (J _SC) of 25.57 nA/cm² are measured. The maximum output power density (P _max) of 4.08 nW/cm² and power conversion efficiency (η) of 1.01% is obtained. The performance of this battery is expected to be significantly improved by using larger activity and optimizing the design and processing technology of the battery. By achieving comparable performance with previously constructed p–n or p–i–n junction energy conversion structures, the Schottky barrier diode proves to be a feasible approach to achieve practical betavoltaics.     

塔里木盆地8种有毒植物总生物碱的抗AChE活性

采用酸提碱沉、氯仿萃取法提取塔里木盆地8种有毒植物总生物碱,采用Ellman法,以他克林为阳性对照,探讨总生物碱抗AChE活性.实验结果表明8种植物中小花棘豆、盐角草、叉枝鸦葱、骆驼刺、苦马豆总生物碱具有明显乙酰胆碱酯酶抑制活性,黄香草木犀,盐生草,白茎盐生草的抑制率相对较低.     

种子生长法制备Au-Ag纳米花

以金纳米花为种子, 抗坏血酸和硝酸银混合物作为生长溶液制备了Au-Ag纳米花. 当Ag/Au的摩尔比从0增加到0.3时, 银可以在Au种子表面沉积, 得到的Au-Ag纳米花光谱在592~518 nm之间连续可调, 同时纳米花的枝长逐渐减小; 而当Ag/Au摩尔比大于0.3时, 还原的银出现自成核现象. 与Au纳米花相比, Au-Ag纳米花体现出了更好的Raman增强活性.