基于平面通量展开的三维Pin by Pin输运SP3计算

基于Pin by Pin输运SP3计算是下一代反应堆物理计算方法中一个重要的研究方向.节块法一般采用高阶通量和中子源展开以适应较大的节块尺寸,因此对于Pin by Pin计算来说效率偏低.由于反应堆堆芯不均匀性更多发生在径向,本文提出一种径向基于二维平面通量展开结合轴向常规节块法的综合方法进行三维Pin by Pin输...     

Production of COx-Free Hydrogen and Few-Layer Graphene Nanoplatelets by Catalytic Decomposition of Methane over Ni-Lignin-Derived Nanoparticles

Nickel (Ni)-lignin nanocomposites were synthesized from nickel nitrate and kraft lignin then catalytically graphitized to few-layer graphene-encapsulated nickel nanoparticles (Ni@G). Ni@G nanoparticles were used for catalytic decomposition of methane (CDM) to produce COx-free hydrogen and graphene nanoplatelets. Ni@G showed high catalytic activity for methane decomposition at temperatures of 800 to 900 °C and exhibited long-term stability of 600 min time-on-stream (TOS) without apparent deactivation. The catalytic stability may be attributed to the nickel dispersion in the Ni@G sample. During the CDM reaction process, graphene shells over Ni@G nanoparticles were cracked and peeled off the nickel cores at high temperature. Both the exposed nickel nanoparticles and the cracked graphene shells may participate the CDM reaction, making Ni@G samples highly active for CDM reaction. The vacancy defects and edges in the cracked graphene shells serve as the active sites for methane decomposition. The edges are continuously regenerated by methane molecules through CDM reaction.     

高效液相色谱切换波长法测定多组分体系

1引言目前植物激素常采用反相高效液相色谱法检测,但植物中激素等多种组分同时存在,单一波长不能使每个组分都在最佳检测波长下检测。本实验采用切换波长法对植物样品进行多组分检测分析,提高了检测灵敏度。采用反相高效液相色谱法(HPLC)同时测定油菜中的内源激素赤霉素(GA3)、     

聚丙烯/纳米级金红石型二氧化钛/聚烯烃弹性体复合材料的抗老化性能研究

采用TEM和UV-Vis等测试手段表征了金红石型纳米级TiO2和体相TiO2的性能特征;通过熔融共混法分别制备了PP/纳米级TiO2/POE和PP/体相TiO2/POE复合材料,采用GB/T16422·2-1999所述的塑料实验室光源暴露实验方法,用氙灯气候试验机对纯PP和复合材料进行28天人工加速老化.结果表明,二氧化钛粒子在PP/POE基体中分散性良好,而纳米粒子对PP/POE基体具有增韧作用;改性后的两类复合材料均具有优异的抗老化性能,而PP/(1·0wt%)纳米级TiO2/POE复合材料的抗老化性能更加优异,其加速老化28天后的无缺口冲击强度达到80·45kJ·m-2,比纯PP提高4倍多,而同期加速老化28天后的PP/(1·0wt%)体相TiO2/POE复合材料的无缺口冲击强度只有47·88kJ·m-2;对纯PP老化过程中的羰基指数和冲击性能的变化情况进行了分析,发现二者近似成线性关系,其相关系数r在0·9以上.     

高效液相色谱-质谱法测定沙田柚果肉汁中的呋喃香豆素类化合物

采用反相高效液相色谱法,以C18硅胶柱为色谱柱,甲醇-水（含0.1%HAc）为流动相     

A NEW KIND OF FIBER-SPUN FROM POLYSULFONAMIDE/ZINC SOLUTION

In this paper, we succeed in fabricating high-temperature fiber of polysulfonamide/ZnO. Polysulfonamide/ZnO nanocomposite was prepared by in-situ polymerization. Some studies and characterization of Polysulfonamide/ Zinc oxide nanocomposite with ZnO 0.5% have been done. It includes ηr,, Crystal degree and thermal property. Experiment＇s results showed that, ZnO as filler can improve crystal degree of polysulfonamide fiber. The crystal degree has been bnproved, from lower than 20% up to 27%. ηr of polysulfonamide/ Zinc oxide nanocomposite solution with ZnO 0.5% is 2.03. The maxinum weight loss of the nanocomposite occurred at 453.5 ℃.     

甲基丙烯酸3-磺酸钾丙酯-苯乙烯共聚物与N,N,N-三甲基十六烷基溴化铵相互作用研究

两亲分子由于具有自组装性质,如表面活性剂分子自组装形成胶束,囊泡,天然的磷脂分子自组装形成脂质体,继而参于生物膜的形成,这是大家所熟悉的．高分子两亲分子尤其是两亲性两嵌段高分子具有自组装性质,并形成规整性好的聚集体［１～３］．聚电介质 表面活性剂体系...     

甲基丙烯酸3—磺酸钾丙酯—苯乙烯共聚物与N,N,N—三甲基十六烷基化铵相 …

两亲分子由于具有自组装性质,如表面活性剂分子自组装形成胶束,囊泡,天然的磷脂分子自组装形成脂质体,继而参于生物膜的形成,这是大家所熟悉的．高分子两亲分子尤其是两亲性两嵌段高分子具有自组装性质,并形成规整性好的聚集体［１～３］．聚电介质表面活性剂体系...     

丝网印刷法制备高催化活性对电极

对电极在染料敏化太阳能电池（DSCs）中主要起催化氧化还原反应及收集电荷的作用,铂对电极常用的制备方法为磁控溅射法,但其成本较高,制备条件苛刻. 本文通过引入低成本的表面活性剂Span-85,所制得的铂对电极的附着力、透光率和均匀性显著改善,实现了面积可控,与两步浸泡法和旋涂热解法制备的对电极在DSCs中的光电转换效率分别为7.30%,6.96%和7.03%. 紫外-可见吸收光谱、扫描电镜和附着力测试等结果表明,（1）添加表面活性剂有利于增加附着力及改善透光率和均匀性;（2）使用该法制备的Pt/FTO对电极的透光率与两步浸泡法制作的相同,且铂粒子分布更加均匀. 电化学阻抗图谱、塔菲尔极化曲线和循环伏安曲线结果表明,丝网印刷方法制备的Pt/FTO对电极具有更加优异的催化性能,且该法更有利于降低其生产成本和大规模生产.     

热扩散法制备MoO3/SiO2催化草酸二甲酯和苯酚酯交换反应

采用热扩散法（TS）和等体积浸渍法制备了MoO₃/SiO₂催化剂用于草酸二甲酯和苯酚酯交换反应.结果表明,热扩散法制备的10%MoO₃/SiO₂-TS催化剂较等体积浸渍法制备的10%MoO₃/SiO₂-C催化剂具有更好的催化性能.运用X射线衍射、Raman光谱、X射线光电子能谱分析、吡啶吸附红外光谱、NH₃程序升温脱附等手段对催化剂进行了表征,发现虽然两种方法制备的催化剂都只有弱Lewis酸中心,钼均以氧化钼单体形式存在,未形成解离和聚合,但是10%MoO₃/SiO₂-TS催化剂较10%MoO₃/SiO₂-C催化剂表面钼含量更高且MoO₃分散得更好.在苯酚用量为0.2mol,10%MoO₃/SiO₂-TS催化剂用量为1.2g,反应温度为180℃,草酸二甲酯与苯酚的摩尔比为2,反应时间为4h的优化条件下,苯酚转化率可达70.9%,甲基苯基草酸酯和草酸二苯酯的收率分别达63.1%和7.7%.