The effects of dilution gas on nanoparticle growth in atmospheric-pressure acetylene microdischarges

A two-dimensional multi-fluid model is developed to investigate the effects of dilution gas on microplasma properties and nanoparticle behavior in atmospheric-pressure radio-frequency acetylene discharges. The percentage of dilution gases (argon and helium) percentage varied from 0% to 90%, with the pressure kept constant. Simulation results show that the dilution gas percentage has a significant influence on the spatial distributions of the electron density and temperature, as well as on the formation of nanoparticles in acetylene microplasmas. With increasing dilution gas percentage, the electron density profile changes continuously from being high at the edge to high in the center. A mode transition from a mixed discharge mode with both α regime and drift-ambipolar regime into α regime occurs, which is associated with a sudden decrease in the electron density of the presheaths and an increase in the electron temperature of the bulk plasma. The mode transition point corresponds to the lowest number density ratio of hydrocarbon ions to acetylene. The highest number density ratio is observed at a dilution percentage of 90%, and causes more effective nucleation and coagulation of nanoparticles. Furthermore, owing to the high ionization potential of helium, the transition point moves to a larger dilution gas percentage in ${{rm{C}}}_{2}{{rm{H}}}_{2}$/He microplasmas. Finally, the growth of nanoparticles via coagulation is studied.     

亚麻织物耐日晒整理的研究

日晒牢度是纺织品色牢度中的一项重要指标。通过对亚麻织物采用表面活性剂处理，然后使用在常规染色中日晒牢度较低的染料——活性嫩黄K-46进行染色，再与常规染色的亚麻织物进行日晒牢度的对比，摸索出了一种兼顾环保、节能的染色工艺。     

One-pot synthesis of Cu-Ce co-doped SAPO-5/34 hybrid crystal structure catalysts for NH_3-SCR reaction with SO_2 resistance

SAPO-34,SAPO-5/34 based catalysts doped with Cu,Ce as active components were synthesized via a one-pot hydrothermal method by using different amounts of additive(a-cellulose),and their catalytic activities were measured for selective catalytic reduction(SCR) of NO with NH3.The synthesized Cu-Ce co-doped products switch from cubic SAPO-34,to flower-like aggregated SAPO-5/34,hybrid crystal SAPO-5/34,and finally to spherical aggregated SAPO-34 with the increase of α-cellulose amount.The Cu-Ce co-doped SAPO-5/34 hybrid crystal structure catalysts with 0.75 mol ratios of C/P(Cu-Ce/SP-0.75)exhibit excellent NH3-SCR activity with higher than 90% NO_x conversion in the temperature range of 180-450℃,at WHSV of 20000 mL/(g·h).Furthermore,the catalyst displays outstanding sulfur resistance and NO_X conversion maintains above 90% at 200-450℃ after adding 100 ppm of SO_2.The characteristic results suggest that the high deNO_X performance of Cu-Ce/SP-0.75 is due to the enhanced accessibility,abundant activity species,excellent redox property and high adsorptive and activated capacity for NH3.     

Keggin型P-V-Mo-W四元杂多酸催化合成乙酸正丁酯

采用正交试验设计研究了Keggin型P-V-Mo-W四元系列杂多酸H4PVMoxW11-xO40·nH2O(x=1,2,3,4)催化冰乙酸和正丁醇合成乙酸正丁酯的反应,得出最佳反应条件如下:正丁醇与冰乙酸的物质量比为1.2∶1,催化剂的用量为冰乙酸质量的0.5%,反应时间为40 min,酯化率达到88.52%。该系列杂多酸的酯化率随钨原子数的增加而提高。     

金属酞菁负载分子筛对孔雀石绿的降解

采用浸渍法制备了4种负载型金属酞菁催化剂：MCM-41-a-（GH11O）4PeCo（Ⅱ）[Ni（Ⅱ）、Cu（Ⅱ）、Zn（Ⅱ）]。并在室温（25±1℃）中性以及可见光条件下,考察了上述催化剂中心金属、催化剂用量、H2O2浓度以及重复利用方面对孔雀石绿降解速率的影响。研究结果表明：4种催化剂均具有良好的催化性能,在相同条件下,MCM-41-a-（C3H11O）4PcCo的催化效果最好,并且其浓度在0．7g／L（质量为20mg）,H2O2浓度为10mmol／L条件下,孔雀石绿在10min内降解率可达92％。对重复性的研究表明该种负载催化剂具有良好的重复利用性。     

脂肪胺聚氧乙烯醚与LAS复配体系的表面活性

研究了脂肪胺聚氧乙烯醚（AE18）和十二烷基苯磺酸钠（LAS）在水溶液中相互作用。通过表面张力法测定了AE18和LAS不同比例下的临界胶束浓度（CMC）。两种表面活性剂以任何比例复配时,复配体系的CMC都明皿低于LAS的CMC;并且在摩尔比n（LAS）：n（AE18）=1：9时,混合体系的CMC比任何单一表面活性剂CMC都低。复配体系达到CMC时的表面张力（γCNC）介于两种表面活性剂之间。运用Clint提出的理想混合胶团公式对CMC值进行了计算,与CMC实验值比较．发现随AE18摩尔分数的增加,CMC的实验值与计算值相近。     

阳离子聚合物复合膨润土对活性染料染色废液的脱色效果初探

用2种阳离子聚合物复合膨润土来对活性染料染色后的废液进行脱色,用分光光度法测定脱色率,研究了复合膨润土中阳离子聚合物的含量、活性染料废液的pH值、温度对脱色效果的影响。结果表明：GTA复合膨润土中GTA质量百分数为30％,DMA复合膨润土中DMA的质量百分数为40％时,对活性染料染色废液的脱色率最大;中性或者偏碱性的条件比较适合两种阳离子聚合物复合膨润土对活性染料废液的脱色;DMA复合膨润土在活性染料废液温度为40℃时脱色效果最好,而GTA复合膨润土在50℃时脱色效果最好。     

一种基于电子测量带宽500MHz以下数字示波器脉冲频谱分析

对基于电子测量带宽500MHz以下数字示波器的视频测试、嵌入式系统、射频测试进行了研究,通过实例着重进行了脉冲频谱分析。     

羟基喜树碱联合丝裂霉素诱导人白血病K562细胞凋亡

观察羟基喜树碱与丝裂霉索联合应用对人白血病细胞K562的作用效果,并探讨其机制。不同浓度羟基喜树碱与丝裂霉素单独及联合作用于人白血病细胞K562后,应用台盼蓝拒染法检测细胞生长抑制率,计算合用指数（CI）,流式细胞仪（FCM）检测K562细胞凋亡率,吖啶橙（AO）荧光染色和透射电镜观察凋亡形态学变化。结果表明：单独应用时羟基喜树碱和丝裂霉素的IC50分别是8μ/mL和12．5μg/mL,联合应用时IC50下降为4μg/mL（HCPT）和3．6μg/mL（MMC）,CI=0．78,为协同效应。羟基喜树碱与丝裂霉素单独及联合应用均可诱导K562细胞凋亡。2种药物联合应用时的凋亡率高于各自单独用药。羟基喜树碱与丝裂霉素联合应用可以通过共同诱导细胞凋亡。协同抑制人白血病细胞生长。     

玉米须化学成分研究

将干燥玉米须水煮提取,提取液依次用乙酸乙酯和正丁醇萃取,制得乙酸乙酯和正丁醇提取物,用硅胶柱层析进行分别分离两种提取物得到4个化合物,依据理化性质及波普数据分析,分别鉴定它们的结构为：香草醛（1）、硬脂酸（2）、尿囊素（3）和邻苯二甲酸二异辛酯（4）。其中,化合物1和3为首次从该植物中分离得到。