石墨烯/纳米TiO_2复合材料的制备及光催化还原性能

为探索超声辅助下利用紫外光及耦合热还原工艺制备RGO/纳米TiO_2复合材料的方法,并对其在缺氧水体中的光催化还原特性进行研究,首先,以鳞片石墨为原料,采用改进的Hummers法制备了氧化石墨烯(GO),进而通过超声/紫外光还原工艺制备了还原氧化石墨烯(RGO);然后,以钛酸丁脂和RGO为前驱物,采用溶胶-凝胶法并在氮气保护下高温加热制备了RGO/纳米TiO_2复合光催化材料;接着,利用FTIR、XRD、BET及紫外-可见光谱等对RGO/纳米TiO_2复合材料进行了结构性能表征;最后,以2,4-二氯苯氧乙酸(2,4-D)为探针物,研究了RGO/纳米TiO_2在缺氧水体中的光催化特性与2,4-D降解机制。结果表明:采用低温氧化Hummers法制备的GO六碳环上生成的活性基团较少,采用超声/紫外光还原工艺及耦合高温热还原工艺可使环状结构得到良好的修复;所制备的RGO/纳米TiO_2复合材料具有良好的2,4-D降解能力,在缺氧状态下,2,4-D主要发生光催化还原反应,脱除苯环上的氯,产生氯酚、邻苯三酚及间苯三酚等中间产物,部分2,4-D被氧化降解生成CO_2和H_2O。制备的RGO/纳米TiO_2复合材料具有良好的光催化还原性能。     

Chemical structure and catalytic activity of quaternary onium salt‐type triphase catalysts based on CPS microspheres

In this work, diversified quaternary onium salt‐type triphase catalysts (TPC) were prepared based on crosslinked polystyrene (CPS) microspheres, and the relationship between their chemical structures and catalytic activities in liquid‐solid‐liquid reaction system were investigated in depth by using the esterification reaction of benzyl chloride with sodium acetate as a model system. The experimental results indicate that the chemical structures of the TPC affect their catalytic activity greatly and there are four basic points: (1) the quaternary phosphonium‐type TPC have higher activity than quaternary ammonium‐type catalyst; (2) the TPC with more lipophilic substitutes at N atom have higher catalytic activity; (3) the TPC with longer spacer arm, which links quaternary onium salt group to the matrix microsphere, have higher catalytic activity; (4) the bonding density of quaternary onium salt group on the polymeric carrier affects the hydrophilic and hydrophobic property of the TPC, and consequently, influences the catalytic activity significantly. For a given triphase catalysis system, there is an optimal bonding density of quaternary onium salt group on the solid catalysts. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

鄂尔多斯盆地延长组7段致密油地质工程一体化解决方案——针对科学布井和高效钻井

鄂尔多斯盆地陇东地区长7致密油储层主要为重力流砂体沉积,砂体的分布在垂向和横向上均复杂多变,单砂体厚度薄,对高效钻井和生产提出了挑战。文章提出了一套利用近钻头随钻测量技术等多学科知识相结合的地质工程一体化方法。在综合地质研究的基础上,建立三维精细地质、油藏和地质力学模型,进行钻井位置优选、工厂化平台设计、钻井作业实施和地质导向方案优化,使井轨迹设计科学合理,钻井过程中提高砂体钻遇率,同时保证后期生产阶段较高的单井产量与井区的最终长期累计产量。研究结果表明:研究区的优质储层主要为碎屑流的块状砂岩,提高钻遇率的核心在于利用实时传输随钻测量数据,综合分析钻、测、录数据,确定钻头在沉积旋回的位置,从而确定地质导向作业方案。在该方法指导下实施的两口水平井钻井作业,油层钻遇率较周边井钻遇率提高5%~10%;通过早期基于地质模型和地质力学模型基础上的数值模拟,结合钻井和生产实践科学布井,最终选定400m为研究区最佳水平井井距。     

炭黑改性及对水性聚氨酯涂膜导电性的影响

采用原位乳液合成法,以炭黑（CB）为芯材、聚氨酯(PU)为壁材,制备表面均匀包覆聚氨酯的改性炭黑粒子（CB-PU）,通过FTIR、TG、SEM、EDS等表征了改性前后粒子的结构和形态;对粒子进行分散性试验,结果表明,CB-PU在水中的均匀分散性与稳定性相比CB明显提高;将改性前后粒子与水性聚氨酯（WPU）涂料复合得到不同CB含量的导电涂料（CB/WPU、CB-PU/WPU）,经涂覆、烘干得到导电膜材。研究结果显示,由于均匀包覆的壳层聚氨酯的亲水性,CB-PU能较为均匀地分散在WPU涂膜中;同时,由于CB-PU在涂膜中分散性的提高,极大地增大了涂料中导电粒子的网络密度和网络强度,CB-PU/WPU涂膜的导电性能显著提高;当保持体积电阻率约为3.3×103 Ω•cm时,CB质量分数由CB /WPU涂膜中的12 wt%下降到CB-PU/WPU 涂膜中的6 wt%;研究表明,通过在CB表面均匀包覆基体树脂层,可有效改进CB在基体中的分散性以及促进其导电网络形成。涂膜力学测试表明,添加改性后CB的涂膜断裂伸长较CB更优异,而强度有所下降。     

Protein arrays based on biotin-streptavidin system for the simultaneous detection of TORCH infections

In this paper, we developed a protein array based on biotin-streptavidin system (PABS) used in the identification of IgM antibodies against TORCH antigens, including toxoplasma gondii (TOX), rubella virus (RuV), cytomegalovirus (CMV) and herpes simplex virus types II (HSV-2) antigens. The detection signal intensities and sensitivities between the PABS and the direct labeling array system (DLAS) were compared. The linear ranges of detectable IgM antibodies in PABS were 0.485-1000 microg/mL, which was more sensitive than DLAS. Quantitatively, the lowest detectable amount for IgM antibodies on each spot of the PABS was 0.25 pg. Furthermore, sixty serum samples from patients were tested with the PABS in TORCH detection. All the results were correspondingly confirmed with ELISA assay. No significant differences in identifying TORCH specific IgM antibodies were found between the PABS and ELISA assay. There was a good concordance between PABS and ELISA in the classification of sera. The results suggested that the PABS was more sensitive, sample-saving and suitable for multi-pathogens parallel clinical detection.     

弹性阻尼金属螺旋丝网夹芯结构连接工艺及力学特性

针对弹性阻尼螺旋金属丝网夹芯结构界面连接性能不明确的问题,分别采用真空钎焊和胶结两种典型连接工艺,进行了面内压缩和拉伸剪切力学性能试验,结合SEM和EDS等材料微观表征方法,展开夹芯结构界面结合的物理机制和力学特性的研究.研究结果表明:钎焊连接界面相对胶结更均匀连续,钎料中Ni、Si元素与芯材、面板中的Fe、Cr元素扩...     

基于DM9000网口芯片的DSP6713B网口扩展

网口在很多硬件板上已经被广泛运用。针对DSP6713B没有自带的网口问题,提出一种基于DM9000网口芯片扩展网口的方案。在该方案中,解决了DM9000网口芯片的驱动问题,完成了LWIP网口通信协议移植,实现了DSP6713B与PC机的TCP通信。实验结果证明,所提出的方案稳定、可靠。     

HPLC-ELSD法测定酶解磷脂中甘油磷脂酰胆碱含量的研究

本研究建立了高效液相色谱-蒸发光散射法酶催化水解磷脂样品中的甘油磷脂酰胆碱(GPC)的方法。检测条件为:使用Alltech Silica色谱柱(4.6 mm×250 mm,5μm),柱温40℃,甲醇为流动相,流速1.0 mL/min,蒸发光散射检测器漂移管温度65℃,空气流速1.7 L/min。GPC为最后出峰的强极性组分,其保留时间为4.97 min,所得GPC标准曲线为Y=2.048 3 X+7.774 4,线性相关系数R2为0.991 4。检测限为6.3μg/mL(S/N=3),定量限为13.0μg/mL(S/N=10)。GPC的平均加标回收率为102.5%,RSD是2.2%(n=3),分析时间小于6 min。结果表明本方法分离效果好,检测结果准确、稳定,适用于酶催化水解磷脂样品中甘油磷脂酰胆碱的定量测定。     

桃杏复合低醇果醋饮料的研制

本文以桃、杏为原料,采用液态深层发酵生产工艺,经酒精发酵和不完全醋酸发酵酿造出果香浓郁的复合低醇果醋,最后经调配制成营养保健型低醇果醋饮品。