改性纳米二氧化钛的探讨

用溶胶-凝胶法制备了掺有钼元素的二氧化钛溶胶,将它和没有掺杂的二氧化钛溶胶一起用紫外分光光度计扫描发现:掺杂的二氧化钛溶胶的吸收波段红移了。用均匀沉淀法制备的分别掺有硒、镧、铈的纳米二氧化钛,它们对甲基橙的降解能力依次降低,但与没掺杂的产品比较,其光催化降解能力都增强了。在掺杂量小于1%时,掺入硒效果最好。     

Catalytic graphitization of Mo-B-doped polyacrylonitrile （PAN）-based carbon fibers

A novel carbon fiber pretreatment was proposed. Polyacrylonitrile (PAN)-based carbon fibers were first anodized in H₃PO₄ electrolyte to achieve an active surface, and then coated with Mo-B catalysts by immersed the carbon fibers in a uniformly dispersed Mo-B sol. The as-treated carbon fibers were then graphitized at 2 400 °C for 2 h. The structural changes were characterized by X-ray diffractometry (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and high-resolution transmission electronic microscopy (HRTEM). The results show that much better graphitization can be achieved in the presence of Mo-B, with an interlayer spacing (d ₀₀₂) of 0.335 8 nm and a crystalline size (L _c) of 28 nm.     

麸皮中植酸酶的研究

经研究采用最优的提取工艺，1kg麸皮可以得到活力为2.7×106u／g的粉末状植酸酶7g，分别在不同的温度和pH值条件下测定此植酸酶的活力，得到它的最适温度和pH值分别为55℃和5.2，米氏常数为3.3×10(-4)mol／l。用此麸皮植酸酶催化水解米糠植酸盐，植酸磷的水解率高达99.95％。     

Pt/CNT修饰的TiO2纳米管在甲醇催化氧化中的应用

为了开发TiO2纳米管在电化学中的应用,该文制备了Pt/CNT/TiO2复合电极,研究其作为高效绿色新能源电极材料的应用.以300nm长的TiO2纳米管阵列为基底,聚乙二醇6000为碳源,镍为碳的催化剂,使无序的碳纳米管(CNT)生长在TiO2纳米管阵列的表面,呈现出多孔网络状结构.在CNT/TiO2复合纳米管上应用恒电流法沉积Pt纳米颗粒,使之高度分散在TiO2纳米管的表面.该复合材料具有很好的吸附性和导电性,是一种性能优异的甲醇催化氧化反应(MOR)的新阳极材料.当Pt的负载量为50.52μg cm-2,MOR电流密度高达178.2 mA,获得了良好的催化效率.     

无标记纳米金传感显色测定五氯苯酚

该文基于纳米金(AuNPs)颜色随盐致聚集而变化的特点,发展了测定五氯苯酚的无标记纳米金传感显色法。金纳米粒子在一定浓度盐的作用下发生团聚,而单链DNA(ssDNA)可以吸附在金纳米粒子表面保护金纳米粒子不团聚。羟基自由基能破坏ssDNA的结构,使其丧失对金纳米粒子的保护功能。该文利用PCP可以消耗羟基自由基,保护ssDNA,从而保护金纳米溶胶的稳定性,实现对PCP的测定。     

用于挥发性有机气体测定的化学阻抗传感器

该文以碳粉掺杂的聚合物为敏感膜,以叉指电极为基底制作了测定挥发性有机气体的化学阻抗传感器.当敏感膜吸附有机气体时,敏感膜膨胀,导致膜中导电性的碳粉粒子距离增加,电阻也增加.同时.有机气体的吸附还引起敏感膜的介电常数改变,从而导致电阻、电容改变.通过传感器电阻电容的变化可以实现有机气体的定量测定.考察了敏感膜厚度、敏感膜中碳粉含量、及测定频率对传感器电阻电容响应的影响.该文还探讨了电阻和电容响应的机理.     

多层纳米银／壳聚糖膜用于芘的表面增强拉曼测定

多环芳烃类物质的高疏水性质使得其在金属表面吸附能力差,从而拉曼增强信号弱。该文针对此问题,制备了以壳聚糖为骨架,纳米银颗粒为热点的多层纳米银／壳聚糖复合膜表面拉曼增强基底,成功用于芘的表面增强拉曼检测。由于壳聚糖本身的富集作用,目标分子被吸附、富集于银纳米颗粒形成拉曼热点,可检测0．01μmol／L的芘。     

铜和硼化物对PAN基炭纤维的催化石墨化作用

将单质铜、硼酸、PAN基炭纤维进行混合研磨,经过石墨化炉高温处理,利用X射线衍射检测了铜和硼在热处理过程中的变化,研究催化剂的量和热处理温度对石墨化度的影响,结果显示炭纤维的石墨化度由25.6%提高到95.6%,表明铜和硼化物二元催化剂体系要比一元催化剂体系铜或硼更能显著地提高PAN基炭纤维的石墨化度,并完善炭纤维的石墨晶型。     

Effect of anodization on the graphitization of PAN-based carbon fibers of PAN-based carbon fibers

One-step pretreatment,anodization,is used to activate the polyacrylonitrile (PAN)-based carbon fibers instead of the routine two-step pretreatment,sensitization with SnCl2 and activation with PdCl2.The effect of the anodization pretreatment on the graphitization of PAN-based carbon fibers is investigated as a function of Ni-P catalyst.The PAN-based carbon fibers are anodized in H3PO4 electrolyte resulting in the formation of active sites,which thereby facilitates the following electroless Ni-P coating.Carbon fibers in the presence and absence of Ni-P coatings are heat treated and the structural changes are characterized by X-ray diffraction and Raman spectroscopy,both of which indicate that the graphitization of PAN-based carbon fibers are accelerated by both the anodization treatment and the catalysts Ni-P.Using the anodized carbon fibers,the routine two-step pretreatment,sensitization and activation,is not needed.     

浅谈陶瓷山水画的构图与创作

<正>中国山水画迄今大约有一千五百多年的历史。其独特的民族风格与艺术魅力,对东方绘画艺术产生了重要影响。山水画的产生,是我们的先辈在创造文明的过程中,发现自然美,并给予艺术表现的结果,将自己对自然感悟后得到的意