Ordered mesoporous Pd/SnO2 synthesized by a nanocasting route for high hydrogen sensing performance

Ordered mesoporous SnO₂ and mesoporous Pd/SnO₂ have been successfully synthesized via nanocasting method using the hexagonal mesoporous SBA-15 as template. Two different procedures, impregnation technique and direct synthesis, were utilized for the doping of Pd in the mesoporous SnO₂. The results of small angle X-ray diffraction (SAXD), nitrogen adsorption–desorption and transmission electron microscopy (TEM) demonstrate that the SnO₂ and Pd/SnO₂ display ordered mesoporous structures and high surface areas. Wide angle X-ray diffraction (WAXD) and X-ray photoelectron spectroscopy (XPS) reveal tetragonal structure of SnO₂ and the existence of Pd element. The sensing properties of mesoporous SnO₂ and mesoporous Pd/SnO₂ for H₂ were detected. The sensor utilizing mesoporous Pd/SnO₂ via direct synthesis method exhibits excellent response and recovery behavior and much higher sensitivity to H₂, compared to those using mesoporous SnO₂ and mesoporous Pd/SnO₂ via impregnation technique. It is believed that its high gas sensing performance is derived from the large surface area, high activity and well dispersion of Pd additive, as well as high porosity, which lead to highly effective surface interaction between the target gas molecules and the surface active sites.     

超微粉碎技术在中药和保健食品中的应用

超微粉碎技术是近20年来发展起来的一项新技术,由于其具有独特的物理和化学性质,因此被广泛应用.中药材和保健食品中的有效成分主要分布于细胞内,采用超微粉碎技术可以极大增加其溶出和促进人体吸收利用.本文主要介绍了近年来国内超微粉碎技术在中药和保健食品上的研究与应用情况,并为超微粉碎技术发展前景做出展望.     

香蕉低聚糖的分离纯化及理化性质研究

以香蕉为原料,采用水浸提得到粗糖液,通过SephadexG-25柱层析纯化得到香蕉低聚糖,并初步分析所得低聚糖的理化性质。结果表明:水浸提香蕉低聚糖的优化工艺条件是:料液比为(g:mL)1∶2,温度为60℃,提取时间为60min,提取2次;凝胶柱层析操作条件为:进样体积1.0mL,洗脱液流速为10s/滴,收集体积2.0mL,得到2种低聚糖;香蕉低聚糖-1为浅黄色粉末,无臭,水溶性不好,吸湿性不强;香蕉低聚糖-2为黄色粉末,无臭,水溶性良好,有一定的吸湿性;凝胶渗透色谱法测出香蕉低聚糖-2的数均分子质量为1313。     

聚类分析法监控不同存放期复配烟用香精的质量稳定性

通过调整色谱检测数据中各组分峰面积权重系数的方式,建立以复配烟用香精样品感官评价结果为依据的聚类分析图,实现以色谱检测数据监控复配烟用香精样品存放期间质量稳定性的目标.建立的复配烟用香精保存时间回归矩阵模型,可对不同存放期(0～10月)复配烟用香精的质量情况进行评估.     

K5浆料在涤/棉包芯纱中部分取代PVA的上浆性能探讨

在常用涤/棉包芯纱浆料配方的基础上,用新型的变性淀粉K5取代50%的PVA,测试了浆液和浆纱的性能,并对浆纱效果进行了分析。结果表明:加入K5浆料的配方浆纱性能优异,浆液黏度热稳定性好。特别是对涤/棉包芯纱的上浆,能较好地改善浆纱质量。     

液体深层发酵法制备灵芝苹果保健醋的工艺研究

研究了以苹果、灵芝为主要原料，采用液体深层发酵技术，经酒精发酵，醋酸发酵制备灵芝苹果保健醋的工艺条件，并探讨了酵母菌种，醋酸菌种的驯化培养和醋酸发酵条件的优化。     

一种面向单片机的高级语言的实现

主要介绍了开发了一种面向单片机的高级语言ＥＳＤＬ。首先介绍了ＥＳＤＬ语言具有的特点,然后介绍了该语言的编译器实现过程中模块组织形式及内部信息表示方式。     

IN-SITU OBSER VATION OF SINGLE-POINT WEAR OF PM Al-Ti ALLOY

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