稀土锰氧化物La0.7Ca0.3Mn1-xCuxO3低场磁电阻及电传输特性研究

采用溶胶-凝胶法制备了系列多晶CMR材料La0.7Ca0.3Mn1-xCuxO3（x=0%,1%,5%,10%,15%,20%）。在77-350 K温度范围内测量了样品的电阻率及磁电阻大小。实验结果发现：系列样品TC随掺杂量增加而递减;系列样品的电阻率峰及磁电阻峰在整个测温范围内随掺杂量的增加均依次被展宽直至消失,当掺杂量为x≥10%时,电阻率随温度的变化在整个测温范围内呈现绝缘相行为;同时还发现,掺杂量为x≥10%时,样品的磁电阻在整个测温区内基本表现为隧穿磁电阻。基于我们采用蒙特卡罗模拟方法提出的逾渗模型及隧穿磁电阻模型,对样品的磁电阻行为进行了很好的解释。对系列样品的ρ-T曲线进行lnρ-T^-（1/4）系拟合,发现掺杂量为x=10%样品在整个温区内的lnρ-T^-（1/4）系基本呈线性。     

Development of new solid-phase microextraction fibers by sol-gel technology for the determination of organophosphorus pesticide multiresidues in food

Allyloxy bisbenzo 16-crown-5 trimethoxysilane was first used as precursor to prepare the sol-gel-derived bisbenzo crown ether/hydroxyl-terminated silicone oil (OH-TSO) SPME coating. The coating procedure involving sol solution composition and conditioning process was presented. Compared with commercial SPME stationary phases, the new coatings showed higher extraction efficiency and therefore could provide higher sensitivity for organphosphorous pesticides (OPs). Limits of detection (LODs) were in the range of 0.003-1.0 ng/g for these OPs in food samples (honey, juice, orange and pakchoi). The optimal extraction conditions of the new coatings to OPs in these samples were investigated by adjusting extraction time, salt addition, extraction temperature, and dilution ratios of samples with distilled water by using SPME coupled with gas chromatography (GC)-flame photometric detection (FPD). The method was applied to determine the concentrations of OPs in real samples.     

仪器分析测试技术信息化教学探索与实践

针对高职学生的特点，以仪器分析测试技术课程实训教学为例，按照课前布置学习任务，学生翻转课堂学习，"教、学、做"一体化课堂教学，课后复习巩固的形式，开展信息化教学的探索与实践，并对信息化教学的效果和存在的问题进行了分析。通过信息化教学改革，仪器分析测试技术课程突破了传统教学时空的限制，激发了学生学习的兴趣，构建了"学生主体、教师主导"的教学新模式，提高了课堂教学效果，对推动高职课堂信息化教学的改革具有一定的借鉴意义。     

基于微机械加工技术的双腔型生物传感器

利用微机械加工技术研制了具有三维结构的腔型传感器，双腔型工作电极与Ag/Agcl参比电极集成在同一微芯片上。考察了微腔型电极的电化学特性及其对H2O2含量的测定。并以此为基础电极制备了半乳糖、葡萄糖双腔型生物传感器。结果表明，该传感器可同时测定半乳糖、葡萄糖双组分，线性上限分别为4．5mmol/L和4．0mmol/L。而且在测试双组分过程中，没有观察到明显的交叉干扰现象。     

一种基于流动注射梯度技术识别异常峰及校正的方法

基于流动注射梯度信息提出了一种利用梯度比均值进行定量的校正方法。方法具有在线自动判别和修复异常峰并自行校正的功能，和通用的标准系列定量方法相比，两者测定精度相当。但本文提出的方法抗干扰能力明显优于后者，可适用于在线过程监测。     

Miniaturization of separation techniques using planar chip technology

Miniaturization of separation columns implies equally reduced vol- umes of injectors, detectors, and the connecting channels. Planar chip technology provides a powerful means for the fabrication of micron-sized structures such as channels. This is demonstrated by two examples. An optical absorbance detector chip exhibits the expected behavior of a 1 mm optical path length cell despite its volume of 1 nL. A capillary electrophoresis device allows integrated injections of 100 pL samples, efficiencies of 70,000 to 160,000 theoretical plates in 10 to 20 seconds, and external laser-induced fluorescence detection at any capillary length of choice between 5 and 50 mm.     

生物质裂解产物的制备及HPLC检测其成分的虚拟仿真实验开发

In order to improve university laboratory teaching and practical education under the background of information technology, as well as overcome the difficulty for practical training, develop a virtual simulation experiment platform for rapid pyrolysis of natal materials and high-performance liquid chromatographic (HPLC) detection of its components. The experiment integrates the actual operation process of the plant to produce cleaved products by rapid pyrolysis of biomass with HPLC detection. The virtual experiment is divided into biomass sample pretreatment, rapid biomass pyrolysis, bio-oil extraction, and HPLC determination of complex components, making the biomass cleavage workshop "real" through simulation. This virtual simulation experiment fully integrates the utilization of biomass resources and basic chemistry courses (such as organic chemistry, instrumental analysis, chemical engineering principles, etc.), which are widely involved in agricultural and forestry majors with advantageous characteristics value.     

CaO和NaCl焙烧混合稀土精矿过程中的分解反应

用XRD和TG-DTA热分析技术, 研究了含独居石和氟碳铈镧矿的混合稀土精矿在100～1000 ℃焙烧过程中, 添加CaO, NaCl时, REPO4和REFCO3的分解反应. 研究结果表明: 不添加CaO和NaCl时, 仅在377～450 ℃范围内存在REFCO3的分解反应, 其产物是REOF, RE2O3, 以及Ce2O3进一步的氧化产物CeO2, 而REPO4不分解; 添加CaO后在660～750 ℃之间, CaO有3种分解作用: (1) CaO分解REPO4, 其产物是RE2O3和Ca3(PO4)2. (2) CaO分解REOF, 其产物是RE2O3和CaF2. (3) CaO和REOF的分解产物CaF2共同作用分解REPO4, 其分解产物为RE2O3, Ca5F(PO4)3; 添加CaO, NaCl后, 混合精矿的分解率明显提高, NaCl的作用是为反应体系提供了液相, 促进了固相反应物间的传质过程, 加快了反应速度. 与此同时NaCl还可能参加了CaO分解REPO4的反应.     

Topographical properties of polymer films deposited in capillaries for electrophoretic separations of large organic molecules

Topography and thickness of hydrophilic polymer coatings of fused-silica capillaries for capillary electrophoresis (CE) were investigated using atomic force microscopy (AFM), scanning electron microscopy (SEM), and profilometry. Three hydrogels, poly(2-hydroxyethyl methacrylate) [poly(HEMA)], poly(diethylene glycol monomethacrylate) [poly(DEGMA)], and poly(triethylene glycol monomethacrylate) [poly(TEGMA)], were deposited using two procedures, either by simple physical sorption of the polymers, or by derivatization of the capillary wall surface with glycidyl methacrylate (EPMA) followed by polymerization of the appropriate monomers. The performance of the modified capillaries was tested under CE conditions (decrease in the electroosmotic flow, EOF dependence on pH, separation of milk and standard proteins). It has been found that the most important property of the polymer coating is its thickness, whereas its topography and the degree of its hydrophobicity are less significant. Film deposition by physical adsorption is preferable to polymerization on the derivatized surface.