诺氟沙星-Zn2+金属分子印迹膜色谱的制备及性能

将膜色谱技术和分子印迹技术相结合,制备了诺氟沙星-Zn2+金属分子印迹膜色谱。采用扫描电镜分别观察了聚合物和膜色谱的结构,并考察了不同印迹聚合物填充量对膜色谱的纯水通量和对目标分子的吸附识别能力的影响。结果表明,阶段性升温沉淀聚合制备的印迹聚合物微球粒径均一,适合做膜填充吸附剂。随着填充量的增加可以明显观察到膜内的填充物增加,膜色谱的结构变致密。当填充量为45%(质量分数,下同)、聚偏氟乙烯(PVDF)16%、聚乙二醇(PEG)-400 15%、聚乙烯吡咯烷酮(PVP)3%;铸膜液温度为50℃,凝固浴温度为20℃时制备得到的诺氟沙星-Zn2+金属分子印迹膜色谱的吸附容量为72 mg/g。     

L-苹果酸分子印迹聚合物微球的制备及性能评价

以L-苹果酸为模板分子,丙烯酰胺(AA)、乙二醇二甲基丙烯酸酯(EGDMA)分别为功能单体和交联剂,采用沉淀聚合法制备了分子印迹聚合物微球,研究了聚合体系组成对模板聚合物吸附特性的影响。实验表明,以1∶4∶20的物质的量比加入模板分子、AA和EGDMA时,制备的模板聚合物吸附容量高,印迹效果好。通过Scat-chard分析研究了聚合物的选择结合性能,结果表明分子印迹聚合物微球在识别L-苹果酸的过程中存在2类结合位点,而空白印迹聚合物微球只存在1类结合位点。印迹聚合物微球对L-苹果酸和D-苹果酸的手性分离因子α达2.05。     

萘普生分子印迹拆分过程热力学研究

采用4-乙烯基吡啶为功能单体,三甲氧基丙烷三甲基丙烯酸酯为交联剂,制备出(S)-萘普生的分子印迹聚合物,并将其用作高效液相色谱固定相,对其进行了评价.研究了流动相流速、不同功能单体和柱温对拆分效果的影响,测定出分离过程的热力学参数,证明萘普生分子印迹拆分过程是焓控过程.     

水相中色氨酸分子印迹聚合物微球的合成、表征及其识别性能研究

分别以色氨酸、α-甲基丙烯酸或丙烯酸胺、三羟甲基丙烷丙烯酸酯、甲苯作为模板分子、功能单体、交联剂和致孔剂,在较佳工艺条件下水体系中合成了色氨酸分子印迹聚合物微球;其形貌、粒径分布以及模板分子与功能单体之间的相互作用分别通过SEM、激光粒度分析仪及紫外分光光度法进行表征.其吸附能力分别通过静态吸附法测定其分离因子(α)和相对分离因子(β)来确定.实验结果表明,该法合成的色氨酸分子印迹聚合物对底物具有较高的吸附选择性和较大的吸附容量.     

活性自由基聚合的白藜芦醇分子印迹聚合物的合成及在葡萄皮白藜芦醇分析中的应用

RAFT试剂介入制备白藜芦醇分子印迹聚合物并用于实际样品中白藜芦醇的分离富集。以二苄基三硫代碳酸酯(DBTTC)为RAFT试剂,以白藜芦醇为印迹化合物,以丙烯酰胺作为功能单体,利用可逆加成-断裂链转移自由基聚合法(RAFT)制备了白藜芦醇分子印迹聚合物。利用扫描电镜、红外光谱和色谱法考察了单体与交联剂比例、引发剂用量、溶剂用量、反应时间和反应温度对印迹聚合物形态结构、印迹聚合物的识别能力及分离效率的影响。结果显示,利用RAFT聚合法制备的白藜芦醇分子印迹聚合物对模板分子的结合量Q达到1 283μg/g,并具有特异性识别作用。通过活性自由基聚合法合成的分子印迹聚合物具有更好的形态结构,对目标分子具有较高的吸附效率。     

分子印迹聚合物结合与识别能力的影响因素

分子印迹技术是近年来迅速发展起来的一种分子识别技术,被应用于色谱分离、固相萃取、药物分析、环境监测、仿生传感器、催化等领域.结合与识别能力是分子印迹聚合物的重要性能,详细分析了分子印迹聚合物结合与识别能力的影响因素.     

壳聚糖与牛血清白蛋白分子印迹聚合物的制备与表征

利用壳聚糖为功能单体,在模板分子牛血清白蛋白存在下,采用滴加成球法制备出对牛血清白蛋白(BSA)具有特异识别性能的分子印迹聚合物,并用原子力显微镜(AFM)及红外光谱进行了表征。实验结果表明,利用壳聚糖制备的牛血清白蛋白分子印迹聚合物对牛血清白蛋白具有特异识别功能,显示出明显的印迹效果。这种特异分子印迹介质的制备,为分离提纯特种结合蛋白提供了一种优良方法。     

水相中L-组氨酸单分散分子印迹聚合物微球的合成、表征及其识别性能研究

较佳工艺条件下,在水性体系中选用无皂乳液聚合法制得的单分散微米级聚苯乙烯微球为种球,分别以组氨酸、甲基丙烯酸(MAA)或丙烯酸胺(AM)、乙二醇二甲基丙烯酸酯(EDMA)为模板分子、功能单体和交联剂,合成了L-组氨酸分子印迹聚合物微球。研究了形貌、粒径及其分布以及模板分子与功能单体之间的相互作用,分别以SEM、激光粒度分析仪紫外分光光度法和红外光谱表征功能单体与交联剂之间的共聚情况,通过静态吸附法分别测定其分离因子(α)和相对分离因子(β)来评价其吸附性能。结果表明,该法合成的分子印迹聚合物微球对底物具有较高的吸附选择性和较大的吸附容量。     

2,4,6-三硝基甲苯磁性分子印迹聚合物的合成

以2,4,6-三硝基甲苯(TNT)为模板分子、氨丙基三乙氧基硅烷为功能单体、正硅酸乙酯为交联剂,采用溶胶凝胶法成功制备了对TNT具有特异选择识别功能的磁性分子印迹聚合物。合成制备的磁性分子印迹聚合物具有良好的磁响应性,在外加磁场下可实现快速分离。红外光谱(FT-IR)、X射线光电子能谱和扫描电镜结果证实聚合物为核壳结构,磁性粒子由硅烷偶联剂完全包覆,并在其表面形成了一层分子印记聚合物;静态吸附实验结果表明,制备的磁性分子印迹聚合物对模板分子TNT具有良好的吸附能力,其饱和吸附量为77mmol/kg;通过以3,4-二硝基甲苯(DNT),为结构相似物的吸附选择性实验,磁性印迹聚合物对模板分子表现出良好的特异选择性。     

镉(Ⅱ)-乙二醛缩双邻氨基酚印迹聚合物的制备及其吸附性能

以Cd-乙二醛缩双邻氨基酚的配合物为模板分子,α-甲基丙烯酸(MAA)作为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,制备了镉-乙二醛缩双邻氨基酚的分子印迹聚合物。研究了该印迹聚合物对模板分子的吸附和选择性识别,并用火焰原子吸收法考察了溶液的浓度、温度和吸附时间等因素对聚合物吸附性能的影响。结果表明,印迹聚合物对模板分子具有较好的吸附性和选择性,吸附45 min达到平衡。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.