Fe3O4/壳聚糖磁性微球功能化SBA-15介孔分子筛的合成

通过反相悬液交联法制备出了Fe3O4壳聚糖磁性微球,以3-丙胺基三乙氧基硅烷(APTES)为硅烷偶联剂,采用后修饰法得到硅烷化SBA-15介孔分子筛.以戊二醛为交联剂将Fe3O4壳聚糖磁性微球接枝在硅烷化SBA-15介孔分子筛上.运用X射线衍射、傅里叶红外光谱等手段对Fe3O4壳聚糖磁性微球(MCS)接枝后的硅烷化SBA-15介孔分子筛进行了表征.分析结果表明,Fe3O4壳聚糖磁性微球通过硅烷偶联剂以化学键形式结合在SBA-15介孔分子筛上.     

SBA-15介孔硅片胺基修饰及其CO_2吸附

以3-氨基丙基三乙氧基硅烷(APTS)和N-[3-(二甲氧基甲硅烷基)丙基]乙二胺(TPED)为表面胺基修饰剂,通过化学接枝法制备了胺基修饰的SBA-15介孔硅片(SBA-15-EHP)吸附剂。采用SEM、全自动气体吸附仪、XRD、TGA等测试手段对胺基修饰的SBA-15-EHP进行表征,研究了胺基修饰的SBA-15-EHP的表面形貌,孔隙结构,晶体结构,SBA-15-EHP表面胺基的接枝量及CO_2的吸附特性。结果表明,在常压、35℃下,TPED修饰的SBA-15-EHP的CO_2吸附能力优于APTS修饰的SBA-15-EHP,最大的CO_2吸附容量为53.0mg/g,这是由于胺基与CO_2发生酸碱反应形成盐类的可逆化学吸附过程所致。     

Co_3O_4纳米粒子的表面接枝改性研究

以含乙烯基的硅烷偶联剂(A-151)处理Co3O4纳米粒子,在Co3O4粒子表面引入乙烯基,然后以K2S2O8为引发剂,十二烷基苯磺酸钠(SDBS)为乳化剂,采用乳液聚合,在Co3O4粒子表面接枝甲基丙烯酸丁酯,研究了影响Co3O4纳米粒子表面接枝的有关因素,并优化工艺参数。采用红外光谱、X射线光电子能谱等手段对表面接枝进行了表征。结果表明,甲基丙烯酸丁酯已经被成功地接枝到纳米Co3O4粒子的表面。热流传感器的热流灵敏度测试结果表明,Co3O4粒子表面改性后,它与硅树脂的复合涂层提高了热流传感器的热流灵敏度,相对于未处理的Co3O4粒子涂层,传感器灵敏度从0.052 mV.cm2/W提高到了0.065 mV.cm2/W。     

介孔分子筛/线性酚醛树脂杂化材料的制备及表征

利用水热法合成介孔分子筛(SBA-15),选择KH560对其表面进行修饰后采用原位聚合的方法制备了介孔分子筛/线性酚醛树脂(SBA-15/PF)有机无机杂化材料。通过傅立叶红外光谱(FT-IR)、X射线衍射(XRD)、N2吸附和热失重分析(TGA)等表征手段对杂化材料的制备过程进行跟踪研究。结果表明,KH-560已嫁接到SBA-15的内外表面,线性酚醛树脂分布于介孔分子筛孔道内外,并与SBA-15存在键接作用,形成有机无机互穿网络结构;表面修饰过程对SBA-15有序结构影响较小,而原位聚合会破坏介孔分子筛部分有序结构。     

十二烷基硫酸钠对溶液燃烧合成多孔Co3O4粉体形貌及磁学性能的影响

采用盐助溶液燃烧合成法制备多孔Co3O4粉体,并对十二烷基硫酸钠(SDS)为辅助盐合成的Co3O4粉体分别在500、600和700℃进行热处理,研究其微观形貌、结构和磁学性能.研究结果表明,燃料中引入SDS作为表面活性剂,起到发泡和细化晶粒的作用,热处理对Co3O4粉体的形貌、结构及磁学性能产生明显影响.在n(Co(NO3)2·6H2O):n(SDS)=1:0.075时合成的Co3O4粉体经700℃热处理后得到了高纯度、空间网状结构好、平均晶粒尺寸为100 nm的纳米晶Co3O4粉体.经500、600及700℃热处理后Co3O4粉体的矫顽力和剩磁逐渐增大,其中700℃热处理后粉体的矫顽力和剩磁最大,矫顽力为316.8 Oe,剩磁为31.5×10-3 emu/g.     

SnO2纳米晶修饰多孔Co3O4纳米棒的制备及气敏性能研究

以CoCl2.6H2O和CO(NH2)2为原料采用水热法合成多孔Co3O4纳米棒,之后通过自组装的方法将SnO2纳米晶修饰到多孔Co3O4纳米棒上。研究了SnO2纳米晶修饰对多孔Co3O4纳米棒气敏性能的影响。气敏测试结果表明SnO2纳米晶的修饰明显增强了多孔Co3O4纳米棒对CH3CH2OH和H2S的响应,对CH3CH2OH和H2S的检出下限分别达到5.0×10-6和1.0×10-6。     

四氧化三钴的制备及在过氧化氢电化学传感器中的应用

以六水氯化钴、聚乙烯亚胺和辛胺为主要原料,通过水热法得到片状氢氧化钴（Co(OH)2）前驱体,并进一步煅烧得到片状Co3O4电催化活性材料。采用滴涂法制备Co3O4/GCE修饰电极,通过循环伏安法和计时安培法对过氧化氢（H2O2）进行电化学检测分析,研究煅烧温度对所得到的Co3O4形貌以及H2O2检测性能的影响。结果表明：经200 ℃煅烧得到的Co3O4晶体为稳定的六方形片状结构,修饰电极200-Co3O4/GCE对H2O2检测表现出最高的响应电流值,该电极电流响应值与H2O2浓度在0.01~0.20 mmol/L范围内具有良好线性关系,检测限为6.53 μmol/L(S/N=3),灵敏度为875.66 μA/(mmol·L-1·cm2);同时修饰电极Co3O4/GCE在对H2O2检测中表现出较好抗干扰能力。     

负载磷钼杂多酸/La0.7Ca0.3Fe0.25Co0.75O3/聚吡咯的制备及光催化性能研究

采用甘氨酸-硝酸盐燃烧法成功制备了La0.7Ca0.3Fe0.25Co0.75O3钙钛矿型复合氧化物,以(NH4)2S2O8为氧化剂,运用化学氧化法合成La0.7Ca0.3Fe0.25Co0.75O3/聚吡咯薄膜,然后通过静电自组装方法制备了一种新的表面负载修饰型复合光催化剂La0.7Ca0.3Fe0.25Co0.75O3/PPy/PMO12。采用XRD、SEM、FT-IR对催化剂的物化结构进行了表征。光催化性能测试是以亚甲基蓝染料的水溶液为降解目标,结果表明,PMo12的负载修饰改进了La0.7Ca0.3-Fe0.25Co0.75O3/PPy光催化剂的催化活性。     

Co3O4/GO复合材料的制备及其对Pb2+和Cd2+的电化学检测

通过简单的水热-热分解法制备了Co3O4/GO复合材料,利用场发射扫描电子显微镜(FESEM)、X射线衍射(XRD)、傅里叶红外光谱(FT-IR)、拉曼光谱(Raman)对样品进行结构形貌表征.将制备的Co3O4/GO复合材料作为电极修饰材料构建电化学传感器对溶液中的Pb2+和Cd2+进行检测,测试采用差分脉冲阳极溶出...     

Co修饰CeO2复合材料的晶面调控及其光热催化脱硝性能

采用一步水热法，通过调节Co与Ce的摩尔比，制备出暴露高活性晶面的Co修饰CeO₂复合材料。利用比表面和孔径分析仪、TG-DSC、TEM、SEM、XRD、紫外-可见分光光度计(UV-vis)、XPS、光热催化脱硝技术对Co修饰CeO₂复合材料进行全面表征。结果表明，随着Co元素含量的增加，Co修饰CeO₂复合材料的比表面积增大，CeO₂呈纳米棒状结构，Co与表面氧生成Co₃O₄，二者的共结晶过程降低了复合材料的结晶表面能，使CeO₂主要暴露(200)和(220)高活性晶面，且暴露比例增大。光热催化脱硝结果表明，当Co与Ce摩尔比为15%、煅烧温度为400℃时，Co修饰CeO₂复合材料的光热催化效率达到最高，为98%。      

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.