正交法探讨均相碱催化制备生物柴油的优化条件

以菜籽油为原料,甲醇钠为催化剂,二异丙醚为共溶剂,通过酯交换法制取生物柴油,并考察了醇油摩尔比、催化剂用量、共溶剂用量、反应时间和温度对生物柴油产率的影响.通过正交试验得出菜籽油与甲醇酯交换反应的最优条件为:醇油比为6:1,甲醇钠催化剂用量为油重的1.2%,共溶剂与油的摩尔比为1.2 :1,反应温度60℃,反应时间80min,低速120r/min搅拌强度下,转化率达到96.45%.制得的生物柴油各理化指标均符合美国和德国生物柴油测试标准.     

Hummers法合成石墨烯的关键工艺及反应机理

采用经典的Hummers法合成石墨烯,对合成温度、反应时间、氧化剂的添加量、还原剂的加入量等实验条件进行改变,研究了影响合成的关键工艺。结果表明:控制高温反应的温度在90～100℃范围内是提高产率最为关键的因素。控制低温反应的温度接近0℃,中温反应的温度为30～45℃,保证反应时间分别大于30min和60min,并添加过量的氧化剂,可以使产率得到一定的提高。     

Lewis酸性离子液体催化文冠果种仁油制备生物柴油

以盐酸三乙胺和不同金属氯化物FeCl3,CuCl2,SnCl2,ZnCl2为原料,合成了一系列Lewis酸性离子液体[Et3NH]Cl/MClX,将其用于催化文冠果种仁油和甲醇酯交换制备生物柴油。考察了离子液体的种类,反应温度,醇油摩尔比,催化剂用量和反应时间对生物柴油产率的影响。结果表明:在反应温度为70℃,醇油摩尔比为12,催化剂用量为原料油质量的5%,反应时间7h时,离子液体[Et3NH]Cl-2FeCl3催化酯交换制备生物柴油的产率可达95.4%。[Et3NH]Cl-2FeCl3具有较好的循环使用能力,循环使用6次后,催化性能没有明显降低。制备的生物柴油各项指标符合生物柴油国家标准GB/T20828-2007。     

地沟油在醇基燃料中资源化利用关键技术研究

以地沟油和甲醇为原料,以氢氧化钾为催化剂,研究了地沟油生产生物柴油的工艺,以酯化率为考察指标,探讨了醇油摩尔比、反应时间、反应温度和催化剂用量对酯交换反应酯化率的影响,确定了地沟油生产生物柴油的最适宜条件为反应温度65℃,反应时间2.5h,醇油质量比为1∶5,催化剂用量为9%(占油质量比),其转化率可达到92.1%,该最佳制备条件稳定性和重现性良好,且以此最佳条件制备的生物柴油流动性能和燃烧性能较好;同时从正己醇、油酸、仲辛醇和环已醇中筛选出1∶1∶1正己醇-油酸-仲辛醇为助溶剂,以此为助溶剂的生物柴油--醇基燃料溶液均一稳定,互溶效果良好。还研究了促燃剂二茂铁对生物柴油-醇基混合燃料燃烧热的影响,结果表明当二茂铁为0.60%时,助燃效果好,而且减少了消烟和炭残渣遗留量。最终获得了生物柴油-醇基燃料最佳配方为生物柴油12%,助溶剂8%,助燃剂0.60%。以此配方生产的生物柴油-醇基混合燃料污染小,热值高,且经济效益良好。     

超声辐照合成Salen金属配合物的初步研究

将超声应用于Salen配体与金属配合的过程中,在超声辐照条件下分别合成了手性及非手性的Salen金属配合物:N,N'-双水杨醛缩乙二胺钴、N,N'-双水杨醛缩乙二胺锰和(S,S)-N,N'-双(水杨醛)-1,2二苯基乙二胺钴,通过元素分析、红外光谱、核磁进行了表征。讨论了反应时间、温度、以及超声波声强对产率的影响,并与常规的合成方法进行了比较。研究结果表明:在合成过程中采用变幅杆式超声波发生器,以乙醇做溶剂,Schiff base与醋酸盐在60℃下超声波声强为1.35W.cm-2左右时反应较短时间内即可完成,其配位时间大大减少,其中配体和醋酸锰的配位时间由原来的12h缩短到2.5h,反应温度的也由80℃降低到60℃,并且获得95%的产率。     

超声波辅助潲水油直接酯交换法制备生物柴油

采用潲水油和甲醇为原料,KOH作为催化剂,通过酯交换反应制备生物柴油。综合考察了反应时间、反应温度、催化剂用量、醇油摩尔比和超声波功率5个因素对酯交换反应制备生物柴油的影响。并且采用L9(34)正交试验法对实验结果进行分析和优化,最终确定反应的最佳条件如下:醇油摩尔比为8∶1、催化剂用量为油重的1.2%、反应时间为50min、反应温度为70℃,超声波功率为400W,转化率最高可达97.53%。     

精制棕榈油制备生物柴油的实验研究

以精制棕榈油为原料，与无水乙醇进行酯交换反应制取生物柴油。探讨了反应物配比、催化剂用量、温度、反应时间等因素对产物产率的影响，采用正交实验优化合成条件确定了最佳合成条件及影响反应的关键因素，并运用气相色谱一质谱技术分析了产物的结构和组成，运用核磁共振技术对主要成分进行了结构确定。结果表明该生物柴油符合《柴油机燃料调和用...     

精制棕榈油制备生物柴油的实验研究

以精制棕榈油为原料,与无水乙醇进行酯交换反应制取生物柴油。探讨了反应物配比、催化剂用量、温度、反应时间等因素对产物产率的影响,采用正交实验优化合成条件确定了最佳合成条件及影响反应的关键因素,并运用气相色谱-质谱技术分析了产物的结构和组成,运用核磁共振技术对主要成分进行了结构确定。结果表明该生物柴油符合《柴油机燃料调和用生物柴油国家标准》(GB/T20828-2007),接近美国和德国的生物柴油标准,基本符合《轻柴油》(GB252-2000),适于中小规模及大规模生产应用。     

超声波强化连续制备小桐子生物柴油的动力学研究

在优化的物料醇油的物质的量比为6∶1、催化剂KOH用量为小桐子油质量的1.2%和超声波功率为180W条件下,研究超声波强化连续制备小桐子生物柴油的动力学行为,采用Origin软件拟合曲线方程,建立宏观动力学模型。结果表明,超声波强化连续酯交换反应制备小桐子油生物柴油的反应基本遵循1.87级,反应速率随温度的升高而加快,二者符合Arrhenius方程,该反应的活化能为36.66kJ·mol-1,频率因子为8.98×106。建立的反应动力学模型将为扩大试验和在超声波作用下管道式连续酯交换制备小桐子油生物柴油工艺的工业化应用提供理论依据。     

氨基酸离子液体清洁催化合成阿司匹林

以氨基酸为原料采用一步法合成了3种氨基酸离子液体,将其代替浓H2SO4用于催化乙酸酐和水杨酸的乙酰化反应,清洁合成阿司匹林。考察了离子液体种类及用量、原料配比、反应温度、时间等因素对合成阿司匹林的影响。结果表明,该离子液体对于合成阿司匹林具有良好的催化效果,在水杨酸20mmol、乙酸酐40mmol、谷氨酸硫酸盐离子液体([Glu]HSO4)2mmol、反应温度70℃、反应时间30min的条件下,阿司匹林分离产率可达84.8%。增大投料量,产率还会进一步升高,并且离子液体可重复使用。     

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.