N+离子注入聚(2-甲氧基-5-辛氧基)对苯乙炔薄膜的微观结构

通过双醚化反应、氯甲基化反应以及在强碱性条件下进行的脱氯化氢反应,制备出新型光电功能材料聚(2-甲氧基-5-辛氧基)对苯乙炔(PMOCOPV).采用能量为30 keV,剂量为1.2×1016 ions/cm2～4.8×1017 ions/cm2的氮离子(N )对PMOCOPV进行离子注入改性.红外光谱研究表明,离子注入改性后的PMOCOPV,在3433 cm-1和1622 cm-1处出现N-H的振动吸收峰;随着N 注入剂量的增加,PMOCOPV在紫外和可见光区域的吸收增强,且吸收边向长波方向移动;离子注入使PMOCOPV的分子链排列更加规整,取向度明显增加,结晶性能大大改善;离子注入后PMOCOPV的起始分解温度由未注入时的200 ℃提高至360 ℃,材料的热稳定性能显著增强.     

离子注入改性聚[2-甲氧基-5-(3''''-甲基)丁氧基]对苯乙炔微观结构与性能

采用低能氮正离子(N )对π共轭高分子聚[2-甲氧基-5-(3'-甲基)丁氧基]对苯乙炔(MMB-PPV)薄膜进行离子注入改性,注入剂量为9.6×1016 ions/cm2,能量为30 keV.利用红外光谱、紫外-可见吸收光谱、X射线衍射、透射电镜及热失重等手段对离子注入改性MMB-PPV薄膜的微观结构及热学性能进行研究.红外光谱显示,注入后分子侧链烷氧取代基的C-H振动峰强度减弱,同时在3442、1622 cm-1等处出现了N-H键的振动峰;薄膜的紫外-可见吸收光谱向长波方向移动,且在可见光区范围内的吸收强度增加;离子注入使聚合物分子链排列更加规整,取向度明显增大,结晶性能大大改善;经过离子注入后,聚合物材料的初始分解温度由未注入时的245.64 ℃提高至280.52 ℃,分子的热稳定性能显著增强.     

离子注入改性聚对苯乙炔的光学及电学性能

利用脱氯化氢反应制备π共轭高分子聚[2-甲氧基-5-(3′-甲基)丁氧基]对苯乙炔(MM B-PPV)。采用能量为15 keV~35 keV,剂量为3.8×1015ions/cm2~9.6×1016ions/cm2的低能氮离子(N+)对MM B-PPV薄膜进行离子注入改性研究。红外光谱显示,离子注入后分子的特征峰未发生显著变化,而在3442cm-1、1622 cm-1等处出现N-H键的振动峰;随着注入能量、剂量的增加,薄膜的紫外-可见吸收边向长波方向移动,π共轭高分子中激发态和基态间的光学禁带宽度变窄;薄膜的表面电导率随着注入能量、剂量的增加迅速提高,当注入能量为35 keV,剂量为9.6×1016ions/cm2时,表面电导率高达3.2×1-0 2S/cm,比本征态提高7个数量级以上。     

DOPO基阻燃腈纶聚合物的制备与燃烧性能

文中合成了反应型有机磷酸酯功能阻燃剂9,10-二氢-9-氧杂-10-磷杂菲-10-氧甲基丙烯酸酯(DOPOAA),并通过水相沉淀聚合制备了原位共聚改性的阻燃聚丙烯腈,利用红外光谱分析了阻燃聚丙烯腈链段组成,并通过与二乙基膦酸甲基丙烯酸酯(DEAMP)进行对比,详细研究了改性聚丙烯腈的热稳定性和燃烧行为。结果表明,芳环结构有机磷酸酯DOPOAA与单体丙烯腈的竞聚率较为接近;原位共聚改性的聚丙烯腈热稳定性与阻燃性能显著提升;较脂肪结构磷酸酯阻燃剂DEAMP,DOPOAA在气相中也起到了关键的阻燃作用,且在较低的磷含量时即可表现出优异的阻燃性能。当DOPOAA质量分数为15%时,改性聚丙烯腈第1阶段失重温度提高约30℃,热分解残炭量提高约30%,极限氧指数值可达25.1%,热释放速率峰值(pkHRR)降低至598.16 kW/m~2,总释放热(THR)下降为28.91 MJ/m~2,燃烧后的炭层表面致密、平滑,结构完整,阻燃性能优异。     

马来酸酐改性聚乙烯对玉米淀粉的修饰作用

通过干法工艺用马来酸酐改性聚乙烯(Zemac)修饰玉米淀粉,改变加碱量、Zemac用量及反应温度,探讨不同反应条件下产物的理化性质。结果表明,不同反应条件得到Zemac-starch取代度在0.0050~0.0113之间;红外光谱在波数为1700cm-1~1730 cm-1附近未检测到明显的羰基特征吸收峰,在波数为2850 cm-1~2900 cm-1附近的CH2对称振动峰有所增强;核磁共振氢谱中在δ0.7~3.0之间出现新的吸收峰,说明淀粉发生酯化反应。不同加碱量和Zemac加量对产物黏度有明显影响;随着反应温度升高,产物黏度有所上升,适当高温条件利于反应进行;偏光显微研究表明,随着Zemac-starch取代度的提高,淀粉颗粒的中心双折射性有所减弱,但产物结晶结构无明显变化。     

经钨离子束处理的H13钢的表面结构和成分研究

采用由金属蒸汽真空弧离子源(MEVVA)引出的强束流脉冲钨离子对H13钢进行了离子注入表面改性研究.注入剂量为3×1017cm-2,引出电压为48kV,平均束流为15μA*cm-2.利用卢瑟福背散射谱(RBS)测量了注入表面的成分,借助X射线衍射仪(XRD)和X射线光电子能谱仪(XPS)考察了注入表面的氧化情况及微观结构.研究发现,钨离子注入H13钢能减轻其表面铁元素的氧化;钨元素在其表面的原子百分比可达28%左右,并根据能带论确定了注入样品中钨和铁元素的电子结构.     

低能离子注入对PAn/Si异质结太阳电池的改性研究

利用电化学方法制备了聚苯胺 /Si太阳电池 ,将离子注入改性技术引用到聚苯胺 /Si异质结太阳电池的改性研究中 ,对离子注入后太阳电池顶区材料的吸收光谱和热稳定性能进行了研究 ,测量了改性后电池的输出特性。研究结果表明 :经离子注入改性后的聚苯胺吸收光谱明显变宽 ,材料的热分解温度较注入前提高了 40℃ ,电池在 10 92W/m2 光照时的转换效率提高了 18倍 ,在 37 2W/m2 光照时的转换效率提高了近 3倍     

低能离子注入对聚苯胺薄膜的改性研究

利用低能量的N 对电化学合成的聚苯胺薄膜进行了离子注入改性 ,实验结果表明 :聚苯胺薄膜经N 注入后薄膜电导率随注入能量和剂量的增加而提高 ,电导率最大提高了 9个数量级 ,即由本征态的电导率 (>1× 1 0 -12 S/cm)提高到 1 76× 1 0 -3 S/cm(注入剂量 :3× 1 0 17ions/cm2 ,注入能量 :35keV) ;同时离子注入后聚苯胺薄膜在可见光范围的吸收比增强。     

二异氰酸酯扩链聚2,5-呋喃二甲酸乙二酯

以2,4-甲苯二异氰酸酯(TDI)为扩链剂,对生物基聚2,5-呋喃二甲酸乙二酯(PEF)进行扩链,探讨了扩链剂用量(NCO/OH摩尔比)、反应时间、反应温度等因素的影响。采用红外光谱、核磁共振氢谱、元素分析、差示扫描量热法、X射线衍射分析了扩链PEF的分子结构、热性能和结晶性能。结果表明,当扩链剂用量n(NCO)/n(OH)=1~3,反应时间为30min,反应温度为230℃时扩链效果较好;扩链后PEF的特性黏度最高达1.24dL/g,重均相对分子质量(Mw)最高达28.8×104;扩链后PEF的结晶能力降低,热稳定性能相对提高。     

重氮片光敏性与热稳定性的研究

本文研究了九种不同结构重氮盐组成的重氮片的光敏性、热稳定性以及两者之间的相互关系,研究了各种添加剂对重氮片光敏性和热稳定性的影响。试验以堂氮片光解和热解时吸收值降低的百分率(A%)来测试重氮片的光敏性和热稳定性。测试结果表明:组成重氮片的重氮盐结构不同与其光敏性与热稳定性有直接关系,而添加剂加入重氮片不会影响其光敏性,但对由同一结构重氮盐所组成的重氮片的光敏性有一定的影响。重氮盐芳环中在重氮基间位上引入烷氧基后,可以提高由该盐所组成的重氮片的光敏性,如在邻位上引入烷氧基后,可以提高相应重氮片的热稳定性。重氮片热稳定性的好坏与构成该重氮片的重氮盐的热分解温度的高低有着密切的关系。     

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.     

Effect of Permeable Crystalline Material on Steel Reinforcement Corrosion of Concrete

Permeable crystalline materialcan permeate into pores and cracks of concrete and catalyze the reaction between Ca(OH) 2and unhydrated cement to generate a great quantity needle non-soluble crystals, which can stop up the pores and cracks of concrete, and increase the impermeability of concrete. This paper reported the results of a study conducted to evaluate steel reinforcement corrosion of concrete specimens uncoated and coated with permeable crystalline material as well as mixed with the permeable crystalline material. The properties evaluated for corrosion test were water impermeability, water absorption, compressive strength and potential. The results of water impermeability, water absorption, compressive strength clearly showed that the permeable crystalline material could prohibit water, any soluble salts and moisture from penetrating the concrete to cause corrosion, leaking, and other problems, and it did increase the compressive strength, which was favorable for protection of corrosion of reinforcing steel. Moreover, it was concluded from the potential-time curve that the steel reinforcement of uncoated specimen was in the state of activation whereas that of other specimens coated and mixed with the permeable crystalline material was in the state of inactivation. Above all, it was indicated that the permeable crystalline materialis very effective to protect the steel reinforcement of concrete from corrosion.     

The Research and Application About "Dry Peeling Off" Technology for Airplane Surface Paint Layer

In this paper, the principle of spurting take off lacquer were introduced; and with orthogonal method the unsaturate polyester was prepared ;it was easy to peel airplane paint layer off with this material and equipment.     

Quality Study of Honeycomb Core Shaping Without Wax Stabilization

Sandwich panels utilizing honeycomb cores result in lightweight, high-strength units that are very rigid. Indeed, they give honeycomb panels the best strength-to-weight ratio of any construction type available. Conventionally, the wax is poured into the cell of the core to strengthen the structure and prevent the core from being crushed during milling. Much time and labor is required to wax, mill, and clean the cores. In this study, the process of pouring wax into the core was skipped. In other words, the cutter directly milled the core. Experiments showed that the compressive strength of the core produced without wax stabilization was only 3% lower than that of cores produced using the traditional method. In addition, the drum peel strengths of cores produced without wax stabilization were 38.4% higher than cores produced using the traditional method, in which residual wax seriously polluted the adhesive. It was also found that eliminating the wax process can reduce costs.     

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.     

In-process thermal treatment of polylactic acid in fused deposition modelling

Polylactic acid (PLA) is one of the most widely used open source fused filament fabrication materials due to its ease of extrusion, biodegradability, and mechanical strength. The mechanical strength of PLA largely depends on the proper growth of its semi-crystalline structure, which can be severely impaired by a low rate of crystallization, particularly in open source printers. This can be further aggravated by the non-uniform thermal distribution of heat that causes improper curing among the extruded beads of the printing material. As a result, PLA printed on open source printers does not achieve the best mechanical properties. This research, for the first time, proposes an additive-free solution implemented through a detailed set of experimentation to improve the curing rate through in-process temperature variations to cure the joints among the beads. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy is used to confirm the improvements in the bead joints. This work is conducted in two phases of experiments. In the first phase, a full factorial ANOVA is used to investigate various process parameters and the important variables are used in the second phase to print test specimens in four different sets.     

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.