淀粉-聚(苯基缩水甘油醚)接枝共聚物的合成反应研究

研究了以萘钠为引发剂，在淀粉乙酸酯上进行苯基缩水甘油醚（PGE），γ－丁内酯（γ－BL）开环接枝聚合的反应，首先将淀粉进行部分乙酰比，制备取代度为1．5的淀粉乙酸酯，之后以萘钠将淀粉乙酸酯的羟基转化为醇氧盐，再引发PGE，γ－BL进行负离子开环接枝聚合，采用凝胶渗透色谱（GPC）对接枝前后聚合物分子量的变化进行研究，并通过接枝率，1H－NMR波谱对淀粉－聚（苯基缩水甘油醚）接枝共聚物（St-g-PPGE)进行了表征，结果表明，以萘钠为引发剂，PEG能够在淀粉乙酸酯上进行均相接枝聚合，接枝率在70％－150％之间，接枝后聚合物的分子量明显增大。     

甲基丙烯酸酰基氧乙酯新型单体的合成及其均聚支化研究

首次合成了甲基丙烯酸乙酰（丙酰、正丁酰及异丁酰）氧乙酯新型单体，对其结构进行了鉴定。通过粘度法和小角激光散射法，确立了诸单体均聚物的Ｍａｒｋ－Ｈｏｕｗｉｎｋ方程，并详细讨论了均聚物产生支化的机理。     

P(MMA-BA-MAA)／P(MMA-BA-VP)共聚物复合体系的氢键相互作用

通过乳液共聚合分别合成了两种具有互补结构的共聚物乳液：聚（甲基丙烯酸甲酯－丙烯酸丁酯－甲基丙烯酸聚Ｐ（ＭＭＡ－ＢＡ－ＭＭＡ）和聚（甲基丙烯酸甲酯－丙烯酸丁酯－乙烯基吡咯烷酮）Ｐ（ＭＭＡ－ＢＡ－ＶＰ）。通过^1H-NMR测定,研究了共聚物组成与单体投料组成的关系;通过ＦＲ－ＩＲ、ＤＳＣ、表 及力学性能测试,研究了Ｐ（ＭＭＡ－ＢＡ－ＭＭＡ）／Ｐ（ＭＭＡ－ＢＡ－ＶＰ）共聚物复合体系氢键相互作用及其对聚合物性能的影响,结果表明Ｐ（ＭＭＡ－ＢＡ－ＭＭＡ）／Ｐ（ＭＭＡ－ＢＡ－ＶＰ）共聚物复合体系存在氢键相互作用,氢键相互作用导致复合体系表面降低、拉伸强度提高。     

水溶性三重响应智能聚合物的合成与性能

在CuCl/Me6TREN催化体系下,以含2-溴异丁酰基团的偶氮苯衍生物引发甲基丙烯酸-N,N-二甲氨基乙酯（DMAEMA）的原子转移自由基聚合（ATRP）,得到新型水溶性三重响应智能聚合物。该聚合物可同时对光、热和pH等外部环境刺激产生响应性。利用凝胶色谱（GPC）表征聚合物的分子量及其分布。该聚合物常温下溶于水,其...     

甲基丙烯酸三氟乙酰氧乙酯的聚合

对甲基丙烯酸三氟乙酰氧乙酯(TFAOEMA)的阴离子聚合及原予转移自由基聚合进行了研究。常用的阴离于引发剂如丁基锂、1，1-二苯基已基锂等很难引发TFAOEMA的阴离子聚合，而碱性较弱的引发剂如三乙基铝却容易引发，且产率较高。以氯化亚铜、五甲基二乙基三胺、溴代丙酸乙酯为引发体系的TFAOEMA的本体原子转移自由基聚合符合活性聚合特征。但在四氢呋喃为溶剂的原子转移自由基聚合中却存在活性中心失活现象。以末端含卤素的聚甲基丙烯酸甲酯为大分子引发剂，引发TFAOEMA的原子转移自由基聚合，得到了含氟双嵌段聚合物。     

具有“树枝状”结构的短氟碳链含氟单体的合成与表征EI北大核心CSCD

首先以乙二醇单乙烯基醚为成核分子引发缩水甘油开环聚合,优化反应条件,合成中心含乙烯氧基的超支化聚缩水甘油醚;后将其磺酸酯化,在40℃,氟醇与磺酸酯基团的摩尔比为1.5:1时,用全氟己基乙醇亲核取代合成出具有"树枝状"结构的含氟单体,探讨了各步反应影响因素,并用傅里叶变换红外光谱进行了结构表征。利用该"树枝状"新型结构,大量氟链段可稳定聚集于表面,为进一步制备获得具有优异拒水拒油性能的含氟聚合物提供了有利的基本条件。     

单分散聚甲基丙烯酸乙酯的制备与性能研究

活性阴离子聚合为聚合物分子设计和合成提供了一种有效方法.以1,1二苯基己基锂(DPHLi)为引发剂,添加LiClO4络合剂,采用活性阴离子聚合体系制备了单分散聚甲基丙烯酸乙酯(PEMA).考察了聚合温度、引发剂、添加剂等工艺参数对聚合反应的影响规律,并研究了不同pH值聚甲基丙烯酸乙酯的降解性能.     

N,N-二甲氨基甲基丙烯酸乙酯的原子转移自由基聚合

以α-溴代异丁酰乙二醇酯（EBiB）为二官能团小分子引发剂,2,2′-联吡啶（bpy）/CuBr为催化体系,甲醇为溶剂,采用原子转移自由基聚合（ATRP）法合成了两端带Br官能团的聚（N,N-二甲氨基甲基丙烯酸乙酯）（PDMA）大分子引发剂.研究了不同聚合温度（T）及不同设计聚合度（DP）下单体DMA的ATRP反应动力学.结果表明,产物PDMA的分子量随单体转化率（Xa）的增加呈线性增长趋势;其多分散指数（PDI）随反应时间延长变化不大;DMA的ATRP反应在低温反应时为可控/“活性”聚合。     

双甲基丙烯酸聚乙二醇酯的合成及光聚合反应

合成了一系列新型的具有光引发聚合反应活性的单体；不同分子量的聚乙二醇的双甲基丙烯酸酯。单体在紫外光引发条件下进行自由基聚合，生成交联的聚合产物。用＾１Ｈ－ＮＭＲ对单体进行了表征。用ＩＲ对单体和聚合物进行了分析，研究了双甲基丙烯酸二乙二醇酯的聚合反应动力学，测定了聚合活化能。     

偶氮苯端基取代基对ABA三嵌段共聚物性能的影响

研究了偶氮苯端基取代基对ABA三嵌段共聚物性能的影响。合成了3种含不同端基取代基的偶氮苯单体，通过原子转移自由基聚合（ATRP）技术合成了系列ABA型三嵌段共聚物（PMMAzo25-PEG13-PMMAzo25、PEMAzo14-PEG13-PEMAzo14和PNMAzo14-PEG13-PNMAzo14），其分子量可控，分子量分布较窄。该系列共聚物均具有液晶性，其中PMMAzo25-PEG13-PMMAzo25、显示近晶相与向列相，而PEMAzo14-PEG13-PEMAzo14与PNMAzo14-PEG13-PNMAzo14只显示向列相，表明聚合物液晶性强烈依赖于偶氮苯端基取代基。同时研究了聚合物在THF溶液中的光响应行为及偶氮苯端基取代基对其影响。     

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.