碳纤维表面改性及对其复合材料性能的影响

采用γ射线辐照法、电化学聚合法改性碳纤维表面,研究了以三缩四乙二醇为接枝单体,在不同的辐照剂量下辐照处理碳纤维,以及电化学聚合衣康酸改性碳纤维。利用扫描电子显微镜、X光电子能谱仪、电子万能试验机研究了处理前后的碳纤维的表面形貌、复合材料的断面形貌、表面化学组成及复合材料层间剪切强度(ILSS)的变化。研究结果表明,2种处理方法都能有效提高碳纤维表面活性,与环氧树脂的浸润性提高,复合材料断面纤维拔出明显减少。在200kGy的辐照剂量下处理得到的碳纤维与环氧树脂复合材料的ILSS的提高幅度最大,达到31.2%。同时经电聚合处理后的碳纤维与环氧树脂复合材料的ILSS的提高幅度要大于经γ射线辐照处理后的试样,达到40%。     

含碳纳米管上浆剂的制备及对碳纤维/环氧树脂复合材料界面的影响

首先采用"Friedel-Crafts"酰化反应制备羧基化多壁碳纳米管(MWCNTs)并将其与环氧树脂、丙酮混合制成含MWCNTs的上浆剂,然后用该上浆剂浸渍碳纤维制备碳纳米管/碳纤维多尺度增强纤维。采用扫描电镜研究了上浆处理对碳纤维表面形貌的影响,采用短臂梁剪切测试方法研究了含碳纳米管的上浆剂对碳纤维/环氧树脂复合材料层间剪切强度(ILSS)的影响。结果表明,碳纳米管在上浆剂中的分散状态直接影响纤维表面碳纳米管分布的均匀性;与未浸渍的碳纤维相比,含碳纳米管上浆剂浸渍后的碳纤维/环氧树脂复合材料的ILSS提高了34.33%。通过上浆剂红外光谱表征、纤维束表面浸润性测试及ILSS试样端口形貌的观察,分析了层间增韧机理。研究表明,碳纤维束表面浸润性的提高以及碳纤维/环氧树脂界面处化学键合作用增强,是ILSS提高的主要原因。     

γ射线辐照对碳纤维表面接枝改性的影响

为提高碳纤维/环氧树脂复合材料的界面粘结性能, 采用γ射线共辐照接枝方法对碳纤维表面改性, 利用X光电子能谱仪(XPS)、 扫描电子显微镜(SEM)、 电子万能材料试验机, 研究了在缩乙二醇丙酮溶液和环氧氯丙烷丙酮溶液中经200 kGy剂量的γ射线辐照接枝后, 碳纤维的表面化学元素及官能团组成、 表面形貌、 复合材料剪切断面形貌及其层间剪切强度(ILSS)的变化。研究表明, 缩乙二醇类接枝液的接枝效果较理想, 碳纤维接枝率达7%; 辐照处理碳纤维表面O/C比值和含氧官能团含量增加, 以此制备的碳纤维/环氧复合材料的ILSS提高, 最大提高率达31.2%; 同时还发现辐照接枝后的碳纤维表面粗糙度增大。     

电化学氧化对高强高模碳纤维表面结构及力学性能的影响

利用循环伏安多重扫描法分析了不同电解质的氧化能力及其氧化特点,讨论了在表面氧化处理中不同电解液体系对高模高强碳纤维力学性能的影响,提出了适合高强高模碳纤维表面处理的工艺条件,并通过Raman光谱、XPS与SEM的表征,研究了电化学氧化对高强高模碳纤维表面结构及力学性能的影响。研究结果表明,与NH₄H₂PO₄溶液相比,用NH₄H₂PO₄与CH₃COONH₄复合的电解质溶液对碳纤维进行表面处理,能大幅度提高纤维表面含氧官能团,而且纤维表面sp²杂化碳原子相对含量也较多,在提高了碳纤维/环氧树脂复合材料层间剪切强度(ILSS)的同时,还较好地保持了高强高模碳纤维本体力学性能。当CH₃COONH₄与NH₄H₂PO₄的物质的量之比为2:1时,碳纤维/环氧树脂复合材料的ILSS与未处理纤维相比提高了168%,而碳纤维拉伸强度却下降很小,此复合电解质溶液是一种较为理想的对高强高模碳纤维进行表面改性的电解质体系。     

Effects of Υ-ray irradiation on carbon fiber surface graft modification

为提高碳纤维／环氧树脂复合材料的界面粘结性能,采用7射线共辐照接枝方法对碳纤维表面改性,利用X光电子能谱仪（XPS）、扫描电子显微镜（SEM）、电子万能材料试验机,研究了在缩乙二醇丙酮溶液和环氧氯丙烷丙酮溶液中经200kGy剂量的Υ射线辐照接枝后,碳纤维的表面化学元素及官能团组成、表面形貌、复合材料剪切断面形貌及其层间剪切强度（ILSS）的变化。研究表明,缩乙二醇类接枝液的接枝效果较理想,碳纤维接枝率达7％;辐照处理碳纤维表面O／C比值和含氧官能团含量增加,以此制备的碳纤维／环氧复合材料的ILSS提高,最大提高率达31．2％;同时还发现辐照接枝后的碳纤维表面粗糙度增大。     

阴离子型水性环氧树脂制备及其应用性能EI北大核心CSCD

通过己二酸与环氧树脂反应,并用KOH中和制备的阴离子型水性环氧树脂(AAEK)具有良好的亲水性,可作为碳纤维上浆剂对碳纤维表面进行修饰,将处理后的碳纤维与环氧树脂复合制备成碳纤维/环氧树脂复合材料。利用红外、扫描电镜、原子力显微镜、吸附实验、万能材料试验机对AAEK改性后的碳纤维和AAEK改性后的碳纤维/环氧树脂复合材料进行表征和测试。结果表明,AAEK的最佳上浆质量分数和吸附量为1.0%和3 mg/g;AAEK处理后的短丝碳纤维在环氧树脂中的分散性得到明显改善;AAEK在碳纤维表面的吸附是介于单分子层和多分子层之间的吸附过程,符合Freundlich吸附等温模型;AAEK处理后的碳纤维单丝断裂强度有少量增加;AAEK改性后的碳纤维/环氧树脂复合材料的弯曲强度和层间剪切强度(ILSS)相比于改性前分别提高了168%和139%。     

阴离子型水性环氧树脂制备及其应用性能EI北大核心CSCD

通过己二酸与环氧树脂反应,并用KOH中和制备的阴离子型水性环氧树脂(AAEK)具有良好的亲水性,可作为碳纤维上浆剂对碳纤维表面进行修饰,将处理后的碳纤维与环氧树脂复合制备成碳纤维/环氧树脂复合材料。利用红外、扫描电镜、原子力显微镜、吸附实验、万能材料试验机对AAEK改性后的碳纤维和AAEK改性后的碳纤维/环氧树脂复合材料进行表征和测试。结果表明,AAEK的最佳上浆质量分数和吸附量为1.0%和3 mg/g;AAEK处理后的短丝碳纤维在环氧树脂中的分散性得到明显改善;AAEK在碳纤维表面的吸附是介于单分子层和多分子层之间的吸附过程,符合Freundlich吸附等温模型;AAEK处理后的碳纤维单丝断裂强度有少量增加;AAEK改性后的碳纤维/环氧树脂复合材料的弯曲强度和层间剪切强度(ILSS)相比于改性前分别提高了168%和139%。     

γ-射线辐照Armos纤维对AFRC界面性能的影响

为改善Armos纤维和环氧树脂间的界面结合性能,采用对环氧树脂/丙酮溶液浸泡的Armos纤维进行γ-射线辐照改性处理,探索辐照剂量对其芳纶纤维增强复合材料(AFRC)界面性能的影响.研究结果表明:在辐照剂量200～1000kGy,AFRC的层间剪切强度(ILSS)和界面剪切强度(IFSS)均增加,且500kGy界面强度较未处理的提高幅度最大;经γ-射线辐照处理的芳纶纤维,表面氧含量有大幅度提高,使得纤维表面活性增大;辐照处理后纤维表面较未处理的纤维表面粗糙度有所增加;纳米硬度仪测试AFRC横断面纤维、界面和基体的纳米硬度,表明辐照可以提高复合材料的硬度.     

阴离子型水性环氧树脂制备及其应用性能

通过己二酸与环氧树脂反应,并用KOH中和制备的阴离子型水性环氧树脂(AAEK)具有良好的亲水性,可作为碳纤维上浆剂对碳纤维表面进行修饰,将处理后的碳纤维与环氧树脂复合制备成碳纤维/环氧树脂复合材料。利用红外、扫描电镜、原子力显微镜、吸附实验、万能材料试验机对AAEK改性后的碳纤维和AAEK改性后的碳纤维/环氧树脂复合材料进行表征和测试。结果表明,AAEK的最佳上浆质量分数和吸附量为1.0%和3 mg/g;AAEK处理后的短丝碳纤维在环氧树脂中的分散性得到明显改善;AAEK在碳纤维表面的吸附是介于单分子层和多分子层之间的吸附过程,符合Freundlich吸附等温模型;AAEK处理后的碳纤维单丝断裂强度有少量增加;AAEK改性后的碳纤维/环氧树脂复合材料的弯曲强度和层间剪切强度(ILSS)相比于改性前分别提高了168%和139%。     

石墨纤维阳极氧化表面处理的研究

本文研究了PAN基石墨纤维在四种铵盐电解液中阳极氧化表面处理的工艺条件.用SEM和XPS技术分析了处理前后纤维表面形态的变化,通过复合材料的层间剪切强度(ILSS)对表面处理前后石墨纤维与环氧树脂之间界面粘结强度的改善进行了评价.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

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.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

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.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.