Studies on the interfacial adhesion between functionalized polypropylene and polyamide 1010

The interface behavior of polyamide 1010 (PA1010) and polypropylene (PP) was studied. In order to improve their interfacial adhesion, functional PP was prepared by means of grafting glycidyl methacrylate (GMA) on PP main chains and used instead of plain PP. Several technological characterizations were performed here on their interfaces. ESCA was used to confirm that some kind of reaction occurred between end groups of PA1010 and epoxy species of PP-g-GMA. The peel test was adopted to measure interfacial adhesion. It was found that the fracture energy of interfaces between PA1010 and PP-g-GMA was dramatically increased with the content of GMA. Their interfaces were observed as being blurred by using SEM and TEM and a crack that could be seen in the case of the interfaces of the PA1010 and the plain PP disappeared.

Crystal structure and drawing-induced polymorphism in poly(aryl ether ether ketone). IV

A new crystal modification induced by strain and denoted as form II exists alongside the dominant form I structure in the uniaxially oriented poly(ether ether ketone) (PEEK) and the related polymers. The crystal structure of form II for PEEK is also found to possess a two-chain orthorhombic packing with unit cell parameters of a equal to 0.475 nm, b equal to 1.060 nm, and c equal to 1.086 nm. More extended and flattened chain conformation of form II relative to that of form I is expected to account for an 8% increase in c-axis dimension, which is attributed to the extensional deformation fixed in situ through strain-induced crystallization during uniaxial drawing. Annealing experiments suggest that form II is thermodynamically metastable and can be transformed into more stable form I by chain relaxation and reorganization at elevated temperature without external tension. This strain-induced polymorphism exists universally in the poly(aryl ether ketone) family. (C) 1999 John Wiley & Sons, Inc.

Detection of hydrazine, methylhydrazine and isoniazid by capillary electrophoresis with a 4-pyridyl hydroquinone self-assembled microdisk platinum electrode

Capillary electrophoresis (CE)/electrochemical detection (EC) for the simultaneous detection of hydrazine, methylhydrazine, and isoniazid has been developed with a 4-pyridyl hydroquinone self-assembled microdisk platinum electrode. Such an electrode has very high catalytic ability for hydrazines and they could be detected even at 0.0 V. The responses for hydrazine, methylhydrazine, and isoniazid are linear over 3 orders of detected concentration and of magnitude of 0.2-400 mu M, 0.2-400 mu M, 0.5 mu M-2 mM, with correlation coefficients of 0.9998, 0.9991, and 0.9982, respectively. And they could be detected to levels of 0.1, 0.1 and 0.2 mu M, respectively. This modified electrode was found to be very stable and reproducible when continuously used as detector for capillary electrophoresis for period of at least 4 weeks with no apparent loss of response. (C) 1999 Elsevier Science B.V. All rights reserved.

双盘工作电极参比电位采样快扫伏安方法

报道一种双铂盘工作电极、相应的毛细管参比电极和竖直式电化学池设计并用于快速循环伏安测量.双工作电极包括一个常规工作电极,一个辅助工作电极.后者在使用中接地,仅提供参比电位来控制工作电极的电位.参比毛细管尖端安设在接近辅助工作电极的位置上;用0.3mm直径Pt盘工作电极,在电位扫描速度高达10kV/s都可以得到类似于100%iR补偿的伏安曲线,而不必使用iR补偿电路.本文围绕高扫速伏安法中工作电极电位的准确控制问题做了一些初步的探讨.

多核Nd-Al双金属配合物对丁二烯的聚合 Ⅳ.烷基铝种类的影响

利用多核Ｎｄ－Ａｌ双金属配合物可单独引发双烯烃聚合的特点，考察了烷基铝种类对丁二烯加聚过程的影响，并与一般混合稀土催化体系进行了比较．烷基铝对活性体催化活性的影响与其用量有关，低ｎ（Ａｌ）／ｎ（Ｎｄ）值时，活性次序为：ＡｌＭｅ３，ＡｌＥｔ３，ＨＡｌＢｕｉ２＞Ａｌ（Ｃ８Ｈ１７）３＞ＡｌＢｕｉ３；高ｎ（Ａｌ）／ｎ（Ｎｄ）值时，活性次序相反：ＡｌＭｅ３，ＡｌＥｔ３，ＨＡｌＢｕｉ２＜Ａｌ（Ｃ８Ｈ１７）３＜ＡｌＢｕｉ３．烷基铝链转移作用强弱次序为：ＨＡｌＢｕｉ２≥ＡｌＥｔ３＞ＡｌＢｕｉ３＞ＡｌＭｅ３＞Ａｌ（Ｃ８Ｈ１７）３．根据聚丁二烯微观结构与其分子量的关系，可将烷基铝对聚丁二烯顺式含量的影响分为３类：（１）ＡｌＥｔ３和Ａｌ（Ｃ８Ｈ１７）３；（２）ＨＡｌ－Ｂｕｉ２和ＡｌＢｕｉ３；（３）ＡｌＭｅ３．所得结果有助于对稀土催化定向聚合过程的深入了解.

THE COMPATIBILITY AND MORPHOLOGY OF CHITOSAN-POLY(ETHYLENE-OXIDE) BLENDS

Thermal behavior and morphology of blends prepared by solution casting of mixtures of chitosan and poly( ethylene oxide) were studied by means of differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The preliminary results indicate that both melting point and crystallinity depend on the composition of the blends, and that they exhibit minimum values when the blend contains 50% chitosan. From the prediction of melting point depression analysis, the compatibility of the blends shows a transition at this specific composition. This conclusion was further confirmed by observation of the morphology.

沸石基质中Eu~(3+)的还原及Eu~(2+)的稳定性

低温弱还原条件下,在沸石基质中获得了稳定的Eu~(2+)。借助程序升温还原(TPR)技术考察了沸石中Eu~(3+)→Eu~(2+)还原温度及价态转换途径。通过穆斯堡尔谱讨论了价态转换过程中,铕离子在沸石笼结构中的配位环境及其与沸石骨架的相互作用。光电子能谱和荧光光谱数据表明,Eu~(2+)在沸石基质中价态是稳定的。

巯基—聚吡咯薄膜修饰电极的制备及其电化学性能

通过将巯基乙酸作为一种支持电解质,将巯基固定在导电聚吡咯薄膜电极上,从而制得巯基—聚吡咯薄膜修饰电极,该修饰电极保持了巯基的螯合性能,并具有良好的稳定性。对水溶液中的重金属离子具有很好的吸附作用,其灵敏度与未修饰的玻碳电极相比,测汞离子时电沉积提高了3倍,化学吸附时提高了近5倍。并对其吸附机理进行了初步的探讨,证明了其对汞离子的吸附为不可逆的产物弱吸附。

规范化管理高科技高效益企业

规范化管理高科技高效益企业中国科学院成都生物研究所王海燕中共成都市委组织部张松中科院成都生物研究所于１９８８年开始创办药厂，药厂产值六年翻了六番，原始投资增值数百倍。如今，药厂已更名为地奥制药公司，成为拥有净资产２亿多元、年利税１亿元的集高科技、新产...

目前俄罗斯图书馆界对《ББК》分类法中马列主义及相关类目的修订处理

<正>1992至1993年间,笔者两次赴俄罗斯莫斯科及毗邻地区访问并工作.在前后七个月的时间内,有机会考察了解俄国图书馆界的一些情况.在与俄方交谈中得知,目前俄国各图书馆正根据“有关文件精神”对前苏联的图书分类法《ББК》的各种版本进行修订.笔者希望阅读这“有关文件”的要求被委婉谢绝后,却有幸借到莫斯科郊区城市谢尔布霍夫某一基层群众图书馆正在实施修改工作用的一册手改本《ББК》分类法.虽然这是用于群众图书馆的一种简本,对于了解苏联解体后俄罗斯政治变化对俄图书分类法

食用资源昆虫的利用及研究进展

综述了食用资源昆虫的含义、利用、营养保健作用及其研究进展,以期为食用资源昆虫的进一步开发提供参考资料。

“跨界融合子” 审理对我们的启示:审稿案例分析

通过分析典型审稿案例 ,揭示审稿活动的科学本质。 科学的可批评性使审稿成为可能和必要。审稿人应首先审核 论文中结果的可重复性条件。划清科学实践与经验的界限是 正确审稿的必要理论准备 ,论文结果的价值判断应以 “材料和 方法” 的可靠性为前提。学术期刊编辑应充分重视审稿人的意 见 ,防止 “轰动效应” 干扰自己的正常判断力。审稿活动中的 “马太效应” 可以成为推进科学进步的动力 ,使已有科学理论体 系的 “潜能” 得到充分揭示 ,使真正具有生命力的科学新芽在脱 颖而出时已扎根深土 ,格外茁壮。

中小型专业图书馆图书、档案、情报一体化后业务管理模式思考——从我馆谈起

阐述图书、档案、情报一体化管理模式在中小型专业图书馆的可行性,并以中国科学院成都生物研究所信息中心为例,探讨一体化业务管理模式和最终实现这种模式对业务管理的要求。

孔子与恐龙化石

《史记·孔子世家》记载 :吴国攻陷了越国的首都会稽 ,获得了一枚大骨头 ,要用一辆车才装得下。吴国使者到鲁国访问 ,乘便询问孔子“什么骨头最大”。孔子回答说 :当年大禹王召集群神到会稽 ,防风氏违命迟到 ,大禹杀了他 ,并陈尸示众 ,他的一节骨头要用一辆车才装得下 ,这应算?