Studies of the stability of thermoplastic-modified bismaleimide resin

The stability of bismaleimide—o,o′-diallyl bisphenol A (BMI—DABA) blends modified with high-performance amorphous thermoplastic bisphenol A polysulfone (PSF), polyether ketone (PEK-C), and polyether sulfone (PES-C) bearing a phthalidylidene group has been studied by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The extent of stability of thermoplastic components has been compared with the area of the endothermic peak that appears within the glass transition region for thermoplastic component in cured blends aged at temperature below the glass transition temperature (T_g). The stability of thermoplastic can be improved by the formation of semi-interpenetrating polymer networks (semi-IPNs). The stability of thermoplastic with higher T_g is more easily controlled. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1965–1970, 1997     

无卤阻燃PA10T力学性能及热稳定性研究

采用一种次膦酸金属盐阻燃剂(FR-Phosphite)对聚对苯二甲酰癸二胺(PA10T)进行阻燃改性。研究了阻燃剂含量对改性PA10T力学性能的影响,并分析了不同阻燃剂含量时阻燃PA10T的热降解行为。结果表明,随着阻燃剂含量的增加,阻燃PA10T材料的拉伸强度呈现先上升后下降的趋势;阻燃剂FR-Phosphite降低了PA10T的初始降解温度。     

北海炼油异地改造项目建设工作回顾

为落实党中央、国务院西部大开发战略,加快实施广西北部湾经济区发展规划建设,中国石化集团公司与广西壮族自治区政府达成合作协议,同意启动北海炼油异地改造石油化工项目(以下称:北海项目)。北海项目筹备组2009年7月21日组建,2010年3月3日项目土建开工。项目总     

高校有机实验室三废的处理浅析

文章探讨了高校有机实验室产生的三废,指出了其产生的污染和危害,分析了现存的管理上的问题,并提出相应的解决方法和措施以减少污染的产生。     

造纸系统中杀菌剂与胶黏物控制剂的协同杀菌作用研究

造纸系统中不可避免的会有微生物的存在和污染,对造纸生产过程和成品纸质量产生不良影响。评价了杀菌剂纸保308和两种胶黏物控制剂胶控物I和胶控物Ⅱ单独使用及复配使用的抑菌效果,研究结果显示三种试剂单独使用时,纸保308的抑菌效果最好,而纸保308和胶控物I按照2：l的比例复配,抑菌效果比各试剂单独及纸保308和胶控物Ⅱ复配的抑菌效果都好,为筛选造纸工业中杀菌和胶黏物控制俱佳的复配物提供实验数据。     

Dynamic Stabilization of DNA Assembly by Using Pyrrole-Imidazole Polyamide

We used N-methylpyrrole (Py)-N-methylimidazole-(Im) polyamide as an exogenous agent to modulate the formation of DNA assemblies at specific double-stranded sequences. The concept was demonstrated on the hybridization chain reaction that forms linear DNA. Through a series of melting curve analyses, we demonstrated that the binding of Py−Im polyamide positively influenced both the HCR initiation and elongation steps. In particular, Py−Im polyamide was found to drastically stabilize the DNA duplex such that its thermal stability approached that of an equivalent hairpin structure. Also, the polyamide served as an anchor between hairpin pairs in the HCR assembly, thus improving the originally weak interstrand stability. We hope that these proof-of-concept results can inspire future use of Py−Im polyamide as a molecular tool to modulate the formation of DNA assemblies.     

Advanced Surface of Fibrous Activated Carbon Immobilized with FeO/TiO2 for Photocatalytic Evolution of Hydrogen under Visible Light

FeO-doped TiO₂ nanoparticle photocatalysts were immobilized onto the surface of fibrous activated carbon (ACF) via a sol-gel process. As an adsorbent and photocatalyst, FeO-TiO₂ on immobilized ACFs (FeO-TiO₂/ACF) greatly improved the photocatalysis rate of hydrogen production as compared with pure TiO₂ and ACF-TiO₂ under UV irradiation and visible light. The addition of ACFs surface significantly reduced the photogenerated pairs of electrons-hole recombination, thereby promoting the photocatalysis action of doped photo-metal oxides of FeO-TiO₂. Co-doping of FeO onto the lattice of the TiO₂ approach can improve the absorption activity of visible light through photo-metal oxide of TiO₂ and further enhance hydrogen production under visible light. The photocatalytic fabrics (FeO-TiO₂/ACF) were effortlessly split out from the experimental solution for re-utilization and exhibited high stability even after five complete regeneration cycles.     

金属改性的TiO2纳米管对光催化性能的影响

对TiO_2纳米管进行改性可进一步提高光催化性能,TiO_2纳米管的改性方式主要有三种:非金属离子掺杂、金属改性和半导体复合。本文主要介绍金属改性TiO_2纳米管的制备方法和光催化性能,金属改性分为金属离子掺杂和贵金属负载,金属离子掺杂主要介绍Fe和Zr,贵金属负载介绍Ag、Au、Pt。改性后的TiO_2纳米管有效地抑制了光生载流子的复合,因此具有比纯TiO_2纳米管更好光催化性能,降解有机污染物的效率更高。     

Enhancing low-temperature energy harvesting by lead-free ferroelectric Ba(Zr0.1Ti0.9)O3

The energy-harvesting ability of the lead-free ferroelectric Ba(Zr,Ti)O₃ was investigated and greatly enhanced using the Kim novel electrothermodynamic cycle for low-temperature application. Ba(Zr,Ti)O₃ was synthesized with a Zr:Ti ratio of 10:90 (BZT10) by hot-press sintering, which exhibited a mix relaxor-ferroelectric behavior. For power generation using the Kim cycle with low and high temperatures of T_L = 25°C, T_H = 120°C, the most optimized temperature pattern occurred for a heating time of 12.5 s and a cooling time of 22.5 s. Under these conditions, the electric field increased during the novel isodisplacement process, and the displacement variation in the isoelectric step reached the highest value and maximized the BZT10 cycle loop area. Applying these conditions while lowering T_L to 20°C, an energy density N_D = 504 mJ/cm³ was achieved. This value is the highest obtained energy density in a practical test for lead-free ferroelectric bulk material in the BaTiO₃ family.