微生物絮凝剂产生菌的筛选及其所产絮凝剂的特性研究

微生物絮凝剂是一种由微生物产生的具有絮凝活性的高分子化合物，具有絮凝沉降性能好、安全、无毒一系列等优点，对水中的悬浮颗粒、金属离子以及废水脱色等方面都具有独特效果。是一类极具发展前景的环境友好型水处理剂，因此研究和开发微生物絮凝剂具有广阔的应用前景。     

道康宁的汽车发动机密封解决方案

发动机作为汽车的心脏部分对于整车的性能是至关重要的,汽车发动机的"三漏"(漏水、漏油和漏气)现象总令发动机生产商头痛, "三漏"看似平常,不值一提,然而它直接影响着汽车的正常使用、工作效率以及汽车发动机的外观洁净程度.选择合适的密封材料和工艺防止"三漏",是汽车发动机设计工艺人员必须考虑的一个重要问题.     

Preparation and Characterization of a Novel Hybrid Copolymer Hydrogel with Poly（ethylene glycol） Dimethacrylate, 2-Hydroxyethyl Methacrylate and Layered Double Hydroxides

This paper describes the fabrication, characterization and properties of a novel hybrid poly(ethylene glycol) (PEG) based hydrogel via in situ polymerization. The hybrid hydrogel was fabricated by free-radical redox polymerization using ammonium persulfate (APS) and N, N, N??, N??-tetramethylethylenediamine (TEMED) as initiators and N, N??-methylene bisacrylamide (BIS) as cross-linker at 60°C. To create a hybrid hydrogel, 0.2% (mass fraction) of MgAl layered double hydroxide (LDH) was added to the aqueous solution by ultrasonic dispersion. The physicochemical properties of hybrid hydrogel under vacuum freeze-drying processing were characterized by Fourier transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA) and scanning electron microscopy (SEM), while swelling kinetics and gel content were calculated. Swelling degree in distilled water varied from 94%?C125% with a gel mass fraction of 83%?C91%. SEM images showed that the micron pore size of hydrogel could be adjusted within the range of several micrometers by changing the cross-linker mass fraction from 2% to 10% (based on glycol). The results showed that the hybrid hydrogels exhibited excellent physicochemical behavior and might be a promising material for applications in tissue engineering and drug delivery.     

铁路危险货物集装箱运输中的包装新问题

危险货物所用包装材料的种类很多，而塑料则是其中应用最为广泛的一种。如各种形式的塑料桶、袋、瓶等。塑料的主要成分是树脂。树脂是一种高分子化合物，它随着所处环境温度的不同，呈现出3种物理状态：玻璃态、高弹态、粘流态(见下图)。     

车蜡ABC

车蜡用于在车漆表面盖上蜡质保护层（蜡层）,蜡层能够抵挡酸雨、紫外光、沙石等对车漆的伤害。打蜡可以使车漆保持光泽,防止结构复杂的车漆因外在因素而老化。最早的车蜡是从石油中提取的石蜡,如今的车蜡主要成分是聚乙烯乳液或硅酮类高分子化合物,并含有油脂和添加剂。