大庆油田含油污泥超声波预处理——厌氧产甲烷的探讨

从油田中含油污泥的成分及危害分析入手,阐述了油田含油污泥处理中的超声波与厌氧反应技术。在此基础上,以大庆油田含油污泥作为研究对象,通过实验的方法验证了超声波预处理—厌氧产甲烷的效果。期望能够对油田含油污泥的处理和产甲烷效果的提升有所帮助。     

复合材料用天然植物纤维改性研究进展

天然植物纤维的结构和性能独特,与树脂基体复合仍存在诸多问题。天然植物纤维改性对于提高反应活性、改善其与基体树脂的界面相容性及复合材料的综合性能有重要影响。从天然植物纤维原料的组成、结构及性能分析出发,重点介绍了蒸汽爆破预处理、热预处理、高能辐射预处理、碱预处理、过氧化物预处理和组合法预处理等预处理技术以及酯化改性、接枝共聚、偶联剂改性和其他改性方法,并综述了改性天然植物纤维在复合材料中的研究进展,总结了天然植物纤维改性对复合材料性能的影响,以期为天然植物纤维复合材料的研究提供思路和参考。     

变换炉卸料口接管焊缝裂纹产生的原因及处理

针对变换炉运行一段时间后卸料口接管与变换炉本体焊接处出现的贯穿性裂纹,分析其原因,并在运行过程中采取了一系列预处理措施,有效控制了泄漏;在检修时制定了改造措施,最终消除了这一设备缺陷。     

Improvement of corrosion protective performance of organic coating on low carbon steel by PEO pretreatment

Employing pretreatment is a pressing need for preparing anticorrosive coatings on carbon steels. However, conventional pretreatments are usually based on Cr, P and some other toxic elements, which are harmful to human body. For this reason, green and environmental techniques attract more and more attention. In this paper, plasma electrolytic oxidation (PEO) process was used as a pretreatment to fabricate an underlayer for the organic coating on low carbon steel. The anticorrosive performance of the organic coated samples with and without PEO pretreatment was studied by potentiodynamic polarization, ac/dc/ac electrochemical impedance spectroscopy, salt spray and immersion tests, respectively. Results show that the PEO process produces an oxide layer with porous and rough surface structure on the low carbon steel substrate. The porous and rough PEO layer is beneficial for enhancing the adhesion strength and thickness of the organic topcoatings. The organic coated sample with PEO pretreatment exhibits improved corrosion resistance and longer service life in corrosive environment compared to that without PEO pretreatment.     

Sulfur Versus Non-Sulfur Containing Polyimide Adhesives for Bonding Steel

Due to their superior thermal and chemical stability, polyimides are often used as adhesives in harsh environments. This study examines the effect on bond strength of thioether sulfur in the polyimide backbone. Bonds were made using steel that was believed to catalyze the oxidation of sulfur. In addition, non-sulfur containing polyimides with similar T_g were also studied for comparison. The polymer/metal interface was studied using both the T-peel and wedge tests. No apparent effect was observed in the T-peel test with steel where the T-peel strengths of non-sulfur and sulfur containing polyimides were similar. In the wedge test, however, the sulfur-containing BDSDA/ODA bonded to steel had the smallest initial crack length of 34 mm. However, the BTDA/APB bonds tested in a dry environment had the smallest crack growth. The sulfur-containing BTDA/ASD performed best of the bonds tested in a wet environment. Metal-catalyzed oxidation of sulfur was observed to take place in the steel case, but not to an extent to have a noticeable effect on peel strength.     

用于重金属汞检测的样品前处理方法研究进展

汞是一种对人类和动植物具有相当大毒害的重金属元素。对近年来重金属汞检测的常规前处理方法的研究进展进行了总结,特别列举了近年来新兴的快速前处理方法,并着重展望了重金属汞的检测方向和趋势。对未来在食品及环境中重金属汞的快速前处理方法的建立有良好的借鉴作用。     

两段碳酸钠―氧预处理提高麦草酶水解糖化性能的研究

探讨了不同Na2CO3用量下两段碳酸钠―氧(Na2CO3-O2)预处理对麦草化学成分及酶水解效率的影响。Na2CO3-O2预处理麦草浆料得率随Na2CO3用量增大而下降,木质素脱除率随之增加。预处理后废液的pH值约为9,可有效避免碳水化合物的碱性水解和二次剥皮反应,保持较高的预处理浆料得率。预处理后浆料经过由纤维素酶、木聚糖酶和β-纤维二糖酶组合而成的混合酶水解,当预处理Na2CO3用量(以Na2O计)从12%增至18%时,预处理浆料总糖得率的增加较为显著。经20 PFU/g纤维素酶水解48 h后,总用碱量为18%的两段Na2CO3-O2预处理浆料的酶水解总糖得率为40.8%,总糖转化率为67.0%。     

全无磷低温工艺在电泳前处理中的应用

探讨了无磷低温前处理技术在汽车零部件电泳前处理中的应用,与传统磷化工艺相比,该工艺具有环保、节能等明显的特点,在汽车零部件行业推广具有重要意义。     

酚类环境雌激素的样品前处理技术研究进展

酚类环境雌激素是最为常见的环境雌激素之一,其对人类、环境和生态的影响受到世界范围的关注。介绍了酚类环境雌激素的种类和毒性,详细讨论了各种样品前处理技术,包括溶剂萃取、索氏提取、固相萃取、基质固相分散萃取、微波辅助萃取、加速溶剂萃取、膜萃取、固相微萃取、搅拌棒吸附萃取、分子印迹聚合物萃取、超声辅助萃取、离子液体萃取、浊点萃取、超临界流体萃取等,并对酚类环境雌激素的样品前处理技术进行了总结和展望。     

酸和碱预处理对麻竹酶水解糖化的影响

研究了121℃下硫酸和氢氧化钠预处理对麻竹酶水解还原糖收率的影响,测定了不同预处理液质量分数和预处理时间对还原糖收率的影响,以及预处理后的预处理液中还原糖含量。结果表明,氢氧化钠预处理能显著提高还原糖收率,在氢氧化钠质量分数为2%,预处理时间60min时还原糖收率可达0.367g/gDS。硫酸预处理对还原糖收率的提高幅度不大。但硫酸预处理后的预处理液中还原糖含量较高,在硫酸预处理液质量分数为2%,预处理时间为90min时还原糖收率可达0.152g/gDS。两种预处理方法在121℃下的还原糖收率均高于100℃下的还原糖收率。