浙江舟山岛近岸海水富营养化水平分析

根据2010年10月~2011年3月舟山岛近岸海水COD、无机氮（DIN）和磷酸盐（DIP）调查数据,对舟山岛近岸水体富营养化进行了分析和评价。结果表明舟山岛海域处于严重的富营养化状态,富营养化状态指数中COD占优势,其次为DIN,这两者起到了绝对性作用。水体营养等级基本为富营养化,且在舟山岛海域藻类生长基本上是受氮限...     

海安县地表水环境污染问题分析及防治对策探讨

文章对海安县地表水环境存在的污染问题展开深入研究,并就相关问题针对性的提出了防治对策。     

离子对反相高效液相色谱法测定猪硫酸软骨素的含量

目的：采用离子对反相高效液相色谱法测定猪硫酸软骨素的含量。方法：采用Inertsit-ODS-SP色谱柱（4.6×150 mm,5μm）,流动相：乙腈—0.006 mol.L-1辛烷基磺酸钠溶液（15：85）,磷酸调pH至3.5,流速：0.8 mL.min-1,测定波长：195 nm,进样量：20μL。结果：该方法在质...     

PDMBR和SFDMBR用于污水处理的运行特性比较

采用孔径37 μm涤纶滤布制作膜组件,构成一体式自生动态膜生物反应器(SFDMBR),和以高岭土为预涂剂,组成预涂动态膜生物反应器( PDMBR),研究两者用于处理模拟生活污水的运行特性.结果表明,PDMBR抗膜污染效果比SFDMBR的好,PDMBR和SFDMBR的运行周期分别为13、11d,两者的膜通量基本稳定在28 L·m-2·h-1.当DO质量浓度大干0.5 mg·L-1时,DO对PDMBR和SFDMBR的COD去除几乎没有影响,对COD的击除率均在85％以上;PDMBR和SFDMBR的EPS浓度分别稳定在70、75 mg·L-1.     

生物质焦分形维数计算

采用压汞法的实验数据,计算两种分形模型下生物质焦样的分形维数。其中根据Menger海绵模型计算得到的分形维数Dm的值在2．7～3．1之间,基于热力学关系的分形模型计算得到的分形维数Dr的值在2．7～2．9之间。分析认为第二种模型更好的描述了焦样的孔隙结构,Dr的值比Dm的值更为合理。实验结果表明,分形维数与生物质种类有关,树叶焦样的分形维数整体上大于稻壳焦样的分形维数。生物质焦样的平均孔径与分形维数有关。总的来看,同一生物质焦样的分形维数随着平均孔径的增大而减小。     

掺氟聚磷酸钙生物陶瓷的合成与特性研究

在新型生物陶瓷聚磷酸钙中掺入氟离子,研究氟对聚磷酸钙陶瓷的晶体结构以及化学键的影响。本研究以氟化氨作为掺杂试剂,通过掺杂不同含量的氟,研究其物理性能的变化,如弯曲强度、气孔率等。研究表明,氟元素的引入可以改变聚磷酸钙的晶型和力学性能;掺入一定量氟的聚磷酸钙陶瓷具有在骨组织工程上作为骨修复材料在临床应用的可能性。     

Highly active and selective Cu/SiO2 catalysts prepared by the urea hydrolysis method in dimethyl oxalate hydrogenation

Cu/SiO₂ catalysts have been successfully prepared via urea hydrolysis method. The catalysts have been systematically characterized by X-ray diffraction, high-resolution transmission electron microscopy, N₂-physisorption and H₂ temperature-programmed reduction. The results demonstrated the presence of copper nanoparticles and their high dispersion on the SiO₂ support. Catalysts with different copper loadings were prepared, and their performances in the hydrogenation of dimethyl oxalate to ethylene glycol were studied. A 100% conversion of dimethyl oxalate and maximum 98% selectivity of ethylene glycol were reached with 15.6 wt.% copper loading at 200 °C and 2 MPa. Furthermore, under the same reaction conditions, the catalyst can maintain the selectivity of 90% when the reduction temperature reduced from 350 °C to 200 °C. The high activity and selectivity over the catalyst may be ascribed to the homogenously distribution of copper nanoparticles on the large surface.     

Solid superbase derived from lanthanum–magnesium composite oxide and its catalytic performance in the knoevenagel condensation under solvent-free condition

We report for the first time the synthesis of a novel solid superbase that was derived from lanthanum–magnesium composite oxide and KOH through thermal treatment. The as-prepared material shows base strength (H_–) above 26.5 and is a high-efficiency catalyst for solvent-free Knoevenagel condensation at room temperature. The results of the present study open up a new dimension for the use of composite oxides as new support materials in the synthesis of superbases.     

环形气隙中长直载流导线磁场的级数解及应用

本文首先采用分离变量法推导了位于定、转子间均匀环形气除中单根长直载流导线磁场的级数解；然后介绍了应用该级数解计算电机电枢反应磁场、永磁场的方法；最后应用该级数解获得了考虑定、转子曲率影响的均匀气隙电机不饱和主电抗与谐波电抗表达式。比较表明，当电机气隙和定、转子半径可比拟（尤其对于极对数较大的情况）时，考虑与不考虑定、转子曲率两种计算方法给出的不饱和主电抗、谐波电抗之间存在巨大的差异。考虑定、转子曲率时的计算结果更加接近实测结果。     

The formation of β‐polypropylene crystals in a compatibilized blend of isotactic polypropylene and polyamide‐6

Compatibilized polypropylene (PP)/polyamide (PA6) blends with and without β nucleating agent (β‐NA) are prepared, and are designated as Blend‐0.3 and Blend‐0, respectively. The melting and crystallization characteristic of the blends crystallized under different cooling rates and different crystallization temperatures are studied. It is observed that high β‐PP content can be developed in Blend‐0.3 only at slow cooling rates (<5°C/min), whereas high α‐PP content is formed at fast cooling rates. Isothermal crystallization analysis of Blend‐0 indicates that PA6 is an effective NA for α‐PP in the lower temperature range, whereas the α‐nucleating effect disappears in the higher temperature range. Blend‐0.3 can, therefore, be viewed as a system containing both α‐ and β‐NAs, simultaneously. PA6 is competing with β‐NA in inducing PP crystallization. Under the normal injection of Blend‐0.3, the melt will be cooled through the higher temperature that favors the effectiveness of β‐NA rapidly because of the faster cooling rate. However, the α‐nucleation effect from PA6 predominate at the lower temperature. This explains the difficulty in obtaining high β‐PP content in Blend‐0.3 from injection molding. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers