Vacuum pyrolysis characteristics of waste epoxy printed circuit boards

Vacuum pyrolysis was employed to dispose scrap brominated epoxy printed circuit boards (PCBs). Pyrolysis characteristics of waste PCBs under normal pressure and vacuum were investigated in this paper. A detailed study on the analysis of the elemental composition of PCBs and the pyrolysis products was performed. The thermal decomposition kinetics was measured by a thermogravimetric (TG) analyzer. The activation energy of pyrolysis under nitrogen atmosphere and vacuum were 193 kJ/mol to 206 kJ/mol and 145 kJ/mol to 165 kJ/mol, respectively. The composition of materials was analyzed by elemental analyzer. The pyrolysis products were analyzed by GC (gas chromatograph), GC-MS (chromatography and mass spectrometry) and FT-IR (Fourier transform infrared spectroscopy). Vacuum helped to increase the yield of pyrolysis oil. The liquid yield of PCBs pyrolysis at 15 kPa and normal pressure were 31.3? and 23.5?, respectively. The main components in pyrolysis oils were phenol, isopropyl-phenol, and their brominated substitution.     

中国英文科技期刊的办刊之路探讨——以《中国化学快报》为例

【目的】通过对《中国化学快报》办刊经验的总结和遇到问题的剖析,探讨中国英文科技期刊的发展之路。【方法】对《中国化学快报》近年的发展历程进行研究,从中发现中国英文科技期刊发展过程的共性问题,并进行提炼总结。【结果】中国英文科技期刊的生存环境已得到较大改善,但在评价体系等大政策的影响下,优质稿件匮乏、人才流失严重、国际显示度低等共性问题依然存在。【结论】在大政策暂时无法突破的现状下,加强内功修炼,寻找适合自身发展的办刊道路,尽快提高中国英文科技期刊的办刊水平。     

浅议化工企业文化建设——以天津渤海化工集团公司为例

企业文化在企业可持续发展的过程中是企业软实力的标志性载体,在提升企业核心竞争力的进程中不可或缺。化工企业的发展更是如此。通过对天津渤海化工集团公司企业文化现状的研究,探讨其企业文化建设的成功因素,分析其不足,以供其他化工企业借鉴和参考。     

《化工基础》教学中的体会

化工基础是高师化学系必修基础课中唯一的紧密联系化工生产实际的课程,本课程在教学中要完成＂从理论到实际＂的转变,就要在明确教学目的、激发学习兴趣,组织好教学内容、抓好＂三个基本＂和采取科学的教学方法、及时做好总结上下功夫,使学生在学习过程中逐步培养分析问题、解决问题和自主学习的能力,这也是化工基础教学中的核心所在。     

Electricity generation and brewery wastewater treatment from sequential anode-cathode microbial fuel cell

A sequential anode-cathode double-chamber microbial fuel cell (MFC), in which the effluent of anode chamber was used as a continuous feed for an aerated cathode chamber, was constructed in this experiment to investigate the performance of brewery wastewater treatment in conjugation with electricity generation. Carbon fiber was used as anode and plain carbon felt with biofilm as cathode. When hydraulic retention time (HRT) was 14.7 h, a relatively high chemical oxygen demand (COD) removal efficiency of 91.7%–95.7% was achieved under long-term stable operation. The MFC displayed an open circuit voltage of 0.434 V and a maximum power density of 830 mW/m3 at an external resistance of 300 ?. To estimate the electrochemical performance of the MFC, electrochemical measurements were carried out and showed that polarization resistance of anode was the major limiting factor in the MFC. Since a high COD removal efficiency was achieved, we conclude that the sequential anode-cathode MFC constructed with bio-cathode in this experiment could provide a new approach for brewery wastewater treatment.     

Extraction and stripping kinetics of copper （Ⅱ） by N902 using single drop technique

The kinetics of extraction and stripping of copper （Ⅱ） was investigated by the single drop technique with a new extractant N902 （a derivative of the salicylal-doxime） and the rate equations of extraction and stripping were derived, respectively. The apparent activation energies of extraction and stripping were estimated to be 20.14 kJ/mol and 30.0 k J/mol.     

酯水解的动力学常数测定实验的改进

对酯水解的动力学常数测定实验进行改进,通过使用带恒温装置的紫外可见分光光度计,在一定pH值和恒温条件下测定具有三脚架型的二乙烯三胺锌配合物催化磷酸双酯BNPP水解的吸光度随时间的变化,进一步求算出催化磷酸双酯水解的二级速率常数,有助于学生掌握测定配合物催化酯水解的动力学参数。     

木棉的化学成分及药理作用的研究进展

综述了木棉的化学成分及药理作用的研究进展,该植物含有挥发性成分、三萜类及黄酮类等化合物,具有显著的抗菌、抗炎、抗肿瘤及肝损伤保护等药理作用。     

A novel colloid probe preparation method based on chemical etching technique

Several fundamental problems in hydrophobic force measurements using atomic force microscope （AFM） are discussed in this paper. A novel method for colloid probe preparation based on chemical etching technology is proposed, which is specially fit for the unique demands of hydrophobic force measurements by AFM. The features of three different approaches for determining spring constants of rectangular cantilevers, including geometric dimension, Cleveland and Sader methods are compared. The influences of the sizes of the colloids on the measurements of the hydrophobic force curves are investigated. Our experimental results showed that by selecting colloid probe with proper spring constant and tip size, the hydrophobic force and the complete hydrophobic interaction force curve can be measured by using AFM.     

彩色海芋在上海地区引种栽培技术初探

春季种植时间越晚,彩色海芋的生育期越短,易使其品质下降。用适当的栽培基质可以生产出品质优良的切花和观赏价值高的盆花。合理密植可提高单位面积的切花产量而不会影响质量。合理应用生长延缓剂可使植株矮化,延长现蕾至开花的天数,提高盆花的观赏价值。细菌性软腐病是彩色海芋的主要病害,选用抗性强的品种、严格控制土壤条件、结合药剂防治等策略可以减少其发生。