OCO污水处理工艺在城市污水处理中的应用

介绍OCO工艺及其对城市污水处理的效果。普通城市污水经过该工艺处理之后 ,可以达到我国污水排放标准 ,还可以将所处理的污水经过三级处理之后 ,作为工业用水进行再利用。OCO工艺具有除氮除磷功能强、自动化程度高、运转方式灵活、占地少、出水水质稳定等特点 ,适用于高浓度工矿企业废水和城市生活污水的处理     

扩链剂在PVC树脂生产中的应用

讨论了常见扩链剂的功能及在聚氯乙烯树脂生产中的应用。     

湿法磷酸装置三废治理新进展

湿法磷酸装置排放的三废对环境危害较大 ,尤其是废水治理长期以来尚未得到全面控制。阐述了某新建的湿法磷酸装置从工艺流程上通盘考虑 ,采用多次串级利用 ,实现污水全封闭、零排放的流程 ,达到了由清到浊、由冷到热 ,多次利用、自身消化 ,实现平衡、避免污染的目的 ,并介绍了废气和废渣治理的新措施。指出应坚持精心操作和维护 ,巩固已取得的三废治理成果     

Synthesis,characterization, and thermal properties of phosphorus‐containing,wholly aromatic thermotropic copolyesters

A series of phosphorus‐containing, wholly aromatic thermotropic copolyesters from acetylated 2‐(6‐oxide‐6H‐dibenz〈c,e〉〈1,2〉oxa phosphorin‐6‐yl)‐1,4‐dihydroxy phenylene, p‐acetoxybenzoic acid, terephthalic acid, and isophthalic acid were prepared by melting polycondensation. The structure and basic properties of the polymers, such as the glass‐transition temperature (T_g), melting temperature (T_m), thermal stability, crystallinity, and liquid crystallinity, were investigated with Fourier transform infrared, elemental analysis, differential scanning calorimetry (DSC), thermogravimetric analysis, wide‐angle X‐ray diffraction, and hot‐stage polarizing optical microscopy. The copolyesters had relatively high T_g values ranging from 183 to 192°C. The T_m values obtained from DSC curves for samples P‐20 and P‐25 were 290 and 287°C, respectively (where the number in the sample name indicates the molar fraction of the phosphorus‐containing monomer in the reactants). The initial flow temperatures of other samples observed with hot‐stage polarizing microscopy were 271–290°C. The 5% degradation temperatures in nitrogen ranged from 431 to 462°C, and the char yields at 640°C were 41–52%. All the copolyesters, except P‐40, were thermotropic and nematic. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1278–1284, 2002     

Improvement of Microwave Loss Tangent and Tunability of Ba0.55Sr0.45TiO3/MgO Composites Using the Heterogeneous Precipitation Method

Ba_0.55Sr_0.45TiO₃/MgO composites were successfully prepared by the heterogeneous precipitation method and their structural, surface morphological, tunable properties, and dielectric properties at microwave frequency were systemically investigated. Compared with the sample prepared by the traditional solid-state method, the sample prepared by the heterogeneous precipitation method exhibits a smaller grain size, more uniform microstructure, higher tunability, and lower microwave loss, and these properties are very beneficial to the development of the microwave tunable devices application. Moreover, the effects of La₂O₃ doping on the dielectric and tunable properties of BST/MgO composites are investigated. The result shows that the La³⁺-doped sample has higher tunability and lower microwave loss than the undoped one.     

Synthesis and self-assembly of hyperbranched polyester peripherally modified by touluene-4-sulfonyl groups

In this paper, hyperbranched polyesters (HPs) were synthesized in the molten state from 2,2-bis(hydroxymethyl) propionic acid (bis-MPA) and 2-ethyl-2-hydroxymethyl-1,3-propanediol (TMP) using acid catalysis. The modified hyperbranched polyesters were obtained through the chemical modification of the hyperbranched polyester cores by substituting a controlled fraction of the terminal hydroxyl groups with touluene-4-sulfonyl chloride using triethylamine (TEA) as an acceptor of HCl. The resultant polyesters were characterized by ¹H NMR, ¹³C NMR, FT-IR, UV and GPC and their self-assembly behaviors were investigated. The results revealed that self-assembled structures could be formed in selected solvents (trichloromethane/acetone or trichloromethane/n-hexane).     

环氧丙烷生产工艺进展

综述了近年来环氧丙烷合成工艺的新进展,包括对现有环氧丙烷生产工艺的革新、直接氧化法、光催化环氧化等方法,并对各种方法的特点和发展前景进行了讨论.     

一种无线传感器网络链式传输分簇路由协议

由于周围环境对无线传感器网络(WSNs)的影响,在布设到特殊环境下时会产生信号的衰减与损耗,导致通信不畅。针对此问题,提出一种以LEACH路由协议为基础适应特殊环境(长直空间)的新型路由算法。本算法采用链式传输,即从内部逐一将信号传输给距空间最外端且距基站位置较近的簇头,克服了内部节点死亡过快的问题。同时簇内采用链式传输并且改进簇头阈值与成簇半径,减小了能量消耗,提高了稳定性,克服了LEACH算法的不足。     

四种杀菌剂对枸杞黑果病的防治效果

枸杞黑果病是枸杞产区的主要病害．发病后造成黑花、黑蕾和黑果，使枸杞产量降低，品质变劣。为探明四种杀菌剂对枸杞黑果病的防治效果及最佳剂量，2003年对下述四种杀菌剂进行了田间药效对比试验，调查防效结果如下：20％三苯基醋酸锡WP450～281g／hm^2(以有效成分计，下同)，20％氟硅唑EC21．08g／hm^21．5％噻霉酮EW16、88～21．08g／hm^2、40％氟硅唑EC450g／hm^2和70％甲基托布津WP787．5g/hm^2对枸杞黑果病防效均在88．25％以上。经LSD检验各处理间防效无显著差异。     

洗涤剂用4A沸石工业的回顾及展望

4A沸石具有软化水质的作用，是全球公认的优良的代磷助剂。介绍了洗涤剂用4A沸石在世界各地的发展历程和现状，指出了国际洗涤剂用4A沸石的发展趋势，并就国内洗涤剂用4A沸石提出了发展建议。