Polymer brush coatings for combating marine biofouling

A variety of functional polymer brushes and coatings have been developed for combating marine biofouling and biocorrosion with much less environmental impact than traditional biocides. This review summarizes recent developments in marine antifouling polymer brushes and coatings that are tethered to material surfaces and do not actively release biocides. Polymer brush coatings have been designed to inhibit molecular fouling, microfouling and macrofouling through incorporation or inclusion of multiple functionalities. Hydrophilic polymers, such as poly(ethylene glycol), hydrogels, zwitterionic polymers and polysaccharides, resist attachment of marine organisms effectively due to extensive hydration. Fouling release polymer coatings, based on fluoropolymers and poly(dimethylsiloxane) elastomers, minimize adhesion between marine organisms and material surfaces, leading to easy removal of biofoulants. Polycationic coatings are effective in reducing marine biofouling partly because of their good bactericidal properties. Recent advances in controlled radical polymerization and click chemistry have also allowed better molecular design and engineering of multifunctional brush coatings for improved antifouling efficacies.     

含能材料燃烧过程中热分解化学的研究进展

从模拟燃烧条件、组分相互作用、组分物理状态、分析测试技术等几方面介绍了含能材料燃烧过程中热分解化学研究近几年来的最新进展。着重介绍燃烧热分解中的基元反应对建立推进剂燃烧新型模型的重要性、氧化剂和黏合剂及催化剂之间的相互作用、氧化剂的黏度和相态变化对燃烧和热分解过程的影响。     

基于代理模型的含盐废水多级纳滤系统的过程优化设计

基于道南细孔-介电DSPM-DE模型,开展了工业含盐废水多级纳滤分离系统的代理模型构建与优化研究。首先,利用高维模型表征的数学建模方法,构建与原有纳滤理论模型有高拟合度的高精度代理模型。基于此代理模型,进一步构建膜法分盐工艺中的多级纳滤分离的数学优化模型,并以分离单位质量NaCl的比能耗为优化目标,讨论在给定设计参数的条件下进料液中[Cl^-]/[\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-}]的变化对不同级数纳滤系统的分盐性能及最优操作条件的影响。优化结果显示,进料[Cl^-]/[\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-}]的增加有利于提高NaCl总回收率和降低分盐比能耗。在相同的纳滤膜投资成本下,双级系统在降低能耗方面更胜一筹,与单级系统相比最高可节能5.84%。     

绿色固体推进剂的研究现状及展望

综述了无铅双基系推进剂、可再生TPE推进剂和绿色复合推进剂的研制现状,总结了各类绿色推进剂的特点和发展过程中的技术难题,指出了绿色推进剂的一些技术发展方向,如非铅催化剂的纳米化技术、高效负载技术和复合技术,含能热塑性弹性体的合成及应用技术,硝仿肼(HNF)提纯技术以及新型高能氧化剂合成技术等.     

脂肪族硝基含能化合物撞击感度的QSPR研究

基于定量结构-性质相关性(QSPR)原理,研究脂肪族硝基化合物撞击感度与其分子结构间的内在定量关系。应用遗传函数算法筛选出与撞击感度密切相关的6个参数作为分子描述符;采用多元线性回归方法建立基于该6参数的脂肪族硝基化合物撞击感度预测模型。分别采用内部验证及外部验证的方式对模型性能进行验证,研究结果表明模型具有较高的稳定性、预测能力及泛化性能。     

四嗪类高氮分子及离子含能化合物的研究进展

详细论述了近年来国内外报道的四嗪类高氮分子及离子含能化合物的合成与性能研究,指出部分化合物由于其生成焓高、热稳定性好以及感度低等特点在含能材料领域具有广泛的应用前景.同时还总结了目前四嗪类含能化合物普遍存在的问题及以后的发展方向.     

含能聚氨酯热塑性黏合剂GAP/PBAMO的性能

以聚双叠氮甲基氧杂环丁烷(PBAMO)为硬段,聚缩水甘油醚(GAP)为软段,采用一锅法扩链合成了含能聚氨酯黏合剂(GAP/PBAMO).实验中合成了不同硬段含量的黏合剂,并采用FT-IR、NMR、GPC、XRD、DSC和SEM等对其结构和性能进行了表征.结果表明,硬段质量分数为66.7%时,该热塑性黏合剂具有较好的耐热...     

Restoration of heavily polluted branches of the Shatt Al-Arab river, Iraq

In view of the desire to improve the water quality of the heavily polluted branches of the Shatt al-Arab River at the City of Basrah, it was proposed to maintain effective flushing as well as contracting sewerage system. The present study was conducted in order to examine the water quality of these branches in an attempt to evaluate the effectiveness of the proposed flushing system. It has been found that their waters contained very low levels of dissolved oxygen and relatively high amounts of both COD and BOD₅. The annual average water quality parameters for Basrah Branches were: dissolved oxygen 3.4 ppm; pH 7.67; hydrogen sulphide 1.4 ppm; ammonia 97 μg-at. N l⁻¹; COD 15.9 mg l⁻¹; BOD₅ 12.7 mg l⁻¹; dissolved silicates 202 μg-at. Si l⁻¹; dissolved reactive phosphate 13.4 μg-at. P-PO₄³⁻ l⁻¹; nitrate 10.4 μg-at. N-NO₃⁻ l⁻¹; nitrite 2.1 μg-at. N-NO₂⁻ l⁻¹ and chlorophyll-α 14.3 mg m⁻³. Based on our calculations, it has been concluded that the proposed system is effective, thus within a flushing cycle all of the above mentioned parameters will become within the acceptable values of the Shatt al-Arab water quality. Moreover, this system has no appreciable effect upon the water quality characteristics of the Shatt al-Arab River due to the fact that it discharges a high volume of water annually. However, It has been recommended to dredge the deposited sludge to a minimum depth of 50 cm.     

莫高窟壁画疱疹病害的微观形貌和成分研究

目的研究壁画疱疹盐分或元素的分布规律,为病害治理提供依据。方法使用扫描电子显微镜(SEM)、场发射扫描电子显微镜(FESEM)、X射线能谱(EDS)、X射线衍射(XRD)对疱疹表面的微观形貌、结构及成分进行分析。结果 SEM研究结果表明,疱疹表面被粘土质包裹,其核心部分为无机结晶盐,从部分疱疹剖面可观测到立方体或者近立方体形态的无机盐晶体。FESEM及EDS分析结果显示,大部分疱疹盐结晶的主要成分以Na、Cl元素为主,少部分疱疹中含有Mg、Ca、S等元素。另外,疱疹中Na和Cl以及S和Ca元素具有良好的比例对应关系。结论莫高窟壁画疱疹中的无机盐主要由易溶盐Na Cl构成,少量疱疹还含有CaCl_2、MgSO_4、CaSO_4等可溶盐或中溶盐。