多相物质粉末衍射的物相检索

讨论了多相物质粉末衍射的物相检索问题，介绍了XRDS的物相检索软件。这是一种智能型的物相检索程序，考虑了测试数据的不确定度，以及粉末样品和块状样品衍射图谱各自的特点，不仅注意到实际样品中微量物相存在的可能，也注意到块状样品结构有序性的可能。XRDS能够帮助材料工作者同时检出样品中所含的多种物相及其含量，操作简单、结果可靠。     

基于BP网络的设备状态分类器的设计

介绍了在Matlab6.5的神经网络工具箱中，开发基于BP网络的设备状态分类嚣的方法和要点，给出了仿真结果，并以实例验证了该分类器在设备故障诊断中的有效性。     

化工机械与环境的和谐发展

针对化工机械对地球资源、能源等消耗过快、过多及污染环境等问题,提出生产绿色化工机械的设想.即通过加强化工机械的绿色设计、绿色制造、绿色包装、生产过程中废弃物循环利用及绿色管理、自主创新等措施,来实现化工机械与环境和谐发展.     

西北地区水资源现状与可持续利用对策的探讨

中国的水资源问题在西北地区尤为突出.西北地区生态环境脆弱,资源丰富,如何在发展经济的同时实现人与自然的和谐共处,已成为人们日益关心的话题.随着国家西部大开发战略的进一步推进,特别是实施西部大开发的近五年,切实采取有效措施以实现西部地区水资源的可持续利用,已经逐渐成为人们的共识.从分析西北地区水资源现状入手,根据西北地区水资源的特点,提出西北地区水资源可持续利用的对策①加大地下水资源勘查力度,查清水资源储量;②综合利用,科学规划,加强水资源的合理配置与调控;③开源与节流并举,尤其要重视节流;④充分利用天然地下库容调蓄水资源;⑤完善相关法律和法规的建设,强化监督管理加强和完善水资源法规建设,建立健全水资源管理体系.通过以上措施的实施将有利于解决西北地区水资源的严重短缺问题.     

基于决策树技术的日前市场清算电价预测

以澳大利亚昆士兰州电力市场为背景,采用决策树技术,建立了提前日的电力市场清算电价预测模型。详细介绍了决策树技术的原理及其在电价预测中的实现方法,考虑了非电价因素对电价预测的影响。实际结果表明该方法具有良好的预测效果和直观性。     

绿色理念的内涵拓展与绿色图书馆建设

绿色图书馆是图书馆学的一个新的研究方向和发展趋势.文章首先深刻挖掘绿色内涵的本质,阐述正确理解绿色图书馆的含义,接着探讨了绿色图书馆建设的要素取向,从而明确了现阶段发展绿色图书馆的必要性.     

Restraining the associations of anthracene fluorophore by chemically linking to poly(methyl methacrylate)

Associations (dimer or aggregate) of anthracene (An) fluorophores tend to interrupt the monomer emission and reduce the quantum yield (Φ_PL); therefore, poly(methyl methacrylate) (PMMA) chain was used in this study to chemically link to anthracene and to block the mutual associations among the anthracene fluorophores. With this aim, the target polymers were prepared by anionic polymerizations with 9,10‐dibromoanthracene/s‐butyllithium as initiating system to proceed polymerizations of methyl methacrylate (MMA) directly or in the presence of 1,1‐diphenylethylene (DPE). Use of DPE before addition of MMA produces stable initiating anionic species and avoids potential side reactions during polymerization; however, it also introduces four β‐phenylene rings around the central anthracene ring, which interfere with the corresponding emission pattern and reduce the Φ_PL (32%) value due to potential interactions between phenylene rings and anthracene. On the contrast, polymerization without participation of DPE results in polymer with central anthracene ring directly connected to two PMMA chains, which gives clean vibronic emission pattern with limited association emissions and enhanced Φ_PL (52%) value. Physical blending of anthracene by PMMA is less efficient to restrain the associations and results in a film of lower Φ_PL (20%). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis of polyurethane resins and its improvement on dimensional stability and finishing performances of medium‐ and small‐diameter softwoods

This study analyzed the effects of polyurethane (PU) resin treatments on surface homogeneity, dimensional stability, and finishing performances of medium‐ and small‐diameter softwoods produced in Taiwan. Two‐pack PU resins were prepared by combing short castor oil‐modified alkyd resin serving as a polyol with polymeric 4,4′‐diphenymethane diisocyanate (PMDI) serving as a hardener, by the molar ratio of NCO/OH+COOH of 1.2. Four types of short oil‐modified alkyd resins with different polyhydric alcohols (glycerin and pentaerythritol) and polybasic acids (phthalic anhydride and isophthalic acid) were synthesized. Three kinds of medium‐ and small‐diameter softwoods, including China fir, Taiwanina, and Japanese fir with a diameter of 10–15 cm were obtained from Hui‐Sun Forest Station, Taiwan. The wood coating of nitrocellulose (NC) lacquer including sanding sealer and top clear was used. Results show that the surface hardness, homogeneity, moisture excluding efficiency, and antiswelling efficiency of woods were enhanced by PU resin treatments. Among all the PU resins, the isophthalic acid and pentaerythritol‐containing PU resin (IPA‐P‐MDI) achieved the best improved efficiency on dimensional stability of woods. Results of two types of finishing procedure, i.e. NC lacquer sanding sealer plus top clear and top clear only, applied onto the PU‐treated woods revealed that the hardness, adhesion, and durability of NC lacquer films on the PU‐treated wood were superior to those of untreated one, especially for top clear finishing alone. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008