快硬硫铝酸盐水泥浆体-石灰石集料界面的微结构

用XRD层析技术和SEM等手段测定了石灰石集料-硬化硫铝酸盐水泥浆体界面区的组成与结构;用XRD线宽法测定了界面区中AFt的晶体尺寸及其分布。结果表明,界面区的厚度为50μm左右;在石灰石界面区中,AFt晶体和C(?)H_2晶体发生富集,且AFt晶体尺寸较粗大。同时探讨了界面区微结构的形成机理。     

矿物掺合料对水泥浆体-集料界面性能的影响

研究了矿渣、粉煤灰及钢渣三种矿物掺合料对硅酸盐水泥浆体-集料界面区氢氧化钙晶体取向指数及界面区厚度的影响.实验结果表明,矿渣可以降低界面处的Ca(OH)2取向指数,粉煤灰可以降低界面区的厚度,但钢渣会增大界面区氢氧化钙晶体的取向指数及界面区厚度;提高钢渣细度或将钢渣与矿渣、粉煤灰复合可在一定程度上提高含钢渣水泥浆体与集料界面的性能;降低水胶比并提高比表面积,钢渣与矿渣复合水泥浆体与集料的界面区Ca(OH)2取向指数仍较大,但界面区厚度却明显减小.     

轻集料混凝土界面区形成与作用机理研究进展

轻集料混凝土中界面区的组成、结构与性能是决定其性能的关键.针对轻集料混凝土界面区的性能和特点,概括了轻集料混凝土界面区的微观结构特征和相关模型,分析了轻集料混凝土界面区的形成机理,综述了轻集料混凝土界面区对混凝土力学、耐久性能以及体积稳定性能的影响,总结了轻集料混凝土界面区研究中存在的不足和值得深入研究的方向,为轻集料混凝土界面区研究提供参考.     

大坝混凝土的水泥石-石英集料界面结构研究

本文用扫描电镜、X射线能谱分析仪和透射电镜对丰满大坝混凝土的水泥石-石英集料界面区进行分析观察,提出了将该界面区分为与界面平行的三层界面结构模型。对所提出的界面结构模型进行了讨论,并指出Ca(OH)_2晶体簇与钙矾石晶体在其层间未相互穿插生长,有可能是界面区的薄弱环节。     

处理刚玉集料对砂浆界面结构的改进

从微观形貌和水化产物、界面电导特性参数以及孔结构等三方面,研究了处理刚玉集料砂浆中界面区的结构特征,并与硅酸盐水泥熱料集料砂浆、标准砂集料砂浆等界面区的结构进行了比较。结果表明,处理刚玉集料在砂浆中发生了水化反应,水化产物对界面区产生致密作用,使得界面区成为砂浆中一个比较致密的区域。     

硅酸盐水泥熟料-煤矸石混合水泥的界面结构

用环境扫描电镜和能谱仪研究了硅酸盐水泥和硅酸盐水泥熟料-煤矸石混合水泥的界面结构.结果表明:混合水泥中多孔的活化煤矸石和水泥水化产物发生二次反应消耗界面区大量氢氧化钙,生成水化硅酸钙(CSH)凝胶和钙矾石晶体,反应产物层从煤矸石表面向内部逐渐推进,逐渐将煤矸石的开口孔填满,未反应的煤矸石残核仍为多孔状.煤矸石中不同活性的SiO2反应生成的CSH凝胶形态不同,惰性SiO2作为微集料填充在硬化浆体中.煤矸石-反应产物的界面区结构非常致密,减弱了硅酸盐水泥中硬化浆体界面区间隙和氢氧化钙富集造成的不利影响.水化28d内混合水泥中煤矸石本身的强度和煤矸石-水化产物界面的强度均大于水化产物的强度.水化近1 a的混合水泥中以长石类为主的多孔煤矸石残核的强度低于水化产物和煤矸石-水化产物界面强度,以石英为主的密实煤矸石的强度则高于水化产物和煤矸石-水化产物界面强度.     

高性能混凝土构件中碱硅酸反应与延迟性钙矾石形成共存破坏

针对短期服役4 a即开裂破坏的某混凝土构件,采用化学分析、X射线荧光分析、X射线衍射分析和热重分析检测了混凝土芯样浆体的化学和矿物组成,采用岩相法和扫描电镜/能谱分析观测了芯样的微观结构。结果表明:混凝土中部分细集料和少量粗集料发生了明显的碱硅酸反应;混凝土浆体-集料界面区存在大量不同形貌钙矾石异常富集生长,且在浆体-集料界面区发现相伴而生的碱硅酸凝胶和钙矾石产物。混凝土构件破坏是一较为典型的碱硅酸反应与延迟性钙矾石形成共存破坏案例。     

界面区结构对水泥砂浆抗硫酸盐侵蚀性能的影响

使用测长法和Ｘ射线衍射定量法，从二方面研究了界面区结构对水泥砂浆试样抗硫酸盐侵蚀性能的影响。一是将砂浆试样按不同的集料含量进行成型，研究界面区含量对试样抗硫酸侵性能的影响；二是使用具有水硬性表面层和惰性内核复合结构伯深加工处理石英集料以改进砂浆试样中界面区结构，研究界面区结构对试样抗硫酸盐侵蚀性能的影响。     

AFt@SiO2核/壳结构的制备及其性能研究

钙矾石(AFt,3CaO·Al2O3·3CaSO4·32H2O)因其结构中含有大量结晶水而具备了用于制造阻燃材料的潜质.以Al2(SO4)3·18H2O和Ca(OH)2为原料,在200℃条件下通过水热反应进行钙矾石的合成实验,研究了反应物浓度,反应时间,pH值对反应产物的影响,并使用改进的St?ber法在钙矾石晶体表面包覆SiO2壳层,制备AFt/SiO2核/壳结构.采用XRD、SEM、FT-IR、TG等方法对产物表征测试.结果表明:通过水热法可以快速合成出高纯度,结晶性好的钙矾石晶体,pH=10是钙矾石晶体生长的适宜条件;SiO2壳层的包覆能控制AFt的脱水速率,也会降低AFt的含水率.     

卤水侵蚀对水泥粉煤灰浆体微结构影响

采用XRD、29Si和27Al MAS NMR测试技术,研究了粉煤灰掺量和侵蚀龄期对卤水侵蚀下水泥-粉煤灰浆体水化产物相组成、含铝相产物迁移与转变、C-S-H凝胶微结构变化的影响规律.研究结果表明:卤水侵蚀导致浆体Ca (OH)2含量降低,AFm和TAH向AFt转变,同时生成大量Friedel盐,C-S-H凝胶中Al[4]脱出;随粉煤灰掺量增加,浆体中AFt、AFm和TAH生成量降低,C-S-H的MCL和Al[4]/Si增大,Friedel盐生成量先增后减;侵蚀早期,水泥-粉煤灰浆体结构疏松,AFt生成量较纯水泥高,后期浆体致密性提高,抑制卤水侵蚀,AFt生成量较少,C-A-S-H脱铝作用减弱.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Some Large Wood-Boring Beetles in Southeastern USA

Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002–2004. Multiple-funnel traps baited with (−)-α-pinene (released at about 2 g/d at 25–28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus rusticus nubilus, Asemum striatum, Monochamus titillator, Prionus pocularis, Xylotrechus integer, and X. sagittatus sagittatus. Buprestis lineata (Buprestidae), Alaus myops (Elateridae), and Hylobius pales and Pachylobius picivorus (Curculionidae) were also attracted to traps baited with (−)-α-pinene. In many locations, ethanol synergized attraction of the cerambycids Acanthocinus nodosus, A. obsoletus, Arhopalus r. nubilus, Monochamus titillator, and Xylotrechus s. sagittatus (but not Asemum striatum, Prionus pocularis, or Xylotrechus integer) to traps baited with (−)-α-pinene. Similarly, attraction of Alaus myops, Hylobius pales, and Pachylobius picivorus (but not Buprestis lineata) to traps baited with (−)-α-pinene was synergized by ethanol. These results provide support for the use of traps baited with ethanol and (−)-α-pinene to detect and monitor common large wood-boring beetles from the southeastern region of the USA at ports-of-entry in other countries, as well as forested areas in the USA.