菱镁制品吸潮返卤影响的研究

影响菱镁制品吸潮的关键因数是氯离子含量的高低。若氯离子含量高,则吸潮返卤的可能性就大,氯离子含量低,则制品的吸潮返卤的影响就小。采用莫尔法[1]测定制品中氯离子的含量,借此获得界定菱镁制品发生吸潮返卤时氯离子含量的临界值,从而预测菱镁制品吸潮返卤的可能性,在生产实践中具有显著的经济和社会效益。     

利用脱硫石膏生产模具石膏的关键因素分析

在脱硫过程中由于原料、工艺的不同,会造成脱硫石膏在颗粒形态、杂质等方面有所不同,影响石膏制品的性能。采取粉磨的措施、利用脱硫石膏与天然石膏混合使用的方法可以改善颗粒级配;采取水浸过滤的方法去除脱硫石膏中所含的可溶性盐、飞灰等有害杂质,有利于延长石膏浆体的搅拌时间,改善浆体的流动性能。     

氯氧镁胶凝材料吸潮返卤泛霜的研究进展

氯氧镁胶凝材料(MOC)是一种具有广泛应用潜力的无机材料,而吸潮、返卤和泛霜等缺点阻碍其推广应用.本文在分析MOC制品表面潮湿、挂水珠和出现白霜原因的基础上,阐明了"吸潮"、"返卤"和"泛霜"等概念的内涵及其相互关系;重点分析了MOC中游离MgCl2产生的原因;对当前防治吸潮、返卤和泛霜的方法和措施进行了综合评述;介绍了国内外吸潮、返卤和泛霜的检测方法和成果;最后指出了MOC吸潮、返卤和泛霜的未来研究方向.     

我国脱硫石膏与脱硫建筑石膏质量问题及成因分析

通过调查和试验,发现我国脱硫石膏水溶性盐、氯离子含量超标,二水硫酸钙含量偏低,严重影响了脱硫石膏及其下游制品的品质。落后的煅烧工艺及设备,导致了脱硫建筑石膏质量参差不齐、凝结时间缩短、缓凝剂对建筑石膏失效、抗压抗折强度降低等现状。指出必需研究出与煅烧设备及烧制成品相匹配的一系列煅烧工艺,才能指导厂家生产出质量较好的脱硫建筑石膏。     

处理工艺对脱硫石膏晶体形态的影响研究

脱硫石膏的晶体颗粒形态是影响石膏制品性能的重要因素之一.脱硫石膏的颗粒级配较差,采取粉磨的措施或者利用脱硫石膏与天然石膏混合使用的方法可以改善;采取蒸压处理的方法,有利于解决脱硫石膏晶体尺寸较大、颗粒级配较差的问题,同时可以生成高强度的a-半水石膏.     

利用硅钙渣、水泥、粉煤灰等改善脱硫石膏制品性能的研究

以脱硫石膏、水泥、高铝粉煤灰及其提铝后硅钙渣为主要原料,制作脱硫石膏制品,并对其性能进行测试。测试结果表明:在脱硫石膏制品中添加水泥可以改善其力学性能以及耐水性能,且水泥的添加量应控制在20%以内;添加硅钙渣的石膏制品与纯石膏相比,密度下降,强度提高,吸水率基本保持不变,软化系数增加,且随着硅钙渣添加量的增加,密度下降加剧;粉煤灰的添加使得制品耐水性提高,但强度降低,吸水率和软化系数提高;生石灰掺量5%时制品强度最高;在粉煤灰、硅钙渣、生石灰总量一定的条件下,改变粉煤灰和石灰石的量,石膏制品的干抗折和抗压强度在10%左右时强度最低。     

氯氧镁板材制备工艺优化研究

氯氧镁材料制品作为一种代木、节能、环保的建筑材料越来越受到关注,但是较长时间以来该制品在实际应用中耐水性、返卤以及力学性质等方面的不佳表现未能得到很好的改善。本文通过量化其摩尔比、改性剂以及养护条件进行改性试验研究,经多种标准检测和表征分析实现了企业的硅镁加气混凝土轻质隔板力学强度优异、解决其吸潮返卤、耐水性差等弊病。     

脱硫石膏应用技术现状及其发展趋势

对国内外脱硫石膏应用技术现状进行总结和分析,结论认为用脱硫装置生产出符合标准和规范的、可直接应用的、成为与天然石膏相同等值的原料和产品是利用脱硫石膏的关键。将脱硫石膏与其他天然和化学石膏统一规划,完善建筑石膏产品的应用技术和规范,是促进脱硫石膏综合利用的决定因素。利用脱硫石膏制备复合胶凝材料和制品,具有很好的前景。     

首届脱硫石膏综合利用专题研讨会11月中旬在上海召开

国家近年采已对二氧化硫排放严格控制，全国各大电厂脱硫设备相继运行，而电厂又一废弃物-脱硫灰渣不断产生。据悉，到2010年，国内脱硫机组总容量将达到40000-50000MW，即年产纯度85％以上的烟气脱硫85027吨，为及时掌握了解脱硫灰渣利用技术与信息，中国城乡建设粉煤灰利用技术开发中心联合中国硅酸盐学会石膏专业委员会于11月15日在上海召开年会暨脱硫石膏综合利用专题研讨会。来自全国燃煤电厂、石膏厂商、设计科研、设备制造商等单位百余名代表赴会．“脱硫石膏的资源化利用与分析”、“利用宝钢电厂脱硫石膏配制粉刷石膏砂浆的试验研究”等十余篇优秀论文作者进行了宣讲，大会对脱硫石膏和石膏制品的生产工艺，设备亦作了介绍，并组织去宝钢脱硫石膏综合利用基地参观，会议取得了圆满成功。     

菱镁制品泡水氯离子析出量与强度关系的研究

研究了MgO—MgCl2-H2O三元体系水化产物泡水后氯离子的析出量及强度的关系。分别分析了水浴温度对氯离子析出量的影响、氯离子析出量与强度的关系、抗返卤剂对氯离子析出量及软化系数的影响。通过试验发现抗返卤剂的加入能够显著降低菱镁制品在水浴中氯离子的析出量,提高了制品的强度和软化系数。     

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.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

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.     

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.     

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。