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1.
碱矿渣赤泥水泥   总被引:12,自引:0,他引:12  
利用一种复合高效固体碱性能激发剂激发矿渣和赤泥,成功地研制出具有优良性能的碱矿渣赤泥水泥。当水泥中矿渣与赤泥之比为70:30、固体碱性激发剂的掺加量为14%时,该水泥具有正常的凝结时间、良好的体积安定性和高的强度;初凝62min,凝凝95min,对抗矿渣赤泥水泥其它工程性能的研究还表明,该水泥具有优于同标号硅酸盐水泥的抗干综性能,抗碳化,耐冻融,和抗化学侵蚀性能。  相似文献   

2.
碱矿渣水泥因具有能耗低、二氧化碳排放低、性能优越等优点成为近年来建筑材料领域的研究热点.但其泛碱现象,影响了碱矿渣水泥的实际应用.本文旨在将纳米二氧化硅掺入碱矿渣水泥中,抑制其泛碱.研究了纳米二氧化硅掺入方式对碱矿渣水泥抗压强度和泛碱的影响,利用扫描电镜(SEM)、水化热测定、汞压入法(MIP)等技术分析了纳米二氧化硅对碱矿渣水泥泛碱的抑制机理.结果表明,纳米二氧化硅最佳掺入方式为超声分散.此外,掺加纳米二氧化硅可有效促进碱矿渣水泥的水化进程及水化程度,改善碱矿渣水泥硬化浆体微观结构,优化碱矿渣水泥硬化浆体的孔径尺寸分布,提高硬化浆体密实度,增加碱矿渣水泥的抗压强度,从而有效抑制碱矿渣水泥泛碱.  相似文献   

3.
石膏矿渣水泥具有低水化热、良好抗化学侵蚀性能等优点,是一种低碳绿色胶凝材料。为了明确原材料对石膏矿渣水泥混凝土抗硫酸盐侵蚀性能的影响,对比研究了不同化学组成及活性矿粉制备的石膏矿渣水泥混凝土的强度发展及抗硫酸钠侵蚀性能。结果表明:提高矿粉中Al2O3含量可以有效提高石膏矿渣水泥混凝土早期3 d强度;石膏矿渣水泥混凝土在硫酸钠环境下表现出强度软化型劣化;提高水泥用量、降低水灰比可以有效提高低活性矿粉制备的石膏矿渣水泥混凝土的抗硫酸钠侵蚀性能,但不利于高活性矿粉制备的石膏矿渣水泥混凝土的抗硫酸钠侵蚀性能。研究为低活性矿粉制备石膏矿渣水泥混凝土及其寿命预测提供试验数据支撑。  相似文献   

4.
赤泥-碱矿渣水泥及其制品的研究   总被引:14,自引:0,他引:14  
本文研究了不同碱激发剂对碱矿渣水泥强度的影响,确定了以硅酸钠和石膏作为复合激发剂,且掺量分别为3%和5%时碱矿渣水泥的强度最高,并分析了激发剂的作用机理。同时研究了赤泥对碱矿渣水泥强度的影响,并研究了利用赤泥-碱矿渣水泥作为基本胶凝材料制造的免烧砖和轻质墙体材料的性能。  相似文献   

5.
抗碳化性能是混凝土耐久性的重要方面.以水玻璃与氢氧化钠(NaOH)为碱组分,粒化高炉矿渣为胶凝材料,研究了碱矿渣水泥的抗碳化性能,并分析了碱矿渣水泥易于发生碳化的主要原因.结果表明:与硅酸盐水泥相比,碱矿渣砂浆的碳化程度较大,碳化未引起碱矿渣水泥石干燥收缩的增加.碱矿渣水泥基胶凝材料硬化体碳化程度较大的主要原因是其水化产物不存在Ca(OH)2、硬化体孔溶液的高碱性及较大的干燥收缩.  相似文献   

6.
本文研制了低水灰比高强度碱矿渣水泥。抗压强度高达350MPa以上。分析了工艺条件对水泥性能的影响以及强度与水化程度,孔隙率、孔分布的关系。比较了碱矿渣水泥和波特兰水泥的界面性能和耐蚀性。并对碱矿渣水泥的水化产物进行了x-射线衍射分析、红外光谱分析、差热分析、扫描电镜观察及能谱分析。  相似文献   

7.
碱矿渣水泥化学收缩研究   总被引:1,自引:0,他引:1  
研究了矿渣的种类、细度以及碱组分种类、碱溶液浓度等对碱矿渣水泥化学收缩的影响.结果表明,当碱组分为NaOH时,碱矿渣水泥28d龄期的化学收缩约为6~10ml/100g,与硅酸盐水泥(7~9ml/100g)的相当;当碱组分为水玻璃时,其收缩量约为3~6ml/100g,比硅酸盐水泥的小.  相似文献   

8.
模拟高旄生废物碱矿渣水泥基固化体的性能研究   总被引:3,自引:0,他引:3  
研究了用初压成型和振动成型工艺制造的碱矿渣水泥固化体的某些性能。结果表明,用碱矿渣水泥基材料固化模拟高放射性废物是可行的。采用初压成型工艺制造的碱矿渣水泥固化体,28d抗夺强度达117.3MPa,孔隙率为9.64%,且固化还具有良好的抗冲击性能和较好的核素浸出率。  相似文献   

9.
碱矿渣水泥是以碱金属化合物与工业废渣配制而成的一种节能型水硬性胶凝材料。这种水泥具有早强、高强、快硬、抗冻、耐热及抗侵蚀等优良性能,受到国内外水泥界的高度重视。碱矿渣水泥除用于常规土木建筑工程外,还可在其他特殊领域如道路工程中使用。  相似文献   

10.
宋学锋  邓倩倩 《硅酸盐通报》2018,37(12):4018-4021
研究了铝酸盐水泥种类、掺量及养护温度对碱激发矿渣砂浆早期泛霜的抑制效果.结果表明:(1)加入适量铝酸盐水泥能够明显抑制碱激发矿渣砂浆的早期泛霜;(2)铝酸盐水泥对碱激发矿渣泛霜抑制效果与体系的化学组成有关,而与铝酸盐水泥种类无关,当体系硅铝比为3.02~3.14、钠铝比0.54~0.56时泛霜抑制效果最好;(3)低温养护下,铝酸盐水泥抑制碱激发矿渣泛霜效果明显;(4)红外光谱(FTIR)分析结果证实铝酸盐水泥的加入,促使Al3+进入[SiO4]4-中,取代Si4+,形成的电负性为固定Na+提供了可能.  相似文献   

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12.
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.  相似文献   

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14.
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.  相似文献   

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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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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。  相似文献   

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