石灰石煅烧产物活性分析

为有效利用小颗粒（~10 mm）石灰石,采用静态煅烧的方法对粒径为0.5~10 mm的石灰石进行煅烧,分析了煅烧温度、煅烧时间、石灰石粒径对煅烧产物活性的影响。结果表明煅烧温度和煅烧时间对石灰活性都有影响,煅烧温度低、时间短,石灰石煅烧不完全,石灰活性差;煅烧温度高、时间长,石灰石又容易过烧,石灰活性依然不高,且温度越高过烧出现的越快;石灰石在950 ℃煅烧60 min得到的产物活性最佳;石灰石粒径对煅烧产物活性有影响,石灰活性并未随着石灰石粒径的增大而呈现单一趋势,大致是先增大后减小,实验中石灰活性最佳的石灰石粒径是2~3 mm。     

石灰石流态化煅烧探索研究

为了高效回收利用废弃石灰石资源,对粒径为0.5~1 mm的石灰石进行了静态煅烧和流态化煅烧实验,比较了其产物活性度的差别,探索流态化煅烧制备高活性度石灰的可行性。实验结果表明：流态化煅烧过程中煅烧时间、煅烧温度对产物活性都有影响。随着温度的升高,得到最佳产物活性的煅烧时间会缩短,在此时间之后,继续煅烧产物活性会下降;相比静态煅烧,流态化煅烧不仅提高了石灰石分解的速率,也提高了产物烧结的速率,大幅度缩短了煅烧时间,同时能够在短时间内得到高活性的石灰。在本实验中,石灰石在1 050 ℃下流化煅烧3 min,得到的产物活性度为338 mL;流态化煅烧过程中,煅烧温度越高,产物活性度对煅烧时间的变化越敏感。     

小颗粒石灰石煅烧制备高活性度石灰的研究

研究了石灰石粒度、煅烧温度和时间对小颗粒石灰石煅烧制备高活性度石灰的影响。结果表明：同工业立窑煅烧块状石灰石相比,用小颗粒石灰石煅烧,能大幅提高石灰的活性度,并能明显缩短煅烧时间、降低煅烧温度。     

煅烧温度对天然水硬石灰物理力学特性影响研究

研究了900~1 150 ℃煅烧温度对寒武纪灰岩制备的天然水硬石灰物理力学特性的影响。利用XRD谱、SEM照片和消化速率表征煅烧产物特性,风吹成粉后检测天然水硬石灰凝结时间和抗折抗压强度。研究表明900~1 150 ℃煅烧温度范围内,煅烧产物主要成分均为游离CaO和β-Ca₂SiO₄,28 d抗压强度均达到天然水硬石灰NHL2的要求。煅烧产物游离CaO含量和消化速率随煅烧温度升高先增大后减小,其中950 ℃时达到峰值。天然水硬石灰凝结时间随煅烧温度升高逐渐缩短,但950 ℃时较1 000 ℃时有明显减少,抗折、抗压强度随煅烧温度变化无明显规律,1 150℃时28 d强度最高。     

活性石灰煅烧条件及其活性评价指标的研究

研究了不同粒径石灰石和煅烧条件对活性石灰的影响。并对比了石灰活性评价的2种指标,即活性度法和碳化率（EDTA）法。 在700 ℃下预热1 h、1 150 ℃下煅烧石灰石,结果表明,粒径为1~2 cm石灰石煅烧后所得石灰活性高于粒径为4~5 cm的石灰活性。在相同的粒径下, 1 150 ℃下煅烧的活性优于700 ℃下预热1 h、1 150 ℃下煅烧的活性。实验表明,采用活性度法和EDTA法测定石灰活性的结果基本一致,都能定性地衡量石灰活性。     

煅烧工艺对轻烧石灰活性度的影响

通过煅烧实验和显微结构观察,研究了煅烧工艺对3种石灰石轻烧后活性度的影响。研究结果表明,对轻烧石灰活性度影响的主要因素有煅烧温度、保温时间、原料粒度和石灰石原矿的显微结构等。     

Al2O3对CaO烧结过程的作用

在较低温度下(≤1600℃)，将添加Al2O3的高纯石灰石在不同煅烧温度下制得了CaO烧结熟科。考察了煅烧温度、保温时间及不同的Al2O3添加量对CaO烧结的作用。试验结果表明，Al2O3的加入使CaO在煅烧过程中得到发育良好的晶粒和撮低的显气孔率。在高于1500℃煅烧的试样中，显气孔率与保温时间之间呈对数关系，这种烧结熟料良好的抗水化性能在于其级低的显气孔率和发育良好的CaO晶粒自身水化活性的降低。     

节能型立窑煅烧小块石灰石的实践与体会

用节能型立窑煅烧30～80mm的小块石灰石,月产生石灰8 000t,石灰CaO含量平均91%,活性度300mL,生过烧率≤8%.获得了可观的经济效益,减少了资源浪费,也降低了生产成本.     

石灰石煅烧对纳米碳酸钙的影响

石灰石是制备纳米碳酸钙的主要原材料,石灰石品质和煅烧质量的好坏,严重影响着纳米碳酸钙的质量.为了深入分析石灰石煅烧温度对纳米碳酸钙生产过程的影响,通过对石灰石在不同温度下进行的煅烧试验,分析其对消化反应及碳化反应各项技术指标的影响.结果表明:1)石灰石煅烧温度过高或煅烧时间过长,对石灰的活性度影响较大,而且对氢氧化钙乳液黏度及碳化反应粒子生成等都产生不同程度的影响;2)石灰石煅烧温度过低,则石灰生烧,石灰石利用率较低,对企业经济效益非常不利.     

水菱镁石制备轻烧MgO粉的煅烧工艺研究

以粒度3～5 mm的水菱镁石为原料,研究了煅烧温度(600、700、800、900和1 000℃)和保温时间(2、3、4和5 h)对轻烧MgO粉活性和热选(分别过孔径0.425、0.150和0.074 mm筛)降CaO率的影响。结果表明:1)轻烧MgO粉的活性随煅烧温度的升高及保温时间的延长均呈先增大后减小的变化趋势,拐点分别为800℃和3 h。2)热选降CaO率随煅烧温度的升高呈先减小后增大的变化趋势,拐点为800℃;随保温时间的延长呈先增大后减小的变化趋势,拐点为3 h;筛孔孔径越大,热选降CaO率越高。3)水菱镁石制备轻烧MgO粉的最佳工艺参数是900℃保温3 h煅烧,然后过0.425 mm筛热选。     

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。