镍铁渣粉用作水泥混合材的性能研究

为了研究水泥-镍铁渣粉胶凝体系的性能,本文分析了镍铁渣粉化学组成、粒度分布和微观形态,并通过水泥性能试验检测了镍铁渣粉对水泥性能的影响。研究结果表明,实验室球磨机制备的镍铁渣粉在颗粒球形度和粒度级配曲线方面较辊磨粉磨微粉更优,镍铁渣粉对水泥安定性影响较小,对水泥与减水剂的适应性影响也不大,但会增大水泥标准稠度需水量,延长凝结时间,降低强度和胶砂流动性能。     

废弃混凝土磨细粉对水泥性能的影响

利用废弃混凝土制备全组分混凝土细粉,研究细粉对水泥标准稠度需水量、凝结时间、胶砂强度和化学结合水的影响,并采用XRD、TG-DSC等测试技术,研究其对水泥水化产物的影响.研究结果表明:细粉不影响水泥的标准稠度需水量,但缩短了水泥的凝结时间;低掺量下细粉对胶砂强度影响不大,但掺量超过10％时,胶砂强度随着掺量的增大不断降低;细粉的掺入虽然促进了浆体中水泥的水化,但却降低了浆体的总水化程度;细粉中的石灰石可以与水泥水化产物发生反应,生成单碳水化铝酸钙.     

废弃砂浆粉对水泥物理力学性能的影响

研究了废弃砂浆粉对水泥物理力学性能的影响,测试了标准稠度需水量、凝结时间、流动度和强度.结果表明:废弃砂浆粉的掺加导致水泥的标准稠度需水量增加,水泥的凝结时间总体降低,水泥净浆的流动度及流动度损失均呈降低趋势,而减水剂与水灰比对水泥净浆的流动度及流动度损失有较大影响.废弃砂浆粉掺加量的多少将直接影响到水泥砂浆的强度,掺量越大,水泥砂浆强度损失越严重,而掺量低于10%时,水泥砂浆仍具有较高的抗压强度和抗折强度.微观结构特征表明,废弃砂浆粉掺量在一定范围时,水泥砂浆体系中产生钙矾石与C-S-H凝胶较多,体系结构密实性好.     

Ⅱ级粉煤灰对水泥性能的影响及应用

通过对水泥强度、凝结时间等物理性能的测定，研究了不同掺量的粉煤灰对水泥性能的影响。结果表明：随着粉煤灰掺量的增加，水泥-粉煤灰体系的 3 d抗压强度呈线性较低趋势；粉煤灰单掺效果＜粉煤灰与矿粉复合效果＜矿粉单掺效果；在保证强度的前提下，水泥中掺加适当的粉煤灰有助于改善水泥与外加剂的适应性，且对标准稠度用水量和凝结时间的影响不大；建议粉煤灰替代水泥的掺加量不大于 5%；粉煤灰替代矿粉的掺加量不大于 33%。     

废混凝土细粉料对水泥物理力学性能的影响

研究了废混凝土细粉料对水泥标准稠度需水量、凝结时间、流动度、强度和干燥收缩率等物理力学性能的影响。研究结果表明,废混凝土细粉料对水泥物理力学性能具有重要影响,使得水泥浆体标准稠度需水量增大,初凝和终凝时间缩短,水泥砂浆流动度降低,3 d和28 d抗压强度及抗折强度显著降低;但废混凝土细粉料能降低水泥砂浆早期干燥收缩率,改善水泥砂浆早期干燥收缩性能。但一定掺量范围内,废混凝土细粉料仍能确保水泥具有较好的物理力学性能。     

废混凝土细粉料对水泥物理力学性能的影响研究

研究了废混凝土细粉料对水泥标准稠度需水量、凝结时间、流动度、强度和干燥收缩率等物理力学性能的影响。研究结果表明,废混凝土细粉料对水泥物理力学性能具有重要影响,使得水泥浆体标准稠度需水量增大,初凝和终凝时间缩短,水泥砂浆流动度降低,3 d和28 d抗压强度及抗折强度显著降低;但废混凝土细粉料能降低水泥砂浆早期干燥收缩率,改善水泥砂浆早期干燥收缩性能。在一定掺量范围内,废混凝土细粉料仍能确保水泥具有较好的物理力学性能。     

除氯处理的PAC废渣的细度和掺量对水泥性能影响的研究

采用水泥基本性能标准检测方法研究了经化学-煅烧法除氯处理的聚氯化铝废渣（简称复合除氯PAC废渣）的细度和掺量对标准稠度需水量、凝结时间、强度等水泥性能的影响。研究结果表明：随着复合除氯PAC废渣的细度越来越细,水泥的标准稠度需水量越来越大,水泥的凝结时间也逐渐缩短,对水泥的强度增强效果越来越弱。复合除氯PAC废渣的实用细度为粒径大于80 μm的粒子质量分数为1.5%~2.5%;随着实用细度的加湿复合除氯PAC废渣掺量的逐渐增加,水泥28 d抗压强度出现先增强后降低现象,在掺量为17%时,水泥28 d抗压强度的增长率出现临界值。     

丙烯酸钙/镁对水泥水化进程的影响

研究了不同丙烯酸钙/镁配比及掺量、引发剂、促进剂、交联剂掺量对水泥水化进程的影响。通过进行标准稠度需水量、凝结时间、抗压强度测试,找出其对水泥水化进程的规律;利用XRD、水化热、DSC-TG等测试手段分析不同配比及掺量下的丙烯酸钙/镁对水泥水化物相组成的影响。研究结果表明:随着不同配比下的丙烯酸钙/镁掺量的增加,水泥标准稠度需水量是增加的,当掺量较低时,相同掺量的不同配比下丙烯酸钙/镁的标准稠度有一定的差异,但当掺量超过2.5%时,配比对标准稠度需水量的影响不是主要的;丙烯酸钙/镁降低水泥早期强度,但对水泥的后期强度发展有利。由水化热分析出改性水泥试样的放热速率低于空白水泥试样。     

城市生活垃圾焚烧灰渣作为水泥混合材的试验研究

针对生活垃圾焚烧灰渣的组成和特性,进行了垃圾焚烧灰渣作为水泥混合材的试验研究.结果表明:掺入垃圾焚烧灰渣的水泥,随垃圾焚烧灰渣掺量的增加,水泥凝结时间逐渐延长.标准稠度需水量增加,水泥的强度呈下降趋势;水泥矿物的水化产物能有效固化垃圾焚烧灰渣中的重金属,掺垃圾焚烧灰渣水泥的重金属浸出浓度均低于浸出毒性标准限值.     

干法脱硫渣对水泥性能的影响

研究干法脱硫渣对水泥标准稠度、凝结时间、强度的影响,实验结果表明,干法脱硫渣对水泥标准稠度需水量有降低的作用,对水泥凝结时间有缩短的作用,对水泥3d抗压强度有提高作用,对水泥28d强度有降低作用。     

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。