热力采油条件下粉煤灰改善铝酸盐水泥石耐高温性能及作用机理研究

硅酸盐类水泥石经热力采油后耐高温性能变差是诱导套管损坏和水泥环层间封隔失效的关键原因.和普通硅酸盐水泥相比,铝酸盐水泥具备更好的耐高温特性,但却存在温度敏感性强、高温养护后强度不高的缺点.实验通过在铝酸盐水泥中掺入粉煤灰并采用高能球磨方法重新制备水泥材料,采用XRD和SEM等测试方法,对粉煤灰材料改善铝酸盐水泥石耐高温特性和作用机理进行分析.结果表明:通过球磨方式加入粉煤灰材料不仅有利于水泥石低温强度的发展,而且能够明显改善铝酸盐水泥石的长期耐高温特性;其组分SiO2和铝酸盐水泥水化产物C3AH6发生反应,并生成C3ASH4等稳定相,使水泥石晶体结构排列致密,在高温下能够保持稳定,从而使得水泥石能够保持良好的力学性能,进而有利于保护套管和改善水泥环层间封隔性能,延长稠油热采井的生产寿命.     

矿渣对铝酸盐水泥石性能影响的研究

铝酸盐水泥在混凝土工程中具备良好的耐高温性能,但因其在低温下具有温度敏感性,限制了其在固井工程中的应用.实验以铝酸盐水泥为主材进行矿物熟料优选复配,运用矿渣对铝酸盐水泥进行改良,并采用XRD、SEM和热分析等试验手段对作用机理进行分析.试验结果表明:矿渣可有效地改善铝酸盐水泥强度发展存在温度敏感区间的缺点,且能提高水泥石高温后的抗压强度以及长期耐温性能.低温下生成的水化钙铝黄长石(C2ASH8)可有效提高铝酸盐水泥石的强度发展,高温生成的C3AS2 H2和C3ASH4结晶度高,AlO(OH)填充在晶体的空隙当中,使得水泥水化产物结构紧密,水泥石力学性能长期稳定、耐温性能良好.     

铝酸盐水泥在高温和CO2气氛的水化机理研究

采用力学性能测试、X射线衍射分析、扫描电镜分析、X射线能谱分析、X射线荧光分析等现代材料分析测试方法,探索铝酸盐水泥石在高温及CO2气氛下的强度性能、物相组成、微观形貌等。结果表明：矿渣和铝酸盐水泥相互作用,影响水化过程,提高铝酸盐水泥的后期强度。铝酸盐水泥在高温及CO2气体气氛环境下养护后,强度在400 ℃以下养护不断发展,在400 ℃到达最大值,最大强度为36.39 MPa,其水泥石外层含有C2AS、C12A7等耐高温且结构致密的晶体,并且不被CO2气体腐蚀。相比于硅酸盐加砂水泥浆,铝酸盐加高温稳定剂水泥浆体更耐高温和CO2气体腐蚀。     

矿渣对固井用硫铝酸盐水泥石性能影响研究

目前,固井基本上是选用G级油井水泥,但随着油气田开采难度和井下情况的复杂化程度增加,固井难度不断加大,常规的油井水泥已不能完全满足工程需要,而具有特殊优异性能的特种水泥在固井工程中的应用研究将成为重点,并具有广阔的应用前景.因而为了探索硫铝酸盐水泥用作固井水泥石的可能性,本文选用矿渣A和矿渣C做为硫铝酸盐水泥的外掺料,针对硫铝酸盐水泥石后期强度倒缩的问题,对硫铝酸盐水泥进行改性.主要研究了矿渣的加量对硫铝酸盐水泥力学性能的影响.宏观上通过考察不同外掺料加量对硫铝酸盐水泥石抗压强度的影响,并通过X射线衍射,对矿渣改性硫铝酸盐水泥组分进行分析;采用岩心孔隙联测仪分析水泥浆水化后孔结构.微观上用扫描电镜对改性前后水泥石的微观形貌对比分析,从而得出宏观上抗压强度提高的原因.     

硫铝酸盐水泥的膨胀性能对固井一界面胶结强度的影响

硫铝酸盐水泥是一种具有微膨胀特性的新型固井材料,同时具有抗渗性好、耐久性持久、强度高等优点。为深入了解硫铝酸盐水泥的膨胀性能对其固井一界面胶结强度的影响,本文利用XRD分析硫铝酸盐水泥的水化进程及水化产物;通过三轴岩石力学测试系统,测定硫铝酸盐水泥石的膨胀特性以及一界面的力学性能;采用扫描电子显微镜观察硫铝酸盐水泥石一界面的微观形貌。分析结果表明:硫铝酸盐水泥的微膨胀特性可通过化学预应力的产生提高固井一界面的胶结强度,当龄期为1 d、3 d、7 d时,其一界面胶结强度比G级水泥浆分别提高了24.3%、20.1%和25.3%。微观机理表明套管表面分布着大量的铝元素和钙元素,形成结构较为密实的界面,有利于固井质量的提高。     

硫铝酸盐水泥的膨胀性能对固井一界面胶结强度的影响#br#

硫铝酸盐水泥是一种具有微膨胀特性的新型固井材料，同时具有抗渗性好、耐久性持久、强度高等优点。为深入了解硫铝酸盐水泥的膨胀性能对其固井一界面胶结强度的影响，本文利用XRD分析硫铝酸盐水泥的水化进程及水化产物；通过三轴岩石力学测试系统，测定硫铝酸盐水泥石的膨胀特性以及一界面的力学性能；采用扫描电子显微镜观察硫铝酸盐水泥石一界面的微观形貌。分析结果表明：硫铝酸盐水泥的微膨胀特性可通过化学预应力的产生提高固井一界面的胶结强度，当龄期为1d、3d、7d时，其一界面胶结强度比G级水泥浆分别提高了24.3%、20.1%和25.3%。微观机理表明套管表面分布着大量的铝元素和钙元素，形成结构较为密实的界面，有利于固井质量的提高。     

蒸汽养护条件下复合水泥胶凝材料的优化匹配

利用XRD、SEM、TG/DSC、MIP等测试方法,对常压高温蒸汽养护下矿渣和粉煤灰等不同组成的复合胶凝材料物理性能及水化特性差异进行研究.结果表明,85℃常压蒸养条件下水泥水化产物与标准养护下基本相同,但水化产物数量有大幅提高,且有少量C9S6H18和钙矾石(AFt)稳定存在.辅助胶凝材料的适宜匹配,使水泥石结构较致密,蒸养强度较高.少量硅灰的掺加,有利于优化水泥石结构,促进蒸养条件下水泥石强度发展.     

稻草纤维对硫铝酸盐水泥水化特性的影响

通过对凝结时间、电阻率和强度的测定,研究了稻草纤维对硫铝酸盐水泥水化特性和力学性能的影响。结果表明,(1)稻草纤维浸提液延长了硫铝酸盐水泥的凝结时间,但会降低硫铝酸盐水泥的强度,且随着浸提液浓度的增加,强度越低;对硫铝酸盐水泥水化产物的种类无影响。(2)用冷水、热水和氢氧化钠预处理稻草纤维,可降低稻草纤维对硫铝酸盐水泥水化的延缓作用和强度的不利影响。     

铝酸盐水泥对硅溶胶结合刚玉质浇注料结构与性能的影响

结合铝酸盐水泥与硅溶胶各自的优势来改善浇注料的力学性能是一种既廉价又简便的优化策略。以棕刚玉、致密刚玉等为主要原料，硅溶胶和铝酸盐水泥为结合剂，制备了刚玉质浇注料，研究了铝酸盐水泥加入量(加入质量分数分别为0、1%、2%、3%和4%)对硅溶胶结合刚玉质浇注料的影响。结果表明，铝酸盐水泥水化促进了硅溶胶的凝聚缩合反应，同时形成Si—O—Ca、Si—O—Al化学键，加快形成稳定的三维网络结构。随着铝酸盐水泥加入量的增加，试样经110℃养护后的常温强度增大，经1 100、1 400℃热处理后的常温强度先升高后降低，经1 400℃热处理后的高温抗折强度迅速下降，热震后的常温抗折强度先升高后小幅下降，强度保持率则逐渐增加。添加1%(w)铝酸盐水泥的硅溶胶结合浇注料试样的综合性能最佳。     

用磷石膏制备贝利特-硫铝酸盐水泥

本文尝试用云南当地不同企业产生磷石膏替代天然石膏作为原料,烧制贝利特-硫铝酸盐水泥.研究结果表明:在烧成温度为1250℃,保温时间为150 min,外掺石膏量为12％的条件下,可以烧制得到初凝时间约30 min,终凝时间约60 min,28 d抗压强度在49 MPa左右的贝利特-硫铝酸盐水泥.用磷石膏烧制成的贝利特硫铝酸盐水泥与用普通石膏烧制的贝利特硫铝酸盐水泥性质几乎相同,甚至在强度发展上还要优于后者.用未经水洗处理磷石膏烧制水泥的凝结时间比用经水洗处理过磷石膏烧制的贝利特-硫铝酸盐水泥凝结时间都要短.     

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。