在用焦炭塔的裂纹深度测量研究

在用焦炭塔普遍带着裂纹缺陷运行。通过精确测量其裂纹深度,可以对裂纹的扩展情况进行有效的监控及处理,保障焦炭塔安全运行。文章根据在用焦炭塔的定期检验和安全评估工作实践,对裂纹深度测量进行了相关的研究。     

焦炭塔裙座环焊缝裂纹形成机理与防治研究

对焦炭塔裙座环焊缝裂纹破坏的表现形式和裂纹的形成机理进行了系统分析,提出了相应的防治措施,并经实际应用取得了良好效果,为在役焦炭塔的维护或改造以及新焦炭塔的设计提供了依据。     

延迟焦化装置焦炭塔的改进设计

将炼油行业传统焦炭塔的下裙座支撑改为上裙座支撑,在焦炭塔外壁增加一夹套,改变了焦炭塔的受力,避免了塔体下部鼓胀变形和焊缝冷裂纹的产生。大幅度提高了焦炭塔的使用寿命。     

焦炭塔裙座焊缝开裂原因分析及缺陷处理

对某焦炭塔的裙座与锥封头连接角焊缝在服役过程中产生裂纹的原因进行了分析和探讨,通过对裂纹缺陷的检验和裙座结构分析,制定了有效的裂纹缺陷处理方案,提出焦炭塔裙座与锥封头连接角焊缝的局部结构改进的建议。     

焦炭塔裙座环焊缝裂纹原因分析及改进措施

焦炭塔在使用过程中受到热应力和机械应力的联合作用,焦炭塔塔体与裙座的连接焊缝处极易产生裂纹,通过宏观检验、无损检测、壁厚检验、光谱分析及理化检验等手段,对裂纹的形成原因进行分析,得出裂纹主要是由于塔体与裙座的温差、相互的变形约束、频繁加热冷却引起的交变热应力及局部机械应力等原因联合造成的,并且提出了相应的解决措施。     

4#焦炭塔筒体鼓胀变形分析

焦炭塔从1990年建设投入运行至今,在运行过程中从塔底部锥段向上多层塔节发生了臌胀变形,并发现了大量表面裂纹,利用无损检测、金相分析等手段进行分析,确定该塔还可以在稳定操作条件下继续生产。     

焦炭塔复合板裂纹原因分析及修复工艺

介绍了某装置焦炭塔在施工安装阶段,检验复合板环焊缝时,在焊缝附近复合板内部发现存在裂纹的部位和形态,及其修复过程。     

应用蒙特卡罗法对焦炭塔疲劳寿命可靠性的分析

针焦炭塔的疲劳失效分析,以概率论为基础,结合确定性的疲劳断裂力学估算方法,推导了焦炭塔的疲劳裂纹扩展寿命的计算公式.考虑到主要评定参数初始裂纹尺寸、工况载荷、断裂韧性、机械强度和系数等的不确定性和随机性,应用蒙特卡罗模拟法对这些具有某种特定分布的随机变量进行了随机抽样计算,并利用数值积分法编制了计算机程序.求出在一定可靠度和置信度下的疲劳寿命,并与理论计算方法求得的疲劳寿命进行了比较.分析结果表明,蒙特卡罗模拟法真实地反映了评定参数客观存在的不确定性,克服了确定性评定方法的缺点,具有良好的工程指导意义.     

基于风险的检验技术(RBI)在焦炭塔上的应用

介绍了焦炭塔常见失效模式以及采用风险检验的过程及方法,指出使用RBI技术后可以得出焦炭塔的实际风险,根据风险再考虑损伤模式等因素有助于制定焦炭塔的合理检修方案。     

焦炭塔冷却过程中残余应力产生原因及数值分析

由于焦炭塔是在冷热循环的条件下工作的,所以在焦炭塔冷却的过程中产生的残余应力对塔体的变形也产生很大的影响,对此进行了理论上的解释说明和数值分析。由计算结果得知,导致焦炭塔腰鼓变形的主要因素是焦炭塔简体周向残余应力过大,产生较大的塑性变形。     

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。