整体多层包扎式高压容器筒体与球形封头连接区应力状态有限元分析

建立了整体多层包扎式高压容器多层筒体与球形封头连接区有限元接触分析模型,得到了端部阶梯式连接结构的应力分布状况,并与相同尺寸非多层结构的应力分布进行了比较。结果表明,两种结构内外壁应力变化趋势相似,在连接区出现明显的应力集中,连接处轴向应力上升趋势大于周向应力,达到最大应力值后迅速衰减。     

多层包扎容器筒体预应力分析计算方法

应用内筒收缩外层膨胀的过盈理论建立液压多层包扎筒体预应力分析计算的数学模型,提出了一种新的液压多层包扎筒体预应力分析计算方法,用于液压包扎工艺过程的优化和应力预测。经实例分析计算,并将计算结果与生产制造容器的水压试验结果对比,筒体整体应力和变形均达到HG3129-1998标准和ASME压力容器建造规则(ULW-77,ULW-78)的生产制造要求。     

多层包扎式结构在大型中压容器上的运用

在大型中压容器上采用多层包扎式结构进行了尝试。认为多层包扎式结构的适用范围不应限于高压容器,而是也应适用于厚壁的中压容器。当中压容器的筒体厚度比较大时,制造企业可以从容器结构、材料采购、制造装备、焊接、无损检测等方面综合考虑,是否采用多层包扎式结构。另外,当容器的简体厚度比较大,且对与介质接触的壳体材质有特殊要求时,采用多层包扎式结构,内筒可用厚度较小的特殊材料或复合板,层板采用普通材料,能降低设备造价。     

高压氨分离器应力分析评定

基于ANSYS Workbench 16.0分析平台,计算了多层包扎式高压氨分离器的筒体应力,通过线处理法对应力进行均匀化和当量线性化处理,依据JB4732为标准进行应力分析与强度评定。分析结果表明:多层包扎式筒体在高压情况下受力状况良好,应力评定满足规定,这说明在给定工况下,该高压氨分离器强度符合要求,能够安全运行,为工程应力分析及应力评定提供参考。     

整体多层包扎尿素合成塔制造关键工序及其质量控制

对尿素合成塔筒体的各种结构及其特点进行分析,着重介绍不锈钢衬里整体多层包扎尿素合成塔制造关键工序及其质量控制要点。整体多层包扎尿素合成塔的制造实践表明,通过建立合理的制造过程质量保证体系,严格控制制造关键工序及其质量要求,能保证整体多层包扎尿素合成塔的制造质量和安全性能。     

多层包扎容器设计时内筒钢板负偏差C_(1i)及许用应力〔σ〕_i~t的讨论

文章通过对内筒外壁需经机加工结构多层包扎容器的设计,制造进行分析,提出当内筒设计图样厚度处于临界值时,许用应力应以工艺下料厚度范围来确定,并认为内筒钢板负偏差C_(1(?))=0。     

φ3200mm氨合成塔多层包扎筒体制造特点

论述了大型氨合成塔以铬钼钢为内筒的多层包扎筒体制造过程中的特点。     

压力容器中边缘应力和局部高应力叠加影响研究

对压力容器中开孔接管靠近筒体与封头连接处的结构模型，采用有限元应力分析法分析筒体与封头连接处边缘应力和接管与筒体相贯区局部高应力叠加影响规律，通过建立不同的模型（开孔率不同，开孔和筒体与封头连接处距离不同）进行对比。结果表明，两种应力会相互影响，且开孔率越大，相互影响越大。当开孔率达到0.52时，接管与筒体相贯区的一次局部薄膜应力受筒体与封头连接处边缘应力的影响会增大10.27%，封头过渡区的一次局部薄膜应力受接管与筒体相贯区高应力的影响会增大18.8%。     

大型氨合成塔压力外壳结构设计优化

从简体、封头、端盖、密封形式等方面详细论述了大型氨合成塔的压力外壳设计特点,着重介绍了无深环焊缝多层包扎筒体的结构特点,并指出无深环焊缝多层包扎式简体是以后氨合成塔外壳结构的发展方向。     

氨合成塔结构设计优化

从筒体、封头、端盖密封形式等方面详细论述了氨合成塔的结构设计特点;着重介绍了无深环焊缝多层包扎筒体的结构特点。     

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。