NMC800切断机调整方法的应用

通过对天津石化公司20万t聚酯短丝装置NEUMAGNMC800卧式切断机的组成与结构特点的分析,介绍了切断机球体与铜压环的调整方法,并在生产过程的实际应用中验证了此调整方法的可行性。     

浅谈苯乙烯装置中废气压缩机的检修

本文主要介绍了废气压缩机检修的注意事项,对其中关键点转子定位,齿侧间隙,螺杆间隙比率的测量与调整方法,进行了分析。     

旋转机械转子安装检修专用桥规的优化设计——以工业汽轮机为例

水平剖分式旋转机械在检修、安装过程中,其转子主轴与机体下气缸的径向间隙精度对设备的安全稳定运行极其重要,传统测量工具及方法存在局限性。利用优化设计的专用桥规可通过调整支脚距离对不同轴径水平剖分式旋转机械的径向间隙进行测量,并满足精度要求。     

给水泵检修的间隙测量与调整

通过对给水泵检修中各部位间隙的测量与调整来消除故障,提高水泵的工作效率,延长给水泵的使用寿命.     

边缘传动磨机大小齿轮齿隙的选择及控制

边缘传动磨机大小齿轮的齿隙(尤其是齿侧间隙)是齿轮啮合的重要指标,必须正确选择并加以控制。边缘传动磨机大小齿轮齿隙的选择,新磨机安装,要采用控制齿侧间隙的方法,并同时测量齿顶间隙作为以后检修时的参考;调校及检修,要采用控制齿顶间隙的方法。     

垂直剖分离心式压缩机间隙测量工装创新设计

垂直剖分的离心式压缩机组是过程工业的心脏设备,已被石油化工企业的裂解、加氢、重整等装置广泛采用,其安全可靠性是整个过程装置最关键的环节。因此,垂直剖分型离心式压缩机检修、安装过程中转子与定子轴向、径向间隙测量、调整精度对确保设备的安全稳定运行极其重要,传统测量方法存在局限性。通过优化设计及选材、强度、刚度及稳定性校核,专用测量工装可同时实现转子与定子轴向、径向间隙测量、调整,满足精度要求。     

多级离心泵轴向测量与调整方法剖析

多级离心泵在化工生产装置中使用较普遍,其结构复杂,检修过程中需调整的间隙较多,调整不当可能导致设备损坏乃至装置停车等重大事故发生。结合中海石油化学股份有限公司2套甲醇装置7台多级离心泵的实际情况,对几种结构的多级离心泵的轴向测量及调整方法进行剖析和探讨,以期为相关技术人员开展设备维护与检修工作提供参考或借鉴。     

透平膨胀机故障预防与检修

介绍了透平膨胀机故障产生的几种原因、如何预防和解决方法,侧重说明了膨胀机检修步骤,包括检修前的准备工作,卡机的修复与间隙调整,总体装配及机器的维护保养等.     

调整环密封工艺的试验及应用

分析了调整环及园柱齿轮外壳的产品参数,对不同种类的密封胶进行了分析与选择;分析了厌氧密封胶的反应机理,进行了调整环密封工艺试验,探讨分析了厌氧胶的固化温度、固化时间、密封间隙、环境温度对胶性能的影响以及促进剂等技术参数对密封工艺的影响。     

推土机侧传动部分齿轮毂与链轮毂压装间隙超差问题的研究

通过实验研究了推土机侧传动齿轮毂与链轮毂在加工、压装过程中,不同的加工方式、选配方式和压装方式对总装压装间隙的影响.实验表明:在齿轮毂、链轮毂加工过程中必须严格控制齿顶、齿根的锥度,所用刀具应及时进行检查,防止过渡磨损;同时规定齿轮毂与链轮毂选配过程中的选配方式和选配方法;调整齿轮毂与链轮毂压装间隙值,保证推土机侧传动压装及密封要求.     

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.     

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。     

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.