浅析硫回收管道风载荷应力计算中的工况组合

针对硫回收装置管道设计中需考虑风载荷的应力计算管系,介绍了CAESARII软件用于管道应力分析的计算过程,讨论了热力管道风载荷计算中工况组合的方式,给出了一种较为合理的计算风载荷对热力管道影响的工况组合方式,为硫回收装置管道设计提供了参考。     

变换装置中高温管道的应力分析及设计

简单介绍了管道应力分析的意义及变换装置管道的特点.为了保证变换装置中高温管道的设计安全,利用CAESAR Ⅱ软件对一氧化碳变换装置的部分管道进行应力计算和优化,使设备管口的受力符合标准规范的要求,确保装置安全平稳运行.对一氧化碳变换装置高温管道的设计思路进行了探讨,提出了降低设备管口受力的几种方法,为同类管道的设计提供了参考.     

往复式压缩机组管道振动分析与应力计算

总结了某乙二醇项目二氧化碳压缩机组高压缸出口管道的配管设计及应力分析,利用CASERⅡ,对该管道进行了静力分析和动力计算,通过合理设置支吊架,使管系的应力、位移以及与其相连设备的管口受力达到标准规范的要求,使管系的固有频率避开共振区域,保证了装置中设备及管道的安全稳定运行。     

化工设计中的管道应力分析

介绍了化工设计中管道应力分析的重要性、应力分类、哪些管道需要进行应力分析以及管道应力分析的主要内容，提出了改善管系受力状况的几种方法。     

非金属膨胀节在烟气脱硫脱硝装置中的应用

烟气脱硫脱硝装置一般是在原有催化裂化装置内新增上的改造项目,其管道设计中存在管径大、安装空间受限等设计难点,一般需采用补偿器解决管系的应力问题。分析了催化烟气脱硫脱硝管系的具体特点,介绍了非金属膨胀节的结构组成及特点,对金属膨胀节及非金属膨胀节在烟气管道上的应用进行了对比,并总结归纳了非金属膨胀节在催化烟气脱硫脱硝装置管系中的应用及优缺点。     

高压抽注凝汽式汽轮机主蒸汽管道的应力分析

介绍了大型合成氨尿素项目中高压抽注凝汽式汽轮机主蒸汽管道的特点,为了保证高温高压管道的安全稳定运行及此类汽轮机的顺利开车,采用CASER II应力分析软件,对此类汽轮机的高温高压管道的配管进行了应力分析和优化设计,通过合理设置支吊架以及增加管系柔性,使汽轮机管口受力、管系的应力及位移满足标准规范的要求,并对弹簧的选型进行了论述。     

管道应力分析

阐述了管道应力分析的任务和方法,介绍了如何建立压力管道布置三维立体模型,管道上的荷载及其组合工况,以及如何对管系进行分析计算。     

管道支吊架的设置及选用

通过对同一管系的3种支吊架设计方案的计算,比较了不同方案对管系的影响并分析了其中的原因。认为在管道应力分析过程中,合理设置支吊架．能改善管系中的应力分布和端点受力及力矩状况。     

加氢精制装置分馏塔顶油气线的管道设计

在加氢精制装置管道设计中,分馏塔顶油气管线是具有代表性的重要管道。文章从平面布置、管道设计、应力分析和支吊架设置等方面对分馏塔顶油气管线进行了分析比较。对分馏塔顶油气管线的管道设计优化和支吊架的合理设置,可以降低管道对设备嘴子的受力,提高该管系及设备的安全性。     

炼油装置中大型泵进出口管道的柔性设计

介绍炼油装置中影响泵进出口管系柔性的诸多因素。举例分析通过改变管系的空间几何形状及改变管道元件的直径和壁厚增加柔性的方法,满足泵进出口嘴子的受力要求。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。