粗颗粒在负压差漏斗-立管系统悬料区特性

负压差漏斗－立管系统是化工设备中常见的系统。在本文中主要研究了Ｇｅｌｄａｒｔ－Ｄ类物产在此系统中悬料区的特征。实验结果表明：立管底部孔口大小对于悬料萄下限有影响,而对上限无影响;相反,漏斗中的物料高度、漏半的锥度、立管长度和立管直径对悬料区的操作有很大的影响。本文根据实验结果给出了悬料区上、下限的条件。     

负压差移动床立管料斗中散体粒流动特征

本文给出利用料斗中体均压力梯度与立管压力梯度的关系判别压力控制区，气泡控制区、气栓控制区和悬料区的方法，在气栓控制区，料斗中体均压力梯度有如下关系「（－ｄｐ／ｄｚ）ｖ」ｈｐｌｕｇ＝０．２４１ρｂｍｆｇ而且，菜体颗粒平均质量流率可以用Ｂｅｖｅｒｌｏｏ方程来预测，在此基础上，讨论上料斗中体均压力梯度对散体颗粒通过孔口平均质量流率的影响，并给出预测平均质量流率的关联式，给出一种新的立管约束条件，即料斗阀     

负压差移动床上管料斗中散体颗粒流动特征──Ⅱ散体颗粒平均质量流率研究

本文给出利用料斗中体均压力梯度与立管压力梯度的关系判别压力控制区、气泡控制区、气栓控制区和悬料区的方法。在气栓控制区，料斗中体均压力梯度有如下关系[（一dP／dz）]hplug=0．241pbmfg而且，散体颗粒平均质量流率可以用Beverloo方程来预测。在此基础上，讨论了料斗中体均压力梯度对散体颗粒通过孔口平均质量流率的影响，并给出预测平均质量流率的关联式。给出一种新的立管约束条件，即料斗阀的设计方法和操作范围。     

负压差移动床立管料斗中散体颗粒流动特征Ⅰ流区研究

通过对负压差移动床立管料斗中的散体颗粒流动状态的观察，结合散体颗粒通过料斗的平均质量流率和压力波动信号分析，将散体颗粒流动分成压力控制区、气泡控制区、气栓控制区以及悬料区，并分析了孔口直径、料斗的半锥角和物料特性对流区的影响，给出流区划分界限。     

基于导管架平台的海洋立管悬跨设计

常见的海管悬跨设计研究主要集中在处于海床的海管悬跨分析,本文介绍了基于导管架平台的海洋立管悬跨设计方法,从立管卡子的布置要求和立管的最大允许悬跨长度两个方面给出了处于垂直状态的立管悬跨设计进行了分析,并以实际立管数据为基础对立管最大允许悬跨长度设计方法进行了示例计算。     

负压差移动床立管料斗中散体颗粒流动特征：Ⅰ流区研究

通过对负压差移动床立管料斗中的散体颗粒流动状态的观察，结合散体颗粒通过料斗的平均质量流率和压力波动信号分析，将散体颗粒流动分成压力控制区，气泡控制区，气栓控制区以及悬料区，并分析了孔口直径，料斗的半锥角和物料特性对流区的影响，给出流区划分界限。     

旋风分离器料腿漏风对压降影响的实验分析

以直径300 mm的旋风分离器为实验对象,考察了在不同入口速度下料腿漏风量对旋风分离器压降的影响,并以此为基础,分析了某现场催化裂化装置旋风分离器压降出现的不稳定波动现象。实验结果表明,旋风分离器下部料腿是一个负压差立管,外部的压力大于料腿内的压力,易产生漏风,从而导致旋风分离器的压降降低。旋风分离器的压降随漏风量增大而降低,入口速度越低漏风量影响的作用就越明显。该旋风分离器的压降波动是由于不稳定的翼阀排料产生的漏风变化造成的。     

颗粒塞阀及其操作特性的研究

通过对粗聚丙烯和瓷球两种Geldart-D类颗粒漏斗-立管系统实验研究,发现在悬料操作区域内,漏斗-立管系统具有较高的抗压能力。因此,把在悬料条件下具有抗压特征的漏斗-立管系统(无机械转动部件阀门)称之为“颗粒塞阀”。颗粒塞阀的抗压下限可由下式-dp/dl=200(1-εmf)^2μgUmf/εmf^3(φsdp)^2(D0/D1)^2 7.0(1-εmf)ρg（Umf)^2/φsdp(D0/D1)^4沿立管高度积分求得;而抗压上限是由Ergun公式沿立管高度积分求得,但计算所用的气速是指此系统的漏斗中颗粒的有效重量等于气固之间作用的曳力时所对应的立管中气速。并指出了此阀可用于把颗粒从低压容器输送到高压容器的场合。     

深水钢悬链立管J型铺设安装强度分析

钢悬链立管是深水开发的首选立管形式,J型铺设是深水和超深水立管安装的常用安装方法。本文以工作水深3000米的钢悬链立管为研究对象,进行J型铺设,使用orcaflex软件进行建模和动态分析,计算出立管整个安装过程中各个阶段的最大应力和张力,与相应规范校核,并分析其产生原因,得出结论该类型立管可以铺设,找到铺管船张紧器的张紧能力,选取合适的铺管船,为立管实际安装提供理论参考。     

浅谈钢悬链立管环焊缝无损检验方法的适用性

钢悬链立管是深水油气田开发半潜平台中一个重要的组成部分.陵水17-2气田群开发工程项目中包含了6条钢悬链立管.钢悬链立管受到循环载荷作用,因此钢悬链立管的焊缝质量要求十分严格,必须对焊缝内缺陷的位置和尺寸进行准确判断,包括深度、高度和长度.并结合钢悬链立管铺设的特点,对常用的无损检验方法原理及优缺点进行了对比,结果显示...     

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.     

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。     

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.     

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.     

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.     

基于ATRP法制备的触角状亲水性羟胺树脂的吸硼性能的研究

以大分子引发剂氯乙酰化聚苯乙烯微球(PS-acyl-Cl)经原子转移自由基聚合(ATRP)法引发丙烯酰胺(AM)和甲基丙烯酸缩水甘油酯(GMA)单体的共聚接枝,制得一种触角状亲水性环氧载体(PS-acyl-g-P(AM-co-GMA)),再经二乙醇胺(DEA)的环氧基开环胺化反应,得到一种含多个-NCH2CH2OH螯合配基的多齿-五元螯合环的触角状亲水性羟胺树脂(PS-acyl-g-P(AM-co-GMA)-DEA)。将此树脂用于硼吸附研究,结果表明,PS-acyl-g-P(AM-co-GMA)-DEA树脂对硼的吸附满足Langmuir方程,为单分子层吸附;饱和吸附量约为37.7 mg·g-1,且树脂5 min即可达到吸附平衡,与其它已报道的吸硼树脂相比,该树脂具有更高的吸附量和吸硼速率。吸附动力学研究表明,树脂吸附硼的过程主要由颗粒扩散过程控制。重复使用5次后该树脂的吸附量基本不变,解吸率均在90%以上,重复使用性能良好。