软化水真空除氧设施

锅炉软化水的热力除氧方法虽然简单易行,但需耗用大量蒸气,而真空除氧法具有蒸气耗量少的优点。上海炼油厂最近建成一套150吨/时处理能力的软化水真空除氧/凝结水回收联合设施,水质符合锅炉给水标准。真空除氧是在减压下进行,除氧器中水温保持在器内压力下高于水的饱和温度0.5～1.0℃,使水表面处于沸腾状态,溶于水中的气体(包括氧气)被解吸出来,然后连同水蒸     

浅析锅炉给水泵的汔蚀与治理

工业锅炉给水泵一般都用单级或多级离心泵。为了防止锅炉内部氧腐蚀,国家劳动部门规定,2吨/h以上蒸汽锅炉给水要进行除氧处理。而目前锅炉水质的除氧,大都是热力除氧。水温104℃,在除氧罐里以饱和蒸汽压     

锅炉的腐蚀与结垢(连载)

三、防止锅炉水腐蚀的方法防止锅炉水腐蚀的方法有:①进行水处理(软化、脱氧、加入添加剂等);②加强锅炉的管理。如:投产前进行清洗、钝化,运行时合理操作,停炉时很好保护。因此,防止锅炉水腐蚀应采取全面腐蚀控制方法。下面简单介绍除氧、除二氧化碳、防止碱脆几种方法。水质处理已成为一门专门技术,故不予介绍了。 1.脱氧:氧是中性水溶液中腐蚀的一个去极化剂,因此为了减少锅炉的腐蚀,应该脱去     

锅炉给水除氧技术的应用探讨

锅炉给水除氧是保证锅炉安全经济运行的关键。传统的物理除氧及化学除氧方法具有较高的成本以及复杂过程,且化学除氧过程中会用到化学药剂,可能对锅炉水造成污染。通过电化学除氧方法能够较好地解决这些问题,提高锅炉给水除氧的效率和经济性。对锅炉给水电化学除氧技术的应用进行了讨论。     

EWPT水处理技术在锅炉水系统中的应用

兰州石化公司化肥厂C锅炉装置锅炉水处理系统原采用氨水调节给水pH、联胺除氧、磷酸盐调节稳定炉水水质的水处理方法,存在人工操作状况下加药量不好控制、水质不稳定、系统腐蚀和结垢、锅炉排污量大等问题。后通过采用EWPT水处理技术,有效稳定了给水pH,进一步除去了给水中残余的溶解氧,     

工业锅炉给水除氧方式探讨

在锅炉给水中,溶有多种气体,其中对热力设备危害最大的是溶解氧.在热力系统中,由于水汽温度都较高,使得金属受热面氧腐蚀的速度进一步加快,威胁锅炉运行.因此,国家技术监督局对各类锅炉水质有对应的法规标准进行规范,在设计中选择适合工程特点除氧方式是设计者经常面对的难题.对常用的热力除氧、真空除氧、化学除氧、解吸除氧等技术进行了分析比较,与设计同行探讨.     

煤气厂锅炉给水处理

根据锅炉给水的特点,介绍煤气厂给水需要进行的几个过程：水的净化、水的软化、水的除盐和水的除氧,使水达到锅炉用水质量标准,作为锅炉用水供给锅炉,保证锅炉的安全、经济运行。     

一种新型锅炉水催化除氧设备

在分析国内锅炉水除氧工艺与设备的基础上,采用二次催化工艺,研制出一种新型锅炉水催化除氧设备。该设备以电解钴作为一次催化剂,以多孔稀土作为吸附剂,富集钴离子作为二次催化剂,现场试验表明,经二次催化后,化学除氧反应速度大大提高,还原剂仅需稍大于理论用量,即可使出水残余氧的质量浓度小于0.05mg/L,并可使除氧反应的温度降为常温。     

油田注汽锅炉用水除氧剂的研究

作者从静态方面测量一些变量对亚硫酸钠除氧效果的影响,来确定适用于油田注汽锅炉除氧的最佳条件和除氧剂,若单独用硫酸钠作除氧剂,则因水中亚硫酸钠的残余量高,产生严重的酸腐蚀,而不适用作油田注汽锅炉除氧剂,根据催化机理,在弱碱条件下加入二价镍离子和二价钴离子能提高水中亚硫酸的反应效率,降低水中亚硫酸钠的残余量,对亚硫酸钠的除氧效果具有明显催化作用,若按处理后水样中亚硫酸钠的残余量和吨水处理费用越少越好衡量标准,硫酸钴催化亚硫酸钠除氧剂是最适合用作油田注汽锅炉用水除氧的除氧剂.     

基于PLC的煤粉工业锅炉除氧系统研究与改造

为了解决神东哈拉沟煤矿、寸二煤矿、补连塔煤矿工业煤粉锅炉系统除氧器存在的除氧效果不稳定问题,利用PLC(Programmable Logic Controller,可编程逻辑控制器)来控制除氧系统的电气设备,实现全自动控制,提升除氧器性能,为锅炉系统稳定高效运行打下良好基础。结果表明,改造完成后,除氧水箱的水温始终维持在102℃,液位保持在水箱液位的4/5处,从而为锅炉系统提供稳定且达标的水质,减少锅炉设备损耗,提高锅炉热效率,实现节能减排。     

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.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

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。