油田污水MED-TVC联合处理系统的Aspen Plus模拟与分析

为实现油田污水的高效洁净处理,提出了多效蒸发(multiple effect desalination,MED)和蒸汽热力喷射器(thermal vapor compressor,TVC)联合处理系统。应用Aspen Plus工具建立了MED-TVC系统的工艺流程模型,并进行了模型验证。在此基础上,分析了TVC对MED工艺的优化效果,研究了工作蒸汽压力和TVC引射位置对系统热力性能的影响。研究结果表明:增加TVC装置及提高其工作蒸汽压力均能有效改善MED系统性能;优化TVC引射位置可以使系统造水比提高12%,冷凝水流量减少22.54%。     

单效热压缩蒸馏海水淡化热力过程数值模拟

建立了单效热压缩蒸馏海水淡化系统的热力学模型。分析了蒸发温度、压缩比和主动蒸汽压力等主要设计参数对系统造水比、单位造水换热面积和单位造水冷却水量的影响。结果表明,降低蒸发温度、减小压缩比和提高主动蒸汽压力将提高系统造水比,而单位产水换热面积将随蒸发温度和压缩比的减小而增加;提高蒸发温度和减小压缩比可以减小单位产水冷却水量;主动蒸汽压力对单位产水面积和冷却水量影响较小。研究成果将对系统优化设计提供有益的参考。     

10t/d船用板式蒸馏海水淡化装置性能测试与模拟计算

建立了一套船用板式蒸馏海水淡化装置试验测试平台,对10 t/d淡化装置进行了性能测试,在测试所采用的海水及热水流量下,热水温度由59℃升高至83.77℃,淡水产量由400 L/h提高至550 L/h,进一步提高热水温度,淡水产量提高趋于平缓,操作时热水温度不宜超过85℃;随热水流量的增大,淡水产量呈现先升高后降低趋势;海水入口温度升高造成冷凝器中传热温差降低,真空度降低,产水量下降;海水流量是制约海水淡化装置真空度的关键因素,作为真空喷射泵的驱动水,当海水流量低于一定值时,淡化机真空度急剧下降,几乎不能出水。对板式蒸馏海水淡化装置进行了理论模拟,模拟结果与试验测试数据吻合良好。     

低温多效海水淡化进料方式的比较与分析

物料水进料方式决定着低温多效海水淡化装置的布置方式,对制水的经济性具有重要影响.对顺流进料、逆流进料和平流进料等几种进料方式的对比与分析表明,顺流进料方式蒸发器结垢风险最小,但经济性较差;逆流进料有效地改善了制水经济性,但需要多台中间进料泵,增加了系统的复杂性与运行电耗;平流进料盐水逐级自流,流程简单,经济性好.研究还表明,TVC的采用可显著降低蒸汽耗量和凝汽器的必要换热面积,有利于降低设备投资费用,提高制水经济性.     

船用海水淡化装置的产水水质特性及经济性分析

船用海水淡化装置是远洋船泊的必备设备之一,对产水水质特性及经济性进行研究具有重要的意义。本文设计搭建了一套板式蒸馏造水机性能测试平台,对系统产水pH和电导率随真空度变化规律以及进料水盐度和真空度对产水溶解性固体总量（TDS）的影响进行了研究,同时建立淡水成本数学模型探讨真空度和进料水流量引起的淡水产量变化对造水成本的影响,并进一步分析了油价、水价和渔船航行距离对淡水成本的敏感性问题。结果表明：真空度一定的情况下,进料水盐度升高,系统产水的TDS增大;真空度变化对系统产水pH影响不大,而对系统产水电导率、TDS和淡化水成本影响较大,且随着真空度的升高呈减小趋势。进料水流量为150L/h时,系统产水率最优造水成本最低,造水成本差价对油价的敏感性最高并且造水成本始终低于渔船运输淡水成本。     

新型中空纤维空气隙式膜蒸馏用于海水淡化

利用自制的添加隔热管状隔网并呈螺旋缠绕结构编排的中空纤维膜组件进行了空气隙式膜蒸馏(AGMD)海水淡化过程性能研究, 实验以模拟标准海水(质量分数3.5%, 总溶解性固体含量35000 mg·L^-1)为热料液进水, 考察了热料液进水温度、热料液流量、冷凝液进水温度和冷凝液流量对膜通量、造水比和热效率的影响。结果表明, 随着热料液进水温度增加, 膜通量、造水比和热效率均增加;冷凝液进水温度增加, 膜通量下降而造水比和热效率增加;热料液流量增加, 膜通量上升而造水比和热效率明显下降;冷凝液进水流量对膜蒸馏过程性能影响较小。实验过程中产水TDS始终保持在3.0 mg·L^-1以下, 相应的离子去除率高于99.99%, 膜通量、造水比和热效率最高可分别达5.87 L·m^-2·h^-1、5.37和0.943。研究表明, 引入清洁能源取代传统电加热驱动热源将进一步突出膜蒸馏技术的实际应用潜力。     

低温多效海水淡化系统的模拟计算

根据系统物料平衡、盐平衡、能量平衡、传热方程、热力学关系式及海水物性参数计算公式,建立了低温多效蒸馏海水淡化系统蒸汽喷射压缩器、蒸发器、淡水闪蒸罐及浓水闪蒸罐的数学模型。运用牛顿迭代法,确定了系统工艺参数计算的源程序。结合某电厂已投产四效平流低温多效蒸馏海水淡化装置,进行模拟计算,得出了系统造水比、比传热面积、比冷却海水流量等性能参数,且模拟计算结果与现场操作数据误差小于10%。     

低温多效蒸发海水淡化系统热力分析

建立了喷射器低温多效蒸发海水淡化系统的数学模型,计算分析了各种温度损失随温度的变化,并研究了顶值盐水温度、蒸发器效数和动力蒸汽等参数对系统的造水比和生产单位质量淡水所需传热面积的影响。结果表明各种温度损失在末效蒸发器内显著增加;喷射器低温多效蒸发系统的热力特性明显优于多效蒸发系统;通过增加顶值盐水温度、蒸发器效数和动力蒸汽温度,可以实现系统的优化运行。     

低温多效蒸发海水淡化系统性能的实验研究

针对大型海水淡化工程设计关键技术,依托1 t·d-1低温多效蒸发海水淡化实验平台,考察了装置运行性能的稳定性,系统地研究了不同海水进料量及首效蒸汽温度对造水比、浓缩比和产品水质等关键参数的影响。结果表明:在实验条件范围内,随着首效蒸汽温度提高,海水的浓缩比先减小后增加,而首效温度对造水比的影响较小;在一定首效温度下,浓缩比随着海水进料量的增大而减小,而造水比随海水进料量的增大而增大。在实验范围内,产品水的固体总溶解浓度均低于5 ppm。小型海水淡化平台关键技术的实验研究为低温多效海水淡化系统在扩大化中的设计优化提供了参考和借鉴。     

吸收式热泵海水淡化系统性能与经济研究

提出了单效溴化锂吸收式热泵低温多效蒸发海水淡化系统,建立了系统数学模型。分析了不同溴化锂浓溶液浓度对系统的影响,并与不带吸收式热泵的低温多效蒸发海水淡化系统进行了性能与经济比较。计算结果表明:在本文的计算范围内,随LiBr浓溶液浓度的增加,发生器产生的饱和蒸汽温度降低,所需动力蒸汽量减少,造水比升高,海水淡化装置蒸发器总面积增加,综合效果是淡水成本增加。在相同条件下,与不带吸收式热泵的海水淡化系统相比,吸收式热泵海水淡化系统的淡水成本可节省16.5%。     

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。