血液透析过滤传质动力学的简化模型

血液透析（HD）、血液过滤（HF）和血液透析过滤（HDF）是目前临床上治疗慢性 肾功能衰竭最常用的 3种疗法。以往人们对 HD的传质动力学作了较多的研究l’，‘］，而对 HF、HDF的研究则较少。虽然PopoviCh等门、Jaffrln等M相继提出了描述HF、HDF 传质动力学的一、二维模型，但文献囚的模型仅适用J” HD和 HDF；而巳，其解的形式     

超滤对血液透析传质性能的影响

本文对空心纤维型血液透析器中的传质过程进行了研究,提出了伴有超滤的血液透析过程中血液一侧传质的数学模型,并用分离变量法获得了该模型的分析解.实验数据表明,用该模型能较好地描述具有超滤的血液透析过程的传质机理.     

用正交配置法求解血液透析超滤的传质动力学模型

提出了血液透析、血液超滤和血液透析超滤过程传质的通用模型,并利用正交配置技术分析了影响传质速率的各种因素.结果表明,采用正交配置法进行上述传质过程的模拟时,简单的三点配置即与解析解的结果接近.采用正交配置法比有限差分法简单、快速和准确.     

不同过滤方式下过滤速率衰减模型研究

对真空死端过滤、气压死端过滤、轴向流十字流过滤、旋转流十字流过滤等不同过滤方式下的过滤速率衰减行为进行了系统的研究,建立了相应的过滤速率衰减模型、以及相应模型系数与悬池液浓度、操作压力、雷诺数和欧拉数等影响因素的关系式。结果表明,死端过滤速率衰减模型中过滤速率与时间呈幂函数关系、而十字流过滤速率衰减模型中过滤速率与时间则呈一次函数关系,死端过滤时悬浮液浓度和气压过滤压力对其过滤速率衰减模型系数的影响均呈三次函数关系,在十字流过滤时悬浮液浓度、操作压力以及雷诺数对模型系数ｂ的影响均呈线性关系,轴向流十字流过滤速率衰减模型系数ｂ与欧拉数呈反比,而旋转流十字流过滤时则模型系数ａ与欧拉数呈反比关系。十字流过滤中,旋转流方式同轴向流方式相比,过滤速率衰减趋势较陡,但其初始通量高,在较长时间内都能以高于轴向流过滤通量的状态运行。     

过滤洗涤特性曲线的一种函数拟合

本文分析了过滤洗涤的传质机制。在此基础上,重点讨论了洗涤传质效率β在整个过程中的变化,并以相近的函数进行了拟合,导出过滤洗涤过程中洗出液浓度随时间变化的关系式。所得理论曲线与实践总结出的过滤洗涤特性曲线吻合较好,反映了过滤洗涤过程变化的主要特征。     

超声耦合下的动态过滤流场行为研究

根据实际生产中的物料提纯工艺要求,完成了一种新型多功能设备的研发设计,该设备同时具备混合萃取、再化浆洗涤和过滤分离3种操作功能,并引入了超声力场与动态搅拌离心耦合,以强化其在前3种功能操作中的传质与分离效果。为了进一步验证超声作用的影响,运用流体力学计算软件建立了搅拌洗涤过滤釜的三维计算模型,分别从搅拌混合过程和动态过滤过程2个方向进行数值模拟计算,研究了在以上2个过程中的操作条件对混合或过滤规律的影响。对实验研究和实际生产过程提供了指导作用。     

金属丝网过滤技术在液氦纯化中的研究与应用

介绍了金属丝网过滤技术的结构特点及作用机制,重点阐述了压降特性及捕集能力。利用金属丝网的微孔特性,论证了采用该技术进行低温液体纯化的合理性及优越性。并以液氦纯化为例,在总结国内外技术的基础上提出了金属丝网过滤及再生方案,并比较了现有的过滤模型,指出应用于液氦纯化时需要改进随机函数并考虑沉积的不稳定性的影响。     

过滤沉降操作过程的分析

对于水平型式的过滤机,一般情况下,其操作过程应同时考虑过滤和沉降两种作用,但是,经典Ruth过滤公式没有考虑到沉降作用对滤饼堆积所产生的影响。本文同时考虑过滤和沉降两种作用对滤饼过滤所产生的影响后,推导出了恒压过滤沉降方程式,并指出,Bockstal等人在分析过滤沉降问题时所存在的不合理之处,以及求解微分方程和对其进行化简过程中所存在的问题。文中还对过滤沉降操作过程进行了比较详细的分析和讨论,同时指出,仅当过滤沉降参数f≤0.08[1/m]时,固体颗粒沉降对滤饼过滤的影响方能怎略不计,此时,Ruth公式才可适用。     

过滤优化中人工神经网络的应用

在饮用水的处理中,采用颗粒式过滤介质过滤是个很重要的过程。过程用以确保充分去除携带病原体(如:贾第虫和隐孢子虫,Giardia and Cryptosporidium)颗粒。通常,通过检测过滤后的水浊度来反映过滤性能的优劣。不过,颗粒数对于过滤操作中细微的变化极其敏感,所以颗粒数可以进一步反映过滤效率。埃尔金区水处理厂(WTP)应用人工神经网络(ANN)通过考察过滤后的水中颗粒数,对过滤进行优化。成功地开发了过程模型预测过滤后颗粒数。开发了两套逆过程模型,用来预测颗粒数达到要求时,凝聚剂的最佳用量。对模型进行检验显示,实测值和预测值之间具有较高的相关性。然后将这些ANNs集成到一个优化应用中,通过这个优化应用,模型和在线监控和数据采集系统(SCADA)之间可以进行实时数据传输。     

微孔薄复合过滤介质及其过滤行为

针对常规机织过滤介质的缺点，本文研究并开发了一种新型微孔薄膜复合过滤介质，并考查了该过滤介质力学性能及过滤特性。研究结果表明，这种过滤介质具有良好的力学稳定性和化学和惰性，因体颗粒截留率是堵塞程度低，使用寿命长，滤液浊度低，完全可用于气压过滤中。     

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.     

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。     

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.     

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.