泡沫分离法分离纯化无患子皂苷的研究

采用泡沫分离法分离纯化无患子皂苷溶液,收集溢出分离柱的泡沫液,采用紫外分光光度计分别测定原液和泡沫液的皂苷含量,通过富集比、回收率以及纯度表征分离效果。结果表明:在进料浓度为 2.0 g/L、进料量为 150 mL、气速为 32 L/h、温度为 30 ℃、pH值为4.3条件下,富集比可达到2.153,收率与纯度分别达到 79.19 % 和 74.68 %。     

连续泡沫分离蛋白质

本文以空气-明胶水溶液体系为研究对象，较为详细地考察了通气量、进料流量、进料浓度、进料位置、泡沫高度、溶液pH值等因素对连续泡沫分离明胶过程中明胶富集度变化的影响．     

微藻细胞的连续泡沫分离法采收

为考察连续泡沫分离法采收微藻细胞的可行性 ,在一种斜臂泡沫分离装置上 ,以螺旋藻为模型藻种 ,较为详细地研究了载气流率、藻液进料流率、浓度、pH值、离子强度、乙醇浓度、进料位置、泡沫段与液相段高度之比等因素对泡载采收性能的影响。结果表明 :在载气流率、藻液进料流率或藻液浓度较低时采收性能良好 ;当 pH值为 11、离子强度为 1 3× 10 ⁴ μs·cm^-1、乙醇浓度为 3%(体积 )时泡载收率可达 2 5 %～ 45 %;采用泡沫相段进料有利于提高泡载采收性能。提出的连续泡载采收动力学模型与实验值拟合较好 .     

消泡剂共存体系中泡沫分离蛋白质

在以牛血清白蛋白(BSA)为目标蛋白、聚环氧丙烷环氧乙烷甘油醚(PGE)为消泡剂的模拟体系中,考察了表面活性剂种类(非离子型Tween-20和离子型SDBS)、浓度、溶液pH及操作参数(气体流量、初始液池高度)对BSA分离效率的影响. 结果表明,2种活性剂均能改善模拟体系的泡沫性能,使泡沫分离. 后者作用更强并能促进BSA的吸附,因DBS-通过静电作用与带相反电荷的BSA结合形成疏水性更强的BSA-DBS复合物. pH通过影响BSA的电荷分布而影响其与SDBS的结合,进而影响对BSA的吸附,初始BSA浓度0.1 g/L, PGE 4 mg/L, SDBS 50 mg/L, pH为3.4时,约66%蛋白质浓缩在泡沫液中,富集比为5.34. 增加气速或初始液池高度可得到较高收率,但富集比减小.     

含铜和含锌稀溶液的吸附泡沫分离技术的研究

运用自制的泡沫分离塔,以十二烷基硫酸钠为表面活性剂对泡沫吸附分离含铜及含锌溶液的操作参数进行了研究。考察了料液浓度、pH值、气体流量、表面活性剂浓度等因素对含铜和含锌溶液泡沫分离效果的影响。结果表明：最佳操作参数为pH值5．0,料液浓度0．125mmol／L,进料流速50mL/min,气体流量100mL/min,表面活性剂浓度0．25mmol／L。同时从理论上推算出泡沫吸附分离铜离子的最佳pH值范围为5．0左右。实验还通过改变孔板的孔径大小以改变气泡的尺寸,特别研究了泡沫尺寸对泡沫吸附分离的影响。     

泡沫分离法回收废水中的全氟辛酸铵的研究

本文研究了用泡沫分离法回收废水中的全氟辛酸铵，通过实验研究了气体流量、进料液流量、进料液浓度、泡沫层高度和清液层高度之比、进料液的pH值等因素对废水中全氟辛酸铵脱除率的影响，得到了最佳的操作条件，为工业设计提供了有用的参考价值。     

卧式加压溶气泡沫分离水溶液中低含量蛋白质

以大豆蛋白为目标蛋白,蛋白水溶液为模拟体系,采用卧式加压溶气泡沫分离装置考察了原料液流量、pH值、溶气水流量等因素对蛋白质脱除率的影响,并根据其分子结构特征从过程工程视角分析了以卧式泡沫分离装置由水中去除的优势.结果表明,最佳操作条件为:原料液浓度8mg/L,原料液流量50L/h,pH值4.5,溶气水流量275L/h,该条件下水中蛋白质的脱除率可达90.5%.     

纳滤和泡沫分离联合处理含全氟辛酸铵废水的研究

采用传统方法处理含低浓度全氟辛酸铵(APFO)的废水存在能耗大、工艺复杂、二次污染等问题.为此提出用纳滤膜和泡沫分离联合处理含低浓度全氟辛酸铵的废水.首先对废水进行泡沫分离研究,在较佳的操作条件得到泡沫分离塔顶与塔底浓度比为11.4,再结合作者先前的膜分离研究结果,确定联合处理的操作条件为进料浓度450 mg·L-1,气体流量35 L·h-1,液体流量5 L·h-1,泡沫层与鼓泡层高度比1.0,pH值5.对聚四氟乙烯生产过程中产生的全氟辛酸铵浓度为450 mg·L-1的废水进行纳滤膜和泡沫分离联合处理,结果得到浓度分别为3690 mg·L-1的浓液和37.5 mg·L-1的清液;相比单独使用纳滤法和泡沫法处理废水来说,纳滤与泡沫分离联合工艺流程减少了能耗,同时具有回收有用物质、处理过程环保、设备简单、易于工业放大等优点.     

Span-20和Tween-80对发酵液中Nisin泡沫分离的影响

研究了微量非离子表面活性剂Tween-80和Span-20对发酵液中乳链菌肽(Nisin)泡沫分离的影响. 结果表明,发酵液泡沫分离时泡沫层轴向气泡直径、连续通气过程的泡沫层高度、泡沫层平均持气量等均因添加活性剂而明显变化. 不同体系气泡大小为,含0.2 g/L Span-20发酵液>含0.5 g/L Span-20发酵液>发酵液>含0.2 g/L Tween-80发酵液>含0.5 g/L Tween-80发酵液;Tween-80的加入破坏了气泡表面的网状结构,因而泡沫层持气量较高;连续通气时,2种表面活性剂都会引起泡沫层高度降低,但Tween-80会增加泡沫层的稳定性. 当Tween-80浓度达0.5 g/L时,Nisin的收率大幅度提高,原因是分离过程中Nisin失活率减少.     

螺旋藻泡载分离法采收的实验室研究

在一种斜臂泡沫分离装置上，较为详细地研究了泡沫塔构造、起泡剂Tween 20浓度、载气流率、pH值和乙醇浓度等因素对螺旋藻泡载采收性能的影响. 结果表明，斜臂泡沫塔可明显改善藻细胞的泡载性能, 当Tween 20浓度为100 mg/L、载气流率为30 L/h及pH=11、乙醇浓度为1%(j)时，泡载采收过程的分离因子R和浓缩倍数a可分别达到5.04~6.52和2.74~4.31.     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008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、不饱和聚酯树脂、环氧树脂)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.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006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生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。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（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。