发酵液预处理过程的特性

本文对抗生素发酵下游提取过程中的预处理部分的工艺特性进行详细研究。以林可霉素为例考察对发酵液滤速和效价的各种影响因素。实验发现:林可霉素过滤滤液速度随过滤的pH值的不同而变,在pH值=2.8时有一最佳峰值;温度对林可霉素发酵液的也有一定的影响,过高或过低都会影响滤液的滤速,在一定范围内随着温度的升高而滤速加快,通过实验发现当温度在50～55℃时过滤速度最佳。在林可霉素滤液中可能存在着蛋白质的溶解平衡,在过酸过碱时蛋白质会变性沉淀,温度过高时也会造成蛋白质的沉淀。林可霉素在蛋白质沉淀等固形物上存在吸附平衡,从而会影响林可霉素的过滤收率。     

从大豆粕提取干酪素

大豆粕与氢氧化钠、水以１：０．０９：１０的比例混合，在５５℃下提取７ｈ，过滤，滤液用盐酸中和至ｐＨ＝４．５－５，过滤，滤饼经漂白，干燥、粉碎、过筛得干酪素，由率在２９％以上。     

发酵液预处理工艺特性

研究了抗生素发酵液提取过程中的预处理工艺特性 ,考察了各种因素对过滤速度和滤液效价的影响 ,并以螺旋霉素 (SPM )为例进行了详细研究 .实验发现 ,SPM过滤滤液效价随过滤 pH值的不同而变化 ,在 pH =5 5时有一最佳峰值 .同时 ,在溶液中存在蛋白质的溶解平衡 ,在过酸过碱时蛋白质会变性沉淀 .而SPM在蛋白质沉淀等固形物上存在吸附平衡 ,许多外加物质可以产生竞争吸附而影响过滤收率 .对以上实验结果用修正的Langmuir吸附理论提出合理的解释 ,建立了理论模型 ,并推导出了数学公式 .     

酵母细胞的絮凝

利用自制的含硼酸盐的复合絮凝剂Ｆ１絮凝假丝酵母Ｙ－１０，絮凝效果优于其它絮凝剂．考察了环境因素对絮凝的影响，确定最佳絮凝条件为ｐＨ＝８．１，温度２５℃，Ｆ１加入量１６．６ｇ／Ｌ．并对絮凝机理和絮凝动力学进行了探讨．     

菜籽蛋白萃取速率

以菜籽蛋白萃取过程为研究对象，推导出内扩散控制时，单颗粒菜籽粕及菜籽粕颗粒群的蛋白萃取速率模型。结果表明，在较高温度（４０～５０℃）或较高的ｐＨ值（ｐＨ＝１１．５～１２）下，颗粒群萃取模型与实验数据相当吻合，并求得５０℃，ｐＨ＝１１．５时，ＯＨ－在菜籽粕中的有效扩散系数Ｄｅ＝６．３８·１０－１１ｍ２／ｓ。本文还讨论了萃取温度以及ｐＨ值对萃取速率的影响。     

烟草中果胶的提取研究

本文是利用盐析方法提取烟叶和烟杆中果胶质的研究。实验中以正交设计了萃取ｐＨ值，萃取温度盐析时的ｐＨ值对提取产率的影响。得出：萃取ｐＨ值为１左右，温度为８５￣９５℃，而加铁盐沉淀的ｐＨ值在４左右时效果最好，在些条件下，本院烟草栽培实验基地所产新鲜未熟烟叶的产率６．６４％（干基）；烟杆达到１．３１％；而福建产中二复烤烟叶达到６．１４％，结果令人满意。     

糠醇树脂聚合工艺的研究

叙述了糠醇树脂的聚合方法。以糠醇为单体，硫酸为催化剂，摸索了不同温度、反应时间、催化剂用量、反应物配比对聚合反应的影响，找出最佳聚合条件为糠醇／水＝７／３～７．５／２．５，溶液ｐＨ值在１．６左右，反应温度为７０～７５℃，反应时间为４ｈ。特别对反应开始时的突然升温现象进行了讨论并找到了解决方法。最后对树脂进行了固化实验，测定了其强度等各项性能指标。     

新显色剂6-甲氧基苯并噻唑偶氮-8-羟基喹啉-5-磺酸的合成及其与镍的显色反应研究

７－［６－甲氧基－（２－苯并噻唑偶氮）］－８－羟基喹啉－５－磺酸是一种新合成的显色剂。该试剂在弱酸性（ｐＨ４．５）介质中,与镍形成紫红色络合物。络合物的λｍａｘ＝５８０ｎｍ,表观摩尔吸光系数ε＝６．０８×１０４Ｌｍｏｌ－１ｃｍ－１,线性范围Ｎｉ（Ⅱ）０～１０μｇ／１０ｍＬ。用拟定的方法测定了合金钢及铝合金中的镍,加入回收率为９７％～１０５％,方法的相对标准偏差小于１．５％。     

碱性脂肪酶提取工艺的研究

采用０．１ｍ＾２的不锈钢板框对发醇液进行过滤，在超滤过程中料液ｐＨ值应保持在７．５～８．０之间，湿度控制在１３℃以下。超滤前滤液加入０．０５％的苯甲酸钠作防腐剂，并加一定的明矾，提高过滤速度，最佳的操作条件下，酶的提取总收率在７０％以上，脂肪酶粉活力单位在４．０×１０＾４Ｕ／ｇ。     

pH值对硅溶胶凝胶化过程的影响

研究表明：硅溶胶的凝胶化过程发生在ｐＨ＝３．５～７．５之间。在不同的酸的作用下硅溶胶的稳定性是不同的，其等电点也不相同．在ｐＨ＝５．５～６．１之间     

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。