点沸溶剂法制备核桃壳木质素

核桃壳中的木质素能在热的高沸溶剂（HBS）及少量催化助剂中溶解而与纤维素分离。由于HBS易溶于水而木质素难溶于水，因而加水能将溶解在HBS中的木质素沉淀出来。沉淀物经洗涤、低温冷冻干燥可得到低灰分的木质素。HBS经热蒸发去水后可循环使用。工艺过程无废液排放。HBS法能使木质自然资源得以充分利用，节能又不污染环境。     

木质素衍生物对三种蛋白酶的吸附研究

对高沸醇木质素和酶解木质素进行化学改性,以增加木质素的亲水性,制得新型高聚物HBS木质素酚和木质素氨基酚衍生物,研究了木质素衍生物时木瓜蛋白酶、胰蛋白酶和胃蛋白酶3种蛋白酶的吸附特性.结果表明:这几种木质素衍生物都能吸附3种蛋白酶;胃蛋白酶被酶解木质素氨基酚和HBS木质素酚吸附时能依然保持较高的活性,其活性回收率达到70%以上;木瓜蛋白酶被酶解木质素氨基酚和HBS木质素酚吸附时活性回收率达到0%以上;胰蛋白酶经各种吸附剂吸附后的活性回收率较低.因此木质素及其衍生物有望成为生物酶的浓缩吸附剂或固定化的优良栽体.     

高沸醇木质素的衍生物在橡胶改性中的应用(二)

(续上期)2.2环氧化木质素和氯丁橡胶改性2.2.1环氧化木质素的红外谱图分析传统的环氧树脂是由双酚A与环氧氯丙烷在碱性条件下反应,双酚A具有酚羟基,环氧氯丙烷具有环氧基,在碱性条件下,二者可发生反复的开环-闭环反应,直至反应单体或碱的耗尽。由于HBS木质素具有丰富的酚羟基,并具有很高的反应活性,初步推测HBS木质素环氧化的可进行性。图3不同比例环氧化HBS木质素的红外光谱图1)HBS木质素与环氧氯丙烷比例为1:4;2)HBS木质素与环氧氯丙烷比例为1:3;3)HBS木质素与环氧氯丙烷比例为1:2;4)HBS木质素与环氧氯丙烷比例为1:1红外光谱图…     

木质素的研究进展和在橡胶工业中的应用

高沸醇(High Boiling Solvents,简写为HBS)木质素是用高沸醇溶剂法从植物原料中提取的木质素,具有纯度高、化学活性强等特点。本文介绍了高沸醇木质素的制备及其研究进展,并着重阐述了HBS木质素及其衍生物在橡胶工业中的应用情况。     

硫酸铝钾制备实验的改进研究

金属铝既能溶于强酸,也能直接溶于强碱,而在通常情况下,金属铝在稀硫酸中的溶解速度较慢,但本研究表明,在少量HgCl2"催化"作用下金属铝在稀硫酸中的溶解速度可得到很大程度的提高。     

高沸醇木质素改性丁腈橡胶

高沸醇(HBS)木质素是用高沸醇溶剂法从松木、稻草中提取的一种新型的环保材料。研究了HBS木质素羟甲基化改性后共沉物对NBR补强效果的影响。由产物的红外光谱可知，HBS木质素的羟甲基化是可以进行的。试验结果表明，添加HBS木质素能改善NBR的性能，尤其是拉断伸长率有明显的提高，还有良好的耐老化性能，明显优于炭黑。     

硫酸盐木质素的分级分离及性能比较

利用酸析法对造纸黑液中的木质素分级分离,得到3种不同的木质素。对得到的木质素进行傅里叶红外光谱(FTIR)、凝胶渗透色谱(GPC)、核磁共振波谱(⁽¹³⁾C NMR)以及元素含量测定,在溶解率、分子量分布及官能团和元素含量等方面进行比较。结果表明,木质素在DMF/水混合溶剂中溶解率可达到96%,DMF/水混合溶剂可作为材料制备过程中的液体反应介质。酸析分级分离制备的木质素的分散性逐渐降低,分散系数最小可达到1.57,分子量分布均一,适合在材料领域应用。     

聚乙烯醇简易快速溶解法

聚乙烯醇(PVA)是一种由聚乙酸乙烯酯经皂化而成的高分子化合物。因其皂化程度不同,产物可溶于水或仅能溶胀。可溶PVA的溶解所以比较困难,是由于溶解过程中先     

环氧化高沸醇木质素对CR性能的影响

以环氧氯丙烷为改性剂制备环氧化高沸醇木质素（HBS木质素），探讨环氧化HBS木质素对CR性能的影响。结果表明，加入环氧化HBS木质素（4份），CR硫化胶的拉断伸长率大幅度增大，拉伸强度提高，定伸应力减小，拉断永久变形增大；采用按HBS木质素／环氧氯丙烷质量比为1：3制得的环氧化HBS木质素，CR硫化胶的综合性能较好。     

硫酸盐木质素的分级分离及性能比较

利用酸析法对造纸黑液中的木质素分级分离,得到3种不同的木质素。对得到的木质素进行傅里叶红外光谱(FTIR)、凝胶渗透色谱(GPC)、核磁共振波谱(~(13)C NMR)以及元素含量测定,在溶解率、分子量分布及官能团和元素含量等方面进行比较。结果表明,木质素在DMF/水混合溶剂中溶解率可达到96%,DMF/水混合溶剂可作为材料制备过程中的液体反应介质。酸析分级分离制备的木质素的分散性逐渐降低,分散系数最小可达到1.57,分子量分布均一,适合在材料领域应用。     

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。     

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.     

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.