积层线路板用紫外光固化油墨

介绍了积层线路板用紫外光固化油墨的组成和特点以及影响积层线路板紫外光固化油墨性能的各种因素,着重介绍了感光树脂、新型引发剂和高性能单体开发的研究进展。     

UV固化漆酚改性环氧丙烯酸酯喷印油墨的研制

为了解决天然生漆不能喷印和快干固化的问题,用生漆对环氧树脂进行改性,在此基础上合成了一种新型预聚物——漆酚环氧丙烯酸酯。以该预聚物作为主要成膜物质,制备了UV固化漆酚改性环氧丙烯酸酯喷印油墨。配制出色浆基墨后,采用正交实验法,以喷头通过性、黏度、固化时间为测试指标,优选出UV喷印油墨的最佳配方。最后通过粒径分析和性能评价验证了优选配方,制备的UV固化漆酚改性环氧丙烯酸酯喷印油墨综合性能优异。     

有关电子元件用环氧树脂配制若干问题的讨论及配方实例

消除或降低环氧树脂固化过程带来的内应力,提高固化后环氧树脂的阻燃、耐水和耐湿热老化等性能是电子元件用环氧树脂配制研究中面临的几个问题.本文讨论了解决这些问题的一些措施及其机理,示出两种环氧树脂绝缘材料配方实例及其工艺方框图.     

积层电路板制造用光敏预聚物的合成及应用研究

用丙烯酸对酚醛环氧树脂进行改性,以使其具有感光性。考察温度及催化剂用量对反应的影响,并介绍积层电路板制造用液态感光成像油墨的配方和制作工艺,分析以合成的光敏预聚物为主体配制的油墨的感光性。结果发现,合适的反应温度为90℃,反应5h,转化率达91.83%;以十六烷基三甲基溴化铵为催化剂,其质量分数以1.5%为宜;以自制的光敏预聚物配制的油墨,在曝光20s时,双键的转化率可达80%以上。     

双酚S环氧树脂的研究进展

介绍了在不同的条件下双酚S环氧树脂的合成方法及其反应机理。经双酚S改性后,环氧树脂较改性前其固化物相容性变好,玻璃化转变温度、抗冲击强度和热稳定性均有提高。双酚S环氧树脂可用于制备胶黏剂、涂料、绝缘材料、电器保护件及液晶材料等。从合成、性能及应用几方面阐述了双酚S环氧树脂的研究进展。     

加热和湿气双重固化聚氨酯胶的制备和性能研究

通过控制配方中NCO值,配合环氧树脂、改性胺助剂,制备了能在加热和湿气条件下双重固化的聚氨酯胶,并探讨了NCO值、环氧树脂用量、固化温度和时间、改性胺用量对聚氨酯胶性能的影响。研究结果表明:加热和湿气双重固化的密封胶,解决了普通聚氨酯胶在高温烘烤过程中固化起气泡的问题。     

环氧树脂的增柔和增韧

<正>一、前言 环氧树脂由于其优良的综合性能及其配方技术的多变性,在各个领域皆获得十分广泛的应用。然而,由于环氧树脂固有的脆性,弹性模量高,伸长率低,在大多数实际配方技术中需对环氧树脂进行增柔或增韧改性。这种改性的目的在于:对于绝缘材料用     

中温固化单组分环氧密封胶的研制

以双酚A环氧树脂、双氰胺、脉及改性材料为主要成分配制的胶粘剂可在中温迅速固化。用DSC法考察了固化体系的最佳配方，引入改性材料以改善胶粘剂的使用性能。     

废弃线路板粉末/环氧树脂再生复合材料的增韧改性研究

将废弃线路板回收处理过程中得到的非金属粉料添加到环氧树脂中,采用模压成型制备废弃线路板粉末/环氧树脂再生复合材料。将增韧剂QS-065N添加至再生复合材料中,改变增韧剂用量及固化工艺条件,研究其对再生复合材料性能的影响。结果表明:增韧剂QS-065N可显著提高废弃线路板粉末/环氧树脂再生复合材料的韧性,QS-065N用量控制在20份左右时,再生复合材料综合性能较好;而较好的固化条件为130℃预固化1 h,150℃后固化8 h。     

超细膨润土/环氧树脂复合材料的结构与热性能

采用TG-DTA、IR、SEM、马丁耐热和Daniel流动点测定等方法，研究了有机胺改性超细膨润土与环氧树脂的固化体系的结构及其性能。结果表明，有机胺改性膨润土与环氧树脂固化复合后，可形成由层问固化与层外固化相结合的结构，所得复合材料的耐热性能、分散性均有提高，其中活化有机膨润土／环氧树脂复合体系的分散效果和马丁耐热特性改善更加显著。     

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.     

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.     

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。