远程等离子体处理对聚四氟乙烯表面的功能化改性

采用远程氩等离子体对聚四氟乙烯(PTFE)膜进行了表面改性研究,通过接触角测定仪、扫描电子显微镜(SEM)和X射线光电子能谱仪(XPS)等手段,分析研究了改性后材料表面结构、性能的变化。结果表明:PTFE表面经远程氩等离子体处理后,表面微观形态和表面化学成分均发生了变化,且处理效果优于常规氩等离子体。远程氩等离子体可以在一定程度上抑制电子、离子的刻蚀作用,强化自由基反应,使材料表面获得更好的改性效果。经远程氩等离子体短时间(100s)处理后,PTFE表面的F/C比例从1.97降至1.44,O/C比例从0.015增至0.086;表面的水接触角从108°减小到53°;表面自由能从22.4×10-5N·cm-1增加至52.3×10-5N·cm-1。     

聚四氟乙烯表面等离子体修饰氨基及XPS分析

采用氢气/氮气等离子体对聚四氟乙烯(PTFE)片基表面进行了处理,通过正交实验和接触角的测定优化等离子处理条件;XPS光谱分析了改性后的PTFE的表面官能团的组成。结果表明：PTFE片基经氢气/氮气等离子体处理后,表面的C-F键发生了断裂,形成了大量活性氨基,其表面具有很好的生物活性和亲和性。     

水平固体表面上液层极限高度的估算

建立了液体表面张力γ_l、液体与固体(基板)间的接触角θ,同该固体的水平表面上液层最小高度h_(min)之间的关系式。对水在PTFE、PP、PE、PS_t 和PET 板(片)上的h_(min)进行了计算,计算结果与实验测定值表现出良好的一致性。与液体在水平固体表面上最大液层高度h_(max)同γ_l、θ之间的关系式相结合,可以推测成膜溶液在水平固体基板表面上形成固体致密膜的极限厚度。     

固液平衡研究—利用拓扑指标关联活度系数

本文利用表征分子特性的拓扑指标3ξ,关联二元溶液活度系数。得出: 1.v_i=l_n (θ_i)/(sum from j=1 to 2(1/j)θ_j x_j)+1-(θ_i)/(sum from j=1 to 2(1/j)θ_j x_j)+K[((θ_x)≠i)/(sum from j=1 to 2(1/j)θ_j x_j)]~2 ·θ_i/RT K为通过实验确定的参数。利用上式,计算了27种二元低共熔物系的固液平衡(t-x)关系,得到令人满意的结果。     

等离子体紫外接枝对聚四氟乙烯表面改性的研究

聚四氟乙烯(PTFE)膜经Ar低温等离子体预处理,无光引发剂紫外光照接枝甲基丙烯酸缩水甘油酯(GMA)。通过接触角测量,考察了等离子体不同处理时间、接枝GMA的体积分数、接枝时间对PTFE膜亲水性的影响。以X光电子能谱(XPS)为手段,探讨并比较了PTFE膜表面改性前后的表面组成。结果表明,PTFE膜用Ar等离子体预处理,再进行紫外光照接枝GMA,其表面对水的接触角由110°可以降低到65°左右,亲水性得到大幅度改善。     

两种γ-Fe_2O_3磁粉的表面润湿性

按照毛细渗透速度法原理,选用 Washburn 方程 h~2=(γ■c■cosθ/2η)·t,可以研究粉末液体体系的透渗速度与接触角,进而可获得粘附功、浸湿功和铺展系数等参数。据此,我们对国产γ-Fe_2O_3磁粉和美国大力神γ-Fe_2O_3磁粉与一系列液体间的关系,分别进行了实验测定比较。结果表明,所有系统其 h~2与 t 均呈良好的线性关系(线性相关系数均大于0.998),同时显示出两种磁粉在性能上的一些差异。这为改进我们的磁粉生产工艺提供了很重要的信息。     

图解法求算液体表面张力

大多数液体的表面张力一般可用下式(适用的温度范围通常在15—20℃间)进行计算:δ_2=δ_1〔(Tc-T_2)/(T_c-T_1)〕~(1·2)式中δ_1指在温度 T_1时的表面张力δ_2指在温度 T_2时的表面张力Tc 指某液体的临界温度     

第三讲 分界面与重度的测量

在容器中某一范围H内充满两种互不溶混的液体,两种液体的重度为γ_1和γ_2,且γ_2>γ_1。两种液体的分界面为h。根据流体静力学,在深度为H处的压强P有如下关系: P=γ_1(H-h) hγ_2 =h(γ_2-γ_1) Hγ_1 当两种液体的重度γ_1、γ_2恒定,高度H恒定时,分界面h的变化就可以由压强P的变化反映出来。而压强P的变化,可以用差压变送器把它检测出来。所以,我们能够用差压变送器测定液体的分界面。这就是分界面测量的基本原理。     

难粘塑料的表面处理

本文对难粘塑料如聚乙烯(PE)、聚丙烯(PP)等聚烯烃和聚四氟乙烯(PTFE)、聚全氟乙丙烯(FEP)等含氟类高分子材料的表面处理技术进行了综述。     

用纯组分性质和无限稀释活度系数预测二元汽液平衡

本文从NRTL模型出发,通过合理假设,提出一个由γ_1~∞以及纯物性参数预测((dlnγ_1)/(dx_1))_x_1=0的斜率公式。用实测二元系的γ_1~∞和斜率公式算出的((dlnγ_1)/(dx_1))_x_1=0计算两参数过量自由焓模型参数,并进一步预测全浓度汽液平衡。     

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.     

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.     

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。