织物形式对丙纶纤维/PP复合材料的影响

分别采用平纹、斜纹编织的丙纶长纤维与聚丙烯树脂(PP)经热压成型制备丙纶纤维/PP复合材料。比较两种编织形式对复合材料力学性能的影响,并通过扫描电子显微镜(SEM)及动态力学分析(DMA)对复合材料的微观形貌、热性能进行分析。结果表明,不同织物形式具有不同的浸润性能,并直接影响复合材料的力学性能。总体而言,斜纹丙纶纤维增强PP的拉伸性能及弹性模量要高于平纹织物增强PP;而平纹丙纶纤维增强PP的冲击强度要高于斜纹丙纶纤维增强PP。从SEM结果可以看出,15 phr丙纶纤维与PP树脂相容性较好,并且斜纹丙纶纤维与基体之间的间隔比平纹丙纶纤维与基体之间的间隔更小。DMA分析表明,斜纹丙纶纤维增强PP的玻璃化转变温度更大。     

增强体织物组织结构对曲面复合材料力学性能的影响

为了探究曲面复合材料中增强体织物组织结构对其力学性能的影响,采用不同组织结构（平纹、斜纹、缎纹、无纬结构）的玄武岩织物,浸渍在环氧树脂与固化剂混合溶液中,在特制模具中加压复合成型制备了一系列曲面复合材料。采用3点弯曲试验法对曲面复合材料的弯曲强度和弯曲模量进行了测试,并且研究了曲面复合材料的冲击性能以及顶破强力及其破坏机理。结果表明,平纹增强体的玄武岩曲面复合材料弯曲性能最佳;组织结构为缎纹的玄武岩曲面复合材料冲击性能最佳,弯曲强度和平纹相近,在顶破强力上缎纹结构略低于斜纹结构。     

玄武岩纤维/酚醛树脂基复合材料性能研究

对玄武岩纤维增强酚醛树脂基复合材料进行了实验研究。制备了连续玄武岩纤维平纹织物增强酚醛树脂复合材料。研究了胶含量对玄武岩纤维/酚醛树脂复合材料拉伸、压缩和层间剪切强度等力学性能、耐烧蚀性能的影响。利用SEM对复合材料压缩、层间剪切破坏断口和烧蚀试样的微观形貌进行了分析。研究结果表明,玄武岩纤维/酚醛树脂复合材料具有较好的界面性能,树脂含量在36%时CBF/酚醛树脂复合材料的力学性能最佳,线烧蚀性率和质量烧蚀率最低。     

玄武岩纤维增强不饱和聚酯层压复合材料低速冲击损伤性能

研究0°单向、0°/90°交错和平纹织物三种不同铺层方式玄武岩纤维增强复合材料低速冲击加载力学性能。在实验中,通过手糊成型法并在硫化机上加热加压制备层压复合材料,且在Instron9250落锤冲击测试仪上完成层压复合材料低速冲击试验,得到载荷-挠度曲线和载荷-时间曲线,用于分析三种不同铺层方式玄武岩纤维增强不饱和聚酯树脂层压复合材料低速冲击加载力学性能。通过观察层压复合材料破坏形态来分析其破坏方式。实验结果表明:0°/90°交错层压复合材料和平纹织物增强层压复合材料抗低速冲击性能优于0°单向层压复合材料;0°单向层压复合材料破坏方式为裂纹沿着纤维方向伸展,而0°/90°交错层压复合材料和平纹织物层压复合材料破坏只发生在冲击点附近局部区域。     

玄武岩纤维表面处理对尼龙6复合材料力学性能影响

为改善玄武岩纤维增强PA6复合材料的力学性能,对玄武岩纤维分别进行了H2SO4处理、偶联剂KH-550处理及H2SO4加KH-550协同处理,使用双螺杆挤出机制备了玄武岩纤维质量分数分别为10%、20%、30%的复合材料,测试复合材料的拉伸和冲击性能,并对纤维以及复合材料冲击断面进行微观表征。结果表明,随着玄武岩纤维质量分数的增加,复合材料的力学性能有较大提升。此外,经过协同处理、玄武岩纤维质量分数为30%的复合材料相较于纤维含量相同但未经处理的复合材料,拉伸强度提高了24.36%,冲击强度提升了37.41%。     

玄武岩纤维及其增强水泥基复合材料研究进展

玄武岩纤维是一种新型无机绿色环保高性能纤维材料.综述了玄武岩纤维及其玄武岩纤维增强水泥基复合材料(basalt fiber reinforced cement-based composite)国内外最新研究进展,简要介绍了玄武岩纤维国内外研究进展,玄武岩纤维表面处理技术对界面性能的影响以及对提高复合材料整体性能的必要性,并重点介绍了玄武岩纤维增强水泥基复合材料力学性能研究和纤维增强机理以及玄武岩纤维水工混凝土及BFRP加固应用.最后对玄武岩纤维增强水泥基复合材料的发展研究方向进行了展望.     

连续玄武岩纤维增强9518G树脂复合材料性能的研究

研究了连续玄武岩纤维增强9518G树脂复合材料的耐热性、力学性能和湿热对力学性能的影响,结果表明连续玄武岩纤维增强9518G树脂复合材料的玻璃化转变温度为199.11℃,具有较好耐热性;力学性能良好,与E玻璃布复合材料的力学性能相当;煮沸150 h后材料的力学性能最小保持率和最大吸水率分别为67.1%和0.35%。     

玄武岩纤维增强聚丙烯基复合材料的力学性能研究

本文主要研究玄武岩增强聚丙烯复合材料的力学性能。分别制备了玄武岩纤维含量为10%、20%、30%和40%的纤维增强复合材料,并分析纤维含量对复合材料拉伸性能和弯曲性能的影响。研究表明,玄武岩纤维的加入大幅度提高了复合材料的拉伸性能和弯曲性能,但复合材料的断裂伸长率有所下降;随着玄武岩纤维含量的增加,复合材料的拉伸、弯曲强度和模量呈先增加后减小的趋势,当纤维含量在30%时达最大值;复合材料的弯曲强度和模量的变化规律与拉伸性能相同。     

一种耐腐蚀高性能玄武岩纤维增强双马来酰亚胺/呋喃复合材料

正本发明涉及一种耐腐蚀高性能玄武岩纤维增强双马来酰亚胺/呋喃复合材料,属于热固性树脂材料技术领域。所述复合材料由双马来酰亚胺5～25份、呋喃树脂100份、对甲苯磺酸固化剂3份和总树脂70 wt%左右的玄武岩纤维布组成。本发明制备的玄武岩纤维增强双马来酰亚胺/呋喃复合材料具有更好的力学性能和耐化学腐蚀性能。专利公布号:CN110317429A     

剑麻纤维/玄武岩纤维混杂增强聚乳酸复合材料的力学性能研究

混杂纤维增强复合材料由于可以综合利用各种纤维的优点,极大地提高复合材料的性能,拓展复合材料的适用范围。采用剑麻纤维和玄武岩纤维混杂增强聚乳酸制备复合材料,研究了纤维含量和铺层顺序对混杂纤维复合材料力学性能的影响。结果表明,剑麻纤维作为芯层、玄武岩纤维作为表层时混杂复合材料具有较好力学性能。当纤维质量分数为40%时,其拉伸强度和冲击强度比纯聚乳酸分别提高了2.83倍、41.47倍,达到了267.29 MPa和183.46k J/m~2;纤维含量为30%时,其弯曲强度比纯聚乳酸提高4.07倍,达到354.16 MPa。     

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.     

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。     

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.     

基于ATRP法制备的触角状亲水性羟胺树脂的吸硼性能的研究

以大分子引发剂氯乙酰化聚苯乙烯微球(PS-acyl-Cl)经原子转移自由基聚合(ATRP)法引发丙烯酰胺(AM)和甲基丙烯酸缩水甘油酯(GMA)单体的共聚接枝,制得一种触角状亲水性环氧载体(PS-acyl-g-P(AM-co-GMA)),再经二乙醇胺(DEA)的环氧基开环胺化反应,得到一种含多个-NCH2CH2OH螯合配基的多齿-五元螯合环的触角状亲水性羟胺树脂(PS-acyl-g-P(AM-co-GMA)-DEA)。将此树脂用于硼吸附研究,结果表明,PS-acyl-g-P(AM-co-GMA)-DEA树脂对硼的吸附满足Langmuir方程,为单分子层吸附;饱和吸附量约为37.7 mg·g-1,且树脂5 min即可达到吸附平衡,与其它已报道的吸硼树脂相比,该树脂具有更高的吸附量和吸硼速率。吸附动力学研究表明,树脂吸附硼的过程主要由颗粒扩散过程控制。重复使用5次后该树脂的吸附量基本不变,解吸率均在90%以上,重复使用性能良好。