高纯超微细凹凸棒土的制备及应用研究

采用超声振荡技术制备高纯度超微细凹凸棒土,通过粒径分布、FT-IR、XRD、SEM和TEM等方法对制得的凹凸棒土进行表征。结果表明在添加分散剂六偏磷酸钠的条件下,凹凸棒土的提纯效果明显优于酸处理的效果,其粒径分布比较均匀,颗粒较小,有效面积变大,分散性比较好。同时将纯化后的凹凸棒土用于粮食样品中锌的分离富集及含量测定,结果令人满意,相对标准偏差为2.6%～4.0%,加标回收率为96.00%～98.40%。     

聚酰胺66/凹凸棒粘土纳米复合材料的制备及其性能研究

对商品凹凸棒粘土提纯、钠化、有机化后,与聚酰胺66(PA66)经双螺杆共混挤出得到PA66/凹凸棒粘土纳米复合材料。用透射电镜(TEM)和扫描电镜(SEM)研究了PA66/凹凸棒粘土纳米复合材料的微观结构,并测试了复合材料的力学性能和热性能。结果表明,凹凸棒粘土在PA66中达到纳米级分散,凹凸棒粘土的粒径小于100nm,并且在合适的添加量时复合材料的拉伸强度和热性能都有一定程度的提高。     

负载纳米ZnO-TiO2凹凸棒土复合体的制备及表征

以凹凸棒土作载体,硫酸氧钛、硫酸锌及碳酸铵为原料,采用液相合成法制备负载纳米ZnO-TiO_2凹凸棒土(ATP/ZnO-TiO_2)复合粉体,借助XRD、FT-IR、TEM、EDS、UV-Vis对样品的组成结构、形貌和尺寸、表面化学成分、光吸收性能进行了表征。XRD、TEM、EDS结果表明:ZnO-TiO_2均匀、牢固的负载到凹凸棒土上,ZnO-TiO_2平均粒径为10 nm,TiO_2晶型为锐钛矿型; 450℃煅烧后复合粉体中才开始出现ZnO; 700℃煅烧后TiO_2仍未发生从锐钛矿向金红石型的晶型转变。     

简捷微波合成氧化锌纳米棒

以氯化锌和乙二胺的水溶液为前驱体溶液,采用家用微波炉微波辐照8min,成功制备出结晶性好的半导体ZnO纳米棒.用X-射线衍射(XRD)、选区成份分析(EDS)、场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)和选区电子衍射花样(SAED)对产物进行了表征.结果表明,纳米棒沿着c轴择优取向生长,直径在50nm左右,长度在400～600 nm之间,粒径分布均匀.并对ZnO纳米棒的生长过程进行了简单分析.     

纳米凹凸棒土的表面修饰及表征

在超声分散的条件下，通过溶胶-凝胶法制备了表面硅烷修饰的凹凸棒土纳米粒子(nano-attapulgite)。红外光谱(FTIR)、X射线光电子能谱(XPS)、透射电镜(TEM)、热失重(TGA)等研究方法表明，硅烷偶联剂(VTES)与凹凸棒土纳米微粒表面的残余羟基反应，形成了硅烷包覆的凹凸棒土纳米微粒，大约有12％的VTES包覆在纳米凹凸棒土的表面。最后给出了硅烷表面修饰凹凸棒土纳米微粒的结构模型．     

聚酰胺6／凹凸棒土纳米复合材料的结构与性能研究

用聚丙烯酸钠（PAAS）及六偏磷酸钠（SHMP）对凹凸棒土（ATP）进行分散、提纯和改性处理；利用透射电镜研究了其在水中的分散情况；利用热失重、红外和XRD对改性前后的ATP进行了表征。结果表明：PAAS及SHMP都能较好地分散ATP，PAAS对ATP的提纯改性效果要优于SHMP。在反应釜内通过水解开环聚合制备了聚酰胺6／凹凸棒土（PA6／ATP）纳米复合材料，利用XRD和DSC等测试手段分析了该复合材料的结晶结构；通过TEM分析了ATP在该复合材料中的分散情况，并测定了其力学性能。结果表明：ATP在PA6基体中分散较为均匀，当ATP用量为3．5％时，PA6的结晶度增加4．5％，材料的弯曲强度、弯曲模量和拉伸屈服强度分别较纯PA6提高33．7％、32．5％和29．4％。     

凹凸棒土反应填充HDPE制备纳米复合材料

在凹凸棒土表面吸附马来酸酐(MAH)单体和过氧化二异丙苯(DCP)引发剂，将处理过的凹凸棒土填充HDPE，制备HDPE／凹凸棒土纳米复合材料。结果表明，纳米复合材料的拉伸和冲击性能都有所提高，其中冲击性能提高了50％左右；用FT—IR，XRD，TEM等方法，对HDPE／凹凸棒土纳米复合材料的结构进行表征研究。     

黏土基二氧化钛水热制备及其光催化性能研究

以凹凸棒黏土为载体,氟钛酸铵为钛源,采用一步水热法制备了二氧化钛/凹凸棒黏土复合材料。通过X射线衍射(XRD)、拉曼光谱(Raman)、透射电子显微镜(TEM)、X射线能谱(EDS)、热失重(TG)、比表面积分析等,对二氧化钛/凹凸棒黏土复合材料进行了结构和形貌表征,并考察了其对罗丹明B的光催化性能。结果表明,二氧化钛/凹凸棒黏土是由平均直径约为25.8 nm的锐钛矿二氧化钛纳米粒子均匀负载于凹凸棒黏土表面而形成;二氧化钛/凹凸棒黏土保持了黏土的纳米棒状和多孔结构,比表面积为90.4 m2/g,平均孔径和孔体积分别为10.9 nm和0.28 cm3/g。二氧化钛/凹凸棒黏土具有良好的吸附特征和光催化活性,20 min对罗丹明B的暗吸附率为42.0%,紫外光照射60 min降解率达到98.1%。     

改性凹凸棒土填充硬质PVC的制备与性能研究

用硅烷偶联剂甲基丙烯酰氧丙基三甲氧基硅烷（MPTMS）和甲基丙烯酸甲酯（MMA）和凹凸棒土（AT）进行表面接枝改性，用傅立叶红外光谱分析了改性凹凸棒土的表面化学结构。以改性的凹凸棒土填充硬质聚氯乙烯（PVC），测试了材料的力学性能和热性能，结果表明，改性凹凸棒的填充可使PVC复合材料的拉伸强度，缺口冲击强度，弯曲强度，弯曲模量和热稳定性等均有所提高，用透射电镜观察了凹凸棒土及其在PVC基体中的微观分散状况，凹凸棒上具有纳米尺寸的针状结构，在PVC基体中以直径20nm-60nm,长度100nm-500nm的短纤维状分散在其中。     

纳米载银凹凸棒的一种新型制备方法及其载银机理研究

本文以纯化的凹凸棒为原料,在室温下采用原位还原的方法制备了纳米载银凹凸棒.利用X-射线衍射(XRD)技术分析了纳米载银凹凸棒晶体结构,发现纳米载银凹凸棒中凹凸棒晶面间距没有变化,同时有银的衍射峰出现.透射电子显微镜(TEM)对样品形貌的观察表明,粒径为8～11 nm纳米银颗粒较为均匀地负载到凹凸棒表面.样品的元素分析说明纳米载银凹凸棒中银含量为9.13%.红外吸收光谱(FT-IR)对纳米载银凹凸棒的表征结果证明纳米载银凹凸棒与纯凹凸棒光谱基本相同.研究表明在凹凸棒上成功载银,并提出了其载银机理.     

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.     

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.     

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。     

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。