沉积法制备Fe_3O_4/P(AA-DVB)磁性复合微球

通过静电吸附与机械力共同作用的沉积法制备得到了Fe3O4/P(AA-DVB)磁性复合微球。分别采用无皂乳液聚合和共沉淀法制备得到单分散的P(AA-DVB)胶体粒子及Fe3O4纳米粒子,在静电吸附和机械力作用下,将Fe3O4纳米粒子附着并嵌入P(AA-DVB)胶体粒子表面及内部,制备得到Fe3O4/P(AA-DVB)磁性复合微球。该方法的优势在于最终磁性复合微球的粒径及粒径分布可以由前驱体P(AA-DVB)胶体粒子调控。磁性复合微球表面和内部Fe3O4纳米粒子的分布及磁含量可以由机械力作用时间进行调节。所制备的Fe3O4/P(AA-DVB)磁性复合微球平均粒径为542 nm,磁含量范围在11%~33%内可调。     

隔氧水热反应制备单分散炭微球的实验研究

以葡萄糖为前驱物,在氮气保护氨水辅助的隔氧体系中水热合成单分散炭微球。考察了不同碳源、配料种类、氨水浓度和通氮时间对炭微球粒径分布和形貌的影响。采用SEM、BET、XRD、FT-IR、XPS、粒度仪对炭微球的形貌和成分进行表征,用差热法分析了炭微球的热稳定性。结果表明,氨水浓度与通氮气保护对炭微球的形貌与粒径分布影响显著,在0.1 g/m L葡萄糖溶液、0.05 mol/L氨水溶液和以200 cm3/min的速率通入氮气保护20 min的实验条件下,可制备出平均粒径为11.5μm且表面富含官能团—OH、CO、—COOH的单分散炭微球。     

漆酚缩甲醛聚合物微球的制备及其吸附性能

本文利用悬浮缩聚的方法合成漆酚缩甲醛聚合物微球,考察悬浮缩聚过程中单体的预分散、分散剂用量、单体的预聚、油水比例、催化剂用量、反应温度以及搅拌速度等对微球的形貌结构与性能的影响。结果表明,漆酚单体经预聚合后,在Mg(OH)2分散剂的作用下分散于甲醛水溶液中;在弱碱催化剂NH3·H2O的作用下,当油水比R=0.163时,搅拌速度r=300r/min时,于80℃～85℃进行悬浮缩聚反应,可以得到粒径为300μm,内部为多孔结构的聚合物微球。微球可以吸附废水中的重金属离子Cu2+、Pb2+和Cd2+等,其吸附选择性为Pb2+(21.9mg/g)Cu2+(21.3mg/g)Cd2+(7.1mg/g)。     

单分散二氧化硅微球的制备及其微观形貌的研究

以正硅酸乙酯(TEOS)为硅源、氨水为催化剂,通过溶胶-凝胶法合成了单分散的二氧化硅微球。通过控制单因素法研究了正硅酸乙酯用量、氨水用量以及反应温度对二氧化硅微球形貌和粒径的影响。利用扫描电镜(SEM)和傅立叶变换红外光谱仪(FT IR)对二氧化硅微球的微观形貌和化学结构进行表征研究。结果表明:成功制备了二氧化硅微球;并且二氧化硅微球的粒径会随着氨水用量的变大而变大,TEOS用量的变大而变大,温度的升高而减小;当氨水用量5mL、TEOS用量先加入3mL,后再加入7mL,反应温度为40℃时,制备的二氧化硅微球效果最佳。     

聚氨丙基/甲基倍半硅氧烷纳米球的合成与表征

以甲基三乙氧基硅烷(MTES)为前驱体,γ-氨丙基三乙氧基硅烷(KH550)为改性剂,氢氧化钠(Na OH)为催化剂,十二烷基磺酸钠/脂肪醇聚氧乙烯醚(SDS/AEO-9)为复合乳化剂,在水体系中通过乳液聚合制得了不同粒径、单分散的聚氨丙基/甲基倍半硅氧烷(PAMSQ)纳米球。用FTIR、XPS、TGA、DLS、FESEM及AFM等对PAMSQ纳米球的结构、耐热稳定性、粒径分布和微观形貌进行表征。结果表明,PAMSQ具有预期结构;TGA证实PAMSQ具有良好的耐热稳定性;单分散、规则球形的PAMSQ纳米粒子的粒径随Na OH浓度的增加而增加,当Na OH浓度为4.5~20.0 mmol/L时,PAMSQ的平均粒径在30~150 nm之间。     

SiO2单分散溶胶微球制备的工艺条件研究

在乙醇介质中,以氨作为催化剂,正硅酸乙酯作为硅源,制备了单分散的二氧化硅溶胶微球。通过激光粒度分析仪及透射电镜测定溶胶粒子的大小。研究了不同工艺参数如催化剂和水的量、硅源的量以及溶剂的类型对二氧化硅粒子大小及形貌的影响,并考察了粒子的形成机理。结果显示:随着氨浓度的升高,溶液初始解离的[OH-]增大,二氧化硅粒子的粒径增大;随着硅源浓度的增加,溶液中水解的中间产物增加,二氧化硅微球的粒径显著增加;在r(水/正硅酸乙酯)值远大于4的情况下,随着初始加入水量的增加,二氧化硅微球的粒径有所增加,但当水量太多时,粒径反而下降;使用不同溶剂作为制备二氧化硅的介质,在丙醇和丁醇中二氧化硅严重团聚,没有得到单分散微球。     

温度调控法合成单分散二氧化硅球

单分散性的纳米二氧化硅微球粒子在标准化、情报信息、分析化学、医学及生物化学、电子封装材料等许多科学领域中有着广阔的应用前景。采用在氨水(NH3·H2O)存在的条件下催化正硅酸四乙酯(TEOS)水解缩聚反应来制备单分散二氧化硅微球。与此同时通过改变氨水在体系中的浓度和实验温度使二氧化硅球的粒径得到了改变。然后通过扫描电镜、红外光谱、X射线衍射、反射光谱等仪器对微球进行了表征,结果表明通过温度调控法成功制备了粒径均匀的单分散二氧化硅微球。     

反应组分对单分散二氧化硅颗粒粒径的影响

以正硅酸乙酯(TEOS)为前驱体,氨水作为催化剂,在乙醇/水的混合体系中,制备了单分散球形二氧化硅溶胶粒子.通过正交试验设计,应用统计学方法对结果进行分析,研究了原料配比对二氧化硅胶体粒径的影响.结果表明:当固定反应温度(30℃)以及无水乙醇的用量(100 mL)时,TEOS、NH3、H2O的用量三个因素对于二氧化硅粒径的影响的大小顺序是:NH3＞TEOS＞H2O;在一定的浓度范围内,TEOS、NH3、H2O的用量的增加都会导致二氧化硅粒径变大.     

聚(苯乙烯-甲基丙烯酸)/银复合微球的制备与表征

本文采用单分散的聚(苯乙烯-甲基丙烯酸)(PSMAA)微球作为基材,在其表面通过静电作用吸附银氨离子([Ag(NH_3)_2]~+),通过聚乙烯吡咯烷酮(PVP)还原成银(Ag)纳米粒子,形成PSMAA/Ag微球。采用红外光谱(FTIR)、透射电镜(TEM)和X射线衍射(XRD)对PSMAA/Ag复合微球进行了表征,结果表明:Ag纳米粒子较为均匀地分布于PSMAA微球表面,Ag纳米粒子的粒径大约为15~40 nm。     

单分散氢氧化钙/聚苯乙烯微球的制备与表征

以葡萄糖水溶液为反应介质,在氧化钙消化成氢氧化钙的过程中,加入苯乙烯单体和引发剂,采用原位悬浮聚合法成功制备了聚苯乙烯(PS)包覆氢氧化钙[Ca(OH)2]形成Ca(OH)2/PS微球.考察了葡萄糖水溶液、苯乙烯、稳定剂聚乙烯醇以及反应温度对单分散Ca(OH)2/PS微球的粒径及粒子分散系数的影响,得出较佳合成条件.在较佳条件下制备的Ca(OH)2/PS微球平均粒径为30～40 μm,粒子分散系数为0.08～0.10.扫描电镜照片表明,Ca(OH)2/PS具有良好的球形度,表面光滑、无破损.红外光谱表征显示,产物为Ca(OH)2/PS微球.     

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。