微波法快速合成乳酸正丁酯

以乳酸和正丁醇为原料,硫酸氢钠作催化剂,利用微波技术合成了乳酸正丁酯;讨论了微波辐射功率、辐射时间、原料配比及催化剂用量等对酯化反应的影响。结果表明:较佳反应条件为n(正丁醇)∶n(乳酸)=3∶1,硫酸氢钠的用量为0.35 g,微波功率为462 W,辐射时间为7 min,酯产率达94%以上。     

微波辐射硫酸铁催化合成丙二酸二乙酯的研究

研究了利用微波辐射技术,在硫酸铁的催化下以丙二酸和无水乙醇为原料合成丙二酸二乙酯的反应,探讨了原料配比、反应时间、催化剂用量、带水剂、反应温度等对酯化率的影响。通过实验确定了最佳反应条件：n（乙醇）∶n（丙二酸）为3∶1,催化剂硫酸铁用量为1.0g,带水剂环己烷用量为20mL,微波辐射时间为10min,结果表明：该反应条件温和,方法简便,酯化率可达72.1%。利用折光率、红外光谱分析等对产品进行了物性、组成和结构表征。     

微波辐射下无溶剂催化合成乙酸辛酯

在微波辐射下,以硫酸氢钠为催化剂,不用溶剂,对乙酸与正辛醇之间的酯化反应进行了研究,考察了醇酸物质的量比、催化剂用量、微波辐射功率、微波辐射时间对乙酸辛酯收率的影响。结果表明,硫酸氢钠有着良好的催化活性,在正辛醇用量0.1 mol,n(正辛醇)∶n(乙酸)=1∶2.5,催化剂用量为反应物总质量的0.75%,微波功率450 W,辐射时间16 min条件下,乙酸辛酯收率可达91.2%,催化剂重复使用5次仍保持较高活性。     

响应面法优化4-丙烯酸羟丁酯的微波合成

研究了响应面法优化4-丙烯酸羟丁酯(4-HBA)的微波合成工艺过程研究。在合成工艺中利用微波辐射法,以1,4-丁二醇(BDO)和丙烯酸(AA)为主要原料合成4-HBA。以4-HBA的酯化率为考察指标,探讨了反应温度、微波辐射时间、微波功率、催化剂用量及醇酸摩尔比等单因素对酯化反应的影响。基于单因素实验,固定反应温度110℃、微波功率700 W,采用Box-Behnken响应面法对微波合成工艺过程中的微波辐射时间、催化剂用量及醇酸摩尔比3个参数进行优化,得出最优的合成工艺条件为:n(BDO)∶n(AA)=2.9∶1,催化剂用量为3.52%(对反应物总质量),反应时间为26 min,在此最佳实验条件下进行重复实验3次,得到4-HBA的酯化率为70.04%。     

丙酸丁酯的合成研究

研究了利用微波辐射技术,在对甲苯磺酸的催化下以正丙酸和正丁醇为原料合成丙酸丁酯的反应,探讨了原料配比、反应时间、催化剂用量、带水剂用量、微波功率等参数对酯化率的影响。结果表明:此法工艺简单,催化剂用量少,催化活性高,反应时间较短,正丙酸转化率高。通过实验确定了最佳工艺条件为:n(正丁醇)∶n(正丙酸)=1.8∶1.0,对甲苯磺酸用量0.3g,带水剂环己烷的用量5mL,微波功率595W,微波辐射时间10min,酯化率达99%以上。     

微波辐射SiO2负载磷钨酸催化合成丙酸苄酯

研究了微波辐射下,用SiO2负载磷钨酸催化剂直接催化合成丙酸苄酯的反应,考察了影响酯化收率的因素。其优化反应条件为催化剂用量0.5g(磷钨酸负载量20.2%),微波辐射功率450W、反应时间4.0min,n(丙酸)/n(苯甲醇丙酸)=1∶1,带水剂(环己烷)用量5mL,丙酸苄酯收率达83.4%。结果表明:相同条件下微波辐射-SiO2负载磷钨酸催化剂与常规加热-SiO2负载磷钨酸催化剂相比之下加快反应速度45倍,催化剂可重复使用。     

微波辐射下固体铁系超强酸催化合成己酸戊酯

采用自制的固体铁系超强酸催化剂,在微波辐射条件下,以己酸和戊醇为原料,合成己酸戊酯。探论了催化剂用量、己酸和戊醇的物料比、反应时间、反应温度四个因素对酯化反应的影响。实验所得到的最佳条件为:n(戊醇)∶n(己酸)=1.75∶1,催化剂用量为己酸质量的10.0%,反应时间16 min,反应温度为160℃,酯化产率可达94.78%。本方法具有反应时间短、反应条件温和、后处理简单且环保无污染等特点。     

SBA-15负载活性组分催化合成油酸乙酯

通过嫁接的方法合成Al-SBA-15介孔分子筛,以油酸和乙醇为原料,在间歇釜中进行酯化反应实验研究。考察反应温度、原料配比、催化剂用量、反应时间和催化剂硅铝原子比等因素对酯化反应的影响,结果表明,反应温度180 ℃、催化剂用量为原料质量的1.25%、n(油酸)∶n(乙醇)＝1.0∶2.5、反应时间5 h和催化剂硅铝原子比为10时,油酸转化率为83.53%。     

单模聚焦微波合成苯甲酸乙酯的研究

利用Discover单模聚焦微波精确有机合成系统,研究了标题化合物的合成反应.实验中考察了反应时间、反应温度、催化剂用量、微波功率及酸醇物质的量比的影响.实验结果表明,在最佳条件:n(浓硫酸):n(苯甲酸):n(乙醇)为0.54:1:3,微波功率为125 W,微波辐射温度70℃,微波辐射时间为15 min的条件下,酯化率可达84.9%.产物经傅里叶红外光谱的表征,证实与目标产物完全一致.     

微波促进硫酸铁铵催化合成环己酮乙二醇缩酮

用十二水硫酸铁铵作催化剂,微波辐射催化合成环己酮乙二醇缩酮。讨论了酮醇物质的量比、催化剂用量、微波功率和辐射时间对反应收率的影响。得出最佳反应条件为: n (环己酮) ∶n (乙二醇)=1∶1.4,催化剂用量为反应物总质量的3.5%,辐射功率450 W,辐射时间7 min,产物收率达88.1%。     

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.     

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。     

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.