乙酸芳樟酯的合成研究

以芳樟醇和醋酐为原料 ,无水K2 CO3为催化剂合成了乙酸芳樟酯。反应最佳工艺条件为 :醇酐质量比为 1∶1 2 ,催化剂用量为芳樟醇投料量的 4 % ,反应时间为 2 4h ,反应温度为 116± 2℃。芳樟醇转化率大于 95 2 % ,产品中乙酸芳樟酯含量大于 94 1%。     

对甲苯磺酸催化合成乙酸芳樟酯

以芳樟醇和乙酸酐为原料,对甲苯磺酸为催化剂,合成了乙酸芳樟酯。考察了反应温度、反应时间、催化剂用量和原料配比等因素对反应结果的影响。当n(芳樟醇)∶n(乙酸酐)=1∶2,反应温度15℃,催化剂用量为醇酐总质量的0 2%,反应时间150min时,乙酸芳樟酯的收率可达73 6%。与现有工艺相比,采用对甲苯磺酸为催化剂,具有反应温度低、反应时间短、不使用夹带剂和乙酸芳樟酯的收率比较高等优点。     

新型固体酸催化合成乙酸芳樟酯

通过直接负载法、溶胶一凝胶法制得STA／MXOY型固体酸催化荆，并用于合成乙酸芳樟酯的反应，其中STA／TiO2、STA／SnO2均显示出很高的催化活性。以催化活性较高的STA／TiO：为代表，详细考察反应温度、原料配比、催化剂用量和反应时间等因素对乙酸芳樟酯合成的影响。结果表明：反应温度为60℃，催化剂用量为4％，醇／酐摩尔比=1：2，反应时间为6h是最适宜的反应条件。     

强酸性阳离子交换树脂催化合成乙酸脱氢芳樟酯

采用强酸性阳离子交换树脂为催化剂,以脱氢芳樟醇和乙酸酐为原料合成乙酸脱氢芳樟酯,考察了离子交换树脂的处理方法、催化剂用量以及反应条件等因素对反应结果的影响。当n(脱氢芳樟醇):n(乙酸酐)=1:1.2、反应温度80℃、催化剂用量为醇酐总质量的5%、反应时间为3.5h时,反应的转化率和选择性分别达到80%和90%以上。     

月桂烯氢氯化物酯化反应定向性研究

在从β蒎烯合成若樟醇、香叶酸和橙花醇时,中间体萜烯基氯化物与无水醋酸钠酯化,所得芳樟基酯或香叶基酯的产量取决于酯化反应的选择性,本工艺采用新的定向选择催化剂C107及其相应的工艺条件,使生成乙酸芳樟酯的选择性达到85％以上。     

从香紫苏油中分离提纯芳樟醇和乙酸芳樟酯工艺的研究

采用真空间歇精馏技术,通过变换操作工艺条件,对香紫苏油进行分离得到芳樟醇和乙酸芳樟酯产品.考虑原料的热敏性制定出适宜的分离方案:首先在操作压力为1.5kPa条件下对原料进行初步分离,得到富含芳樟醇的轻馏分和富含乙酸芳樟酯的重馏分两个原料;再分别对轻馏分和重馏分进行不同条件下的真空间歇精馏,可以使芳樟醇的含量达到90.6%,乙酸芳樟酯的含量达到96.6%,满足两产品的不同需求.在提纯轻馏分中芳樟醇时,操作压力为5kPa,塔釜温度小于105℃;在提纯重馏分中乙酸芳樟酯时,操作系统压力为1.33kPa,塔釜温度低于110℃.此分离操作工艺,缩短了乙酸芳樟酯的受热时间、降低了分离温度以及乙酸芳樟酯因受热而异构化的趋势,降低了能耗.     

乙烯酮法合成乙酸芳樟酯

用160克芳樟醇和等摩尔量的乙烯酮在0.8克对甲苯磺酸催化下合成出乙酸芳樟酯,产率82％,纯度为97-98％。     

纯种芳樟叶油与芳樟叶酊（三）

(接上期P18)2百花香精纯种芳樟叶油24乙酸芳樟酯10铃兰醛6新铃兰醛6乙酸苄酯8甲位己基桂醛4玫瑰醇6乙酸对叔丁基环己酯5紫罗兰酮4香柠檬油5苯乙醇5水杨酸戊酯3玳玳叶油2香紫苏油2桂花净油2茉莉净油2玫瑰净油1卡兰加油3纯种芳樟叶含纤维素20-30%,半纤维素15-20%,木素10-15%,蛋白     

磺化聚芳醚酮酮催化合成顺丁烯二酸二丁酯

以交联的聚芳醚酮酮和20％发烟硫酸合成了磺化聚芳醚酮酮树脂，并用于顺丁烯二酸酐和正丁醇的催化酯化，最佳条件：醇：酐为2．5：1（物质的量比）；催化剂用量为2．5g，反应温度140－150℃，反应时间7h ，酯化率96．4％。气相色谱分析结果：顺丁烯二酸二丁酯的含量达99．96％，催化剂易回收且可重复使用。     

三氟乙酸钕催化合成乙酸环己酯

以三氟乙酸钕为催化剂,对环己醇与乙酸酐之间的酰化反应进行了研究,考察了催化剂用量、醇酐摩尔比、反应时间对乙酸环己酯收率的影响。结果表明,三氟乙酸钕有着较好的催化活性,当乙酸酐的加入量为0．1mol,醇酐摩尔比为1．1时,催化剂质量为0．25g,反应30min后,乙酸环己酯收率可达到92．2％,且催化剂重复使用5次仍保持较高活性,所得产品无色透明,具有很高的纯度。产品经折光率和红外光谱进行了表征。     

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.     

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.     

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。