对甲苯磺酸催化合成异丁叉二脲

对用对甲苯磺酸作催化剂湿法合成异丁叉二脲的反应进行了研究，通过实验，确定了其最佳工艺条件，异丁醛与尿素的用量比为1：2．8（摩尔比），催化剂对甲苯磺酸的用量为1％（对异丁醛的物质的量），反应介质水的用量为6：1（与尿素质量比），反应温度为35℃，反应时间为0．5h，产品产率可达96．5％。     

SO~(2-)_4 /TiO_(2-)MoO_3催化合成异丁醛1,2-丙二醇缩醛

以固体超强酸SO2-4/TiO2 MoO3为催化剂,对以异丁醛(Ⅱ)和1,2 丙二醇(Ⅲ)为原料合成异丁醛1,2 丙二醇缩醛(Ⅰ)的反应条件进行了研究。实验表明:SO2-4/TiO2 MoO3是合成异丁醛1,2 丙二醇缩醛的良好催化剂,较系统地研究了醛醇摩尔比、催化剂用量、反应时间诸因素对收率的影响。最佳反应条件为:n(异丁醛)∶n(1,2 丙二醇)=1∶1 3,催化剂用量为反应物料总质量的1 0%,环己烷为带水剂,反应时间1 0h。上述条件下,异丁醛1,2 丙二醇缩醛的收率可达82 5%。     

对甲苯磺酸催化合成丁醛乙二醇缩醛的研究

用对甲苯磺酸催化合成丁醛乙二醇缩醛,考察了催化剂的用量、反应时间、醛醇物质的量之比及带水剂等因素对合成反应的影响.实验结果表明:在丁醛和乙二醇的摩尔比为1∶1.5、催化剂用量为反应物料总质量的2.4%、环己烷为带水剂、反应时间40 min的优化条件下,丁醛乙二醇缩醛的收率可达91.91%.     

TiSiW_(12)O_(40)/TiO_2催化合成异丁醛1,2-丙二醇缩醛

以固载杂多酸盐TiSiW12 O40 /TiO2 为多相催化剂 ,对以异丁醛和 1,2 -丙二醇为原料合成异丁醛 1,2 -丙二醇缩醛的反应条件进行了研究。实验表明 :TiSiW12 O40 /TiO2 是合成异丁醛 1,2 -丙二醇缩醛的良好催化剂 ,较系统地研究了醛醇摩尔比、催化剂用量、反应时间诸因素对收率的影响。最佳反应条件为 :n(异丁醛 ) :n( 1,2 -丙二醇 ) =1:1.5 ,催化剂用量为反应物料总质量的 0 .5 % ,环己烷为带水剂 ,反应时间 1.0h。上述条件下 ,异丁醛 1,2 -丙二醇缩醛的收率可达 80 .2 % .     

缩二脲的合成新法

以对甲苯磺酸为催化剂 ,二甲苯为反应介质合成缩二脲 ,研究了二甲苯用量、催化剂量、反应时间、反应温度对反应产率的影响。结果表明 :当尿素、二甲苯、对甲苯磺酸质量比为 1∶1 2∶0 0 5 ,温度为 14 0℃ ,反应时间为 4h时 ,缩二脲收率可达 36 5 0 %。     

磷钨钼杂多酸催化合成丁醛乙二醇缩醛

用自制的磷钨钼杂多酸作催化剂,以丁醛和乙二醇反应合成了丁醛乙二醇缩醛.研究了原料物质的量比、催化剂用量、反应时间对产品收率的影响.结果表明,磷钨钼杂多酸对合成丁醛乙二醇缩醛有较好的催化活性,适宜的反应条件如下:n(丁醛)∶n(乙二醇)=1∶1.6、催化剂用量为反应物料总质量的0.4%、带水剂环己烷用量为10 mL、反应时间为60 min.在此优化条件下,丁醛乙二醇缩醛的收率可达68.1%.     

磷钨钼杂多酸催化合成丁醛1,2-丙二醇缩醛

以磷钨钼杂多酸为催化剂,丁醛和1,2-丙二醇反应合成丁醛1,2-丙二醇缩醛.考察了醛醇物质量比、催化剂用量以及反应时间诸因素对产品收率的影响.确定的适宜工艺条件为:n(丁醛)∶n(1,2-丙二醇)=1∶1.6,催化剂用量为反应物料总质量的0.6%,带水剂环己烷的用量为8 mL,反应时间45min.在此反应条件下,丁醛1,2-丙二醇缩醛的收率可达80.5%.     

HZSM-5分子筛催化合成1,3-苯并二口恶茂烷类化合物

研究了HZSM-5分子筛催化邻苯二酚与环己酮、丁酮、丙酮、丙醛、丁醛、异丁醛、戊醛、异戊醛、正己醛、正辛醛、苯甲醛、二苯甲酮等10余种醛(酮)的缩合反应。考察了反应时间、酚与醛(酮)的配比、HZSM-5分子筛用量等因素对邻苯二酚与醛(酮)反应的影响。结果表明,当n(邻苯二酚)∶n〔醛(酮)〕=1∶1.4,催化剂用量为3.5 g/mol邻苯二酚,反应5 h,选择性一般在99.2%以上,转化率也一般在30%以上,表明,HZSM-5分子筛对邻苯二酚与醛(酮)的反应有较好的催化性能。     

微通道反应器内合成羟基新戊醛

采用Vapourtec公司的Flow Chemistry System微通道反应器,研究了甲醛和异丁醛在三甲胺的催化下合成羟基新戊醛(HPA)的反应,考察了反应温度、原料配比、催化剂用量、停留时间对异丁醛转化率和HPA选择性的影响。获得的较优反应工艺条件为:反应温度为120℃、停留时间为150 s、催化剂三甲胺的用量为2%、n(甲醛)∶n(异丁醛)=1.05。在该优化工艺条件下,异丁醛的转化率为97.4%,HPA的选择性为94.3%。与传统间歇釜式工艺相比,连续流微通道反应器通过大幅提高体系的反应温度大大缩短了反应停留时间。     

微波辐射催化合成乙酸异戊酯

以乙酸与异戊醇为原料,对甲苯磺酸为催化剂,微波辐射催化合成了乙酸异戊酯,优化了合成条件。结果表明,n(异戊醇)∶n(冰醋酸)=1∶1.45,催化剂用量2.10 g,反应温度100℃,反应时间5 min,微波功率440 W,此时产品收率达78.3%。     

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。