过氧化氢氧化苯甲醛制苯甲酸的研究

以过氧化氢为氧化剂,十六烷基三甲基钨磷杂多酸铵为催化剂,催化氧化苯甲醛制苯甲酸.考察了反应温度、催化剂用量、30%过氧化氢用量和反应时间对苯甲酸产率的影响.结果表明：苯甲醛10.1 mL,30%过氧化氢11.5 mL,催化剂0.16 g,90℃下反应6 h,苯甲酸的产率可达到74.9%.     

超临界CO2中甲苯氧化为苯甲醛的研究

研究了超临界CO2介质中过氧化氢氧化甲苯生成苯甲醛的均相氧化反应。实验考察了无催化剂条件下影响苯甲醛收率的因素。研究发现,在压力25MPa。温度180℃,反应时间4h。过氧化氢与甲苯摩尔比为2．5的条件下,苯甲醛的收率为1．535％,此时的氧化反应可近似为1级反应,反应活化能为21．5KJ／mol。     

近临界水中甲苯氧化成苯甲醛的工艺研究

研究了在近I临界水中,无催化剂条件下,用过氧化氢作为氧源,氧化甲苯生成苯甲醛。并研究厂甲苯在近临界水中氧化成苯甲醛的化学工艺：对反应参数(反应温度,反应时间、过氧化氢用量)对苯甲醛收率的影响进行了详细的实验研究。研究结果表明,在350℃,反应时间为60min,n[N2O2]：n[甲苯]为35的最优化条件下,苯甲醛的收率可达17.4％。研究结果显示,合理地控制过氧化氢用量,可避免副反应的发生,当n[H2O2]2:n[甲苯]小于或等于2．2时,可以减少苯酚、p-甲酚等副产物的生成。该方法以水为溶剂,且避免了使用催化剂,对环境无污染。     

1∶12系列多金属氧酸盐催化苯甲醛氧化反应的研究

以苯甲醛为原料,过氧化氢作氧化剂,1∶12磷钨杂多酸哌啶盐为催化剂,一步反应制得苯甲酸。考察了反应温度、物料比、催化剂用量及反应时间对反应的影响。反应产物抽滤烘干后,通过测熔点来进行分析。采用正交实验法对苯甲酸的合成路线进行优化设计,得出了最优化工艺条件:温度75℃,V(苯甲醛)∶V(过氧化氢)=1∶3.0,m(催化剂)=0.4 g,反应时间5 h,苯甲酸产率达96.7%。     

合成2-叔丁基-4-甲基苯酚的优化作

以对甲基苯酚和异丁烯为原料，以浓硫酸为催化剂，选择性合成2-叔丁基-4-甲基苯酚，考察了反应温度、反应时间和催化剂用量等因素对合成2-叔丁基-4-甲基苯酚转化率和收率的影响。结果表明，在反应温度75℃，催化剂用量4％，反应时间45min时，2-叔丁基-4-甲基苯酚合成转化率达94．5％，产物收率为86．2％。     

一种绿色正十二烷基甲基亚砜制备工艺研究

开发了一种绿色环保的标题物质制备工艺。第一步,用碳酸二甲酯对正十二硫醇进行单甲基化合成中间产物正十二烷基甲基硫醚:以碳酸钾为催化剂,碳酸二甲酯既为甲基化试剂又为溶剂,反应温度105℃,正十二硫醇与碳酸二甲酯投料质量比1︰5,催化剂用量7%,反应时间16 h,产率达89%。第二步,用过氧化氢对中间产物正十二烷基甲基硫醚进行选择性氧化制备标题物质:以四氢呋喃为溶剂,以少许浓硫酸为催化剂,正十二烷基甲基硫醚与过氧化氢(质量浓度30%)按质量比1︰4投料,最佳反应条件:反应温度30~40℃,反应时间为6~8.5 h,产率达70%(按原料正十二硫醇用量计)。通过熔点测定和质谱分析对目标产物进行了表征。     

对二甲氨基苯甲酸乙酯的合成研究

本文以对二甲氨基苯甲酸和乙醇为原料合成了增感剂对二甲氨基苯甲酸乙酯。最佳反应条件是：反应温度78℃，原料对二甲氨苯甲酸与乙醇的摩尔投料比为1：80，反应时间2h ,催化剂浓硫酸的用量为2ml，在上述条件下进行实验产品收率为48．3％，用熔点，元素分析，红外光谱表征了该化合物的结构。     

合成实验肉桂酸的改进

用氟化钾作催化剂，对肉桂酸的合成工艺进行了改进研究，最佳反应条件以氟化钾为催化剂，苯甲醛：乙酐=1：2，反应时间1h，反应温度为150-170％，收率可达74．5％，降低了反应温度，缩短了反应时间，提高了产率。     

硼钼酸(哌啶)盐晶体的合成及性能研究

实验制备了硼钼酸盐,并通过XRD,IR对样品的结构进行了分析,通过热重(TG)对样品的热稳定性进行了分析。以苯甲醛为原料,过氧化氢作氧化剂,以[(CH_2)_5NH_2]_5BMo_(12)O_(40)为催化剂,考察了催化剂用量、物料配比、反应时间、反应温度对产物收率的影响。确定最佳反应条件:n(催化剂):n(苯甲醛)=1.847×10~(-3):1;n(H_2O_2):n(苯甲醛)=4.70:1;反应温度80℃;反应时间4h。苯甲酸的收率达到85%以上。     

2-甲基-3-喹啉甲酸的酯化反应研究

以2－甲基－3-喹啉甲酸为原料,在浓硫酸作为催化剂的条件下与乙醇发生酯化反应合成了标题化合物。对它的合成工艺条件进行了探索和优化,优化的最佳反应条件是2－甲基－3－喹啉甲酸,乙醇和浓硫酸的投料比为1．0mmol：1mL：0．2mL;反应时间为2h,收率为68．1％。优化后的合成方法具有反应时间短、产率较高等优点。     

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。     

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.     

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.     

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。