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苯甲酸液相催化氧化合成苯酚 总被引:1,自引:0,他引:1
研究了苯甲酸液相空气催化氧化合成苯酚在2 L不锈钢反应器中进行的反应,考察了反应规律.通过单因子实验得最佳工艺条件为 反应温度230 ℃,空气流量4.5 l/min,搅拌转速600 r/min,催化剂质量分数4%(Cu) ,助催化剂质量分数2%(MA).通过均匀实验设计,建立了苯酚产率与相关实验条件在实验条件范围内的回归方程Y=47.15-0.915X1-0.57X2+2.895X3;重复实验收率达到80 %(摩尔分数).苯酚选择性达到90%(摩尔分数)以上,达到了工业化中试应用的要求. 相似文献
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采用分子筛法对提高异丙苯法合成的苯酚产品的质量进行了研究,探讨了使苯酚硫酸着色率(UVT)值达到指标要求(≥90%)的工艺条件。通过对苯酚原料的GC-MS分析和对原料与产品的UVT及总酮量分析,定性地说明了影响UVT值达标的主要杂质为沸点高于苯酚的酮类化合物。以Y型分子筛为催化剂研究了反应温度、反应时间及催化剂用量等因素对提高苯酚UVT值的影响。实验结果表明,在反应温度120-170℃、反应时间0.25-1.0h、反应催化剂用量为原料苯酚质量的0.25%-2.0%条件下,反应产物经适当减压精馏可得到UVT达到95%以上的高纯度酚。 相似文献
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在自行建立的管式反应器上,采用实验室开发的NY-2催化剂,以环氧乙烷(EO)吸收溶液和CO2为原料,进行合成碳酸乙烯酯(EC)连续过程研究.考察液空速、吸收溶液中EC与乙二醇(EG)摩尔比、EC与EO摩尔比、水含量、催化剂用量、反应压力和温度对反应的影响.通过实验研究,确定了较佳的连续反应条件:反应温度为(125±5)℃、反应压力为(3.5±0.5)MPa、催化剂质量分数不小于2%、吸收溶液中水的质量分数少于1.2%、EC与EO摩尔比为5、EG质量分数小于30%、空速小于0.67h^-1。在此条件下,EO的转化率大于98%,EC的选择性大于80%. 相似文献
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以2,4-二溴苯酚和POCl3在催化剂存在下合成多功能助剂BPP的方法及其应用,详细地研究了各种工艺参数对合成BPP的影响。结果表明:适宜的反应条件是2,4-二溴苯酚和POCl3的摩尔比为3.0-3.1:1,催化剂A用量为2,4-二溴苯酚重量的1.0%-1.5%,反应温度80-140℃,反应时间6-8h,BPP收率≥80%,应用研究表明:BPP阻燃性能和加工性能好,能改善材料的机械性能,对材料的透光性无影响,而且BPP还兼有避鼠和防霉性能。 相似文献
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以甲基叔丁基醚(MTBE)为烷基化试剂,通过正交实验研究了苯酚叔丁基化合成2,4-二叔丁基苯酚的反应规律,分别考察了一步法和两步法合成工艺的规律,结果表明:利用一步法,目标产物收率较高,在n(苯酚):n(MTBE)=1:2.1、反应时间60min、催化剂(浓硫酸)用量1.0mL、反应温度85℃时,目标产物的收率可达61.5%。 相似文献
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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. 相似文献
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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 总被引:15,自引:0,他引:15
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。 相似文献
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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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. 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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. 相似文献
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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. 相似文献
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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。 相似文献