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31.
水和甲醇存在下MAMS的消失反应动力学研究   总被引:1,自引:0,他引:1  
通过实验研究了甲基丙烯酰胺硫酸盐(MAMS)与甲醇、水进行反应的动力学,并对该反应的机理进行了探讨。  相似文献   
32.
二氢茉莉酮酸甲酯生产工艺的研究   总被引:2,自引:0,他引:2  
二氢茉莉酮酸甲酯是一种深受人们喜爱的茉莉香型的重要香原料。本文以环戊酮和戊醛为原料在碱催化下 ,以缩合和异构化反应合成了 2 -戊基环戊烯酮。 2 -戊基环戊烯酮再与丙二酸二甲酯缩合 ,脱羧得二氢茉莉酮酸甲酯 ,并且进行了中试放大 ,确定了最佳工艺条件  相似文献   
33.
仲丁醇含量对正丁烯直接水合法制仲丁醇的影响   总被引:1,自引:0,他引:1  
曾岳飞 《辽宁化工》2004,33(3):164-166
研究了正丁烯直接水合法制仲丁醇工艺中原料水中仲丁醇含量对反应的影响.当原料水中含有少量仲丁醇时(约0.9%时),其对水合反应过程的转化率影响不大;原料水中含有少量仲丁醇时,反应过程的稳定性比较好.当水合反应的原料水中仲丁醇浓度增大时(原料水中仲丁醇浓度为2.0%左右时),反应过程的转化率明显下降.当水合反应的原料水中仲丁醇含量进一步增大时,反应过程的转化率下降明显,但呈非线性变化.  相似文献   
34.
Evidence for recruitment and retention of beneficial insects in grapes and hops using controlled-release dispensers of methyl salicylate (MeSA), a component of herbivore-induced volatile blends, is presented. In a replicated experiment conducted in a juice grape vineyard, sticky cards in blocks baited with MeSA captured significantly greater numbers of five species of predatory insects (Chrysopa nigricornis, Hemerobius sp., Deraeocoris brevis, Stethorus punctum picipes, Orius tristicolor) than unbaited blocks. Four insect families (Syrphidae, Braconidae, Empididae, Sarcophagidae) were also significantly more abundant in the MeSA-baited blocks, as indicated by sticky card captures. Canopy shake samples and sticky card monitoring conducted in a MeSA-baited, unsprayed hop yard indicated development and maintenance of a beneficial arthropod population that was nearly four times greater than that present in an unbaited reference yard. Four times as many S. punctum picipes and six times as many O. tristicolor were sampled in the MeSA yard. Similar contrasts in abundance of these predators and others were apparent when compared with levels recorded in the yard in previous years. The large population of predatory insects in the MeSA-baited hop yard was associated with a dramatic reduction in spider mite numbers, the major arthropod pest of hops, in late June, and subeconomic populations were maintained for the rest of the season. The evidence presented here is highly suggestive that the use of controlled-release MeSA in a crop could increase recruitment and residency of populations of certain beneficial insects. This strategy may have the potential to enhance the efficacy and reliability of conservation biological control in crop pest management.  相似文献   
35.
VAc/MMA半连续乳液共聚合的研究:Ⅰ种子乳液共聚合   总被引:2,自引:3,他引:2  
以过硫酸铵为引发剂,十二烷基硫酸钠为乳化剂,于70℃下进行了VAc=MMA种子乳液共聚合。试验考察了组分和操作条件对体系稳定性,聚合速度及组成分布等的影响,同时,从理论上给出了加料速率与体系稳定性因子间的关系。  相似文献   
36.
甲基对硫磷在小白菜上的降解动态及最终残留量   总被引:2,自引:0,他引:2  
为了解甲基对硫磷在小白菜上的降解动态及最终残留量,指导该农药的使用,给安全食用小白菜提供科学依据,该试验在银川郊区银新乡农户的温室菜棚中进行。喷药后第零天,第一天,第二天,第三天,第五天,第七天,每天分别取样,用气相色谱法分析测定甲基对硫磷在小白菜上的残留量,得出甲基对硫磷残留量(Y)与时间(t)的关系。实验结果表明,甲基对硫磷在小白菜上半衰期为2.91天;喷药后第七天,在小白菜中未检出甲基对硫磷的残留。  相似文献   
37.
The damage effects and mechanisms of proton irradiation with 50-200 keV energy to space-grade methyl silicone rubber was performed using a ground-based simulator for space irradiation environment. The changes in surface morphology, mechanicai properties, cross-linking density, glass temperature, infrared attenuated total reflection spectrum, mass spectrum and pyrolysis gas chromatography-mass spectrum indicated that, under lower energy, the proton irradiation would induce cross-linking effect, resulting in an increase in tensile strengths and hardness of the methyl silicon rubber. However, after the irradiation of protons for more than 150 keV, the irradiation induced degradation, which decreased the tensile strengths and hardness, became a dominant effect. A macromolecular network destruction modei for the silicone rubber radiated vvith the protons was proposed.  相似文献   
38.
The conversion of fatty acid methyl ester (FAME) from triglycerides using heterogeneous catalysis has gained increasing interest due to the prospect of increased yield at reduced operating costs and reaction conditions. In this paper, meso-porous hydrotalcite was used to catalyze jatropha oil into FAME with relatively higher yield at atmospheric pressure and relatively low reaction temperature. The molar ratio of methanol to oil required was relatively low and the conversion was completed within few hours of reaction time. The reaction was promoted when moderate calcination temperature was applied, the disordered structure of the catalyst was maintained, counterbalance anions was removed, and phase transitions within the oxide lattice was induced. Despite the observed deactivation during successive reaction cycles due to adsorption of residual triglycerides, the catalyst performance was restored effectively by air-re-calcination.  相似文献   
39.
40.
This study established the inactivation kinetic parameters of some pathogenic bacteria including Escherichia coli O157:H7, Salmonella enterica serotypes, and Listeria monocytogenes; and spoilage yeasts namely, Debaryomyces hansenii, Clavispora lusitaniae, Torulaspora delbrueckii, Pichia fermentans, and Saccharomyces cerevisiae in orange juice subjected to multi-frequency Dynashock power ultrasound treatment. All test organisms exhibited a biphasic inactivation behavior with a sigmoidal inactivation curve consisted of an initial inactivation lag, followed by logarithmic linear inactivation. Injury accumulation in the inactivation lag phase was established in acid-adapted bacteria. The time necessary to reduce initial inoculated populations by 5 log cycles (99.999%), T5D values, significantly increased with acid adaptation. The T5D of E. coli, S. enterica, and L. monocytogenes increased from 37.64, 36.87, and 34.59 respectively; to 54.72, 40.38, and 37.83 min respectively after acid exposure. Temperature increase due to sensible heat propagation during ultrasound treatment decreased the resistance of the test bacteria. The cocktail of E. coli O157:H7 had significantly greater resistance towards ultrasound treatment (T5D = 54.72 min) than any of the individual strain (T5D = 41.48–47.48 min) in the mix. Similar results were found in the composited (T5D = 60.02 min) and individual species (T5D = 20.31–59.04 min). The results established in this work provide baseline information on microbial behavior in multi-frequency ultrasound-treated orange juice for establishment of pasteurization process schedules.  相似文献   
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