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991.
Field survey of the geometrical isomers of 7,9-dodecadienyl alcohol, acetate, and aldehyde has resulted in attractants and inhibitors for three species of tortricid moths.Epinotia silvertoniensis and an undescribedEpinotia sp. were all attracted to (Z,Z)-7,9-dodecadienyl acetate. AnotherEpinotia sp. was attracted to (Z,Z)-7,9-dodecadienyl acetate and (Z,Z)-7,9-dodecadien-1-ol. Electroantennogram data and inhibition patterns for one of theEpinotia sp. are also reported. In addition,E. criddleana was attracted to lures containing (E)-9-dodecenyl acetate.  相似文献   
992.
We propose a dynamic model for the copolymerization of α‐methyl styrene (α‐MS) and methyl methacrylate (MMA) in a batch reactor. The parameters are based on data from the literature and our own laboratories over the full conversion range. A two‐parameter model with constant reactivity ratios shows the most reasonable results. The dynamic model depicts the reaction kinetics and reactor behavior more clearly. Termination occurs mainly by the cross reaction of unlike radicals, and its rate increases with the molar ratio of α‐MS to MMA. The model enables us to predict the instantaneous and cumulative properties of the copolymer and also provides us with a basic tool for the optimization and control of industrial reactors. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 261–270, 2004  相似文献   
993.
以2,6-二氯吡啶为原料,制得2,6-二溴吡啶(收率79%)或2,6-二碘吡啶(收率56%),再分别与三氟乙酸钾反应,均可得标题化合物,收率28%~53%。该合成路线的优点是原料易得,反应条件温和,收率较高。  相似文献   
994.
GOR-C降烯烃催化剂的工业应用   总被引:6,自引:1,他引:6  
大庆炼化公司林源生产指挥部催化裂化装置原料油为典型石蜡基原油的常压渣油,生产的催化汽油中的烯烃含量较高,为此试用长岭炼化公司催化剂厂生产的降烯烃催化剂GOR-C。结果表明,降烯烃效果明显,产品分布无明显变化,能满足现有生产要求,经济效益显著。  相似文献   
995.
Acrylonitrile–EPDM–styrene (AES) graft copolymers were synthesized by solution graft polymerization of styrene (St) and acrylonitrile (AN) onto EPDM in an n‐hexane/benzene solvent with benzoyl peroxide (BPO) as an initiator. The structure changes were studied by an FTIR spectrophotometer. The grafting parameters were calculated gravimetrically. The influence of the polymerization conditions, such as the reaction time, concentration of the initiator, EPDM content, and weight ratio of St/AN, on the structure of the products was investigated. It was found that a proper initiator concentration and EPDM content will give a high grafting ratio of the AES resin. The thermal property of the copolymer was studied using programmed thermogravimetric analysis (TGA). The results showed that the copolymer has a better heat‐resistant property than that of ABS, especially for the initial decomposition temperature (Tin) and the maximum weight loss rate temperature (Tmax). Also, the mechanism of the graft reaction was discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 428–432, 2002  相似文献   
996.
沈良  王华彤  罗蒙贤 《化学世界》2002,43(8):416-418
报道一种有机过氧化物 2 ,5 -二甲基 -2 ,5 -双 (叔丁过氧基 )己烷 (简称双 2 5 )的合成新方法。研究了反应温度、过氧化氢浓度、反应物摩尔比以及反应物加入顺序对产品产率、品质的影响。该双2 5与硅橡胶硫化后的混炼胶物经各种性能测试 ,结果表明具有优良的性能  相似文献   
997.
E. Ito  K. Tajima  Y. Kobayashi 《Polymer》1983,24(7):877-882
This study was undertaken to elucidate the state of a polymer in the amorphous state through a change of motion of the molecular chain caused by heat treatment below the glass transition temperature. From dielectric measurements of amorphous poly(ethylene terephthalate) heat-treated below Tg, it was found that the average relaxation time, the distribution of relaxation time and the dielectric strength increase with increase of heat treatment. From these results, it was concluded that the amorphous state becomes more random by heat treatment.  相似文献   
998.
PTT/PP/PP-g-MAH共混材料的形态与性能研究   总被引:1,自引:0,他引:1  
研究了马来酸酐接枝聚丙烯(PP-g-MAH)对聚对苯二甲酸丙二酯(PTT)/聚丙烯(PP)共混体系的形态结构和性能的影响。结果表明,PP在PTT连续相中分散均匀,粒子尺寸随着增容剂含量的增加而细化,分散相与连续相之间有较好的黏结作用,PP-g-MAH改善了PP与PTT的相容性。共混物熔体为假塑性流体,其假塑性随PP-g-MAH含量的增加而升高,熔体表观黏度从1.31 Pa·s降低到1.19 Pa·s,黏流活化能从64.5 kJ/mol降低到36.7 kJ/mol。共混物中PTT和PP可分别结晶,但结晶行为相互影响,PP-g-MAH促进了PTT在高温结晶。共混物的冲击强度随着PP-g-MAH含量的增加从14.2 kJ/m~2提高到33.5 kJ/m~2,拉伸强度在PP-g-MAH含量为5%~10%(质量分数,下同)时最大。共混物的热稳定性随着PP-g-MAH含量的增加而逐渐降低。  相似文献   
999.
杨为华  肖国民  孔祥翔 《化学世界》2002,43(12):653-655
为开发六芳基二咪唑类光致变色材料 ,以联苯甲酰、对甲氧基苯甲醛及乙酸铵为原料 ,经过环合、氧化合成了光致变色化合物 2 ,2′-二对甲氧苯基 - 4,4′,5 ,5′-四苯基 - 1 ,2′-二咪唑。研究了多种因素对反应收率的影响 ,得到最佳工艺条件 :在冰乙酸中 ,联苯甲酰、对甲氧基苯甲醛及醋酸铵物质的量之比为 1∶ 1∶ 8,回流 3 h后生成 2 -对甲氧苯基 - 4,5 -二苯基咪唑 ,收率为 93 .6 % ;以乙二醇 -乙醚为溶剂 ,2 -对甲氧苯基 - 4,5 -二苯基咪唑与氧化剂 K3 [Fe(CN) 6]的物质的量之比为 1∶ 2 ,在 0~1 5°C下反应 5 h,得到产品 2 ,2′-二对甲氧苯基 - 4,4′,5 ,5′-四苯基 - 1 ,2′-二咪唑 ,收率为 87.5 %。  相似文献   
1000.
Platinum nanoparticles (n-Pt), over-grafted with 2-thiophenecarbonyl chloride are assembled on gold electrodes, by the Langmuir Blodgett (LB) technique using behenic acid (BHA) as promoting agent. These layers are electrochemically active without any preliminary activation. The [Fe(CN)6]3−/4− redox couple was used as electrochemical probe. This paper reports on the influence of the number of deposited LB layers, and the n-Pt density on the electrochemical response. n-Pt density was modified by the change of the “BHA/n-Pt” ratio. Cyclic voltammograms of “[Fe(CN)6]3−/4−” were observed whatever the coating conditions. As soon as the first layer was deposited the electrochemical response was associated to the n-Pt coverage, its response slightly increased up to a steady state for five or seven layers. As expected, the increase of the Pt density favored the increase of the current density. XPS analysis performed before and after electrochemical cycling showed that 4-mercaptoaniline capped platinum nanoparticles, and their over grafting were chemically and electrochemically stable. Analysis of influence of the number or the n-Pt density of the layers showed that the electrochemically active part of LB electrodes was provided by the last layer plus a part of the underlying one.  相似文献   
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