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PREPARATION OF ETHYLENE GLYCOL ACETATE THROUGH CATALYTIC OXIDATION OF ETHYLENE——ONE-STEP PROCESS WITH SIMULTANEOUS INTRODUCTION OF OXYGEN AND ETHYLENE INTO A Pd-Cu CATALYTIC SOLUTION 下载免费PDF全文
Ethylene glycol acetate can be prepared from ethylene by employing PdCl_2-CuCl_2-Cu(OAc)_2 in anacetic acid solution,usually involves two steps-acetoxylation and the regeneration of catalyst.In thispaper,a one-step process has been studied with oxygen and ethylene introduced simultaneously in a singlereactor.It was observed that there must be enough partial pressure of oxygen to oxidize Cu~+ to Cu~(2+)by keeping oxygen content at 8-10% in the raw binary gas mixture of oxygen and ethylene,whereby theactivity of the catalytic system could be maintained without formaton of CuCl residue.By using nitrogen as a diluent,the ratio of O_2/C_2H_2 could be kept in the non-explosive range.Itis claimed that 95% of the converted ethylene from the feed gas exists as ethylene glycol monoacetateand diacetate. 相似文献
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2005~2007年连续3年5次采集辽宁省粮食、蔬菜主产区地下水样品1000余个,利用TU-1810DASPC紫外可见光光度计测定硝酸盐含量.结果表明:粮食、蔬菜主产区地下水硝酸盐含量平均值为17.37mg L-1,硝酸盐含量小于20mgL-1的样品占70.53%,大于20mg L-1的样品占29.47%.保护地蔬菜产区农户饮用水硝酸盐含量平均值为21.19mg L-1,个别的蔬菜种植户地下水硝酸盐含量达到396.67mg L-1,超出国家安全饮用水标准15倍以上.水稻产区地下水硝酸盐含量平均值为19.14mg L-1,玉米产区地下水硝酸盐含量为14.21mg L-1.部分监测区域地下水硝酸盐含量超出安全饮用水标准13.0%~28.1%.不同县区地下水硝酸盐含量超标率排序为新民市53.75%>开原市42.35%>辽中县41.75%>黑山县33.46%>北镇市31.51%>铁岭县28.87%>昌图县28.33%>新城子区12.50%>于洪区10.00%>苏家屯区9.00%. 相似文献
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汪仁樹 《哈尔滨工业大学学报》1959,(1)
在近代机械工业中行星齿轮机构得到了广泛的应用。如用作差动机构、高传动比机构、减速箱及变速箱等。本文仅研究行星齿轮变速箱的示意图设计。与普遍齿轮变速箱比较起来行星齿轮变速箱的缺点是结构复杂、制造和装配困难。因此,行星齿轮变速箱目前只用于特别需要操纵方便的地方:为坦克、汽车及履带式拖拉机等机器上。据目前新知,在这些地方也还仅限于采用二自由度行星变速箱。实际上,在很多情况下采用三自由度行星齿轮变速箱则更为有利,因为它的结构较为简单。因此,研究三自由度行星变速箱具有很大的实际意义。行星齿输变速箱示意图的设计也是很困难的,特别是三自由度的。本文所提的方法 相似文献
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江阴新达塑机有限公司专业制造填补国内空白的 SJW往复式单螺杆混炼挤出机可对物料进行剪切、取向、切割、折叠、拉伸、再取向达到高效的分散混合效果。其特点是其螺纹不连续 ,每转一圈中断三次 ,并往复一次。剖分式机筒可快速打开清理物料 ,内表面按一定规律安装三排可调整、更换的捏合销钉卡适合不同的工艺要求 ,带孔的销钉可装传感器 ,螺杆芯轴内可加热或冷却。用途广泛可用于阻燃料、电缆料、热敏性塑料(如 :PVC、过氧化物交联料或硅烷交联料 )、热固性复合材料的连续化生产填补国内空白的往复式单螺杆混炼挤出机@汪仁… 相似文献
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In this paper,various techniques including BET,XRD,SEM and XPS were used to study the sintering ofpure and La_2O_3-doped titania.The experimental results show that sintering of titania proceeds via volume diffu-sion.Adding of lanthanum oxide decreases the rate of sintering and hinders the phase transition from anatase torutile crystal by strong surface interaction between the mixed crystals(La_4Ti_9O_(24),La_(0.66)TiO_(2.99))and TiO_2. 相似文献