0 IntroductionConsidering the approximation of traditional design scheme on gear shaping cutter,we have given a new design model in paper[1],derived its CAD geometric model andverified that the new scheme is superior ...0 IntroductionConsidering the approximation of traditional design scheme on gear shaping cutter,we have given a new design model in paper[1],derived its CAD geometric model andverified that the new scheme is superior to the traditional one,but whether or not thenew designed cutter can be carried out with ordinary grinder is worth discussing fur-ther.This paper is to verifty the practicability of paper[1].展开更多
0 Introduction The ordinary gear shaper tools can be designed in traditional method. The detailed discussion is given in [1]. As for ordinary gear shaper cutters, due to their small rake angles, they may be designed a...0 Introduction The ordinary gear shaper tools can be designed in traditional method. The detailed discussion is given in [1]. As for ordinary gear shaper cutters, due to their small rake angles, they may be designed approximately by modifying their tooth profile angles. But for carbide ones, too small absolute value of rake angle is liable to cause breaking, while too large one results in excess design error. For this reason, we展开更多
采用固定床反应器,以Ni/Al 2 O 3为催化剂,研究了镍盐种类、载体焙烧温度、改性剂和钝化剂在环戊二烯选择加氢反应中对催化剂性能的影响。结果表明,X镍盐改性液作为活性组分,A物质作为钝化剂,经过T+200温度下焙烧的载体具有较好的催化活...采用固定床反应器,以Ni/Al 2 O 3为催化剂,研究了镍盐种类、载体焙烧温度、改性剂和钝化剂在环戊二烯选择加氢反应中对催化剂性能的影响。结果表明,X镍盐改性液作为活性组分,A物质作为钝化剂,经过T+200温度下焙烧的载体具有较好的催化活性,将载体进一步改性后,催化剂性能得到较大提升。将催化剂进行200 h长周期实验,结果表明催化剂具有较高的稳定性,环戊烯选择性保持在94%左右,环戊二烯转化率约在76%。展开更多
采用三段加氢工艺对煤基石脑油进行了加氢处理,重点研究了反应温度、压力、空速对一段加氢效果的影响,并对该段催化剂的使用寿命进行了考查,初步探讨了三段加氢反应温度对加氢性能的影响。研究结果表明经过三段加氢后的产品溴值小于1.0 ...采用三段加氢工艺对煤基石脑油进行了加氢处理,重点研究了反应温度、压力、空速对一段加氢效果的影响,并对该段催化剂的使用寿命进行了考查,初步探讨了三段加氢反应温度对加氢性能的影响。研究结果表明经过三段加氢后的产品溴值小于1.0 g Br/100 g,总硫小于0.5μg/g,可用于汽油调和组分、芳烃抽提或环保溶剂油。展开更多
文摘目的探讨妇科腹腔镜手术老年患者应用舒芬太尼复合异丙酚麻醉的应用效果。方法选取妇科腹腔镜手术老年患者70例,随机分为舒芬太尼组与瑞芬太尼组各35例。舒芬太尼、瑞芬太尼靶浓度分别为0.25 ng/ml、2 ng/ml,均复合靶浓度为2μg/ml的异丙酚。结果瑞芬太尼组在T1、T2和T5时SBP、DBP和HR与舒芬太尼组比较差异有统计学意义(均P<0.05);舒芬太尼组意识消失时间和异丙酚诱导剂量与瑞芬太尼组无显著性差异(均P>0.05),麻黄碱和阿托品使用率明显低于瑞芬太尼组(P<0.05);舒芬太尼组麻醉时间、自主呼吸恢复时间、呼之睁眼时间、拔管时间和定向力恢复时间均明显长于瑞芬太尼组(均P<0.05),术后镇痛药使用率明显低于瑞芬太尼组(P<0.05),而两组复苏室停留时间和术毕30 min OAA/S评分无显著性差异(均P>0.05);舒芬太尼组并发症明显少于瑞芬太尼组(P<0.05)。结论相比等效剂量的瑞芬太尼,舒芬太尼复合异丙酚麻醉血流动力学更加平稳,不良反应少,更适用于妇科腹腔镜手术老年患者。
基金Supported by Science Foundation of Heilonjiang Province
文摘0 IntroductionConsidering the approximation of traditional design scheme on gear shaping cutter,we have given a new design model in paper[1],derived its CAD geometric model andverified that the new scheme is superior to the traditional one,but whether or not thenew designed cutter can be carried out with ordinary grinder is worth discussing fur-ther.This paper is to verifty the practicability of paper[1].
基金Supported by Scienee Foundation of Heilongjiang Province
文摘0 Introduction The ordinary gear shaper tools can be designed in traditional method. The detailed discussion is given in [1]. As for ordinary gear shaper cutters, due to their small rake angles, they may be designed approximately by modifying their tooth profile angles. But for carbide ones, too small absolute value of rake angle is liable to cause breaking, while too large one results in excess design error. For this reason, we
文摘采用固定床反应器,以Ni/Al 2 O 3为催化剂,研究了镍盐种类、载体焙烧温度、改性剂和钝化剂在环戊二烯选择加氢反应中对催化剂性能的影响。结果表明,X镍盐改性液作为活性组分,A物质作为钝化剂,经过T+200温度下焙烧的载体具有较好的催化活性,将载体进一步改性后,催化剂性能得到较大提升。将催化剂进行200 h长周期实验,结果表明催化剂具有较高的稳定性,环戊烯选择性保持在94%左右,环戊二烯转化率约在76%。
文摘采用三段加氢工艺对煤基石脑油进行了加氢处理,重点研究了反应温度、压力、空速对一段加氢效果的影响,并对该段催化剂的使用寿命进行了考查,初步探讨了三段加氢反应温度对加氢性能的影响。研究结果表明经过三段加氢后的产品溴值小于1.0 g Br/100 g,总硫小于0.5μg/g,可用于汽油调和组分、芳烃抽提或环保溶剂油。
