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41.
介绍了可编程控制器(PLC)在超声波清洗机控制系统中的应用,对系统的硬件和软件作了详细的阐述。 相似文献
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目的通过肺组织NF-κB的表达,研究羟乙基淀粉130/0.4复苏对失血性休克大鼠肺损伤保护作用的可能机制.方法健康雄性SD大鼠54只,体重230~280 g,随机分为3组:对照组(C组)、乳酸林格氏液复苏组(RL组)、6%羟乙基淀粉130/0.4复苏组(HES组),按照Wiggers改良法复制失血性休克模型.于复苏后1 h、2 h4、h采用免疫组织化学的方法检测肺组织NF-κB的表达;光镜下观察肺组织形态学改变.结果 RL组与HES组肺组织NF-κB免疫组化染色细胞核阳性百分率较C组明显升高,RL组升高的程度较HES组明显(P〈0.01).免疫组化染色光镜观察显示:HES组比RL组的组织损伤明显减轻.结论 6%羟乙基淀粉130/0.4复苏失血性休克可以抑制肺组织NF-κB活性,减轻休克及复苏过程造成的肺损伤. 相似文献
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大豆皂苷不同提取方法比较研究 总被引:2,自引:0,他引:2
以大豆豆渣为原料,对大豆皂苷的提取分离方法进行研究。考察大孔树脂吸附法、有机溶剂提取方法、微波提取法及超声提取法对大豆皂苷提取率的影响,并对几种提取方法进行对比。结果表明,有机溶剂提取法的提取率最高,可达93.4%,但操作步骤较多,有机溶剂用量也相对较大,时间较长;大孔树脂吸附法的提取率也比较高,为90.2%,料液比较少,但提取时间却很长,需要6 h;而微波法和超声提取法则操作相对简单,时间短、温度低、提取速率快,其提取的提取率也比较理想,分别为59.8%和61.0%。 相似文献
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Recent events have renewed attention to how organizations rely on digital resources in response to exogenous shock. Though the literature on organizational resilience indicates that this is best understood as a process through which organizational actors respond to a specific shock, most IS research attends to resilience as an outcome. Against that backdrop, we present a case study of how a university shifted to virtual teaching in response to a government-imposed lockdown during the COVID-19 pandemic. Adopting a digital resourcing perspective allowed us to reveal the organizational resilience process and the way digital resources shaped it. We found that the resilience process unfolded in stages as educators, assisted by students, managers, and IT personnel pivoted, adapted, and normalized into teaching virtually. Across these stages, digital resources took on specific roles as the resilience process progressed from the organization’s pre-shock accumulation of digital resources into its continued digitalization efforts. Based on these findings, we contribute to existing literature by advancing and empirically substantiating a process view of the role of digital resources in organizational resilience. 相似文献
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在0.01g/mL碘化钾,0.016g/mL酒石酸钾钠,0.001g/mL抗坏血酸,0.24mol/L盐酸底液中,采用单扫描示波极谱法获得铅和碘络合物吸附波,用于皮蛋中微量铅的测量。文中讨论了碘化钾、酒石酸钾钠、抗坏血酸、盐酸的加入量及静止时间对反应的影响从而确定了适宜的实验条件。实验表明,铅在此底液中峰电位在-520mV,峰电流与铅离子的浓度在0.2~1.0μg/mL范围内呈良好的线性关系,线性回归方程为:Iy=2 492.2Cx+332.1,相关系数r2=0.999 4。回收率为98.4%~103.9%。此方法测定皮蛋中微量铅,仪器简单,操作快速、简便,准确度高,测定结果令人满意。 相似文献
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This paper investigates the views of 20 full-time international postgraduate students, many of whom were Chinese, on living, learning and becoming successful students at one university in a multicultural city in the Midlands of England. The qualitative study built on findings from the International Students’ Barometer (ISB) survey for the university, in that it seeks to understand how students’ experience of context (living) interacted with their experience of learning in building their identities as successful learners. Student participants were sampled opportunistically within a purposive framework. Data was collected through audio-recorded individual semi-structured interviews, using as a stimulus participant-constructed concept maps of their perceptions of learning in the university and living in the city. Interview data were transcribed and analysed thematically. The main findings showed that participants enjoyed living in a city with an international culture, although some found it strange initially because they encountered different styles of life and food, albeit including some that they enjoyed at home. They welcomed studying at a university with high international prestige, a wide range of excellent facilities and generally approachable tutors but were shocked by having to undertake unfamiliar styles of independent learning with brief teaching hours. They perceived culture shock as transitional, which declined as they made friends, often with co-linguists, and became familiar with life in the city, work in the university and the extensive support of tutors. 相似文献