为了全面掌握不同热解条件下玉米芯的热解特性及热解过程中气相产物随温度变化的释放规律,深刻理解玉米芯的热解行为及反应机理,该文采用热重-质谱联用技术对玉米芯进行了氮气气氛下的热解特性试验研究,对比研究了不同升温速率（5、10...为了全面掌握不同热解条件下玉米芯的热解特性及热解过程中气相产物随温度变化的释放规律,深刻理解玉米芯的热解行为及反应机理,该文采用热重-质谱联用技术对玉米芯进行了氮气气氛下的热解特性试验研究,对比研究了不同升温速率（5、10、20℃/min）、不同粒度（74、154、280、450μm）、不同气体流速（30、60、90 m L/min）等因素对玉米芯热解行为的影响,发现非等温失重过程可分为4个阶段：失水、预热解过渡、挥发分析出和炭化阶段。通过质谱分析研究了热解过程小分子气相产物（CO、CO2、CH4、O2、H2、H2O）的释放规律,并计算了挥发分释放指数。升温速率升高,热解反应越易进行;在粒度小于450μm范围内,试样热解的总失重率随粒度的增大而增加,而且颗粒越大,挥发分产物开始逸出的温度越低。粒度为〉154-450μm的试样的热解过程主要受颗粒内部热传递影响,而粒度〈154μm的试样的热解主要受内在反应动力学速率控制;随着气体流速升高,试样热解的总失重率和初始温度增大,但增幅很小,最大失重速率对应的温度也有向高温段移动的趋势。利用Coats-Redfern方法计算出玉米芯的热解动力学参数,说明玉米芯热解的挥发分析出阶段可用单段一级反应描述。该研究对于优化以玉米芯为原料的热化学转化工艺参数和提高燃料产物的产量与品质等具有重要意义,对于设计和开发高效的生物质能转化设备也可提供参考。展开更多
Saflufenacil is a new herbicide for use in field maize (Zea mays L.) and other crops that may have potential for weed management in sweet maize. Tolerance of eight sweet maize hybrids to saflufenacil and saflufenacil ...Saflufenacil is a new herbicide for use in field maize (Zea mays L.) and other crops that may have potential for weed management in sweet maize. Tolerance of eight sweet maize hybrids to saflufenacil and saflufenacil plus dimethenamid-p applied preemergence (PRE) were studied at two Ontario locations in 2008 and 2009. Saflufenacil applied PRE at 75 and 150 g·ha–1 and saflufenacil plus dimethenamid-p (pre-mixed) applied PRE at 735 and 1470 g·ha–1 caused minimal (less than 5%) injury in Cahill, GH4927, Harvest Gold, Rocker, BSS5362, GG236, GG447, and GG763 sweet maize hybrids at 1 and 2 weeks after emergence (WAE). Saflufenacil or saflufenacil plus dimethenamid-p applied PRE did not reduce plant height, cob size, or yield of any of the sweet maize hybrids tested in this study. Based on these results, saflufenacil and saflufenacil plus dimethenamid-p pre-mixed applied PRE at the doses evaluated can be safely used for weed management in Cahill, GH4927, Harvest Gold, Rocker, BSS5362, GG236, GG447, and GG763 sweet maize under Ontario environmental conditions.展开更多
文摘为了全面掌握不同热解条件下玉米芯的热解特性及热解过程中气相产物随温度变化的释放规律,深刻理解玉米芯的热解行为及反应机理,该文采用热重-质谱联用技术对玉米芯进行了氮气气氛下的热解特性试验研究,对比研究了不同升温速率（5、10、20℃/min）、不同粒度（74、154、280、450μm）、不同气体流速（30、60、90 m L/min）等因素对玉米芯热解行为的影响,发现非等温失重过程可分为4个阶段：失水、预热解过渡、挥发分析出和炭化阶段。通过质谱分析研究了热解过程小分子气相产物（CO、CO2、CH4、O2、H2、H2O）的释放规律,并计算了挥发分释放指数。升温速率升高,热解反应越易进行;在粒度小于450μm范围内,试样热解的总失重率随粒度的增大而增加,而且颗粒越大,挥发分产物开始逸出的温度越低。粒度为〉154-450μm的试样的热解过程主要受颗粒内部热传递影响,而粒度〈154μm的试样的热解主要受内在反应动力学速率控制;随着气体流速升高,试样热解的总失重率和初始温度增大,但增幅很小,最大失重速率对应的温度也有向高温段移动的趋势。利用Coats-Redfern方法计算出玉米芯的热解动力学参数,说明玉米芯热解的挥发分析出阶段可用单段一级反应描述。该研究对于优化以玉米芯为原料的热化学转化工艺参数和提高燃料产物的产量与品质等具有重要意义,对于设计和开发高效的生物质能转化设备也可提供参考。
文摘Saflufenacil is a new herbicide for use in field maize (Zea mays L.) and other crops that may have potential for weed management in sweet maize. Tolerance of eight sweet maize hybrids to saflufenacil and saflufenacil plus dimethenamid-p applied preemergence (PRE) were studied at two Ontario locations in 2008 and 2009. Saflufenacil applied PRE at 75 and 150 g·ha–1 and saflufenacil plus dimethenamid-p (pre-mixed) applied PRE at 735 and 1470 g·ha–1 caused minimal (less than 5%) injury in Cahill, GH4927, Harvest Gold, Rocker, BSS5362, GG236, GG447, and GG763 sweet maize hybrids at 1 and 2 weeks after emergence (WAE). Saflufenacil or saflufenacil plus dimethenamid-p applied PRE did not reduce plant height, cob size, or yield of any of the sweet maize hybrids tested in this study. Based on these results, saflufenacil and saflufenacil plus dimethenamid-p pre-mixed applied PRE at the doses evaluated can be safely used for weed management in Cahill, GH4927, Harvest Gold, Rocker, BSS5362, GG236, GG447, and GG763 sweet maize under Ontario environmental conditions.
