为明确品种抗性和杀菌剂对赤霉病发生及呕吐毒素积累的影响,2022年对8个不同抗性小麦品种和4种杀菌剂防治赤霉病和呕吐毒素进行防效评价。结果表明:在4月10日(扬花株率5%左右)和4月17日2次施药后,200 g/L氟唑菌酰羟胺SC 50 m L/667 m^(2...为明确品种抗性和杀菌剂对赤霉病发生及呕吐毒素积累的影响,2022年对8个不同抗性小麦品种和4种杀菌剂防治赤霉病和呕吐毒素进行防效评价。结果表明:在4月10日(扬花株率5%左右)和4月17日2次施药后,200 g/L氟唑菌酰羟胺SC 50 m L/667 m^(2)+25%丙环唑SC 30 m L/667 m^(2)、40%丙硫菌唑·戊唑醇SC 40 m L/667 m^(2)对赤霉病的防效均在95%左右,25%吡唑醚菌酯SC40 m L/667 m^(2)+27%戊唑·噻霉酮EW 35 m L/667 m^(2)对赤霉病的防效在91%左右,480 g/L氰烯·戊唑醇SC 50 m L/667 m^(2)对赤霉病的防效在84%左右;清水对照区的赤霉病自然发生程度、DON含量及药剂处理区的赤霉病发生程度呈现中感品种>中抗品种>抗性品种趋势。品种抗性和杀菌剂在防治赤霉病过程中存在交互作用,效应量依次为药剂>品种×药剂>品种。结论:利用品种抗性和杀菌剂能够有效控制赤霉病,其协同防效随品种抗性增强而提高;在小麦扬花初期施用氟唑菌酰羟胺、丙硫菌唑、氰烯菌酯等,即使扬花期遇连阴雨天气,可在第1次施药后间隔6~7 d再次施药,也能够保证防效。展开更多
In piezoceramic ultrasonic devices,the piezoceramic stacks may fail permanently or function improperly if their working temperatures overstep the Curie temperature of the piezoceramic material.While the end of the hor...In piezoceramic ultrasonic devices,the piezoceramic stacks may fail permanently or function improperly if their working temperatures overstep the Curie temperature of the piezoceramic material.While the end of the horn usually serves near the melting point of the molten metal and is enclosed in an airtight chamber,so that it is difficult to experimentally measure the temperature of the transducer and its variation with time,which bring heavy difficulty to the design of the ultrasonic molten metal treatment system.To find a way out,conjugate heat transfer analysis of an ultrasonic molten metal treatment system is performed with coupled fluid and heat transfer finite element method.In modeling of the system,the RNG model and the SIMPLE algorithm are adopted for turbulence and nonlinear coupling between the momentum equation and the energy equation.Forced air cooling as well as natural air cooling is analyzed to compare the difference of temperature evolution.Numerical results show that,after about 350 s of working time,temperatures in the surface of the ceramic stacks in forced air cooling drop about 7 K compared with that in natural cooling.At 240 s,The molten metal surface emits heat radiation with a maximum rate of about 19 036 W/m2,while the heat insulation disc absorbs heat radiation at a maximum rate of about 7922 W/m2,which indicates the effectiveness of heat insulation of the asbestos pad.Transient heat transfer film coefficient and its distribution,which are difficult to be measured experimentally are also obtained through numerical simulation.At 240 s,the heat transfer film coefficient in the surface of the transducer ranges from–17.86 to 20.17 W/（m2？K）.Compared with the trial and error method based on the test,the proposed research provides a more effective way in the design and analysis of the temperature control of the molten metal treatment system.展开更多
文摘为明确品种抗性和杀菌剂对赤霉病发生及呕吐毒素积累的影响,2022年对8个不同抗性小麦品种和4种杀菌剂防治赤霉病和呕吐毒素进行防效评价。结果表明:在4月10日(扬花株率5%左右)和4月17日2次施药后,200 g/L氟唑菌酰羟胺SC 50 m L/667 m^(2)+25%丙环唑SC 30 m L/667 m^(2)、40%丙硫菌唑·戊唑醇SC 40 m L/667 m^(2)对赤霉病的防效均在95%左右,25%吡唑醚菌酯SC40 m L/667 m^(2)+27%戊唑·噻霉酮EW 35 m L/667 m^(2)对赤霉病的防效在91%左右,480 g/L氰烯·戊唑醇SC 50 m L/667 m^(2)对赤霉病的防效在84%左右;清水对照区的赤霉病自然发生程度、DON含量及药剂处理区的赤霉病发生程度呈现中感品种>中抗品种>抗性品种趋势。品种抗性和杀菌剂在防治赤霉病过程中存在交互作用,效应量依次为药剂>品种×药剂>品种。结论:利用品种抗性和杀菌剂能够有效控制赤霉病,其协同防效随品种抗性增强而提高;在小麦扬花初期施用氟唑菌酰羟胺、丙硫菌唑、氰烯菌酯等,即使扬花期遇连阴雨天气,可在第1次施药后间隔6~7 d再次施药,也能够保证防效。
基金Supported by Beijing Municipal Natural Science Foundation of China(Grant No.3093027)
文摘In piezoceramic ultrasonic devices,the piezoceramic stacks may fail permanently or function improperly if their working temperatures overstep the Curie temperature of the piezoceramic material.While the end of the horn usually serves near the melting point of the molten metal and is enclosed in an airtight chamber,so that it is difficult to experimentally measure the temperature of the transducer and its variation with time,which bring heavy difficulty to the design of the ultrasonic molten metal treatment system.To find a way out,conjugate heat transfer analysis of an ultrasonic molten metal treatment system is performed with coupled fluid and heat transfer finite element method.In modeling of the system,the RNG model and the SIMPLE algorithm are adopted for turbulence and nonlinear coupling between the momentum equation and the energy equation.Forced air cooling as well as natural air cooling is analyzed to compare the difference of temperature evolution.Numerical results show that,after about 350 s of working time,temperatures in the surface of the ceramic stacks in forced air cooling drop about 7 K compared with that in natural cooling.At 240 s,The molten metal surface emits heat radiation with a maximum rate of about 19 036 W/m2,while the heat insulation disc absorbs heat radiation at a maximum rate of about 7922 W/m2,which indicates the effectiveness of heat insulation of the asbestos pad.Transient heat transfer film coefficient and its distribution,which are difficult to be measured experimentally are also obtained through numerical simulation.At 240 s,the heat transfer film coefficient in the surface of the transducer ranges from–17.86 to 20.17 W/（m2？K）.Compared with the trial and error method based on the test,the proposed research provides a more effective way in the design and analysis of the temperature control of the molten metal treatment system.
