The blowing and stirring composite process of molten iron desulfurization process affects the desulfurization efficiency and has obvious advantages in improving steel properties and expanding the scale of converter st...The blowing and stirring composite process of molten iron desulfurization process affects the desulfurization efficiency and has obvious advantages in improving steel properties and expanding the scale of converter steelmaking.At present,the injection position of the injection stirring research is fixed,and the desulfurization efficiency needs to be improved.The gas–liquid flow behavior of single-scale bubble model and the size and distribution of bubbles in multi-scale bubble model were studied by computational fluid dynamics numerical simulation method for the injection mixing composite process of jet inlet and stirring paddle rotating at the same speed.The pressure distribution and velocity distribution inside the fluid indicate that the velocity difference between the gas–liquid phases and the turbulence of the liquid are due to the collisions of bubbles,which are due to essential conditions for bubble breaking.Different injection air volumes have essential influence on the formation of single bubbles.When the injection volume reaches 2.8 m3/h,the turbulent kinetic energy is maximum,the bubble formation is rapid,and the desulfurization efficiency can be improved.The multi-bubble results show that the bubble diameter is mainly distributed in the range of 2–5 mm.The higher gas flow rate will increase the number of bubbles in the fluid and promote the bubble refinement process.展开更多
The gas–liquid flow behavior of the stirred flow field,the different positions of a single bubble,the initial velocity,the surface tension and the agglomeration of multiple bubbles were studied by CFD numerical simul...The gas–liquid flow behavior of the stirred flow field,the different positions of a single bubble,the initial velocity,the surface tension and the agglomeration of multiple bubbles were studied by CFD numerical simulation.The results show that the pressure distribution and velocity distribution inside the fluid during agitation indicate that the velocity difference between the liquid and the gas phase and the collision between the bubbles caused by the turbulent behavior of the liquid are the important conditions leading to the bubble breakage.Different initial bubble positions and initial bubble velocities have important effects on single bubble breakage.The surface tension is an important condition that affects the bubble breakage.When the surface tension coefficient is 0.7,the bubble will be stretched to the smallest degree;when the surface tension coefficient is 0.1,the bubble will be stretched to the largest degree and it will be easily broken into smaller bubbles.The multi-bubble results show the states and trajectories of coalescence between bubbles.The research results can provide data support for the engineering application of desulfurization process and theoretical guidance for the research of bubble breaking mechanism.展开更多
Seed germination is a crucial checkpoint for plant survival under unfavorable environmental conditions. Ab- scisic acid （ABA） signaling plays a vital role in integrating environmental information to regulate seed ge...Seed germination is a crucial checkpoint for plant survival under unfavorable environmental conditions. Ab- scisic acid （ABA） signaling plays a vital role in integrating environmental information to regulate seed germination. It has been well known that MCMI/AGAMOUS/DEFICIENS/SRF （MADS）-box transcription factors are key regulators of seed and flower development in Arabidopsis. However, little is known about their functions in seed germination. Here we report that MADS-box transcription factor AGL21 is a negative regulator of seed germination and post-germination growth by controlling the expression of ABA-INSENSITIVE 5 （ABIb＇） in Arabidopsis. The AGL21-overexpressing plants were hypersensitive to ABA, salt, and osmotic stresses during seed germination and early post-germination growth, whereas ag121 mutants were less sensitive. We found that AGL21 positively regulated ABI5 expression in seeds. Consistently, genetic analyses showed that AGL21 is epistatic to ABI5 in controlling seed germination. Chromatin immunoprecipitation assays further demonstrated that AGL21 could directly bind to the ABI5 promoter in plant cells. Moreover, we found that AGL21 responded to multiple environmental stresses and plant hormones during seed germination. Taken together, our results suggest that AGL21 acts as a surveillance integrator that incorporates environmental cues and endogenous hormonal signals into ABA signaling to regulate seed germination and early post-germination growth.展开更多
Crop yield plays a critical role in global food security.For optimal plant growth and maximal crop yields,nutrients must be balanced.However,the potential significance of balanced nitrogen-iron(N-Fe)for improving crop...Crop yield plays a critical role in global food security.For optimal plant growth and maximal crop yields,nutrients must be balanced.However,the potential significance of balanced nitrogen-iron(N-Fe)for improving crop yield and nitrogen use efficiency(NUE)has not previously been addressed.Here,we show that balanced N-Fe sufficiency significantly increases tiller number and boosts yield and NUE in rice and wheat.NIN-like protein 4(OsNLP4)plays a pivotal role in maintaining the N-Fe balance by coordinately regulating the expression of multiple genes involved in N and Fe metabolism and signaling.OsNLP4 also suppresses OsD3 expression and strigolactone(SL)signaling,thereby promoting tillering.Balanced N-Fe sufficiency promotes the nuclear localization of OsNLP4 by reducing H_(2)O_(2) levels,reinforcing the functions of OsNLP4.Interestingly,we found that OsNLP4 upregulates the expression of a set of H2O2-scavenging genes to promote its own accumulation in the nucleus.Furthermore,we demonstrated that foliar spraying of balanced N-Fe fertilizer at the tillering stage can effectively increase tiller number,yield,and NUE of both rice and wheat in the field.Collectively,these findings reveal the previously unrecognized effects of N-Fe balance on grain yield and NUE as well as the molecular mechanism by which the OsNLP4-OsD3 module integrates N-Fe nutrient signals to downregulate SL signaling and thereby promote rice tillering.Our study sheds light on how N-Fe nutrient signals modulate rice tillering and provide potential innovative approaches that improve crop yield with reduced N fertilizer input for benefitting sustainable agriculture worldwide.展开更多
After publication of our article,we detected a few errors in the figures.In Figure 1,we highlight the impact of N-Fe balance and OsNLP4 genotypes on grain yield and NUE;however,we mistakenly used an incorrect image in...After publication of our article,we detected a few errors in the figures.In Figure 1,we highlight the impact of N-Fe balance and OsNLP4 genotypes on grain yield and NUE;however,we mistakenly used an incorrect image in the far-left panel of Figure 1F and mistakenly omitted labels throughout Figure 1F.In Figure 3B,a scale bar was missing.In Figure 4L,HN-HFe was mislabeled as LH-HFe,and in Figure 4S,the lanes were not properly aligned.展开更多
基金supported by the National Natural Science Foundation of China(No.51904069)the Fundamental Research Funds for the Central Universities(No.N2223026)the Scientific Research Fund Project of Northeastern University at Qinhuangdao(No.XNY201808).
文摘The blowing and stirring composite process of molten iron desulfurization process affects the desulfurization efficiency and has obvious advantages in improving steel properties and expanding the scale of converter steelmaking.At present,the injection position of the injection stirring research is fixed,and the desulfurization efficiency needs to be improved.The gas–liquid flow behavior of single-scale bubble model and the size and distribution of bubbles in multi-scale bubble model were studied by computational fluid dynamics numerical simulation method for the injection mixing composite process of jet inlet and stirring paddle rotating at the same speed.The pressure distribution and velocity distribution inside the fluid indicate that the velocity difference between the gas–liquid phases and the turbulence of the liquid are due to the collisions of bubbles,which are due to essential conditions for bubble breaking.Different injection air volumes have essential influence on the formation of single bubbles.When the injection volume reaches 2.8 m3/h,the turbulent kinetic energy is maximum,the bubble formation is rapid,and the desulfurization efficiency can be improved.The multi-bubble results show that the bubble diameter is mainly distributed in the range of 2–5 mm.The higher gas flow rate will increase the number of bubbles in the fluid and promote the bubble refinement process.
基金supported by the National Natural Science Foundation of China(51904069)the Fundamental Research Funds for the Central Universities(N2223026)the Scientific Research Fund Project of Northeastern University at Qinhuangdao(XNY201808).
文摘The gas–liquid flow behavior of the stirred flow field,the different positions of a single bubble,the initial velocity,the surface tension and the agglomeration of multiple bubbles were studied by CFD numerical simulation.The results show that the pressure distribution and velocity distribution inside the fluid during agitation indicate that the velocity difference between the liquid and the gas phase and the collision between the bubbles caused by the turbulent behavior of the liquid are the important conditions leading to the bubble breakage.Different initial bubble positions and initial bubble velocities have important effects on single bubble breakage.The surface tension is an important condition that affects the bubble breakage.When the surface tension coefficient is 0.7,the bubble will be stretched to the smallest degree;when the surface tension coefficient is 0.1,the bubble will be stretched to the largest degree and it will be easily broken into smaller bubbles.The multi-bubble results show the states and trajectories of coalescence between bubbles.The research results can provide data support for the engineering application of desulfurization process and theoretical guidance for the research of bubble breaking mechanism.
基金This work was supported by the China National Natural Science Funds for Distinguished Young Scholar （grant no. 31500231 to L.-H.Yo）, China Postdoctoral Science Foundation, No.9 Special Fund （grant no. 2016T90577 to L.-H.Y.）, and Chinese Academy of Sciences （grant no. KSCX3-EW-N- 07 to C.-B.X.）.
文摘Seed germination is a crucial checkpoint for plant survival under unfavorable environmental conditions. Ab- scisic acid （ABA） signaling plays a vital role in integrating environmental information to regulate seed germination. It has been well known that MCMI/AGAMOUS/DEFICIENS/SRF （MADS）-box transcription factors are key regulators of seed and flower development in Arabidopsis. However, little is known about their functions in seed germination. Here we report that MADS-box transcription factor AGL21 is a negative regulator of seed germination and post-germination growth by controlling the expression of ABA-INSENSITIVE 5 （ABIb＇） in Arabidopsis. The AGL21-overexpressing plants were hypersensitive to ABA, salt, and osmotic stresses during seed germination and early post-germination growth, whereas ag121 mutants were less sensitive. We found that AGL21 positively regulated ABI5 expression in seeds. Consistently, genetic analyses showed that AGL21 is epistatic to ABI5 in controlling seed germination. Chromatin immunoprecipitation assays further demonstrated that AGL21 could directly bind to the ABI5 promoter in plant cells. Moreover, we found that AGL21 responded to multiple environmental stresses and plant hormones during seed germination. Taken together, our results suggest that AGL21 acts as a surveillance integrator that incorporates environmental cues and endogenous hormonal signals into ABA signaling to regulate seed germination and early post-germination growth.
基金supported by grants from the National Natural Science Foundation of China(grant no.32321001 to C.B.X.and 32100208 to J.W.)the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDA24010303)+1 种基金the Anhui Provincial Natural Science Foundation(grant no.2108085QC103)the Fundamental Research Funds for the Central Universities(grant no.WK9100000023).
文摘Crop yield plays a critical role in global food security.For optimal plant growth and maximal crop yields,nutrients must be balanced.However,the potential significance of balanced nitrogen-iron(N-Fe)for improving crop yield and nitrogen use efficiency(NUE)has not previously been addressed.Here,we show that balanced N-Fe sufficiency significantly increases tiller number and boosts yield and NUE in rice and wheat.NIN-like protein 4(OsNLP4)plays a pivotal role in maintaining the N-Fe balance by coordinately regulating the expression of multiple genes involved in N and Fe metabolism and signaling.OsNLP4 also suppresses OsD3 expression and strigolactone(SL)signaling,thereby promoting tillering.Balanced N-Fe sufficiency promotes the nuclear localization of OsNLP4 by reducing H_(2)O_(2) levels,reinforcing the functions of OsNLP4.Interestingly,we found that OsNLP4 upregulates the expression of a set of H2O2-scavenging genes to promote its own accumulation in the nucleus.Furthermore,we demonstrated that foliar spraying of balanced N-Fe fertilizer at the tillering stage can effectively increase tiller number,yield,and NUE of both rice and wheat in the field.Collectively,these findings reveal the previously unrecognized effects of N-Fe balance on grain yield and NUE as well as the molecular mechanism by which the OsNLP4-OsD3 module integrates N-Fe nutrient signals to downregulate SL signaling and thereby promote rice tillering.Our study sheds light on how N-Fe nutrient signals modulate rice tillering and provide potential innovative approaches that improve crop yield with reduced N fertilizer input for benefitting sustainable agriculture worldwide.
文摘After publication of our article,we detected a few errors in the figures.In Figure 1,we highlight the impact of N-Fe balance and OsNLP4 genotypes on grain yield and NUE;however,we mistakenly used an incorrect image in the far-left panel of Figure 1F and mistakenly omitted labels throughout Figure 1F.In Figure 3B,a scale bar was missing.In Figure 4L,HN-HFe was mislabeled as LH-HFe,and in Figure 4S,the lanes were not properly aligned.
