Cacao (Theobroma cacao L.) is of significant economic importance in several tropical countries but its yield potentials are low mainly because of poor soil fertility especially low levels of potassium (K). Cacao has a...Cacao (Theobroma cacao L.) is of significant economic importance in several tropical countries but its yield potentials are low mainly because of poor soil fertility especially low levels of potassium (K). Cacao has a high demand for K to maintain healthy growth and production. Knowledge of K use in cacao will help the development of suitable crop management practices and will aid breeding varieties adapted to environments with a limited soil K supply. Using a plant growth chamber, we investigated the growth and physiological traits among three cacao varieties at three levels of growth medium K (52, 156, and 469 mg·plant-1). Significant K effects were observed on growth traits including stem diameter, root length, chlorophyll b, and the ratio of chlorophyll a/b. Significant K effect was also found on carbohydrate metabolites, such as fructose, glucose, myo-inositol, raffinose and starch. However, no K effect was observed in other growth and physiological indicators, including biomass of seedling and net photosynthetic rate. There were significant genotype differences on seedling growth indicators, including stem diameter, stem height, total biomass, leaf biomass, leaf area, root length, chlorophyll a + b and carotenoids. Genotype difference was also found on all measured carbohydrate and starch metabolites, except maltose and raffinose. Results of this study indicate that although K plays a critical role in cacao tree growth and productivity, cacao may be less sensitive to K deficiency during the seedling stage. The present results improved our understanding about K and plants interaction in cacao seedlings, which is useful for crop management and germplasm utilization.展开更多
In this work,the novel Ni-based superalloy GH4065A inertia friction welding(IFW)joints were subjected to the post-welding heat treatments(PWHT)at 730℃for 5 h or 760℃for 5 h,and the differences in microstructure char...In this work,the novel Ni-based superalloy GH4065A inertia friction welding(IFW)joints were subjected to the post-welding heat treatments(PWHT)at 730℃for 5 h or 760℃for 5 h,and the differences in microstructure characteristics,local mechanical properties,and fatigue failure life were focused.Furthermore,based on the high-temperature low-cycle fatigue testing and characterization results,the correlation between the microstructure characteristics and low-cycle fatigue damage behavior was systematically analyzed.It was found that there were smaller grains in the thermo-mechanically affected zone(TMAZ)than in the weld zone and heat-affected zone(HAZ),and the boundary region between TMAZ and HAZ was the fatigue failure position of IFW joints under the high-temperature low-cycle fatigue loading.The fatigue testing results showed that the high-temperature fatigue performance for GH4065A IFW joints degenerated with the increase in PWHT temperature.There existed cyclic softening and inhomogeneous fatigue damage in an IFW joint,which was more significant under the 760℃5 h PWHT condition.Microstructurally,dislocation tangles and cells formed in the boundary region between TMAZ and HAZ under the fatigue loading.The difference in grain size after the IFW process and the inhomogeneousγ′phrase re-precipitation after the PWHT in the boundary region between TMAZ and HAZ resulted in the local inhomogeneous strengthening,corresponding to uneven plastic deformation and fatigue failure behavior under the fatigue loadings.展开更多
In recent years,optical phased arrays(OPAs)have attracted great interest for their potential applications in light detection and ranging(Li DAR),free-space optical communications(FSOs),holography,and so on.Photonic in...In recent years,optical phased arrays(OPAs)have attracted great interest for their potential applications in light detection and ranging(Li DAR),free-space optical communications(FSOs),holography,and so on.Photonic integrated circuits(PICs)provide solutions for further reducing the size,weight,power,and cost of OPAs.In this paper,we review the recent development of photonic integrated OPAs.We summarize the typical architecture of the integrated OPAs and their performance.We analyze the key components of OPAs and evaluate the figure of merit for OPAs.Various applications in Li DAR,FSO,imaging,biomedical sensing,and specialized beam generation are introduced.展开更多
文摘Cacao (Theobroma cacao L.) is of significant economic importance in several tropical countries but its yield potentials are low mainly because of poor soil fertility especially low levels of potassium (K). Cacao has a high demand for K to maintain healthy growth and production. Knowledge of K use in cacao will help the development of suitable crop management practices and will aid breeding varieties adapted to environments with a limited soil K supply. Using a plant growth chamber, we investigated the growth and physiological traits among three cacao varieties at three levels of growth medium K (52, 156, and 469 mg·plant-1). Significant K effects were observed on growth traits including stem diameter, root length, chlorophyll b, and the ratio of chlorophyll a/b. Significant K effect was also found on carbohydrate metabolites, such as fructose, glucose, myo-inositol, raffinose and starch. However, no K effect was observed in other growth and physiological indicators, including biomass of seedling and net photosynthetic rate. There were significant genotype differences on seedling growth indicators, including stem diameter, stem height, total biomass, leaf biomass, leaf area, root length, chlorophyll a + b and carotenoids. Genotype difference was also found on all measured carbohydrate and starch metabolites, except maltose and raffinose. Results of this study indicate that although K plays a critical role in cacao tree growth and productivity, cacao may be less sensitive to K deficiency during the seedling stage. The present results improved our understanding about K and plants interaction in cacao seedlings, which is useful for crop management and germplasm utilization.
基金supported by the National Natural Science Foundation of China(Grant Nos.52322408,52305407)the Science and Technology Program of Tianjin(23JCQNJC01990)the independent Innovation Fund of Tianjin University(2024XQM-0013).
文摘In this work,the novel Ni-based superalloy GH4065A inertia friction welding(IFW)joints were subjected to the post-welding heat treatments(PWHT)at 730℃for 5 h or 760℃for 5 h,and the differences in microstructure characteristics,local mechanical properties,and fatigue failure life were focused.Furthermore,based on the high-temperature low-cycle fatigue testing and characterization results,the correlation between the microstructure characteristics and low-cycle fatigue damage behavior was systematically analyzed.It was found that there were smaller grains in the thermo-mechanically affected zone(TMAZ)than in the weld zone and heat-affected zone(HAZ),and the boundary region between TMAZ and HAZ was the fatigue failure position of IFW joints under the high-temperature low-cycle fatigue loading.The fatigue testing results showed that the high-temperature fatigue performance for GH4065A IFW joints degenerated with the increase in PWHT temperature.There existed cyclic softening and inhomogeneous fatigue damage in an IFW joint,which was more significant under the 760℃5 h PWHT condition.Microstructurally,dislocation tangles and cells formed in the boundary region between TMAZ and HAZ under the fatigue loading.The difference in grain size after the IFW process and the inhomogeneousγ′phrase re-precipitation after the PWHT in the boundary region between TMAZ and HAZ resulted in the local inhomogeneous strengthening,corresponding to uneven plastic deformation and fatigue failure behavior under the fatigue loadings.
基金supported by the Key Research and Development Program of Hubei Province(No.2021BAA004)the Innovation Project of Optics Valley Laboratory(Nos.OVL2021BG004 and OVL2023ZD004)+1 种基金the National Natural Science Foundation of China(NSFC)(Nos.62125503,62261160388,and 62105115)the Natural Science Foundation of Hubei Province of China(No.2023AFA028)。
文摘In recent years,optical phased arrays(OPAs)have attracted great interest for their potential applications in light detection and ranging(Li DAR),free-space optical communications(FSOs),holography,and so on.Photonic integrated circuits(PICs)provide solutions for further reducing the size,weight,power,and cost of OPAs.In this paper,we review the recent development of photonic integrated OPAs.We summarize the typical architecture of the integrated OPAs and their performance.We analyze the key components of OPAs and evaluate the figure of merit for OPAs.Various applications in Li DAR,FSO,imaging,biomedical sensing,and specialized beam generation are introduced.
