Konosirus punctatus is an economically important marine fishery resource and is widely distributed from the Indian to Pacific oceans.It is a good non-model species for genetic studies on salinity and temperature adapt...Konosirus punctatus is an economically important marine fishery resource and is widely distributed from the Indian to Pacific oceans.It is a good non-model species for genetic studies on salinity and temperature adaptation.However,a high-quality reference genome has not yet been reported.展开更多
Low strength and poor corrosion resistance are two long-standing bottlenecks with dilute Mg alloys.Here,we report that the corrosion resistance of Mg-0.6Al-0.5Mn-0.2Ca(wt.%)alloy sheet can be significantly improved by...Low strength and poor corrosion resistance are two long-standing bottlenecks with dilute Mg alloys.Here,we report that the corrosion resistance of Mg-0.6Al-0.5Mn-0.2Ca(wt.%)alloy sheet can be significantly improved by micro-alloying with 0.3 wt.%Ce,and the strength can be considerably augmented after aging treatment.Simultaneous optimization of strength,ductility,and corrosion resistance is difficult due to the inherent trade-off in Mg alloys.Surprisingly,our aged Mg-0.6Al-0.5Mn-0.2Ca-0.3Ce alloy features with yield strength(YS)of∼194 MPa,ultimate tensile strength(UTS)of∼265 MPa,elongation to failure(EF)of∼17.2%,and corrosion rate(CR)of 2.2 mm y^(−1),the combination of which exhibits competitive advantage over other comparative dilute Mg alloys.It is found that Ce addition decreases the activity of cathodic phases,inhibits detrimental effects of Fe impurities,and forms a protective Ce-containing surface film.The high strength stems from the precipitation of ordered Guinier-Preston(G.P.)zones dispersed in uniform fine grains with an average grain size of∼8.2μm.The atomic-scale G.P.zones result in a noticeable age hardening response but do not act as crack initiation and propagation site,so our alloy also performs satisfactory ductility.This work sheds light on the design and fabrication of strong,ductile,and corrosion-resistant dilute magnesium alloys to be used in electronic products and automotive bodies.展开更多
The collision probability computation of space objects plays an important role in space situational awareness,particularly for conjunction assessment and collision avoidance.Early works mainly relied on Monte Carlo si...The collision probability computation of space objects plays an important role in space situational awareness,particularly for conjunction assessment and collision avoidance.Early works mainly relied on Monte Carlo simulations to predict collision probabilities.Although such simulations are accurate when a large number of samples are used,these methods are perceived as computationally intensive,which limits their application in practice.To overcome this limitation,many approximation methods have been developed over the past three decades.This paper presents a comprehensive review of existing space-object collision probability computation methods.The advantages and limitations of different methods are analyzed and a systematic comparison is presented.Advice regarding how to select a suitable method for different short-term encounter scenarios is then provided.Additionally,potential future research avenues are discussed.展开更多
Quantum dots(QDs) can achieve high quantum yields close to unity in liquid solutions, whereas they exhibit a decreased conversion efficiency after being integrated into solid-state polymer matrices for light-emitting ...Quantum dots(QDs) can achieve high quantum yields close to unity in liquid solutions, whereas they exhibit a decreased conversion efficiency after being integrated into solid-state polymer matrices for light-emitting diode(LED) devices, which is called the host matrix effect. In this study, we propose a solid–liquid hybrid-state QD-LED to solve this issue. The ethylene-terminated polydimethylsiloxane (ethylene-PDMS) is used to establish a solid-state cross-linked network, whereas the methyl-terminated PDMS (methyl-PDMS) is used in its liquid state. From a macroscopic level, the cured solid–liquid hybrid-state PDMS (SLHP) composites reach a solid state,which is stable and flexible enough to be used in LED devices. Compared with LEDs using conventional QD/solid PDMS composites at equal color conversion efficiency ranging from 40% to 60%, the luminous flux of LEDs with QD/SLHP composites is increased by 13.0% using an optimized methyl-PDMS concentration of 85 wt. %.As a result, high efficiency QD-LEDs using QDs as the only color convertor with luminous efficacy of 89.6 lm/W (0.19 A) were achieved, which show a working stability comparable with that using conventional solid-state structures at a harsh condition. Consequently, the novel approach shows great potential for achieving high efficiency and high stability QD-LEDs, which is also compatible with current structures used in illumination and display applications.展开更多
A numerical model is proposed for analyzing the effects of added mass and damping on the dynamic behaviors of hydrofoils.Strongly coupled fluid-structure interactions(FSIs)of hydrofoils are analyzed by using the 3-D p...A numerical model is proposed for analyzing the effects of added mass and damping on the dynamic behaviors of hydrofoils.Strongly coupled fluid-structure interactions(FSIs)of hydrofoils are analyzed by using the 3-D panel method for the fluid and the finite element method for the hydrofoils.The added mass and damping matrices due to the external fluid of the hydrofoil are asymmetric and computational inefficient.The computational inefficiencies associated with these asymmetric matrices are overcome by using a modal reduction technique,in which the first several wet mode vectors of the hydrofoil are employed in the analysis of the FSI problem.The discretized system of equations of motion for the hydrofoil are solved using the Wilson-6 method.The present methods are validated by comparing the computed results with those obtained from the finite element analysis.It is found that the stationary flow is sufficient for determining the wet modes of the hydrofoil under the condition of single-phase potential flow and without phase change.In the case of relatively large inflow velocity,the added damping of the fluid can significantly affect the structural responses of the hydrofoil.展开更多
基金supported by the National Natural Science Foundation of China(41806156)Zhejiang Provincial Natural Science Foundation of China(LY20C190008,LY22D060001,Y22D064798)+3 种基金Science and Technology Project of Zhoushan(2020C21016)Fund of Guangdong Provincial Key Laboratory of Fishery Ecology and Environment(FEEL-2021-8)Open Foundation from Key Laboratory of Tropical Marine Bio-Resources and Ecology,Chinese Academy of Sciences(LMB20201005)Open Foundation from Marine Sciences in the First-Class Subjects of Zhejiang(20200201,20200202)。
文摘Konosirus punctatus is an economically important marine fishery resource and is widely distributed from the Indian to Pacific oceans.It is a good non-model species for genetic studies on salinity and temperature adaptation.However,a high-quality reference genome has not yet been reported.
基金the National Natural Science Foundation of China(Nos.U19A2084,U22A20109,and 52104376)the China Postdoctoral Science Foundation(Nos.2021T140250 and 2021M701376)Partial financial support came from the Science and Technology Development Program of Jilin Province(Nos.20200201002JC and 20200401025GX).
文摘Low strength and poor corrosion resistance are two long-standing bottlenecks with dilute Mg alloys.Here,we report that the corrosion resistance of Mg-0.6Al-0.5Mn-0.2Ca(wt.%)alloy sheet can be significantly improved by micro-alloying with 0.3 wt.%Ce,and the strength can be considerably augmented after aging treatment.Simultaneous optimization of strength,ductility,and corrosion resistance is difficult due to the inherent trade-off in Mg alloys.Surprisingly,our aged Mg-0.6Al-0.5Mn-0.2Ca-0.3Ce alloy features with yield strength(YS)of∼194 MPa,ultimate tensile strength(UTS)of∼265 MPa,elongation to failure(EF)of∼17.2%,and corrosion rate(CR)of 2.2 mm y^(−1),the combination of which exhibits competitive advantage over other comparative dilute Mg alloys.It is found that Ce addition decreases the activity of cathodic phases,inhibits detrimental effects of Fe impurities,and forms a protective Ce-containing surface film.The high strength stems from the precipitation of ordered Guinier-Preston(G.P.)zones dispersed in uniform fine grains with an average grain size of∼8.2μm.The atomic-scale G.P.zones result in a noticeable age hardening response but do not act as crack initiation and propagation site,so our alloy also performs satisfactory ductility.This work sheds light on the design and fabrication of strong,ductile,and corrosion-resistant dilute magnesium alloys to be used in electronic products and automotive bodies.
基金The authors acknowledge financial support from the National Natural Science Foundation of China(Nos.11902347 and 11972044).
文摘The collision probability computation of space objects plays an important role in space situational awareness,particularly for conjunction assessment and collision avoidance.Early works mainly relied on Monte Carlo simulations to predict collision probabilities.Although such simulations are accurate when a large number of samples are used,these methods are perceived as computationally intensive,which limits their application in practice.To overcome this limitation,many approximation methods have been developed over the past three decades.This paper presents a comprehensive review of existing space-object collision probability computation methods.The advantages and limitations of different methods are analyzed and a systematic comparison is presented.Advice regarding how to select a suitable method for different short-term encounter scenarios is then provided.Additionally,potential future research avenues are discussed.
基金National Natural Science Foundation of China(NSFC)(51735004,51775199)Natural Science Foundation of Guangdong Province(2014A030312017)Science Technology Program of Guangdong Province(2016B010130001)
文摘Quantum dots(QDs) can achieve high quantum yields close to unity in liquid solutions, whereas they exhibit a decreased conversion efficiency after being integrated into solid-state polymer matrices for light-emitting diode(LED) devices, which is called the host matrix effect. In this study, we propose a solid–liquid hybrid-state QD-LED to solve this issue. The ethylene-terminated polydimethylsiloxane (ethylene-PDMS) is used to establish a solid-state cross-linked network, whereas the methyl-terminated PDMS (methyl-PDMS) is used in its liquid state. From a macroscopic level, the cured solid–liquid hybrid-state PDMS (SLHP) composites reach a solid state,which is stable and flexible enough to be used in LED devices. Compared with LEDs using conventional QD/solid PDMS composites at equal color conversion efficiency ranging from 40% to 60%, the luminous flux of LEDs with QD/SLHP composites is increased by 13.0% using an optimized methyl-PDMS concentration of 85 wt. %.As a result, high efficiency QD-LEDs using QDs as the only color convertor with luminous efficacy of 89.6 lm/W (0.19 A) were achieved, which show a working stability comparable with that using conventional solid-state structures at a harsh condition. Consequently, the novel approach shows great potential for achieving high efficiency and high stability QD-LEDs, which is also compatible with current structures used in illumination and display applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.52001130,11922208, 51839005)supported by the Scientific Research Foundation from Huazhong University of Science and Technology(Grant No.2019kfyXJJS005).
文摘A numerical model is proposed for analyzing the effects of added mass and damping on the dynamic behaviors of hydrofoils.Strongly coupled fluid-structure interactions(FSIs)of hydrofoils are analyzed by using the 3-D panel method for the fluid and the finite element method for the hydrofoils.The added mass and damping matrices due to the external fluid of the hydrofoil are asymmetric and computational inefficient.The computational inefficiencies associated with these asymmetric matrices are overcome by using a modal reduction technique,in which the first several wet mode vectors of the hydrofoil are employed in the analysis of the FSI problem.The discretized system of equations of motion for the hydrofoil are solved using the Wilson-6 method.The present methods are validated by comparing the computed results with those obtained from the finite element analysis.It is found that the stationary flow is sufficient for determining the wet modes of the hydrofoil under the condition of single-phase potential flow and without phase change.In the case of relatively large inflow velocity,the added damping of the fluid can significantly affect the structural responses of the hydrofoil.