Vanadium carbide is the most effective grain growth inhibitor for ultrafine WC-Co composites due to its high solubility and mobility in the cobalt phase at relatively low temperatures; however, there are still some de...Vanadium carbide is the most effective grain growth inhibitor for ultrafine WC-Co composites due to its high solubility and mobility in the cobalt phase at relatively low temperatures; however, there are still some debates over the best way to introduce it into the WC-Co formula- tion. In this paper, the differences between admixed and chemically doped grain growth inhibitors on the microstructural development and properties of an ultrafine WC-IOCo composite are discussed. The densification rate of chemically doped samples is slower in the early stage of sintering and the WC grain sizes of the sintered alloys are finer than those of admixed samples, leading to the increase of hardness and transverse rupture strength of the sintered alloys. The effectiveness of the chemically doped inhibitor is attributed to the formation of vana- dium rich layers on the surfaces of tungsten carbide powders during reduction and carbonization, which alters the surface and interface energies of WC grains, impedes the contact with each other of WC grains and contributes to the resistance to W diffusion across the layer during sintering, resulting in the inhibition of nanosized particle coalescence.展开更多
The phase evolution and magnetic properties of Nd9？xYxFe72Ti2Zr2B15 （x = 0,0.5,1,and 2） melt-spun nanocomposite ribbons were studied.It is found that Y addition not only enhances the formability of amorphous phase ...The phase evolution and magnetic properties of Nd9？xYxFe72Ti2Zr2B15 （x = 0,0.5,1,and 2） melt-spun nanocomposite ribbons were studied.It is found that Y addition not only enhances the formability of amorphous phase in the alloy,but also stabilizes the amorphous phase during the annealing treatment.The appropriate content of Y addition effectively enhances the remanence （Jr） of the annealed sample.The residual amorphous intergranular phase in the annealed sample optimizes the squareness of the loop,resulting in an larger maximum energy product （BH）max.The best magnetic properties,Jr = 0.78 T,Hci （coercivity） = 923.4 kA/m,and （BH）max = 98.5 kJ/m3,were obtained from the Nd8YFe72Ti2Zr2B15 ribbon spun at Vs = 4 m/s and annealed at 700°C for 10 min,which is composed of Nd2Fe14B,α-Fe,and amorphous phase.展开更多
随着全球气候变暖问题日益严峻,碳捕捉与封存(CO_(2) capture and storage,CCS)项目的产业化发展得到了各国政府的广泛关注。公平偏好的存在,使得参与者在做出决策时,不仅关乎自身的绝对收益,更加关注项目合作中利益分配的公平性。基于...随着全球气候变暖问题日益严峻,碳捕捉与封存(CO_(2) capture and storage,CCS)项目的产业化发展得到了各国政府的广泛关注。公平偏好的存在,使得参与者在做出决策时,不仅关乎自身的绝对收益,更加关注项目合作中利益分配的公平性。基于此,针对CCS产业化运营过程中能源企业存在的公平偏好和资金约束问题,本文构建了能源企业、CCS运营商和银行间的演化博弈模型,重点讨论了能源企业不同公平偏好类型对三方之间策略互动的影响及其敏感性分析。仿真结果表明:(1)在不存在公平偏好与存在竞争性偏好的情况下,均难以实现CCS产业化运营模式的有效推广,且竞争性偏好更不利于CCS产业化运营模式发展;(2)在存在社会福利偏好的情况下,较高的偏好系数才能推动CCS产业化运营模式进入帕累托状态,并且随着偏好系数的提升,促进效果更为显著;(3)银行和CCS运营商参与意愿的提高,均对CCS的产业化运营起到积极影响,其中前者的影响效果更为显著,且在社会福利偏好的影响下效果进一步放大;(4)能源企业较高的CCS技术合作运营成本对CCS项目的产业化发展存在负面影响,但社会福利偏好能提高能源企业对投资成本的承受意愿,从而降低这种负面影响。以上结论,可从公平偏好、金融机构和运营成本等角度为推动CCS产业化发展提供对策建议和理论指导。展开更多
文摘Vanadium carbide is the most effective grain growth inhibitor for ultrafine WC-Co composites due to its high solubility and mobility in the cobalt phase at relatively low temperatures; however, there are still some debates over the best way to introduce it into the WC-Co formula- tion. In this paper, the differences between admixed and chemically doped grain growth inhibitors on the microstructural development and properties of an ultrafine WC-IOCo composite are discussed. The densification rate of chemically doped samples is slower in the early stage of sintering and the WC grain sizes of the sintered alloys are finer than those of admixed samples, leading to the increase of hardness and transverse rupture strength of the sintered alloys. The effectiveness of the chemically doped inhibitor is attributed to the formation of vana- dium rich layers on the surfaces of tungsten carbide powders during reduction and carbonization, which alters the surface and interface energies of WC grains, impedes the contact with each other of WC grains and contributes to the resistance to W diffusion across the layer during sintering, resulting in the inhibition of nanosized particle coalescence.
文摘The phase evolution and magnetic properties of Nd9？xYxFe72Ti2Zr2B15 （x = 0,0.5,1,and 2） melt-spun nanocomposite ribbons were studied.It is found that Y addition not only enhances the formability of amorphous phase in the alloy,but also stabilizes the amorphous phase during the annealing treatment.The appropriate content of Y addition effectively enhances the remanence （Jr） of the annealed sample.The residual amorphous intergranular phase in the annealed sample optimizes the squareness of the loop,resulting in an larger maximum energy product （BH）max.The best magnetic properties,Jr = 0.78 T,Hci （coercivity） = 923.4 kA/m,and （BH）max = 98.5 kJ/m3,were obtained from the Nd8YFe72Ti2Zr2B15 ribbon spun at Vs = 4 m/s and annealed at 700°C for 10 min,which is composed of Nd2Fe14B,α-Fe,and amorphous phase.
文摘随着全球气候变暖问题日益严峻,碳捕捉与封存(CO_(2) capture and storage,CCS)项目的产业化发展得到了各国政府的广泛关注。公平偏好的存在,使得参与者在做出决策时,不仅关乎自身的绝对收益,更加关注项目合作中利益分配的公平性。基于此,针对CCS产业化运营过程中能源企业存在的公平偏好和资金约束问题,本文构建了能源企业、CCS运营商和银行间的演化博弈模型,重点讨论了能源企业不同公平偏好类型对三方之间策略互动的影响及其敏感性分析。仿真结果表明:(1)在不存在公平偏好与存在竞争性偏好的情况下,均难以实现CCS产业化运营模式的有效推广,且竞争性偏好更不利于CCS产业化运营模式发展;(2)在存在社会福利偏好的情况下,较高的偏好系数才能推动CCS产业化运营模式进入帕累托状态,并且随着偏好系数的提升,促进效果更为显著;(3)银行和CCS运营商参与意愿的提高,均对CCS的产业化运营起到积极影响,其中前者的影响效果更为显著,且在社会福利偏好的影响下效果进一步放大;(4)能源企业较高的CCS技术合作运营成本对CCS项目的产业化发展存在负面影响,但社会福利偏好能提高能源企业对投资成本的承受意愿,从而降低这种负面影响。以上结论,可从公平偏好、金融机构和运营成本等角度为推动CCS产业化发展提供对策建议和理论指导。
