Results 11 to 20 of about 7,074 (108)

The Dependence of Properties on Structural Features in Macro/Micro Levels for PBF‐LB Fabricated Porous NiTi Alloy

open access: yesRare Metals, EarlyView.
ABSTRACT Porous NiTi alloys are widely used in biomedical and engineering fields. Using the PBF‐LB technique, the TPMS and Voronoi porous parts with a porosity of ∼67% and a minimum feature size of 0.15 ± 0.02 mm were fabricated. Although the bulk sample fabricated with the same parameters is defect‐free, μ‐CT reconstruction on the porous sample ...
Wen‐Hao Zeng   +7 more
wiley   +1 more source

Thermal Stress Analysis of Transversally Corrugated Tube in Solar Receiver Under Semi-Circumference Heating [PDF]

open access: yes
ObjectiveIn daily operation, the outer wall of solar receiver tube is subjected to uneven heat flux between the inner and outer sides at cylindrical receiver, which leads to the uneven distribution of wall temperature and large temperature gradient.
CHEN Jiashu   +4 more
core   +1 more source

Investigation and Development of the High-Efficiency Vertical Chip [PDF]

open access: yes, 2015
GaN基LED一般生长在蓝宝石衬底上,由于蓝宝石是绝缘体和不良的导热物质,使得传统的正装芯片在大功率下工作时,容易因散热不佳导致失效。本论文利用外延转移技术把蓝宝石衬底更换成更好的导热导电衬底,制备成薄膜垂直芯片,以利于大电流,大功率下应用。 本论文所述芯片,使用ICPdamage作为电流阻挡层,使用基板键合技术将导电导热衬底和GaN结合,然后用激光剥离方式将蓝宝石衬底去除,为了增加出光效率,对GaN表面进行粗化。 我们发现PCB-ICP条件会导致垂直结构LED在老化过程发生漏电 ...
梁兴华
core  

Prioritized Lithium Extraction From Spent Lithium‐Ion Batteries via Low‐Temperature Chlorination Mediated by Seawater‐Derived Chlorides

open access: yesRare Metals, EarlyView.
ABSTRACT Chlorination roasting has emerged as a promising pyrometallurgical strategy for the selective recovery of lithium from spent lithium‐ion batteries (LIBs). In this study, a natural roasting agent, seawater‐derived chlorides, was employed to selectively extract lithium from spent LiNi0.5Co0.2Mn0.3O2 (NCM523) cathode. MgCl2·6H2O, a main component
Bei‐Lei Zhang   +7 more
wiley   +1 more source

Effect of Residual Thermal Stresses on Fracture Behavior and Mechanical Properties of Al sub 2 O sub 3/Ni Cermets [PDF]

open access: yes, 2002
Effect of residual thermal stresses on fracture behavior and mechanical properties of Al2O3/Ni cermets was qualitatively explained by using theory on residual thermal stresses. When Ni particles are located within Al2O3 grains or Ni content is relatively
Chen, Da Ming   +3 more
core   +1 more source

Tantalum‐Driven Interfacial Reconstruction Enables Ultra‐Low Contact Resistance in TiAlTa/Au GaN HEMTs

open access: yesRare Metals, EarlyView.
ABSTRACT The transformative potential of gallium nitride high electron mobility transistors (GaN HEMTs) in advancing carbon‐neutral power systems remains bottlenecked by contact resistance (Rc) at the metal–semiconductor (M‐S) interface, a critical determinant of switching losses and frequency response.
Ji‐Zhou Zhang   +8 more
wiley   +1 more source

The fundamental material design of low thermal expansion coefficient Ni-Fe-Cr based superalloy [PDF]

open access: yes, 2016
超超临界火力发电技术有着二氧化碳排放量少、发电效率高的优点,世界各国均在大力研究该技术。下一代容量越大,参数越高(温度和压力越高)的超超临界机组会排放越少的温室气体且发电效率更高,但是服役环境的更加苛刻,也要求所用材料的性能应更加优异。 在超超临界技术火力发电所用的材料中,镍基高温合金具有较高的强度以及优异的抗氧化腐蚀等性能,是其中最重要的合金之一,但其有两个不利因素:(1)热膨胀系数(CTE)较高,其与9-12%Cr的耐热钢焊接或者组装时产生较大的热应力,易造成焊接开裂或装配失效;(2)价格较高 ...
池天惠
core  

Orbitally Driven Anomalous Thermal Transport Under High Pressure in Gallium Nitride

open access: yesRare Metals, EarlyView.
ABSTRACT Extreme conditions such as high pressure offer opportunities for innovative materials design and applications. For over a century, studies on thermal transport in crystals under high hydrostatic pressure have shown that lattice thermal conductivity generally exhibits a monotonic increase with pressure.
Zong‐Hao Yuan   +8 more
wiley   +1 more source

Investigation of oxygen precipitates and the stability of denuded zone in Czochralski silicon [PDF]

open access: yes, 2016
铜在硅中不仅具有很大的扩散速率,而且随着温度的降低它的固溶度迅速下降,这两个特性使得铜原子很容易在器件制备过程中沉淀下来,严重影响硅片性能。虽然科研工作者们已经提出了多种工艺使硅片近表面处形成洁净区,但却很少对硅中的氧沉淀和洁净区的稳定性进行深入探讨。因此,本文通过实验分析了氧沉淀和洁净区的稳定性,得出以下结论: (1)研究了热处理方式和铜引入温度对洁净区的形成及其稳定性的影响。研究发现,只有Ramping-低-高热处理能使硅片内生成大量氧沉淀的同时有效形成洁净区。引入铜玷污后,RTP-低 ...
吕耀朝
core  

Experimental study on deformation and damage characteristics of liquid CO2 freeze-thaw coal [PDF]

open access: yes
Improving the permeability of coal seam is a common method to improve the efficient extraction of coal seam gas. Using liquid CO2 as fracturing medium to freeze-thaw coal is one of the methods to improve the permeability of coal seam.
ChaoJun FAN   +5 more
core   +1 more source

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