摘要：Lowering the operating temperature of solid oxide fuel cells(SOFCs)has extensively stimulated the development of new oxide ion ***,inspired by the structural commonalities of oxide ion conductors,the inability to accommodate oxygen vacancies in the rigid,isolated,3-fold tetrahedral rings of SrSi/GeO_(3)-based materials,and the considerable flexibility of BO_(n) polyhedra in terms of coordination number,rotation,deformation,and linkage,we report the first borate-base family of oxide ion conductors,(Gd/Y)_(1−x)Zn_(x)BO_(3−0.5x),through combined computational prediction and experimental *** oxygen vacancies in(Gd/Y)BO_(3)can be accommodated by forming B_(3)O_(8)units in isolated,3-fold,tetrahedral rings of B_(3)O_(9)and transported through a cooperative mechanism of oxygen exchange between the B_(3)O_(9)and B_(3)O_(8)units,which is assisted by the intermediate opening and extending of these *** study opens a new scientific field of the borate system for designing and discovering oxide ion conductors.

摘要：The effect of porosity on compressive,bending,and tensile properties of the porous tantalum scaffolds fabricated by electron beam powder bed fusion(EB-PBF)was *** porous tantalum scaffolds with porosity from 69%to 77.8%were obtained by varying the designed porosity and adjusting the processing *** is found that the pores and unfused powder decrease with the increase of deposited energy *** decrease of porosity leads to an improvement in mechanical *** relevancy between compressive/bending/tensile yield strength and relative density can be described appropriately by exponential model,while the relationship between elastic modulus and relative density is in good agreement with the Gibson-Ashby *** the porous tantalum scaffolds exhibit good ductility in compressive,bending and tensile *** fragmentation of struts is observed during the compression process,but cracks are formed on the strut surface after 90°bending,mainly due to the high sensibility to defects caused by the oxide.

摘要：In order to improve the strength and corrosion resistance of CoCrNi medium entropy alloy,TiC strengthened CoCrNi medium entropy alloy(CoCrNi/(TiC)_(x)(x=0.1,0.2,0.4))was designed by addition of different amounts of *** effects of TiC content on the microstructure,mechanical properties,and corrosion resistance of the alloy were *** was found that the precipitation morphologies of TiC changed from lamellar eutectic to needle structure with the increase of TiC content,and finally formed mixed needled and bulk TiC *** appears as a dissolution−precipitation phenomenon in the CoCrNi alloy,which is important for the mechanical properties and corrosion resistance of the CoCrNi/(TiC)_(x) *** strength of alloy was enhanced obviously after the addition of *** compressive yield strength of CoCrNi/(TiC)_(0.4) alloy reached 746 MPa,much larger than that of the CoCrNi medium entropy alloy,108 ***,the addition of TiC was found to improve the corrosion resistance of CoCrNi medium entropy alloy in the salt solution.

摘要：The solar spectrum covers a broad wavelength range, which requires that antireflection coating （ARC） is effective over a relatively wide wavelength range for more incident light coming into the cell. In this paper, we present two methods to measure the composite reflection of SiO2/ZnS double-layer ARC in the wavelength ranges of 300-870 nm （duaI- junction） and 300-1850 nm （triple-junction）, under the solar spectrum AM0. In order to give sufficient consideration to the ARC coupled with the window layer and the dispersion effect of the refractive index of each layer, we use multidimensional matrix data for reliable simulation. A comparison between the results obtained from the weighted-average reflectance （WAR） method commonly used and that from the effective-average reflectance （EAR） method introduced here shows that the optimized ARC through minimizing the effective-average reflectance is convenient and available.

摘要：共晶高熵合金因其所展现出的特殊物理/化学性能而受到材料界的广泛关注.然而,除了FCC+B2系外,其他大部分所报道的共晶高熵合金系均呈现为固有脆性,这使得它们逐渐失去了工业应用的竞争优势.本工作提出了一种新的协同改善脆性CoCrNi_(2)(V_(3)B_(2)Si)_(0.2)共晶高熵合金强韧性的球化+再结晶工艺.基于该工艺,CoCrNi_(2)(V_(3)B_(2)Si)_(0.2)共晶高熵合金获得了一种精心设计的球状M3B2镶嵌在细小FCC晶界处的微观结构,使其抗拉强度、屈服强度和延伸率从923 MPa/620 MPa/1.3%提高到1326-1530 MPa/990-1330 MPa/8.4%-13.9%,提高了43.7%-65.8%/59.7%-114.5%/546%-9.69%.强塑化机制主要归因于球化和再结晶微观结构提供了更多的界面阻碍位错移动和促进了更加均匀的应力分布.该工作为协同改善脆性共晶高熵合金强韧性以满足工程安全性需求提供了新的思路.

摘要：作为一种材料基因特性的内禀属性,构型熵是材料基因组中一个新兴的指征因子.设计具有高构型熵的多组元热电材料,可以通过严重的晶格畸变显著降低晶格热导率,并通过提高晶体对称性改善塞贝克系数.然而,高构型熵也造成了载流子迁移率的恶化,从而限制了zT值的改善.本文通过在众所周知的(GeTe)_(1-x)(AgSbTe_(2))_(x),即TAGS合金中用Bi取代一半的Sb,设计了(GeTe)_(1-x)(AgSb_(0.5)Bi_(0.5)Te_(2))_(x),又称TABGS合金,以证明熵工程的有效性.鉴于TAGS合金的载流子平均自由程较低,已接近Mott-Ioffe-Regel极限,进一步的Bi置换和构型熵增加不会再损害载流子迁移率.此外,通过高构型熵抑制菱方-立方相变和降低的载流子浓度有助于大幅提高Seebeck系数.而且,AgSb_(0.5)Bi_(0.5)Te_(2)合金化诱导的多尺度微观结构和减小的声速有效地抑制了晶格热导率.因此,(GeTe)_(0.80)(AgSb_(0.5)Bi_(0.5)Te_(2))_(0.20)的最高zT值在723 K达到了1.60,300到773 K之间的平均zTave值达到了1.23.同时,由于固溶硬化其室温维氏硬度达到了2.21 GPa.这些结果强调了熵工程在提高热电性能方面的有效性,特别是对大量具有本征低载流子迁移率的材料而言.

摘要：A new process of AlN removal from secondary aluminum dross(SAD)by pyrometallurgical treatment with added cryolite was applied for solving the problem of recycling the secondary aluminum *** response surface methodology(RSM)was used to design experiments and optimize *** results show that adding the appropriate amount of cryolite can effectively promote the oxidation of AlN in the SAD,and too much cryolite will reduce the promotion *** effects of roasting temperature and cryolite on the denitrification rate are the most significant(p<0.0001)followed by holding *** values of the denitrification rate are found to be in good agreement with experimental values(R^(2)=0.9894 and R_(adj)^(2)=0.9775),which confirms the validity of the model *** optimum conditions of roasting temperature of 750°C,holding time of 194 min,mass fraction of cryolite of 17.7%are obtained according to the quadratic *** these conditions,the maximum actual denitrification rate reaches 94.71%and the AlN content in the SAD is only 0.55 wt%.The unfired brick with compressive strength of 18.62 MPa(GB/T 2542−2012)was prepared based on the roasted SAD.

摘要：The effects of cold-rolling reduction,annealing temperature,and time on recrystallization behavior and kinetics of cold-rolled Zr-1Sn-0.3Nb-0.3Fe-0.1Cr alloy were investigated using the Vickers hardness test,scanning electronic microscopy(SEM),transmission electron microscopy(TEM)and electron backscatter diffractometry(EBSD).The results show that the rate of the recrystallization increased with increasing annealing temperature and rolling *** grains nucleated preferentially at sites with high density dislocation and deformation stored energy and then grew into integral *** texture changed from-1010-//RD to-1120-//*** grain orientation changed from random orientation to the orientation with the maximum misorientation around 30°.Recrystallization kinetics and maps were constructed based on the Johnson-Mehl-Avrami-Kolmogorov(JMAK)equation to derive parameters sensitive to the *** activation energies for recrystallization of 30%,50%and 70%cold-rolling reductions were determined to be 240,249 and 180 kJ/mol,respectively.

摘要：层状氧化物因在钠离子电池正极中表现出的优异性能而引起了前所未有的关注,其中两种典型的P2和03型材料各具优势.因此,设计和开发包含P2和03材料的复合材料成为一种新的选择.但对这种具有多相结构的复杂正极材料的阴离子/阳离子的行为和结构演变过程的研究仍缺乏全面且深入的研究.本文基于两种典型的具有相同元素组成但不同的晶体结构的正极材料:P2型Na0.67Ni0.33Mn0.67O2和O3型NaNi0.5Mn0.5O2,开发了一种成分为Na0.732Ni0.273Mg0.096Mn0.63O2的双相材料,其中包含78.39 wt%的P2相和21.61 wt%的O3相.晶体结构分析和密度泛函理论(DFT)计算结果表明,该复合材料倾向于形成原子水平上的共生结构,且形成的双相结构的复杂晶格条纹可以阻止电极过程中过渡金属和氧原子迁移.相对于单相结构,双相结构提高了正极材料的储钠容量和稳定性,并增强了阴离子O2-/n-氧化还原的可逆性.此外,P2和O3结构共生的类异质结结构具有共享相边界,其形成的互锁效应可有效缓解P2和03结构在电极过程产生的晶格滑移和Na+离子脱出/嵌入的晶格应力.因此,共生的P2/03复合材料表现出较高的容量、较好的循环性能(0.1 C倍率下约有130 mAh g-1容量,循环200次后容量保持率为73.1%)和可逆的晶体结构转变.本文研究证实合理设计的双/多相正极可用于高能钠离子电池的应用.