摘要：Sodium-ion batteries are promising for large-scale energy storage due to sodium's low cost and infinite abundance. The most popular cathodes for sodium-ion batteries, i.e., the layered sodium-containing oxides, usually exhibit reversible host rearrangement between P-type and O-type stacking upon charge/discharge. Herein we demonstrate that such host rearrangement is unfavorable and can be suppressed by introducing transition-metal ions into sodium layers. The electrode with stabilized P3-type stacking delivers superior rate capability, high energy efficiency, and excellent cycling performance. Owing to the cation-mixing nature, it performs the lowest lattice strain among all reported cathodes for sodium-ion batteries. Our findings highlight the significance of a stable host for sodium-ion storage and moreover underline the fundamental distinction in material design strategy between lithium-and sodium-ion batteries.

摘要：高容量材料对于实现锂离子电池高能量密度至关重要.本文通过一种新颖、简便的冷冻干燥与原位镁热还原相结合的方法,以二氧化硅和氧化石墨烯为原料制备了一种高度分散的三维石墨烯包裹多孔纳米硅复合负极材料(P-Si@rGO).该材料具有许多吸引人的特性:高度分散和被单独包覆的硅颗粒,硅和石墨烯之间紧密的Si–O–C相互作用,硅结构的多孔设计以及高孔隙率.这些优点显著增强了电极的反应动力学,赋予了复合材料更大的电接触面积和足够的缓冲空间以应对硅在锂化/脱锂过程中的体积变化,最终使P-Si@rGO获得优异的循环稳定性.本文研究了复合材料的相组成和微观结构对其电化学性能的影响,分析了电极在循环后期容量增加的原因,为硅基负极的功能化演变提供了新的思路.

摘要：巧妙的微观结构设计和合适的多组分策略仍然是高效吸收型电磁干扰屏蔽材料在轻质、低填充水平和薄样品厚度方面的挑战.本文基于独特的屏蔽胶囊结构,采用浸渍法制备了柔性水性聚氨酯/介电碳纳米管/磁各向异性镍(链或花)电磁屏蔽复合海绵.结果表明,增加镍(花状或链状)填料的含量可显著提高复合材料的导电性和电磁干扰屏蔽性能.水性聚氨酯/碳纳米管/8 wt%镍花-三聚氰胺海绵和水性聚氨酯/碳纳米管/8 wt%镍链-三聚氰胺海绵的电磁屏蔽性能分别为42.8和46.7 dB,优于仅含碳纳米管的复合海绵.碳纳米管与镍(花状或链状)之间的协同作用意味着复合海绵的屏蔽电磁干扰的主要机制来自于吸收过程.重要的是,在水性聚氨酯层的保护下,复合材料在强烈的物理和化学损伤下仍然表现出良好的电磁屏蔽性能.这项工作为设计新颖、轻量化和高效的电磁屏蔽复合材料提供了一种简单的协同策略,在便携式和可穿戴电子设备中显示出巨大的应用前景.

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：In order to achieve an access to strain sensor data with wireless transmission in bridge engineering structure testing, a wireless strain test system is presented based on the resistance strain sensor of networks. The wireless bridge strain test system composed of master station and substation adopts the wireless method to realize the high accuracy data acquisition between the master station and the substation under a reliable communication protocol. The system has been tested in contrast with the present strain apparatus. Results show that the wireless system is high-reliable, and has many characteristics such as high efficiency, good precision, high stability with low cost, and good flexibility, without using the present communication network.

摘要：为优化设计盘间距,本文采用不同盘间距比值的双盘桩模型对其进行抗拔能力试验。使用有限元数值模拟对双盘桩上拔期间桩周土的破坏进行评价。试验结果表明,当盘间距比值为6或8时双盘桩的抗拔力达到峰值;当盘间距比值小于6时,上盘比下盘承担更多荷载;当盘间距大于8时,下盘承担更多荷载。

摘要：使用低成本、高安全性的水系电解液使二次锌金属电池(AZMBs)成为大规模储能系统是最有前途的选择.然而,锌金属负极在水系电解液中热力学稳定性较差,严重阻碍了AZMBs的实际应用.在此,我们通过在锌表面涂覆氟化石墨并利用氟化石墨和锌之间原位的界面反应开发了一种富氟的杂化人工固体电解质界面来解决上述问题.疏水的氟化石墨可以有效地限制电解液和电极之间的接触,从而显著提高锌负极的抗腐蚀能力.同时,由氟化石墨和锌原位反应生成的ZnF_(2)共同组成的富氟杂化界面可以促进Zn2+的脱溶剂化作用,并均匀化锌离子通量,从而有效地抑制了副反应发生和枝晶生长.因此,在苛刻的测试条件下(10 mA cm^(−2),1 mA h cm^(−2)和30 mA cm^(−2),10 mA h cm^(−2)),对称电池可以分别稳定地循环1400和200小时以上,远远超过了裸锌的性能.此外,使用载量为6 mg cm^(−2)的MnO_(2)正极组装的Zn/MnO_(2)全电池在1 A g^(−1)的条件下经过2000次循环,仍能保持80%以上的容量.本文提出的这种构建富氟杂化ASEI的方法可以为设计高性能AZMBs提供一种有效的潜在策略.

摘要：The finite element analysis (FEA) software Ansys was employed to study the stress state of the dies of both plane and non-plane parting face structures with uniform interference and the die of plane parting face structure with non-uniform interference. Considering the symmetry of the die, a half gear tooth model of the two-ring assembled die with 2.5 GPa inner pressure was constructed. Four paths were defined to investigate the stress state at the bottom corner of the die where stress concentration was serious. FEA results show that the change of parting face from non-plane to plane can greatly reduce the stress at the teeth tips of the die so that the tip fracture is avoided. The interference structure of the die is the most important influencing factor for the stress concentration at the bottom corner. When non-uniform interference is adopted the first principal stress at the corner on the defined paths of the die is much lower than that with uniform interference. The bottom hole radius is another important influencing factor for the corner stress concentration. The first principal stress at the corner of the plane parting face die with non-uniform interference is reduced from 2.3 to 1.9 GPa when the hole radius increases from 12.5 to 16.0 mm. The optimization of the die structure increases the life of the die from 100 to 6 000 hits.

摘要：Three-dimensional(3D)tumor models prepared from patient-derived cells have been reported to imitate some of the biological development processes of in situ tumors in *** 3D tumor models share several important characteristics with their in vivo tumor ***,their applications in tumor modeling,drug screening,and precision-targeted treatment are ***,the establishment of tumormodels is subject to several challenges,including advancements in scale size,repeatability,structural precision in time and space,vascularization,and the tumor ***,bioprinting technologies enabling the editorial arrangement of cells,factors,and materials have improved the simulation of tumormodels in *** the 3D bioprinted tumor models,the organoidmodel has been widely appreciated for its advantages of maintaining high heterogeneity and capacity for simulating the developmental process of tumor *** this review,we outline approaches and potential prospects for tumor model bioprinting and discuss the existing bioprinting technologies and bioinks in tumor model *** multidisciplinary combination of tumor pathology,molecular biology,material science,and additive manufacturing will help overcome the barriers to tumor model construction by allowing consideration of the structural and functional characteristics of in vitro models and promoting the development of heterogeneous tumor precision therapies.

摘要：本文设计并制造了一种能够制备高质量非晶复合材料条带的新型配有水冷铜板的双辊铸轧原型机.利用该轧机在不同温度下成功制备了具有三种不同体积分数β-Ti枝晶的非晶复合材料带材(简称BT30,BT48和BT60),并通过一系列三点弯曲试验研究了其力学性能.结果表明,在高温下轧制的带材,高温元素在中间区域富集,导致成分分布不均.此外,由于铸轧过程中热力耦合导致在非晶复合材料中存在较大的内应力,这会显著影响其力学性能.新型铸轧设备为制备非晶复合材料带材提供了新的途径,基于该设备进行的研究深化了对非晶复合材料带材微观组织及力学性能的理解.