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1. chinaXiv:202001.00046 [pdf]

A general self-consistent framework for studying cumulative displacement damage in nanostructured metals based on parameter passing and structural feedback between atomic and coarse-grained techniques

Xiangyan Li; Yange Zhang; Yichun Xu; Xuebang Wu; Xianping Wang; B.C. Pan; C.S. Liu; Q.F. Fang; Jun-Ling Chen; G.-N. Luo; Zhiguang Wang; X. Liu
Subjects: Materials Science >> Materials Science (General)

Nano-crystalline metals (NCs) exhibit radiation-tolerance due to the sink of grain boundaries (GBs) for radiation-induced defects such as self-interstitial atoms (SIAs) and vacancies (Vs). However, the relevant mechanisms for the radiation damage accumulation and GB structural relaxation under high radiation field in NCs are still not well understood due to the lack of self-consistent across-scale techniques for simulating radiation-induced microstructures evolution. In this article, by combining coarse-grained and atomistic simulations, we proposed a coupling method to investigate the evolution of the microstructure and SIA/V-GB interaction under cumulative irradiation in NC iron. The SIA overloaded effect was revealed in iron GBs at a high radiation dose rate and/or low temperature. Two types of GB structural response were observed to cumulative irradiation. With the SIA accumulated at the GB, the new GB phase formed and then a critical concentration of the SIA at the GB transited to the small quantity of the V during the GB structural recovery, accompanied by the local GB motion. Consequently, the GB’s role for Vs nearby alternated between the trapping and annihilation center with radiation dose. Alternatively, GB developed to a disordered structure after trapping abundant SIAs. The GB response pattern to cumulative irradiation that is related to the SIA formation energy at the GB or the GB thermal stability is well manifested in the cumulative distribution function of the defects formation energy and its energy level density. The present work reveals the dynamic healing picture for radiation damage near the GB under cumulative irradiation.

submitted time 2020-01-07 Hits13021Downloads509 Comment 0

2. chinaXiv:201904.00103 [pdf]

A Novel Narrow-Band Green-Emitting Phosphor CsKNaLi(Li3SiO4)4 with the UCr4C4-Related Type Structure

师进生; 王丽丽; 孔晓颖; 李鹏; 兰学芳; 陈倩
Subjects: Materials Science >> Electronic, Optical and Magnetic Materials

我们成功合成了CsKNaLi(Li3SiO4)4:Eu2+ (CKNLLSO:Eu2+)作为UCr4C4型结构氧基家族的新成员。该荧光粉的基质化合物的晶体结构和能带结构分别通过Rieveld精修方法和密度泛函理论分析和计算。由于高度压缩和刚性的阴离子骨架,取代Cs格位的Eu2+在InGaN基紫外LED的激发下,发出了明亮的绿色荧光,半峰宽为55 nm.当温度升高到190℃时,CKNLLSO:Eu2+的稳定性仍然较好。采用浓度优化的CKNLLSO:4%Eu2+制成的LED器件发出的绿光的色坐标为(0.2320, 0.6016),相关色温为7314K。分析结果表明,这种荧光粉是一种很有前景的白光LED绿色荧光粉。

submitted time 2019-04-30 Hits13581Downloads848 Comment 0

3. chinaXiv:201902.00003 [pdf]

Magnetic field-dependent reversal effect of the electromagnet- induced normal stress of magnetorheological materials

Taixiang Liu; Yangguang Xu; Ke Yang; Lianghong Yan; Beicong Huang; Zhuo Zhang; Xiaodong Jiang; Hongwei Yan
Subjects: Materials Science >> Materials Mechanics

Magnetorheological (MR) materials are a type of magnetoactive smart materials, whose physical or mechanical properties can be altered by applying a magnetic field. In usual, MR materials can be prepared by mixing magnetic particles into non-magnetic matrices. In this work, the electromagnet-induced (or non-uniform magnetic field-induced) normal stress of MR materials is studied. It shows that the stress does not vary monotonically along with the enhancement of the applied magnetic field. There exists a field-dependent reversal effect of the variation of the stress. The reversal effect is thought resulting from that the ratio of interparticle repellent of parallel magnetic particles to the particle-electromagnet attraction gets enlarged along with the enhancement of the field.

submitted time 2019-02-01 Hits13155Downloads870 Comment 0

4. chinaXiv:201809.00158 [pdf]


Subjects: Materials Science >> Metals and Alloys

理解合金元素如何调制金属材料的弹性模量在固体物理理论及金属材料的机械性能的工程设计领域都很重要。本文采用第一性原理方法计在合金原子浓度在 0.4 到 1.85 at% 范围内 12 种铁基固溶体的弹性模量并研究合金元素对 bcc 铁基体弹性模量的机制。

submitted time 2018-09-14 Hits13529Downloads1031 Comment 0

5. chinaXiv:201809.00002 [pdf]

Pressure-Induced Indirect-Direct Bandgap Crossover and Bandgap Engineering in Ductile Semiconductor Ag3PO4 with Negative Linear Compressibility

Lu, Yang; Zhu, Shengcai; Huang, Eugene; He, Yu; Ruan, Jiaji; Yan, Hao
Subjects: Materials Science >> Materials Science (General)

Silver orthophosphate (Ag3PO4) has aroused widespread interest since the discovery of visible-light-driven photocatalysis activity. However, its indirect bandgap nature at ambient becomes an obstacle to improve the photocatalysis efficiency and use in other application fields. In this study, the indirect-to-direct bandgap crossover was found during the pressure-induced phase transition from cubic to trigonal phase in Ag3PO4. The observed bandgap narrowing could be partially retained after pressure was released to ambient conditions, accelerating to efficiently utilize the solar spectrum. Moreover, Ag3PO4 was ductile like metals. Unexpectedly, this ion-conducting and ductile semiconductor photocatalyst further exhibited the negative linear compressibility (NLC) at pressure range of 7.5-25 GPa. This work, combining experimental and theoretical tools, provides an insight into the modulation mechanism of the electronic structure for silver-based semiconductors, and may broaden the applications of Ag3PO4.

submitted time 2018-09-03 Hits12209Downloads994 Comment 1

6. chinaXiv:201801.00700 [pdf]

Morphogenesis of nacreous aragonite tablets: lessons from domed sheet nacre

Zhang, Gangsheng
Subjects: Materials Science >> Materials Chemistry


submitted time 2018-01-27 Hits13472Downloads1252 Comment 1

7. chinaXiv:201711.02640 [pdf]


刁加加,; 常春蕊,; 张志明,; 张好强,; 孙红婵,; 安立宝
Subjects: Materials Science >> Materials Science (General)


submitted time 2017-11-21 From cooperative journals:《材料研究学报》 Hits31212Downloads1522 Comment 0

8. chinaXiv:201711.02643 [pdf]


赵思勰,; 晏华,; 李云涛,; 汪宏涛,; 胡志德
Subjects: Materials Science >> Materials Science (General)


submitted time 2017-11-21 From cooperative journals:《材料研究学报》 Hits30661Downloads1479 Comment 0

9. chinaXiv:201711.02644 [pdf]


侯书亮,; 卢慧宫,; 顾逸凡,; 马小亮,; 吴一楠,; 王颖,; 李风亭
Subjects: Materials Science >> Materials Science (General)

以氧化铝、氢氧化铝、勃姆石为水不溶性金属源,用水热法合成了金属有机骨架MIL-53(Al)。使用SEM、XRD、氮气吸附和TGA表征了产物的形貌和结构,并与用传统水溶性硝酸铝合成的MIL-53(Al)对比。结果表明:使用三种水不溶性金属源都能合成典型的金属有机骨架材料MIL-53(Al)。用水热法制备的MIL-53(Al)产物的BET比表面积都在700~1000 m2/g。结果还表明,使用三种水不溶性金属源合成的MIL-53(Al)骨架的柔性(flexibility)与用常规铝硝酸盐合成的MIL-53(Al)不同。使用氧化铝合成的MIL-53(Al)常温下的孔道主要呈现大孔(lp)结构且骨架刚性较强。与使用其他铝源合成的MIL-53(Al)相比,用氧化铝合成的MIL-53(Al)对洛克沙胂有较好的吸附去除效果,吸附过程符合二级动力学模型。

submitted time 2017-11-21 From cooperative journals:《材料研究学报》 Hits27802Downloads1572 Comment 0

10. chinaXiv:201711.02646 [pdf]


卢秋影,; 姜宏伟
Subjects: Materials Science >> Materials Science (General)

在聚氧化丙烯多元醇(PPG)和二苯基甲烷二异氰酸酯(MDI)组成的交联聚氨酯(CPU)体系的基础上添加聚醚改性MQ树脂(E-MQ),制备出E-MQ树脂增强的浇注型聚氨酯弹性体。结果表明:E-MQ树脂与CPU有良好的相容性,制备出的E-MQ增强弹性体具有良好的力学性能。当E-MQ树脂用量为8%(E-MQ树脂占聚氨酯弹性体总质量分数)时增强聚氨酯弹性体的拉伸强度可达20.8 MPa,比CPU基础样提高22.4%,撕裂强度为82 kNm-1,邵尔A硬度为82度。

submitted time 2017-11-21 From cooperative journals:《材料研究学报》 Hits28510Downloads1461 Comment 0

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