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1. chinaXiv:201904.00103 [pdf]

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

师进非常; 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项目结构氧基家族的新成员。该荧光粉的基质化合物的结晶结构和能够带动结构分别通过Rieveld强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,代表Cs约位的Eu2+在InGaN基紫外LED的激发下,发生了了解的绿色荧光,一半头宽为55 nm.当温度上升到190℃经常,CKNLLSO:Eu2+的安定仍然较好。使用浓度优化的CKNLLSO:4%Eu2+制成的LED器件发出的绿光的质量坐标为(0.2320, 0.6016),有关色温为7314K。分析结果表明,这种荧光粉是同种非常有前景的白光LED绿色荧光粉。

submitted time 2019-04-30 Hits815, Downloads218, Comment 0

2. 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 Hits589, Downloads304, Comment 0

3. chinaXiv:201809.00158 [pdf]

Text_Figs_new.pdf

刘伟
Subjects: Materials Science >> Metals and Alloys

了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和金属材料的性质的工程计划领域都非常重要。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 铁基体弹性模量的体制。

submitted time 2018-09-14 Hits1143, Downloads512, Comment 0

4. 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 Hits915, Downloads447, Comment 1

5. chinaXiv:201801.00700 [pdf]

Morphogenesis of nacreous aragonite tablets: lessons from domed sheet nacre

Zhang, Gangsheng
Subjects: Materials Science >> Materials Chemistry

大发游戏网站矿化领域的研究者普遍接受珍珠层板片是由于非晶质碳酸钙(ACC)纳米颗粒相变而成为。但是,这些纳米颗粒在三维空间是怎样排列的和如何相变的仍不清楚。本文首次报道了同种新项目不成熟板片,即使“挺晶状板片”。这种板片发育在翡翠贻贝珍珠层中。通过与颗粒状板片形貌进行对照,我们发现ACC纳米颗粒通常自组装成垂直的团簇且相变成垂直定向的文石小晶。这种小晶体与无机成因的文石晶的平衡形状相同。最重要的是,我们第一发现和石板片和层间有机膜(ILM)上高的点角(99-126过)。立即标志ILM针对ACC纳米颗粒是非润湿的。这种不润湿性可能对珍珠层的景象成因有重要影响。

submitted time 2018-01-27 Hits1423, Downloads730, Comment 1

6. chinaXiv:201711.02640 [pdf]

金钱掺杂降低碳纳米管接触电阻的试验研究

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

降和金属之间的点电阻是碳纳米管在有些纳电子领域取得应用的前提,夹金纳米粒子可有效降低碳纳米管的点电阻。本文采用高温焙烧在碳纳米管表面构造缺陷和亲水基团,下一场以碳纳米管在氯金酸水溶液中超声浸泡以吸附氯金酸,再在氢气气氛下加热还原氯金酸为钱。环视电子显微(SEM)图表明碳纳米管被成功地糅了钱纳米粒子,X射线能量散射谱(EDS)和X射线光电子谱(XPS)标志金是唯一掺杂在碳纳米管上的粒子。夹后碳纳米管的拉曼光谱中G带波数下降说明对碳纳米管掺杂金为N项目掺杂。N项目掺杂剂将电子转移给邻近的碳原子,如果碳纳米管中的电子数量增加,随即增强了碳纳米管的导电性。使用介电电泳法将碳纳米管组装到部分金电极之间,连使用精密电感电容电阻(LCR)测试仪实时测量。结果表明碳纳米管与金钱电极之间的点电阻较掺杂前得到了有效改善,电阻值最大可退近50%。

submitted time 2017-11-21 From cooperative journals:《资料研究学报》 Hits15712, Downloads996, Comment 0

7. chinaXiv:201711.02643 [pdf]

石蜡/硅藻土定型相变材料的结构和热性能

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

因为硅藻土为载体、因为石蜡为相变材料,所以溶剂蒸发法制备出石蜡/硅藻土定型相变材料(PA/D-PCMs),使用SEM、FT-IR、TGA、DSC相当手段对那微观结构和热性能进行了特点。结果表明:硅藻土对石蜡的毛细管力及二者间形成的氢键能阻挡液态石蜡的渗出,如果PA/D-PCMs有很高的热稳定性,硅藻土的二级孔洞限制了部分石蜡的收获。硅藻土内部发生多相连通的导热通道,增强了石蜡的导热效果并增强了蓄放热速率。乘石蜡含量的附加PA/D-PCMs的X、Y和Z轴传热通道上声子的散射作用更激烈,如果其导热系数降低,但是具有更高的收获度同相变潜热。为保证PA/D-PCMs的结构稳定和好的热性能,石蜡的超级质量分数为45%。

submitted time 2017-11-21 From cooperative journals:《资料研究学报》 Hits15127, Downloads945, Comment 0

8. chinaXiv:201711.02644 [pdf]

回不溶性铝源合成金属有机骨架MIL-53(Al)连同对洛克沙胂的吧

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)

因为氧化铝、氢氧化铝、繁荣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特色了究竟的景象和结构,连和用传统水溶性硝酸铝合成的MIL-53(Al)对比。结果表明:使用三种和不溶性金属源还能够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)结果的BET比表面积都在700~1000 m2/g。结果还表明,使用三种和不溶性金属源合成的MIL-53(Al)架的柔性(flexibility)和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)常温下的咽喉主要表现很孔(lp)结构还骨架刚性较强。和使用其他铝源合成的MIL-53(Al)对比,所以氧化铝合成的MIL-53(Al)针对洛克沙胂有较好的吧去除效果,吸附过程符合二级动力学模型。

submitted time 2017-11-21 From cooperative journals:《资料研究学报》 Hits12603, Downloads1019, Comment 0

9. chinaXiv:201711.02646 [pdf]

聚拢醚改性MQ树脂增强聚氨酯弹性体

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

在聚氧化丙烯多元醇(PPG)和第二苯基甲烷二异氰酸酯(MDI)结合的到联聚氨酯(CPU)体系的基础上添加聚醚改性MQ树脂(E-MQ),筹备出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发生好的相容性,筹备出的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过。

submitted time 2017-11-21 From cooperative journals:《资料研究学报》 Hits13200, Downloads954, Comment 0

10. chinaXiv:201711.02645 [pdf]

11.5CrNbTi和15Cr0.5MoNbTi超越纯铁素体不锈钢的循环蠕变行为

应彩虹,; 陈立佳,; 刘天龙,; 郭连权
Subjects: Materials Science >> Materials Science (General)

针对11.5CrNbTi和15Cr0.5MoNbTi超越纯铁素体不锈钢进行650℃应力控制循环蠕变实验,研究了最大外加应力处引入的保时间对铁素体不锈钢的循环蠕变变形和断裂行为的影响。结果表明:保持时间的延伸使这少种不锈钢的最小循环蠕变速率增大,循环蠕变寿命和循环断裂周差减少。在相同的标准下,15Cr0.5MoNbTi不锈钢的循环蠕变抗力优于11.5CrNbTi不锈钢。立即少种不锈钢的循环蠕变断裂模式都为通过晶断裂,乘保持时间的延伸断口表面的蠕变孔洞增多,蠕变损伤作用增强。立即少种不锈钢循环蠕变后的微观组织都为亚晶,各错的滑移和到滑移是循环蠕变的重要变形机制。

submitted time 2017-11-21 From cooperative journals:《资料研究学报》 Hits13103, Downloads892, Comment 0

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