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51.
研究了Zn-1.2Cu-1.2Mg-xGd(x=0,0.1,0.25,0.5,质量分数,%)锌合金微观组织、在模拟体液中的腐蚀行为和力学性能。结果表明,锌合金组织主要由Zn固溶体和Mg2Zn11金属间化合物组成。当Gd添加量为0.5%时,形成了GdZn12化合物。锌合金的硬度随Gd添加量的增加而增加,在0.5% Gd添加量时,硬度达到最大值为1530 MPa。在0.25% Gd添加量时锌合金具有高的抗拉伸强度,而在0.1% Gd添加量时锌合金具有最低的腐蚀速率。 相似文献
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本文以乳清蛋白(Whey protein concentrate,WPC)和卵清蛋白(Egg white protein,EWP)为成膜基质,添加5 U/g蛋白转谷氨酰胺酶(Transglutaminase,TG)制备WPC/EWP复合膜,分别研究WPC和EWP质量比、膜液pH、甘油添加量对WPC/EWP复合膜结构及性能的影响。结果表明,当WPC/EWP质量比为1:3,成膜液pH为8,甘油添加量为35%时,电镜结果表明形成的复合膜结构致密无孔隙,红外结果显示WPC和EWP有较好的相容性。WPC/EWP复合膜的水蒸气透过率为2.08×10?10 g·s?1m?1Pa?1,透光率为73.90%,抗拉强度为1.60 MPa,断裂伸长率为151.96%。WPC、EWP和甘油在膜液pH为8时具有良好的融合性,能显著(P<0.05)提高WPC/EWP复合膜的机械性能。 相似文献
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Yajing Zhao Guowu Tang Puxian Xiong Qianyi Chen Yongsheng Sun Zhiduo Wang Dongdan Chen Zhongmin Yang 《Journal of the American Ceramic Society》2023,106(8):4634-4642
Demands are increasing for ultrashort pulse laser in industrial applications, where the gain bandwidth of most optical fiber material is not wide enough, and developing a wide bandwidth gain medium is challenging. Glass–ceramic fibers containing Nd3+/Yb3+ co-doped YCa4O(BO3)3 nanocrystals were fabricated by the molten core method and successive heat treatment. After a careful heat treatment, Nd3+/Yb3+ co-doped YCa4O(BO3)3 nanocrystals were precipitated in the fiber core. Enhanced broadband near-infrared (NIR) emission from 850 to 1150 nm (bandwidth: ∼252 nm) was obtained in the glass–ceramic fiber compared to that of precursor fiber. These results suggest that the Nd3+/Yb3+ glass–ceramic fibers are promising for broadband NIR optical amplifications and lasers. 相似文献
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Lei Zhong Qianyi Huang Fan Wu Guihai Chen 《Wireless Communications and Mobile Computing》2015,15(9):1320-1330
Auctions have been shown to be able to tackle the problem of spectrum scarcity effectively, but most of existing works only focus on static scenarios. They cannot deal with the requests of spectrum users as they arrive and leave dynamically. Bidders can either cheat by bidding untruthfully or cheat about the arrival and departure time. In this paper, we model the radio spectrum allocation problem as a sealed‐bid online combinatorial auction and propose a truthful mechanism called TRADE. TRADE is a truthful and an individual rational mechanism with polynomial time complexity. It can prevent bidders from cheating in the auction while achieving good bidder satisfaction, spectrum utilization, and social welfare. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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采用正硅酸乙酯(tetraethyl orthosilicate.TEOS)和Cu、Co、Mn的醋酸盐溶液.通过溶胶-凝胶法、常压干燥制备了过渡金属氧化物含量高达75wt%的CuO(coO,MnO)/SiO2纳米复合气凝胶.采用透射电镜(TEM),傅里叶变换红外分析(FTIR)、电子散射能谱分析(EDS)和化学分析等对其微观结构、组成及成胶机理进行了探讨.结果表明:CuO(coO,MnO)/SiO2纳米复合气凝胶的颗粒约在5~10nm,并具有SiO2气凝胶的纳米孔隙三维网络结构和高比表面积;根据过渡金属醋酸盐与TEOS比例的不同,Cu、Co和Mn能够与氧在网络结构中形成不同程度的-0-M-o-桥键连接;通过气凝胶的多孔网络分隔作用,可使更多金属氧化物CuO、CoO和Mno的纳米粒子均匀分散于CuO(coO,MnO)/SiO2复合气凝胶或SiO,气凝胶骨架中.这种结构既有利于提高催化剂负载量,又可充分利用CuO,CoO和MnO的助催化作用. 相似文献
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In recent years, flexible electronic devices have become a hot topic of scientific research. These flexible devices are the basis of flexible circuits, flexible batteries, flexible displays and electronic skins. Graphene-based materials are very promising for flexible electronic devices, due to their high mobility, high elasticity, a tunable band gap, quantum electronic transport and high mechanical strength. In this article, we review the recent progress of the fabrication process and the applications of graphene-based electronic devices, including thermal acoustic devices, thermal rectifiers, graphene-based nanogenerators, pressure sensors and graphene-based light-emitting diodes. In summary, although there are still a lot of challenges needing to be solved, graphene-based materials are very promising for various flexible device applications in the future. 相似文献
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为提高大鲵下脚料的综合利用价值,以人工养殖大鲵肝脏为原料,采用酶解法提取大鲵肝油。先对蛋白酶进行了筛选,再采用单因素实验考察了pH、液固比、酶添加量、酶解时间、酶解温度对大鲵肝油提取率的影响,在此基础上利用响应面法优化大鲵肝油提取的工艺条件,并对精炼前后大鲵肝油的理化指标及脂肪酸组成进行了测定。结果表明:大鲵肝油提取的最优工艺条件为选用木瓜蛋白酶、pH 6.5、液固比2.5∶1、酶添加量2 100 U/g、酶解时间4 h、酶解温度65℃,在此条件下大鲵肝油提取率为79.92%;粗制大鲵肝油的酸值(KOH)为5.73 mg/g,过氧化值为1.04 mmol/kg,碘值(I)为124.60 g/100 g,不饱和脂肪酸含量为69.75%;精制大鲵肝油的酸值(KOH)为0.93 mg/g,过氧化值为0.43 mmol/kg,碘值(I)为129.40 g/100 g,共检出18种脂肪酸,不饱和脂肪酸含量为73.55%,其中多不饱和脂肪酸含量为33.88%。使用木瓜蛋白酶酶解提取大鲵肝油反应条件温和、操作简便、提取率高,所得大鲵肝油品质好,不饱和脂肪酸含量丰富,具有较高的营养价值。 相似文献
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