| 1 | CaMoO_4:Dy^(3+),K^+ near White Light Emitting Phosphor:Structural,Optical and Dielectric Properties显示文摘Undoped,Dy^(3+) doped and Dy^(3+),K^+ codoped calcium molybdate phosphors have been synthesized by solid-state reaction method.X-ray diffraction studies reveal the tetragonal structure of the prepared phosphors having crystallite size 15-50 nm.Scanning electron microscopy(SEM) studies reveal the morphology and crystallite size of the prepared phosphors.Photoluminescence studies indicate that there are blue and yellow emissions at 489 and 576 nm,respectively corresponding to Dy^(3+) ion.The introduction of K^+ ion significantly influences the blue and yellow emissions which causes the near white light emission from this codoped phosphor.The intense absorption peak of the codoped phosphor at 210 nm is attributed to the band gap and a shoulder at 240 nm appears due to charge transfer from oxygen ions to neighbouring molybdenum ions. The band gap of the codoped phosphor is calculated as 5.5 eV from the absorption studies.The dielectric properties such as permittivity and dielectric loss are studied as a function of frequency. | S.K.Sharma S.Dutta S.Som P.S.Mandal | 2013 | Journal of Materials Science & Technology2013，29，7： | 2 |
| 2 | 通过使用耦合换热模型模拟通过柴油机活塞的热损失和研究热障涂层对换热损失的影响规律显示文摘壁面边界产生的热损失对内燃机的整体性能和效率起主要作用。通常恒温壁边界条件用于典型的发动机模拟开发[1-3]。由于涉及到发动机燃烧的复杂性,这些边界条件不能从试验中精确估计。因此,在发动机模拟中,这些边界条件引起了很多的不确定性和不定参数。在非稳态发动机计算流体动力学(CFD)模拟中通过实体壁的热传递过程建模,开发出更高精度的发动机模型。这些发动机模型可用于研究热损失对发动机效率的影响,并用于研究减少热损失的新设计方法。利用单缸柴油机与连接到流体域的固体活塞一起建模,通过耦合热传递(CHT)建模技术,模拟Navistar柴油机的完整循环热损失,然后根据嵌入在活塞表面内的热电偶的试验数据验证该CFD模型。来自模型的总体预测与试验观察紧密地匹配。经过验证的发动机模型被进一步用于探索热障涂层(TBC)应用于活塞燃烧室上的优点。TBC涂层产生的效果在热传递模型建模中被设定为热阻。全周期3D发动机模拟提供了对热损失的定量分析,从而提高了使用TBC涂层的计算效率,为往复式发动机的CHT建模建立了可靠的框架。 | P.Kundu R.Scarcelli S.Som A.Ickes Y.Wang J.Kiedaisch M.Rajkumar 闫红梅(译) 陈建伟(译) | 2018 | 汽车与新动力2018，1，4： | 0 |
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