排序方式: 共有110条查询结果,搜索用时 15 毫秒
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该文研究了振荡Robin混合边值齐次化问题解的收敛率.该工作的困难之处在于Robin边值上出现的振荡因子以及边界交叉项的处理.该文利用对偶方法巧妙得对振荡积分进行了估计.文中建立了解的H1和L2收敛率,所得结果明显地依赖于维数.该文可以视为将对偶方法和光滑算子,延拓到处理振荡Robin混合边值问题的情形. 相似文献
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We propose a novel method to search for the chiral magnetic effect(cme) in heavy ion collisions.We argue that the relative strength of the magnetic field(mainly from spectator protons and responsible for the cme)with respect to the reaction plane and the participant plane is opposite to that of the elliptic flow background arising from the fluctuating participant geometry.This opposite behavior in a single collision system,hence with small systematic uncertainties,can be exploited to extract the possible cme signal from the flow background.The method is applied to existing data from rhic,and the outcome discussed. 相似文献
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微波合成PtRu/C纳米催化剂及其对甲醇电化学氧化性能 总被引:4,自引:0,他引:4
PtRu/carbon nanosized catalyst with PtRu loading of 26.4wt% (Rt∶Ru=1.0∶1.0~1.1) was rapidly synthesized by the microwave polyol process employing the ethylene glycol solution of H2PtCl6 and RuCl3 as precursors in the presence of XC-72 carbon support. TEM observations demonstrated that microwave-prepared PtRu nanoparticles were narrowly distributed and highly dispersed on the carbon with an average size of 3.9 nm. Electrochemical experiments showed that microwave-synthesized PtRu/carbon catalyst exhibited very high catalytic activity for electro-oxidation of liquid methanol at room temperature. 相似文献
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以1,4-二乙基-7-羟基四氢喹喔啉-6-甲醛为基础,设计合成了一种具有长波长发射、较大斯托克斯位移的新型肼二腙类荧光探针L.在探针L的二甲基亚砜(DMSO)溶液中加入Cu~(2+)和CO~(2+)后,溶液颜色由黄色分别变为粉色和无色,可裸眼识别Cu~(2+)和Co~(2+).利用L与Cu~(2+)形成的配合物,在DMSO/H_2O(V:V=7:3,HEPES,1×10~(-2)mol/L,pH=7.4)缓冲溶液中可荧光"OFF-ON"识别H_2S.试纸条实验表明,L-Cu~(2+)对不同浓度H_2S显色明显,可以通过裸眼和荧光双通道快速检测H_2S.此外,利用Discovery Studio分子模拟软件,通过分子L结构反向找靶,并用CDOCKER程序进行分子对接,发现分子L对2x0v蛋白(来自人类的P53蛋白)有很好的结合作用,有望在医药领域得到应用. 相似文献
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Broadband transient reflectivity traces were measured for Bi_2 Se_3 thin films with various substrates via a 400 nm pump–white-light-probe setup. We have verified the existence of a second Dirac surface state in Bi_2 Se_3 and qualitatively located it by properly analyzing the traces acquired at different probe wavelengths. Referring to the band structure of Bi_2 Se_3, the relaxation mechanisms for photo-excited electrons with different energies are also revealed and studied. Our results show a second rise of the transient reflection signal at the time scale of several picoseconds. The types of substrate can also significantly affect the dynamics of the rising signal. This phenomenon is attributed to the effect of lattice heating and coherent phonon processes. The mechanism study in this work will benefit the fabrication of high-performance photonic devices based on topological insulators. 相似文献
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基于偶应力理论剪切带问题的弹塑性有限元分析 总被引:3,自引:0,他引:3
对于软化材料的剪切带问题,传统弹塑性有限元分析遇到了困难,进入弹塑性阶段,计算结果对网格划分敏感,出现所谓的有限元网格依赖性问题,随着网格的细分,计算常常因不收敛导致失效. 用有限元软件ABAQUS计算了3个例题,证实了传统弹塑性有限元分析软化材料剪切带问题的局限性,同时证实对于无剪切带的厚壁筒问题不会出现上述问题. 进一步引入细观非局部化理论,对非局部理论含有的细观参数\ell进行了深入讨论,并采用可通过C0 -1分片检验的18参偶应力三角形单元,重新计算了3个例题,结果避免了上述问题,说明细观偶应力有限元尤其适用于分析剪切带问题. 相似文献