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201.
D. Y. Cong Y. D. Zhang C. Esling Y. D. Wang X. Zhao L. Zuo 《Journal of Applied Crystallography》2011,44(5):1033-1039
The preferred martensitic variant distribution in Ni53Mn25Ga22 ferromagnetic shape memory alloy (FSMA) samples annealed without and with a high magnetic field of 12 T applied during the annealing process was investigated by electron backscatter diffraction. It is revealed that the high magnetic field applied during annealing enhances the regular arrangement of martensitic variants from the morphological point of view and effectively modifies the preferred orientation distribution of martensitic variants without changing the misorientation between them from the crystallographic point of view. Only one texture component, , exists in the sample annealed without a magnetic field, whereas two additional texture components, and , are developed in the sample annealed in a high magnetic field. The new finding that the preferred martensitic variant distribution can be efficiently modified by introducing a high magnetic field during the annealing process will shed light on the development of high‐performance polycrystalline FSMAs via novel processing techniques. 相似文献
202.
Hierarchical cobalt sulfide crystals with flower‐like microstructures were successfully prepared by a simple one‐pot solvothermal route, employing CoCl2·6H2O as a cobalt precursor and KSCN as a sulfur source. The morphology of these microstructures can be easily controlled by adjusting the molar ratio of glycol to DMF in the solvent. The products were characterized by XRD and SEM. Possible formation mechanisms of CoS hierarchical microspheres are proposed. The influences of the nature of reaction media on the morphological evolution were also investigated and it was found that the ratio of DMF to glycol was of great importance for the formation of CoS morphology. 相似文献
203.
Three kinds of novel indium oxide (In2O3) nanostructures, namely, nanorods, nanoflowers and nanowhiskers were synthesized on silicon substrate via a simple vapor‐phase transport method under atmospheric pressure. The In2O3nanostructures were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), and energy‐dispersive X‐ray spectrometer (EDS) spectrum. The Raman spectra of these nanostructures showed four sharp scattering peaks centered at 308, 365, 522, and 628 cm‐1, whose position and intensity were characteristic of standard Raman spectra for In2O3. The Room‐temperature photoluminescence (PL) spectra showed visible emissions centered around 576, 592, and 624 nm. Field emission measurements demonstrated that the nanoflowers possessed the best performance with a turn‐on field of 3.54 V/µm and a threshold field of 9.83 V/µm. And the field enhancement factors of these nanostructures are high enough for the application of field emission display devices. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
204.
Yun‐Ming Sun Feng‐Ying Dong Jian‐Min Dou Da‐Cheng Li Xi‐Ke Gao Da‐Qi Wang 《Crystal Research and Technology》2008,43(2):218-222
One metalorganic complex [K(cis‐syn‐cis‐ dicyclohexyl‐18‐crown‐6)]2[Cu(mnt)2] (mnt = maleonitriledithiolate) has been obtained by the reaction of dicyclohexyl‐18‐crown‐6 with K2mnt and CuCl2·2H2O. The title complex has been characterized by elementary analysis, FT‐IR, UV‐Vis spectroscopy and x‐ray single crystal diffraction. The title complex crystallizes in the triclinic space group P1 with crystallographic data: a = 10.870(6) Å, b = 11.536(6) Å, c = 12.904(7) Å, α = 101.541(10)°, β = 110.573(9)°, γ = 99.441(9)°, V = 1435.2(13) Å3, Z = 1, Dcalcd = 1.350 g/cm3, F(000) = 615, R1 = 0.0641, wR2 = 0.1475. It displays one‐dimensional chain‐like structure formed by [K(cis‐syn‐cis‐ dicyclohexyl‐18‐crown‐6)]+ complex cations and [Cu(mnt)2]2‐ complex anions through N‐K‐N interactions. Its electrochemical behavior has also been studied by the cyclic voltammetry. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
205.
从定常态电离层电荷守恒方程和欧姆定律出发,导出了适用于整个半球、同时包含中性风和场向电流这种效应的电离层电场、电流基本方程组.在电离层积分电导率和中性风已知的条件下。建立了两类定解问题,并给出了数值求解方案. 相似文献
206.
207.
This paper is concerned with a stabilized finite element method
based on two local Gauss integrations for the two-dimensional
non-stationary conduction-convection equations by using the lowest
equal-order pairs of finite elements. This method only offsets the
discrete pressure space by the residual of the simple and symmetry
term at element level in order to circumvent the inf-sup condition.
The stability of the discrete scheme is derived under some
regularity assumptions. Optimal error estimates are obtained by
applying the standard Galerkin techniques. Finally, the numerical
illustrations agree completely with the theoretical expectations. 相似文献
208.
209.
210.
基于流体体积法(volume of fluid,VOF),数值模拟了装满黏性液体的圆柱形汽缸中的裙带气泡的浮升运动,研究了侧壁面约束对裙带气泡浮升动力学的影响.用雷诺数(Re)、韦伯数(We)、长宽比(χ)、裙带厚度(T/d)和裙带长度(L/d)等参数来表征不同约束比条件下(1.1≤Cr≤10)裙带气泡的运动和变形特性,分别在全局参考系和局部参考系下分析了壁面对气泡内外流场的影响.模拟结果显示,当Cr≥8时,裙带气泡的行为特性与在无界流域条件下的情况相当,可视作壁面无关的.当Cr8时,壁面对裙带气泡的浮升速度和形状演化有显著影响.随着壁面的靠近,裙带气泡受到的阻力增大,造成浮升速度下降.约束比降低使裙带厚度增厚而长度变短直至裙带消失,裙带气泡受挤压而被拉长并逐渐变为椭圆球帽形最后到子弹形.相反,约束比增大时,裙带气泡尾流效应增强,气泡边缘处流场产生明显的循环流动(涡环),促使裙带的形成.研究表明壁面会加剧裙带气泡产生破碎,印证了前人的推断.模拟结果与已有的经验公式吻合良好,分析了前人公式的适用性. 相似文献