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81.
Painlevé property,local and nonlocal symmetries,and symmetry reductions for a (2+1)-dimensional integrable KdV equation 下载免费PDF全文
The Painlevé property for a(2+1)-dimensional Korteweg–de Vries(KdV) extension, the combined KP3(Kadomtsev–Petviashvili) and KP4(cKP3-4), is proved by using Kruskal’s simplification. The truncated Painlevé expansion is used to find the Schwartz form, the B?cklund/Levi transformations, and the residual nonlocal symmetry. The residual symmetry is localized to find its finite B?cklund transformation. The local point symmetries of the model constitute a centerless Kac–Moody–Virasoro algebra. The local point symmetries are used to find the related group-invariant reductions including a new Lax integrable model with a fourth-order spectral problem. The finite transformation theorem or the Lie point symmetry group is obtained by using a direct method. 相似文献
82.
57Fe Mössbauer spectrometry: A powerful technique to analyze the magnetic and phase characteristics in RE–Fe–B permanent magnets 下载免费PDF全文
This review summarizes the recent advances on the application of 57Fe M?ssbauer spectrometry to study the magnetic and phase characteristics of Nd–Fe–B-based permanent magnets. First of all, the hyperfine structures of the Ce2Fe14B,(Ce,Nd)2Fe14B and MM2Fe14B phases are well-defined by using the model based on the Wigner-Seitz analysis of the crystal structure. The results show that the isomer shift δ and the quadrupole splitting ?EQ of those 2:14:1 phases show minor changes with the Nd content, while the hyperfine field Bhfincreases monotonically with increasing Nd content and its value is influenced by the element segregation and phase separation in the 2:14:1 phase. Then, the hyperfine structures of the low fraction secondary phases are determined by the 57Fe M?ssbauer spectrometry due to its high sensitivity. On this basis,the content, magnetic behavior, and magnetization of the REFe2 phase, the amorphous grain boundary(GB) phase, and the amorphous worm-like phase, as well as their effects on the magnetic properties, are systematically studied. 相似文献
83.
Enhanced hyperthermia performance in hard-soft magnetic mixed Zn0.5CoxFe2.5−xO4/SiO2 composite magnetic nanoparticles 下载免费PDF全文
High quality Zn0.5CoxFe2.5?xO4(x=0,0.05,0.1,0.15)serial magnetic nanoparticles with single cubic structures were prepared by the modified thermal decomposition method,and Zn0.5CoxFe2.5?xO4/SiO2 composite magnetic nanoparticles were prepared by surface modification of SiO2.The magnetic anisotropy of the sample increases with the increase of the doping amount of Co2+.When the doping amount is 0.1,the sample shows the transition from superparamagnetism to ferrimagnetism at room temperature.In the Zn0.5CoxFe2.5?xO4/SiO2 serial samples,the maximum value of specific loss power(SLP)with 1974 W/gmetal can also be found at doping amount of x=0.1.The composite nanoparticles are expected to be an excellent candidate for clinical magnetic hyperthermia. 相似文献
84.
利用电催化技术开发新型能源,是用来替代传统能源的一种新策略,化石燃料的大量使用从而导致相关的环境问题将会得到良好解决。对于这些技术的推广,设计并制备出高效稳定的电催化剂至关重要。单原子催化剂(SACs)在载体上具有原子分布的活性位点,是催化领域的新兴材料,具有美好的应用前景,现已成为电催化领域的研究热点。在此综述中,详细阐述了单原子电催化剂的一般载体、制备方法及其先进表征方法。同时系统总结了单原子电催化剂在能量转化和环境保护(CO2还原、水裂解)方面的应用。基于各种单原子催化剂研究的最新进展,我们简单阐述了催化机制。最后,讨论了单原子催化剂在电催化方向发展的挑战和前景,我们希望为单原子电催化剂的合成、设计和应用提供经验,更好的促进在电催化能量转换方面的发展。 相似文献
85.
Let, be two independent,
-dimensional sub-fractional Brownian motions with respective indices.
Assume. Our principal results are the necessary and sufficient condition for the
existence and smoothness of the collision local time and the intersection local time of
and through chaos expansion and elementary inequalities. 相似文献
-dimensional sub-fractional Brownian motions with respective indices.
Assume. Our principal results are the necessary and sufficient condition for the
existence and smoothness of the collision local time and the intersection local time of
and through chaos expansion and elementary inequalities. 相似文献
86.
87.
Noninvasive glucose monitoring(NIGM) techniques based on optical coherence tomography(OCT) are affected by several perturbing factors, including variation of tissue temperature. We first design a temperature control module integrated with an optical scanning probe to precisely control the temperature of skin tissues. We investigate the influence of temperature on NIGM with OCT by correlation analysis at different depths of in vivo human skin. On average, the relative changes in attenuation coefficient( μt) per 1 °C of temperature lead to 0.30 ± 0.097 mmol/L prediction error of blood glucose concentration. For NIGM measurement methods using optical properties of the tissues, this effect can be taken into account. 相似文献
88.
设计并合成了四种基于10-甲基-10H-吩噻嗪-5,5-二氧化物为受体(A),9,9-二甲基-9,10-二氢吖啶(DMAC)或吩噁嗪(PXZ)为给体(D)的分子内电荷转移荧光化合物1a、1b、2a和2b,并研究它们的光物理和电化学性质.结果表明:2a甲苯溶液的最大发射波长(λmax)和除氧后的荧光量子效率(Φd)分别为422 nm和0.367,而1a和1b分别为455 nm、0.083和511 nm、0.098.室温下1a和1b掺杂的PMMA薄膜的荧光寿命(τfilm)分别为5.78和20.00μs.根据77 K时的时间分辨荧光和磷光光谱得到1a和1b的最低单重态(S_1)-最低三重态(T_1)的能级差ΔE_(ST)分别为0.203和0.177 e V,表明它们都是潜在的热激活延迟荧光(TADF)材料.热重分析表明四种化合物热分解温度高于420℃. 相似文献
89.
The authors would like to apologize for some mistakes in the letter on Chinese Optics Letters vol. 12, no. 11, page 111701 and wish to make the corrections described below: 相似文献
90.
用常规溶液法由氯化锰(MnCl2·4H2O)和4?甲基?1,2,3?噻二唑?5?甲酸(HL)反应制备了配位聚合物[Mn3(L)6(H2O)4]n(1),加入配体菲咯啉(phen)后合成了配合物[Mn2(phen)4(H2O)2Cl2](L)2·3H2O(2)。用元素分析、红外光谱、热重分析及单晶X射线衍射进行了配合物的表征。单晶结构分析表明:配合物1属单斜晶系P21/c空间群,3个锰离子通过6个L-中的氧原子双齿桥联,形成了线型三核簇合物单元,簇合物单元间又通过其中一个噻二唑环上的氮原子与另一个簇合物单元的锰原子配位,形成层状结构;配合物2属三斜晶系P1空间群,锰离子分别与1个氯离子、1个水分子和2个phen分子中的4个氮原子配位,形成六配位的扭曲八面体阳离子,与之电荷平衡的是L-。用溴化乙锭荧光光谱法研究了HL和配合物与DNA作用情况,结果表明配合物与DNA的作用强于HL,有平面型配体的配合物2的作用又强于配合物1。 相似文献