Ni55Mn20.6Ga24.4铁磁形状记忆合金的铁性畴结构表征（英文）

采用扫描电声显微技术(SEAM)研究Ni55Mn20.6Ga24.4铁磁形状记忆合金的马氏体变体晶体畴与铁磁畴的微观结构及其耦合。每个晶粒内部都存在条状的马氏体孪生变体,并呈现典型的自协作组态。利用SEAM独特的亚表面成像能力,结合Bitter粉纹法原位对比了马氏体变体与磁畴的相互关系,发现马氏体变体与磁畴具有良好的重合性。利用SEAM和MFM两种技术证明了这个结论。该结果对进一步理解磁畴和马氏体变体晶体畴的相互关系有重要意义。     

镍-镓-铁系铁磁性形状记忆合金的阻尼性能

在分析相变温度和显微组织的基础上,采用低频扭摆仪研究了镍-镓-铁系铁磁性形状记忆合金的阻尼性能与应变振幅、频率及温度的关系.结果表明:Ni52Ga27Fe21合金的马氏体相变为热弹性马氏体相变,特征温度Ms、Mf、As、Af分别为69.3℃,60.2℃,93.6℃,102.6℃,室温下组织为板条状马氏体;镍-镓-铁系合...     

反式-1,4-聚异戊二烯(TPI)/石墨烯纳米复合材料力学性能的研究

以石墨烯为填料,反式聚异戊二烯为基体,通过熔融法制备了反式聚异戊二烯/石墨烯纳米复合材料,并对其力学性能进行了探讨。实验结果表明:随着石墨烯含量的增加,复合材料的拉伸强度和断裂伸长率增加。当石墨烯的质量分数为0.05%时,纳米复合材料拉伸强度最大,为44 MPa。添加石墨烯可以显著提高复合材料的力学性能。     

热疗用Fe2O3-SiO2-Y2O3-Al2O3微晶玻璃微球的制备与性能

采用火焰漂浮法制备新型含钇铁磁微晶玻璃微球(ferromagnetic glass ceramic microspheres,FGCMs),用以放疗与热疗相结合的医疗用途.通过热分析和X射线衍射(X-ray diffraction,XRD)研究热处理温度对FGCMs性能的影响.使用偏光显微镜观察FC-CMs的形貌.用振...     

Zn~(2+)、Sn~(4+)共取代对YIG铁氧体性能的影响

该文通过1 400℃固相烧结制备出Zn2+和Sn4+共取代的Y3Fe5-2xZnxSnxO12(x=0~0.35)铁氧体材料,详细研究了离子取代量对钇铁石榴石铁氧体微观结构及磁性能的影响。研究表明,Zn2+、Sn4+都进入了钇铁石榴石铁氧体的晶格中。随着离子取代量的增加,钇铁石榴石铁氧体的密度与饱和磁化强度先增大后减小;其磁损耗则先减小后增大,在x=0.25时磁损耗取得最小值。该研究进一步说明了Zn2+和Sn4+取代在一定范围内可有效降低材料的磁损耗及控制材料的饱和磁化强度。     

Oxidative Intercalation for Monometallic Ni2+‐Ni3+ Layered Double Hydroxide and Enhanced Capacitance in Exfoliated Nanosheets

Monometallic Ni²⁺‐Ni³⁺ layered double hydroxide (LDH) is prepared using a simple oxidative intercalation process and may be further exfoliated into positively charged Ni(OH)₂ unilamellar sheets. The superior capacitive behavior of the unilamellar sheets stranded in carbon nanotubes (CNTs) networks is achieved because of the complete interfacial charge storage arising from the confined Faradaic reactions at the interfacial region. 3D nanosheet/CNT composites are prepared using an in situ electrostatic assembly of positive charged sheets with CNTs bearing negative charges. The restacking of active nanosheets during electrochemical cycling is effectively prohibited. Consequently, the outstanding specific capacitance and remarkable rate capability of the nanosheet/CNT hybrid electrodes are demonstrated, making them promising candidates for high performance supercapacitors, combining high‐energy storage densities with high levels of power delivery.     

Porous Hybrid Network of Graphene and Metal Oxide Nanosheets as Useful Matrix for Improving the Electrode Performance of Layered Double Hydroxides

Mesoporous hybrid network of reduced graphene oxide (rG‐O) and layered MnO₂ nanosheets could act as an efficient immobilization matrix for improving the electrochemical activity of layered double hydroxide (LDH). The control of MnO₂/rG‐O ratio is crucial in optimizing the porous structure and electrical conductivity of the resulting hybrid structure. The immobilization of Co‐Al‐LDH on hybrid MnO₂/rG‐O network is more effective in enhancing its electrode activity compared with that of on pure rG‐O network. The Co‐Al‐LDH?rG‐O?MnO₂ nanohybrid deliveres a greater specific capacitance than does MnO₂‐free Co‐Al‐LDH?rG‐O nanohybrid. The beneficial effect of MnO₂ incorporation on the electrode performance of nanohybrid is more prominent for higher current density and faster scan rate, underscoring the significant enhancement of the electron transport of Co‐Al‐LDH?rG‐O. This is supported by electrochemical impedance spectroscopy. The present study clearly demonstrates the usefulness of the porously assembled hybrid network of graphene and metal oxide nanosheets as an effective platform for exploring efficient LDH‐based functional materials.     

Au‐Edged CuZnSe2 Heterostructured Nanosheets with Enhanced Electrochemical Performance

Two‐dimensional (2D) nanomaterials and heterostructured nanocrystals (NCs) are two hot topics in current nanoresearch. However, reports on heterostructured NCs with 2D features are still rare. In this work, we demonstrate a one‐pot colloidal chemistry route for synthesizing Au‐CuZnSe₂ heterostructures with spherical Au domains attached to the edge of a sheet of CuZnSe₂. This protocol involves the preferential formation of Au clusters and the seeded growth of CuZnSe₂ sheets because of the lattice matching of CuSe with Au. As an example to demonstrate the importance of such heterostructures, the electrochemical performance of Au‐CuZnSe₂ heterostructured nanosheets is compared with that of heterostructured nanorods, Au NCs, and CuZnSe₂ NCs. The heterostructured nanosheets exhibit the best electrochemical activity.     

Ice‐Templated Assembly Strategy to Construct 3D Boron Nitride Nanosheet Networks in Polymer Composites for Thermal Conductivity Improvement

Owing to the growing heat removal issue of modern electronic devices, polymer composites with high thermal conductivity have drawn much attention in the past few years. However, a traditional method to enhance the thermal conductivity of the polymers by addition of inorganic fillers usually creates composite with not only limited thermal conductivity but also other detrimental effects due to large amount of fillers required. Here, novel polymer composites are reported by first constructing 3D boron nitride nanosheets (3D‐BNNS) network using ice‐templated approach and then infiltrating them with epoxy matrix. The obtained polymer composites exhibit a high thermal conductivity (2.85 W m⁻¹ K⁻¹), a low thermal expansion coefficient (24–32 ppm K⁻¹), and an increased glass transition temperature (T_g) at relatively low BNNSs loading (9.29 vol%). These results demonstrate that this approach opens a new avenue for design and preparation of polymer composites with high thermal conductivity. The polymer composites are potentially useful in advanced electronic packaging techniques, namely, thermal interface materials, underfill materials, molding compounds, and organic substrates.     

Vertically Aligned WS2 Nanosheets for Water Splitting

Vertically aligned WS₂ (VAWS₂) nanosheet films are prepared using a lithium based anodization electrolyte to fabricate WO₃ films followed by sulfurization. The VAWS₂ synthesized here is self‐organized as a conformal structure to expose active edge sites for water splitting. These vertically aligned nanosheets are composed of exfoliated WS₂ to provide abundant active edges for catalytic reactions. Hydrogen evolution activity of the VAWS₂ is demonstrated to show high catalytic current, low onset overpotential and small Tafel slope. By certain measures, this VAWS₂ nanosheet film outperforms some of the state‐of‐the‐art hydrogen evolution reaction (HER) catalysts, which opens up a new pathway to simply and scalably fabricate high‐performance water electrolysis catalysts.