Two-dimensional
materials, especially the newly emerging MXene,
have attracted numerous interests in the fields of energy conversion/storage
and electromagnetic shielding/absorption. However, the inherently
inevitable aggregation and absence of magnetic loss of MXene considerably
limit its electromagnetic absorption application. The introduction
of magnetic component and favorable structural engineering are the
alternatives to improve the microwave absorption (MA) performance.
Herein, we report a spheroidization strategy to assemble double-shell
MXene@Ni microspheres, where the commonly lamellar MXene are reshaped
into three-dimensional microspheres that provide the substrate for
oriented growth of Ni nanospikes. Whereas this structural feature
offers massive accessible active surfaces that effectively promote
the dielectric loss ability, the introduction of magnetic Ni nanospikes
enables the additional magnetic loss capacity. Benefiting from these
merits, the synthesized 3D MXene@Ni microspheres exhibit superior
MA performance with the minimum reflection loss value of −59.6
dB at an ultrathin thickness (∼1.5 mm) and effective absorption
bandwidth of 4.48 GHz. Moreover, the electron holography results reveal
that the high-density anisotropy magnetism plays an important role
in the improvement of MA performance, which provides an insight for
the design of MXene-based materials as high-efficient microwave absorbers.
Simultaneously developing protective electronics film for multi-spectra, including the radar, infrared (IR), and visible ranges, for both the military and civilian sectors is extremely challenging. The existing multi-spectracompatible materials mainly concentrate on either the radar/IR or IR/visible bands, trailing the rapid evolution of advanced devices for monitoring electromagnetic signals. Here, it is designed and fabricated an ultra-thin MXene-based composite film (20 µm) containing black phosphorus (BP) and Ni chains (M-B-M(Ni)) with integrated highly efficient thermal IR stealth, visible light absorption, and electromagnetic wave shielding. M-B-M(Ni) exhibits an extremely low IR emissivity of 0.1, decreasing the radiation temperature difference between the surrounding environment and target device. BP offers a high solar absorptance of 80%, which guarantees energy conversion from visible light to heat. Moreover, the absorption proportion of the electromagnetic shielding effectiveness for M-B-M(Ni) is 16% higher than that of pure MXene films (68.7%), owing to the improved magnetic loss by decoration with magnetic Ni chains. Due to the combined merits of MXene, BP, and Ni chains, M-B-M(Ni) opens an avenue for the construction of advanced multi-spectra compatible materials for versatile applications in thermal IR stealth, electromagnetic wave shielding, and energy transformation.
Maleimide, a common motif in a variety of natural alkaloids, has been extensively investigated due to its noteworthy biological activities and optical properties. Additionally, it can be transformed into many important heterocyclic frameworks such as succinimides, pyrrolidines, and 2-pyrrolidones. Thus, a great deal of attention has been focused on the development of new synthetic routes to access polyfunctionalized maleimides. In this article, the recent research progress in functionalization of double bond is reviewed based on maleimides according to Michael addition, oxidative coupling and cycloaddition reaction. Keywords maleimide; Michael addition; oxidative coupling; cycloaddition reaction 马来酰亚胺是一类海洋天然生物碱和生物活性分 子的重要结构母核, 例如海洋天然生物碱 Granulatimide (1)、Himanimide A (2)、Camphorataimide B (3)以及化合 物 4 等结构中含有马来酰亚胺的结构片段 [1~3] , 具有抗 肿瘤和抗菌等多种生物活性. 其中 Granulatimide (1)对 鼠 P388 白血病细胞的 IC 50 为 39 μmol/L [1] , 化合物 Himanimide A (2)对 LPS 诱导巨噬细胞因子 IL-6 抑制作 用的 IC 50 值达到 10 μg/mL [2] . 化合物 4 为 2017 年 Poulsen 等 [3] 报道的一种特异性 Porcupine(PORCN)抑制剂, 也可 以有效抑制 Wnt 信号通路, IC 50 为 0.4 nmol/L, 显示抗肿 瘤活性, 具有较好的研究价值和应用前景. 另外, 马来酰亚胺经化学转化还可以合成琥珀酰亚 胺、四氢吡咯和 2-吡咯酮等化合物, 如抗癫痫药苯琥胺 (Phensuximide, 5)、抗肿瘤药物米哚妥林(Midostaurin, 6)和天然产物(Amathaspiramide B, 7)等 [4,5] (图 1), 其中米 哚妥林为美国食品药品监督管理局(FDA)于 2017 年批 准上市的一种新型口服多靶点激酶抑制剂, 用于携带 FTL3 突变的急性髓性白血病(AML)患者的治疗 [4] .
Abstract-A novel dual-band bandpass filter based on shorted rectangular patch resonator is proposed and experimentally studied. The resonant modes and frequencies of the shorted rectangular patch resonator are analyzed. Based on miniature structure of the new resonator, a novel dual-band bandpass filter with good out-of-band performance is designed for demonstration. The experimental results agree well with numerical simulations.
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