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微波的频率高、波长短,具有似光波和似声波的特征,能形成方向性极强的波束,且其频带宽,携带信息量大,可无阻碍地穿透高空电离层等特点,在雷达、通信、电子对抗等方面得到了广泛的应用[1].微波吸收材料是在防止被雷达探测及跟踪而研究发展起来的隐身材料. 相似文献
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现代社会的发展带来了严重的电磁辐射和电磁污染的问题。吸波材料能够吸收微波的能量,减少反射,可以广泛地应用在抗电子干扰、电磁兼容、安全信息保密、人体安全防护等许多方面。理想的吸波材料应该具有吸收强、频段宽、质量轻等特点。橡胶为基体的吸波材料除了能有效耗散微波能量之外,还因其柔软、易剪裁、粘附性好的特点,在布置作结构复杂器件或腔体内部的吸波层时更有优势。本文介绍了吸波材料设计的基本原理,回顾了各类型橡胶吸波材料的特性,探讨了吸波剂种类和用量、吸波材料结构设计以及环境因素对橡胶吸波材料性能的影响,并对橡胶吸波材料未来的研究方向作出了展望。 相似文献
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Introduction Flavones and their derivatives existing in naturae are commonly contained in plants. The members of the flavone class show a wide variety of biological activities, such as anti-inflammatory[1], antimicrobial[2] and antitumor activities[3]. Schiff bases have been intensively investigated due to their antibacterial activity and antitumor property[4,5]. 相似文献
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Ferrocenyl imines 3a–f were synthesized using solvent-free methods by mixing ferrocene carbaldehyde 1 with amines 2a–f under microwave irradiation. The imines were obtained in good yield in short reaction times. 相似文献
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Two new imidazolidino Schiff base compounds, (E)-N-((quinoxalin-2-yl)methylene)- 2-(2-(quinoxalin-3-yl)imidazolidin-1-yl)ethanamine 1 and 2-(1-(2-(2-(quinoxalin-3-yl)imidazolidin- 1-yl)ethyl)imidazolidin-2-yl)quinoxaline 2, have been synthesized and characterized by elemental analysis, ^1H NMR, IR, MS and single-crystal X-ray diffraction. Crystallographic data for 1: C22H21N7, Mr = 383.46, monoclinic, space group P21, a = 7.0036(14), b = 6.9151(14), c = 19.701(4)A, β = 96.57(3)°, Z = 2, V = 947.9(3)A^3, Dc = 1.344 g/cm^3, F(000) = 404, μ = 0.085 mm^-1, Flack parameter = 0(2), R = 0.0464 and wR = 0.1055; and those for 2: C24H26N8, Mr = 426.53, triclinic, space group PI, a = 9.6680(19), b = 10.334(2), c = 11.389(2)A, α= 104.12(3), β = 102.95(3), γ= 100.48(3)°, Z= 2, V = 1041.2(4)A3, Dc= 1.361 g/cm^3, F(000) = 452, μ = 0.086 mm^-1, R = 0.0373 and wR = 0.1155. For the two compounds, the five-membered imidazolidine rings all adopt envelope conformation. Moreover, the title compounds show one-dimensional layered and three-dimensional supramolecular chainlike structures, respectively. Fluorescent properties of the two compounds have been investigated in the solid state at room temperature. Compound 1 exhibits strong fluorescence and thus may serve as excellent candidates of green fluorescent materials. 相似文献
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1 INTRODUCTION Schiff base ligands have been studied for a longtime due to the instant and enduring popularity fromtheir easy synthesis and versatility complexes. Theyplay an important role in the development of coor-dination chemistry as well as inorganic biochemistry,catalysis, optical materials and so on[1, . Consider- 2]able attention has been focused on the syntheses andstructures of copper(II) and nickle(II) complexes.The nickel complexes with multidentate Schiff baseligands have … 相似文献
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采用石胆酸与2-羟基-1-萘甲醛为原料,合成了一种新型甾体席夫碱结构荧光探针(L),其结构经NMR,IR,ESI-MS和元素分析表征。在pH 7.0缓冲溶液溶液中,探针L可以高选择性荧光识别Al^3+,检测限为8.0 nmol/L,适用范围为pH 6~10。当Al^3+与探针L配位时,生成1:1型配合物(L-Al^3+),在365 nm紫外灯照射下,由无色变成亮蓝色强荧光。 相似文献
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合成了4-(4-氯苯基亚甲基)亚胺-1,2,4-三唑希夫碱配体(L),以及希夫碱的配合物[Mn(SO4)(H2O)2L]n,并对配合物进行了结构表征。该配合物是1个用硫酸根桥连而成的一维链状配位聚合物,相邻的链通过水分子和硫酸根的氢键相互作用形成了二维超分子结构。利用DSC技术测试了配合物和固体推进剂主要组分(HMX,NC,RDX)的二元混合体系的热分解行为。本文也对配合物做了元素,红外光谱分析。 相似文献
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新型席夫碱大环化合物的合成 总被引:5,自引:0,他引:5
利用Mn2+, Ba2+作为模板离子, 由邻苯二胺和α,ω-二(3'-羟基-4'-甲酰苯氧基)取代烷[即1,4-二(3'-羟基-4'-甲酰苯氧基)丁烷、1,6-二(3'-羟基-4'-甲酰苯氧基)己烷、1,8-二(3'-羟基-4'-甲酰苯氧基)辛烷]反应分别合成了系列新型大环席夫碱化合物Ln (n=4, 6, 8). Mn2+用于L4合成, 并在洗涤时自动解络; L6和L8的合成以Ba2+模板, L6和L8的Ba2+配合物经与Na2SO4水溶液反应解络, 得到自由大环配体L6和L8. 上述新型大环席夫碱化合物采用元素分析, 1H NMR, IR, 紫外-可见光谱和MS等进行组成和结构表征. 相似文献
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双(5-磺酸钠水杨醛)缩二胺水溶性席夫碱的合成 总被引:3,自引:0,他引:3
水杨醛及其衍生物与某些伯胺类化合物缩合形成的席夫碱及其金属螯合物,具有特殊的抗癌、抗炎、杀菌抑霉等活性,引起了各国化学家的广泛兴趣[1,2].对水溶性席夫碱金属螯合物的研究,国内外报道较少[3,4],其合成方法主要采用水杨醛衍生物、金属盐、胺类的“一... 相似文献
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Schiff碱水杨醛缩异烟肼和水杨醛缩4-氨基安替吡啉的合成和晶体结构 总被引:15,自引:0,他引:15
通过水杨醛和异烟肼,4-氨基安替吡啉的缩合反应分别合成了Schiff 碱水杨醛缩异烟肼1,水杨醛缩4-氨基安替吡啉2,并获得其单晶结构。用元素分析,UV-Vis和IR谱进行表征。晶体结构通过X-射线衍射法测定,晶体结构均用直接法解出, 经全矩阵最小二乘法对原子参数进行修正。化合物1:化学计量式为:C13H11N3O2,Mr = 241.25,晶体属于单斜晶系,空间群P21/n, 晶胞参数:a = 8.153(1),b = 15.574(4) , c = 9.554(2) ? b =105.48(1)? V =1169.1(4) ? , Z = 4, Dc =1.371 g/cm3 , m =0.096 mm-1, F(000) = 504,结构偏离因子R = 0.0832, wR = 0.1158,共收集到2384个独立衍射点,其中其I >2(I)的可观测点为2059个。化合物2:化学计量分子式为:C18H17N3O2,Mr = 307.35,晶体属于单斜晶系,空间群P21/n, 晶胞参数: a = 7.597(1),b = 7.500(1) , c = 27.266(5) , b = 95.31(1), V = 1546.7(4) ? , Z = 4, Dc = 1.320 g/cm3 , m = 0.088 mm-1, F(000) = 648,结构偏离因子R = 0.0413, wR = 0.0952,共收集到3282个独立衍射点,其中其I >2(I)的可观测点为2711个。X-射线分析显示化合物1和2的晶体结构均由分子间氢键和-弱相互作用堆积而成的二维层状结构。 相似文献