共查询到20条相似文献,搜索用时 31 毫秒
1.
Angad Kumar Singh Sanyucta Kumari Pawan Raj Shakya T.R. Rao 《Materials science & engineering. C, Materials for biological applications》2011,31(5):1111-1114
A nematogenic Schiff's base, N,N′-di-4-(4′-pentyloxybenzoate)salicylidene-l″, 3″-diamino-2″-propanol, (abbreviated as H2L6), was synthesized and its structure studied by elemental analyses, mass, NMR and IR spectra. The Schiff's base behaves as a dinegative hexa/tetradentate species in its metal complexes of the general formula, [ML6]n where MII═Mn, Co, Ni, Cu and Zn. Their structural characterizations were made by various spectroscopic techniques. 相似文献
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Conversion-electron Mössbauer spectra of epitaxial -Fe16N2 and -Fe8N films have been studied and their differences are discussed in detail. The Mössbauer spectrum of -Fe16N2 can be decomposed into three subspectra, which correspond to the 4d, 8h and 4c sites. The Mössbauer spectrum of -Fe8N can be fitted using four spectra based on a nitrogen-atom-random-distribution model. The average hyperfine field is larger (3%) for -Fe16N2 than for -Fe8N, which is approximately consistent with a 4.1% enhancement of the magnetic moments for -Fe16N2. The iron moments tend to locate in the film plane for -Fe16N2 and to arrange perpendicularly to the film plane for -Fe8N. 相似文献
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《Materials Chemistry and Physics》2004,83(2-3):323-327
Cadmium selenide has been synthesized directly from cadmium chloride in aqueous N,N′-dimethylformamide (DMF) by the use of cycloocteno-1,2,3-selenadiazole or the element itself as the source of selenium. The dark brown powders that are the end-products of these reactions were characterized by reflectance spectroscopy, powder X-ray diffraction and scanning electron microscopy. 相似文献
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Nidhi Rani Gupta Susheel Mittal Subodh Kumar S.K. Ashok Kumar 《Materials science & engineering. C, Materials for biological applications》2008,28(7):1025-1030
A liquid membrane based Zn2+ ion selective electrode containing N,N′-Bis(2-dimethylaminoethyl)-N,N′-dimethyl-9,10 anthracenedimethanamine (Bis(TMEDA) anthracene) (I) as ionophore has been prepared and characterized. The membrane comprises of PVC, ionophore and plasticizer in the ratio of 33:2:65, respectively. It showed the best response in terms of detection limit (1.5 × 10− 6 M) and working concentration range (1.0 × 10− 5 M to 1.0 × 10− 1 M) with Nernstian response towards Zn2+ ions. The electrode responds within 15 s of coming in contact with the solution. The potential response remains almost unchanged over a pH range of 3.0 to 7.5. The electrode can be used for at least 3 months without any considerable alteration in its response behavior. The proposed electrode revealed good selectivity towards Zn2+ ions over a number of alkali, alkaline earth, transition metals and some other heavy metal ions. The electrode has been used as an indicator electrode in the potentiometric titration of Zn2+ with EDTA. The proposed electrode also detected Zn2+ ions from real life samples. 相似文献
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一、引言过硫酸盐,由于其标准电位高(2. 01伏),至今仍是人们颇愿使用的一种漂白剂。但实际上,它是一种弱的漂银剂。为此,人们曾做过多种努力,试图用各种补加剂来为过硫酸盐漂银创造催化条件。业已报道过可以使用的补加剂有:鎓盐、芳胺及硫醇等化合物。 相似文献
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This study concerns the potassium persulphate electroinitiated polymerization of acrylamide, acrylonitrile andN, N-methylene-bisacrylamide on a 5182 aluminium-magnesium alloy. Kinetic studies of the polymerization gave the polymerization as -d[M]/dt=K(CD)0.99 [Persulphate]1.12 [M]2.33, whereCD is current density (mA cm–2), [M] is monomer concentration (mol cm–3),K is a constant andt is time (s). It is proposed that the thick swollen polymer coating restricted the diffusion of monomers and initiators to the electrode. The problem of mass transfer by diffusion in the present system was confirmed by measurements of the diffusion coefficient and by electron transfer fraction experiments carried out through the use of a cyclic voltammetry technique. 相似文献
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研究了N,N′,N″-三叔丁基-1,3,5-苯基-三酰胺成核剂对聚丙烯光学性能、力学性能、结晶形态、熔融和结晶行为的影响,结果表明,加入该成核剂使聚丙烯的雾度大幅度下降,光泽度大幅度提高;弯曲模量提高,拉伸强度和缺口冲击强度变化不大;球晶尺寸大大减小;熔点、结晶温度和结晶度提高。 相似文献
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Pawan Raj Shakya Angad Kumar Singh T.R. Rao 《Materials science & engineering. C, Materials for biological applications》2012,32(7):1906-1911
A mesogenic Schiff-base, N,N′-di-(4-decyloxysalicylidene)-2′,6′-diaminopyridine, H2ddsdp (abbreviated as H2L3) that exhibits nematic mesophase, was synthesized and its structure studied by elemental analysis, mass spectrometry, NMR & IR spectral techniques. The Schiff-base, H2L3, upon condensation with hydrated lanthanide(III) nitrates, yields LnIII complexes of the general composition [Ln2(L3H2)3(NO3)4](NO3)2, where Ln = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy and Ho. Among the metal complexes, only that of HoIII is found to be mesogenic with smectic-X and nematic phases. The IR and NMR spectral data imply a bi-dentate bonding of the Schiff-base in its zwitterionic form (as L3H2) to the LnIII ions through two phenolate oxygens, rendering the overall geometry of the complexes to seven-coordinated polyhedron, possibly distorted mono-capped octahedron. 相似文献
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N. A. Ovchinnikova E. A. Martynova N. A. Minaeva O. G. Ellert 《Inorganic Materials》2013,49(6):638-642
Reactions of the higher molybdenum and tungsten chlorides with phenyl isothiocyanate or with N, N′-dicyclohexylcarbodiimide and carbon dioxide in dichloroethane are the first to demonstrate the possibility of insertion of carbon dioxide in combination with other heterocumulenes into transition metal-halogen bonds. IR spectroscopy and elemental analysis data show that the reactions result in the attachment of the ligands at the same metal-chlorine bond and the formation of heteromolecular insertion products with the compositions $$\left[ {MoOCl_3 \left\{ {N\left( {Ph} \right)C\left( S \right)} \right\}_2 Nc\left( {Me} \right)Cl} \right]$$ and $$MCl_x \left\{ {OC\left( O \right)\left[ {\left( {Hex} \right)NCN\left( {Hex} \right)} \right]_2 } \right\}Cl,$$ where x = 4 and 5 for the Mo and W derivatives, respectively. 相似文献
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以4,4′-联萘胺为母体,以最常用的空穴传输材料N,N′-二(α-萘基)-N,N′-二苯基-4,4′-联苯胺(α-NPD)为样板,合成了新型空穴传输材料N,N′-二(α-萘基)-N,N′-二苯基-4,4′-联萘胺(α-NPN)。通过核磁共振氢谱和元素分析进行了结构表征。差热分析测定其玻璃化温度(Tg)达到128℃。相对于α-NPD,α-NPN的吸收光谱和光致发光光谱都发生了红移。循环伏安法测定其氧化电势为1.20V,比α-NPD的1.02V稍高。该化合物可发明亮的蓝色荧光(461 nm),积分球测定其薄膜荧光量子效率为8.5%,比α-NPD的5.5%高。初步确定α-NPN可作为有机电致发光空穴传输材料。 相似文献
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H. S. Nalwa T. Watanabe K. Ogino H. Sato S. Miyata 《Journal of Materials Science》1998,33(14):3699-3710
Two-dimensional charge-transfer molecules based on N,N-dialkyl-2,4-dinitro-1,5-diaminobenzene have been synthesized. 1H and 13C-NMR spectroscopy, elemental analysis and mass spectroscopy were used to elucidate their chemical structures. The physical and non-linear optical properties of this new family of dyes containing alkyl chain; C3H7, C6H13, C8H17, C10H21, C11H23 and C18H37 are discussed, taking into account the possible role of alkyl chain length. These two-dimensional molecules have a significantly large off-diagonal component in contrast to one-dimensional molecules. These compounds showed no powder second-harmonic generation (SHG) at 1.064 m being centrosymmetric, however, their poled guest-host systems with poly(methyl methacrylate) and co-crystals with p-nitroaniline were SHG active. Powder SHG as high as 37 times that of urea was observed from N,N-dihexyl-2,4-dinitro-1,5-diaminobenzene with its mixture with p-nitroaniline. Second-harmonic generation of N,N-dioctadecyl-2,4-dinitro-1,5-diaminobenzene (DIODD) was studied as Langmuir–Boldgett monolayers. The Langmiur–Blodgett monolayer of a 1: 1 mixture of DIODD and arachidic acid showed second-order non-linear optical coefficients d11 and d13 of 11 × 10–9 and 3.85 × 10–9 esu, respectively, at a tilt angle of 60°. For the first time, a relationship between the microscopic polarizabilities and the molecular orientation of two-dimensional charge-transfer molecules has been established. In the light of the present experimental and theoretical data analysis, the potential of two-dimensional charge-transfer molecules for second-order non-linear optics is discussed. 相似文献
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研究了酰胺化合物——N,N′-二苯基丁二酰胺(DPS)的用量和结晶温度对聚丙烯中β晶型含量和结晶度的影响。发现DPS是聚丙烯的高效β成核剂,随着DPS含量的增加,聚丙烯中β晶型含量不断增多。等温结晶试验表明,添加0.2%DPS的聚丙烯样品在结晶温度为120℃时生成最大含量β晶型,此时β晶型的相对含量达到89.06%。 相似文献
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The growth pressure-temperature region of cubic boron nitride (cBN) in the systems Mg-BN and MxNy-BN (MxNy=Li3N, Ca3N2, Mg3N2) has been redetermined using well-crystallized hexagonal BN (hBN) with low oxygen content (0.2%) as the starting material. The data on the MxNy-BN systems are compatible with the existence of two growth regions: a high-temperature region where cBN grows from a liquid phase, and a low-temperature region where cBN forms from solid-solid reactions. Previous data are discussed according to this model and possible solid-state reactions are proposed on the basis of thermodynamic considerations. The results for the Mg-BN system confirm the effect of the O2 content of the starting BN on the cBN growth region. The systems (MxNy + M)-BN (M=Al, B, Si, Ti) have been shown to produce cBN crystals of increased size and improved morphology (more compact and perfect) compared to those obtained with the MxNy-BN systems. Their colour is dark or black and their size reaches 0.6 mm. The effect of the relative proportions of M and MxNy on the growth region and yield has been determined and is discussed on the basis of the chemical reactions likely to occur. 相似文献
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《Materials Letters》2004,58(17-18):2256-2260
In order to identify a volatile metallo-organic precursor for the deposition of nickel films for CVD applications, equilibrium vapour pressure (pe) measurements were carried out on a N,N′-ethylenebis(2,4-pentanedion-iminoato)nickel(II) (Ni[(acac)2en]) by employing a TG-based transpiration method over the range 406 to 495 K leading to values of 118.0±4.1 and 83.3±3.8 kJ mol−1 for the standard enthalpies of sublimation and vapourisation, respectively of Ni[(acac)2en]. From the plot of log pe against 1/T, the melting point was derived to be 463 K, which is in reasonable agreement with 469±3 K reported in the literature and was also observed in DTA and melting point studies. 相似文献
18.
The Y3+/Ho3+, Y3+/Dy3+, and Dy3+/Ho3+ interdiffusion coefficients in the YBa2Cu3O7 ? δ-HoBa2Cu3O7 ? δ, YBa2Cu3O7 ? δ-DyBa2Cu3O7 ? δ, and DyBa2Cu3O7 ? δ-HoBa2Cu3O7 ? δ systems have been determined in air at a temperature of 1233 K by the Boltzmann-Matano method from the yttrium/holmium, yttrium/dysprosium, and dysprosium/holmium concentration profiles across the diffusion zone between two pellets of the high-T c superconductors. The composition dependences of the interdiffusion coefficients in the solid-solution systems are presented. 相似文献
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The compositions of high magnesium content -magnesium sialon crystals within the 3M/4X plane of the Mg-Si-Al-O-N system indicate some form of metal atom ordering wihtin the structure. Although it is not possible using X-ray diffraction to detect weak additional reflections arising from the ordering between magnesium, aluminium, and silicon atoms, such weak reflections are revealed on electron diffraction photographs for a phase, resulting in a tripling of the hexagonal latticec-dimension. These show to have a structure very similar to rhombohedral willemite (Zn2SiO4), with the (Mg, Al) metal atoms ordered with respect to the silicon atoms in a 21 ratio. However, there are some additional weak diffraction spots with indices not obeying the rhombohedral condition of –h+k+l=3n. It is proposed that the structure of this is identical to that of willemite and the extra spots are a result of some form of twinning, which implies the existence of ordered microdomains. 相似文献
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Extraction of microamounts of Eu and Am with a nitrobenzene solution of chlorinated hydrogen dicarbollylcobaltate (H+B−) in the presence of N,N′-diethyl-N,N′-diphenyl-2,6-dipicolinamide (EtPhDPA, L) was studied. The equilibrium data were interpreted assuming that the complexes HL+, HL2+, ML23+, ML33+, and ML4/3+ (M3+ = Eu3+, Am3+) are extracted into the organic phase. The extraction and stability constants of the species in water-saturated nitrobenzene
were determined. The stability constants of the related complexes EuL
n
3+ and AmL
n
3+, where n = 2, 3, 4, in this medium are comparable. 相似文献