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61.
Thermally reversible light scattering (TRLS) films are prepared from ultraviolet (UV) curing of polyether urethane diacrylate (PEUDA) with dispersed low molecular weight 1-octadecanol (OD). Depending on the temperature, the OD domains are crystalline or amorphous and this produce opaque or transparent films in a reversible way. Stable optically transparent and light scattering states are obtained after 100 successive heating–cooling cycles. Moreover, morphologies of the OD domains could be varied significantly with the cure temperature and this led to notable discrepancy in optical properties. By using an UV-mask and curing in two steps at different temperatures, complex patterns could be recorded in the film that were encoded at high temperatures (60 °C) and revealed at low temperatures (i.e., at room temperature), which makes the film a candidate for thermo-optical recording medium. 相似文献
62.
63.
A new 3d–4f heterometallic coordination framework, {[Eu(ox)(H2O)4] · [CuBr(2‐pzc)2] · 4H2O} ( 1 ) [ox = oxalate; 2‐pzc = pyrazine‐2‐carboxylate] was synthesized and characterized by elemental analysis, IR spectroscopy and thermal analysis, as well as single‐crystal X‐ray diffraction. Complex 1 represents one 3D supramolecular heterometallic coordination framework that is assembled from rare lanthanide‐ox anionic chains and CuBr(2‐pzc)2 cationic units through hydrogen bonds. 相似文献
64.
Electrodeposition of Mg with Zn in acidic sulfate solutions with polyethylene glycol and octadecyl dimethyl benzyl ammonium
chloride as additives was investigated by scanning electron microscopy, X-ray diffraction, and potentiodynamic polarization
techniques. The results show that these two compounds act in a synergetic way to suppress Zn deposition markedly and facilitate
Mg reduction. Zn–0.46%Mg coatings are produced under high cathodic current densities, which have lower corrosion potentials
than Zn coatings and hydrogen evolution in neutral chloride solutions. Magnesium hydroxide may cause current oscillations
at high cathodic polarizations in plating solutions without zinc salts due to its formation and peel-off. An “induced co-deposition”
mechanism is proposed for Zn–Mg alloy electrodeposition. 相似文献
65.
Yunsheng Xue Jie Mou Yi Liu Xuedong Gong Yihua Yang Lin An 《Central European Journal of Chemistry》2010,8(4):928-936
The electronic absorption spectra of 29 phenyl-ring substituted chalcones have been investigated with the time-dependent density
functional theory (TD-DFT) and polarizable continuum TD-DFT (PCM-TD-DFT). It turns out that the hybrid PBE1PBE functional
with the 6-31G basis set provide reliable λmax when the solvent effects are included in the model. Comparisons with experimental values lead to a mean absolute error of
12 nm (0.136 eV). Moreover, the observed substituent effects are reproduced by calculation qualitatively. The λmax of substituted chalcone in phenyl ring A is less sensitive to substitution than that in ring B. The linear correlation of
Hammett’s substituent constants (σP) with LUMO energies is better with respect to HOMO energies. The calculation reveals that the maximum absorption band mainly
results from the π→π* transition from HOMO to LUMO. The analysis of the electron density plots of frontier molecular orbitals
show that most transitions should be of valence excitation nature.
相似文献
66.
Complete optimization was conducted for 136 polybromo-phenoxathiin congeners(PBPTs) on the B3LYP/6-31G* level with Gaussian 03 program.The structural parameters and thermodynamical parameters of each molecule were obtained under the standard state of 298.15 K and 1.013×105 Pa.Reverse linear regression was employed to establish the quantitative structure-property correlation models between heat capacity at constant volume(CVθ),entropy(Sθ),standard heat of formation(△fHθ) and standard free energy of formation(△fGθ) of PBPTs and the structural parameters(the most negative atomic charge(q-) and molecular average polarizability(α)).These models presented better correlations(r20.97).And they were validated by variance inflation factor(VIF) and t-test,which can better explain the regularity of thermodynamical property of PBPTs,and has good stability and great prediction ability. 相似文献
67.
We report an all-fiber mode-locked erbium-doped fiber laser (EDFL) employing carbon nanotube (CNT) polymer composite film. By using only standard telecom grade components, without any complex polarization control elements in the laser cavity, we have demonstrated polarization locked vector solitons generation with duration of ~583 fs, average power of ~3 mW (pulse energy of 118 pJ) at the repetition rate of ~25.7 MHz. 相似文献
68.
Yuanyi Cao Shaolei Wang Haiyan Mou Haiyan Xu Chifei Wu 《Journal of Crystal Growth》2010,312(10):1747-1750
Crystal growth of a hindered phenol compound, tetrakis [methylene-3-(3-5-ditert-butyl-4-hydroxy phenyl) propionyloxy] methane (trade name AO-60), was successfully recorded by optical microscopy (OM) equipped with a hot stage. The morphology of AO-60 crystals, grown at 100 °C from amorphous state, appeared in the form of tetragonal-sloped step growth. Further study using scanning electron microscopy (SEM) and atomic force microscopy (AFM) experimentally demonstrated that AO-60 crystals had a hopper-like morphology, which had occurred rarely in the condition of organic compound crystals but predominantly rather to inorganic compound crystals in the reported literatures. The morphological features observed on the crystal surfaces suggested step growth and hopper growth mechanism. Besides, a raising around the edge of the AO-60 hopper crystal was also experimentally characterized for the first time. 相似文献
69.
Xue Jing Yanga Ya Ling Yang Wei Zhenb Mou Sheng Liua Jun Hong Chaia a Faculty of Life Science Technology Kunming University of Science Technology Kunming China b Kunming Fruit Business Economics Co.Ltd. Kunming China 《中国化学快报》2009,20(4)
An modified laminar crystal sodium silicate(A1-SKS-6) was synthesized by spray drying and high temperature crystallization using sodium silicate as silicon source,Al atom as inorganic source and hexadecyltrimethy ammonium bromide(CTMAB) as the structure template.The hydrothermal stability of product was at least 1 h.The synthesized material was characterized by XRD and SEM.The results indicated that shape and intensity of XRD diffraction peak at 2θtook changes,but raw materialδphase crystal form kept unc... 相似文献
70.
Wen-Bao Chang Yi-Bing Zhao Yun-Xiang Ci Lin-Yun Hu 《Fresenius' Journal of Analytical Chemistry》1992,344(3):128-130
Summary A rapid fluorimetric method employing the complexes of Al3+ with tetracycline (TC) and anhydrotetracycline (ATC) has been used for the measurement of the concentrations of TC and ATC in about 10–7–10–6 mol/l. The assay offers simplicity and rapidly compared with other methods. The recoveries in the determination of synthetic samples are in the range of 95–103% for TC and 101–120% for ATC. Several determinations of TC and ATC in serum and urine have been carried out with satisfactory results. 相似文献