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941.
In Soo Kim 《Applied Surface Science》2009,255(7):4011-4014
Ag-doped ZnO (ZnO:Ag) thin films were grown on glass substrates by E-beam evaporation technique. The structural, electrical and optical properties of the films were investigated as a function of annealing temperature. The films were subjected to post annealing at different temperatures in the range of 350-650 °C in an air ambient. All the as grown and annealed films at temperature of 350 °C showed p-type conduction. The films lost p-type conduction after post annealing treatment temperature of above 350 °C, suggesting a narrow post annealing temperature window for the fabrication of p-type ZnO:Ag films. ZnO:Ag film annealed at 350 °C revealed lowest resistivity of 7.25 × 10−2 Ω cm with hole concentration and mobility of 5.09 × 1019 cm−3 and 1.69 cm2/V s, respectively. Observation of a free-to-neutral-acceptor (e,Ao) and donor-acceptor-pair (DAP) emissions in the low temperature photoluminescence measurement confirms p-type conduction in the ZnO:Ag films. 相似文献
942.
This contribution demonstrates a synthesis of comb polymer consisting of a poly(epichlorohydrin) (PECH) backbone and poly(oxyethylene
methacrylate) side chains. Atom transfer radical polymerization (ATRP) was used to directly initiate the chlorine atoms of
PECH macroinitiator. The structure of comb polymer was characterized by nuclear magnetic resonance (1H nuclear magnetic resonance) and Fourier transform infrared (FT-IR) spectroscopy, presenting the successful “grafting from”
method using ATRP. The comb polymer was used as a polymer matrix for dissolving potassium iodide (KI) to prepare solid polymer
electrolyte. FT-IR spectroscopy indicates that the potassium salts are dissolved in the polymeric matrix due to coordination
interaction with the ether oxygens of graft copolymer. Differential scanning calorimetry showed that glass transition temperature
(T
g) of polymer electrolytes continuously increased with increasing salt concentration up to 15 wt.%, mostly due to coordinative
interactions between the potassium ions and the ether oxygens of polymer matrix. Ionic conductivity at room temperature increased
with increasing salt concentrations up to 5 wt.% (maximum ionic conductivity ~3.7 × 10−5 S/cm), after which it gradually decreased. 相似文献
943.
In‐Gyung Oh Jong‐Ha Choi Woo‐Taik Lim Ki‐Min Park 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(6):m238-m240
In the title compound, [Cr(ONO)2(cyclam)]NO2 (cyclam is 1,4,8,11‐tetraazacyclotetradecane, C10H24N2), the complex cation is located on a twofold symmetry axis. The central Cr atom has a distorted octahedral coordination, involving two Cr—O bonds, with the monodentate nitrite O atoms adopting a cis configuration, and four Cr—N bonds. The mean Cr—N and Cr—O distances are 2.0895 (14) and 1.9698 (14) Å. 相似文献
944.
A new chiral stationary phase (CSP) containing thioester linkages was prepared by bonding (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid to mercaptopropylsilica gel. The chiral recognition ability of the new CSP was found to be greater than that of the previously reported CSP containing amide linkages in the resolution of the various α-amino acids that were tested, except for that of Met, Ser and Thr. In the resolution of racemic amines and amino alcohols, the new CSP was always better than the one containing amide linkages in terms of the separation factors (α) and the resolutions (RS). Given the identical elution orders on the two CSPs, it was concluded that the chiral recognition mechanism is not affected by the change of the linkage type. In addition, the new CSP was found to be quite stable under the acidic mobile phase conditions that were utilized, indicating that the thioester linkage is useful as a tethering group. 相似文献
945.
Anacardic acid, separated from cashew nut shell liquid, is well known for its strong antibiotic and antioxidant activities.
Recent findings indicate that phenolic compounds from plant sources have an effect on Gram-negative bacteria biofilm formation.
In this work, a polyphenolic coating was prepared from anacardic acid using enzymatic synthesis and tested for its effects
on biofilm formation of both Gram-negative and Gram-positive bacteria. Natural anacardic acid was enzymatically polymerized
using soybean peroxidase. Hydrogen peroxide and phenothiazine-10-propionic acid were used as an oxidizing agent and redox
mediator, respectively. Nuclear magnetic resonance and Fourier transform infrared (FTIR) analyses showed the formation of
oxyphenylene and phenylene units through the phenol rings. No linkage through the alkyl chain was observed, which proved a
high chemo-selectivity of the enzyme. Aqueous solvents turned out to play an important role in the polymer production yield
and molecular weight. With 2-propanol, the highest production yield (61%) of polymer (molecular weight = 3,900) was observed,
and with methanol, higher-molecular-weight polymers (5,000) were produced with lower production yields (43%). The resulting
polyanacardic acid was cross-linked on a solid surface to form a permanent natural polymer coating. The FTIR analysis indicates
that the cross-linking between the polymers took place through the unsaturated alkyl side chains. The polyanacardic acid coating
was then tested for its antibiofouling effect against Gram-negative and Gram-positive bacteria and compared with the antibiofouling
effects of polycardanol coatings reported in the literature. The polyanacardic acid coating showed more reduction in biofilm
formation on its surface than polycardanol coatings in the case of Gram-positive bacteria, while in the case of Gram-negative
bacteria, it showed a similar reduction in biofilm formation as polycardanol. 相似文献
946.
Polycarbonate/epoxy/silica hybrid films were prepared by curing an epoxy reaction via in situ sol–gel process. The influence
of the synthetic conditions, such as the ratio of different epoxy reagents and the contents of [2-(3,4-epoxycyclohexyl)ethyl]trimethoxysilane
on the physical and optical properties of these hybrid films were investigated in details. The coefficient of thermal expansion,
surface roughness, and light transmittance at a wavelength range from 250 to 800 nm were measured. These excellent overall
performances make it a promising photonic packaging material. 相似文献
947.
Maiko Kitajima Marika Miura Naoki Nanashima Toshiko Tomisawa Shizuka Takamagi Miyuki Fujioka Naoya In Tomohiro Osanai 《Molecules (Basel, Switzerland)》2021,26(17)
Lindera umbellata (Lu) essential oil primarily contains linalool and has relaxation properties. We investigated the psychological and antibacterial effects of footbath with Lu essential oil. The participants included 20 women without medical history and received two intervention plans: footbath without any essential oil and footbath using Lu essential oil. Next, questionnaires regarding impressions and mood states were provided for them to answer. In addition, their autonomic nervous system activity was measured, and the aerobic viable of count on the feet was determined. The high-frequency value reflecting the parasympathetic nervous system activity significantly increased after footbath using Lu essential oil. In the questionnaire about the mood states, the subscale scores of tension–anxiety, depression, fatigue, and confusion after intervention were lower than those before intervention regardless of the use of the essential oil. Conversely, the anger–hostility score decreased only in the group using Lu essential oil. Furthermore, the decrease in aerobic viable count after intervention was not significantly different between the two groups. Footbath using Lu essential oil increased the parasympathetic nervous system activity and relieved anger. Taken together, we suggest that footbath using Lu essential oil has a relaxation effect. 相似文献
948.
Melecchi MI Péres VF Dariva C Zini CA Abad FC Martinez MM Caramão EB 《Ultrasonics sonochemistry》2006,13(3):242-250
The influence of several experimental parameters on the ultrasonic extraction of Hibiscus tiliaceus L. flowers were investigated: extraction time, solvent polarity, sample amount, solvent volume and sample particle size. It was concluded that the most influential variables were extraction time and solvent polarity. The optimized procedure employed 5 g of ground flowers, 150 mL of methanol and 140 min of extraction. The extracts were fractionated using preparative silica columns and the resulting fractions were analyzed by GC/MS. Some saturated hydrocarbons, fatty acids, fatty acid methyl esters, phytosterols, and vitamin E were identified in the plant extracts. 相似文献
949.
950.
In Min Hwang Eun Woo Moon Hae-Won Lee Nargis Jamila Kyong Su Kim Ji-Hyoung Ha 《Analytical letters》2019,52(6):932-947
This study investigated the content of macronutrients (Ca, K, Mg, Na, P, and S), trace elements (Ba, Be, Co, Cr, Cu, Fe, Ga, Li, Mn, Ni, Rb, Se, Sr, V, and Zn), and trace toxic elements (As, Cd, In, Pb, and Tl) in chili powder from Korea, China, and Vietnam. For the analyses, inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectroscopy (ICP-OES) were used. In addition, near-infrared (NIR) spectroscopy was used to differentiate functional groups based on the chemical constituents. For the validation of the applied analytical methods, good linearity (coefficients of determination, 0.9443–0.99997), and relative standard deviations below 4% were obtained. The contents of the toxic elements were below the provisional tolerable weekly intake values. Linear discriminant analysis using elemental contents and NIR data was performed to establish and authenticate the geographical origin of chili powder, which confirmed the reliability of the obtained results. 相似文献