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1.
Ramesh Pratibha Nalini Larysa Khomenkova Olivier Debieu Julien Cardin Christian Dufour Marzia Carrada Fabrice Gourbilleau 《Nanoscale research letters》2012,7(1):124
Microstructural, electrical, and optical properties of undoped and Nd3+-doped SiO
x
/SiN
y
multilayers fabricated by reactive radio frequency magnetron co-sputtering have been investigated with regard to thermal
treatment. This letter demonstrates the advantages of using SiN
y
as the alternating sublayer instead of SiO2. A high density of silicon nanoclusters of the order 1019 nc/cm3 is achieved in the SiO
x
sublayers. Enhanced conductivity, emission, and absorption are attained at low thermal budget, which are promising for photovoltaic
applications. Furthermore, the enhancement of Nd3+ emission in these multilayers in comparison with the SiO
x
/SiO2 counterparts offers promising future photonic applications. 相似文献
2.
The optimum conditions for synthesizing LiNi1-y
Co
y
O2 (y=0.1, 0.3 and 0.5) by a simplified combustion method, in which the preheating step is omitted, and the electrochemical properties
of these materials were investigated. The optimum condition for synthesizing LiNi0.9Co0.1O2 by the simplified combustion method is calcination at 800 °C for 12 h in air in 3.6 mole ratio of urea to nitrate. The LiNi0.9Co0.1O2 synthesized under these conditions shows the smallest R-factor{(I
006+I
102)/I
101} and the largest I
003/I
104, indicating better hexagonal ordering and less cation mixing, respectively. The LiNi0.7Co0.3O2 synthesized at 800 °C for 12 h in air in 3.6 mole ratio of urea to nitrate has the largest first discharge capacity 156.2 mA h g−1 at 0.5C and shows relatively good cycling performance. This sample shows better hexagonal ordering and less cation mixing
than the other samples. The particle size of the LiNi0.7Co0.3O2 is relatively small and its particles are spherical with uniform particle size. 相似文献
3.
This study investigated the toxicity of Cu (1, 10, 15, and 25 mol%) loaded TiO2 and pure TiO2 nanometersized photocatalysts during the development of zebrafish embryogenesis. The hatch rate decreased in the Cu
x
TiO
y
nanoparticles exposed groups (10, 20 ppt) compared to pure TiO2 nano-particles (10, 20 ppt) exposed or control groups. These Cu
x
TiO
y
and TiO2 nanoparticles led to developing mutated embryos with abnormal notochord formation, no tail, damaged eyes and abnormal heart
development. Exposure to Cu
x
TiO
y
and pure TiO2 nanoparticles led to glutathione increase, catalase activity increase, GST increase and GSR increase than control. Penetration
of the Cu
x
TiO
y
and pure TiO2 nanoparticles to the embryo was also tested. It was observed that Cu
x
TiO
y
and pure TiO2 nanoparticles penetrated into cells. Moreover Cu
x
TiO
y
penetrated into the skin, nerve and yolk sac epithelium cells on the zebrafish larvae as aggregated particles, which may
induce the direct interaction between nanoparticles and cell to cause adverse biological responses. As a result, the Cu-loaded
TiO2 nanoparticles had the toxicity of zebrafish embryo and larvae in the water environment. 相似文献
4.
We examined and compared the electrical properties of silica (SiO2) and silicon oxynitride (SiO
x
N
y
) layers embedding silicon nanoclusters (Sinc) integrated in metal-insulator-semiconductor (MIS) devices. The technique used
for the deposition of such layers is the reactive magnetron sputtering of a pure SiO2 target under a mixture of hydrogen/argon plasma in which nitrogen is incorporated in the case of SiO
x
N
y
layer. Al/SiO
x
N
y
-Sinc/p-Si and Al/SiO2-Sinc/p-Si devices were fabricated and electrically characterized. Results showed a high rectification ratio (>104) for the SiO
x
N
y
-based device and a resistive behavior when nitrogen was not incorporating (SiO2-based device). For rectifier devices, the ideality factor depends on the SiO
x
N
y
layer thickness. The conduction mechanisms of both MIS diode structures were studied by analyzing thermal and bias dependences
of the carriers transport in relation with the nitrogen content. 相似文献
5.
Evidence suggests that minor isomers of conjugated linoleic acid (CLA), such as trans8, cis10 CLA, can elicit unique biological effects of their own. In order to determine the effect of a mixture of t8, c10+c9, t11 CLA isomers on selected aspects of lipid metabolism, 3T3-L1 preadipocytes were differentiated for 8 days in the presence
of 100 μM linoleic acid (LA); t8, c10+c9, t11 CLA; t10, c12+c9, t11 CLA or purified c9, t11 CLA. Whereas supplementation with c9, t11 and t10, c12+c9, t11 CLA resulted in cellular triglyceride (TG) concentrations of 3.4 ± 0.26 and 1.3 ± 0.11 μg TG/μg protein, respectively (P < 0.05), TG accumulation following treatment with CLA mixture t8, c10+c9, t11 was significantly intermediate (2.5 ± 0.22 μg TG/μg protein, P < 0.05) between the two other CLA treatments. However, these effects were not attributable to an alteration of the Δ9 desaturation index. Adiponectin content of adipocytes treated with t8, c10+c9, t11 mixture was similar to the individual isomer c9, t11 CLA, and both the t8, c10+c9, t11 and c9, t11 CLA groups were greater (P < 0.05) than in the t10, c12+c9, t11 CLA group. Overall, these results suggest that t8, c10+c9, t11 CLA mixture affects TG accumulation in 3T3-L1 cells differently from the c9, t11 and t10, c12 isomers. Furthermore, the reductions in TG accumulation occur without adversely affecting the adiponectin content of these
cells. 相似文献
6.
A new version of the STRUCTON-1.2 computer program (2009) has been presented. The program combines the algorithm for calculating
real distributions of Q
n
structons in binary silicate melts (with allowance made for their disproportionation) and the statistical simulation of molecular-mass
distributions of polymerized ions at different temperatures. This model has been used to perform test calculations for two
melts in the Na2O-SiO2 system (Na6Si2O7, Na6Si3O9). The results of the calculations have made it possible to trace variations in the set and concentrations of chain and ring
silicon-oxygen complexes with a decrease in the temperature in the order: stochastic molecular-mass → distribution molecular-mass
distribution at T = 2000 K → molecular-mass distribution at the liquidus temperature. The main result of these calculations is that the dominant
species of silicon-oxygen anions at the liquidus temperatures (in contrast to the stochastic distributions) exactly correspond
to the stoichiometry of the initial melts: the Si2O76− chain anions and (Si
n
O3n
)3n− ring complexes are dominant in the Na6Si2O7 and Na6Si3O9 melts, respectively. It has been established that, with a decrease in the temperature, the average size of polymer complexes
varies weakly in the Na6Si2O7 melt but increases by a factor of approximately 1.5 in the metasilicate system. 相似文献
7.
Derivatives of 2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropanecarboxylic acid (chrysanthemic acid) are classic natural pyrethroids discovered in pyrethrum plants and show insecticidal activity. Chrysanthemic acid, with two asymmetric carbons, has four possible stereoisomers, and most natural pyrethroids have the (1R,3R)-trans configuration. Interestingly, chrysanthemic acid–related structures are also found in insect sex pheromones; carboxylic esters of (1R,3R)-trans-(2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropyl)methanol (chrysanthemyl alcohol) have been reported from two mealybug species. In the present study, another ester of chrysanthemyl alcohol was discovered from the striped mealybug, Ferrisia virgata (Cockerell), as its pheromone. By means of gas chromatography–mass spectrometry, nuclear magnetic resonance spectrometry, and high-performance liquid chromatography analyses using a chiral stationary phase column and authentic standards, the pheromone was identified as (1S,3R)-(?)-cis-chrysanthemyl tiglate. The (1S,3R)-enantiomer strongly attracted adult males in a greenhouse trapping bioassay, whereas the other enantiomers showed only weak activity. The cis configuration of the chrysanthemic acid–related structure appears to be relatively scarce in nature, and this is the first example reported from arthropods. 相似文献
8.
The possibility of the substitution Bi → Ln occurring in the Bi3TaTiO9 Aurivillius phases has been studied for the first time. The Bi2LaTaTiO9, Bi2NdTaTiO9, Bi2SmTaTiO9, and Bi2GdTaTiO9 compounds have been synthesized according to solid-phase reactions in the temperature range 800–1100°C, and their unit cell
parameters have been determined. 相似文献
9.
E. B. Merkulov N. A. Logoveev V. K. Goncharuk R. M. Yaroshenko 《Glass Physics and Chemistry》2007,33(2):106-108
The glass formation in the ZrF4-BiF3-MeF (Me = Li, Na, K) systems is investigated. Bismuth fluorozirconate glasses are synthesized in this system, and their thermal and optical properties are described. 相似文献
10.
Regular arrays of Ti
x
Sn1-
x
O2 nanoflakes were fabricated through glancing angle sputter deposition onto self-assembled close-packed arrays of 200-nm-diameter
polystyrene spheres. The morphology of nanostructures could be controlled by simply adjusting the sputtering power of the
Ti target. The reflectance measurements showed that the melon seed-shaped nanoflakes exhibited optimal properties of antireflection
in the entire visible and ultraviolet region. In addition, we determined their anisotropic reflectance in the direction parallel
to the surface of nanoflakes and perpendicular to it, arising from the anisotropic morphology. 相似文献
11.
Ya. V. Mikhailova S. A. Sviderskii A. Yu. Krylova A. L. Lapidus 《Solid Fuel Chemistry》2010,44(5):345-350
The 20% Co-M/CoAl
x
O
y
catalytic systems promoted with Ru, Pd, and Re, in which cobalt is not only an active component but also a constituent of
the support, were studied in this work. The effects of the addition and concentration of a promoter on the catalytic properties
of the resulting system in the synthesis of hydrocarbons from CO and H2 was studied. It was found that the introduction of rhenium into the composition of the 20% Co/CoAl
x
O
y
catalyst considerably increased the yield of C5+ hydrocarbons with a minimum methane formation in the synthesis of hydrocarbons from CO and H2. 相似文献
12.
The hydrocarbons (3Z,6Z,9Z)-3,6,9-octadecatriene (3Z,6Z,9Z-18:H) and (3Z,6Z,9Z)-3,6,9-nonadecatriene (3Z,6Z,9Z-19:H) constitute the pheromone of the winter moth, Erannis bajaria. These compounds belong to a large group of lepidopteran pheromones which consist of unsaturated hydrocarbons and their corresponding
oxygenated derivatives. The biosynthesis of such hydrocarbons with an odd number of carbons in the chain is well understood.
In contrast, knowledge about the biosynthesis of even numbered derivatives is lacking. We investigated the biosynthesis of
3Z,6Z,9Z-18:H by applying deuterium-labeled precursors to females of E. bajaria followed by gas chromatography–mass spectrometry analysis of extracts of the pheromone gland. A mixture of deuterium-labeled
[17,17,18,18-2H4]-3Z,6Z,9Z-18:H and the unlabeled 3Z,6Z,9Z-18:H was obtained after topical application and injection of (10Z,13Z,16Z)-[2,2,3,3-2H4]-10,13,16-nonadecatrienoic acid ([2,2,3,3-2H4]-10Z,13Z,16Z-19:acid) or (11Z,14Z,17Z)-[3,3,4,4-2H4]-11,14,17-icosatrienoic acid ([3,3,4,4-2H4]-11Z,14Z,17Z-20:acid). These results are consistent with a biosynthetic pathway that starts with α-linolenic acid (9Z,12Z,15Z-18:acid). Chain elongation leads to 11Z,14Z,17Z-20:acid, which is shortened by α-oxidation as the key step to yield 10Z,13Z,16Z-19:acid. This acid can be finally reduced to an aldehyde and decarbonylated or decarboxylated to furnish the pheromone component
3Z,6Z,9Z-18:H. A similar transformation of 11Z,14Z,17Z-20:acid yields the second pheromone component, 3Z,6Z,9Z-19:H. 相似文献
13.
J.-F. Butaud P. Raharivelomanana J.-P. Bianchini E. M. Gaydou 《Journal of the American Oil Chemists' Society》2008,85(4):353-356
The sandalwood kernels of Santalum insulare (Santalaceae) collected in French Polynesia give seed oils containing significant amounts of ximenynic acid, E-11-octadecen-9-oic acid (64–86%). Fatty acid (FA) identifications were performed by gas chromatography/mass spectrometry
(GC/MS) of FA methyl esters. Among the other main eight identified fatty acids, oleic acid was found at a 7–28% level. The
content in stearolic acid, octadec-9-ynoic acid, was low (0.7–3.0%). An inverse relationship was demonstrated between ximenynic
acid and oleic acid using 20 seed oils. Results obtained have been compared to other previously published data on species
belonging to the Santalum genus, using multivariate statistical analysis. The relative FA S. insulare composition, rich in ximenynic acid is in the same order of those given for S. album or S. obtusifolium. The other compared species (S. acuminatum, S. lanceolatum, S. spicatum and S. murrayanum) are richer in oleic acid (40–59%) with some little differences in linolenic content. 相似文献
14.
B. I. Galagan L. N. Dmitruk L. V. Moiseeva V. V. Osiko M. N. Brekhovskikh V. A. Fedorov 《Glass Physics and Chemistry》2007,33(2):136-139
The glass formation and crystallization of ErI3-doped melts in the Ag-Cs-Pb-X (X = I, Br, Cl) are investigated in the section corresponding to the cation ratio Ag: Cs: Pb = 59: 39: 2 with ErI3 contents of 0.2–7.5 mol %. The glass transition, crystallization, and melting temperatures are determined for a number of compositions. The primary crystalline phases that precipitate from melts upon crystallization are identified. It is demonstrated that the iodide, bromide, and chloride glasses containing up to 0.5 mol % ErI3 have the lowest crystallization ability. An increase in the ErI3 content leads to the precipitation of unidentified erbium-containing phases from melts upon cooling and to an increase in the crystallization ability of glasses. The spectral and luminescence properties of the glass of the composition 52Ag · 17AgCl · 39CsBr · 2PbCl2 + 0.5 mol % ErI3 are studied in the range of the 4 I 13/2 → 4 I 15/2 transition of the Er3+ ion. It is found that the lifetime of the 4 I 13/2 → 4 I 15/2 level of the Er3+ ion is equal to 10 ms. 相似文献
15.
The objective of the present study was to compare the effects of cis-9,trans-11 + trans-8,cis-10 conjugated linoleic acid (CLA) mixture to those of cis-9,trans-11 + trans-10,cis-12 CLA mixture and linoleic acid (LA) on lipoprotein profile, hepatic lipids, body composition and digestibility of dietary
fat in hamsters (n = 17) fed diets containing 2% of experimental fat (w/w) for 28 days. The cis-9,trans-11 + trans-10,cis-12 CLA mixture showed higher LDL cholesterol concentrations than LA and the cis-9,trans-11 + trans-8,cis-10 CLA mixture. The cis-9,trans-11 + trans-8,cis-10 CLA mixture induced similar plasma LDL cholesterol and hepatic lipid concentrations, and coefficient of digestibility
as LA, indicating no effect of the trans-8,cis-10 CLA isomer on these lipid parameters. On the other hand, the cis-9,trans-11 + trans-8,cis-10 CLA mixture induced higher plasma VLDL cholesterol and triglycerides than LA and the cis-9,trans-11 + trans-10,cis-12 CLA mixture. The cis-9,trans-11 + trans-8,cis-10 CLA mixture also induced the highest plasma glucose concentrations compared with the two other groups, indicating an impairment
of glycemic control. No differences in body composition were noted between the three groups. The present results thus show
that the cis-9,trans-11 + trans-8,cis-10 CLA mixture can deteriorate plasma VLDL cholesterol and triglycerides in hamsters, possibly due to an increased flux of
glucose. 相似文献
16.
In this study, we synthesized the new kinds of semiconducting polymeric gels having negative (n-type) and positive (p-type) counter ions as charge carriers. The polyacrylamide gel was doped with pyranine (8-hydroxypyrene-1,3,6-trisulfonic
acid, trisodium salt), having
\textSO3 - {\text{SO}}_{3}^{ - } ions as side groups and Na+ as counter ions, so-called p-type semiconducting gel. The doping process was performed during the polymerization where the pyranine binds to the polymer
strands over OH group chemically via radical addition. In a similar way, N-isopropylacrylamide (NIPA) gel was doped with methacrylamidopropyltrimethyl
ammonium chloride (MAPTAC), having Cl− as counter ions, so-called n-type semiconducting gel. Here MAPTAC was embedded by copolymerization within the polymer network (NIPA). These semiconducting
gels can show different electrical properties by changing the concentration of the doping agents, swelling ratio etc. We have
shown that the pn junction, formed by combining p-type and n-type gels together in close contact, rectifies the current similar to the conventional Si and Ge diodes. 相似文献
17.
Malpuech-Brugère C Mensink RP Loreau O Maret A Fernie CE Lassel TS Chardigny JM Scrimgeour CM Sébédio JL Beaufrère B 《Lipids》2010,45(11):1047-1051
Few studies report the individual effect of 9c,11t- and 10t,12c-CLA on human energy metabolism. We compared the postprandial oxidative metabolism of 9c,11t- and 10t,12c-CLA and oleic acid (9c-18:1) in 22 healthy moderately overweight volunteers. After 24 weeks supplementation with 9c,11t-, 10t,12c-CLA or 9c-18:1 (3 g/day), subjects consumed a single oral bolus of the appropriate [1-13C]-labeled fatty acid. 8 h post-dose, cumulative oxidation was similar for 9c-18:1 and 10t,12c (P = 0.66), but significantly higher for 9c,11t (P < 0.01). 相似文献
18.
The autoxidation processes of the cis-9,trans-11 (c9,t11) and trans-10,cis-12 (t10,c12) isomers of CLA were separately observed at ca. 0% RH and different temperatures. The t10,c12 CLA oxidized faster than the c9,t11 isomer at all tested temperatures. The first half of the oxidation process of t10,c12 CLA obeyed an autocatalytic-type rate expression, but the latter half followed first-order kinetics. On the other hand,
the entire oxidation process of c9,t11 CLA could be expressed by the autocatalytic-type rate expression. The apparent activation energies and frequency factors
for the autoxidation of the isomers were estimated from the rate constants obtained at various temperatures based on the Arrhenius
equation. The apparent activation energies for the CLA isomers were greater than those for the nonconjugated n−6 and n−3 PUFA
or their esters. However, the enthalpyentropy compensation held during the autoxidation of both the CLA and PUFA. This suggested
that the autoxidation mechanisms for the CLA and PUFA were essentially the same. 相似文献
19.
Yongchao Lai Weiwei Yin Jinting Liu Rimo Xi Jinhua Zhan 《Nanoscale research letters》2010,5(2):302-307
Water-soluble l-arginine-capped Fe3O4 nanoparticles were synthesized using a one-pot and green method. Nontoxic, renewable and inexpensive reagents including FeCl3, l-arginine, glycerol and water were chosen as raw materials. Fe3O4 nanoparticles show different dispersive states in acidic and alkaline solutions for the two distinct forms of surface binding
l-arginine. Powder X-ray diffraction and X-ray photoelectron spectroscopy were used to identify the structure of Fe3O4 nanocrystals. The products behave like superparamagnetism at room temperature with saturation magnetization of 49.9 emu g−1 and negligible remanence or coercivity. In the presence of 1-ethyl-3-(dimethylaminopropyl) carbodiimide hydrochloride, the
anti-chloramphenicol monoclonal antibodies were connected to the l-arginine-capped magnetite nanoparticles. The as-prepared conjugates could be used in immunomagnetic assay. 相似文献
20.
Sun-Wook Jeong Jung Eun Yang Seonghun Im Yong Jun Choi 《Korean Journal of Chemical Engineering》2017,34(6):1728-1733
The extremophilic bacterium Deinococcus radiodurans R1 has been considered as an attractive microorganism due to its remarkable tolerance to various external stresses. Considering the nature of D. radiodurans R1, it has potential as a platform microorganism for industrial applications, including biorefinery and bioremediation process. However, D. radiodurans R1 is well known for its hard genetic manipulation. Thus, much effort has been made to develop efficient genetic engineering tools for making D. radiodurans R1 suitable for industrial platform microorganism. Although a plasmid-based single gene knockout method has been reported, development of multiple gene knockout system has not yet been reported. Here we report, for the first time, Cre-lox based rapid and efficient multiple knockout method for metabolic engineering of D. radiodurans R1. Also, deletion of dr0053 gene was successfully achieved within seven days to make biofilm overproducing strain. 相似文献