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1.
A practical catalytic method to oxidize α-ionone with molecular oxygen using N-hydroxyphthalimide(NHPI) combined with acetylacetone
cobatt(II) (Co(acac)2) was developed, and the probable catalytic mechanism was proposed. The influences of the reaction conditions on conversion
of α-ionone and the selectivity of the major product (5-keto-α-ionone) were investigated, and the technical parameters for
5-keto-α-ionone were optimized. The results show that the primary product is 5-keto-α-ionone, and by-products include epoxy-α-ionone,
as well as rearrangement products 4-keto-β-ionone and epoxy-β-ionone, which are characterized by infrared spectra, proton
nuclear magnetic resonance spectra, mass spectra and elemental analysis. The selectivity of 5-keto-α-ionone and the conversion
of α-ionone are 55.0% and 97.0%, respectively, when 30%(molar fraction) NHPI, 1.0%(molar fraction) Co(acac)2 and no solvent are employed under O2 pressure of 1.0 MPa and the reaction temperature of 65 °C for 11 h. The procedure shows good reproducibility in the parallel
experiments.
Foundation item: Project(50573019) supported by the National Natural Science Foundation of China 相似文献
2.
1INTRODUCTION Themagneticmetal coatedceramicoxides,core shellstructuralcompositematerials,inwhichthinmetallicfilmsarecoatedonaceramicoxide matrixwithmicrometerparticlesizes,areattrac tiveduetothecombinationofthefunctionalchar acteristicsofmetalsandmechanicalpropertiesoftheceramicmatrix.Theceramic basedtransition metal coated,core shellcompositessuchasNi coatedAl2O3[1],Fe coatedAl2O3[2],FeNi coated Al2O3[3]orCoFe coatedSiO2[4],havebeenfoundtoexhibitinterestingfunctionalperformancesdue… 相似文献
3.
A novel way for photo-immobilization with interferon- α (IFN- α) on the surface of polyurethane (PU) material, which makes PU condom more effective function in the future, was investigated.
A kind of photoactive arylazide-4-azidobenzoic acid was modified to IFN- α with the confirmation of IR and Raman spectrum. Micro morphology of the photo-immobilized cell factors was observed by FESEM
as well as CSLM at the level of nanometer. Finally, the product with elementary test of anti-microbial was also evaluated.
Funded by the Guangdong Technology Projects (No.2006B35802003), the Natural Science Foundation of Guangdong Province (No.8451063101000345)
and the Opening Project of MOE Key laboratory of Laser Life Science, South China Normal University, Guangzhou 510631, China 相似文献
4.
Single crystal β-Ga2O3: Cr grown by floating zone technique and its optical properties 总被引:1,自引:0,他引:1
β-Ga2O3 Cr single crystals were grown by floating zone technique. Absorption spectra and fluorescence spectra were measured at room temperature. The values of field splitting parameter Dq and Racah parameter B were obtained by the peak values of absorption spectra. The value 10Dq/B=23.14 manifests that in -Ga2O3 crystals Cr3 ions are influenced by low energy crystal field. After high temperature annealing in air, the Cr3 intrinsic emission was enhanced and the green luminescence disappeared. The strong and broad 691 nm emission was obtained at 420 nm excitation due to the electron transition occurred from 4T2 to 4A2. The studies manifest that the β-Ga2O3 crystals have the potential application for tunable laser. 相似文献
5.
The chiral separation of phenylsuccinic acid (PSA) was studied by reversed phase high-performance liquid chromatography (RP-HPLC)
with cyclodextrins (CDs) as chiral mobile phase additives. The effects of types of CDs, concentration of hydroxypropyl-β-cyclodextrin (HP-β-CD), percentage of organic modifier, pH value and column temperature on enantioselective separation were investigated. The
quantification property of the developed RP-HPLC method was examined. The chiral recognition mechanism of PSA was also discussed.
The results show that a baseline separation of PSA enantiomers is achieved on a Lichrospher C18 column (4.6 mm (inner diameter)×250
mm, 5 μm) with HP-β-CD as chiral mobile phase additive. The capacity factors of R-PSA and S-PSA are 3.94 and 4.80, respectively. The separation factor and resolution are respectively 1.22 and 8.03. The mobile phase
is a mixture of acetonitrile and deionized water (20:80, volume ratio) containing 10 mmol/L HP-β-CD and 0.05% trifluoroacetic acid (pH 2.5, adjusted with triethylamine) with a flow rate of 1.0 mL/min. The ultraviolet (UV)
detector is set at 254 nm. The likely roles are inclusion interaction, induction and hydrogen bonding between HP-β-CD and PSA enantiomers.
Foundation item: Project(20776038) supported by the National Natural Science Foundation of China 相似文献
6.
王子明 《武汉理工大学学报(材料科学英文版)》2007,22(2):337-340
The chemical structures of four types of superplasticizers (SPs) and their adsorptive behaviors on β-C2S were investigated. The adsorption properties of SPs on β-C2S were measured and the relationship between the adsorption quantity and the specific surface of β-C2S was analyzed. The experimental results show that the adsorption quantity increases with the surface area increase of β-C2S, but the adsorption quantity per surface area is similar, which means that the main adsorbent is β-C2S itself. Polycarboxylic ester (PCE) showed the highest adsorption amount on β-C2S, followed by β-naphthalene sulfonates (NSF) and formaldehyde-acetone condensates sulfonates (FAS), amino sulphonate (AS) showed the least adsorption amount on β-C2S. PCE affected the surface potential of β-C2S particles in water differently in comparison with other types of SPs. The adsorption capacity of SPs on β-C2S is determined by factors such as molecular structure, functional groups and molecular weight of SPs. 相似文献
7.
Ammonium aluminum carbonate hydroxide (AACH) precursor was synthesized by the precipitation reaction of aluminum sulfate and ammonium carbonate. Then the precursor was dealt with five drying methods including ordinary drying, alcohol exchange, vacuum freeze-drying, glycol distillation, n-butanol azeotropic distillation respectively and calcined at 1 200℃ for 2 h to get α-Al2O3. The effects of drying methods on preparation of nanometer α-Al2O3 were discussed, and the optimal drying method was confirmed. The structural properties of powders were characterized by XRD, SEM and BET measurements. The results show that vacuum freeze-drying, glycol distillation and n-butanol azeotropic distillation can prevent the powders from aggregating, and among them the n-butanol azeotropic distillation is the best method. The nanometer α-Al2O3 powder with non-aggregation can be manufactured using n-butanol azeotropic distillation and the average particle size is about 40 nm. 相似文献
8.
1 INTRODUCTIONDuringhotworking ,severalmetallurgicalphenomenasuchaswork hardening (WH ) ,dynamicrecovery (DRV) ,anddynamicre crystallizaiton (DRX )occursimultaneous ly[1 5 ] .Especially ,theoccurrenceofDRX ,canrefinegrainandreducedeformationresistanceinpracticalhot w… 相似文献
9.
17α-actoxy-19-nor-progesterone was synthesized by a new efficient stereoselective asymmertric pathway from 19-nor-androst-4-en-3,
17-dione in 5-steps reactions with overall yield 63.3%. Consequently, a strategy was used to produce of 17-α-hydroxyl compound
stereoselectively by addition 17-keto steroid with hydrogen cyanide, at the same time, the conditions of this asymmertric
reaction were optimized. The titled compound and the intermediate were fully characterized by 1H, one dimension and two dimension 13C-nuclear magnetic resonance, and infrared spectrum. The results show that the rate of 17-α-hydroxyl compound isomeride is
sensitively affected by the solution system and the best volume ratio of CH3OH to H2O is 36%. After the carbonyl and hydroxyl groups were protected by ethylenediol and vinyl butyl ether respectively, organometallic
addition to CN group with CH3Li, androstance compound was converted to pregnane compound. After removing the protective groups by a mild hydrolytic procedure
with high yield, the titled compound was obtained by esterified the above intermidiate. The new pathway gives a good purity
of 98% as determined by high performance liquid chromatography.
Foundation item: Project(20376018) supported by the National Natural Science Foundation of China 相似文献
10.
The precipitation behavior of V(C, N) in steels microalloyed with vanadium was researched using a thermal simulator during single-pass deformation at 800-750 ℃. The V(C, N) precipitates and its nucleation effect on ferrite were investigated by TEM and EDS. The experimental results show that there are two remarkable heterogeneous nucleation effects of V(C, N) particles precipitated before γ →/ α phase change: primary reason is that high coherency between V(C, N) and ferrite promotes V(C, N) to become a nucleating center of intragranular ferrite; secondary reason is that the coarsening of V(C, N) causes locally solute-poor region in austenite, thus expedites the nucleation of intragranular ferrites further. Furthermore, the relationship between the size and shape of V(C, N) was studied, and identification method was provided for distinguishing interphase precipitation and general precipitation to avoid erroneous judgment and misguide. 相似文献