共查询到20条相似文献,搜索用时 15 毫秒
1.
Xiaofeng Zhang Shen Lin Xinqing Chen Jiebo Chen Liuyi Yang Minghong Luo 《Frontiers of Chemistry in China》2007,2(4):419-421
Mesoporous aluminophosphate was prepared by using G4.0 poly(amido amine)dendrimer as a template and characterized by Fourier
transform infrared spectrometer (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption/desorption methods. Results show that the title compound exhibits a typical mesoporous structure with the average
pore size from 5 to 8 nm. The formation mechanism of the nanoporous structure using dendrimer as a template was also discussed.
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Translated from Journal of Fujian Normal University (Natural Science Edition), 2007, 23(2): 67–70 [译自: 福建师范大学学报 (自然科学版)] 相似文献
2.
The electrochemical behavior of ciprofloxacin (CFX) and its interaction with the natural calf thymus DNA (ctDNA) is studied
by using pulse difference voltammetry on a carbon electrode. CFX shows a well-defined oxidative peak at + 0.88 V. As a result
of reaction with ctDNA,the oxidative peak of CFX decreased markedly. According to the electrochemical equation deduced in
this paper, the binding constant of 1.36 × 105 (mol/L)−1 and the binding size of 1.94 (base pairs) of CFX with ctDNA were obtained by nonlinear fit analysis of the electrochemical
data. The mechanism of the interaction was explored.
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Translated from Journal of Zhejiang University (Science Edition), 2007, 34(3): 330–334 [译自: 浙江大学学报(自然科学版)] 相似文献
3.
Haihong Fang Binyuan Hu Lingshen Wang Rongli Lu Cui Yang 《Frontiers of Chemistry in China》2008,3(2):193-197
Nanometer MgO was prepared via a sol-gel auto-combustion technique using magnesium nitrate as raw material and citric acid
as chelating agent. IR spectra of the dried gel were used to investigate the structure of the precursors. By studying the
different TG curves of magnesium citrate gel prepared by different methods, we found that a combustion process occurred and
the nitrate ions acted as an oxidant in the combustion process. TEM photographs of synthesized powders from the sol-gel auto-combustion
showed that the crystallites were uniform in size. In addition, the XRD pattern of this sample showed that the particle size
was 8.9 nm. The BET curves, in turn, showed that the specific surface of the sample was 26.34 m2/g. The mechanism of the frothing process in restraining agglomeration is discussed.
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Translated from Journal of East China Normal University (Natural Science), 2007, (2): 52–57 [译自: 华东师范大学学报(自然科学版)] 相似文献
4.
Huixue Ren Yanzhao Yang Jimao Lin Yinshan Qi Yeqing Zhang 《Frontiers of Chemistry in China》2008,3(2):152-156
A new synthetic method for 5-bromo-3-sec-butyl-6-methyluracil (Bromacil) using 2-bromobutane and urea as starting materials is described. The synthesis involved condensation,
cyclization and bromination with a total yield of 60%. The structure of Bromacil was determined by 1H NMR, 13C NMR and IR spectroscopy.
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Translated from Journal of Shandong University (Natural Science Edition), 2007, 42(7): 9–12 [译自: 山东大学学报(自然科学版)] 相似文献
5.
A nano-alumina with high specific area was prepared using a homogeneous precipitation method with titanium dioxide and barium
oxide as modifying additives. Results showed that 5 wt% TiO2 or BaO added in the alumina gels can decrease the particle size and increase the specific area, but excessive TiO2 or BaO could deteriorate the properties of α-Al2O3.
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Translated from Journal of Shandong University of Technology (Natural Science Edition), 2007, 27(3): 23–26 [译自: 山东理工大学学报(自然科学版)] 相似文献
6.
Lingang Li Yu Tang Yuanming Zhang Jun Yang Biying Du 《Frontiers of Chemistry in China》2008,3(1):76-80
ZnS hollow nanospheres with holes were prepared by reacting ZnSO4 with H2S, the sulfide source formed in the reaction of CS2 with ethylenediamine, 1,3-propylenediamine, butylamine or 2-(2-aminoethylamino) ethanol, which also acted as a template agent,
at 50°C under agitation. The shape, particle size of about 100–850 nm and hole size of about 150–600 nm of ZnS hollow nanospheres
with holes were shown by SEM and TEM images. These ZnS nanospheres with β cubic ZnS phase and composed of 2–5 nm nanocrystals
were characterized by XRD and HRTEM. The blue shift of maximum absorption in UV-vis displayed the effect of quantum size.
The two amino groups of amine templates reacted favorably with Zn2+ to form uniform and relatively smooth ZnS nanospheres with holes, while hydroxyethyl played a disadvantageous role. A reasonable
mechanism of hole formation by H2S rushing out is suggested.
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Translated from Journal of Jinan University (Natural Science), 2007, 28(1): 92–95 [译自: 暨南大学学报(自然科学版)] 相似文献
7.
Chunyue Pan Qingde Long Dian Yu Yanping Rao Nianqian Wu Xingcui Li 《Frontiers of Chemistry in China》2008,3(3):314-319
A series of N-isopropylacrylamide (NIPAAm) copolymer gels with different hydrophilicities were prepared from NIPAAm, hydrophilic acrylamide
(AAm) and hydrophobic butyl methacrylate (BMA). The swelling and thermo-responsive properties of PNIPAAm P (NIPAm-co-BMA)
and P(NIPAm-co-AAm) copolymer hydrogels were investigated. The drug loading and releasing behaviors for two kinds of model drug with different
hydrophilicities were studied. The result shows that the copolymer gels present negative thermo-sensitivities. The lower critical
solution temperature (LCST), equilibrium swelling degree and the initial swelling rate increase as the hydrophilicity of gels
increases when the temperature is below the LCST. With increasing gel hydrophilicity the loading ratio for sodium salicylate
increases, while for salicylic acid, the reverse is observed. The initial drug releasing rate of sodium salicylate and salicylic
acid also increase with increasing gel hydrophilicity. The initial drug releasing rate of sodium salicylate is significantly
higher than that of salicylic acid. For salicylic acid which is less hydrophilic, the equilibrium releasing ratio at high
temperature is lower than that at low temperature while for sodium salicylate which is more hydrophilic, the equilibrium releasing
ratio at high temperature is almost the same as that at low temperature. Equilibrium releasing ratios of the three gels are
significantly different from each other for salicylic acid when the temperature is below LCST while the equilibrium releasing
ratios of the three gels are all 100% for sodium salicylate.
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Translated from Journal of Central South University (Science and Technology), 2007, 38(5): 906–911 [译自: 中南大学学报(自然科学版)] 相似文献
8.
Xiaolei Zhang Mingwang Pan Shengnan Xing Jingsheng Li 《Frontiers of Chemistry in China》2008,3(1):27-32
An ionomer-type of polyurethane (PU) emulsion was prepared from toluene diisocyanate (TDI), polypropylene glycol (PPG) and
dimethylol propionic acid (DMPA) following a self-emulsification process. The modified poly(vinyl chloride) (PVC) emulsion
resin was obtained by in situ emulsion copolymerization using the PU as seeds in an autoclave. The effects of PU molecular
weight on the mechanical properties and thermal stability of the PU/PVC materials were investigated. The composite latex particles
and composite materials were determined and characterized using a laser particle size analyzer, transmission electron microscopy
or scanning electron microscopy. The study results showed that the PU/PVC hybrid emulsion particles possess a core/shell structure.
When the general mechanical properties of the composite materials increase, the thermal stabilities decrease a little. The
tough fractures on the surface of the PU/PVC composite sample following impact are quite obvious.
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Translated from Journal of Hebei Normal University (Natural Science Edition), 2007, 31(2): 228–232 [译自: 河北师范大学学报(自然科学版)] 相似文献
9.
Jie Gong Yang Liu Lili Wang Jinghai Yang Zhanguo Zong 《Frontiers of Chemistry in China》2008,3(2):157-160
Hexagonal close-packed Ni nanoparticles were synthesized using a heat-treating technique with the precursors prepared by the
sol-gel method. The synthesis condition, structure, and morphology of the samples were characterized and analysed by thermogravimetric
analysis (TG), differential thermal analysis (DTA), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Results
indicate that the hexagonal close packed Ni nanoparticles were synthesized at a heat-treating temperature of 300°C. The cell
constants are calculated at a = 0.2652 nm and c = 0.4334 nm. The average grain size of the hexagonal close-packed Ni particles evaluated by Scherrer equation is about 12
nm. The phase transformation from a hexagonal close-packed Ni to a face-centered cubic Ni structure occurred when the heat-treating
temperature was increased.
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Translated from Chemical Journal of Chinese Universities, 2007, 28(7): 1232–1234 [译自: 高等学校化学学报] 相似文献
10.
Kinetics of thermal decomposition of CeO2 nanocrystalline precursor prepared by precipitation method
Xiaolan Song Xi He Haiping Yang Dayu Xu Nan Jiang Guanzhou Qiu 《Frontiers of Chemistry in China》2008,3(2):182-185
The thermal decomposition of CeO2 nanocrystalline precursor prepared by chemical precipitation method was investigated using thermo-gravimetric/differential
scanning calorimetry (TG/DSC) and X-ray powder diffraction (XRD). In particular, the differential thermal analysis curves
for the decomposition of CeO2 nanocrystalline precursor were measured at different heating rates in air by a thermal analyzer (NETZSCH STA 449C, Germany).
The kinetic parameters of the thermal decomposition of CeO2 nanocrystalline precursor were calculated using the Kissinger method and the Coats-Redfern method. Results show that the
apparent active energy E of the reaction is 105.51 kJ/mol, the frequency factor lnA is 3.602 and the reaction order n is 2. This thermal decomposition process can be described by the anti-Jander equation and a three-dimensional diffusion mechanism.
Tanslated from Journal of Central South University (Science and Technology), 2007, 38(3): 428–432 [译自: 中南大学学报(自然科学版] 相似文献
11.
A novel compound of butyl crystal violet lactone (BCVL) has been prepared by oxidizing leuco butyl crystal violet lactone
(LBCVL), which was obtained by the mixture of N,N-dibutylaniline, p-(dibutylamino) benzaldehyde and methyl-m-(dibutylamino) benzoate. The structure of BCVL was characterized by 1H-nuclear magnetic resonance (NMR), infrared (IR), and mass spectrometry (MS). The color of BCVL can change reversibly in
some acid or alkali solvents. The result of the dissolution experiment showed that solubility of BCVL in organic solvent was
improved compared with crystal violet lactone (CVL).
Translated from Journal of Fudan University (Natural Science), 2006, 45(3): 375–379 [译自: 复旦学报(自然科学版)] 相似文献
12.
A novel calix[4]arene-based fluorescent chemosensor bearing a 2-aminopyridine moiety and a naphthalenic fluorophore was synthesized
The chemical structure of the product was elucidated by FT-IR, MS-FAB, NMR and elemental analyses. Then, the properties and
identification mechanism of the synthesized chemosensor were investigated. The results show that the chemosensor exhibits
selective fluorescent quenching in the presence of aromatic organic acid in acetonitrile solution, and that the binding ability
of the chemosensor with organic acid is in the order of p-cyanic-benzyl acid > p-chloric-benzyl acid > p-methoxyl-benzyl acid > benzyl acid.
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Translated from Journal of South China University of Technology (Natural Science Edition), 2007, 35(4): 20–24 [译自: 华南理工大学学报(自然科学版)] 相似文献
13.
Sr2CeO4/Ln3+ (Ln = Er, Ho, Tm) phosphors were synthesized with the microwave radiation method for the first time. The luminescent properties
of the samples were investigated and the up-conversion luminescence of Er3+, Ho3+ and Tm3+ doped Sr2CeO4 phosphors was observed. The spectra indicate that the energy transfer takes place from the triplet excited state of MLCT
(metal-to-ligand charge transfer) state for Sr2CeO4 (sensitizer) to the rare earth ions (activator).
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Translated from Journal of Hebei Normal University (Natural Science Edition), 2007, 31(2): 212–216 [译自: 河北师范大学学报 (自然科学版)] 相似文献
14.
Yingpin Li Xiaoquan Zhou Huijing Zhou Zhurui Shen Tiehong Chen 《Frontiers of Chemistry in China》2008,3(2):128-132
Manganese dioxides with various morphologies were prepared using a common hydrothermalmethod without any templates or additives.
The evolution of the morphology was accompanied by the gradual conversion of the polymorphic forms from γ-type to β-type. Meanwhile, MnO2 microspheres, urchin-like nanostructures and nanowires were successfully synthesized. The products were characterized by
X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscope. The
evolution process can be explained by the Ostwald Ripening mechanism.
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Translated from Chinese Journal of Chinese Universities 28(7): 1223–1226 [译自: 高等学校化学学报] 相似文献
15.
Yue Situ Jianfeng Hu Hong Huang Heqing Fu Hanwei Zeng Huanqin Chen 《Frontiers of Chemistry in China》2008,3(2):235-241
A novel epoxidized soybean oil (ESO) internally toughened phenolic resin(ESO-IT-PR) with both good toughness and excellent
thermal stability was prepared as the matrix resin of copper clad laminate (CCL). FTIR was adopted to investigate the molecular
structure of modified phenolic resins and SEM was used to observe the micro morphology of their impacted intersections. The
properties of CCLs prepared with these modified phenolic resins were studied to determine the optimal process and investigate
the toughening mechanism. The main modifying mechanism is the etherification reaction between phenol hydroxyl and ESO catalyzed
by triethanolamine and the chain extension polymerization between ESO and multi-amine gives the long-chain ESO epoxy grafting
on the phenolic resin prepolymer. when the ESO content is 30% and the curing agent content is 7%, the ESO toughened phenolic
resin possesses optimal performance. The flexible ESO epoxy shows significant toughening effect and it crosslinks with the
phenolic resin to form an internally toughened network, which is the key factor for improving the solderleaching resistance
of CCL prepared with this modified phenolic resin.
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Translated from Journal of South China University of Technology (Natural Science Edition), 2007, 35(7): 99–104 [译自: 华南理工大学学报(自然科学版)] 相似文献
16.
Jijun Tang Jianwei Xie Lei Guo Yan Yan Ningsheng Shao 《Frontiers of Chemistry in China》2007,2(4):431-435
Aptamers which specifically recognize targets are selected from random oligonucleotide library using systematic evolution
of ligands by exponential enrichment (SELEX). In this paper, capillary electrophoresis (CE) as a separation approach has been
introduced to SELEX procedure. The high efficiency of CE gives rise to greatly shorten the selection procedure. The results
from enzyme-linked assay and dot blot experiment show that an enrichment pool has been obtained after four rounds selection,
which can specifically recognize ricin.
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Translated from Chemical Journal of Chinese Universities, 2006, 27(10): 1,840–1,843 [译自: 高等学校化学学报] 相似文献
17.
The synthesis of the first two arylenealkyne conjugated macrocycles containing a long alkylene bridge via Glaser coupling of template-directed tetraacetylenes was reported. Tetraacetylene intermediates with complex structures were
constructed rapidly via quadruple Hagihara coupling of monoprotected bisacetylenes to appropriate tetraiodides and subsequent desilylation. The characterization
of such compounds was carried out by NMR, GPC and UV-Vis spectra. Unfortunately, the two compounds were not liquid crystals
and had no biaxial nematic mesophase character as expected.
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Translated from Chemical Journal of Chinese Universities, 2007, 28(1): 65–70 [译自: 高等学校化学学报] 相似文献
18.
The hydrophobic formation cationic starch (PSOAMDA) was prepared from starch (St), octadecyl acrylate (OA), acrylamide (AM)
and dimethyl diallyl ammonium chloride (DMDAAC) by means of inverse suspension polymerization with redox initiator. Water
with algae from Dianchi Lake was tested with PSOAMDA. Results show that when the molar ratio of St: AM: DMDAAC: OA is 4:8:1.5:0.6
and the reaction temperature is 40°C with a reaction time of 3 h, the monomer conversion yield, graft percentage and cationic
degree is 92.4%, 63.8% and 7.3%, respectively, and M
η = 3.26×106 g/vmol. It had been found from the flocculation of disposed water with algae from Dianchi Lake that the transparency and
COD elimination reach to 93.5% and 70.3%, respectively, with 15 mg/L PSOAMDA and at pH 6, vs. 91.3% and 69.2% obtained with
the commercial cationic polyacrylamide (PAM-C). When PSOAMDA dosage is 10–25 mg/L and the pH of aqueous solution is 6–10,
the flocculation performance is well capable of dealing with the water with algae from Dianchi Lake.
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Translated from Journal of Yunnan University (Natural Sciences Edition), 2007, 29(2): 177–182 [译自: 云南大学学报(自然科学版)] 相似文献
19.
Solvents have an important effect on the epoxidation of propylene catalyzed by TS-1. The experimental results show that, in
different solvents, the catalytic activity of epoxidation is in the following order: methanol > 2-propanol > 2-butanol > acetonitrile
> acetone > tetrahydrofuran. Based on the reaction mechanism, the effects of solvents on the epoxidation were studied from
eight aspects, which included the electronic effect, the steric effect, the polarity of solvent, the effect of solvent on
sorption and diffusion of reactant, the oxidation of alcohol, the etherification of PO, the deactivation of TS-1 and the solubility
of propylene in the solvents. The electronic effect, steric effect and the polarity of solvent were considered to be the main
aspects. This work may provide theoretical guidance for choosing solvents for these kinds of reactions and also may serve
as basis for further industrialization.
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Translated from Journal of Tsinghua University (Science and Technology), 2007, 47(9): 116–120 [译自: 清华大学学报(自然科学版] 相似文献
20.
Guangjun Xu Wen Gu Xiaofang Ma Li Feng Shiping Yan Daizheng Liao Peng Cheng 《Frontiers of Chemistry in China》2008,3(2):138-142
The interaction between CT-DNA and a ternary copper (II) complex, [Cu(phendio)(L-Phe)(H2O)](ClO4)·H2O (CuPP, phendio = 1,10-phenanthroline-5,6-dione, L-Phe = L-phenylalanine), has been conducted by electronic spectra, fluorescence
spectroscopy and cyclic voltammetry. It has been found that the max. absorption peak from the electronic spectra is red shifted
and the intensity is weakened and that the values of peak current from cyclic voltammetry are decreased significantly in the
presence of DNA compared with that in the absence of DNA. At the same time, the complex can quench the emission intensity
of EB-DNA system. The existence of the intercalation mode between the complex and DNA was proven. By submarine gel electrophoresis,
we found that the copper(II) complex can cleave circular plasmid pBR322 DNA into nicked and linear forms in the presence of
ascorbic acid and H2O2.
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Translated from Acta Scientiarum Naturalium Universitatis Nankaiensis, 2007, 40(1): 32–36 [译自: 南开大学学报(自然科学版)] 相似文献