CHEMICAL PAPERS
·
2018
·Vol. 72
·期 9
·2203-2214
·
IF 0.963
Sun Qian,Song Xueying,Gao Li,Chen Wei,Li Yamin,Mao Liqun,Yang Jing-He
The series of graphene materials and N-doped graphene materials were successfully synthesized and improved by high-temperature treatment with trace iron oxide. XRD, Raman, FT-IR, TEM and XPS were employed for these catalysts. The catalytic performance of these catalysts was investigated in the selective oxidation of ethylbenzene with tert -butyl hydroperoxide as oxidant. The impacts of temperature, mass of catalysts, reaction time and oxidants on the selective oxidation of ethylbenzene were also investigated. The N-doped graphene materials exhibit greatly remarkable catalytic performance than others. The conversion of ethylbenzene is more than 90% and the selectivity of acetophenone is more than 95% at 353 K. Graphene can be used as catalyst owing to its unique structures and chemical properties. The characterization tests show that the doping of N atoms can create more defects and more active sites in the N-doped graphene materials which could greatly improve the catalytic performance. Furthermore, such cost-effective graphene-based catalysts possess good stability and could be reused at least five times without remarkable loss of the catalytic activity.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2015
·Vol. 22
·期 24
·19596-19606
·
IF 2.828
Ran Xiaofei,Yue Hong,Fu Xiaoli,Kang Yuanhao,Xu Sha,Yang Yanjun,Xu Jinzhu,Shi Junqiong,Wu Zhongxing
The response and detoxification mechanisms of three freshwater phytoplankton species (the cyanobacterium Aphanizomenon flos-aquae , the green alga Pediastrum simplex , and the diatom Synedra acus ) to cadmium (Cd) were investigated. The cell growth of each species was measured over 10 days, and chlorophyll a fluorescence, Cd bioaccumulation (including surface-adsorbed and intracellular Cd), and phytochelatin (PC) synthesis were determined after 96-h exposures. The growth of the three phytoplankton species was significantly inhibited when Cd concentrations were ≥5 mg L −1 . Compared with P. simplex , greater growth inhibition in S. acus and A. flos-aquae occurred. The changes in chlorophyll fluorescence parameters including the maximal quantum yield of PSII (Fv/Fm) and relative variable fluorescence of the J point (Vj) demonstrated that the increase in Cd concentration damaged PSII in all three species. After 96-h exposures, the accumulation of surface-adsorbed Cd and intracellular Cd increased significantly in all three species, with the increase of Cd concentrations in the media; total cadmium accumulation was 245, 658, and 1670 times greater than that of the control in A. flos-aquae , P. simplex , and S. acus , respectively, after exposure to 10 mg L −1 . Total thiols exhibited a similar trend to that of Cd accumulation. PC 3 was found in A. flos-aquae and P. simplex in all Cd treatments. Glutathione (GSH) and PC 2 were also produced in response to exposure to high concentrations of Cd. PC 4 was only discovered at exposure concentrations of 10 mg L −1 Cd and only in S. acus . The intracellular Cd/PCs ratio increased in all three phytoplankton with an increase in Cd concentrations, and a linear relationship between the ratio and the growth inhibition rates was observed with P. simplex and S. acus . Our results have demonstrated that metal detoxification mechanisms were dependent on the species. This study suggested that the variance of metal detoxification strategies, such as cadmium accumulation and PCs, might be an explanation why algal species have different sensitivity to Cd at various levels.
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高影响因子
GLYCOCONJUGATE JOURNAL
·
2015
·Vol. 32
·期 8
·643-653
·
IF 2.52
Liang Qun Tao,Du Jia Yan,Fu Qing,Lin Jiang Hui,Wei Zheng
The rare N-unsubstituted glucosamine (GlcNH 3
+ ) residues in heparan sulfate (HS) have important biological and pathophysiological roles. Therefore, the ability to chemically generate a series of oligosaccharides, which have a similar structure to the naturally-occurring, GlcNH 3
+ - containing oligosaccharides from HS, would greatly contribute to investigating their natural role in HS. In this study, a hexasaccharide library that possess GlcNH 3
+ residues were prepared from the chemical modification of the fully sulfated dp6. Chemical reaction conditions were optimized to generate different pattern of GlcNH 3
+ - containing oligosaccharides, then the structure of the library was detected by high-performance liquid chromatography-ion trap/time-of-flight mass spectrometry (LC/MS-ITTOF) analysis. EIC/MS and MS 2 analysis showed different fragmentation patterns of dp6s with different GlcNH 3
+ residues. This provides a foundation for further identification and quantification of GlcNH 3
+ - oligosaccharides by mass spectrum analysis.
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高影响因子
Journal of Coatings Technology and Research
·
2013
·Vol. 10
·期 5
·621-629
·
IF 1.094
Xiong Jinsu,Jin Yunquan,Shentu Baoqing,Weng Zhixue
Poly[1,2-propylene glycol-3-(2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptoxy)]phthalate (PDFP) was prepared by the reaction of phthalic anhydride, epichlorohydrin, and 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl glycidyl ether (DFGE). The structure of PDFP was characterized with 1 H-NMR, 19 F-NMR, FTIR and the wettability of water and oil on cured PDFP coatings was investigated by contact angle meter. The results showed that the contact angle of water and diiodomethane on cured coatings increased with the increase of the fluorine content and could maximally attain 108° and 69°, respectively. At a fluorine content of 0.75%, the surface energy was 21.1 mJ/m 2 . X-ray photoelectron spectroscopic (XPS) analysis showed that the surface F/C atomic ratio was much higher than the overall F/C molar ratio, indicating that the fluoroalkyl groups in PDFP had enriched on the coating surface. It was also found that the fluorinated polyester with longer fluoroalkyl groups had the higher tendency to enrich on the coating surface.
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JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2013
·Vol. 113
·期 3
·1297-1302
·
IF 1.982
Yan X.,Wang T. B.,Pei H. R.,Wang L. P.,Lan X. Z.
Phase behavior of dodecane–tridecane ( n -C 12 H 26 –C 13 H 28 , C 12 –C 13 ) mixtures in bulk and confined in SBA-15 have been investigated using differential scanning calorimetry. Bulk C 12 –C 13 system has a complicated behavior due to special rotator phase. It has been found that phase diagram of C 12 –C 13 /SBA-15 (3.8 nm) system is a straight line, C 12 –C 13 /SBA-15 (7.8 nm) a curve, and C 12 –C 13 /SBA-15 (8.9, and 17.2 nm) a loop line. The growth of the phase diagram shows size effect on phase behavior of C 12 –C 13 mixtures. Moreover, in the range of 3.8–17.2 nm melting temperatures of pure C 12 and mixtures at mole fractions x
C13 = 0.1–0.5 have linear relation with inverse pore diameter, while C 13 and mixtures at x
C13 = 0.6–0.9 present curved lines. The confined mixtures show a similar melting behavior with pure C 12 , C 13 .
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MICROCHIMICA ACTA
·
2013
·Vol. 180
·期 5
·341-346
·
IF 3.434
Hou Fang,Deng Ting,Jiang Xinyu
We have developed a simple and efficient method for dispersive liquid-liquid microextraction of 4-nitrophenol, 2-naphthol and bisphenol A in real water samples. It is making use of solidified floating organic droplets of 1-dodecanol which has low density and a proper melting point. The type and volume of extraction solvent and dispersive solvent, the effect of salts, pH value and extraction time were optimized and resulted in enrichment factors of 84 for 4-nitrophenol, 123 for 2-naphthol, and 97 for bisphenol A. The limits of detection by HPLC are 1.50, 0.10 and 1.02 ng · mL −1 , respectively. Excellent linearity is observed in the concentration range from 10 to 800 ng · mL −1 , with coefficients of correlation ranging from 0.9988 to 0.9999. The relative standard deviations (for n = 5) are from 3.2 to 5.3 %, and relative recoveries for the three phenols in tap, river and spring water range from 85.0 to 105.0 %, 98.3 to 110.0 %, and 98.6 to 109.0 %, respectively.
Chromatograms of river water blank (b) and spiked river water (a, 500 ng ∙ mL −1 ) analyzed with DLLME-SFO-HPLC. Peak identification: (1) p-nitrophenol; (2) 2-naphthol; (3) bisphenol A. Liquid-liquid microextraction method based on solidification of floating organic droplet (DLLME-SFO) has a high enrichment factor (84, 123and 97), acceptable relative recovery (85.0 %–110.0 %), good repeatability (5.27 %, 3.54 % and 3.16 %) and a wide linear range (10–800 ng · mL −1 ) for the determination of p-nitrophenol, 2-naphthol and bisphenol A.
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Nanoscale Research Letters
·
2013
·Vol. 8
·期 1
·1-7
·
IF 2.524
Hu Hongwei,Ding Jianning,Zhang Shuai,Li Yan,Bai Li,Yuan Ningyi
Ag 2 S quantum dots were deposited on the surface of TiO 2 nanorod arrays by a two-step photodeposition. The prepared TiO 2 nanorod arrays as well as the Ag 2 S deposited electrodes were characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscope, suggesting a large coverage of Ag 2 S quantum dots on the ordered TiO 2 nanorod arrays. UV–vis absorption spectra of Ag 2 S deposited electrodes show a broad absorption range of the visible light. The quantum dot-sensitized solar cells (QDSSCs) based on these electrodes were fabricated, and the photoelectrochemical properties were examined. A high photocurrent density of 10.25 mA/cm 2 with a conversion efficiency of 0.98% at AM 1.5 solar light of 100 mW/cm 2 was obtained with an optimal photodeposition time. The performance of the QDSSC at different incident light intensities was also investigated. The results display a better performance at a lower incident light level with a conversion efficiency of 1.25% at 47 mW/cm 2 .
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JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2012
·Vol. 17
·期 4
·961-968
·
IF 2.131
Yue Lu,Zhong Haoxiang,Tang Daoping,Zhang Lingzhi
A novel porous Si/S-doped carbon composite was prepared by a magnesiothermic reaction of mesoporous SiO 2 , subsequently coating with a sulfur-containing polymer-poly(3,4-ethylene dioxythiophene), and a post-carbonization process. The as-prepared Si composite was homogeneously coated with disordered S-doped carbon with 2.6 wt.% S in the composite and retained a high surface area of 58.8 m 2 g −1 . The Si/S-doped carbon composite exhibited superior electrochemical performance and long cycle life as an anode material in lithium ion cells, showing a stable reversible capacity of 450 mAh g −1 even at a high current rate of 6,000 mA g −1 .
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APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2014
·Vol. 118
·期 3
·989-996
·
IF 1.694
Cai Bin,Zhou Yu,Zhao Minggang,Cai Hui,Ye Zhizhen,Wang Lei,Huang Jingyun
In this work, ZnO–CuO composite porous spheres with core–shell structure were successfully synthesized through a controllable simple top-down route to take advantage of the excellent features of ZnO and CuO. The crystal structure and morphology of the as-prepared products were characterized, and a possible growth mechanism was proposed. The obtained sample with a core surrounded by a porous shell has a large surface area. As CuO can well catalyze glucose in alkaline solution, together with the good electron transfer property of ZnO and the hetero-junction formed between them, non-enzymatic glucose sensors based on ZnO–CuO composite porous spheres show good performance with a wide linear range of 0.02–4.86 mM, a high sensitivity of 1,217.4 μA cm −2 mM −1 , and a low detection limit of 1.677 μM, indicating a good detection behavior of glucose.
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MICROCHIMICA ACTA
·
2014
·Vol. 182
·期 3
·737-744
·
IF 3.719
Yang Jing,Si Ling,Cui Shihai,Bi Wentao
We have developed a facile in-situ growth method for the deposition of magnetite (Fe 3 O 4 ) particles on the surface of a graphitic carbon nitride (g-C 3 N 4 ) nanosheet. The material was characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The high affinity of g-C 3 N 4 for phenolic acids in combination with the magnetism of Fe 3 O 4 provides an efficient means for magnetic solid phase extraction. The adsorption, desorption and recoveries were examined. Under optimized conditions, the method has limits of detection in the range from 17.5–42.6 ng mL −1 (at an S/N of 3), and precisions from 2.8–3.8 % (for n = 5). The method was successfully applied to the determination of protocatechuic, caffeic, and ferulic acids in Salicornia herbacea L . plant extracts. Recoveries ranged from 92.4–99.5 %.
The high affinity of g-C 3 N 4 toward the phenolic acids as well as the magnetic behavior of Fe 3 O 4 were combined in this nanocomposite material to provide an efficient and simple magnetic solid phase extraction (MSPE) approach.
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CELL BIOCHEMISTRY AND BIOPHYSICS
·
2014
·Vol. 71
·期 2
·971-976
·
IF 2.38
Zhou Yan,Gao Yuan,Chen Yingying,Zheng Rui,Zhang Wei,Tan Mingqi
The present research assessed the effects of lettuce glycoside B (LGB), a compound separated and purified from Pterocypsela
laciniata , on irradiation-induced pulmonary fibrosis and explored the mechanism involved. Animal model of irradiation exposure inducing pulmonary fibrosis was established by Co irradiator. Rats were intraperitoneally treated with LGB (100, 200 and 400 mg/kg) once per day for a month. Lung index data were analyzed. The levels of fibrosis were assessed by hydroxyproline (Hyp) of pulmonary and lung tissue sections after irradiation exposure. Alveolitis and fibrosis levels were calculated from semi-quantitative analysis of hematoxylin and eosin and Masson’s trichrome lung section staining. The serum levels of transforming growth factor β1 (TGF-β1), interleukin (IL)-6, and tumor necrosis factor-α (TNF-α) were also evaluated. Antioxidant enzymes of superoxide dismutase (SOD) were measured in serum. Moreover, we also measured serum malondialdehyde (MDA) levels, a marker of oxidative stress. Treatment with LGB significantly reduced mortality rates and lung index scores and MDA content, enhanced SOD and other antioxidant enzymes activity, and regulated serum levels of TGF-β1, IL-6, and TNF-α. These results demonstrated that LGB significantly inhibited irradiation-induced pulmonary fibrosis. Furthermore, the results suggested promising clinical effect of LGB therapies for treating irradiation-induced pulmonary fibrosis.
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COLLOID AND POLYMER SCIENCE
·
2014
·Vol. 293
·期 1
·277-288
·
IF 2.41
Cao Zhihai,Yang Liu,Chen Hangnan,Xu Chang,Qi Dongming,Zhu Shudi,Ziener Ulrich
Au/amorphous TiO 2 nanocomposite particles with high visible-light photocatalytic activity were conveniently prepared in inverse miniemulsions. The materials were synthesized through a combination of a sol–gel process and in situ reduction of HAuCl 4 by hydrazine to Au nanoparticles in the nanocomposite particles. The photocatalytic activity of the as-synthesized Au/amorphous TiO 2 nanocomposite particles is much higher than that of the Au/anatase TiO 2 and Au/rutile TiO 2 nanocomposite particles prepared by calcination. Therefore, no further heat treatments are required to achieve visible-light photocatalytic active catalysts. The loading of Au in the nanocomposite particles could be conveniently tuned by varying the HAuCl 4 loading in the dispersed phase of the inverse miniemulsions. Only a small amount of Au was required to achieve a high photocatalytic activity. The size, particle morphology, TiO 2 phase, optical property, elemental content and distribution, and pore properties of the Au/TiO 2 nanocomposite particles were systematically characterized by dynamic light scattering, transmission/scanning electron microscopy, X-ray diffraction, Raman spectroscopy, UV–vis spectroscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and N 2 sorption measurements.
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