| 1. |
- Shi, F., et al.
(författare)
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Synthesis and properties of a new donor model compound for PSII
- 2004
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Ingår i: Gaodeng xuéxiào huàxué xuébào. - 0251-0790. ; 25:9, s. 1666-1672
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Tidskriftsartikel (refereegranskat)abstract
- As a model compound for redox components on the donor side of photosystem II (PS II) in green plants, a supramolecular complex 2 was synthesized and characterized. In this complex, two {[(2-hydroxy-3-(morpholin-4-ylmethyl)-5-tert-butyl-benzyl)(pyridyl-2-methyl)amino]methyl} arms are linked to the ortho-positions of a phenol which is expected covalently to be linked to Ru(II) tris-bipyridine through an amide bond. The arms on the substituted-phenol can coordinate two Mn(III) ions. The structure of complex 2 was confirmed by electrospray ionization mass spectrometry (ESI-MS) and 2D-NMR (gCOSY, HSQC and HMBC). Its photochemical and electrochemical properties were studied. The results showed that the MLCT band of the compound was red-shifted compared to that of [Ru(byp)(3)](2+) and the luminescence quantum yield was enhanced. In addition, the oxidation potential of ruthenium was higher than the phenol(+)/phenol and Mn(III, IV)/Mn(III) which was consisted with the electron transfer sequence of the donor side of PS II in nature. All these showed that this compound was a good model to mimic the donor side of PS II.
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| 2. |
- Shi, F., et al.
(författare)
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Synthesis and spectral properties of a new ruthenium(II) tris-bipyridine with four ester groups and substituted phenol
- 2004
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Ingår i: Huaxue xuebao. - 0567-7351. ; 62:7, s. 713-719
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Tidskriftsartikel (refereegranskat)abstract
- A new ruthenium(II) complex (1) with four ester groups have been designed and synthesized, in which a phenol substituted by {[(2-hydroxy-3-(morpholin-4-ylmethyl)-5-tent-butylbenzyl) (pyridyl-2-methyl) amino]methyl} groups was covalently linked to ruthenium (II) tris-bipyridine. The structure of complex 1 was characterized by electrospray ionization mass spectrometer (ESI-MS) and 1D-NMR, 2D-NMR (gCOSY, HSQC and HMBC) spectra. The electrochemical and spectral properties were also studied. Introduction of the four carboxyl acid groups and the donor ligand tuned the spectra and the redox properties of compound 1. The MLCT transition was turned from 451 to 474 nm and the complex had long lifetime of the (MLCT)-M-3 state emission. Moreover, the oxidation potential of Ru3+/Ru2 + of compound 1 was similar to 360 mV higher than that of [Ru(bpy)(3)](2+) which would enhance the driving-force of electron transfer. These results showed that the compound 1 had proper redox potentials and was suitable for being used as photosensitizer of solar cell.
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| 3. |
- Sun, S. G., et al.
(författare)
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Electrospray ionization mass spectrometry of rhenium(I) bipyridyl complexes
- 2003
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Ingår i: Youji huaxue. - 0253-2786. ; 23:10, s. 1135-1138
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Tidskriftsartikel (refereegranskat)abstract
- The electrospray ionization mass spectrometry (ESI-MS) of a series of rhenium(I) bipyridyl complexes [(4,4'-(COOEt)(2)-bPY)Re(CO)(3)RPF6], where bpy is 2,2'-bipyridine and R is pyridine, 4-methylpyridine, 4-hydroxypyridine, 4-aminopyridine or 10-(4-picolyl)phenothiazine (py-PTZ) was studied. The dissociation of the ligands (R) forms the fragment of [(4, 4'-( COOEt)(2)-bpy) Re (CO)3](+) at different voltages of in-source collision induced dissociation (CID). The dissociation tendency is in an order: pyridine > 4-methylpyridine > 4-hydroxypyridine > 4-aminopyridine > py-PTZ. It might be used to deduce the stability of these complexes when they are used as photosensitizers in solar cells.
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| 4. |
- Sun, S. G., et al.
(författare)
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Studies on a series of rhenium(I) bipyridyl photosensitive dyes
- 2004
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Ingår i: Youji huaxue. - 0253-2786. ; 24:8, s. 953-956
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Tidskriftsartikel (refereegranskat)abstract
- A series of rhemium(I) 2,2'-bipyridyl complexes [fac-(4,4'-di-COOEt-bpy)Re(CO)(3)(Xpy)PF6] (bpy = 2, 2'-bipyridine; py = pyridine; X = 3-methyl, 3-hydroxy, 3-amino, H) were synthesized. Their electrochemical properties, ground state electronic spectra and emission spectra were studied in acetonitrile. As the X group became more electron donating from H to 3-methyl, 3-hydroxy or 3-amino, the Re(II/I) oxidation potentials declined, the MLCT absorption maximum of the complex was changed little, the emission maximum blue-shifted, and the emission intensity and the fluorescence lifetime were decreased.
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| 5. |
- Sun, S. G., et al.
(författare)
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Synthesis of a series of rhenium(I) bipyridyl complexes as photosensitive dyes
- 2004
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Ingår i: Gaodeng xuéxiào huàxué xuébào. - 0251-0790. ; 25:5, s. 820-822
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Tidskriftsartikel (refereegranskat)abstract
- In order to study the effects of the substituted groups on the properties of the complexes, a series of rhenium ( I ) 2, 2'-bipyridyl complexes [fac- (4, 4'-di-COOEt-bpy) Re (CO)(3) (X-pyridine) PF6], where bpy is 2,2'-bipyridine and X is 4-methyl, 3-hydroxy, 4-hydroxy, 4-amino, or H, were synthesized with a yield more than 90%, and characterized by H-1 NMR, C-13 NMR, 2D-NMR (H-1-H-1 COSY, HMBC, HSQC), ESI-MS and HRMS. The delta(H) values on the X-pyridine ring were shifted to up-field in H-1 NMR and the MLCT absorbance maxima were red-shifted as the X groups became more electron-donating from H to 4-methyl, 4-hydroxy or 4-amino. The ESI-MS and FIRMS showed the mono-charged peaks and their isotopic peaks of the complexes. The absorption maximum of id(X=4-amino) is 20 nm longer than that of 1e(X=H). It might be used to broaden the absorption range of solar cells.
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| 6. |
- Sun, S. G., et al.
(författare)
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Synthesis of rhenium(I) bipyridyl and ruthenium(II) tris-bipyridyl photosensitive dyes used for solar cells
- 2004
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Ingår i: Gaodeng xuéxiào huàxué xuébào. - 0251-0790. ; 25:1, s. 67-70
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Tidskriftsartikel (refereegranskat)abstract
- There has been a growing effort to convert solar energy into electricity in recent years. In order to get a stable solar cell system and acquire a high incident photon-to-current conversion efficiency(IPCE), two novel rhenium(I) bipyridyl and ruthenium(II) tris-bipyridyl photosensitive dyes were synthesized, the ethoxycarbonyl group in the dyes could be employed for covalently linking to the surface of the nanostructured TiO2. Their structures, photophysical and electrochemical properties were studied. The UV-Vis absorption maxima were 382 and 476 nm; emission maxima were 622 and 672 nm, respectively. The Re(I/II) oxidation potential is significantly positive than that of Ru(II/III) which provides a larger driving force for electron transfer. The results show that they both have proper redox potentials, enough stability and are suitable for being used as photosensitizers of solar cells.
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| 7. |
- Guo, X. W., et al.
(författare)
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Methylation of 4-methylbiphenyl with methanol over metal oxide-modified HZSM-5 zeolite catalysts
- 2003
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Ingår i: Cuihuà xuébào. - 0253-9837 .- 1872-2067. ; 24:5, s. 333-337
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Tidskriftsartikel (refereegranskat)abstract
- A series of HZSM-5 zeolite catalysts modifed with metal oxides (MgO, CaO, SrO, BaO, ZnO, La2O3 and CeO2) were prepared by impregnation method and characterized by XRD, TPD and N-2-adsorption. Methylation of 4-methylbiphenyl (4-MBP) with methanol to 4,4'-dimethylbiphenyl (4,4'-DMBP) was carried out over the prepared catalysts under fixed-bed down-flow conditions. The results showed that the MgO-modified HZSM-5 can significantly improve the selectivity for target product 4,4'-DMBP (up to 80 % vs only 13 % over the parent HZSM-5). The effects of metal oxides on 4,4'-DMBP selectivity are arranged in the following order: MgO>SrOapproximate toZnOapproximate toCaOapproximate toLa(2)O(3)>BaO>CeO2. The effects of MgO contents, precursor-salt types, and loading methods were further investigated, and the results revealed that during 4-MBP conversion, proper MgO loading (5.6 %) can be more effective, and the ion-exchange methed is much better than the impregnation method. However, it is difficult to get higher metal oxide loading by using the ion-exchange method. The high selectivity over HZSM-5 modified with MgO largely results from the depression of 4,4-DMBP second reactions such as isomerization, dealkylation and alkylation, as demonstrated by the reaction of 4,4'-DMBP as reactant over MgO/ZSM-5 catalyst and HZSM-5 zeolite.
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| 8. |
- Guo, Yanfei, 1984, et al.
(författare)
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Frailty trajectories in people aged 50 years and above in China
- 2022
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Ingår i: Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi. - 0254-6450. ; 43:11, s. 1711-1716
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Tidskriftsartikel (refereegranskat)abstract
- 目的： 识别中国≥50岁人群的衰弱轨迹，并探索相关影响因素。 方法： 采用WHO“全球老龄化与成人健康研究”（SAGE）中国项目第一至第三轮纵向数据，由32种变量计算衰弱指数得分，并在此基础上在组基轨迹模型中采用删失正态模型确定随时间变化的衰弱轨迹模式，采用多项式logistic回归模型研究社会经济地位和行为影响因素对衰弱轨迹的影响。 结果： 共纳入4 303名≥50岁且拥有3轮完整数据的调查对象进入分析，本研究识别出3条衰弱轨迹：低水平稳定轨迹（LT）、中度增加轨迹（MT）和高度增加轨迹（HT），分别占所有调查对象的75.9%，19.1%和5.0%。多项式logistic回归分析的结果显示，与LT组相比，HT组更倾向是女性（OR=1.88，95%CI：1.22~2.92）和农村居民（OR=1.87，95%CI：1.29~2.70）。在家庭人均财富方面，OR值有一个明显的梯度，较低的家庭财富更有可能归为HT组。 结论： 本研究识别出了3种我国≥50岁人群衰弱轨迹的进展模式，并强调了干预措施应尽可能地以那些衰弱进展快速的脆弱人群为目标。. Objective: To identify distinct frailty trajectories in a cohort of nationwide community adults aged 50 years and above, and explore the relationship between frailty trajectories and their socioeconomic characteristics and behavioral factors at baseline survey. Methods: Data were from the three waves of "Global Ageing and Adult Health Research" (SAGE) by World Health Organization in China. The frailty index is generated from 32 items. Group-based trajectory modeling using a censored normal model was conducted to identify the patterns in frailty progression over time. Multinomial logistic regression model was used to examine the effect of socioeconomic status and behavioral factors on the frailty trajectories. Results: A total of 4 303 adults aged 50 years and above with complete data from all three rounds of project were included in the final analysis. Three frailty trajectories were identified: low and stable trajectory (LT) (56.8%), moderately increased trajectory (MT) (34.4%) and highly increased trajectory (HT) (8.8%). The results of the multinomial logistic regression analysis showed that the HT group was more likely to be women (OR=1.88, 95%CI:1.22-2.92) and rural residents (OR=1.87, 95%CI:1.29-2.70) compared with the LT group. In terms of household wealth per capita, there was a clear gradient in ORs, the people with lower household wealth were more likely to be classified in the HT group. Conclusion: This study identified three patterns of progression of frailty trajectories in population aged 50 years and above in China and highlighted that interventions should target those vulnerable populations with rapid progression of frailty.
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| 9. |
- He, C. J., et al.
(författare)
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Advance in chemical mimic of Fe-only hydrogenase
- 2004
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Ingår i: Huaxue jinzhan. - 1005-281X. ; 16:2, s. 250-255
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Tidskriftsartikel (refereegranskat)abstract
- Hydrogenases are one of the important enzymes in many microorganisms, which can catalyze the reversible oxidation of hydrogen. They are classified into three categories according to their active metal centers, that is, Fe-only, [Ni-Fe] and metal free H-2 ases. This review introduces primarily the recent advances in structural investigation and chemical mimic of Fe-only H-2 ases.
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| 10. |
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