Stable isotopes and chloride ion of precipitation are ideal environmental tracers to explain and reveal the formation and evolution mechanisms of water bodies. It is crucial to investigate the stable isotopes and chlo...Stable isotopes and chloride ion of precipitation are ideal environmental tracers to explain and reveal the formation and evolution mechanisms of water bodies. It is crucial to investigate the stable isotopes and chloride in precipitation events in the northeastern part of the Tibetan Plateau(NETP) due to the limitation of available data. This study sampled each event of precipitation during the period from July 2018 to June 2019 and the monthly dustfall in the NETP to investigate the temporal changes of stable isotopes and chloride in precipitation, and to reveal the moisture source of precipitation over the NETP using a back trajectory model. Results showed that the δ^(2)H values of precipitation ranged from-183.51‰ to 17.75‰, and the δ^(18)O values ranged from-25.18‰ to 0.48‰. The slope of the Local Meteoric Water Line was slightly lower than 8 due to the effect of belowcloud secondary evaporation on the precipitation process. Most d-excess values were higher than 10‰ because moisture recycled from the continent and Qinghai Lake surface mixed with precipitation. The chloride in precipitation accounted for 86.5% of the annual total deposition mass of chloride(1329.64 mg/m2), indicating that precipitation was the main source of chloride in the NETP. The temperature and amount effects of stable isotope in the precipitation were obvious in the NETP. The precipitation was predominantly derived from the Westerly Circulation from September through May and the East Asian Monsoon from June to August, with precipitation amounts of 246.5 mm and 178.0 mm, respectively, indicating that the precipitation over the NETP brought by the Westerly Circulation was more than that brought by the East Asian Monsoon. The air mass over the NETP transited in late May and early September, and a slight change in transition period would mainly be related to the intensity of the East Asian Monsoon, which is strongly influenced by El Ni?o-Southern Oscillation. These results provide not only baseline data for hydrological and climatological studies of the NETP but also valuable insights into the hydrological process in the inland arid area of Asia.展开更多
Two thiouronium iodide salts,（E）-2-methyl-1,3-diphenylisothiouronium iodide（1） and 1,3-dibenzyl-2-methylisothiouronium iodide（2）,were synthesized and characterized by single-crystal X-ray diffraction,1H NMR,IR,U...Two thiouronium iodide salts,（E）-2-methyl-1,3-diphenylisothiouronium iodide（1） and 1,3-dibenzyl-2-methylisothiouronium iodide（2）,were synthesized and characterized by single-crystal X-ray diffraction,1H NMR,IR,UV-vis and luminescence spectra.Single-crystal X-ray diffraction reveals that compound 1 crystallizes in monoclinic system,P21/n space group with a = 11.273（2）,b = 10.318（2）,c = 12.962（3） A,β = 99.03（3）°,V = 1489.0（5） A^3 and Z = 4;compound 2 crystallizes in monoclinic system,C2/c space group with a = 11.706（2）,b = 14.119（3）,c = 20.930（4） A,β = 103.84（3）°,V = 3358.8（12） A^3 and Z = 8.The thiouroniums of both compounds are Y-shaped planar structures to form a cross-conjugated system.The averaged bond lengths of C-N and C-S indicate the presence of ＂Y＂ aromaticity.The researches on UV-vis and luminescence spectra of compounds 1 and 2 indicate that they can form inclusion complex with β-CD in the aqueous solution.展开更多
A new mononuclear tin（Ⅳ） complex [Sn（edt）2L]·CH2Cl2 （edt = ethane-1,2-dithiolate, L = di-2-pyridyl-ketone p-phenyldiamine） was obtained by a one-pot reaction which involves in situ formation of a new Schif...A new mononuclear tin（Ⅳ） complex [Sn（edt）2L]·CH2Cl2 （edt = ethane-1,2-dithiolate, L = di-2-pyridyl-ketone p-phenyldiamine） was obtained by a one-pot reaction which involves in situ formation of a new Schiff-base ligand L. The title compound （C22H24C12N484Sn） crystallizes in monoclinic, space group P211n with a = 13.438（1）, b = 12.2657（10）, c = 17.1477（13） k,, β = 99.323（ 1 ）°, V = 2789.1 （4） A, Z = 4, Mr = 662.28, Dc= 1.577g/cm^3, F（000） = 1328,μ= 1.426 mm^-1, the final R = 0.0450 and wR = 0.1077 for 3868 observed reflections （1 〉 2σ））. In the title compound, Sn^4＋ ion is six-coordinated with four sulfur atoms of two edt ligands and two nitrogen atoms of the ligand di-2-pyridyl-ketone p-phenyldiamine to form a highly distorted octahedron.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.41877157, 41730854)the State Key Laboratory of Loess and Quaternary Geology (SKLLQG1904)+2 种基金the Science and Technology Support Plan for Youth Innovation of Colleges and Universities of Shandong (2019KJH009)the Natural Science Foundation of Shandong Province (ZR2019MD040)the State Key Laboratory of Earth Surface Processes and Resource Ecology (2017-KF-15)。
文摘Stable isotopes and chloride ion of precipitation are ideal environmental tracers to explain and reveal the formation and evolution mechanisms of water bodies. It is crucial to investigate the stable isotopes and chloride in precipitation events in the northeastern part of the Tibetan Plateau(NETP) due to the limitation of available data. This study sampled each event of precipitation during the period from July 2018 to June 2019 and the monthly dustfall in the NETP to investigate the temporal changes of stable isotopes and chloride in precipitation, and to reveal the moisture source of precipitation over the NETP using a back trajectory model. Results showed that the δ^(2)H values of precipitation ranged from-183.51‰ to 17.75‰, and the δ^(18)O values ranged from-25.18‰ to 0.48‰. The slope of the Local Meteoric Water Line was slightly lower than 8 due to the effect of belowcloud secondary evaporation on the precipitation process. Most d-excess values were higher than 10‰ because moisture recycled from the continent and Qinghai Lake surface mixed with precipitation. The chloride in precipitation accounted for 86.5% of the annual total deposition mass of chloride(1329.64 mg/m2), indicating that precipitation was the main source of chloride in the NETP. The temperature and amount effects of stable isotope in the precipitation were obvious in the NETP. The precipitation was predominantly derived from the Westerly Circulation from September through May and the East Asian Monsoon from June to August, with precipitation amounts of 246.5 mm and 178.0 mm, respectively, indicating that the precipitation over the NETP brought by the Westerly Circulation was more than that brought by the East Asian Monsoon. The air mass over the NETP transited in late May and early September, and a slight change in transition period would mainly be related to the intensity of the East Asian Monsoon, which is strongly influenced by El Ni?o-Southern Oscillation. These results provide not only baseline data for hydrological and climatological studies of the NETP but also valuable insights into the hydrological process in the inland arid area of Asia.
基金the financial support of the National Natural Science Foundation of China(No.21101062,21271068,21203059)Educational Commission of Hubei Province(No.Q21021402)+1 种基金Chutian Scholar Fund of Hubei Province(No.4032401)National Training Programs of Innovation and Entrepreneurship for Undergraduates(No.201210500012)
文摘Two thiouronium iodide salts,（E）-2-methyl-1,3-diphenylisothiouronium iodide（1） and 1,3-dibenzyl-2-methylisothiouronium iodide（2）,were synthesized and characterized by single-crystal X-ray diffraction,1H NMR,IR,UV-vis and luminescence spectra.Single-crystal X-ray diffraction reveals that compound 1 crystallizes in monoclinic system,P21/n space group with a = 11.273（2）,b = 10.318（2）,c = 12.962（3） A,β = 99.03（3）°,V = 1489.0（5） A^3 and Z = 4;compound 2 crystallizes in monoclinic system,C2/c space group with a = 11.706（2）,b = 14.119（3）,c = 20.930（4） A,β = 103.84（3）°,V = 3358.8（12） A^3 and Z = 8.The thiouroniums of both compounds are Y-shaped planar structures to form a cross-conjugated system.The averaged bond lengths of C-N and C-S indicate the presence of ＂Y＂ aromaticity.The researches on UV-vis and luminescence spectra of compounds 1 and 2 indicate that they can form inclusion complex with β-CD in the aqueous solution.
基金supported by the State Key Laboratory of Structural Chemistry,the NNSFC(20273073,20333070,90206040)NSF of Fujian Province(2004J041,2003J042,2004HZ01-1)
文摘A new mononuclear tin（Ⅳ） complex [Sn（edt）2L]·CH2Cl2 （edt = ethane-1,2-dithiolate, L = di-2-pyridyl-ketone p-phenyldiamine） was obtained by a one-pot reaction which involves in situ formation of a new Schiff-base ligand L. The title compound （C22H24C12N484Sn） crystallizes in monoclinic, space group P211n with a = 13.438（1）, b = 12.2657（10）, c = 17.1477（13） k,, β = 99.323（ 1 ）°, V = 2789.1 （4） A, Z = 4, Mr = 662.28, Dc= 1.577g/cm^3, F（000） = 1328,μ= 1.426 mm^-1, the final R = 0.0450 and wR = 0.1077 for 3868 observed reflections （1 〉 2σ））. In the title compound, Sn^4＋ ion is six-coordinated with four sulfur atoms of two edt ligands and two nitrogen atoms of the ligand di-2-pyridyl-ketone p-phenyldiamine to form a highly distorted octahedron.
