[Objective] The rasearch aimed to grasp the spatial and temporal distribution charactedstics of extreme precipitation in Jiangsu Prov- ince. [Methodl Threshold was determined by detrended fluctuation analysis (DFA) ...[Objective] The rasearch aimed to grasp the spatial and temporal distribution charactedstics of extreme precipitation in Jiangsu Prov- ince. [Methodl Threshold was determined by detrended fluctuation analysis (DFA) based on the data of daily precipitation over Jiangsu Province from 1961 to 2010, and the oscillation pedod and mutation were detected by the method of Morlet wavelet analysis and Mann-Kendall test respec- tively. [ Result~ The annual frequency of extreme precipitation in Jiangsu Province demonstrated oscillation characteristics with 8 -10 a, and the mutation mainly happened in 2006, In addition, the oscillation period of extreme precipitation during summer was 8 -10 a, and its mutation hap- pened in 1998. The oscillation periods of extreme precipitation, however, during autumn were 2 -3 and 5 -7 a. Extreme precipitation and total rain- fall had better consistency. They both presented the characteristics of more in the south and less in the north, and big-small-value zone was concentrated. [ Conclusion] The research could provide technical support for making defense policy of the related disaster for relevant departments.展开更多
Fluorescence detecting both organic and inorganic analytes has aroused tremendous scientific interests, because fluorescence techniques have high sensitivity and are easy to operate. A new threedimensional(3D) MOF {[(...Fluorescence detecting both organic and inorganic analytes has aroused tremendous scientific interests, because fluorescence techniques have high sensitivity and are easy to operate. A new threedimensional(3D) MOF {[(CH_(3))_(2)NH_(2)][Zn_(3)(bbip)(BTDI)1.5(OH)]·DMF·MeOH·3H_(2)O}n(JXUST-13, bbip = 2,6-bis(benzimidazol-1-yl)pyridine and H_(4)BTDI = 5,5-(benzo[c][1,2,5]thiadiazole-4,7-diyl)diisophthalic acid)with new 4,4,8-connceted topology has been successfully synthesized and structurally characterized. Importantly, JXUST-13 could recognize H_(2)PO_(4)-and acetylacetone(Acac) by obvious fluorescence blue shift and slight enhancement with the detection limits of 2.70 μmol/L and 0.21 mmol/L, respectively. In addition, JXUST-13 exhibits relatively good thermal stability, chemical stabilities as well as reusability, and the analytes could be distinguished by naked eye and fluorescence test paper. Remarkably, JXUST-13 is the first dual-responsive MOF sensor based on fluorescence blue shift for the detection of H_(2)PO_(4)-and Acac with good selectivity in a handy, economic, and environmentally friendly manner.展开更多
According to the statistical shape-slope (μ-A) relationship observed for the first time by several 2D-Video-Distro-meters (2DVD) in southern China, a constrained gamma (C-G) model was proposed for the retrieval...According to the statistical shape-slope (μ-A) relationship observed for the first time by several 2D-Video-Distro-meters (2DVD) in southern China, a constrained gamma (C-G) model was proposed for the retrieval of rain drop size distributions (DSDs) from Guangzhou S-band polarimetric radar observations. Two typical precipitation processes were selected to verify the accuracy of the retrieval scheme. The p-A relationship: A = 0.0241μ^2 + 0.867μ + 2.453 was obtained based on the 2DVD observation results from at Huizhou Longmen station, which is a very representat-ive location in the area. Relying on the Guangzhou polarimetric radar measurements of radar reflectivity (ZHH) and differential reflectivity (ZDR), the gamma (F) size distribution parameters (No, μ, and A) can be retrieved by the C-G model retrieval scheme. The results show that the Guangzhou polarimetric radar retrievals of DSDs were close to the 2DVD observations at Guangzhou Maofengshan station. The rain rate, mass mean diameter, and normalized inter-cept parameter of radar retrievals were in good agreement with the 2DVD observations, and the relative errors were less than 10%. The overall accuracy of the retrieval scheme was high. The retrieval scheme has established the rela-tionship between the polarimetric radar measurements and gamma size distribution parameters. It will be helpful to in-depth research and application of the dual-polarization radar data in microphysical precipitation processes analysis, as well as convection-resolved numerical model data assimilation and prediction effect evaluation.展开更多
A novel ZnII-based metal-organic framework with the formula of{[Zn_(2)(BBIP)_(2)(NDC)_(2)]·H_(2)O}n(JXUST-5)derived from 3,5-bis(benzimidazol-1-yl)pyridine(BBIP)and 1,4-naphthalenedicarboxylic acid(H_(2)NDC)has b...A novel ZnII-based metal-organic framework with the formula of{[Zn_(2)(BBIP)_(2)(NDC)_(2)]·H_(2)O}n(JXUST-5)derived from 3,5-bis(benzimidazol-1-yl)pyridine(BBIP)and 1,4-naphthalenedicarboxylic acid(H_(2)NDC)has been synthesized.The adjacent Zn^(II)ions are linked through two BBIP ligands to form a[Zn_(2)(BBIP)_(2)]secondary building unit(SBU).The neighbouring SBUs are further connected by NDC^(2-)withμ2-η^(1):η^(1)andμ2-η^(1):η^(1):η^(1)bridging modes to form a two-dimensional(2D)framework.Topological analysis shows that JXUST-5 could be simplified as an uninodal fes topology with a point symbol of{4.8^(2)}.Furthermore,the 2D framework net could be extended through C-H···πinteraction to form the three-dimensional supramolecular structure.Luminescent experiments suggest that JXUST-5 could selectively and sensitively recognize Al^(3+)and Ga^(3+)through fluorescence enhancement effect along with a relatively large red shift.The detection limits for Al^(3+)and Ga^(3+)are 0.17 and 0.69 ppm,respectively.Interestingly,the sensing process for both Al^(3+)and Ga^(3+)could be directly observed with naked eyes under 365 nm UV lamp.Notably,JXUST-5 could be recycled at least five times as a fluorescent sensor toward Al^(3+)and Ga^(3+),which is the second example of turn-on MOF based fluorescent sensor toward Ga^(3+).展开更多
基金Supported by Natural Science Foundation of Jiangsu Province,China(BK2009412)Special Project of Science Research in Public WelfareSector(Meteorology),China(GYHY200906021)Construction Project of Advantage Discipline in University of Jiangsu,China
文摘[Objective] The rasearch aimed to grasp the spatial and temporal distribution charactedstics of extreme precipitation in Jiangsu Prov- ince. [Methodl Threshold was determined by detrended fluctuation analysis (DFA) based on the data of daily precipitation over Jiangsu Province from 1961 to 2010, and the oscillation pedod and mutation were detected by the method of Morlet wavelet analysis and Mann-Kendall test respec- tively. [ Result~ The annual frequency of extreme precipitation in Jiangsu Province demonstrated oscillation characteristics with 8 -10 a, and the mutation mainly happened in 2006, In addition, the oscillation period of extreme precipitation during summer was 8 -10 a, and its mutation hap- pened in 1998. The oscillation periods of extreme precipitation, however, during autumn were 2 -3 and 5 -7 a. Extreme precipitation and total rain- fall had better consistency. They both presented the characteristics of more in the south and less in the north, and big-small-value zone was concentrated. [ Conclusion] The research could provide technical support for making defense policy of the related disaster for relevant departments.
基金supported by the National Natural Science Foundation of China (Nos. 22061019, 21861018, 22161019 and 12174172)the NSF of Jiangxi Province (No. 20202ACBL213001)+4 种基金Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry(No. 20212BCD42018)Fujian Key Laboratory of Functional Marine Sensing Materials,Minjiang University (No. MJUKF-FMSM202010)the Youth Jinggang Scholars Program in Jiangxi Province (No.QNJG2019053)the Two Thousand Program in Jiangxi Province (No.jxsq2019201068)the Special Foundation for Postgraduate Innovation in Jiangxi Province (No. YC_(2)020-B155)。
文摘Fluorescence detecting both organic and inorganic analytes has aroused tremendous scientific interests, because fluorescence techniques have high sensitivity and are easy to operate. A new threedimensional(3D) MOF {[(CH_(3))_(2)NH_(2)][Zn_(3)(bbip)(BTDI)1.5(OH)]·DMF·MeOH·3H_(2)O}n(JXUST-13, bbip = 2,6-bis(benzimidazol-1-yl)pyridine and H_(4)BTDI = 5,5-(benzo[c][1,2,5]thiadiazole-4,7-diyl)diisophthalic acid)with new 4,4,8-connceted topology has been successfully synthesized and structurally characterized. Importantly, JXUST-13 could recognize H_(2)PO_(4)-and acetylacetone(Acac) by obvious fluorescence blue shift and slight enhancement with the detection limits of 2.70 μmol/L and 0.21 mmol/L, respectively. In addition, JXUST-13 exhibits relatively good thermal stability, chemical stabilities as well as reusability, and the analytes could be distinguished by naked eye and fluorescence test paper. Remarkably, JXUST-13 is the first dual-responsive MOF sensor based on fluorescence blue shift for the detection of H_(2)PO_(4)-and Acac with good selectivity in a handy, economic, and environmentally friendly manner.
基金Supported by the National(Key)Basic Research and Development(973)Program of China(2015CB452802)Natrional Key Research and Development Program of China(2017YFC1501701)+3 种基金National Natural Science Foundation of China(41475102,41705020,and 41705120)China Meteorological Administration Special Public Welfare Research Fund(GYHY201406013)Guangdong Province Science and Technology Project(2015B020217001)Natural Science Foundation of Guangdong Province(2016A030313141)
文摘According to the statistical shape-slope (μ-A) relationship observed for the first time by several 2D-Video-Distro-meters (2DVD) in southern China, a constrained gamma (C-G) model was proposed for the retrieval of rain drop size distributions (DSDs) from Guangzhou S-band polarimetric radar observations. Two typical precipitation processes were selected to verify the accuracy of the retrieval scheme. The p-A relationship: A = 0.0241μ^2 + 0.867μ + 2.453 was obtained based on the 2DVD observation results from at Huizhou Longmen station, which is a very representat-ive location in the area. Relying on the Guangzhou polarimetric radar measurements of radar reflectivity (ZHH) and differential reflectivity (ZDR), the gamma (F) size distribution parameters (No, μ, and A) can be retrieved by the C-G model retrieval scheme. The results show that the Guangzhou polarimetric radar retrievals of DSDs were close to the 2DVD observations at Guangzhou Maofengshan station. The rain rate, mass mean diameter, and normalized inter-cept parameter of radar retrievals were in good agreement with the 2DVD observations, and the relative errors were less than 10%. The overall accuracy of the retrieval scheme was high. The retrieval scheme has established the rela-tionship between the polarimetric radar measurements and gamma size distribution parameters. It will be helpful to in-depth research and application of the dual-polarization radar data in microphysical precipitation processes analysis, as well as convection-resolved numerical model data assimilation and prediction effect evaluation.
基金supported from the National Natural Science Foundation of China(Nos.22061019,21761012 and 21861018)the Natural Science Foundation of Jiangxi Province(Nos.20192BAB203001,20202ACBL213001,20192ACBL20013 and 20182BCB22010)+1 种基金the Youth Jinggang Scholars Program in Jiangxi Province(No.QNJG2019053)the Two Thousand Talents Program in Jiangxi Province(No.jxsq2019201068)。
文摘A novel ZnII-based metal-organic framework with the formula of{[Zn_(2)(BBIP)_(2)(NDC)_(2)]·H_(2)O}n(JXUST-5)derived from 3,5-bis(benzimidazol-1-yl)pyridine(BBIP)and 1,4-naphthalenedicarboxylic acid(H_(2)NDC)has been synthesized.The adjacent Zn^(II)ions are linked through two BBIP ligands to form a[Zn_(2)(BBIP)_(2)]secondary building unit(SBU).The neighbouring SBUs are further connected by NDC^(2-)withμ2-η^(1):η^(1)andμ2-η^(1):η^(1):η^(1)bridging modes to form a two-dimensional(2D)framework.Topological analysis shows that JXUST-5 could be simplified as an uninodal fes topology with a point symbol of{4.8^(2)}.Furthermore,the 2D framework net could be extended through C-H···πinteraction to form the three-dimensional supramolecular structure.Luminescent experiments suggest that JXUST-5 could selectively and sensitively recognize Al^(3+)and Ga^(3+)through fluorescence enhancement effect along with a relatively large red shift.The detection limits for Al^(3+)and Ga^(3+)are 0.17 and 0.69 ppm,respectively.Interestingly,the sensing process for both Al^(3+)and Ga^(3+)could be directly observed with naked eyes under 365 nm UV lamp.Notably,JXUST-5 could be recycled at least five times as a fluorescent sensor toward Al^(3+)and Ga^(3+),which is the second example of turn-on MOF based fluorescent sensor toward Ga^(3+).