This study investigated the regime-dependent predictability using convective-scale ensemble forecasts initialized with different initial condition perturbations in the Yangtze and Huai River basin(YHRB)of East China.T...This study investigated the regime-dependent predictability using convective-scale ensemble forecasts initialized with different initial condition perturbations in the Yangtze and Huai River basin(YHRB)of East China.The scale-dependent error growth(ensemble variability)and associated impact on precipitation forecasts(precipitation uncertainties)were quantitatively explored for 13 warm-season convective events that were categorized in terms of strong forcing and weak forcing.The forecast error growth in the strong-forcing regime shows a stepwise increase with increasing spatial scale,while the error growth shows a larger temporal variability with an afternoon peak appearing at smaller scales under weak forcing.This leads to the dissimilarity of precipitation uncertainty and shows a strong correlation between error growth and precipitation across spatial scales.The lateral boundary condition errors exert a quasi-linear increase on error growth with time at the larger scale,suggesting that the large-scale flow could govern the magnitude of error growth and associated precipitation uncertainties,especially for the strong-forcing regime.Further comparisons between scale-based initial error sensitivity experiments show evident scale interaction including upscale transfer of small-scale errors and downscale cascade of larger-scale errors.Specifically,small-scale errors are found to be more sensitive in the weak-forcing regime than those under strong forcing.Meanwhile,larger-scale initial errors are responsible for the error growth after 4 h and produce the precipitation uncertainties at the meso-β-scale.Consequently,these results can be used to explain underdispersion issues in convective-scale ensemble forecasts and provide feedback for ensemble design over the YHRB.展开更多
Copper(Ⅱ)-ferron(7-iodo-8-hydroxyquinoline-5-sulfonate) one-dimensional coordination polymer Na 2 n [Cu(Ferron) 2] n ·6 n H 2O was synthesized and investigated by X-ray diffraction method. The polymer exhibits a...Copper(Ⅱ)-ferron(7-iodo-8-hydroxyquinoline-5-sulfonate) one-dimensional coordination polymer Na 2 n [Cu(Ferron) 2] n ·6 n H 2O was synthesized and investigated by X-ray diffraction method. The polymer exhibits a linear structure by the bis-iodine-axial coordination to the octahedral Cu(Ⅱ) center,which is stabilized by the iodine-aromatic ring(edge and face) and iodine-iodine interactions between the polymer lines,forming a special layer structure. The complex belongs to a triclinic system,space group P 1, a =0.648 4(19) nm, b =0.654 5(19) nm, c =1.911(6) nm, α=85.42(5)°,β=85.78(5)°,γ=72.99(4)°,V =0.772(4) nm 3 and Z=1 .展开更多
A novel two-dimensional supramolecular complex [Mn（phen）（DPZDA）（H2O）]·2H2O has been synthesized by the reaction of Mn（CH3COO）2, 1,10-phenanthroline （phen） and H2DPZDA （3,5-dimethyl-pyrazine-2,6-dicarbo...A novel two-dimensional supramolecular complex [Mn（phen）（DPZDA）（H2O）]·2H2O has been synthesized by the reaction of Mn（CH3COO）2, 1,10-phenanthroline （phen） and H2DPZDA （3,5-dimethyl-pyrazine-2,6-dicarboxylic acid）. Elemental analysis, IR spectra and X-ray singlecrystal diffraction were carried out to determine the composition and crystal structure of the title complex. Crystal data： triclinic system, space group P1, a = 7.7474（13）, b = 9.3381（15）, c = 15.146（3） A, α = 93.872（3）, β= 102.451 （11 ）, y = 105.261 （ 11）°, C20H20MnN4O7, Mr = 483.34, Z = 2, F（000） = 498, V=1023.2（3）A^3, Dc=1.569 g/cm^3,μ=0.697 mm^-1, -9≤h≤9, -11≤k≤10, -18≤l≤12, R = 0.0365 and wR=0.0901 for 3585 independent reflections （Rint= 0.0165） and 2923 observed reflections （I〉 2σ（I））. Structural analysis indicates that Mn（Ⅱ） adopts a distorted octahedral geometry. The 2-D framework supramolecular structure of the title complex is constructed from hydrogen bonds and π…π interactions.展开更多
A new term was added to the well-known semi-empirical mass formula to account for the changes due to gravitational attraction between nucleons in the liquid drop, as well as, accommodates for the necessary corrections...A new term was added to the well-known semi-empirical mass formula to account for the changes due to gravitational attraction between nucleons in the liquid drop, as well as, accommodates for the necessary corrections in the binding energy of a nucleus. The results of our calculations show a straight forward evidence that the gravitational attraction bears a reasonable contribution to the binding energy. On the other hand, employing the gravitational term in the semi empirical mass formula was led to the calculation of gravitational constant at subnuclear level.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2017YFC1502103)the National Natural Science Foundation of China(Grant Nos.41430427 and 41705035)+1 种基金the China Scholarship Councilthe Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX17_0876)。
文摘This study investigated the regime-dependent predictability using convective-scale ensemble forecasts initialized with different initial condition perturbations in the Yangtze and Huai River basin(YHRB)of East China.The scale-dependent error growth(ensemble variability)and associated impact on precipitation forecasts(precipitation uncertainties)were quantitatively explored for 13 warm-season convective events that were categorized in terms of strong forcing and weak forcing.The forecast error growth in the strong-forcing regime shows a stepwise increase with increasing spatial scale,while the error growth shows a larger temporal variability with an afternoon peak appearing at smaller scales under weak forcing.This leads to the dissimilarity of precipitation uncertainty and shows a strong correlation between error growth and precipitation across spatial scales.The lateral boundary condition errors exert a quasi-linear increase on error growth with time at the larger scale,suggesting that the large-scale flow could govern the magnitude of error growth and associated precipitation uncertainties,especially for the strong-forcing regime.Further comparisons between scale-based initial error sensitivity experiments show evident scale interaction including upscale transfer of small-scale errors and downscale cascade of larger-scale errors.Specifically,small-scale errors are found to be more sensitive in the weak-forcing regime than those under strong forcing.Meanwhile,larger-scale initial errors are responsible for the error growth after 4 h and produce the precipitation uncertainties at the meso-β-scale.Consequently,these results can be used to explain underdispersion issues in convective-scale ensemble forecasts and provide feedback for ensemble design over the YHRB.
文摘Copper(Ⅱ)-ferron(7-iodo-8-hydroxyquinoline-5-sulfonate) one-dimensional coordination polymer Na 2 n [Cu(Ferron) 2] n ·6 n H 2O was synthesized and investigated by X-ray diffraction method. The polymer exhibits a linear structure by the bis-iodine-axial coordination to the octahedral Cu(Ⅱ) center,which is stabilized by the iodine-aromatic ring(edge and face) and iodine-iodine interactions between the polymer lines,forming a special layer structure. The complex belongs to a triclinic system,space group P 1, a =0.648 4(19) nm, b =0.654 5(19) nm, c =1.911(6) nm, α=85.42(5)°,β=85.78(5)°,γ=72.99(4)°,V =0.772(4) nm 3 and Z=1 .
基金Project supported by the Natural Science Foundation of Liaoning Province (No. 20052014) and Doctor Foundation of Shenyang Institute of Chemical Technology (No. 20063204)
文摘A novel two-dimensional supramolecular complex [Mn（phen）（DPZDA）（H2O）]·2H2O has been synthesized by the reaction of Mn（CH3COO）2, 1,10-phenanthroline （phen） and H2DPZDA （3,5-dimethyl-pyrazine-2,6-dicarboxylic acid）. Elemental analysis, IR spectra and X-ray singlecrystal diffraction were carried out to determine the composition and crystal structure of the title complex. Crystal data： triclinic system, space group P1, a = 7.7474（13）, b = 9.3381（15）, c = 15.146（3） A, α = 93.872（3）, β= 102.451 （11 ）, y = 105.261 （ 11）°, C20H20MnN4O7, Mr = 483.34, Z = 2, F（000） = 498, V=1023.2（3）A^3, Dc=1.569 g/cm^3,μ=0.697 mm^-1, -9≤h≤9, -11≤k≤10, -18≤l≤12, R = 0.0365 and wR=0.0901 for 3585 independent reflections （Rint= 0.0165） and 2923 observed reflections （I〉 2σ（I））. Structural analysis indicates that Mn（Ⅱ） adopts a distorted octahedral geometry. The 2-D framework supramolecular structure of the title complex is constructed from hydrogen bonds and π…π interactions.
文摘A new term was added to the well-known semi-empirical mass formula to account for the changes due to gravitational attraction between nucleons in the liquid drop, as well as, accommodates for the necessary corrections in the binding energy of a nucleus. The results of our calculations show a straight forward evidence that the gravitational attraction bears a reasonable contribution to the binding energy. On the other hand, employing the gravitational term in the semi empirical mass formula was led to the calculation of gravitational constant at subnuclear level.
