Aiming at the problem of low accuracy of interpolation error calculation of existing NURBS curves, an approximate method for the distance between a point and a NURBS interpolation curve is proposed while satisfying th...Aiming at the problem of low accuracy of interpolation error calculation of existing NURBS curves, an approximate method for the distance between a point and a NURBS interpolation curve is proposed while satisfying the accuracy of the solution. Firstly, the minimum parameter interval of the node vector corresponding to the data point under test in the original data point sequence is determined, and the parameter interval is subdivided according to the corresponding step size, and the corresponding parameter value is obtained. Secondly, the distance from the measured point to the NURBS curve is calculated, and the nearest distance is found out. The node interval is subdivided again on one side of the nearest distance. Finally, the distance between the data point to be measured and each subdivision point is calculated again, and the minimum distance is taken as the interpolation error between the point and the NURBS curve. The simulation results of actual tool position data show that this method can more accurately obtain the error of spatial NURBS interpolation curve.展开更多
Achieving efficient adsorption and separation of C_(2)H_(2)/CO_(2)mixtures is a goal that people have always pursued to improve the situation of high energy consumption brought by traditional separation technologies i...Achieving efficient adsorption and separation of C_(2)H_(2)/CO_(2)mixtures is a goal that people have always pursued to improve the situation of high energy consumption brought by traditional separation technologies in industry today.High-nuclearity metal cluster-based MOFs with different functionalities are promising for this separation,but it is a complicated and difficult task to precisely control their structures.The strategy of pore-space partition(PSP)is a powerful way to construct this type MOFs,which has the characteristic of isostructural relationship,and can be resulted in a similar performance for them.Therefore,it is an interesting work to explore the effect of MOFs property by adjusting the size of PSP dividers.Herein,three tetranuclear Cu(Ⅱ)cluster-based MOFs(FJU-112/113/114)with dual functionalities has been successfully obtained by PSP strategy with various lengths of divider units.With the highest microporosity and unique functional site,FJU-114 realized a good improvement in the adsorption and separation performance of C_(2)H_(2)/CO_(2).The gas adsorption and lab-scale C_(2)H_(2)/CO_(2)breakthrough experiments demonstrated that FJU-114 exhibits the highest adsorption uptake of 77 cm^(3)/g for C_(2)H_(2),and shows the best separation factor of 4.2 among three MOFs.The GCMC simulation reveals that a stronger adsorption binding site of C_(2)H_(2)in FJU-114a located in the cage II near the unchanged tetranuclear copper node,combined with its high microporosity to achieve the effect of dual functionalities for the improvement performance of C_(2)H_(2)adsorption and separation.展开更多
Hydrogen-bonded organic frameworks(HOFs)are a promising candidate for optical sensing,but the lack of effective design strategies poses significant challenges to the construction of HOFs for organic acid sensing.In th...Hydrogen-bonded organic frameworks(HOFs)are a promising candidate for optical sensing,but the lack of effective design strategies poses significant challenges to the construction of HOFs for organic acid sensing.In this work,the first HOF for organic acid sensing is reported by constructing a multiplepyridine carbazole-based dense HOF,namely HOF-FJU-206,from a tripyridine-carbazole molecular 3,6-bis(pyridin-4-yl)-9-(4-(pyridin-4-yl)phenyl)-9H-carbazole(CPPY)with carbazole center for luminescence,pyridyl sites for its responsive of hydrogen proton,and narrow channels in the dense framework for the diffusion of hydrogen protons.HOF-FJU-206 exhibits differential responsively fluorescence sensing and recovery properties to formic,acetic,and propionic acids with different molecular sizes and p Kavalue(acid dissociation constant).The dissociation degree of various acids can be determined by analyzing the slope of changes in both peak wavelength and intensity of in-situ fluorescence,which easily enables the dual-corrective recognition of different acids.The varying degree of protonation at pyridine sites is proved to be the reason for differential sensing of various acids,as demonstrated by1H NMR spectra,X-ray photoelectron spectroscopy(XPS)characterization,and modeling studies.展开更多
Acetylene purification from methane is challenging in the field of porous organic polymers(POPs).Herein,we have provided one-pot Ullmann coupling reaction to synthesize a series of POPs with rich N-sites,named FJU-POP...Acetylene purification from methane is challenging in the field of porous organic polymers(POPs).Herein,we have provided one-pot Ullmann coupling reaction to synthesize a series of POPs with rich N-sites,named FJU-POP-n,wherein the low-cost and non-toxic Cu(acac)2 and environmental-friendly glycerol are employed as catalyst and solvent,respectively.展开更多
Flexible-robust hydrogen-bonded organic frameworks(HOFs)are attracting increasing interest due to their excellent separation performance for important industrial gases,but the construction remains challenging.Herein,a...Flexible-robust hydrogen-bonded organic frameworks(HOFs)are attracting increasing interest due to their excellent separation performance for important industrial gases,but the construction remains challenging.Herein,a sticked-layer strategy is first proposed to construct a flexible-robust HOF,HOFFJU-8,from a donor(D)–π–acceptor(A)molecule 4,4′,4″,4‴-(pyrrolo[3,2-b]pyrrole-1,2,4,5-tetrayl)tetrabenzonitrile(DP-4CN).HOF-FJU-8 is amicroporous three-dimensional framework composed of two kinds of DP-4CN molecules,one acting as building units for the two-dimensional layer via C≡N···H–C hydrogen bond dimers and another as the sticks to link the layers along channels through D–Aπ···πinteractions.The activated framework HOF-FJU-8a possesses flexible-robust pore characteristics,as determined by the gas adsorption and in situ gas-loaded powder X-ray diffraction.HOF-FJU-8a exhibits adaptive adsorption and stronger binding affinity to C_(2)H_(2)rather than CO_(2)due to the flexible-robust nature,which can effectively separate acetylene and carbon dioxide mixtures.展开更多
文摘Aiming at the problem of low accuracy of interpolation error calculation of existing NURBS curves, an approximate method for the distance between a point and a NURBS interpolation curve is proposed while satisfying the accuracy of the solution. Firstly, the minimum parameter interval of the node vector corresponding to the data point under test in the original data point sequence is determined, and the parameter interval is subdivided according to the corresponding step size, and the corresponding parameter value is obtained. Secondly, the distance from the measured point to the NURBS curve is calculated, and the nearest distance is found out. The node interval is subdivided again on one side of the nearest distance. Finally, the distance between the data point to be measured and each subdivision point is calculated again, and the minimum distance is taken as the interpolation error between the point and the NURBS curve. The simulation results of actual tool position data show that this method can more accurately obtain the error of spatial NURBS interpolation curve.
基金financially supported by the National Natural Science Foundation of China(Nos.21975044,21971038,21922810 and 22271046)the Fujian Provincial Department of Science and Technology(Nos.2023J01355,2023J011106 and 2022R1022001).
文摘Achieving efficient adsorption and separation of C_(2)H_(2)/CO_(2)mixtures is a goal that people have always pursued to improve the situation of high energy consumption brought by traditional separation technologies in industry today.High-nuclearity metal cluster-based MOFs with different functionalities are promising for this separation,but it is a complicated and difficult task to precisely control their structures.The strategy of pore-space partition(PSP)is a powerful way to construct this type MOFs,which has the characteristic of isostructural relationship,and can be resulted in a similar performance for them.Therefore,it is an interesting work to explore the effect of MOFs property by adjusting the size of PSP dividers.Herein,three tetranuclear Cu(Ⅱ)cluster-based MOFs(FJU-112/113/114)with dual functionalities has been successfully obtained by PSP strategy with various lengths of divider units.With the highest microporosity and unique functional site,FJU-114 realized a good improvement in the adsorption and separation performance of C_(2)H_(2)/CO_(2).The gas adsorption and lab-scale C_(2)H_(2)/CO_(2)breakthrough experiments demonstrated that FJU-114 exhibits the highest adsorption uptake of 77 cm^(3)/g for C_(2)H_(2),and shows the best separation factor of 4.2 among three MOFs.The GCMC simulation reveals that a stronger adsorption binding site of C_(2)H_(2)in FJU-114a located in the cage II near the unchanged tetranuclear copper node,combined with its high microporosity to achieve the effect of dual functionalities for the improvement performance of C_(2)H_(2)adsorption and separation.
基金supported by the National Natural Science Foundation of China(Nos.22271046,21971038,21975044)the Fujian Provincial Department of Science and Technology(No.2019L3004)the Foundation of National Key Laboratory of Human Factors Engineering(No.HFNKL2023W04)。
文摘Hydrogen-bonded organic frameworks(HOFs)are a promising candidate for optical sensing,but the lack of effective design strategies poses significant challenges to the construction of HOFs for organic acid sensing.In this work,the first HOF for organic acid sensing is reported by constructing a multiplepyridine carbazole-based dense HOF,namely HOF-FJU-206,from a tripyridine-carbazole molecular 3,6-bis(pyridin-4-yl)-9-(4-(pyridin-4-yl)phenyl)-9H-carbazole(CPPY)with carbazole center for luminescence,pyridyl sites for its responsive of hydrogen proton,and narrow channels in the dense framework for the diffusion of hydrogen protons.HOF-FJU-206 exhibits differential responsively fluorescence sensing and recovery properties to formic,acetic,and propionic acids with different molecular sizes and p Kavalue(acid dissociation constant).The dissociation degree of various acids can be determined by analyzing the slope of changes in both peak wavelength and intensity of in-situ fluorescence,which easily enables the dual-corrective recognition of different acids.The varying degree of protonation at pyridine sites is proved to be the reason for differential sensing of various acids,as demonstrated by1H NMR spectra,X-ray photoelectron spectroscopy(XPS)characterization,and modeling studies.
基金This work was financially supported by the National Natural Science Foundation of China(grant nos.21975044,21971038 and 219722810)Fujian Provincial Department of Science and Technology(2018J07001,2019L3004,2019H6012 and 2021H0062).
文摘Acetylene purification from methane is challenging in the field of porous organic polymers(POPs).Herein,we have provided one-pot Ullmann coupling reaction to synthesize a series of POPs with rich N-sites,named FJU-POP-n,wherein the low-cost and non-toxic Cu(acac)2 and environmental-friendly glycerol are employed as catalyst and solvent,respectively.
基金supported by the National Natural Science Foundation of China(grant nos.22271046,21971038,and 21975044)the Fujian Provincial Department of Science and Technology(grant no.2019L3004).
文摘Flexible-robust hydrogen-bonded organic frameworks(HOFs)are attracting increasing interest due to their excellent separation performance for important industrial gases,but the construction remains challenging.Herein,a sticked-layer strategy is first proposed to construct a flexible-robust HOF,HOFFJU-8,from a donor(D)–π–acceptor(A)molecule 4,4′,4″,4‴-(pyrrolo[3,2-b]pyrrole-1,2,4,5-tetrayl)tetrabenzonitrile(DP-4CN).HOF-FJU-8 is amicroporous three-dimensional framework composed of two kinds of DP-4CN molecules,one acting as building units for the two-dimensional layer via C≡N···H–C hydrogen bond dimers and another as the sticks to link the layers along channels through D–Aπ···πinteractions.The activated framework HOF-FJU-8a possesses flexible-robust pore characteristics,as determined by the gas adsorption and in situ gas-loaded powder X-ray diffraction.HOF-FJU-8a exhibits adaptive adsorption and stronger binding affinity to C_(2)H_(2)rather than CO_(2)due to the flexible-robust nature,which can effectively separate acetylene and carbon dioxide mixtures.
