Polygonal finite elements remain an attractive option in finite element analysis due to their flexibility in modelingarbitrary shapes compared to triangles.In this study,a pentagonal membrane element was developed wit...Polygonal finite elements remain an attractive option in finite element analysis due to their flexibility in modelingarbitrary shapes compared to triangles.In this study,a pentagonal membrane element was developed with thestrain approach for the first time.The element possesses invariance,and the equilibrium constraint was appliedto the assumed strain field using corrective coefficients.Inspired by the advancing front technique,a pentagonalmesh was generated,and the mesh quality was enhanced with Laplacian smoothing.The performance of thedeveloped pentagonal element was assessed in a few numerical tests,and the results revealed its suitability inmodeling the bending of beams.Besides,the numerical results are enhanced when pentagonal elements are usedin mesh transitions along boundaries to smoothen curved edges and capture distributed loads.展开更多
The petroleum industry has a complex,inflexible and challenging supply chain(SC)that impacts both the national economy as well as people’s daily lives with a range of services,including transportation,heating,electri...The petroleum industry has a complex,inflexible and challenging supply chain(SC)that impacts both the national economy as well as people’s daily lives with a range of services,including transportation,heating,electricity,lubricants,as well as chemicals and petrochemicals.In the petroleum industry,supply chain management presents several challenges,especially in the logistics sector,that are not found in other industries.In addition,logistical challenges contribute significantly to the cost of oil.Uncertainty regarding customer demand and supply significantly affects SC networks.Hence,SC flexibility can be maintained by addressing uncertainty.On the other hand,in the real world,decision-making challenges are often ambiguous or vague.In some cases,measurements are incorrect owing to measurement errors,instrument faults,etc.,which lead to a pentagonal fuzzy number(PFN)which is the extension of a fuzzy number.Therefore,it is necessary to develop quantitative models to optimize logistics operations and supply chain networks.This study proposed a linear programming model under an uncertain environment.The model minimizes the cost along the refineries,depots,multimode transport and demand nodes.Further developed pentagonal fuzzy optimization,an alternative approach is developed to solve the downstream supply chain using themixed-integer linear programming(MILP)model to obtain a feasible solution to the fuzzy transportation cost problem.In this model,the coefficient of the transportation costs and parameters is assumed to be a pentagonal fuzzy number.Furthermore,defuzzification is performed using an accuracy function.To validate the model and technique and feasibility solution,an illustrative example of the oil and gas SC is considered,providing improved results compared with existing techniques and demonstrating its ability to benefit petroleum companies is the objective of this study.展开更多
Intrinsic topological defect engineering has been proven as a promising strategy to elevate the electrocatalytic activity of carbon materials.However,the controllable construction of high-density and specific topologi...Intrinsic topological defect engineering has been proven as a promising strategy to elevate the electrocatalytic activity of carbon materials.However,the controllable construction of high-density and specific topological defects in carbon frameworks to reveal the relationship between reactivity and defect structure remains a challenging task.Herein,the intrinsic pentagon carbon sites that can favor electron overflow and enhance their binding affinity towards the intermediates of catalytic reaction are firstly presented by the work function and the p-band center calculations.To experimentally verify this,the cage-opening reaction of fullerene is proposed and utilized for synthesizing carbon quantum dots with specific pentagon configuration(CQDs-P),subsequently utilizing CQDs-P to modulate the micro-scale defect density of three-dimensional reduced graphene oxide(rGO)viaπ-πinteractions.The multiple spatial-scale rGO-conjugated CQDs-P structure simultaneously possesses abundant pentagon and edge defects as catalytic active sites and long-range-orderedπelectron delocalization system as conductive network.The defects-rich CQDs-P/rGO-4 all-carbon-based catalyst exhibits superb catalytic activity for triiodide reduction reaction with a high photoelectric conversion efficiency of 8.40%,superior to the Pt reference(7.97%).Theoretical calculations suggest that pentagon defects in the carbon frameworks can promote charge transfer and modulate the adsorption/dissociation behavior of the reaction intermediates,thus enhancing the electrocatalytic activity of the catalyst.This work confirms the role of intrinsic pentagon defects in catalytic reactions and provides a new insight into the synthesis of defects-rich carbon catalysts.展开更多
This paper describes the multiband behaviour as well as the response for dielectric loading of a pentagonal fractal patch antenna designed at frequency f = 2.45 GHz. The proposed antenna shape has been obtained by int...This paper describes the multiband behaviour as well as the response for dielectric loading of a pentagonal fractal patch antenna designed at frequency f = 2.45 GHz. The proposed antenna shape has been obtained by introducing slots in a pentagonal patch antenna up to second iteration. Detailed design steps and results of the designs are studied and investigated in this paper. Simulated and measured results reveal that the antenna will be operated at three different frequency bands—2.17 GHz, 3.56 GHz, and 7.93 GHz with acceptable performances (i.e. VSWR < 2). The measured results for the antennas are in good agreement with simulated results. The proposed antenna maintains good radiation pattern with gain. However dielectric loading increases its radiation efficiency at the cost of significant decrease in gain and directivity.展开更多
Microscope observations of normal human ke- ratinocytes (NHK) propagated in a serum-free medium reveal a high frequency (>70%) of pentagonally-shaped colonies over a wide range of colony sizes that persist over man...Microscope observations of normal human ke- ratinocytes (NHK) propagated in a serum-free medium reveal a high frequency (>70%) of pentagonally-shaped colonies over a wide range of colony sizes that persist over many sequential cell generations. NHK colonies derived from sin- gle cell isolates also display pentagonal symme- try as confirmed by a photographic technique known as “Markham Rotation”. The generality of pentagonal cellular morphology was extended to observations in situ of pentagonally-shaped basal layer epidermal cells of normal human epidermis, monolayer cultures of normal and immortalized keratinocytes, several different ch- ick embryo cells, and in previously published photographs. Statistical methods were applied that differentiate planar close-packing of polygonal configurations observed in living cellular system from several examples of non-living cellular aggregates that were produced spontaneously in nature or in the laboratory under defined physico-chemical conditions.展开更多
Based on some necessary conditions for double pyramidal central configurations with a concave pentagonal base, for any given ratio of masses, the existence and uniqueness of a class of double pyramidal central configu...Based on some necessary conditions for double pyramidal central configurations with a concave pentagonal base, for any given ratio of masses, the existence and uniqueness of a class of double pyramidal central configurations with a concave pentagonal base in 7-body problems are proved and the range of the ratio between radius and half-height is obtained, within which the 7 bodies involved form a central configuration or form uniquely a central configuration.展开更多
为了解决Duval Pentagon1法不能表征各种变压器故障模式可信度的问题,提出了一种基于空间分析理论改进的方法。首先,采用核密度估计(kernel density estimation,KDE)方法对各种变压器故障模式数据进行空间分布密度分析;其次,应用B样条...为了解决Duval Pentagon1法不能表征各种变压器故障模式可信度的问题,提出了一种基于空间分析理论改进的方法。首先,采用核密度估计(kernel density estimation,KDE)方法对各种变压器故障模式数据进行空间分布密度分析;其次,应用B样条理论构造各种变压器故障模式密度曲面;最后,利用空间叠置分析方法实现变压器故障模式识别。实例分析结果表明:与Duval Pentagon1法相比,改进后的Duval Pentagon1法的总体诊断准确率提升了8.42%,并且能够定量地表征各种变压器故障模式可信度。研究结果可为变压器油中溶解气体图形分析方法的改进提供参考。展开更多
In this paper the percolation behavior with a specific concentration of the defects was discussed on the twodimensional graphene lattice. The percolation threshold is determined by a numerical method with a high degre...In this paper the percolation behavior with a specific concentration of the defects was discussed on the twodimensional graphene lattice. The percolation threshold is determined by a numerical method with a high degree of accuracy. This method is also suitable for locating the percolation critical point on other crystalline structures. Through investigating the evolution of the largest cluster size and the cluster sizes distribution, we find that under various lattice sizes and concentrations of pentagon-heptagon defects there is no apparent change for the percolation properties in graphene lattice.展开更多
基金supported by the Research Management Centre(RMC)of Multimedia University,Malaysia(Grant No.MMUI/220016).
文摘Polygonal finite elements remain an attractive option in finite element analysis due to their flexibility in modelingarbitrary shapes compared to triangles.In this study,a pentagonal membrane element was developed with thestrain approach for the first time.The element possesses invariance,and the equilibrium constraint was appliedto the assumed strain field using corrective coefficients.Inspired by the advancing front technique,a pentagonalmesh was generated,and the mesh quality was enhanced with Laplacian smoothing.The performance of thedeveloped pentagonal element was assessed in a few numerical tests,and the results revealed its suitability inmodeling the bending of beams.Besides,the numerical results are enhanced when pentagonal elements are usedin mesh transitions along boundaries to smoothen curved edges and capture distributed loads.
文摘The petroleum industry has a complex,inflexible and challenging supply chain(SC)that impacts both the national economy as well as people’s daily lives with a range of services,including transportation,heating,electricity,lubricants,as well as chemicals and petrochemicals.In the petroleum industry,supply chain management presents several challenges,especially in the logistics sector,that are not found in other industries.In addition,logistical challenges contribute significantly to the cost of oil.Uncertainty regarding customer demand and supply significantly affects SC networks.Hence,SC flexibility can be maintained by addressing uncertainty.On the other hand,in the real world,decision-making challenges are often ambiguous or vague.In some cases,measurements are incorrect owing to measurement errors,instrument faults,etc.,which lead to a pentagonal fuzzy number(PFN)which is the extension of a fuzzy number.Therefore,it is necessary to develop quantitative models to optimize logistics operations and supply chain networks.This study proposed a linear programming model under an uncertain environment.The model minimizes the cost along the refineries,depots,multimode transport and demand nodes.Further developed pentagonal fuzzy optimization,an alternative approach is developed to solve the downstream supply chain using themixed-integer linear programming(MILP)model to obtain a feasible solution to the fuzzy transportation cost problem.In this model,the coefficient of the transportation costs and parameters is assumed to be a pentagonal fuzzy number.Furthermore,defuzzification is performed using an accuracy function.To validate the model and technique and feasibility solution,an illustrative example of the oil and gas SC is considered,providing improved results compared with existing techniques and demonstrating its ability to benefit petroleum companies is the objective of this study.
基金partly supported by the National Natural Science Foundation of China(22078052)the National Key R&D Program of China(2022YFB4101602)the Fundamental Research Funds for the Central Universities(DUT22LAB612)。
文摘Intrinsic topological defect engineering has been proven as a promising strategy to elevate the electrocatalytic activity of carbon materials.However,the controllable construction of high-density and specific topological defects in carbon frameworks to reveal the relationship between reactivity and defect structure remains a challenging task.Herein,the intrinsic pentagon carbon sites that can favor electron overflow and enhance their binding affinity towards the intermediates of catalytic reaction are firstly presented by the work function and the p-band center calculations.To experimentally verify this,the cage-opening reaction of fullerene is proposed and utilized for synthesizing carbon quantum dots with specific pentagon configuration(CQDs-P),subsequently utilizing CQDs-P to modulate the micro-scale defect density of three-dimensional reduced graphene oxide(rGO)viaπ-πinteractions.The multiple spatial-scale rGO-conjugated CQDs-P structure simultaneously possesses abundant pentagon and edge defects as catalytic active sites and long-range-orderedπelectron delocalization system as conductive network.The defects-rich CQDs-P/rGO-4 all-carbon-based catalyst exhibits superb catalytic activity for triiodide reduction reaction with a high photoelectric conversion efficiency of 8.40%,superior to the Pt reference(7.97%).Theoretical calculations suggest that pentagon defects in the carbon frameworks can promote charge transfer and modulate the adsorption/dissociation behavior of the reaction intermediates,thus enhancing the electrocatalytic activity of the catalyst.This work confirms the role of intrinsic pentagon defects in catalytic reactions and provides a new insight into the synthesis of defects-rich carbon catalysts.
文摘This paper describes the multiband behaviour as well as the response for dielectric loading of a pentagonal fractal patch antenna designed at frequency f = 2.45 GHz. The proposed antenna shape has been obtained by introducing slots in a pentagonal patch antenna up to second iteration. Detailed design steps and results of the designs are studied and investigated in this paper. Simulated and measured results reveal that the antenna will be operated at three different frequency bands—2.17 GHz, 3.56 GHz, and 7.93 GHz with acceptable performances (i.e. VSWR < 2). The measured results for the antennas are in good agreement with simulated results. The proposed antenna maintains good radiation pattern with gain. However dielectric loading increases its radiation efficiency at the cost of significant decrease in gain and directivity.
文摘Microscope observations of normal human ke- ratinocytes (NHK) propagated in a serum-free medium reveal a high frequency (>70%) of pentagonally-shaped colonies over a wide range of colony sizes that persist over many sequential cell generations. NHK colonies derived from sin- gle cell isolates also display pentagonal symme- try as confirmed by a photographic technique known as “Markham Rotation”. The generality of pentagonal cellular morphology was extended to observations in situ of pentagonally-shaped basal layer epidermal cells of normal human epidermis, monolayer cultures of normal and immortalized keratinocytes, several different ch- ick embryo cells, and in previously published photographs. Statistical methods were applied that differentiate planar close-packing of polygonal configurations observed in living cellular system from several examples of non-living cellular aggregates that were produced spontaneously in nature or in the laboratory under defined physico-chemical conditions.
基金Natural Science Foundation of China (No.19871096)
文摘Based on some necessary conditions for double pyramidal central configurations with a concave pentagonal base, for any given ratio of masses, the existence and uniqueness of a class of double pyramidal central configurations with a concave pentagonal base in 7-body problems are proved and the range of the ratio between radius and half-height is obtained, within which the 7 bodies involved form a central configuration or form uniquely a central configuration.
文摘In this paper the percolation behavior with a specific concentration of the defects was discussed on the twodimensional graphene lattice. The percolation threshold is determined by a numerical method with a high degree of accuracy. This method is also suitable for locating the percolation critical point on other crystalline structures. Through investigating the evolution of the largest cluster size and the cluster sizes distribution, we find that under various lattice sizes and concentrations of pentagon-heptagon defects there is no apparent change for the percolation properties in graphene lattice.
