In order to study the behavior and interconnection of network devices,graphs structures are used to formulate the properties in terms of mathematical models.Mesh network(meshnet)is a LAN topology in which devices are ...In order to study the behavior and interconnection of network devices,graphs structures are used to formulate the properties in terms of mathematical models.Mesh network(meshnet)is a LAN topology in which devices are connected either directly or through some intermediate devices.These terminating and intermediate devices are considered as vertices of graph whereas wired or wireless connections among these devices are shown as edges of graph.Topological indices are used to reflect structural property of graphs in form of one real number.This structural invariant has revolutionized the field of chemistry to identify molecular descriptors of chemical compounds.These indices are extensively used for establishing relationships between the structure of nanotubes and their physico-chemical properties.In this paper a representation of sodium chloride(NaCl)is studied,because structure of NaCl is same as the Cartesian product of three paths of length exactly like a mesh network.In this way the general formula obtained in this paper can be used in chemistry as well as for any degree-based topological polynomials of three-dimensional mesh networks.展开更多
The crystal structure of the title compound [Na2(OH2)5]2+[C6H12N4H2]2-2+ [Mo7O24]6 ?4H2O, prepared from an aqueous solution of Na2MoO4 ?2H2O in the presence of MoCl3 and hexamethylene tetramine, has been determined by...The crystal structure of the title compound [Na2(OH2)5]2+[C6H12N4H2]2-2+ [Mo7O24]6 ?4H2O, prepared from an aqueous solution of Na2MoO4 ?2H2O in the presence of MoCl3 and hexamethylene tetramine, has been determined by single-crystal X-ray diffraction. The crystal is of orthorhombic, space group Pnma with a = 14.6113(2), b = 18.6833(1), c = 15.3712(2), V = 4196.14(8)3, Z = 4, Mr = 1548.13, F(000) = 3016, = 2.157 mm-1 and Dc = 2.451 g/cm3. The final R factor is 0.0526 for 3818 unique observed reflections (I > 2(I)). The structural analysis reveals that heptamolybdate anions in the title compound consist of seven edge-sharing MoO6 octahedra, and are linked into a three-dimensional framework by sodium ions and hydrogen bonds.展开更多
A series of three-dimensional ordered macroporous(3 DOM)W-TiO_(2)catalysts have been prepared through a facile colloidal crystal template method.The prepared materials characterized in detail exhibited enhanced cataly...A series of three-dimensional ordered macroporous(3 DOM)W-TiO_(2)catalysts have been prepared through a facile colloidal crystal template method.The prepared materials characterized in detail exhibited enhanced catalytic activity in aerobic oxidative desulfurization process.The experimental results indicated that the as-prepared materials possessed excellent 3 DOM structure,which is beneficial for the catalytic activity.The sample 3 DOM W-TiO_(2)-20 exhibited the highest activity in ODS process,and the sulfur removal can reach 98%in 6 h.Furthermore,the oxidative product was also analyzed in the reaction process.展开更多
This paper analyzes the compound attractor structure of a new three-dimensional autonomous chaotic system. First, it is found that there exist five equilibria in the chaotic system, and the stabilities of these equili...This paper analyzes the compound attractor structure of a new three-dimensional autonomous chaotic system. First, it is found that there exist five equilibria in the chaotic system, and the stabilities of these equilibria are discussed under a constant scalar control input parameter m. Secondly, the trajectories of the attractors on a y-z plane are examined, the reasons why these trajectories can exist or disappear are also described. Finally, the forming procedure of the different scrolls chaotic attractor is explored by computer simulations when the parameter m is varied. It is shown that the new chaotic attractor has a compound structure, it can evolve to other three-dimensional autonomous chaotic systems. The results of theoretical analysis and simulation are helpful for better understanding of other similar chaotic systems.展开更多
The finding of the compound structure of a new four-scrolls chaotic system is reported, which is obtained by merging together two symmetrical attractors. And the two symmetrical attractors are generated only by adding...The finding of the compound structure of a new four-scrolls chaotic system is reported, which is obtained by merging together two symmetrical attractors. And the two symmetrical attractors are generated only by adding a constant gain to the original system. Also, the forming procedure of the new four-scrolls chaotic attractor is explored and the relation between the constant gain and the properties of the system is given.展开更多
We propose a novel kind of compound permanent magnet synchronous machine (CPMSM), which is applicable in low-speed and high-torque situations. We first explain the structure of the CPMSM. Based on theoretically deduci...We propose a novel kind of compound permanent magnet synchronous machine (CPMSM), which is applicable in low-speed and high-torque situations. We first explain the structure of the CPMSM. Based on theoretically deducing the calculation formulae of the CPMSM electromagnetic parameters, we analyze the operating characteristics of the CPMSM, and obtain the power-angle curves and working curves. The no-load magnetic field distribution and the cogging torque are analyzed by applying the finite element method of three-dimensional (3D) magnetic fields, to determine the no-load leakage coefficient and the waveform of the cogging torque. Furthermore, the optimal parameters of the permanent magnet for reducing the cogging torque are determined. An important application target of the CPMSM is in directdrive pumping units. We have installed and tested a direct- drive pumping unit in an existing oil well. Test results show that the power consumption of the direct-drive pumping unit driven by CPMSM is 61.1% of that of the beam-pumping unit, and that the floor space and weight are only 50% of those of a beam-pumping unit. The noise output does not exceed 58 dB in a range of 1 m around the machine when the machine is 1.5 m from the ground.展开更多
To address the problem that granular compound fertilizer is prone to agglomeration during mechanized direct seeding of oilseed rape in the middle and lower reaches of the Yangtze River,which causes clogging of the fer...To address the problem that granular compound fertilizer is prone to agglomeration during mechanized direct seeding of oilseed rape in the middle and lower reaches of the Yangtze River,which causes clogging of the fertilizer discharger and leads to a reduction in the uniformity and stability of fertilizer discharge,research on the crushing mechanism of caking compound fertilizer was performed.Considering that it is difficult to measure the bonding force between caking fertilizer particles directly,a simulation model of caking composite fertilizer was established with the bonding model in EDEM discrete element software.To decrease error between the simulation and physical test results,the normal contact stiffness,tangential contact stiffness,critical normal stress,critical tangential stress,bonding radius,and other parameters of the bonding model of caking composite fertilizer were calibrated.The three-dimensional structure of the caking composite fertilizer was obtained via three-dimensional scanning,the critical crushing displacement and critical crushing force of the caking composite fertilizer were measured via compression testing with a mass spectrometer,and the optimal parameter combination of the bonding model was determined via EDEM discrete element simulation of the Plackett-Burman test,steepest ascent test,and Box-Behnken test.The results of the simulated compression tests under the optimal parameter combination show that the relative errors of the critical crushing displacement and critical crushing force with respect to the physical test results were 0.296%and 0.343%,respectively.Using the crushing rate of caking compound fertilizer as an evaluation index,the feasibility of the calibrated parameters was verified for a four-head spiral two-row fertilizer discharger installed in a direct seeding machine for oilseed rape.The results show that the relative errors of the caking fertilizer crushing rates from the simulation relative to those of the bench and field tests were 5.81%and 5.06%,respectively,indicating that the calibration parameters of the discrete element model were accurate and could be used for parameter analysis of caking fertilizer with a discrete element model.These results can provide a reference for the structural optimization of fertilizer discharger crushing of caking fertilizer of direct seeding machine for oilseed rape.展开更多
In this study,a novel three-dimensional(3D)-OMm-Co_(3)O_(4)/SiO_(2)-0.5AP(OMm=ordered macro–meso porous,AP=aluminum phosphate)monolithic catalyst was for the first time constructed successfully with the hierarchical ...In this study,a novel three-dimensional(3D)-OMm-Co_(3)O_(4)/SiO_(2)-0.5AP(OMm=ordered macro–meso porous,AP=aluminum phosphate)monolithic catalyst was for the first time constructed successfully with the hierarchical Co-phyllosilicate ultrathin nanosheets growth on the surface of 3D printed ordered macropore–mesoporous SiO_(2)support.On the one hand,we discovered that the construction of ordered macropore–mesoporous structures is beneficial to the diffusion and adsorption of reactants,intermediates,and products.On the other hand,the formation of hierarchical Co-phyllosilicate ultrathin nanosheets could provide more active Co&+species,abundant acid sites,and active oxygen.The above factors are in favor of improving the catalytic performance of benzene oxidation,and then a 3D-OMm-Co_(3)O_(4)/SiO_(2)-0.5AP catalyst exhibited the superior catalytic activity.To explore the effect of catalysts structure and morphology,various Co-based catalysts were also constructed.Simultaneously,the 3D-OMm-Co_(3)O_(4)/SiO_(2)-0.5AP catalyst has excellent catalytic performance,water resistance,and thermal stability in the catalytic combustion of benzene due to the strong interactions between Co&+species and SiO_(2)in the phyllosilicate.Therefore,this study proposes a new catalyst synthesis method through 3D printing,and presents considerable prospects for the removal of VOCs from industrial applications.展开更多
文摘In order to study the behavior and interconnection of network devices,graphs structures are used to formulate the properties in terms of mathematical models.Mesh network(meshnet)is a LAN topology in which devices are connected either directly or through some intermediate devices.These terminating and intermediate devices are considered as vertices of graph whereas wired or wireless connections among these devices are shown as edges of graph.Topological indices are used to reflect structural property of graphs in form of one real number.This structural invariant has revolutionized the field of chemistry to identify molecular descriptors of chemical compounds.These indices are extensively used for establishing relationships between the structure of nanotubes and their physico-chemical properties.In this paper a representation of sodium chloride(NaCl)is studied,because structure of NaCl is same as the Cartesian product of three paths of length exactly like a mesh network.In this way the general formula obtained in this paper can be used in chemistry as well as for any degree-based topological polynomials of three-dimensional mesh networks.
基金This work was supported by Chinese Academy of Sciences the State Education Ministry+1 种基金 the State Personnel Ministry the NSFC (20073048)
文摘The crystal structure of the title compound [Na2(OH2)5]2+[C6H12N4H2]2-2+ [Mo7O24]6 ?4H2O, prepared from an aqueous solution of Na2MoO4 ?2H2O in the presence of MoCl3 and hexamethylene tetramine, has been determined by single-crystal X-ray diffraction. The crystal is of orthorhombic, space group Pnma with a = 14.6113(2), b = 18.6833(1), c = 15.3712(2), V = 4196.14(8)3, Z = 4, Mr = 1548.13, F(000) = 3016, = 2.157 mm-1 and Dc = 2.451 g/cm3. The final R factor is 0.0526 for 3818 unique observed reflections (I > 2(I)). The structural analysis reveals that heptamolybdate anions in the title compound consist of seven edge-sharing MoO6 octahedra, and are linked into a three-dimensional framework by sodium ions and hydrogen bonds.
基金the financial support from the National Natural Science Foundation of China(Nos.21722604 and 21776116)China Postdoctoral Science Foundation(2020M671365)+2 种基金Jiangsu Postdoctoral Research Funding Program(No.2021K343C)Natural Science Foundation of Jiangsu Province(No.BK20190243)the Society Development Fund of Zhenjiang City(SH2020020)。
文摘A series of three-dimensional ordered macroporous(3 DOM)W-TiO_(2)catalysts have been prepared through a facile colloidal crystal template method.The prepared materials characterized in detail exhibited enhanced catalytic activity in aerobic oxidative desulfurization process.The experimental results indicated that the as-prepared materials possessed excellent 3 DOM structure,which is beneficial for the catalytic activity.The sample 3 DOM W-TiO_(2)-20 exhibited the highest activity in ODS process,and the sulfur removal can reach 98%in 6 h.Furthermore,the oxidative product was also analyzed in the reaction process.
文摘This paper analyzes the compound attractor structure of a new three-dimensional autonomous chaotic system. First, it is found that there exist five equilibria in the chaotic system, and the stabilities of these equilibria are discussed under a constant scalar control input parameter m. Secondly, the trajectories of the attractors on a y-z plane are examined, the reasons why these trajectories can exist or disappear are also described. Finally, the forming procedure of the different scrolls chaotic attractor is explored by computer simulations when the parameter m is varied. It is shown that the new chaotic attractor has a compound structure, it can evolve to other three-dimensional autonomous chaotic systems. The results of theoretical analysis and simulation are helpful for better understanding of other similar chaotic systems.
文摘The finding of the compound structure of a new four-scrolls chaotic system is reported, which is obtained by merging together two symmetrical attractors. And the two symmetrical attractors are generated only by adding a constant gain to the original system. Also, the forming procedure of the new four-scrolls chaotic attractor is explored and the relation between the constant gain and the properties of the system is given.
基金Project (No. 50607016) supported by the National Natural ScienceFoundation of China
文摘We propose a novel kind of compound permanent magnet synchronous machine (CPMSM), which is applicable in low-speed and high-torque situations. We first explain the structure of the CPMSM. Based on theoretically deducing the calculation formulae of the CPMSM electromagnetic parameters, we analyze the operating characteristics of the CPMSM, and obtain the power-angle curves and working curves. The no-load magnetic field distribution and the cogging torque are analyzed by applying the finite element method of three-dimensional (3D) magnetic fields, to determine the no-load leakage coefficient and the waveform of the cogging torque. Furthermore, the optimal parameters of the permanent magnet for reducing the cogging torque are determined. An important application target of the CPMSM is in directdrive pumping units. We have installed and tested a direct- drive pumping unit in an existing oil well. Test results show that the power consumption of the direct-drive pumping unit driven by CPMSM is 61.1% of that of the beam-pumping unit, and that the floor space and weight are only 50% of those of a beam-pumping unit. The noise output does not exceed 58 dB in a range of 1 m around the machine when the machine is 1.5 m from the ground.
基金supported by the China Agricultural Research System of MOF and MARA(NO:CARS-12).
文摘To address the problem that granular compound fertilizer is prone to agglomeration during mechanized direct seeding of oilseed rape in the middle and lower reaches of the Yangtze River,which causes clogging of the fertilizer discharger and leads to a reduction in the uniformity and stability of fertilizer discharge,research on the crushing mechanism of caking compound fertilizer was performed.Considering that it is difficult to measure the bonding force between caking fertilizer particles directly,a simulation model of caking composite fertilizer was established with the bonding model in EDEM discrete element software.To decrease error between the simulation and physical test results,the normal contact stiffness,tangential contact stiffness,critical normal stress,critical tangential stress,bonding radius,and other parameters of the bonding model of caking composite fertilizer were calibrated.The three-dimensional structure of the caking composite fertilizer was obtained via three-dimensional scanning,the critical crushing displacement and critical crushing force of the caking composite fertilizer were measured via compression testing with a mass spectrometer,and the optimal parameter combination of the bonding model was determined via EDEM discrete element simulation of the Plackett-Burman test,steepest ascent test,and Box-Behnken test.The results of the simulated compression tests under the optimal parameter combination show that the relative errors of the critical crushing displacement and critical crushing force with respect to the physical test results were 0.296%and 0.343%,respectively.Using the crushing rate of caking compound fertilizer as an evaluation index,the feasibility of the calibrated parameters was verified for a four-head spiral two-row fertilizer discharger installed in a direct seeding machine for oilseed rape.The results show that the relative errors of the caking fertilizer crushing rates from the simulation relative to those of the bench and field tests were 5.81%and 5.06%,respectively,indicating that the calibration parameters of the discrete element model were accurate and could be used for parameter analysis of caking fertilizer with a discrete element model.These results can provide a reference for the structural optimization of fertilizer discharger crushing of caking fertilizer of direct seeding machine for oilseed rape.
基金the LICP Cooperation Foundation for Young Scholars(No.HZJJ21-02)the National Natural Science Foundation of China(Nos.52070182 and 51908535)+2 种基金the DNL Cooperation Found,Chinese Academy of Sciences(No.DNL202004)Province Natural Science Foundation of GanSu(Nos.20JR10RA053 and 20JR10RA046)Major Program of the Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences(No.ZYFZFX-10).
文摘In this study,a novel three-dimensional(3D)-OMm-Co_(3)O_(4)/SiO_(2)-0.5AP(OMm=ordered macro–meso porous,AP=aluminum phosphate)monolithic catalyst was for the first time constructed successfully with the hierarchical Co-phyllosilicate ultrathin nanosheets growth on the surface of 3D printed ordered macropore–mesoporous SiO_(2)support.On the one hand,we discovered that the construction of ordered macropore–mesoporous structures is beneficial to the diffusion and adsorption of reactants,intermediates,and products.On the other hand,the formation of hierarchical Co-phyllosilicate ultrathin nanosheets could provide more active Co&+species,abundant acid sites,and active oxygen.The above factors are in favor of improving the catalytic performance of benzene oxidation,and then a 3D-OMm-Co_(3)O_(4)/SiO_(2)-0.5AP catalyst exhibited the superior catalytic activity.To explore the effect of catalysts structure and morphology,various Co-based catalysts were also constructed.Simultaneously,the 3D-OMm-Co_(3)O_(4)/SiO_(2)-0.5AP catalyst has excellent catalytic performance,water resistance,and thermal stability in the catalytic combustion of benzene due to the strong interactions between Co&+species and SiO_(2)in the phyllosilicate.Therefore,this study proposes a new catalyst synthesis method through 3D printing,and presents considerable prospects for the removal of VOCs from industrial applications.
