Synchronization of networked phase oscillators depends essentially on the correlation between the topological structure of the graph and the dynamical property of the elements. We propose the concept of ＇reduced freq...Synchronization of networked phase oscillators depends essentially on the correlation between the topological structure of the graph and the dynamical property of the elements. We propose the concept of ＇reduced frequency＇, a measure which can quantify natural frequencies of each pair of oscillators. Then we introduce an evolving network whose linking rules are controlled by its own dynamical property. The simulation results indicate that when the linking probability positively correlates with the reduced frequency, the network undergoes a first-order phase transition. Meanwhile, we discuss the circumstance under which an explosive synchronization can be ignited. The numerical results show that the peculiar butterfly shape correlation between frequencies and degrees of the nodes contributes to an explosive synchronization transition.展开更多
A modified energy-balance equation accounting for P-delta effects and hysteretic behavior of reinforced concrete members is derived. Reduced hysteretic properties of structural components due to combined stiffness and...A modified energy-balance equation accounting for P-delta effects and hysteretic behavior of reinforced concrete members is derived. Reduced hysteretic properties of structural components due to combined stiffness and strength degradation and pinching effects, and hysteretic damping are taken into account in a simple manner by utilizing plastic energy and seismic input energy modification factors. Having a pre-selected yield mechanism, energy balance of structure in inelastic range is considered. P-delta effects are included in derived equation by adding the external work of gravity loads to the work of equivalent inertia forces and equating the total external work to the modified plastic energy. Earthquake energy input to multi degree of freedom（MDOF） system is approximated by using the modal energy-decomposition. Energybased base shear coefficients are verified by means of both pushover analysis and nonlinear time history（NLTH） analysis of several RC frames having different number of stories. NLTH analyses of frames are performed by using the time histories of ten scaled ground motions compatible with elastic design acceleration spectrum and fulfilling duration/amplitude related requirements of Turkish Seismic Design Code. The observed correlation between energy-based base shear force coefficients and the average base shear force coefficients of NLTH analyses provides a reasonable confidence in estimation of nonlinear base shear force capacity of frames by using the derived equation.展开更多
Green leaf volatiles（GLVs） emitted by plants after stress or damage induction are a major part of biogenic volatile organic compounds（BVOCs）. Proton transfer reaction time-of-flight mass spectrometry（PTR-TOF-MS）...Green leaf volatiles（GLVs） emitted by plants after stress or damage induction are a major part of biogenic volatile organic compounds（BVOCs）. Proton transfer reaction time-of-flight mass spectrometry（PTR-TOF-MS） is a high-resolution and sensitive technique for in situ GLV analyses, while its performance is dramatically influenced by humidity, electric field,etc. In this study the influence of gas humidity and the effect of reduced field（E/N） were examined in addition to measuring calibration curves for the GLVs. Calibration curves measured for seven of the GLVs in dry air were linear, with sensitivities ranging from 5 to10 ncps/ppbv（normalized counts per second/parts per billion by volume）. The sensitivities for most GLV analyses were found to increase by between 20% and 35% when the humidity of the sample gas was raised from 0% to 70% relative humidity（RH） at 21°C, with the exception of（E）-2-hexenol. Product ion branching ratios were also affected by humidity,with the relative abundance of the protonated molecular ions and higher mass fragment ions increasing with humidity. The effect of reduced field（E/N） on the fragmentation of GLVs was examined in the drift tube of the PTR-TOF-MS. The structurally similar GLVs are acutely susceptible to fragmentation following ionization and the fragmentation patterns are highly dependent on E/N. Overall the measured fragmentation patterns contain sufficient information to permit at least partial separation and identification of the isomeric GLVs by looking at differences in their fragmentation patterns at high and low E/N.展开更多
Chinese materia medica(CMM) compatibility is one core content in the theory of Traditional Chinese Medicine(TCM), and elaborating the scientific connotation of CMM compatibility is of great significance to promote the...Chinese materia medica(CMM) compatibility is one core content in the theory of Traditional Chinese Medicine(TCM), and elaborating the scientific connotation of CMM compatibility is of great significance to promote the modernization of TCM. Self-assembly is the combination of active ingredients into aggregates through noncovalent bonds, such as hydrogen bonding, electrostatic interactions, ionic interactions, and hydrophobic interactions. The complex properties and special structures of CMM components create the basis for selfassembly. The self-assembled materials formed after CMM compatibility is an important part of the material basis for the efficacy of TCM, which can help explain the scientific connotations of CMM compatibility. This review summarizes the self-assembly phenomenon from the perspective of drug pair combinations in recent decades and explains the scientific connotation of CMM compatibility about the material basis, pharmacodynamic changes, and mechanism of action, providing new ideas and methods for the study of TCM.展开更多
Metal-organic framework(MOF)membranes with an ultra-small pore size(<4Å)have shown great prospects in the highly selective separation of small gas molecules such as hydrogen,but their narrow channels may resul...Metal-organic framework(MOF)membranes with an ultra-small pore size(<4Å)have shown great prospects in the highly selective separation of small gas molecules such as hydrogen,but their narrow channels may result in a low gas permeance.To improve the gas permeance of ultra-microporous MOF membranes,a stable covalent organic framework(COF)with large and uniform pores is doped to construct a binary COF/MOF all-nanoporous composite(ANC)membrane,equivalent to reducing the effective membrane thickness but avoiding the challenging ultra-thin membrane preparation.The COF synthesized by ball milling is combined with a metal gel to form a precursor membrane,which was then transformed to a COF/MOF ANC membrane by treatment with the MOF ligand vapor.A very small amount of solvent has been applied,offering an environmentally-friendly preparation process.Compared with the pristine MOF membrane,the COF/MOF ANC membranes possess a highly improved gas permeance from 22 GPU to 551 GPU with a slight sacrifice of selectivity;this introduces a new strategy to optimize the separation performance of MOF membranes.展开更多
In this paper we consider the effective reducibility of the following linear differential equation: , where A is a constant matrix, Q(t,?) is quasiperiodic in t, and ? is a small perturbation parameter. We prove that...In this paper we consider the effective reducibility of the following linear differential equation: , where A is a constant matrix, Q(t,?) is quasiperiodic in t, and ? is a small perturbation parameter. We prove that if the eigenvalues of A and the basic frequencies of Q satisfy some non-resonant conditions, the linear differential equation can be reduced to , where R* is exponentially small in ?.展开更多
The study of the lead chalcogenides system has been extended throughout the history of thermoelectrics due to their extraordinary physical and chemical properties.Compared with PbTe,PbSe has been drawing increased att...The study of the lead chalcogenides system has been extended throughout the history of thermoelectrics due to their extraordinary physical and chemical properties.Compared with PbTe,PbSe has been drawing increased attention because it combines several attractive features,such as higher melting point,lower cost,and higher operation temperatures.The all-scale hierarchical structures were successfully applied to p-type PbSe systems,and a fascinating ZT value was achieved by effectively reducing the lattice thermal conductivity,which could be attributed to phonon scattering with a spectrum of wavelengths.展开更多
基金Supported by the Open Fund from Guangxi Colleges and Universities Key Laboratory of Complex System Optimization and Big Data Processing under Grant No 2015CSOBDP0101the National Natural Science Foundation of China under Grant No11162019
文摘Synchronization of networked phase oscillators depends essentially on the correlation between the topological structure of the graph and the dynamical property of the elements. We propose the concept of ＇reduced frequency＇, a measure which can quantify natural frequencies of each pair of oscillators. Then we introduce an evolving network whose linking rules are controlled by its own dynamical property. The simulation results indicate that when the linking probability positively correlates with the reduced frequency, the network undergoes a first-order phase transition. Meanwhile, we discuss the circumstance under which an explosive synchronization can be ignited. The numerical results show that the peculiar butterfly shape correlation between frequencies and degrees of the nodes contributes to an explosive synchronization transition.
文摘A modified energy-balance equation accounting for P-delta effects and hysteretic behavior of reinforced concrete members is derived. Reduced hysteretic properties of structural components due to combined stiffness and strength degradation and pinching effects, and hysteretic damping are taken into account in a simple manner by utilizing plastic energy and seismic input energy modification factors. Having a pre-selected yield mechanism, energy balance of structure in inelastic range is considered. P-delta effects are included in derived equation by adding the external work of gravity loads to the work of equivalent inertia forces and equating the total external work to the modified plastic energy. Earthquake energy input to multi degree of freedom（MDOF） system is approximated by using the modal energy-decomposition. Energybased base shear coefficients are verified by means of both pushover analysis and nonlinear time history（NLTH） analysis of several RC frames having different number of stories. NLTH analyses of frames are performed by using the time histories of ten scaled ground motions compatible with elastic design acceleration spectrum and fulfilling duration/amplitude related requirements of Turkish Seismic Design Code. The observed correlation between energy-based base shear force coefficients and the average base shear force coefficients of NLTH analyses provides a reasonable confidence in estimation of nonlinear base shear force capacity of frames by using the derived equation.
基金supported by the Chinese National Natural Science Foundation (41175110)the funding for the Distinguished Professor of Jiangsu Province
文摘Green leaf volatiles（GLVs） emitted by plants after stress or damage induction are a major part of biogenic volatile organic compounds（BVOCs）. Proton transfer reaction time-of-flight mass spectrometry（PTR-TOF-MS） is a high-resolution and sensitive technique for in situ GLV analyses, while its performance is dramatically influenced by humidity, electric field,etc. In this study the influence of gas humidity and the effect of reduced field（E/N） were examined in addition to measuring calibration curves for the GLVs. Calibration curves measured for seven of the GLVs in dry air were linear, with sensitivities ranging from 5 to10 ncps/ppbv（normalized counts per second/parts per billion by volume）. The sensitivities for most GLV analyses were found to increase by between 20% and 35% when the humidity of the sample gas was raised from 0% to 70% relative humidity（RH） at 21°C, with the exception of（E）-2-hexenol. Product ion branching ratios were also affected by humidity,with the relative abundance of the protonated molecular ions and higher mass fragment ions increasing with humidity. The effect of reduced field（E/N） on the fragmentation of GLVs was examined in the drift tube of the PTR-TOF-MS. The structurally similar GLVs are acutely susceptible to fragmentation following ionization and the fragmentation patterns are highly dependent on E/N. Overall the measured fragmentation patterns contain sufficient information to permit at least partial separation and identification of the isomeric GLVs by looking at differences in their fragmentation patterns at high and low E/N.
基金the Science and Technology Innovation Project of the China Academy of Chinese Medical Sciences:Establishment of Research Methods for Protein Supramolecular Components in Chinese Medicine decoctionC12021A00108Independent Selection Project of Institute of Basic Theory of Chinese Medicine,China Academy of Chinese Medical Sciences:Exploration and Case Study of the Research Model of"Theory and Experiment"on the Compatibility of Traditional Chinese Medicine,YZ-202109。
文摘Chinese materia medica(CMM) compatibility is one core content in the theory of Traditional Chinese Medicine(TCM), and elaborating the scientific connotation of CMM compatibility is of great significance to promote the modernization of TCM. Self-assembly is the combination of active ingredients into aggregates through noncovalent bonds, such as hydrogen bonding, electrostatic interactions, ionic interactions, and hydrophobic interactions. The complex properties and special structures of CMM components create the basis for selfassembly. The self-assembled materials formed after CMM compatibility is an important part of the material basis for the efficacy of TCM, which can help explain the scientific connotations of CMM compatibility. This review summarizes the self-assembly phenomenon from the perspective of drug pair combinations in recent decades and explains the scientific connotation of CMM compatibility about the material basis, pharmacodynamic changes, and mechanism of action, providing new ideas and methods for the study of TCM.
基金supported by the National Natural Science Foundation of China(Grants No.21501198,21601205 and 21771193)the Taishan Scholar Foundation(ts201511019)+3 种基金the Fundamental Research Funds for the Central Universities(20CX05010A)the PetroChina Innovation Foundation(2019D-5007-0411)the Key Research and Development Projects of Shandong Province(2019JZZY010331)the Shandong Province Natural Science Foundation(ZR2020MB017).
文摘Metal-organic framework(MOF)membranes with an ultra-small pore size(<4Å)have shown great prospects in the highly selective separation of small gas molecules such as hydrogen,but their narrow channels may result in a low gas permeance.To improve the gas permeance of ultra-microporous MOF membranes,a stable covalent organic framework(COF)with large and uniform pores is doped to construct a binary COF/MOF all-nanoporous composite(ANC)membrane,equivalent to reducing the effective membrane thickness but avoiding the challenging ultra-thin membrane preparation.The COF synthesized by ball milling is combined with a metal gel to form a precursor membrane,which was then transformed to a COF/MOF ANC membrane by treatment with the MOF ligand vapor.A very small amount of solvent has been applied,offering an environmentally-friendly preparation process.Compared with the pristine MOF membrane,the COF/MOF ANC membranes possess a highly improved gas permeance from 22 GPU to 551 GPU with a slight sacrifice of selectivity;this introduces a new strategy to optimize the separation performance of MOF membranes.
文摘In this paper we consider the effective reducibility of the following linear differential equation: , where A is a constant matrix, Q(t,?) is quasiperiodic in t, and ? is a small perturbation parameter. We prove that if the eigenvalues of A and the basic frequencies of Q satisfy some non-resonant conditions, the linear differential equation can be reduced to , where R* is exponentially small in ?.
基金supported by the National Natural Science Foundation of China under Grant No.51571007,and the Recruitment Program for Young Professionals and the Fundamental Research Funds for the Central Universities.
文摘The study of the lead chalcogenides system has been extended throughout the history of thermoelectrics due to their extraordinary physical and chemical properties.Compared with PbTe,PbSe has been drawing increased attention because it combines several attractive features,such as higher melting point,lower cost,and higher operation temperatures.The all-scale hierarchical structures were successfully applied to p-type PbSe systems,and a fascinating ZT value was achieved by effectively reducing the lattice thermal conductivity,which could be attributed to phonon scattering with a spectrum of wavelengths.
