Introduction The molecular dynamics simulation technique has recently proved to be a suitable alternative approachfor simulation of vibrational spectroscopy. In this study, molecular dynamics was utilized to understan...Introduction The molecular dynamics simulation technique has recently proved to be a suitable alternative approachfor simulation of vibrational spectroscopy. In this study, molecular dynamics was utilized to understandlow frequency vibrations in highly ordered poly(ρ-phenylene terephthalmide) (PPTA). A key structuralfeature of this polymer is the presence of hydrogen bonds. There is little question that this strong localized展开更多
The groundwater level of 39 observation wells including 35 unconfined wells and 4 confined wells from 2004 to 2006 in North China Plain(NCP) was monitored using automatic groundwater monitoring data loggers KADEC-MIZU...The groundwater level of 39 observation wells including 35 unconfined wells and 4 confined wells from 2004 to 2006 in North China Plain(NCP) was monitored using automatic groundwater monitoring data loggers KADEC-MIZU II of Japan.The automatic groundwater sensors were installed for the corporation project between China and Japan.Combined with the monitoring results from 2004 to 2006 with the major factors affecting the dynamic patterns of groundwater, such as topography and landform, depth of groundwater level, exploitation or discharge extent, rivers and lakes, the dynamic regions of NCP groundwater were gotten.According to the dynamic features of groundwater in NCP, six dynamic patterns of groundwater level were identified, including discharge pattern in the piedmont plain, lateral recharge-runoff-discharge pattern in the piedmont plain, recharge-discharge pattern in the central channel zone, precipitation infiltration-evaporation pattern in the shallow groundwater region of the central plain, lateral recharge-evaporation pattern in the recharge-affected area along the Yellow River and infiltration-discharge-evaporation pattern in the littoral plain.Based on this, the groundwater fluctuation features of various dynamic patterns were interpreted and the influencing factors of different dynamic patterns were compared.展开更多
Detailed parametric study of three-dimensional gas-particle multiphase flow characteristics in U-beam tube bundle inertial separators was conducted by numerical simulation. The carrier phase was treated in the Euleria...Detailed parametric study of three-dimensional gas-particle multiphase flow characteristics in U-beam tube bundle inertial separators was conducted by numerical simulation. The carrier phase was treated in the Eulerian frame, the particles were tracked in the Lagrangian frame, and particle-wall collision was considered. Simulation carried out at different inflow rate and mass loading ratios revealed the pressure losses in the separators, velocity field of the gas phase, and the trajectories of particles. The study results revealed the multiphase flow-dynamic features of the separators, and the relationship between separator pressure losses and different inlet velocity. The numerical simulation can provide basis both for optimal design of impacting-inertial separator used in circulating fluidized bed boiler; and for study of gas-particle multiphase circumfluence flow.展开更多
Stability is the key issue for kinetic-energy supercavitating projectiles.Our previous work established a six degrees of freedom(DOF)dynamic model for supercavitating projectiles.However,the projectile’s structure di...Stability is the key issue for kinetic-energy supercavitating projectiles.Our previous work established a six degrees of freedom(DOF)dynamic model for supercavitating projectiles.However,the projectile’s structure did not meet our current design specifications(its sailing distance could reach 100 m at an initial speed of 500 m/s).The emphasis of this study lies in optimizing the projectile’s configuration.Therefore,a program was developed to optimize the projectile’s structure to achieve an optimal design or the largest sailing distance.The program is a working optimal method based on the genetic algorithm(GA).Additionally,the convergence standard and population producing strategy were improved,which greatly elevated the calculation speed and precision.To meet design specifications,the improved GA was combined with the 6DOF model,which establishes a dynamic optimization problem.The new projectile’s structure was obtained by solving this problem.Then,the new structures’dynamic features were compared with the ideals proposed in this paper.The criterion of stability,which is called weakened self-stability,was redefined based on the results.The weakened self-stability is the optimal stability for an actual kinetic projectile motion,and it is instructive for the design of supercavitating projectiles in the future.展开更多
Flavonoids in plants is very important in its ecological role and economicvalue. The dynamic features of flavonoids content in different organs of larch (Larix gmelinii) atdifferent light and temperature conditions we...Flavonoids in plants is very important in its ecological role and economicvalue. The dynamic features of flavonoids content in different organs of larch (Larix gmelinii) atdifferent light and temperature conditions were investigated in this study. Results showed that theorder of flavonoids content in different organs from high to low was 7.78% (stem bark) > 2.79%(leaves) > 1.72% (branches) > 1.19% (stem xylem)and different organs had a great seasonal variationin flavonoids content, but the change of flavonoids content at different temperature was not obviousin different organs., The content of flavonoids in barck had, a positive correlation withtemperature (R^2=0.75), but that in other organs had slight variation with the change oftemperatures. For all the tested organs, the flavonoids content in summer and autumn wasapproximately 3-4 times higher than in spring and winter. This is attributed to the great stressfrom environmental physical variables such as UV radiation, high temperature that induce theaccumulation of flavonoids. The flavonoid content of sun leaves was evidently higher than that ofshade leaves, and leaves at upper part of canopy had a higher flavonoids content compared with thatat other parts. This result indicates that sun radiation could improve flavonoids production inleaves (R^2=0.76). The flavonoids may actively evolve in plant defenses to environmental stress,protecting larch from the damage of high temperature and radiation, and its main function isdifferent in different organs.展开更多
The present paper deals with the Sharma-Tasso-Olver-Burgers equation(STOBE)and its conservation laws and kink solitons.More precisely,the formal Lagrangian,Lie symmetries,and adjoint equations of the STOBE are firstly...The present paper deals with the Sharma-Tasso-Olver-Burgers equation(STOBE)and its conservation laws and kink solitons.More precisely,the formal Lagrangian,Lie symmetries,and adjoint equations of the STOBE are firstly constructed to retrieve its conservation laws.Kink solitons of the STOBE are then extracted through adopting a series of newly well-designed approaches such as Kudryashov and exponential methods.Diverse graphs in 2 and 3D postures are formally portrayed to reveal the dynamical features of kink solitons.According to the authors’knowledge,the outcomes of the current investigation are new and have been listed for the first time.展开更多
The topic recognition for dynamic topic number can realize the dynamic update of super parameters,and obtain the probability distribution of dynamic topics in time dimension,which helps to clear the understanding and ...The topic recognition for dynamic topic number can realize the dynamic update of super parameters,and obtain the probability distribution of dynamic topics in time dimension,which helps to clear the understanding and tracking of convection text data.However,the current topic recognition model tends to be based on a fixed number of topics K and lacks multi-granularity analysis of subject knowledge.Therefore,it is impossible to deeply perceive the dynamic change of the topic in the time series.By introducing a novel approach on the basis of Infinite Latent Dirichlet allocation model,a topic feature lattice under the dynamic topic number is constructed.In the model,documents,topics and vocabularies are jointly modeled to generate two probability distribution matrices:Documentstopics and topic-feature words.Afterwards,the association intensity is computed between the topic and its feature vocabulary to establish the topic formal context matrix.Finally,the topic feature is induced according to the formal concept analysis(FCA)theory.The topic feature lattice under dynamic topic number(TFL DTN)model is validated on the real dataset by comparing with the mainstream methods.Experiments show that this model is more in line with actual needs,and achieves better results in semi-automatic modeling of topic visualization analysis.展开更多
Investigated in the present paper is a fifth-order nonlinear evolution(FONLE)equation,known as a nonlinear water wave(NLWW)equation,with applications in the applied sciences.More precisely,a traveling wave hypothesis ...Investigated in the present paper is a fifth-order nonlinear evolution(FONLE)equation,known as a nonlinear water wave(NLWW)equation,with applications in the applied sciences.More precisely,a traveling wave hypothesis is firstly applied that reduces the FONLE equation to a 1D domain.The Kudryashov methods(KMs)are then adopted as leading techniques to construct specific wave structures of the governing model which are classified as W-shaped and other solitons.In the end,the effect of changing the coefficients of nonlinear terms on the dynamical features of W-shaped and other solitons is investigated in detail for diverse groups of the involved parameters.展开更多
文摘Introduction The molecular dynamics simulation technique has recently proved to be a suitable alternative approachfor simulation of vibrational spectroscopy. In this study, molecular dynamics was utilized to understandlow frequency vibrations in highly ordered poly(ρ-phenylene terephthalmide) (PPTA). A key structuralfeature of this polymer is the presence of hydrogen bonds. There is little question that this strong localized
基金National Natural Sciences Foundation of China,No.40671034 No.40830636
文摘The groundwater level of 39 observation wells including 35 unconfined wells and 4 confined wells from 2004 to 2006 in North China Plain(NCP) was monitored using automatic groundwater monitoring data loggers KADEC-MIZU II of Japan.The automatic groundwater sensors were installed for the corporation project between China and Japan.Combined with the monitoring results from 2004 to 2006 with the major factors affecting the dynamic patterns of groundwater, such as topography and landform, depth of groundwater level, exploitation or discharge extent, rivers and lakes, the dynamic regions of NCP groundwater were gotten.According to the dynamic features of groundwater in NCP, six dynamic patterns of groundwater level were identified, including discharge pattern in the piedmont plain, lateral recharge-runoff-discharge pattern in the piedmont plain, recharge-discharge pattern in the central channel zone, precipitation infiltration-evaporation pattern in the shallow groundwater region of the central plain, lateral recharge-evaporation pattern in the recharge-affected area along the Yellow River and infiltration-discharge-evaporation pattern in the littoral plain.Based on this, the groundwater fluctuation features of various dynamic patterns were interpreted and the influencing factors of different dynamic patterns were compared.
文摘Detailed parametric study of three-dimensional gas-particle multiphase flow characteristics in U-beam tube bundle inertial separators was conducted by numerical simulation. The carrier phase was treated in the Eulerian frame, the particles were tracked in the Lagrangian frame, and particle-wall collision was considered. Simulation carried out at different inflow rate and mass loading ratios revealed the pressure losses in the separators, velocity field of the gas phase, and the trajectories of particles. The study results revealed the multiphase flow-dynamic features of the separators, and the relationship between separator pressure losses and different inlet velocity. The numerical simulation can provide basis both for optimal design of impacting-inertial separator used in circulating fluidized bed boiler; and for study of gas-particle multiphase circumfluence flow.
基金Supported by the National Natural Science Foundation of China under Grant No.62101590.
文摘Stability is the key issue for kinetic-energy supercavitating projectiles.Our previous work established a six degrees of freedom(DOF)dynamic model for supercavitating projectiles.However,the projectile’s structure did not meet our current design specifications(its sailing distance could reach 100 m at an initial speed of 500 m/s).The emphasis of this study lies in optimizing the projectile’s configuration.Therefore,a program was developed to optimize the projectile’s structure to achieve an optimal design or the largest sailing distance.The program is a working optimal method based on the genetic algorithm(GA).Additionally,the convergence standard and population producing strategy were improved,which greatly elevated the calculation speed and precision.To meet design specifications,the improved GA was combined with the 6DOF model,which establishes a dynamic optimization problem.The new projectile’s structure was obtained by solving this problem.Then,the new structures’dynamic features were compared with the ideals proposed in this paper.The criterion of stability,which is called weakened self-stability,was redefined based on the results.The weakened self-stability is the optimal stability for an actual kinetic projectile motion,and it is instructive for the design of supercavitating projectiles in the future.
基金This paper is supported by the National Natural Science Foundation of China (30300271) and the Key Project of Chinese Ministry of Education (104191).
文摘Flavonoids in plants is very important in its ecological role and economicvalue. The dynamic features of flavonoids content in different organs of larch (Larix gmelinii) atdifferent light and temperature conditions were investigated in this study. Results showed that theorder of flavonoids content in different organs from high to low was 7.78% (stem bark) > 2.79%(leaves) > 1.72% (branches) > 1.19% (stem xylem)and different organs had a great seasonal variationin flavonoids content, but the change of flavonoids content at different temperature was not obviousin different organs., The content of flavonoids in barck had, a positive correlation withtemperature (R^2=0.75), but that in other organs had slight variation with the change oftemperatures. For all the tested organs, the flavonoids content in summer and autumn wasapproximately 3-4 times higher than in spring and winter. This is attributed to the great stressfrom environmental physical variables such as UV radiation, high temperature that induce theaccumulation of flavonoids. The flavonoid content of sun leaves was evidently higher than that ofshade leaves, and leaves at upper part of canopy had a higher flavonoids content compared with thatat other parts. This result indicates that sun radiation could improve flavonoids production inleaves (R^2=0.76). The flavonoids may actively evolve in plant defenses to environmental stress,protecting larch from the damage of high temperature and radiation, and its main function isdifferent in different organs.
文摘The present paper deals with the Sharma-Tasso-Olver-Burgers equation(STOBE)and its conservation laws and kink solitons.More precisely,the formal Lagrangian,Lie symmetries,and adjoint equations of the STOBE are firstly constructed to retrieve its conservation laws.Kink solitons of the STOBE are then extracted through adopting a series of newly well-designed approaches such as Kudryashov and exponential methods.Diverse graphs in 2 and 3D postures are formally portrayed to reveal the dynamical features of kink solitons.According to the authors’knowledge,the outcomes of the current investigation are new and have been listed for the first time.
基金the Key Projects of Social Sciences of Anhui Provincial Department of Education(SK2018A1064,SK2018A1072)the Natural Scientific Project of Anhui Provincial Department of Education(KJ2019A0371)Innovation Team of Health Information Management and Application Research(BYKC201913),BBMC。
文摘The topic recognition for dynamic topic number can realize the dynamic update of super parameters,and obtain the probability distribution of dynamic topics in time dimension,which helps to clear the understanding and tracking of convection text data.However,the current topic recognition model tends to be based on a fixed number of topics K and lacks multi-granularity analysis of subject knowledge.Therefore,it is impossible to deeply perceive the dynamic change of the topic in the time series.By introducing a novel approach on the basis of Infinite Latent Dirichlet allocation model,a topic feature lattice under the dynamic topic number is constructed.In the model,documents,topics and vocabularies are jointly modeled to generate two probability distribution matrices:Documentstopics and topic-feature words.Afterwards,the association intensity is computed between the topic and its feature vocabulary to establish the topic formal context matrix.Finally,the topic feature is induced according to the formal concept analysis(FCA)theory.The topic feature lattice under dynamic topic number(TFL DTN)model is validated on the real dataset by comparing with the mainstream methods.Experiments show that this model is more in line with actual needs,and achieves better results in semi-automatic modeling of topic visualization analysis.
文摘Investigated in the present paper is a fifth-order nonlinear evolution(FONLE)equation,known as a nonlinear water wave(NLWW)equation,with applications in the applied sciences.More precisely,a traveling wave hypothesis is firstly applied that reduces the FONLE equation to a 1D domain.The Kudryashov methods(KMs)are then adopted as leading techniques to construct specific wave structures of the governing model which are classified as W-shaped and other solitons.In the end,the effect of changing the coefficients of nonlinear terms on the dynamical features of W-shaped and other solitons is investigated in detail for diverse groups of the involved parameters.
