The struetural effect of the conjugative system(C)with carbonyl-imino bridges has been studied.The results show that:In the conjugated system(C),there is no electronic absorption peak attributable to the whole system,...The struetural effect of the conjugative system(C)with carbonyl-imino bridges has been studied.The results show that:In the conjugated system(C),there is no electronic absorption peak attributable to the whole system,but there are three π-π* bands each nt which displays chacactecistics of its own independently.These indicate that the two bridges-carbonyl-and-imino-can block the tlanSmlSSion of the conjngative polarization of the whole system,so as to form three segments,this is verified by means of chemical synthesis and degradation.展开更多
1 Introduction In recent years porous carbons have been widely used in many fields such as energy storage(Mc Creery,2008;Liu et al,2009;Ho et al,2014;Yang et al,2015),adsorption,wastewater treatment,air purification
A parallel-coupled double quantum dot (PCDQD) system with two multi-quantum dot chains is designed. Conductance versus Fermi energy level is investigated utilizing the non-equilibrium Green's function approach. If ...A parallel-coupled double quantum dot (PCDQD) system with two multi-quantum dot chains is designed. Conductance versus Fermi energy level is investigated utilizing the non-equilibrium Green's function approach. If two quantum dots are added on each side of the PCDQD system, additional Breit Wigner and Fano resonances occur in the conductance spectra. If quantum dots are added on one side of the system, small Fano resonances can be observed in the conductance spectra. Adjusting the number of side-coupled quantum dots, the anti-resonance bands emerge at different positions, which makes the system applicable as a quantum switching device. Moreover, the I-V characteristic curve presents the step characteristic and the width of the step decreases with increasing the number of side-coupled quantum dots.展开更多
Many factors can induce rock burst. Shock energy and shock distance are two key factors affecting rock burst. The 32101 roadway of the Xingcun coal mine, which has a tendency for rock burst, was used as an example. Th...Many factors can induce rock burst. Shock energy and shock distance are two key factors affecting rock burst. The 32101 roadway of the Xingcun coal mine, which has a tendency for rock burst, was used as an example. The dynamic module of Itasca’s FLAC (Fast Lagrangian Analysis of Continua) 2D explicit finite-difference software was used to simulate the roadway’s destruction. The vibration velocity and displacements of the rock surrounding the roadway were modeled for different shock energies and hypocenter distances. The simulation results indicate that the vibration velocity and displacement of rock surrounding the roadway have a quadratic relationship to the shock energy and a power law relationship to the distance of the hypocenter from the roadway. A dynamic view of the process was obtained from a series of "snap-shots" collected at 100 different time steps. This shows an isolating "river" is first formed at the hypocenter. The region above the "river" is a low stress zone while below the "river" a high stress zone exists. This high stress zone surrounds the ribs of the roadway in a "double ear" pattern. Continuous and repeated action of the high stress in the "double ear" shaped zone destroys the roadway.展开更多
The flow past a primary cylinder with one tandem control rod and one staggered control rod is simulated in this paper through solving the Navier-Stokes equations. Two examples are simulated to validate the model, and ...The flow past a primary cylinder with one tandem control rod and one staggered control rod is simulated in this paper through solving the Navier-Stokes equations. Two examples are simulated to validate the model, and the results matched well with those of previous researches. The Reynolds number based on the diameter of the primary cylinder is 500. The diameter ratio between the control rod and the primary cylinder (d/D) is 0.25. It was found that the effect of the combination of one upstream tandem control rod and one staggered control rod on the hydrodynamics of the primary cylinder is a linear superposition of the effect of a corresponding single control rod, and the effect of the upstream tandem control rod is dominant at larger spacing ratios such as G/D=2. For the combination of a downstream tandem control rod and a staggered control rod, the effect of the control rods is different from that of the corresponding single control rod in the region of 0.2〈G/D〈0.5 & 30°〈a〈120° and 0.9〈G/D〈1.4 & 30°〈a〈50°, where the additional effect is obvious. In this case, the effect of the downstream tandem control rod is dominant at small spacing ratios (such as G/D=0.1). At moderate spacing ratios such as G/D=0.4, the effects of the tandem control rod and the staggered control rod are comparable in both cases.展开更多
Synchronization of quantum mechanics with relativity has been considered differently from the present quantum gravity models. It is originated from the roots of philosophy of physics and the basic concepts of relativi...Synchronization of quantum mechanics with relativity has been considered differently from the present quantum gravity models. It is originated from the roots of philosophy of physics and the basic concepts of relativity & quantum mechanics. It emphasizes the fact that two conscious observers are necessary to experience one conscious moment. Various concepts of consciousness have been discussed and emphasized the necessity for the introduction of a new model of quantum consciousness. A quantum coordinate system has been introduced to explain the present understanding of the phenomena “observation” and “reality”. It has been elaborated that the observation defined by physics is confined to Lorentz space time coordinate system, Minkowski coordinate system and general relativity. But phenomena of observation cannot be completed without considering one more hidden transformation explaining quantum coordinate system which transforms the quantum states into relativistic coordinate system as an interaction between two conscious observers explained by an interactive mechanism of quantum states. A flow chart has been illustrated by a mechanism giving rise to conscious moment and proposed a new model of consciousness. It emphasizes on the fact that “reality” is different from “observation” defined by physics. It affects the relativistic factor of special relativity and suggests a modification for it. If this modified relativistic factor is proved experimentally, the results establish consciousness’s mechanism and a remarkable breakthrough in physics of consciousness studies.展开更多
A classical ensemble method is used to investigate nonsequential double ionization(NSDI) of Ar atoms irradiated by linearly polarized few-cycle laser pulses. The correlated-electron momentum distribution(CMD) exhi...A classical ensemble method is used to investigate nonsequential double ionization(NSDI) of Ar atoms irradiated by linearly polarized few-cycle laser pulses. The correlated-electron momentum distribution(CMD) exhibits a strong dependence on the carrier-envelope phase(CEP). When the pulse duration is four cycles, the CMD shows a cross-like structure, which is consistent with experimental results. The CEP dependence is more notable when the laser pulse duration is decreased to two cycles and a special L-shaped structure appears in CMD. Recollision time of returning electrons greatly depends on CEP, which plays a significant role in accounting for the appearance of this structure.展开更多
The effects of doubled carbon dioxide on rainfall responses to radiative processes of water clouds are investigated in this study.Two groups of two-dimensional cloud-resolving model sensitivity experiments with regard...The effects of doubled carbon dioxide on rainfall responses to radiative processes of water clouds are investigated in this study.Two groups of two-dimensional cloud-resolving model sensitivity experiments with regard to pre-summer heavy rainfall around the summer solstice and tropical rainfall around the winter solstice are conducted and their five-day averages over the model domain are analyzed.In the presence of radiative effects of ice clouds,doubled carbon dioxide changes pre-summer rainfall from the decrease associated with the enhanced atmospheric cooling to the increase associated with the enhanced infrared cooling as a result of the exclusion of radiative effects of water clouds.Doubled carbon dioxide leads to the reduction in tropical rainfall,caused by the removal of radiative effects of water clouds through the suppressed infrared cooling.In the absence of radiative effects of ice clouds,doubled carbon dioxide changes pre-summer rainfall from the increase associated with the strengthened atmospheric warming to the decrease associated with the weakened release of latent heat caused by the elimination of radiative effects of water clouds.The exclusion of radiative effects of water clouds increases tropical rainfall through the strengthened infrared cooling,which is insensitive to the change in carbon dioxide.展开更多
Using de-ionized ultra-filtered water (DIUFW) as the working fluid, the effects of viscous dissipation in micro-tubes with inner diameters of 19.9μm and 44.2μm, respectively, have been studied by experiments, the th...Using de-ionized ultra-filtered water (DIUFW) as the working fluid, the effects of viscous dissipation in micro-tubes with inner diameters of 19.9μm and 44.2μm, respectively, have been studied by experiments, the theoretical analysis and the numerical simulation at laminar state. Based on thermal imaging technology of micro-area, the temperature rise resulted from the viscous dissipation in microtube is measured by employing IR camera with a specially magnifying lens at different Reynolds numbers. A 2-D model adapted to microtube is presented to simulate the viscous dissipation characteristic considering electric double layer effect (EDL). The investigation shows the calculating results are in rough agreement with the experimental data if removing the experimental uncertainties. Based on the experimental and the numerical simulation results, a viscous dissipation number which can describe the law of the viscous heating in microtube is summed up and it explains the abnormity of the flow resistance in microtubes.展开更多
Poly(methyl methacrylate)(PMMA)/polystyrene(PS)/carbon black(CB)and poly(ethyl methacrylate)(PEMA)/PS/CB ternary composite films were obtained using solution casting technique to investigate double percolation effect....Poly(methyl methacrylate)(PMMA)/polystyrene(PS)/carbon black(CB)and poly(ethyl methacrylate)(PEMA)/PS/CB ternary composite films were obtained using solution casting technique to investigate double percolation effect.In both PMMA/PS/CB and PEMA/PS/CB ternary composite films,the CB particles prefer to locate into PS phase based on the results of calculating wetting coefficient,which is also confirmed by SEM images.The conductivity of the films was investigated,and the percolation threshold(¢c)of both ternary composite films with different polymer blend ratios was determined by fitting the McLachlan GEM equation.Conductivity of PMMA/PS/CB ternary composite films showed a typical double percolation effect.However,due to the double emulsion structure of PEMA/PS polymer blends,the PEMA/PS/CB ternary composite films(PEMA/PS=50/50)showed a higher¢c,even CB only located in PS phase,which conflicts with the double percolation effect.A schematic diagram combined with SEM images was proposed to explain this phenomenon.展开更多
Influences of light irradiation on the negative resistance turn-around characteristics of static induction photosensitive thyristor (SIPTH) have been experimentally and theoretically studied. As the gate current of ...Influences of light irradiation on the negative resistance turn-around characteristics of static induction photosensitive thyristor (SIPTH) have been experimentally and theoretically studied. As the gate current of SIPTH is increased by the light irradiation, the potential barrier in the channel is reduced due to the increase in voltage drop across the gate series resistance. Therefore, SIPTH can be quickly switched from the blocking state to the conducting state by relatively low anode voltage. The optimal matching relation for controlling anode conducting voltage of SIPTH by light irradiation has also been represented.展开更多
文摘The struetural effect of the conjugative system(C)with carbonyl-imino bridges has been studied.The results show that:In the conjugated system(C),there is no electronic absorption peak attributable to the whole system,but there are three π-π* bands each nt which displays chacactecistics of its own independently.These indicate that the two bridges-carbonyl-and-imino-can block the tlanSmlSSion of the conjngative polarization of the whole system,so as to form three segments,this is verified by means of chemical synthesis and degradation.
基金financial support from the National Natural Science Foundation of China (51274015)National Program on Key Basic Research Project (973 Program) (2014CB846000)Test Fund of Peking University
文摘1 Introduction In recent years porous carbons have been widely used in many fields such as energy storage(Mc Creery,2008;Liu et al,2009;Ho et al,2014;Yang et al,2015),adsorption,wastewater treatment,air purification
基金Supported by the National Natural Science Foundation of China under Grant Nos 11447132 and 11504042the Chongqing Science and Technology Commission Project under Grant Nos cstc2014jcyj A00032 and cstc2016jcyj A1158the Scientific Research Project for Advanced Talents of Yangtze Normal University under Grant No 2017KYQD09
文摘A parallel-coupled double quantum dot (PCDQD) system with two multi-quantum dot chains is designed. Conductance versus Fermi energy level is investigated utilizing the non-equilibrium Green's function approach. If two quantum dots are added on each side of the PCDQD system, additional Breit Wigner and Fano resonances occur in the conductance spectra. If quantum dots are added on one side of the system, small Fano resonances can be observed in the conductance spectra. Adjusting the number of side-coupled quantum dots, the anti-resonance bands emerge at different positions, which makes the system applicable as a quantum switching device. Moreover, the I-V characteristic curve presents the step characteristic and the width of the step decreases with increasing the number of side-coupled quantum dots.
基金Projects 50490270, 50474068, 50674085 supported by the National Natural Science Foundation of China 2005CB221504 by the National Key FoundationResearch Program of China+2 种基金2006BAK04B02, 2006BAK03B06 by the National Science Program of China NCET-06-0478 by the Ministry of Education New Century Outstanding Person Programming of China2006B002 by the Science Foundation of China University of Mining and Technology
文摘Many factors can induce rock burst. Shock energy and shock distance are two key factors affecting rock burst. The 32101 roadway of the Xingcun coal mine, which has a tendency for rock burst, was used as an example. The dynamic module of Itasca’s FLAC (Fast Lagrangian Analysis of Continua) 2D explicit finite-difference software was used to simulate the roadway’s destruction. The vibration velocity and displacements of the rock surrounding the roadway were modeled for different shock energies and hypocenter distances. The simulation results indicate that the vibration velocity and displacement of rock surrounding the roadway have a quadratic relationship to the shock energy and a power law relationship to the distance of the hypocenter from the roadway. A dynamic view of the process was obtained from a series of "snap-shots" collected at 100 different time steps. This shows an isolating "river" is first formed at the hypocenter. The region above the "river" is a low stress zone while below the "river" a high stress zone exists. This high stress zone surrounds the ribs of the roadway in a "double ear" pattern. Continuous and repeated action of the high stress in the "double ear" shaped zone destroys the roadway.
基金the support from the National Natural Science Foundation of China(Nos.11372188,and 51490674)the National Basic Research Program of China(973 Program)(No.2015CB251203)
文摘The flow past a primary cylinder with one tandem control rod and one staggered control rod is simulated in this paper through solving the Navier-Stokes equations. Two examples are simulated to validate the model, and the results matched well with those of previous researches. The Reynolds number based on the diameter of the primary cylinder is 500. The diameter ratio between the control rod and the primary cylinder (d/D) is 0.25. It was found that the effect of the combination of one upstream tandem control rod and one staggered control rod on the hydrodynamics of the primary cylinder is a linear superposition of the effect of a corresponding single control rod, and the effect of the upstream tandem control rod is dominant at larger spacing ratios such as G/D=2. For the combination of a downstream tandem control rod and a staggered control rod, the effect of the control rods is different from that of the corresponding single control rod in the region of 0.2〈G/D〈0.5 & 30°〈a〈120° and 0.9〈G/D〈1.4 & 30°〈a〈50°, where the additional effect is obvious. In this case, the effect of the downstream tandem control rod is dominant at small spacing ratios (such as G/D=0.1). At moderate spacing ratios such as G/D=0.4, the effects of the tandem control rod and the staggered control rod are comparable in both cases.
文摘Synchronization of quantum mechanics with relativity has been considered differently from the present quantum gravity models. It is originated from the roots of philosophy of physics and the basic concepts of relativity & quantum mechanics. It emphasizes the fact that two conscious observers are necessary to experience one conscious moment. Various concepts of consciousness have been discussed and emphasized the necessity for the introduction of a new model of quantum consciousness. A quantum coordinate system has been introduced to explain the present understanding of the phenomena “observation” and “reality”. It has been elaborated that the observation defined by physics is confined to Lorentz space time coordinate system, Minkowski coordinate system and general relativity. But phenomena of observation cannot be completed without considering one more hidden transformation explaining quantum coordinate system which transforms the quantum states into relativistic coordinate system as an interaction between two conscious observers explained by an interactive mechanism of quantum states. A flow chart has been illustrated by a mechanism giving rise to conscious moment and proposed a new model of consciousness. It emphasizes on the fact that “reality” is different from “observation” defined by physics. It affects the relativistic factor of special relativity and suggests a modification for it. If this modified relativistic factor is proved experimentally, the results establish consciousness’s mechanism and a remarkable breakthrough in physics of consciousness studies.
基金supported by the National Natural Science Foundation of China(No.61275103)the Natural Science Foundation of Shanghai(No.18ZR1413600)
文摘A classical ensemble method is used to investigate nonsequential double ionization(NSDI) of Ar atoms irradiated by linearly polarized few-cycle laser pulses. The correlated-electron momentum distribution(CMD) exhibits a strong dependence on the carrier-envelope phase(CEP). When the pulse duration is four cycles, the CMD shows a cross-like structure, which is consistent with experimental results. The CEP dependence is more notable when the laser pulse duration is decreased to two cycles and a special L-shaped structure appears in CMD. Recollision time of returning electrons greatly depends on CEP, which plays a significant role in accounting for the appearance of this structure.
基金Supported by the National Natural Science Foundation of China(41475039)National Key Basic Research and Development (973) Program of China(2015CB953601)
文摘The effects of doubled carbon dioxide on rainfall responses to radiative processes of water clouds are investigated in this study.Two groups of two-dimensional cloud-resolving model sensitivity experiments with regard to pre-summer heavy rainfall around the summer solstice and tropical rainfall around the winter solstice are conducted and their five-day averages over the model domain are analyzed.In the presence of radiative effects of ice clouds,doubled carbon dioxide changes pre-summer rainfall from the decrease associated with the enhanced atmospheric cooling to the increase associated with the enhanced infrared cooling as a result of the exclusion of radiative effects of water clouds.Doubled carbon dioxide leads to the reduction in tropical rainfall,caused by the removal of radiative effects of water clouds through the suppressed infrared cooling.In the absence of radiative effects of ice clouds,doubled carbon dioxide changes pre-summer rainfall from the increase associated with the strengthened atmospheric warming to the decrease associated with the weakened release of latent heat caused by the elimination of radiative effects of water clouds.The exclusion of radiative effects of water clouds increases tropical rainfall through the strengthened infrared cooling,which is insensitive to the change in carbon dioxide.
基金supports of the National Natural Science Foundation of China (Grant No. 50976118)the Shandong Provincial Natural Science Foundation of China (Grant No. ZR2010EM056) are gratefully acknowledged
文摘Using de-ionized ultra-filtered water (DIUFW) as the working fluid, the effects of viscous dissipation in micro-tubes with inner diameters of 19.9μm and 44.2μm, respectively, have been studied by experiments, the theoretical analysis and the numerical simulation at laminar state. Based on thermal imaging technology of micro-area, the temperature rise resulted from the viscous dissipation in microtube is measured by employing IR camera with a specially magnifying lens at different Reynolds numbers. A 2-D model adapted to microtube is presented to simulate the viscous dissipation characteristic considering electric double layer effect (EDL). The investigation shows the calculating results are in rough agreement with the experimental data if removing the experimental uncertainties. Based on the experimental and the numerical simulation results, a viscous dissipation number which can describe the law of the viscous heating in microtube is summed up and it explains the abnormity of the flow resistance in microtubes.
基金the China Scholarship Council for funding a scholarship
文摘Poly(methyl methacrylate)(PMMA)/polystyrene(PS)/carbon black(CB)and poly(ethyl methacrylate)(PEMA)/PS/CB ternary composite films were obtained using solution casting technique to investigate double percolation effect.In both PMMA/PS/CB and PEMA/PS/CB ternary composite films,the CB particles prefer to locate into PS phase based on the results of calculating wetting coefficient,which is also confirmed by SEM images.The conductivity of the films was investigated,and the percolation threshold(¢c)of both ternary composite films with different polymer blend ratios was determined by fitting the McLachlan GEM equation.Conductivity of PMMA/PS/CB ternary composite films showed a typical double percolation effect.However,due to the double emulsion structure of PEMA/PS polymer blends,the PEMA/PS/CB ternary composite films(PEMA/PS=50/50)showed a higher¢c,even CB only located in PS phase,which conflicts with the double percolation effect.A schematic diagram combined with SEM images was proposed to explain this phenomenon.
基金supported by the Training of Outstanding Young Teachers Project in Colleges in Shanghai (No. gjd-07037)
文摘Influences of light irradiation on the negative resistance turn-around characteristics of static induction photosensitive thyristor (SIPTH) have been experimentally and theoretically studied. As the gate current of SIPTH is increased by the light irradiation, the potential barrier in the channel is reduced due to the increase in voltage drop across the gate series resistance. Therefore, SIPTH can be quickly switched from the blocking state to the conducting state by relatively low anode voltage. The optimal matching relation for controlling anode conducting voltage of SIPTH by light irradiation has also been represented.