We compared two different strategies to increase the catches oflps typographus (L.), particularly males, in pheromone-baited traps. The first of these strategies, the barrier approach, used alternating pheromone ble...We compared two different strategies to increase the catches oflps typographus (L.), particularly males, in pheromone-baited traps. The first of these strategies, the barrier approach, used alternating pheromone blends, targeting males and females respectively, in closely-spaced traps forming a barrier around forest stands. The second strategy, the single trap approach, used widely-spaced traps that were all baited with the same lure and intended to trap the highest possible numbers of males without compromising trapping of females. In the blend used for the barrier traps targeting primarily males, with a lower percentage of (4S)-cis-verbenol (cV), the (-)-α-pinene was replaced step wise with (+)-limonene at rates of 0%, 1%, 10%, 35%, 60% and 90%. This replacement had no significant effect on the numbers of responding 1. typographus males, but there was a slight effect on the percentage of males caught. In the attractant blend for the barrier traps targeting females, with a higher percentage of cV, the 2-methyl-3-buten-2-ol (MB) was replaced with 1-methoxy-2-propanol (MP) in a similar fashion as for the male-specific blends. The replacement did not significantly affect the catch of females. Thus, it is pos- sible to use the MP in the blend with cV and ipsdienol without significant change in catch efficacy. In the blends for single traps, the (-)-α- pinene was replaced with (+)-limonene and MB with MP. The replacement of (-)-α-pinene had only a slight effect on the percentage of males, but the results suggest that replacing MB with MP in the blend will not significantly reduce trapping efficacy.展开更多
In order to determine whether growth performance could be improved by hybridizing full-sib families of Manila clam (Ruditapes philippinarum), crosses between two full-sib families including self and reciprocal cross...In order to determine whether growth performance could be improved by hybridizing full-sib families of Manila clam (Ruditapes philippinarum), crosses between two full-sib families including self and reciprocal crosses were carried out. The effects of heterosis, combining ability and interaction on the growth of shell length were estimated. The results showed that the growth of hybrid larvae was intermediate between parents on days 6 and 9. Heterosis on shell length was observed, which varied at juvenile stage. The cross of ♂A×♀B (Hp varied between 10.41% and 68.27%) displayed larger heterosis than ♂A×♀B (Hp varied between 1.89% and 32.33%) did, suggesting that ♂A×♀B was an ideal hatchery method of improving the growth performance of Manila clam. The variances of general combining ability (GCA), special combining ability (SCA) and interaction (I) were significant in shell length (P〈 0.05), indicating that both additive and non-additive genetic factors were important contributors to the growth of larvae and juveniles. The GCA for shell length of ♂A×♀B was higher than that of ♂A×♀B at both larval and juvenile stages. This con- firmed that the cross between ♂A and ♀B showed great growth in shell length. In summary, the growth of Manila clam seeds could be improved by hybridizing selected parents from large numbers of full-sib families.展开更多
This article discusses the separability of the pure states and mixed states of the quantum network of two nodes by means of the criterion of no entanglement in terms of the covariance correlation tensor in quantum net...This article discusses the separability of the pure states and mixed states of the quantum network of two nodes by means of the criterion of no entanglement in terms of the covariance correlation tensor in quantum network theory, i.e. for a composite system consisting of two nodes. The covariance correlation tensor is equal to zero for all possible and .展开更多
It has been evident that the theory and methods of dynamic derivatives are playing an increasingly important role in hybrid modeling and computations. Being constructed on various kinds of hybrid grids, that is, tim...It has been evident that the theory and methods of dynamic derivatives are playing an increasingly important role in hybrid modeling and computations. Being constructed on various kinds of hybrid grids, that is, time scales, dynamic derivatives offer superior accuracy and flexibility in approximating mathematically important natural processes with hard-to-predict singularities, such as the epidemic growth with unpredictable jump sizes and option market changes with high uncertainties, as compared with conventional derivatives. In this article, we shall review the novel new concepts, explore delicate relations between the most frequently used second-order dynamic derivatives and conventional derivatives. We shall investigate necessary conditions for guaranteeing the consistency between the two derivatives. We will show that such a consistency may never exist in general. This implies that the dynamic derivatives provide entirely different new tools for sensitive modeling and approximations on hybrid grids. Rigorous error analysis will be given via asymptotic expansions for further modeling and computational applications. Numerical experiments will also be given.展开更多
We have studied the single-neutron stripping reaction induced by ^23O on carbon target at beam energy of 72 MeV//A with a motive to analyze its ground state structure. The partial stripping cross sections as well as l...We have studied the single-neutron stripping reaction induced by ^23O on carbon target at beam energy of 72 MeV//A with a motive to analyze its ground state structure. The partial stripping cross sections as well as longitudinal momentum distribution of ^22O core have been calculated within the framework of the eikonal approximation approach. Several core-neutron spin coupling configurations, corresponding to J^π= 1/2 + as ground state spin parity of ^23O, along with their suitable admixtures have been considered. The major outcome of the present work is that the s and d admixed configuration with a large contribution of s state seems to explain the longitudinal momentum distribution data more satisfactorily.展开更多
In order to investigate the eutrophication degree of Yuqiao Reservoir, a hybrid method, combining principal component regression (PCR) and artificial neural network (ANN), was adopted to predict chlorophyll-a concentr...In order to investigate the eutrophication degree of Yuqiao Reservoir, a hybrid method, combining principal component regression (PCR) and artificial neural network (ANN), was adopted to predict chlorophyll-a concentration of Yuqiao Reservoir’s outflow. The data were obtained from two sampling sites, site 1 in the reservoir, and site 2 near the dam. Seven water variables, namely chlorophyll-a concentration of site 2 at time t and that of both sites 10 days before t, total phosphorus(TP), total nitrogen(TN),...展开更多
Recovering waste heat from industrial processes is bene ficial in order to reduce the primary energy demands and heat pumps can be used to this purpose.Absorption heat pumps are energy-saving and environment-friendly ...Recovering waste heat from industrial processes is bene ficial in order to reduce the primary energy demands and heat pumps can be used to this purpose.Absorption heat pumps are energy-saving and environment-friendly because use working fluids that do not cause ozone depletion and can reduce the global warming emissions.The hybrid heat pump processes combine the conventional vapor-compression and the absorption heat pump cycles.Studies about the simulations and modeling of hybrid heat pumps are few in literature.In this research a mathematical model for single effect absorption and hybrid heat pump is carried out with Chem Cad? 6.0.1.LiBr–H_2O is used as working fluid while electrolytic NRTL and electrolytes latent heat are used as thermodynamic model due to the better results.Binary parameters of activity coef ficients are regressed from experimental vapor pressure data while default constants are used for the solubility expressions.A design of heat pumps is developed and a new modeling of generator is analyzed.The coef ficient of performance of absorption heat pump and hybrid heat pump is equal to 0.7 and 0.83 respectively.For absorption heat pump a sensitivity analysis is carried out to evaluate the effect of temperature and pressure generator,the concentration of Li–Br solution on coef ficient of performance,cooling capacity and working fluid temperature.For hybrid heat pump,the different coef ficients of performance,the primary energy ratio,the generator heat,and the compressor power are analyzed for different values of compressor proportion.Results show that comparing the two systems the hybrid pump allows to save more primary energy,costs and carbon dioxide emissions with respect to absorption heat pump with the increasing of compressor proportion parameter.Future researches should focus on the construction of this heat pumps integrated in chemical processes as a biogas plant or trigeneration systems.展开更多
The purpose of the present study is to establish a mixed lubrication model for the journal-thrust coupled microgroove bearings(also referred as coupled bearings)used for the ship shaftless rim-driven thrusters.During ...The purpose of the present study is to establish a mixed lubrication model for the journal-thrust coupled microgroove bearings(also referred as coupled bearings)used for the ship shaftless rim-driven thrusters.During the hydrodynamic modelling,the coupling hydrodynamic pressure between the journal bearing and the thrust bearing is considered.The mixed lubrication performances of the microgroove journal-thrust bearing with five different bottom shapes,including rectangle,semi-ellipse,right triangle,isosceles triangle and left triangle,are compared.Based on the numerical results,the optimal microgroove bottom shape of the journal bearing and tilting angle of the thrust pad are determined.Additionally,the comparative analysis shows that the coupled bearing with left triangle microgroove bottom shape exhibits the optimal mixed lubrication performance.The numerical result also indicates that the optimal inclination angle of the thrust bearing pad is 0.01°for the current simulation case.展开更多
The lepton flavor violating process μ - eγ has been previously studied in a model of electroweak-scale right-handed neutrinos. In that work the decay amplitude was computed in unitarity gauge, augmented by some tech...The lepton flavor violating process μ - eγ has been previously studied in a model of electroweak-scale right-handed neutrinos. In that work the decay amplitude was computed in unitarity gauge, augmented by some technical considerations that correct the leading term thus obtained. This complication arises because the mixing matrices appearing in the weak charged currents are not unitary in the model. In this paper, we recalculate the amplitude in Re gauge. The cancellation of the ξ dependence in the final result serves as a useful check to both the obtained amplitude and the technical points made in the previous work.展开更多
The mixing enthalpies and structural order in liquid Mg−Si system were investigated via ab-initio molecular dynamics at 1773 K.By calculating the transferred charges and electron density differences,the dominance of S...The mixing enthalpies and structural order in liquid Mg−Si system were investigated via ab-initio molecular dynamics at 1773 K.By calculating the transferred charges and electron density differences,the dominance of Si−Si interactions in the chemical environments around Si was demonstrated,which determined that the mixing enthalpy reached the minimum on Mg-rich side.In terms of Honeycutt and Anderson(HA)bond pairs based on the partial pair correlation functions,the attraction between Si−Si pairs and Mg atoms was revealed,and the evolution of structural order with Si content was characterized as a process of constituting frame structures by Si−Si pairs that dispersed Mg atoms.Focusing on tetrahedral order of local Si-configurations,a correlation between the mixing enthalpy and structural order was uncovered ultimately,which provided a new perspective combining the energetics with geometry to understand the liquid Mg−Si binary system.展开更多
In order to analyze the effect of different loading frequencies on the fatigue performance for asphalt mixture,the changing law of asphalt mixture strengths with loading speed was revealed by strength tests under diff...In order to analyze the effect of different loading frequencies on the fatigue performance for asphalt mixture,the changing law of asphalt mixture strengths with loading speed was revealed by strength tests under different loading speeds.Fatigue equations of asphalt mixtures based on the nominal stress ratio and real stress ratio were established using fatigue tests under different loading frequencies.It was revealed that the strength of the asphalt mixture is affected by the loading speed greatly.It was also discovered that the fatigue equation based on the nominal stress ratio will change with the change of the fatigue loading speed.There is no uniqueness.But the fatigue equation based on the real stress ratio doesn't change with the loading frequency.It has the uniqueness.The results indicate the fatigue equation based on the real stress ratio can realize the normalization of the asphalt mixture fatigue equation under different loading frequencies.It can greatly benefit the analysis of the fatigue characteristics under different vehicle speeds for asphalt pavement.展开更多
The objective of this paper is to discuss the issue of the projection uniformity of asymmetric fractional factorials.On the basis of Lee discrepancy,the authors define the projection Lee discrepancy to measure the uni...The objective of this paper is to discuss the issue of the projection uniformity of asymmetric fractional factorials.On the basis of Lee discrepancy,the authors define the projection Lee discrepancy to measure the uniformity for low-dimensional projection designs.Moreover,the concepts of uniformity pattern and minimum projection uniformity criterion are proposed,which can be used to assess and compare two and three mixed levels factorials.Statistical justification of uniformity pattern is also investigated.展开更多
As an advanced generation instrument of earth observation,small footprint full waveform light detection and ranging(LiDAR) technology has been widely used in the past few years.Decomposition and radiative correction i...As an advanced generation instrument of earth observation,small footprint full waveform light detection and ranging(LiDAR) technology has been widely used in the past few years.Decomposition and radiative correction is an important step in waveform data processing,it influences the accuracy of both information extraction and further applications.Based on a stepwise strategy,this study adopts Gaussian mixture model to approximate the LiDAR waveform.In addition to waveform decomposition,a relative correction model is proposed in this paper,the model considers the transmit pulses as well as the different of the travel path for implementing LiDAR waveform relative correction.Validation of the stepwise decomposition and relative correction model are carried out on LiDAR waveform acquired over Zhangye,China.The results indicate that stepwise decomposition identified the number of peaks in LiDAR waveforms,center position and width of each peak well.The relative radiometric correction also improves the similarity of waveforms which acquired at the same target.展开更多
A basic equation system for meridional throughflow fields in multistage axial flow compressors has been deduced, containing many unknown correlation terms,which describe different kinds of spanwise mixing mechanism in...A basic equation system for meridional throughflow fields in multistage axial flow compressors has been deduced, containing many unknown correlation terms,which describe different kinds of spanwise mixing mechanism in a unified form.The equation system shows that spanwise mixing of meridional flows in compressors is attributed to three kinds of mechanism:molecular motion,turbulent diffusion,and circumferential non-uniformities,the last of which includes secondary flow effects and others.Therefore the equation system unifies the two models for spanwise mixing analyses by Adkins & Smith (1981) and Gallimore & Cumpsty (1986).With three kinds of apparent mixing coefficients defined and introduced into the basic equation system,a novel,much simpler equation system,without additional unknown correlation terms included,has been obtained.This novel equa- tion system makes throughflow computations including mixing far easier for multistage compressors.It has been rigorously shown that these apparent mixing coefficients contain full information of all the three kinds of mixing mechanism,so that the simpler equation system can also be taken as a unified model for meridional flows with all the kinds of the mixing effects.Calculations of the flow through multistage machines have been made by incorporating the new model into a streamline curvature throughflow calculation method and the improved agreement with experimental data has been obtained.It is believed that the simpler equation system can be applied to the flows not only in subsonic but in transonic and supersonic compressors if an appropriate model is proposed for the apparent mixing coefficients.展开更多
The strong consistency of M estimators of the regression parameters in linear models for ρ-mixing random errors under some mild conditions is established, which is an essential improvement over the relevant results i...The strong consistency of M estimators of the regression parameters in linear models for ρ-mixing random errors under some mild conditions is established, which is an essential improvement over the relevant results in the literature on the moment conditions and mixing errors. Especially, Theorem of Wu (2005) is improved essentially on the moment conditions.展开更多
基金supported by Slovak Research and Development Agency (APVV-51-P06005 and APVV-27-P05205)the Scientific Grant Agency of the Ministry of Education of the Slovak Republic and the Slovak Academy of Sciences (2/6153/26)
文摘We compared two different strategies to increase the catches oflps typographus (L.), particularly males, in pheromone-baited traps. The first of these strategies, the barrier approach, used alternating pheromone blends, targeting males and females respectively, in closely-spaced traps forming a barrier around forest stands. The second strategy, the single trap approach, used widely-spaced traps that were all baited with the same lure and intended to trap the highest possible numbers of males without compromising trapping of females. In the blend used for the barrier traps targeting primarily males, with a lower percentage of (4S)-cis-verbenol (cV), the (-)-α-pinene was replaced step wise with (+)-limonene at rates of 0%, 1%, 10%, 35%, 60% and 90%. This replacement had no significant effect on the numbers of responding 1. typographus males, but there was a slight effect on the percentage of males caught. In the attractant blend for the barrier traps targeting females, with a higher percentage of cV, the 2-methyl-3-buten-2-ol (MB) was replaced with 1-methoxy-2-propanol (MP) in a similar fashion as for the male-specific blends. The replacement did not significantly affect the catch of females. Thus, it is pos- sible to use the MP in the blend with cV and ipsdienol without significant change in catch efficacy. In the blends for single traps, the (-)-α- pinene was replaced with (+)-limonene and MB with MP. The replacement of (-)-α-pinene had only a slight effect on the percentage of males, but the results suggest that replacing MB with MP in the blend will not significantly reduce trapping efficacy.
基金supported by the earmarked fund for Modern Agro-industry Technology Research System (CARS-48)grants from the ‘863’ Project of China (2012AA10AA400)
文摘In order to determine whether growth performance could be improved by hybridizing full-sib families of Manila clam (Ruditapes philippinarum), crosses between two full-sib families including self and reciprocal crosses were carried out. The effects of heterosis, combining ability and interaction on the growth of shell length were estimated. The results showed that the growth of hybrid larvae was intermediate between parents on days 6 and 9. Heterosis on shell length was observed, which varied at juvenile stage. The cross of ♂A×♀B (Hp varied between 10.41% and 68.27%) displayed larger heterosis than ♂A×♀B (Hp varied between 1.89% and 32.33%) did, suggesting that ♂A×♀B was an ideal hatchery method of improving the growth performance of Manila clam. The variances of general combining ability (GCA), special combining ability (SCA) and interaction (I) were significant in shell length (P〈 0.05), indicating that both additive and non-additive genetic factors were important contributors to the growth of larvae and juveniles. The GCA for shell length of ♂A×♀B was higher than that of ♂A×♀B at both larval and juvenile stages. This con- firmed that the cross between ♂A and ♀B showed great growth in shell length. In summary, the growth of Manila clam seeds could be improved by hybridizing selected parents from large numbers of full-sib families.
文摘This article discusses the separability of the pure states and mixed states of the quantum network of two nodes by means of the criterion of no entanglement in terms of the covariance correlation tensor in quantum network theory, i.e. for a composite system consisting of two nodes. The covariance correlation tensor is equal to zero for all possible and .
文摘It has been evident that the theory and methods of dynamic derivatives are playing an increasingly important role in hybrid modeling and computations. Being constructed on various kinds of hybrid grids, that is, time scales, dynamic derivatives offer superior accuracy and flexibility in approximating mathematically important natural processes with hard-to-predict singularities, such as the epidemic growth with unpredictable jump sizes and option market changes with high uncertainties, as compared with conventional derivatives. In this article, we shall review the novel new concepts, explore delicate relations between the most frequently used second-order dynamic derivatives and conventional derivatives. We shall investigate necessary conditions for guaranteeing the consistency between the two derivatives. We will show that such a consistency may never exist in general. This implies that the dynamic derivatives provide entirely different new tools for sensitive modeling and approximations on hybrid grids. Rigorous error analysis will be given via asymptotic expansions for further modeling and computational applications. Numerical experiments will also be given.
文摘We have studied the single-neutron stripping reaction induced by ^23O on carbon target at beam energy of 72 MeV//A with a motive to analyze its ground state structure. The partial stripping cross sections as well as longitudinal momentum distribution of ^22O core have been calculated within the framework of the eikonal approximation approach. Several core-neutron spin coupling configurations, corresponding to J^π= 1/2 + as ground state spin parity of ^23O, along with their suitable admixtures have been considered. The major outcome of the present work is that the s and d admixed configuration with a large contribution of s state seems to explain the longitudinal momentum distribution data more satisfactorily.
文摘In order to investigate the eutrophication degree of Yuqiao Reservoir, a hybrid method, combining principal component regression (PCR) and artificial neural network (ANN), was adopted to predict chlorophyll-a concentration of Yuqiao Reservoir’s outflow. The data were obtained from two sampling sites, site 1 in the reservoir, and site 2 near the dam. Seven water variables, namely chlorophyll-a concentration of site 2 at time t and that of both sites 10 days before t, total phosphorus(TP), total nitrogen(TN),...
文摘Recovering waste heat from industrial processes is bene ficial in order to reduce the primary energy demands and heat pumps can be used to this purpose.Absorption heat pumps are energy-saving and environment-friendly because use working fluids that do not cause ozone depletion and can reduce the global warming emissions.The hybrid heat pump processes combine the conventional vapor-compression and the absorption heat pump cycles.Studies about the simulations and modeling of hybrid heat pumps are few in literature.In this research a mathematical model for single effect absorption and hybrid heat pump is carried out with Chem Cad? 6.0.1.LiBr–H_2O is used as working fluid while electrolytic NRTL and electrolytes latent heat are used as thermodynamic model due to the better results.Binary parameters of activity coef ficients are regressed from experimental vapor pressure data while default constants are used for the solubility expressions.A design of heat pumps is developed and a new modeling of generator is analyzed.The coef ficient of performance of absorption heat pump and hybrid heat pump is equal to 0.7 and 0.83 respectively.For absorption heat pump a sensitivity analysis is carried out to evaluate the effect of temperature and pressure generator,the concentration of Li–Br solution on coef ficient of performance,cooling capacity and working fluid temperature.For hybrid heat pump,the different coef ficients of performance,the primary energy ratio,the generator heat,and the compressor power are analyzed for different values of compressor proportion.Results show that comparing the two systems the hybrid pump allows to save more primary energy,costs and carbon dioxide emissions with respect to absorption heat pump with the increasing of compressor proportion parameter.Future researches should focus on the construction of this heat pumps integrated in chemical processes as a biogas plant or trigeneration systems.
基金Project(51975064)supported by the National Natural Science Foundation of ChinaProject(cstc2018jcyj AX0442)supported by the General Projects of Basic Science and Frontier Technology Research of Chongqing,China+2 种基金Projects(2018M631059,2019T120805)supported by the Postdoctoral Science Foundation of ChinaProject(cstc2017zdcyzdzx X0001)supported by the Major Research and Development Program of ChinaProject supported by the Innovation Program on the Common and Key Technologise of Key Industries,China。
文摘The purpose of the present study is to establish a mixed lubrication model for the journal-thrust coupled microgroove bearings(also referred as coupled bearings)used for the ship shaftless rim-driven thrusters.During the hydrodynamic modelling,the coupling hydrodynamic pressure between the journal bearing and the thrust bearing is considered.The mixed lubrication performances of the microgroove journal-thrust bearing with five different bottom shapes,including rectangle,semi-ellipse,right triangle,isosceles triangle and left triangle,are compared.Based on the numerical results,the optimal microgroove bottom shape of the journal bearing and tilting angle of the thrust pad are determined.Additionally,the comparative analysis shows that the coupled bearing with left triangle microgroove bottom shape exhibits the optimal mixed lubrication performance.The numerical result also indicates that the optimal inclination angle of the thrust bearing pad is 0.01°for the current simulation case.
文摘The lepton flavor violating process μ - eγ has been previously studied in a model of electroweak-scale right-handed neutrinos. In that work the decay amplitude was computed in unitarity gauge, augmented by some technical considerations that correct the leading term thus obtained. This complication arises because the mixing matrices appearing in the weak charged currents are not unitary in the model. In this paper, we recalculate the amplitude in Re gauge. The cancellation of the ξ dependence in the final result serves as a useful check to both the obtained amplitude and the technical points made in the previous work.
基金The authors are grateful for the financial supports from the National Key Research and Development Program of China(2016YFB0701202)the National Natural Science Foundation of China(51901117,51801116,51804190,and 11804179)the Shandong Provincial Key Research and Development Plan,China(2019GGX102047).
文摘The mixing enthalpies and structural order in liquid Mg−Si system were investigated via ab-initio molecular dynamics at 1773 K.By calculating the transferred charges and electron density differences,the dominance of Si−Si interactions in the chemical environments around Si was demonstrated,which determined that the mixing enthalpy reached the minimum on Mg-rich side.In terms of Honeycutt and Anderson(HA)bond pairs based on the partial pair correlation functions,the attraction between Si−Si pairs and Mg atoms was revealed,and the evolution of structural order with Si content was characterized as a process of constituting frame structures by Si−Si pairs that dispersed Mg atoms.Focusing on tetrahedral order of local Si-configurations,a correlation between the mixing enthalpy and structural order was uncovered ultimately,which provided a new perspective combining the energetics with geometry to understand the liquid Mg−Si binary system.
基金Projects(51208066,51038002)supported by the National Natural Science Foundation of ChinaProject(20114316120001)supported by Specialized Research Fund for the Doctoral Program of Higher Education,China+5 种基金Project(2012-319-825-150)supported by Application and Basic Research Projects of Ministry of Transport ChinaProject(2013K28)supported by Transportation Science and Technology Plan Projects of Henan Province,ChinaProject(201102)supported by Transportation Science and Technology Plan Projects of Hunan Province,ChinaProject(YB2012B031)supported by Funding Projects of Hunan Provincial Outstanding Doctorate Dissertation,ChinaProject(2014gxjgclkf-002)supported by Open Fund of Key Laboratory of Road Structure and Material of Guangxi Province ChinaProject(kfj120101)supported by Open Fund of the Key Laboratory of Highway Engineering(Changsha University of Science and Technology),China
文摘In order to analyze the effect of different loading frequencies on the fatigue performance for asphalt mixture,the changing law of asphalt mixture strengths with loading speed was revealed by strength tests under different loading speeds.Fatigue equations of asphalt mixtures based on the nominal stress ratio and real stress ratio were established using fatigue tests under different loading frequencies.It was revealed that the strength of the asphalt mixture is affected by the loading speed greatly.It was also discovered that the fatigue equation based on the nominal stress ratio will change with the change of the fatigue loading speed.There is no uniqueness.But the fatigue equation based on the real stress ratio doesn't change with the loading frequency.It has the uniqueness.The results indicate the fatigue equation based on the real stress ratio can realize the normalization of the asphalt mixture fatigue equation under different loading frequencies.It can greatly benefit the analysis of the fatigue characteristics under different vehicle speeds for asphalt pavement.
基金supported by the National Natural Science Foundations of China under Grant Nos.11271147 and 11401596
文摘The objective of this paper is to discuss the issue of the projection uniformity of asymmetric fractional factorials.On the basis of Lee discrepancy,the authors define the projection Lee discrepancy to measure the uniformity for low-dimensional projection designs.Moreover,the concepts of uniformity pattern and minimum projection uniformity criterion are proposed,which can be used to assess and compare two and three mixed levels factorials.Statistical justification of uniformity pattern is also investigated.
基金supported by Major State Basic Research Development Program of China(Grant No.2007CB714406)National Key Technology R&D Program of China(Grant No.2008BAC34B03)
文摘As an advanced generation instrument of earth observation,small footprint full waveform light detection and ranging(LiDAR) technology has been widely used in the past few years.Decomposition and radiative correction is an important step in waveform data processing,it influences the accuracy of both information extraction and further applications.Based on a stepwise strategy,this study adopts Gaussian mixture model to approximate the LiDAR waveform.In addition to waveform decomposition,a relative correction model is proposed in this paper,the model considers the transmit pulses as well as the different of the travel path for implementing LiDAR waveform relative correction.Validation of the stepwise decomposition and relative correction model are carried out on LiDAR waveform acquired over Zhangye,China.The results indicate that stepwise decomposition identified the number of peaks in LiDAR waveforms,center position and width of each peak well.The relative radiometric correction also improves the similarity of waveforms which acquired at the same target.
文摘A basic equation system for meridional throughflow fields in multistage axial flow compressors has been deduced, containing many unknown correlation terms,which describe different kinds of spanwise mixing mechanism in a unified form.The equation system shows that spanwise mixing of meridional flows in compressors is attributed to three kinds of mechanism:molecular motion,turbulent diffusion,and circumferential non-uniformities,the last of which includes secondary flow effects and others.Therefore the equation system unifies the two models for spanwise mixing analyses by Adkins & Smith (1981) and Gallimore & Cumpsty (1986).With three kinds of apparent mixing coefficients defined and introduced into the basic equation system,a novel,much simpler equation system,without additional unknown correlation terms included,has been obtained.This novel equa- tion system makes throughflow computations including mixing far easier for multistage compressors.It has been rigorously shown that these apparent mixing coefficients contain full information of all the three kinds of mixing mechanism,so that the simpler equation system can also be taken as a unified model for meridional flows with all the kinds of the mixing effects.Calculations of the flow through multistage machines have been made by incorporating the new model into a streamline curvature throughflow calculation method and the improved agreement with experimental data has been obtained.It is believed that the simpler equation system can be applied to the flows not only in subsonic but in transonic and supersonic compressors if an appropriate model is proposed for the apparent mixing coefficients.
基金This research is supported by the National Natural Science Foundation of China under Grant No. 11061012, the Support Program of the New Century Guangxi China Ten-hundred-thousand Talents Project under Grant No. 2005214, and the Guangxi, China Science Foundation under Grant No. 0991081.
文摘The strong consistency of M estimators of the regression parameters in linear models for ρ-mixing random errors under some mild conditions is established, which is an essential improvement over the relevant results in the literature on the moment conditions and mixing errors. Especially, Theorem of Wu (2005) is improved essentially on the moment conditions.