为倡导绿色出行理念,解决以往研究在处理重复观测数据时容易忽视的潜在相关性和个体异质性问题,针对如何利用智能手机APP提供的多模式出行信息引导小汽车出行者转向停车换乘(Park-and-Ride,P+R)模式进行了探究,同时引入广义线性混合模型...为倡导绿色出行理念,解决以往研究在处理重复观测数据时容易忽视的潜在相关性和个体异质性问题,针对如何利用智能手机APP提供的多模式出行信息引导小汽车出行者转向停车换乘(Park-and-Ride,P+R)模式进行了探究,同时引入广义线性混合模型(Generalized Linear Mixed Model,GLMM)分析了多模式出行信息对小汽车出行者转向P+R意向的影响。首先,基于上海市路网设计意向调查问卷,整合了自驾和P+R两种出行方式的道路拥堵程度、出行时间、停车费用及地铁车厢座位情况等信息,并运用全因子设计法构建了24种不同信息水平组合的假设情景。然后,通过智能手机APP界面示意图向小汽车出行者展示这些多模式出行信息,并收集其转向P+R的意向数据。最后,运用GLMM方法处理同一个体重复决策数据中潜在的相关性和捕捉个体间的异质性。结果显示,GLMM的应用不仅解决了同一个体重复决策间的相关性,还揭示了不同个体对道路拥堵程度和地铁车厢座位情况的差异化关注;智能手机APP整合的多模式出行信息显著提升了小汽车出行者转向P+R的意愿,且这一转变占比达29.2%;高收入、长驾龄以及对P+R政策不了解的出行者转向P+R的意愿较低。研究表明,通过智能手机APP整合自驾和P+R的多模式出行信息能显著增强P+R方式的吸引力,可为提升P+R的普及率提供新思路,有效促进小汽车出行者向绿色出行方式的转变。展开更多
为了提高光伏电池转换效率、降低能量损失,有必要研究最大功率点跟踪(maximum power point tracking,MPPT)方法。针对传统扰动观察法(perturbation observation method,P&O)存在无法兼顾跟踪速度与稳态精度、在光照度发生较大变化...为了提高光伏电池转换效率、降低能量损失,有必要研究最大功率点跟踪(maximum power point tracking,MPPT)方法。针对传统扰动观察法(perturbation observation method,P&O)存在无法兼顾跟踪速度与稳态精度、在光照度发生较大变化时会产生误判现象的问题,文中提出一种能适应环境变化的变步长P&O控制策略。首先,利用光伏电池刚启动时类似恒流源的特性获取当前光照度下的短路电流,通过固定电流法推导出最大功率点(maximum power point,MPP)的参考电压;其次,当光照度突变时,提出功率修正方法,并给出突变时的变步长调整策略;最后,设计基于线性扩张状态观测器(linear extended state observer,LESO)的分数阶比例积分微分(fractional order proportion integration differentiation,FOPID)控制器,可以对算法输出的参考电压进一步进行跟踪补偿。仿真结果表明,所提控制策略可以提高稳态精度和跟踪速度,有效提高光伏电池的输出功率。展开更多
Previously the 5D homogeneous space-time metric was introduced with explicitly given projection operators in matrix form which map the 5D space-time manifold into a Lorentzian space-time. Based on this projection mode...Previously the 5D homogeneous space-time metric was introduced with explicitly given projection operators in matrix form which map the 5D space-time manifold into a Lorentzian space-time. Based on this projection model, vector field and spinor solutions are found to be expressible in terms of SU(2)xL and SU(3)xL, where L is the 4D Lorentz space-time group. The spinor solutions give the SU(2) leptonic states arising from space-time projection, whereas the SU(3) representation arises from conformal projection and gives the quarks, and due to gauge requirement leads to mesons and baryons. This process of mapping the 5D space-time manifold into the 4D space-time is at the basis of an analysis of the recent CERN experimental results, the presence of neutrino oscillations and the observed 125 GeV resonance in the p-p collisions, respectively. In fact, it is found that the spinor solution contains an oscillating phase, and the 125 GeV resonance is shown to be predictable, thereby 1) eliminating the need to introduce a Higgs vacuum, and 2) can be shown possibly to be an indicator for a missing heavy baryon octet.展开更多
Owing to the unique structural,electronic,and physico-chemical properties,molybdenum clusters are expected to play an important role in future nanotechnologies.However,their ground states are still under debate.In thi...Owing to the unique structural,electronic,and physico-chemical properties,molybdenum clusters are expected to play an important role in future nanotechnologies.However,their ground states are still under debate.In this study,the crystal structure analysis by particle swarm optimization(CALYPSO)approach is used for the global minimum search,which is followed by first-principles calculations,to detect an obvious dimerization tendency in Mo_(n)(n=2-18)clusters when the 4s and 4p semicore states are not regarded as the valence states.Further,the clusters with even number of atoms are usually magic clusters with high stability.However,after including the4 s and 4 p electrons as valence electrons,the dimerization tendency exhibits a drastic reduction because the average hybridization indices H_(sp),H_(sd),and H_(pd) are reduced significantly.Overall,this work reports new ground states of Mo_(n)(n=11,14,15)clusters and proves that semicore states are essential for Mo_(n) clusters.展开更多
We employ the coherent thermal states(a kind of entangled states)in thermal field dynamics to establisha complete entangled state formalism expressing pseudo-classical representations of density operator for light fie...We employ the coherent thermal states(a kind of entangled states)in thermal field dynamics to establisha complete entangled state formalism expressing pseudo-classical representations of density operator for light field.Especially,the relationship between the coherent thermal state and the characteristic function and the positive Prepresentation in quantum optics theory are obtained.展开更多
In this paper, the Martin-Hou equation of state is derived by using a power series representation of radial distribution function and an analytic representation of multi-section potential based on the Barker-Henderso...In this paper, the Martin-Hou equation of state is derived by using a power series representation of radial distribution function and an analytic representation of multi-section potential based on the Barker-Henderson hard-particle perturbation theory including high-order terms. In the derivation, a theoretical form of Martin-Hou equation was obtained. It had a similar form and the same capability to predict P-V-T properties as the Martin-Hou equation and no additional data were required for evaluating the constants. The characteristic constants of the theoretical expression have certain relationships with the molecular parameters.展开更多
We study the existence and non-existence of bound states （i.e., solutions in W1,P（RN）） for a class of quasilinear scalar field equations of the for -△pu＋V（x）｜u｜p-2u=a（x）｜u｜q-2u,x∈RN,1〈P〈N,mwhen the po...We study the existence and non-existence of bound states （i.e., solutions in W1,P（RN）） for a class of quasilinear scalar field equations of the for -△pu＋V（x）｜u｜p-2u=a（x）｜u｜q-2u,x∈RN,1〈P〈N,mwhen the potentials V（.）≥ 0 and a（.） decay to zero at infinity.展开更多
Using the shooting argument and an approximating method, this paper isconcerncd with the existence of fast-decay ground state of p-Laplacian equation: Apu＋f(u)=0, in Rn, where f(u) behaves just like f(u) = uq - us, a...Using the shooting argument and an approximating method, this paper isconcerncd with the existence of fast-decay ground state of p-Laplacian equation: Apu＋f(u)=0, in Rn, where f(u) behaves just like f(u) = uq - us, as s>q>np/(n-p) - 1.展开更多
In this paper, authors consider the existence, uniqueness and nonexistence of the radial ground state to the following p-laplacian equation: Delta(p)u + u(q) - \Du\(sigma) = 0, x epsilon Rn, where 2 less than or equal...In this paper, authors consider the existence, uniqueness and nonexistence of the radial ground state to the following p-laplacian equation: Delta(p)u + u(q) - \Du\(sigma) = 0, x epsilon Rn, where 2 less than or equal to p < n, q is subcritical exponent, i.e. p < p* - 1 = [n(p - 1) + p]/(n - p), sigma > 0. Applying the shooting argument, Schauder's fixed point theorem and some delicate estimates of auxiliary funtions, they study the influence of the parameters n, p, q, sigma > 0 on the existence, uniqueness and nonexistence of the radial ground state to the above p-laplacian equation.展开更多
October 19,2007 Vice Premier Wu Yi,PRC On behalf of Chinese government,I would like to congratulate the 20th Foundation of World Federation of Acupuncture-Moxibustion Societies(WFAS)and International Acupuncture Congr...October 19,2007 Vice Premier Wu Yi,PRC On behalf of Chinese government,I would like to congratulate the 20th Foundation of World Federation of Acupuncture-Moxibustion Societies(WFAS)and International Acupuncture Congress which is to be held in Beijing,China.And also I give my warm welcome and regards to TCM/Acupuncture colleagues all over the world.展开更多
After constructing a stress and strain model, the valence bands of in-plane biaxial tensile strained Si is calculated by k·p method. In the paper we calculate the accurate anisotropy valance bands and the splitti...After constructing a stress and strain model, the valence bands of in-plane biaxial tensile strained Si is calculated by k·p method. In the paper we calculate the accurate anisotropy valance bands and the splitting energy between light and heavy hole bands. The results show that the valance bands are highly distorted, and the anisotropy is more obvious. To obtain the density of states （DOS） effective mass, which is a very important parameter for device modeling, a DOS effective mass model of biaxial tensile strained Si is constructed based on the valance band calculation. This model can be directly used in the device model of metal-oxide semiconductor field effect transistor （MOSFET）. It also a provides valuable reference for biaxial tensile strained silicon MOSFET design.展开更多
MgB2 with Tc ≈ 40 K, is a record-breaking compound among the s-p metals and alloys. It appears that this material is a rare example of the two band electronic structures, which are weakly connected with each other. E...MgB2 with Tc ≈ 40 K, is a record-breaking compound among the s-p metals and alloys. It appears that this material is a rare example of the two band electronic structures, which are weakly connected with each other. Experimental results clearly reveal that boron sub-lattice conduction band is mainly responsible for superconductivity in this simple compound. Experiments such as tunneling spectroscopy, specific heat measurements, and high resolution spectroscopy show that there are two superconducting gaps. Considering a canonical two band BCS Hamiltonian containing a Fermi Surface of π- and σ-bands and following Green’s function technique and equation of motion method, we have shown that MgB2 possess two superconducting gaps. It is also pointed out that the system admits a precursor phase of Cooper pair droplets that undergoes a phase locking transition at a critical temperature below the mean field solution. Study of specific heat and density of states is also presented. The agreement between theory and experimental results for specific heat is quite convincing. The paper is organized in five sections: Introduction, Model Hamiltonian, Physical properties, Numerical calculations, Discussion and conclusions.展开更多
文摘为倡导绿色出行理念,解决以往研究在处理重复观测数据时容易忽视的潜在相关性和个体异质性问题,针对如何利用智能手机APP提供的多模式出行信息引导小汽车出行者转向停车换乘(Park-and-Ride,P+R)模式进行了探究,同时引入广义线性混合模型(Generalized Linear Mixed Model,GLMM)分析了多模式出行信息对小汽车出行者转向P+R意向的影响。首先,基于上海市路网设计意向调查问卷,整合了自驾和P+R两种出行方式的道路拥堵程度、出行时间、停车费用及地铁车厢座位情况等信息,并运用全因子设计法构建了24种不同信息水平组合的假设情景。然后,通过智能手机APP界面示意图向小汽车出行者展示这些多模式出行信息,并收集其转向P+R的意向数据。最后,运用GLMM方法处理同一个体重复决策数据中潜在的相关性和捕捉个体间的异质性。结果显示,GLMM的应用不仅解决了同一个体重复决策间的相关性,还揭示了不同个体对道路拥堵程度和地铁车厢座位情况的差异化关注;智能手机APP整合的多模式出行信息显著提升了小汽车出行者转向P+R的意愿,且这一转变占比达29.2%;高收入、长驾龄以及对P+R政策不了解的出行者转向P+R的意愿较低。研究表明,通过智能手机APP整合自驾和P+R的多模式出行信息能显著增强P+R方式的吸引力,可为提升P+R的普及率提供新思路,有效促进小汽车出行者向绿色出行方式的转变。
文摘为了提高光伏电池转换效率、降低能量损失,有必要研究最大功率点跟踪(maximum power point tracking,MPPT)方法。针对传统扰动观察法(perturbation observation method,P&O)存在无法兼顾跟踪速度与稳态精度、在光照度发生较大变化时会产生误判现象的问题,文中提出一种能适应环境变化的变步长P&O控制策略。首先,利用光伏电池刚启动时类似恒流源的特性获取当前光照度下的短路电流,通过固定电流法推导出最大功率点(maximum power point,MPP)的参考电压;其次,当光照度突变时,提出功率修正方法,并给出突变时的变步长调整策略;最后,设计基于线性扩张状态观测器(linear extended state observer,LESO)的分数阶比例积分微分(fractional order proportion integration differentiation,FOPID)控制器,可以对算法输出的参考电压进一步进行跟踪补偿。仿真结果表明,所提控制策略可以提高稳态精度和跟踪速度,有效提高光伏电池的输出功率。
文摘Previously the 5D homogeneous space-time metric was introduced with explicitly given projection operators in matrix form which map the 5D space-time manifold into a Lorentzian space-time. Based on this projection model, vector field and spinor solutions are found to be expressible in terms of SU(2)xL and SU(3)xL, where L is the 4D Lorentz space-time group. The spinor solutions give the SU(2) leptonic states arising from space-time projection, whereas the SU(3) representation arises from conformal projection and gives the quarks, and due to gauge requirement leads to mesons and baryons. This process of mapping the 5D space-time manifold into the 4D space-time is at the basis of an analysis of the recent CERN experimental results, the presence of neutrino oscillations and the observed 125 GeV resonance in the p-p collisions, respectively. In fact, it is found that the spinor solution contains an oscillating phase, and the 125 GeV resonance is shown to be predictable, thereby 1) eliminating the need to introduce a Higgs vacuum, and 2) can be shown possibly to be an indicator for a missing heavy baryon octet.
基金supported by the National Natural Science Foundation of China (No.11404098 and No.11604082)the Student Research Training Program of Henan University of Science and Technology(WLSRTP201911)
文摘Owing to the unique structural,electronic,and physico-chemical properties,molybdenum clusters are expected to play an important role in future nanotechnologies.However,their ground states are still under debate.In this study,the crystal structure analysis by particle swarm optimization(CALYPSO)approach is used for the global minimum search,which is followed by first-principles calculations,to detect an obvious dimerization tendency in Mo_(n)(n=2-18)clusters when the 4s and 4p semicore states are not regarded as the valence states.Further,the clusters with even number of atoms are usually magic clusters with high stability.However,after including the4 s and 4 p electrons as valence electrons,the dimerization tendency exhibits a drastic reduction because the average hybridization indices H_(sp),H_(sd),and H_(pd) are reduced significantly.Overall,this work reports new ground states of Mo_(n)(n=11,14,15)clusters and proves that semicore states are essential for Mo_(n) clusters.
基金the President Foundation of the Chinese Academy of Sciences
文摘We employ the coherent thermal states(a kind of entangled states)in thermal field dynamics to establisha complete entangled state formalism expressing pseudo-classical representations of density operator for light field.Especially,the relationship between the coherent thermal state and the characteristic function and the positive Prepresentation in quantum optics theory are obtained.
基金Zhejiang Provincial Natural Science Foundation of China!(No. 298013)
文摘In this paper, the Martin-Hou equation of state is derived by using a power series representation of radial distribution function and an analytic representation of multi-section potential based on the Barker-Henderson hard-particle perturbation theory including high-order terms. In the derivation, a theoretical form of Martin-Hou equation was obtained. It had a similar form and the same capability to predict P-V-T properties as the Martin-Hou equation and no additional data were required for evaluating the constants. The characteristic constants of the theoretical expression have certain relationships with the molecular parameters.
文摘We study the existence and non-existence of bound states （i.e., solutions in W1,P（RN）） for a class of quasilinear scalar field equations of the for -△pu＋V（x）｜u｜p-2u=a（x）｜u｜q-2u,x∈RN,1〈P〈N,mwhen the potentials V（.）≥ 0 and a（.） decay to zero at infinity.
文摘Using the shooting argument and an approximating method, this paper isconcerncd with the existence of fast-decay ground state of p-Laplacian equation: Apu＋f(u)=0, in Rn, where f(u) behaves just like f(u) = uq - us, as s>q>np/(n-p) - 1.
文摘In this paper, authors consider the existence, uniqueness and nonexistence of the radial ground state to the following p-laplacian equation: Delta(p)u + u(q) - \Du\(sigma) = 0, x epsilon Rn, where 2 less than or equal to p < n, q is subcritical exponent, i.e. p < p* - 1 = [n(p - 1) + p]/(n - p), sigma > 0. Applying the shooting argument, Schauder's fixed point theorem and some delicate estimates of auxiliary funtions, they study the influence of the parameters n, p, q, sigma > 0 on the existence, uniqueness and nonexistence of the radial ground state to the above p-laplacian equation.
文摘October 19,2007 Vice Premier Wu Yi,PRC On behalf of Chinese government,I would like to congratulate the 20th Foundation of World Federation of Acupuncture-Moxibustion Societies(WFAS)and International Acupuncture Congress which is to be held in Beijing,China.And also I give my warm welcome and regards to TCM/Acupuncture colleagues all over the world.
基金supported by the National Natural Science Foundation of China (Grant Nos. 60976068 and 60936005)the Cultivation Fund of the Key Scientific and Technical Innovation Project,Ministry of Education of China (Grant No. 78083)
文摘After constructing a stress and strain model, the valence bands of in-plane biaxial tensile strained Si is calculated by k·p method. In the paper we calculate the accurate anisotropy valance bands and the splitting energy between light and heavy hole bands. The results show that the valance bands are highly distorted, and the anisotropy is more obvious. To obtain the density of states （DOS） effective mass, which is a very important parameter for device modeling, a DOS effective mass model of biaxial tensile strained Si is constructed based on the valance band calculation. This model can be directly used in the device model of metal-oxide semiconductor field effect transistor （MOSFET）. It also a provides valuable reference for biaxial tensile strained silicon MOSFET design.
文摘MgB2 with Tc ≈ 40 K, is a record-breaking compound among the s-p metals and alloys. It appears that this material is a rare example of the two band electronic structures, which are weakly connected with each other. Experimental results clearly reveal that boron sub-lattice conduction band is mainly responsible for superconductivity in this simple compound. Experiments such as tunneling spectroscopy, specific heat measurements, and high resolution spectroscopy show that there are two superconducting gaps. Considering a canonical two band BCS Hamiltonian containing a Fermi Surface of π- and σ-bands and following Green’s function technique and equation of motion method, we have shown that MgB2 possess two superconducting gaps. It is also pointed out that the system admits a precursor phase of Cooper pair droplets that undergoes a phase locking transition at a critical temperature below the mean field solution. Study of specific heat and density of states is also presented. The agreement between theory and experimental results for specific heat is quite convincing. The paper is organized in five sections: Introduction, Model Hamiltonian, Physical properties, Numerical calculations, Discussion and conclusions.
