检索结果-南通市图书馆

Spontaneous ignition of corrugated cardboard under dynamic high radiant flux

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第10期40卷 65-77页

作者： Liu Liu Yan Gu Hong Yang Xing Wang Yang Zhou xiaogan Dai Yong Han Shanggang Wen Ming Li Congmei Lin Changgen Feng Fei Tang Yushi Wen Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621999China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Fire Science University of Science and Technology of ChinaHefei 230026China Institute of Applied physics and Computational Mathematics China Academy of Engineering PhysicsBeijing 100088China

Understanding the response of solid combustibles under high radiant fluxes is critical in predicting the thermal damage from extreme *** the more moderate radiant fluxes in conventional hydrocarbon fires,extreme events such as strong explosion,concentrated sunlight and directed energy can generate dynamic radiant fluxes at the MW/m^(2. level,creating a unique threat to *** study investigates the pyrolysis and spontaneous ignition behaviors of corrugated cardboard by using both experimental and numerical methods,under 10-cm dynamic high radiant fluxes ranging from 0.2.to 1.2. MW/m^(2. for 10 *** spontaneous ignition process at dynamic high radiant fluxes was recorded and *** ignition modes were found at the critical radiant flux of 0.4 MW/m^(2.,namely hot-gas spontaneous ignition and hot-residue piloted *** latter is not the focus of this paper due to its extremely small probability of *** research reveals that the increase in flux intensity induces shorter delay times for both pyrolysis and ignition,lower ignition energy density,along with a corresponding rise in the critical mass flux and surface temperature at ignition *** simulation results are generally aligned with the experimental findings,despite some divergences may be attributed to model simplifications and parameter *** work contributes to a deeper insight into material behavior under extreme radiation,with valuable implications for fire safety and hazard assessment.

关键词： Extreme radiation Fire safety Corrugated cardboard Pyrolysis Ignition temperature

Output Rate of Atomic Four-Wave Mixing in Two-Component Bose-Einstein Condensate

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2004年第5期41卷 695-698页

作者： LI Jia-Hua~1 LI Wei-Bing~1 PENG Ju-Cun~2.1 department of physics,Huazhong{2. of Science and Technology,Wuhan 430074,China2.department of physics,xiaogan Normal{2.,xiaogan 432.00,China department of physics Huazhong University of Science and Technology Wuhan 430074 China department of physics Xiaogan Normal University Xiaogan 432100 China

In this letter,following the proposal of Heurich et al.[***.A63(2.01)033605],we analyze anddiscuss output rate of atomic four-wave mixing in the two-component Bose-Einstein condensate under the condition ofthe steady *** results show that the magnitude of the signal beam increases with the increase of the intensityof the probe beam,up to a saturated value,then it decreases as the probe beam *** influence of theinteraction range on the signal beam is also *** particular,it is worth while pointing out that in contrast tothe previous solutions,our obtained analytical solutions are of very simple and explicit forms,which open the door forfurther investigating the related physical mechanisms.

关键词： atomic four-wave mixing steady state Bose-Einstein condensate

Density-functional formula for strongly correlated systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2005年第5期15卷 395-401页

作者： WANG Huaiyu1*, HAN Rushan2.and CHEN Nanxian1(1. department of physics, Tsinghua{2., Beijing 100084, China 2. department of physics, Peking{2., Beijing 100871, China) Dept. of Phys. Tsinghua Univ. Beijing 100084 China Dept. of Phys. Peking Univ. Beijing 100871 China

Density functional method is applied for strongly correlated systems. Based on the assumption that the systems are composed of electrons in singly-occupied orbitals and those in doubly-occupied orbitals, a set of self-consistent equations are obtained by standard variation procedure. The equations consist of two parts. One part is to solve the wave functions of the electrons in singly-occupied orbitals and the other is to solve the wave functions of the electrons in doubly-occupied orbitals. The physical meanings of the terms appearing in the equations are discussed.

关键词： density-functional theory strongly correlated systems doubly-occupied orbital two-particle wave function self-consistent equations.

Effect of an impurity on 3-electron quantum dots in magnetic fields

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2004年第5期47卷 521-530页

作者： LIU Yimin1,2. HUANG Gangming1 & BAO Chengguang1 1. department of physics, Zhongshan{2., Guangzhou 5102.5, China 2. department of physics, Shaoguan{2., Shaoguan 512.05, China department of physics Zhongshan University Guangzhou China department of physics Shaoguan University Shaoguan China

The ground-state property of a 2.dimensional 3-electron quantum dot (QD) subjected to an external magnetic fieldB and affected by an impurity is studied. The impurity is located at thez-axis by a distanced from the plane of the dot. The evolution of the angular momentumL o and the spinS o of the ground state in accordance withB andd has been calculated, and the results are summarized and plotted in a (L o,S o) diagram. The spatial distribution of the electrons (the size and the geometric features) and the optical absorption have also been investigated. The (L o S o) diagram indicates thatL o andS o may jump whend and/orB vary. It was found that, due to the constraints arising from symmetry, each symmetric geometry is accessible only to a specific group of states having specificL o andS o.

关键词： quantum dot, ground state, charged impurity, magnetic field.

Anisotropic effect on the vibronic reduction factors

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2006年第21期51卷 2553-2558页

作者： QIU Qing-chun1,2.& QIAO Fen1,2.1. department of physics and IT, Medical College, Shantou{2.,Shantou 515041, China 2. department of physics, Shantou{2., Shantou 515063, China department of physics and IT Medical College Shantou University Shantou China department of physics Shantou University Shantou China

The reduction factors p and q defined by Ham in the Ee JT system and their relation 2.-p=1 have been well accepted and the concept of reduction factors is widely used in the studies of vibronic coupling. However, when the system is under the anisotropic conditions, the reduction factors and their relation will change accordingly. The first-order reduction factors p and q of Ee system were further studied using the method of unitary transformation here. The relation between p and q proposed by Ham was investigated under both conditions of the linear coupling and the anisotropic effects. The result demonstrated that the relation of 2.-p=1 was only correct for the linear vibronic coupling, but not correct when the anisotropic effect was considered. This result suggested that the anisotropic effect influence considerably the reduction factors, and hence the physical properties of materials. Our method could be also applied to other JT systems, especially the highly symmetric JT systems involving C60 molecules.

关键词：电子振动耦合声子交迭 Jahn-Teller效应各向异性

Potential energy surfaces for low-lying electronic states of SO_2

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2006年第4期49卷 289-295页

作者： LI Anyang1, SUO Bing2. WEN Zhenyi2.& WANG Yubin2.1. Shanxi Key Laboratory of Physico-inorganic Chemistry, department of Chemistry, Northwest university, Xi’an 710069, China 2. Institute of Modern{2., Northwest university, Xi’an 710069, China Shanxi Key Laboratory of Physico-inorganic Chemistry Department of Chemistry Northwest University Xi’an China Institute of Modern physics Northwest University Xi’an China

The potential energy surfaces for the nine low-lying electronic states of SO2.have been constructed by using the multi-reference second order perturbation theory (MRPT2. with the basis set cc-pVTZ. The optimized geometries and the adiabatic excitation energies of these states are in good agreement with experiments and previous calculations. The crossings and avoided crossings dis- played in the potential energy surfaces are expounded.

关键词： cross of PES, MRPT2. SO2 (sulfur dioxide).

The influence of laser pulse on the photoabsorption spectra of Li atom in strong external field

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2006年第2期49卷 178-186页

作者： WANG Dehua1 & LIN Shenglu2.1. School of physics and Electronic Engineering, Yantai Normal university, Yantai 2.402., China {2., Shandong Normal university, Jinan 2.0014, China School of physics and Electronic Engineering Yantai Normal University Yantai China department of physics Shandong Normal University Jinan China

Using the time-dependent perturbation theory and the calculation formula of the single- and double-pulse absorption spectra of the atom in strong external fields, we calculate the single- and double-pulse absorption spectra of Li atom in strong magnetic field for different pulse widths. The results show that a pulse of some width can reduce the contribution of the short period closed orbits and eliminate the contribution of the long period orbits. Compared with the single-pulse absorption spectra, we found that for some phase differences, the double-pulse laser absorption spectra are strengthened; while for others, they are reduced. Therefore, we can use the pulse laser to control the oscillation of the absorption spectra and obtain the optimization object.

关键词： laser pulse closed orbit absorption spectra.

Direct CP violation in hadronic B decays

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2006年第3期49卷 357-366页

作者： HONG Bihai1,2.& Lü Caidian3 1. department of physics, Lishui{2., Lishui 32.000,China 2. department of physics, Shanghai Jiaotong{2., Shanghai 2.0030, China 3. Institute of High Energy physics, Beijing 100049,China department of physics Lishui University Lishui China department of physics Shanghai Jiaotong University Shanghai China Institute of High Energy physics Beijing China

There are different approaches for the hadronic B decay calculations, recently. In this paper, we upgrade three of them, namely factorization, QCD factorization and the perturbative QCD approach based on kT factorization, using new parameters and full wave functions. Although they get similar results for many of the branching ratios, the direct CP asymmetries predicted by them are different, which can be tested by recent experimental measurements of B factories.

关键词： CP violation hadronic B decay factorization.

Stochastic resonance in surface catalytic oxidation of carbon monoxide induced by colored noise

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2004年第2期47卷 106-112页

作者： GONG Yubing1,2. HOU Zhonghuai1 & XIN Houwen1 1. department of Chemical physics,{2. of Science and Technology of China, Hefei 2.002., China 2. department of physics, Yantai Teachers{2., Yantai 2.402., China department of Chemical physics University of Science and Technology of China Hefei China department of physics Yantai Teachers University Yantai China

The dynamical behavior of surface catalytic oxidation reaction of Pt(110)/CO+O2.modulated by colored noise, under the condition of specific temperature, has been investigated when the partial pressure of CO gas is near the supercritical Hopf bifurcation point. By computer simulation the oscillation and stochastic resonance induced by colored noise are observed. The influences of the intensity and correlation time of colored noise on stochastic resonance are discussed. The range of sensitivity of the system to the environmental fluctuation is analyzed.

关键词： colored noise, stochastic resonance, surface catalytic reaction of Pt(110)/CO+O2. supercritical Hopf bifurcation, signal-to-noise ratio (SNR).