宏观交通流模型的能耗研究

本文在几种典型的宏观交通流模型的基础上,导出能量耗散的计算公式,宏观交通流模型能耗不同于元胞自动机交通模型,其能耗不仅考虑车流速度减少,而且还要计及通过路段的车流通量引起的能耗.通过对满足黎曼初始条件的道路能耗和道路交通瓶颈处能耗的计算和理论分析,表明交通拥堵处,能量耗散比较高,而且能量耗散的变化也能反映交通拥堵产生及消散的情况.     

界面摩擦过程非连续能量耗散机理研究

结合无磨损界面摩擦微观能量耗散机理的复合振子模型,运用量子理论建立了微观能量耗散的量子力学模型.分析表明：在滑动过程中,当界面原子从一种平衡态跳跃至另一种平衡态时,摩擦功以离散形式耗散为界面原子热振子,且界面吸收能量的能力是离散的;高能态界面较低能态界面吸收能量的能力强,表现为易于吸收界面势能.界面原子吸收和释放能量的离散性在宏观上表现为摩擦功耗散的非连续性,为从微观角度解释无磨损界面摩擦状态周期性变化提供了理论基础. 关键词： 摩擦 非连续能量耗散 复合振子模型     

The potential energy function of the nitrous oxide molecule using pure vibrational data

Using a very large and partly new set of vibrational data, a preliminary determination of the potential energy function of the nitrous oxide molecule has been undertaken and the results are presented in this paper. These results are discussed.     

棒板耦合结构的振动能量传输研究

本文以棒、板耦合结构为例,从理论和实验上证明和验证了统计能量方法对强耦合结构仍然适用;进而又对该结构的耦合损耗因子进行了较为详细的计算和讨论,并与弱耦合条件下的统计能量方法结果进行了比较,得出了该方法适用的条件以及在低模态密度情况下耦合损耗因子的表示式;最后通过大量实验对所得结论进行了验证,结果是令人满意的。     

The vibrational energy levels of ammonia

A variational 6-dimensional method is used to determine the low lying vibrational energy levels of ammonia. The six internal coordinates were chosen to be appropriate for the symmetry and inversion motion of the molecule; they were the three NH bond lengths, r1, r2, r3, the unique angle β which each bond makes with the trisector of them, and two (of the three) angles, θ2 and θ3, between the bonds when projected on to a plane perpendicular to the trisector. The Wilson G matrix was determined for these internal coordinates both by computer algebra and by hand. An appropriate Jacobian for the motion was determined and the full Hermitian kinetic energy operator was obtained using the Podolsky transformation. Expansion functions were in the usual product form. Special attention was given to the θ2, θ3 expansion functions so that appropriate A1, A2 and E symmetry vibrational modes were obtained explicitly. Matrix elements of the kinetic energy operator were expressed in terms of one-dimensional integrals.Variational calculations have been performed with two six-dimensional surfaces: (i) that due to Martin, Lee and Taylor; and (ii) that due to Spirko and Kraemer. Although some of the vibrational levels for both surfaces are accurate, both have inadequacies: (a) because it is a Taylor expansion about an equilibrium, based on ab initio calculations, with no attention paid to planarity; and (b) because the non-inversion part of the surface was treated perturbatively in its derivation, and in fact some of the quartic displacement powers have negative coefficients. Therefore, neither surface gave good results overall, and there is a need for a refined 6 dimensional NH3 surface.     

Reduction of pulse-to-pulse fluctuation in laser pulse energy using the optical Kerr effect

An all-optical stabilization method of laser pulse energy is proposed using the optical Kerr effect (OKE). The method uses the OKE induced by a portion of the laser pulse as a power controller. The decrease (increase) in the throughput of the optical setup for OKE compensates for the increase (decrease) in pulse energy, thereby stabilizing the pulse-to-pulse fluctuation in pulse energy. The validity of this principle was proven by experiments with a femtosecond laser.     

Effects of energy dissipation on anisotropic materials

A model and its simulations are presented to describe the effects of energy dissipation on anisotropic systems. When the current electromigration is constant, energy dissipation depends on lattice constants, resistivity, and the angles along the longitudinal and transversal directions. It is shown that an orientation variation of the grain can significantly influence the energy dissipation for some anisotropic materials. Based on calculations for the grain model, the mechanism of grain growth and microstructure evolution under electromigration is explained. Theoretical implications about material selection and reliability are derived.     

Uncertainty principle and minimal energy dissipation in the computer

Reversible computation is briefly reviewed, utilizing a refined version of the Bennett-Fredkin-Turing machine, invoked in an earlier paper. A dissipationless classical version of this machine, which has no internal frietion, and where the computational velocity is determined by the initial kinetic energy, is also described. Such a machine requires perfect parts and also requires the unrealisstic assumption that the many extraneous degrees of freedom, which contribute to the physical structure, do not couple to the information-bearing degrees of freedom, and thus cause no friction Quantum mechanical computation is discussed at two levels. First of all we deplore the assertion. repcatedly found in the literature, that the uncertainty principle. Eth, with t equated to a switching time, yields any information about energydissipation. Similarly we point out that computation is not an iterated transmission and receiving process, and that considerations, which avoid the uncertainty principle, and instead use quantum mechanical channel capacity considerations, are equally unfounded. At a more constructive level we ask whether there is a quantum mechanical version of the dissipationless computer. Benioff has proposed one possible answer Quantum mechanical versions of dissipationless computers may suffer from the problems found in electron transport in disordered one-dimensional periodic potentials. The buildup of internal reflections may give a transmission coefficient. through the whole computation, which decreases exponentially with the length of the computation.     

Laser pulse design using optimal control theory-based adaptive simulated annealing technique: vibrational transitions and photo-dissociation

We have designed and optimised a combined laser pulse using optimal control theory-based adaptive simulated annealing technique for selective vibrational excitations and photo-dissociation. Since proper choice of pulses for specific excitation and dissociation phenomena is very difficult, we have designed a linearly combined pulse for such processes and optimised the different parameters involved in those pulses so that we can get an efficient combined pulse. The technique makes us free from choosing any arbitrary type of pulses and makes a ground to check their suitability. We have also emphasised on how we can improve the performance of simulated annealing technique by introducing an adaptive step length of the different variables during the optimisation processes. We have also pointed out on how we can choose the initial temperature for the optimisation process by introducing heating/cooling step to reduce the annealing steps so that the method becomes cost effective.     

用代数能量方法研究氢化物双原子分子的完全振动能谱和离解能

本文用研究双原子分子振动能谱的新方法-代数方法(AM),研究了KH-X1Σ+,RbH-X1Σ+,DF-X1Σ+和DCl-X1Σ+等四个氢化物双原子分子的电子基态的振动光谱常数和振动能谱;用代数能量方法(AEM)研究了相应电子态的分子离解能.研究结果表明:使用实验获得的少数精确的振动能级[Eυ],由AM方法得到的振动能谱不仅能够重复这些电子态的已知实验能级,还能够得到用现代实验方法或精确的量子理论方法很难得到的所有高振动激发态的能级.由AEM方法能够得到比用文献发表的振动光谱常数计算获得的离解能值更准确的分子离解能.     

On the energy dissipation in a convective well-mixed layer

Summary Energy dissipation in a convective atmospheric mixed layer and its parametrization are discussed. A formulation of energy dissipation based on the results of Zeman and Tennekes and Kitaigoroskii is proposed.

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Riassunto In questo lavoro si discutono il ruolo e la parametrizzazione dell'energia dissipata nei moti convettivi che generano lo strato rimescolato in atmosfera. Si propone una possibile parametrizzazione basata sui precedenti lavori di Kitaigoroskii e di Zeman e Tennekes.

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Резюме Обсуждается диссипация энергии в конвективном атмосферном перемешанном слое и параметризация диссипации. Предлагается формулировка диссипации энергии, основанная на результатах Земана и Тенекеса (1976) и Китайгородского (1978).

     

Surveying the role of excitation energy in probing nuclear dissipation

A dynamical Langevin model is employed to calculate the excess of the evaporation residue cross sections of the ^194Pb nucleus over that predicted by the standard statistical model as a function of nuclear dissipation strength. It is shown that large excitation energy can increase the effects of nuclear dissipation on the excess of the evaporation residues and the sensitivity of this excess to the dissipation strength,and that more higher excitation energies have little contribution to further raising this sensitivity. These results suggest that on the experimental side,producing those compound systems with moderate excitation energy is sucient for a good determination of the pre-saddle nuclear dissipation strength by measuring the evaporation residue cross section,and that forming an extremely highly excited system does not considerably improve the sensitivity of evaporation residues to the dissipation strength.     

摩擦微观能量耗散机理的复合振子模型研究

提出无磨损界面摩擦微观能量耗散机理的复合振子模型，指出滑动摩擦过程同时存在整体做低频弹性振动的宏观振子和界面原子受激励产生热振动的微观振子，并在此基础上分析了宏观振子和微观振子对摩擦能量耗散的不同影响. 通过对界面原子的动力学分析，指出摩擦过程界面激励力的频率是能量转换的关键:在平衡力作用阶段，界面作用力的频率趋于零，因而可以直接作用到每个原子，力的作用效果是整体和均匀的；在失稳跳跃阶段,由于界面激励力的频率极高，造成摩擦界面原子获得的能量分布很不均匀，从而产生不可逆的能量耗散过程. 与目前通用的独立振子模型比较，复合振子模型能够更准确描述摩擦能量耗散过程，可为摩擦控制提供理论指导. 关键词： 摩擦 能量耗散机理 复合振子模型 独立振子模型     

Measurement of vibrational energy flow in a plate with high energy flow boundary crossing using electronic speckle pattern interferometry

The measurement of vibrational energy flow is an important tool in understanding the vibrational behaviour of structures. In the past, because of transducer constraints, the measurement of vibrational energy flow was mostly restricted to single point measurements. However, recent developments in advanced laser measurement techniques, such as electronic speckle pattern interferometry (ESPI), have gained interest in applying two-dimensional, multi-point measurement techniques to the estimation of vibrational energy flow. This paper addresses the measurement of vibrational energy flow in a plate by using an ESPI based vibrational energy flow measurement technique. A radially symmetric bending wave plate vibration model is introduced and theoretical expressions for energy-based quantities are derived. To assess the accuracy of the measurement method, these theoretical quantities are compared to synthetic results derived from the ESPI energy flow measurement technique. The ESPI measurement technique is also applied to an experimental ‘infinite’ plate. Thus, a specially designed experimental apparatus was constructed so as to minimise undesired wave reflections in the plate and, thus, achieve a high energy flow boundary crossing at the edges of the plate. To reduce the effect of optical noise contamination on the ESPI measured out-of-plane plate displacement data, optimal filters were applied prior to the vibrational energy flow computation. To appraise the accuracy of the experimental method, measured vibrational power on the plate is compared with measured vibrational input power. A difference of less than 1 dB between both quantities indicates that vibrational energy flow within a rectangular plate that contains radially symmetric wave propagation can be measured to a good degree of accuracy if appropriate filtering is applied.     

Surveying the role of excitation energy in probing nuclear dissipation

A dynamical Langevin model is employed to calculate the excess of the evaporation residue cross sections of the 194pb nucleus over that predicted by the standard statistical model as a function of nuclear dissipation strength. It is shown that large excitation energy can increase the effects of nuclear dissipation on the excess of the evaporation residues and the sensitivity of this excess to the dissipation strength, and that more higher excitation energies have little contribution to further raising this sensitivity. These results suggest that on the experimental side, producing those compound systems with moderate excitation energy is sufficient for a good determination of the pre-saddle nuclear dissipation strength by measuring the evaporation residue cross section, and that forming an extremely highly excited system does not considerably improve the sensitivity of evaporation residues to the dissipation strength.