Plasmonic waveguides mediated energy transfer between two distant quantum dots

We investigate theoretically the radiative energy transfer between two distant quantum dots (QDs) mediated by the guided modes of Ag nanowire. The cross decay rate between the two quantum dots is derived with Markov approximation and the decay behaviors of the superradiant state and the subradiant state of quantum dots are exhibited. Due to the interference of the radiation emitted by the two QDs, the cross decay rate, the decay rates of the superradiant state, and the subradiant state show oscillation behaviors. This reveals that energy transfer from one QD to a distant QD can be controlled by adjusting the distance between the two QDs due to the periodicity of the cross decay rate.     

Electronic energy transfer between long-range resonance states of 3-mercaptopropionic acid capped CdTe quantum dots in aqueous media

We demonstrate electronic energy transfer between resonance states of 2 and 2.8?nm CdTe quantum dots in aqueous media using steady-state photoluminescence spectroscopy without using any external linker molecule. With increasing concentration of larger dots, there is subsequent quenching of luminescence in smaller dots accompanied by the enhancement of luminescence in larger dots. Our experimental evidence suggests that there is long-range resonance energy transfer among electronic excitations, specifically from the electronically confined states of the smaller dots to the higher excited states of the larger dots.     

Hypervelocity penetration modeling: momentum vs. energy and energy transfer mechanisms

Analytic penetration modeling usually relies on either a momentum balance or an energy-rate balance to predict depth of penetration by a penetrator based on initial geometry and impact velocity. In recent years, fairly sophisticated models of penetration have arisen that develop the three-dimensional flow field within a target. Based on the flow field and constitutive assumptions, it is then possible to derive a momentum or an energy-rate balance. This paper examines the use of assumed flow fields within a target created by impact and then examines the resulting predicted behavior based on either momentum conservation or energy conservation. It is shown that for the energy-rate balance to work, the details of the energy transfer mechanisms must be included in the model. In particular, how the projectile energy is initially transferred into target kinetic energy and elastic compression energy must be included. As impact velocity increases, more and more energy during the penetration event is temporarily deposited within the target as elastic compression and target kinetic energy. This energy will be dissipated by the target at a later time, but at the time of penetration it is this transfer of energy that defines the forces acting on the projectile. Thus, for an energy rate balance approach to successfully model penetration, it must include the transfer of energy into kinetic energy within the target and the storage of energy by elastic compression. Understanding the role of energy dissipation in the target clarifies the various terms in analytic models and identifies their origin in terms of the fundamental physics. Understanding the modes of energy transfer also assists in understanding the hypervelocity result that penetration depth only slowly increases with increasing velocity even though the kinetic energy increases as the square of the velocity.     

光子带隙调制下发光体间的能量传递过程

光子晶体具有光子带隙和光子局域等特有性质,光物理过程在光子带隙调制下产生新的现象特点为制备新型光电材料提供了可能。通过对光子带隙调制作用的机理探讨,设计制备蛋白石及反蛋白石结构光子晶体。对其中发光体的荧光光谱和给体荧光寿命的实验研究表明,当光子带隙频段与能量传递过程中给体的发射光谱相重叠,能量传递过程将得到增强。     

Distance-dependent energy transfer between indole and anthracene moieties in Langmuir–Blodgett films

1,2-Diphenyl indole (DPI) and 9,10-diphenyl anthracene (DPA) are non-amphiphilic molecules but form excellent LB films when mixed with stearic acid (SA). Spectroscopic investigations of these films indicate formation of aggregates of DPI and DPA in the mixed LB films. DPA has been used as the quencher of the fluorescence of the DPI donor. Distance-dependent energy transfer between donor and acceptor monolayers in the LB film, where they can be precisely separated by inert spacers of stearic acid layers of varied thickness, is shown to satisfy Khun's quadratic equation. This suggests that the donor excitations are delocalized. The large critical transfer distance estimated from the experimental results has been attributed to the formation of aggregates of the molecules in a LB monolayer.     

医用内窥镜光能传递效率的评价方法

建立医用硬性内窥镜光能传递效率的评价方法.通过影响光能传递效率的原因分析并结合光能传递效率的实际应用意义,提出了有效光度率定义和表达式,以表示医用硬性内窥镜的光能传递效率.运用光度学原理导出有效光度率测量的应用公式,并通过对相关的模拟视场面与光度量关系的理论推导,得出有效光度率测量的应用公式与模拟视场形状无关的结果,并进一步采用几个典型视场面下的实际测量,验证了该应用公式的通用性.此方法可用于医用硬性内窥镜光能传递效率的评价,便于实际测量应用.     

非线性耦合振子间的靶能量传递研究:保守系统中的完全能量传递

研究了两自由度非线性耦合振子间的靶能量传递现象。第一部分基于非线性耦合振子内在保守系统的慢变动力学方程,推导出了该结构的保守系统中两振子间完全能量传递所需要的条件。经数值仿真验证,本部分所推导的方程可准确计算两振子间完全能量传递所需的初始能量,并适用于强非线性系统。     

Optical protocol for quantum state sharing of superposed coherent state

We propose an optical protocol for quantum state sharing of superposed coherent state in terms optical elements. Our protocol can realize a near-complete quantum state sharing of a superposed coherent state with arbitrary coeficients. The realization of this protocol is appealing due to the fact that the quantum state of light is robust against the decoherence and photons are ideal carriers for transmitting quantum information over long distances. This protocol can also be generalized to the multiparty system.     

可控震源振动器平板-大地接触性质与能量传递研究

大地的表面形貌是影响可控震源振动器平板与大地之间接触性质的因素之一。为了掌握大地表面参数对可控震源振动器平板-大地接触系统接触性质及振动特性的影响规律，基于分形理论建立了三维粗糙大地表面形貌，构建了振动器平板-大地接触模型，得到了不同大地表面形貌及材料参数下振动器平板与大地之间的接触力-变形曲线；建立了振动器平板-大地接触振动动力学方程，并计算了振动器平板的位移响应以及能量传递。结果表明：振动器平板与大地之间接触力的非线性随大地表面粗糙度的增大而增大，振动器平板-大地接触系统的固有频率随大地表面粗糙度的增大而减小；粗糙表面的接触模型中振动器平板每一周期向大地传递的能量随时间的增大而减小。同时，大地表面材料参数的非线性也会影响平板-大地接触系统的振动响应和能量传递。由此可知，大地表面的粗糙度和材料的非线性是限制可控震源高频输出的重要原因。研究结果将为可控震源的优化和高频拓展提供参考。     

Gd3+-Tb3+能量转移与Tb3+自敏化效应对重金属锗酸盐玻璃发光性能的影响

研究了一组Tb^3 掺杂重金属锗酸盐玻璃的发光特性。玻璃样品的X射线激发发射光谱结果显示,玻璃基质中由Gd^3 离子向发光中心Tb^3 的能量转移机制以及在一定浓度范围内Tb^3 之间的交叉弛豫过程对玻璃的发光性能有重要影响。前者表现在Gd^3 紫外发射光的减弱及Tb^3 绿发射光的增强,后者则显示Tb^3 在一定浓度范围内所特有的自敏化效应,使其蓝发射光减弱、绿发射光增强。第3种稀土离子La^3 的引入对发光中心Tb^3 离子具有分离效应,使Tb^3 之间的交叉弛豫概率降低,蓝发射光增强。     

弦月形通道在太阳能空调系统中的强化传热研究

研究表明,弦月形通道的特殊结构可以有效促进Li—Br溶液的沸腾,降低溶液过热度,强化传热、传质过程,相同工况下的换热量是环形通道的2～3倍,使太阳能小型溴化铿吸收式空调系统在70～80℃宅加热水温度下就可以正常运行。弦月形通道偏心特性尺寸S对通道内Li-Br溶液的流动与换热影响很大,实验结果表明：di＝19mm和do＝32mm的铜管构成的弦月形通道的提升效果较好。     

Spectral and laser studies on energy transfer binary dye-doped polymer laser rods

The energy transfer mechanism of two different dyes, C450 as donor and C535 as acceptor incorporated into polymeric matrices, is investigated. The absorption and fluorescence characteristics of C450 and C535 dye-doped polymer modified with ethanol are studied. The results are compared with their respective liquid mixtures. The spectral parameters of C450 and C535 in polymer and the corresponding monomer compositions are obtained. We study the variation of gain for different acceptor concentrations whilst keeping the donor concentration fixed. The gain of acceptor with donor increased and then decreased as the acceptor concentration was increased. Both solid and liquid media showed similar trends. We also study the photobleaching of the dye-doped polymer rod under nitrogen laser excitation.     

The using of LS-DYNA for the simulation of heat transfer in explosives

The using of FEM and especially LS-DYNA3D code for the simulation of a heat transfer during the heating of the explosive charge is discussed in this paper. The characterization of explosive material properties (density, thermal conductivity, specific heat, heat of decomposition, the decomposition kinetics) is described. LS-DYNA3D code is used for the fitting of the appropriate kinetic model and for the simulation of the heat transfer during the slow cookoff test. The results of simulations are compared to the experimental values for the SEMTEX 1A plastic bonded explosive.     

二维层状WS2/MoS2异质结中镧系近红外光子发射与能量转移（英文）

镧系离子由于其独特的光子特性而备受关注.二维层状范德华异质结的光电特性和器件性能受到界面耦合的极大影响,该异质结通常是由两层或多层过渡金属二硫化物(TMD)堆叠而成.本文通过两步合成构建了镧系离子掺杂的层状WS2/MoS2异质结.所制备的掺杂薄膜是在晶圆衬底上生长的高度织构纳米片.更重要的是,由于两个TMD层中镧系离子之间的能量转移,层状异质结的结构减少了因均匀掺杂或浓度猝灭而引起的无益交叉松弛,所制备的堆叠异质结能够在近红外通讯窗口产生高效的光子发射.镧系掺杂和能量转移的研究结果表明,镧系离子可以有效地扩展TMD薄膜的发射波段及其异质结构.本工作所发展的镧系掺杂TMD异质结有助于进一步研究原子级超薄近红外光子器件.     

The elastic strain energy of a coherent inclusion with deviatoric misfit strains

The elastic strain energy of a misfitted coherent inclusion is discussed using the Eshelby method for ellipsoidal inclusions. Deviatoric and tetragonal misfit strains in an elastically inhomogeneous spheroidal inclusion are particularly considered. The variation of the elastic strain energy is evaluated as a function of the shape and orientation of the inclusion. Results obtained are compared with those for a coherent inclusion with purely dilatational misfit strains. Under certain deviatoric misfit strains and elastic moduli of the inclusion, the least elastic strain energy is achieved by a spheroid with an intermediate shape between a plate and a sphere or between a sphere and a needle.     

Understanding excitation energy transfer in metalloporphyrin heterodimers with different linkers,bonding structures,and geometries through stimulated X-ray Raman spectroscopy

We present simulations of stimulated X-ray Raman (SXRS) signals from covalently bonded porphyrin heterodimers with different linkers, chemical bonding structures, and geometries. The signals are interpreted in terms of valence electron wavepacket motion. One- and two-color SXRS signals can both mark excitation energy transfer (EET) between the porphyrin monomers. It is shown that the SXRS signals provide a novel window into EET dynamics in multiporphyrin systems, and can be used as a powerful tool to monitor the subtle chemical environment which affects EET.     

L型耦合板相关激励下高频随机能量流分析

将板的能量流分析法应用于耦合板结构受随机激励的情形,并用无限板导纳近似有限板导纳的方法考虑了随机力的相关性对输入功率的影响。对在同一块板上受到两个相关或不相关随机力作用的L型耦合板的能量响应和功率流进行了计算,结果反映了能量密度的空间分布和功率在子结构间和内部的传递路径。两种相关激励条件下的结果对比表明,作用于所考虑位置上的随机激励间的相关性对耦合结构的能量响应及功率传递的影响很小。对该L型耦合板的响应用传统的统计能量分析法进行了求解,其结果与能量流分析法预测的主要能量场的响应基本一致,说明了考虑随机力间相关作用的能量流分析法应用的有效性。