张量耦合在改进的标量微分耦合模型中的作用

研究了改进的标量微分耦合模型中,ω介子与核子张量耦合对于有限核计算的影响.张量耦合改善了标量微分耦合模型中有限核的自旋与轨道分裂;同时该张量耦合在核的中心区域表现为吸引作用,在核的表面区域表现为排斥作用,这一结果导致有限核填充在很低单粒子轨道的一些核子的能量因张量耦合而增大,填充在靠近费密面轨道的一些核子的能量因张量耦合而减小.     

Relations Between Helicity Coupling Amplitude and L—S Coupling Amplitude

Relations between helicity coupling amplitude and L-S coupling amplitude are discussed.The equivalence condition for these two kinematic analysis methods and the limitations of the L-S coupling amplitude are also studied in this paper.     

夸克-介子耦合模型

对夸克-介子耦合模型的研究进展及现状进行了简述.在此基础上,利用非拓扑孤子袋模型的思想和改进的夸克质量密度相关(IQMDD)模型,考虑夸克之间的排斥作用而加入ω介子,称为IQMDD-Ⅰ模型,得到了基态波函数和介子场满足的方程.利用平均场近似方法,通过得到的基态夸克波函数计算了核子的均方根半径和磁矩等可观测量,其结果与实验值吻合得较好.     

Coupling parameter trajectories

Results are presented about singular surfaces of Green's functions in the complex manifold (g², t) of the coupling parameter g² and a dynamical variable t.     

Controlling Entanglement Dynamics by Choosing Appropriate Ratio betweenCavity-Fiber Coupling and Atom-Cavity Coupling

The entanglement characteristics including the so-called sudden death effectbetween two identical two-level atoms trapped in two separate cavitiesconnected by an optical fiber are studied. The results show that the timeevolution of entanglement is sensitive not only to the degree ofentanglement of the initial state but also to the ratio between cavity-fibercoupling (v) and atom-cavity coupling (g). This means that theentanglement dynamics can be controlled by choosing specific v and g.     

Coupling gravitons to matter

Using relationships between open and closed strings, we present a construction of tree-level scattering amplitudes for gravitons minimally coupled to matter in terms of gauge theory partial amplitudes. In particular, we present examples of amplitudes with gravitons coupled to vectors or to a single fermion pair. We also present two examples with massive graviton exchange, as would arise in the presence of large compact dimensions. The gauge charges are represented by flavors of dynamical scalars or fermions. This also leads to an unconventional decomposition of color and kinematics in gauge theories.     

Interchain Coupling in Polydiacelene

Interchain coupling in polydiacetylene is investigated by considering two parallel chains and taking into account a hopping of π electrorls from one chain to the other. The correction in energy and the change of polaronic bioding energy resulting from interchain coupling are calculated by using Green's function, and the results are compared with experimental data.     

On the Spin-Rotation-Gravity Coupling

The inertial and gravitational properties ofintrinsic spin are discussed and some of the recent workin this area is briefly reviewed. The extension ofrelativistic wave equations to accelerated systems and gravitational fields is criticallyexamined. A nonlocal theory of accelerated observers ispresented and its predictions are compared withobservation.     

Coupling of quantum logics

A quantum logic is a couple (L, M), whereL is a logic andM is a quite full set of states onL. A tensor product in the category of quantum logics is defined and a comparison with the definition of free orthodistributive product of orthomodular σ lattices is given. Several physically important cases are treated.     

Coupling plasmons and dyakonons

We study the coupling of plasmons and Dyakonov surface waves propagating at the interfaces between isotropic-birefringent-metal layered structures. Efficient coupling is shown to occur with a proper choice of the crystal birefringence, the refractive index of the isotropic medium, and the light propagation direction relative to the crystal optical axis. In the case of low-loss metals, coupling efficiencies as high as 90% are predicted to be possible.     

在量子色动力学中坡密子与核子的耦合

用强相互作用的基本理论量子色动力学推导出了坡密子与核子的耦合顶点, 得到了在绕射过程的研究中广泛应用的, 耦合强度,β=6.0GeV^—1,的经验的耦合顶点,βγ^μF¹(t). 本研究也清楚地表明了坡密子的胶子起源和胶子球的粒子性本质, 这是一个长期没有解决的问题. 结合我们以前的研究结果, 我们认为坡密子可能是一个在雷其轨迹,α(t)=1.08+0.20GeV^－2t,上, 具有量子数,I^G J^PC = 0⁺2⁺⁺,的雷其化的张量胶子球. 所以在雷其轨迹没有物理粒子的困难似乎得到了解决.     

Forward-Backward Coupling in Superfluorescence

It is shown that — within the framework of an idealized model with taking into account backscattering at density fluctuations — there is a number N_K of atoms such that for an atomic number N ? N_K forward-backward independence will be found while N ? N_K leads to synchronized superfluorescence pulses in both directions.     

大容差光纤耦合技术研究

设计了一种新型的耦合系统,该耦合系统由大口径聚焦透镜、1/4节距自聚焦透镜、锥形光纤和球端光纤四部分组成.分析了自聚焦透镜压缩发散角和球端光纤增大数值孔径的机理,给出了计算锥形光纤参量的详细流程.采用大口径透镜和1/4节距自聚焦透镜有效增大径向位置容差和角度容差,然后通过锥形光纤压缩光束半径将激光耦合进球端光纤.仿真实验结果表明,该系统耦合在r<3 mm,－1<θ<1.5范围内的耦合效率稳定保持在50%以上.     

波导与探测器吸收层垂直耦合结构中的光学耦合分析

利用几何学理论分析了波导与探测器吸收层之间的光学传播情况，以硅基波导与ＧｅＳｉ／Ｓｉ多量子阱ＰＩＮ探测器吸收层主分析对象，说明光学耦合效率与两层介质的折射率分布及吸收层长度的关系。     

The Effect of Spin-Orbit Coupling and Spin-Spin Coupling of Compact Binaries on Chaos

There are spin-orbit interaction and spin-spin interaction in a generic post-Newtonian Lagrangian formulation of comparable mass spinning compact binaries. The spin-orbit coupling or the spin-spin coupling plays a quite important role in changing the evolution of the system and may sometime cause chaotic behavior. How do the two types of couplings exert together any influences on chaos in this formulation? To answer it, we simply take the Lagrangian formulation of a special binary system, including the Newtonian term and the leading-order spin-orbit and spin-spin couplings. The key to this question can be found from a Hamiltonian formulation that is completely identical to the Lagrangian formulation. If the Lagrangian does not include the spin-spin coupling, its equivalent Hamiltonian has an additional term(i.e. the next-order spin-spin coupling) as well as those terms of the Lagrangian. The spin-spin coupling rather than the spin-orbit coupling makes the Hamiltonian typically nonintegrable and probably chaotic when two objects spin. When the leading-order spin-spin coupling is also added to the Lagrangian, it still appears in the Hamiltonian.In this sense, the total Hamiltonian contains the leading-order spin-spin coupling and the next-order spin-spin coupling,which have different signs. Therefore, the chaos resulting from the spin-spin interaction in the Legrangian formulations is somewhat weakened by the spin-orbit coupling.     

Controlling Entanglement Dynamics by Choosing Appropriate Ratio between Cavity-Fiber Coupling and Atom-Cavity Coupling

The entanglement characteristics including the so-called sudden death effect between two identical twolevel atoms trapped in two separate cavities connected by an optical fiber are studied. The results show that the time evolution of entanglement is sensitive not only to the degree of entanglement of the initial state but also to the ratio between cavity-fiber coupling （v） and atom-cavity coupling （g）. This means that the entanglement dynamics can be controlled by choosing specific v and ft.     

The Effect of Spin-Orbit Coupling and Spin-Spin Coupling of Compact Binaries on Chaos

There are spin-orbit interaction and spin-spin interaction in a generic post-Newtonian Lagrangian formu-lation of comparable mass spinning compact binaries. The spin-orbit coupling or the spin-spin coupling plays a quite important role in changing the evolution of the system and may sometime cause chaotic behavior. How do the two types of couplings exert together any influences on chaos in this formulation? To answer it, we simply take the Lagrangian formulation of a special binary system, including the Newtonian term and the leading-order spin-orbit and spin-spin couplings. The key to this question can be found from a Hamiltonian formulation that is completely identical to the Lagrangian formulation. If the Lagrangian does not include the spin-spin coupling, its equivalent Hamiltonian has an additional term (i.e. the next-order spin-spin coupling) as well as those terms of the Lagrangian. The spin-spin coupling rather than the spin-orbit coupling makes the Hamiltonian typically nonintegrable and probably chaotic when two objects spin. When the leading-order spin-spin coupling is also added to the Lagrangian, it still appears in the Hamiltonian. In this sense, the total Hamiltonian contains the leading-order spin-spin coupling and the next-order spin-spin coupling, which have different signs. Therefore, the chaos resulting from the spin-spin interaction in the Legrangian formulations is somewhat weakened by the spin-orbit coupling.     

多线阵半导体激光器的单光纤耦合输出

设计并研制了一种多线阵半导体激光器的高亮度光纤耦合输出模块.激光器芯片采用了分子束外延方法生长的宽波导、双量子阱结构AlGaAs/GaAs激光器外延材料,激光器模块采用6只准直的线阵半导体激光器,器件腔长为1.2 mm,单个发光单元宽度为100 μm,发光单元周期为500 μm,单线阵器件包括19个发光单元,单线阵器件的连续输出功率为50 W,每只单线阵器件的准直输出光束经过空间合束后再通过光束对称化变换实现了多线阵器件输出的高光束质量功率合成,采用平凸柱透镜实现了合束光束与400 μm芯径、数值孔径0.22石英光纤的高效率耦合,整体耦合效率达到65%,最大耦合输出功率达到195 W,光纤端面功率密度达到1.55×105 W/cm2.     

Coupling mechanism of an EMAT

Electro-magnetic acoustic transducers (EMATs) generate ultrasonic waves in metals through an electromagnetic coupling mechanism. A concept for EMAT generation, using a coil alone without a permanent magnet, but with a pulse generator and a sample, is introduced. A simplified equivalent coil circuit is given, and has been validated by experimental measurements. Such an equivalent circuit is useful for excitation current calculations, which have often been neglected in previous publications in this area but have proved to be of great importance in considering the efficiency and frequency characteristics of ultrasonic generation. Due to the coil sample coupling, the equivalent coil inductance is dependent on the electrical conductivity and magnetic permeability of the metal sample, the lift-off, the coil orientation relative to the metal sample and the coil configuration. The use of a coil alone to generate ultrasound has limited applications as a suitable ultrasonic detector must also be used, but where appropriate this type of generation source provides a robust, non-contact and inexpensive means of ultrasonic generation without worrying the permanent magnet attracting ferromagnetic particles that can prevent from practical on-line application of EMATs.