N巴黎势和可能的p共振态(英文)

通过求解N巴黎光学势的复薛定谔方程,研究了N系统的近阈束缚和共振行为,得到了一个p系统的13P0共振态.发现其能量和宽度与最近BES用Breit Wigner(B W)公式分析J/ψ→γp衰变的实验数据给出的结果相容.讨论了这一结果的含义及进一步研究的建议.     

Physiochemical and cytotoxicity study of TPGS stabilized nanoemulsion designed by ultrasonication method

The main aim of the present work was to prepare TPGS stabilized D-α-Tocopherol, lemon oil, tween-80, and water nanoemulsion by low cost and highly effective sonication method. The prepared nanoemulsion showed good stability for 60 days at variable temperature conditions i.e. 4, 25 and 37 °C. The tolerance of the prepared nanoemulsion to salt (50 mM–500 mM) and pH (pH 2–pH 7.4) was also studied. The morphology and droplet size of pure and quinine loaded nanoemulsion was characterized with transmission electron microscopy. The prepared formulation was transparent and the obtained average particle size ranged between 25 nm and 35 nm. The nanoemulsion was found to be non toxic. The cell viability study of pure nanoemulsion carried out on Hep G2 cells revealed that the cell viability was 100%. The formulation further exhibited high quinine loading and release capacity with cumulative release up to 76 ± 2% and 65 ± 2% at pH 7.4 and pH 5.5 respectively. The interaction between quinine and vitamins (riboflavin, thiamine and biotin) was also carried out (aqueous medium). The study revealed that riboflavin had strong interaction with quinine and vitamins vis-à-vis thiamine and biotin.     

Sizable band gap in organometallic topological insulator

Based on first principle calculation when Ceperley–Alder and Perdew–Burke–Ernzerh type exchange-correlation energy functional were adopted to LSDA and GGA calculation, electronic properties of organometallic honeycomb lattice as a two-dimensional topological insulator was calculated. In the presence of spin–orbit interaction bulk band gap of organometallic lattice with heavy metals such as Au, Hg, Pt and Tl atoms were investigated. Our results show that the organometallic topological insulator which is made of Mercury atom shows the wide bulk band gap of about ∼120 meV. Moreover, by fitting the conduction and valence bands to the band-structure which are produced by Density Functional Theory, spin–orbit interaction parameters were extracted. Based on calculated parameters, gapless edge states within bulk insulating gap are indeed found for finite width strip of two-dimensional organometallic topological insulators.     

Ion–laser interactions: The most complete solution

Trapped ions are considered one of the best candidates to perform quantum information processing. By interacting them with laser beams they are, somehow, easy to manipulate, which makes them an excellent choice for the production of nonclassical states of their vibrational motion, the reconstruction of quasiprobability distribution functions, the production of quantum gates, etc. However, most of these effects have been produced in the so-called low intensity regime, this is, when the Rabi frequency (laser intensity) is much smaller than the trap frequency. Because of the possibility to produce faster quantum gates in other regimes it is of importance to study this system in a more complete manner, which is the motivation for this contribution. We start by studying the way ions are trapped in Paul traps and review the basic mechanisms of trapping. Then we show how the problem may be completely solved for trapping states; i.e., we find (exact) eigenstates of the full Hamiltonian. We show how, in the low intensity regime, Jaynes–Cummings and anti-Jaynes–Cummings interactions may be obtained, without using the rotating wave approximation and analyze the medium and high intensity regimes where dispersive Hamiltonians are produced. The traditional approach (low intensity regime) is also studied and used for the generation of non-classical states of the vibrational wavefunction. In particular, we show how to add and subtract vibrational quanta to an initial state, how to produce specific superpositions of number states and how to generate NOON states for the two-dimensional vibration of the ion. It is also shown how squeezing may be measured. The time dependent problem is studied by using Lewis–Ermakov methods. We give a solution to the problem when the time dependence of the trap is considered and also analyze a specific (artificial) time dependence that produces squeezing of the initial vibrational wave function. A way to mimic the ion–laser interaction via classical optics is also introduced.     

Spin-Dependent Electron Properties of a Triple-Terminal Quantum Dot Structure

Electron transport properties of a triple-terminal Aharonov-Bohm interferometer are theoretically studied. By applying a Rashba spin-orbit coupling to a quantum dot locally, we find that remarkable spin polarization comes about in the electron transport process with tuning the structure parameters, i.e., the magnetic flux or quantum dot levels. When the quantum dot levels are aligned with the Fermi level, there only appear spin polarization in this structure by the presence of an appropriate magnetic flux. However, in absence of magnetic flux spin polarization and spin separation can be simultaneously realized with the adjustment of quantum dot levels, namely, an incident electron from one terminal can select a specific terminal to depart from the quantum dots according to its spin state.     

Noise effects in two different biological systems

We investigate the role of the colored noise in two biological systems: (i) adults of Nezara viridula (L.) (Heteroptera: Pentatomidae), and (ii) polymer translocation. In the first system we analyze, by directionality tests, the response of N. viridula individuals to subthreshold signals plus noise in their mating behaviour. The percentage of insects that react to the subthreshold signal shows a nonmonotonic behaviour, characterized by the presence of a maximum, as a function of the noise intensity. This is the signature of the non-dynamical stochastic resonance phenomenon. By using a “soft” threshold model we find that the maximum of the input-output cross correlation occurs in the same range of noise intensity values for which the behavioural activation of the insects has a maximum. Moreover this maximum value is lowered and shifted towards higher noise intensities, compared to the case of white noise. In the second biological system the noise driven translocation of short polymers in crowded solutions is analyzed. An improved version of the Rouse model for a flexible polymer is adopted to mimic the molecular dynamics by taking into account both the interactions between adjacent monomers and the effects of a Lennard-Jones potential between all beads. The polymer dynamics is simulated in a two-dimensional domain by numerically solving the Langevin equations of motion in the presence of thermal fluctuations and a colored noise source. At low temperatures or for strong colored noise intensities the translocation process of the polymer chain is delayed. At low noise intensity, as the polymer length increases, we find a nonmonotonic behaviour for the mean first translocation time of the polymer centre of inertia. We show how colored noise influences the motion of short polymers, by inducing two different regimes of translocation in the dynamics of molecule transport.     

Collisional effects on the current-filamentation instability in a dense plasma

The collisional current-filamentation instability (CFI) is studied for a nonrelativistic electron beam penetrating an infinite uniform plasma. It is analytically shown that the CFI is driven by the drift-anisotropy rather than the classical anisotropy of the beam and the background plasma. Therefore, collisional effects can either attenuate or enhance the CFI depending on the drift-anisotropy of the beam-plasma system. Numerical results are given for some typical parameters, which show that collisional effects cannot stabilize but enhance the CFI in a dense plasma. Thus, the CFI may play a dominant role in the fast electron transport and deposition relevant to the fast ignition scenario (FIS).     

正常金属-分子量子点-超导耦合系统的介观输运研究

运用非平衡格林函数理论、正则变换以及BCS平均场理论研究了正常金属-分子量子点-超导耦合系统（N-MQD-S）的介观输运,得到了系统的电流公式并选择适当的参数进行了数值计算。数值计算结果表明：电声子耦合强度 与线宽函数 对系统的输运行为有较大影响。当 增大时,由声子辅助隧穿所产生的共振峰将高于分子量子点自身能级产生的共振峰;当线宽函数 增大时,在Andreev反射共振峰的两侧将出现新的边峰。     

C波段50 MW行波输出速调管设计

设计了导流系数1.53 P的电子枪,枪内场强低于22.1 kV/mm,阴极平均负载小于6.3 A/cm2;采用部分屏蔽流均匀场电磁聚焦系统,实现了对电子注的良好聚焦;设计了C波段/2模盘荷波导行波输出结构,采用CST软件对其色散特性、耦合阻抗进行了计算分析。首先以单间隙输出腔代替行波输出结构对5腔注-波互作用系统进行计算,确定了前4腔的设计参数,然后采用PIC模拟软件对具有盘荷波导结构的输出系统进行了三维模拟,获得了大于50 MW的输出功率,效率大于45%,饱和增益大于50 dB,盘荷波导结构间隙电压比单间隙输出腔下降30%,效率提高4%。     

0.4 THz回旋行波管的设计与模拟

利用三维粒子模拟仿真软件,对共焦波导结构的0.4 THz回旋行波管进行了注波互作用的模拟研究。以共焦波导的冷腔色散以及衍射损耗入手,最终选定HE06模作为互作用工作模式。为了对寄生振荡进行抑制,在互作用结构中引入了截断。在模拟过程中,通过调节束压、束流、工作磁场、电子束横纵速度比,得到了最优的工作参数。最终,在束压34 kV、磁场14.25、束流2 A、横纵速度比0.75的工作参数下,当输入信号为1 W时,得到了最高2.76 kW的功率输出,增益超过34 dB,3 dB带宽为8 GHz,效率达到4%。