Effects of drive imbalance on the particle emission from a Bose–Einstein condensate in a one-dimensional lattice

Time-periodic driving has been an effective tool in the field of nonequilibrium quantum dynamics, which enables precise control of the particle interactions. We investigate the collective emission of particles from a Bose–Einstein condensate in a one-dimensional lattice with periodic drives that are separate in modulation amplitudes and relative phases. In addition to the enhancement of particle emission, we find that amplitude imbalances lead to energy shift and band broadening,while typical re...     

放射形专用线非直达车流取送方案研究

放射形专用线非直达车流取送问题是一个复杂的组合优化问题,一个最佳的取送顺序会在最大程度上缩短车流在站非生产时间,加速车辆周转。文中根据非直达车流的特点,优化了初始解的产生,以简化的在站停留时间最短为适应度函数,将取送顺序作为一个整体,设计了禁忌搜索算法。结合实例计算,结果表明该算法在求解非直达车流取送问题上取得了较满意的解。     

Selection rules for electric multipole transition of triatomic molecule in scattering experiments

In the electron or x-ray scattering experiment,the measured spectra at larger momentum transfer are dominated by the electric dipole-forbidden transitions,while the corresponding selection rules for triatomic molecules have not been clearly elucidated.In this work,based on the molecular point group,the selection rules for the electric multipolarities of the electronic transitions of triatomic molecules are derived and summarized into several tables with the variation of molecular geometry in the transition process being considered.Based on the summarized selection rules,the electron energy loss spectra of H_2O,CO_2,and N_2O are identified,and the momentum transfer dependence behaviors of their valence-shell excitations are explained.     

正十一烷/空气在宽温度范围下着火延迟的激波管研究

在加热激波管上测量了气相正十一烷/空气混合物的着火延迟时间,着火温度为宽温度范围731-1399 K,着火压力在2.02 × 10⁵和10.10 × 10⁵ Pa附近,化学计量比分别为0.5、1.0和2.0。通过监测管侧壁观测点处的反射激波压力和OH^*发射光测出着火延迟时间。实验结果显示：在910 K以上,着火延迟时间随着火温度的降低而变长,从910到780 K,着火延迟时间随着火温度的降低而变短（显示出了负温度系数效应）,在780 K以下,着火延迟时间随着火温度的降低再次变长。在所研究的压力下,着火压力的增加使着火时间变短。化学计量比对着火延迟的影响在着火压力为2.02 × 10⁵和10.10 × 10⁵ Pa时是不同的,与在高温区相比,着火延迟在低温区对化学计量比非常敏感。在整个温度范围内,当前实验结果和LLNL（LawrenceLivermore National Laboratory）机理的预测值表现出了很好的一致性。现在的正十一烷/空气的着火数据和先前实验测量的正庚烷/空气、正癸烷/空气和正十二烷/空气的着火延迟时间相比较显示了着火延迟时间随着直链烷碳原子数的增加而减小。敏感度分析显示,高、低温条件下影响正十一烷着火延迟过程的反应是显著不同的。在高温条件下起最大促进作用的反应是H + O₂=O+OH,然而在低温条件下,起最大促进作用的反应是过氧十一烷基（C₁₁H₂₃O₂）的异构化反应。本文研究首次提供了正十一烷/空气的激波管着火延迟时间。     

OTN在干线网中的规划思路及优势

OTN技术、产品和网络应用是近两年来国内通信业的一个热点.本文重点探讨OTN技术在干线传输网中的应用,包括网络容量和设备选用、波长分配调度和业务保护方式等内容.本文将主要从工程实用化角度进行讨论,不对OTN的技术实现细节进行探讨.     

水中上浮气泡动态特性研究

针对水中的上浮气泡,计入表面张力的作用,然后将气泡边界层内黏性效应分为法向和切向两部分,其中附加法向黏性应力通过Young-Laplace关系考虑;附加切向黏性力是基于黏性耗散能量等效原理,引入黏性修正压力代替.首先建立了轴对称和三维上浮气泡边界元模型,将数值结果与理论值和实验值进行对比分析,有良好的符合度,验证了数值模型的有效性;然后针对毫米量级上浮气泡的平衡速度与形态,讨论了气泡初始条件、表面张力和黏性对气泡上浮过程中动力学行为的影响;最后,提出了一种处理三维上浮气泡融合的数值方法,计算结果与实验现象符合良好,并且能够反映气泡融合后的复杂现象细节.     

利用π－/π+探测对称能的高密行为

利用同位旋和动量相关的IBUU相对论强子输运模型,以¹³²Sn+¹²⁴Sn碰撞在E/A=400MeV，b=1fm时为例,研究了在3种不同的对称能作用下发射粒子谱中π－/π＋的比率随时间和横动量的演化. 计算结果表明，π－/π＋的比率与核物质对称能的硬度有一个反向变化关系. 由于π介子主要来自于核反应形成的高密区,因此π－/π＋的比率可以作为精确研究核物质对称能高密行为的一个探针. 通过与实验数据的比较，就能够得出比以往更精确的关于对称能高密行为的重要信息.     

Numerical simulation of solid tumor angiogenesis with Endostatin treatment： a combined analysis of inhibiting effect of anti-angiogenic factor and micro mechanical environment of extracellular matrix

To investigate the influence of anti-angiogenesis drug Endostatin on solid tumor angiogenesis, a mathematical model of tumor angiogenesis was developed with combined influences of local extra-cellular matrix mechanical environment, and the inhibiting effects of Angiostatin and Endostatin. Simulation results show that Angiostatin and Endostatin can effectively inhibit the process of tumor angiogenesis, and decrease the number of blood vessels in the tumor. The present model could be used as a valid theoretical method in the investigation of anti-angiogenic therapy of tumors.     

Strain distributions and electronic structure of three-dimensional InAs/GaAs quantum rings

This paper presents a finite element calculation for the electronic structure and strain distribution of self-organized InAs/GaAs quantum rings. The strain distribution calculations are based on the continuum elastic theory. An ideal three-dimensional circular quantum ring model is adopted in this work. The electron and heavy-hole energy levels of the InAs/GaAs quantum rings are calculated by solving the three-dimensional effective mass Schr?dinger equation including the deformation potential and piezoelectric potential up to the second order induced by the strain. The calculated results show the importance of strain and piezoelectric effects, and these effects should be taken into consideration in analysis of the optoelectronic characteristics of strain quantum rings.     

索尼等离子旗舰MX42M1

继大屏幕CRT电视之后,在人们日益追求轻薄、时尚的今日,等离子(PDP)和液晶(LCD)电视逐渐走俏。相对于同一价位的两者产品,等离子电视的屏幕尺寸显然更大,而且它的亮度、颜色饱和度和纯度在屏幕上的每一角落表现比较均衡,反应速度也比液晶电视快出许多,观赏角度也更大。凭着这些