零排放燃气轮机的空气动力学特性

本文对采用二氧化碳作为基本工作流体的半闭环燃气轮机循环的空气动力学特性进行了详尽的分析.结果表明,不同工作流体的比热比值对压气机的压比、等熵效率及临界堵塞质量流量影响很大,并详细阐述了一种比热比对透平机械性能影响的修正方法,进而提出了一种零排放发动机的设计新思路,揭示了最初为空气工质而设计的压气机可以直接用于CO2零排放发动机中.     

Entanglement in One-Dimensional Random XY Spin Chain with Dzyaloshinskii--Moriya Interaction

The impurities of exchange couplings, external magnetic fields and Dzyaloshinskii-Moriya （DM） interaction considered as Gaussian distribution, and the entanglement in one-dimensional random XY spin systems is investigated by the method of solving the different spin-spin correlation functions and the average magnetization per spin. The entanglement dynamics at central locations of ferromagnetic and antiferromagnetic chains have been studied by varying the three impurities and the strength of DM interaction. （i） For the ferromagnetic spin chain, the weak DM interaction can improve the amount of entanglement to a large value, and the impurities have the opposite effect on the entanglement below and above critical DM interaction. （ii） For the antiferromagnetic spin chain, DM interaction can enhance the entanglement to a steady value. Our results imply that DM interaction strength, the impurity and exchange couplings （or magnetic field） play competing roles in enhancing quantum entanglement.     

Entanglement reciprocation between two charge qubits and two-cavity field

We propose a simple scheme to generate two-mode entangled coherent state in two separated cavities and realize the entanglement reciprocation between the superconducting charge qubits and continuous-variable system. By measuring the state of charge qubits, we find that the entanglement of two charge qubits, which are initially prepared in the maximally entangled state, can be transferred to the two-cavity field, and at this time the two-cavity field is in the entangled coherent state. We also find that the entanglement can be retrieved back to the two charge qubits after measuring the state of the two-cavity field.      

多帧融合处理技术在运动模糊图像复原中的应用

运动模糊图像是电视监控中常见的退化图像 ,也是图像处理和检验工作中的难题。针对电视摄像的特点 ,多帧融合处理技术从图像时间序列中提取景物的运动信息 ,构造复原滤波器 ,通过频率域反转滤波方式复原模糊图像。这项技术能够有效地增强电视监控中存在的运动模糊图像 ,并且适用于数字视频图像处理     

Wronskian and Grammian Determinant Solutions for a Variable-Coefficient Kadomtsev-Petviashvili Equation

In this paper, we derive the bilinear form for a variable-coefficient Kadomtsev Petviashvili-typed equation. Based on the bilinear form, we obtain the Wronskian determinant solution, which is proved to be indeed an exact solution of this equation through the Wronskian technique. In addition, we testify that this equation can be reduced to a Jacobi identity by considering its solution as a Grammian determinant by means of Pfaffian derivative formulae.     

Azimuthal correlations between directed and elliptic flow in heavy ion collisions

A method for investigating the azimuthal correlations between directed and elliptic flow in heavy ion collisions is described.The transverse anisotropy of particle emission at AGS energies is investigated within the RQMD model.It is found that the azimuthal correlations between directed and elliptic flow are sensitive to the incident energy and impact parameter.The fluctuations in the initial stage and dynamical evolution of heavy ion collisions are not negligible.     

Entanglement for Two-Qubit Extended Werner-Like States： Effect of Non-Markovian Environments

We investigate the sudden birth and sudden death of entanglement of two qubits interacting with uncorrelated structured reservoirs. The system is initially prepared in two-qubit extended Werner-like state. We work out the dependence of the entanglement dynamics on both non-Markovian environments and the purity of initial state, and show that non-Markovian environments and the purity can control the time of the two-qubit entanglement sudden death and the reservoirs＇ entanglement sudden birth. Furthermore, under the conditions of different purity and initial entangIement, the revival of qubits＇ entanglement can manifest before, simultaneously or even after the disentanglement of their corresponding reservoirs.     

聚谷氨酸发酵过程中ATR-FTIR光谱信号的分数阶基线校正

采用衰减全反射傅里叶变换红外光谱法（ATR-FTIR）,结合多元校正模型对γ-聚谷氨酸（γ-PGA）发酵过程中两种主要底物葡萄糖和谷氨酸钠的浓度进行间接测量,为优化发酵系统控制提供重要的反馈信息。光谱测量中经常出现的基线漂移会严重影响后续多元校正模型的性能,需要采用基线校正算法对光谱进行预处理。现有流行的基线校正算法多数是基于Whittaker Smoother（WS）平滑算法,这些算法均采用整数阶微分对拟合基线进行约束,表达能力有限。针对现有基线校正算法中的整数阶微分自适应性差的问题,利用更加灵活的分数阶微分对基线进行约束,提出了一种基于分数阶的基线校正算法,实现对整数阶基线校正的扩展。总共进行了5个批次的γ-PGA发酵实验,并对不同批次和全部批次的ATR-FTIR光谱数据分别进行了分数阶基线校正,模型的预测精度均得到不同程度的提升。实验结果表明,只有在批次2时,基于整数阶的基线校正效果最好;其他批次的基线校正效果最好时的阶次均为分数阶。这也表明了分数阶微分（包含整数阶微分）对基线的约束更加合理。同时发现全部批次的整体基线校正效果远远差于单一批次的效果,原因可能是各批次发酵光谱的基线是不同的,对不同的批次需要选用不同的阶次以获得最佳的基线校正。此外,γ-PGA发酵样品的ATR-FTIR光谱测量是以蒸馏水为背景,会在3 100~3 600 cm-1波数范围内出现负水峰,形成有害的干扰信号;分数阶基线校正后的光谱表明,分数阶基线校正算法将负的水峰当作基线,在一定程度上进行了消除。综上分析,分数阶基线校正算法不仅扩展了传统整数阶基线校正算法的应用范围,也为消除ATR光谱中负的水峰提供了新的解决思路。     

基于SVM集成学习的网络故障诊断方法

针对现有SVM多分类方法在网络故障诊断中识别精度较低的问题,本文提出一种基于二叉树结构和模型二重扰动的SVM集成学习算法。通过集成学习思想提高网络故障诊断的精度。在集成过程中对二叉树结构和核参数进行扰动,加大个体分类器的差异度,提升了诊断模型的泛化性。在实际网络中的诊断实验表明所提的方法较二叉树等其它SVM多分类方法具有更高的诊断精度。     

自耦合射流强化掺混的数值研究

针对同向两股气流掺混的某一特定物理模型,对自耦合射流作用下的气流掺混过程进行了数值模拟研究.与未施加自耦合射流激励的掺混过程相比,自耦合射流周期性的吹/吸诱导流场内产生复杂的大尺度涡系结构,使得同向两股气流形成对流型混合,有效缩减了主流核心区长度;相对于在燃烧室单侧放置激励器的方式,双侧自耦合射流激励时温度均匀分布线较...