Chalcogenide Fibers: An Overview of Selected Applications

Chalcogenide glass fibers have many unique properties that make them attractive for applications that are not possible with silica fibers. Selected applications of chalcogenide fibers in research, commerce, and the military are reviewed.     

Some mathematical aspects of Anderson localization: boundary effect,multimodality, and bifurcation

Anderson localization is a famous wave phenomenon that describes the absence of diffusion of waves in a disordered medium. Here we generalize the landscape theory of Anderson localization to general elliptic operators and complex boundary conditions using a probabilistic approach, and further investigate some mathematical aspects of Anderson localization that are rarely discussed before. First, we observe that under the Neumann boundary condition, the low energy quantum states are localized on the boundary of the domain with high probability. We provide a detailed explanation of this phenomenon using the concept of extended subregions and obtain an analytical expression of this probability in the one-dimensional case. Second, we find that the quantum states may be localized in multiple different subregions with high probability in the one-dimensional case and we derive an explicit expression of this probability for various boundary conditions. Finally, we examine a bifurcation phenomenon of the localization subregion as the strength of disorder varies. The critical threshold of bifurcation is analytically computed based on a toy model and the dependence of the critical threshold on model parameters is analyzed.     

辣椒碱与β-环糊精包合物的核磁共振研究

利用核磁共振方法研究了辣椒碱β-环糊精包合物的化学计量比、空间结构信息及其在水溶液中的自扩散系数. 通过测定不同浓度比的辣椒碱和β-环糊精混合溶液的 ¹H NMR数据,绘制Job's曲线,辣椒碱和β-环糊精的Job's曲线均在r=0.5处出现拐点. 同时测定了该包合物的2D ROESY和DOSY谱图,ROESY谱图中NOE交叉信号出现在辣椒碱的H-1~H-8和β-环糊精的H-3′、H-5′、H-6′之间,DOSY测得β-环糊精和辣椒碱形成包合物前后的表观自扩散系数. 结果表明,辣椒碱β-环糊精包合物的主客体分子的化学计量比为1∶1,辣椒碱分子的异丙基端从β-环糊精的宽口端进入疏水腔,其中H-1~H-8部分在空腔内部,包合物的自扩散系数为2.95×10^-10m²/s.     

The ρ-π Puzzle of J/φ and φ′ Decays

The recent BES Collaboration data on φ →PV, particularly the isospin violating mode φ′ → π^oω^o and finding of a finite number for B(φ′ → K^*OK^O), enable us now to deal more precisely about the challenges to theory concerning this extraordinary and remarkableso-called ρ-π puzzle of J/φ and φ′ decays. In terms of the existing data and deploying the simplest phenomenology, measurement of φ′ → π⁺π^- and whether a finite number for the K^*+K^- mode might require a significantly large accumulation of data remain interesting questions.     

HL-2M 装置时序控制与数据采集系统设计

基于 FPGA 和 IEEE1588PTPv2 协议设计了 HL-2M 装置时序控制系统,用于在精准时刻为测控系统 提供触发。数据采集系统采用客户端/服务端双模式管理。在 HL-2M 装置初始等离子体放电实验中测试结果表明, 时序控制和采集系统具有纳秒级精度触发,实时性强,数据传输速度快,稳定可靠,方便部署和管理的特点,满 足 HL-2M 等离子体放电实验的应用需求。     

Interaction of Wave Trains with Defects

The evolution and transition of planar wave trains propagating through defects(obstacles) in an excitable medium are studied. When the frequency of the planar wave trains is increased, three different dynamical regimes,namely fusion, "V" waves, and spiral waves, are observed in turn and the underlying mechanism is discussed. The dynamics is concerned with the shapes of the defects. Circle, triangle, and rectangle defects with different sizes are considered. The increase of pacing frequency broadens the fan-shaped broken region in the behind of a rectangle defect.The increase of width of a triangle defect leads to breakup of wave trains easier while the change of height shows opposite effect, which is presented in a phase diagram. Dynamical comparison on defects with different shapes indicates that the decrease of the defect width along the propagation of wave trains makes the fan-shaped region and the minimal frequency for breakup of spiral both increased.     

面向集成模拟平台的远程协作系统

基于 Web 技术,采用三层模型的系统架构,分别使用 AJAX、SQLite、Openlava 和 Python 解决了 数据异步传输、作业结果重用、多用户作业管理和可视化显示等关键技术,成功开发出面向集成模拟平台的远程 协作系统——SICOS。通过 Web 浏览器即可多人同时运行高性能计算集群上 IMAS 框架下的等离子体程序,实 现了程序的集成运行及运行结果的远程分析、数据共享和可视化显示等功能。通过率先集成 EFIT 可以获得 HL-2A 装置实验的平衡位形重建结果和 HL-2M 装置期望的平衡位形结果,为后续其它程序的集成奠定了技术基础。     

环位形下鱼骨模驱动快离子输运的数值模拟研究

考虑包含动理学效应的鱼骨模结构,使用导心轨道程序 ORBIT,在磁面坐标下研究了不同的扰动模 幅度、频率对快离子再分布的影响,并分析了粒子与扰动发生共振的条件。模拟得出,鱼骨模扰动会使快离子在 实空间、相空间中发生再分布,芯部( ψ_p/ψ _w≤0.2 ,ψ_p 为极向磁通,ψ_w 为最后一个闭合磁面的磁通)快离子密 度下降约 20%,中间磁面位置上( ψ_p/ψ _w≥0.2,ψ_p/ψ _w≤ 0.6)的快离子密度增加约 7%;通过扫描频率发现,相空间中快 离子的再分布对模式频率敏感,并分析了快离子与鱼骨模扰动共振的条件。     

CFETR N-NBI验证样机恒温供水系统的设计

通过分析中国聚变工程实验堆(CFETR)的基于负离子源的中性束注入系统(N-NBI)验证样机中等离子体电极的工况,确定了其恒温供水的技术参数,设计出了CFETR N-NBI验证样机恒温供水系统。     

Thermodynamics of 4D dS/AdS Gauss–Bonnet black holes according to consistent gravity theory in the presence of a cloud of strings

By looking at the Lovelock theorem one can infer that the gravity model given by [1] cannot be applicable for all types of 4D Einstein–Gauss–Bonnet (EGB) curved space-time. The reason for this is that in 4D space-time, the Gauss–Bonnet invariant is a total derivative and hence it does not contribute to gravitational dynamics. Hence, the authors of [2] presented an alternative consistent EGB gravity model instead of [1] by applying a break-of-diffeomorphism property. In this work, we use the alternative model to produce a de Sitter (dS)/Anti-de Sitter (AdS) black hole metric and then investigate its thermodynamic behavior in the presence of a cloud of Nambu–Goto strings. Mathematical derivations show that the resulting diagrams of pressure vs specific volume at a constant temperature are similar to that for a van der Waals gas/fluid in an ordinary thermodynamic system in the dS sector but not in the AdS background. From this, we infer that the black hole participates in the small-to-large black hole phase transition in the dS background, while it exhibits a Hawking–Page phase transition in the AdS background. In the latter case, an evaporating black hole eventually reaches an AdS vacuum space because of its instability.     

Solutions of the SchrödingerEquation forPT-Symmetric Coupled Quintic Potentialsin Two Dimensions

This paper deals with the solutions of time independent Schrödinger wave equation for a two-dimensional PT-symmetric coupled quintic potential in its most general form. Employing wavefunction ansatz method, general analytic expressions for eigenvalues and eigenfunctions for first four states are obtained. Solutions of a particular case are also presented.     

Darboux Transformation and N-soliton Solution for Extended Form of Modified Kadomtsev-Petviashvili Equation with Variable-Coefficient

The extended form of modified Kadomtsev-Petviashvili equation with variable-coefficient is investigated in the framework of Painlevé analysis. The Lax pairs are obtained by analysing two Painlevé branches of this equation. Starting with the Lax pair, the N-times Darboux transformation is constructed and the N-soliton solution formula is given, which contains 2n free parameters and two arbitrary functions. Furthermore, with different combinations of the parameters, several types of soliton solutions are calculated from the first order to the third order. The regularity conditions are discussed in order to avoid the singularity of the solutions. Moreover, we construct the generalized Darboux transformation matrix by considering a special limiting process and find a rational-type solution for this equation.     

Bidirectional Quantum Secure Direct Communication Network Protocol with Hyperentanglement

We propose a bidirectional quantum secure direct communication (QSDC) network protocol with the hyperentanglment in both the spatial-mode ad the polarization degrees of freedom of photon pairs which can in principle be produced with a beta barium borate crystal. The secret message can be encoded on the photon pairs with unitary operations in these two degrees of freedom independently. Compared with other QSDC network protocols, our QSDC network protocol has a higher capacity as each photon pair can carry 4 bits of information. Also, we discuss the security of our QSDC network protocol and its feasibility with current techniques.     

卷丹皂苷A和甾体皂苷的NMR特征

应用2D NMR技术：¹H-¹H COSY、HMQC、HMBC全归属新化合物卷丹皂苷A和已知化合物麦冬皂苷D′ 的碳和氢质子信号，总结薯蓣皂苷元类型甾体皂苷的NMR特征，为该类型化合物的结构鉴定提供光谱学依据.     

On Improving Accuracy of Finite-Element Solutions of the Effective-Mass Schrödinger Equation for Interdiffused Quantum Wells and Quantum Wires

We use the Galerkin approach and the finite-element method to numerically solve the effective-mass Schrödinger equation.The accuracy of the solution is explored as it varies with the range of the numerical domain.The model potentials are those of interdiffused semiconductor quantum wells and axially symmetric quantum wires.Also,the model of a linear harmonic oscillator is considered for comparison reasons.It is demonstrated that the absolute error of the electron ground state energy level exhibits a minimum at a certain domain range,which is thus considered to be optimal.This range is found to depend on the number of mesh nodes N approximately as α₀ log_e^α₁(α₂ N),where the values of the constants α₀,α₁,and α₂ are determined by fitting the numerical data.And the optimal range is found to be a weak function of the diffusion length.Moreover,it was demonstrated that a domain range adaptation to the optimal value leads to substantial improvement of accuracy of the solution of the Schrödinger equation.     

Double Diffractive Dissociation Process p + p(p) → Xp + Xp(p) + Π+ + Π- at High Energy and the Pomeron Model of Donnachie-Landshoff

Large p_γ charged pion pair produced in Double Diffractive Dissocjation (DDD) process at high energy is studied with double pomeron (IP) exchange mechanism. Using DonnachieLandshoff pomeron model we have calculated the cross-section of the process at the energy interval from ISR to LHC when the rapidity of the charged pions is approximately equal to zero. It is shown that this process is the favorite in experiments which could effectively be used to examine Donnachie-Landshoff pomeron model and provide a possibility to check the value of the suppression coefficient N².     

基于荧光光谱法与深度信念网络的稻种发芽率检测方法研究

针对传统稻种发芽率检测效率低、精度差、专业化要求高等问题,通过荧光光谱法结合深度信念网络(DBN)建立稻种发芽率预测模型。首先,将连粳7号和武运粳均分别老化0~7 d后,以5 min为间隔在纯净水中分别浸泡5~30 min。然后用荧光光谱仪检测浸泡液的荧光光谱,光谱数据经中心化后用集合经验模态分解(EEMD)去噪,并通过主成分分析法提取441.5 nm的特征荧光波长。最后,利用偏最小二乘回归(PLSR),反向传播神经网络(BPNN),径向基函数神经网络(RBFNN)和深度信念网络(DBN)建立水稻种子发芽预测模型。比较后得出,DBN模型在少数据、弱信号情况下的预测精度最高,预测集相关系数Rp和均方根误差RMSEP最大可达0.979 2和0.101。同时,通过分析混合稻种荧光数据R_p的变化趋势,得到最佳浸泡时间为22.1 min,实际上,精确度超过0.95(R_p)需要5 min左右。研究结果表明,结合荧光光谱法和EEMD-DBN模型,非破坏性地预测水稻种子发芽率具有可行性和高准确性,并且适用于不同颜色和污染水平的水稻种子的检测。     

“爱迪生”珍珠及染色处理有核珍珠的谱学特征

颗粒大、圆度高并具有浓郁颜色的淡水有核养殖珍珠（商贸名称为“爱迪生”珍珠）为珍珠市场提供了更高的品质与价值,然而受利益的驱使,染色的有核养殖珍珠也逐渐流入市场,扰乱了消费者的健康消费,在一定程度上阻碍了“爱迪生”珍珠产业的良性发展。本文利用红外光谱仪、紫外-可见分光光度计和光致发光光谱仪对养殖和染色“爱迪生”珍珠进行了系统的谱学研究,并将其与海水珍珠、染色海水珍珠进行了比较。结果表明：（1）染色与养殖“爱迪生”珍珠在红外光谱上均显示1 445,882和725 cm-1处的文石振动峰,其中染色“爱迪生”珍珠在3 800 cm-1处均出现宽缓的弱吸收峰;（2）染色“爱迪生”珍珠的紫外可见光光谱中280 nm处的吸收峰明显弱于养殖“爱迪生”珍珠,染色后的“爱迪生”珍珠整体反射率降低,可能与染剂使珍珠中的蛋白质分子受损有关。染黄色“爱迪生”珍珠缺失养殖橙黄色“爱迪生”珍珠在360～380 nm处的吸收峰,而与染色海水金珠430 nm处的强吸收峰相似。染黑色“爱迪生”珍珠在425 nm处有吸收峰,染色海水黑珍珠在480和645 nm处有吸收峰,养殖海水黑珍珠在702 nm处有吸收峰,三者图谱的差异可能为各自的染料不同所致;（3）养殖“爱迪生”珍珠在光致发光光谱中450～550 nm范围内可见一组吸收峰,染色“爱迪生”珍珠的发光中心向红区偏移且在650 nm附近出现强度不等的与染色剂相关的吸收峰,染色海水金珠也在600 nm处有和染色剂有关的吸收峰。     

Exact Solitary Wave Solutions of Surface Waves in a Convecting Fluids

In the standard Painlevé analysis, the singular manifold can be extended to many different forms because of its arbitrariness. Using some kinds of standard and nonstandard truncation approaches for the extended singular manifolds to a convecting fluid, we can obtain abundant solitary wave structures.