以太无源光网络中面向多播业务的节能算法(英文)

在面向多播业务的以太无源光网络中引入光网络单元混合休眠模式,提出面向多播业务的节能算法和改进的面向多播业务的节能算法,使光网络单元空闲组件能够得到充分休眠,并通过约束条件降低光网络单元的唤醒次数,从而降低光网络单元能耗.改进的面向多播业务的算法与面向多播业务的算法相比,增加了光网络单元唤醒的约束条件,进一步降低了光网络单元的唤醒次数.仿真结果表明,与现有算法相比,所提算法在保证数据包时延的前提下更加节能.改进的面向多播业务的算法节能效果优于面向多播业务的算法,表明增加的约束条件有助于降低光网络单元的唤醒次数和能耗.     

Diffusion of14C in dense saturated bentonite under steady-state conditions

Diffusion coefficients are critical parameters for predicting migration rates and fluxes of contaminants through clay-based barrier materials used in many waste containment strategies. Cabon-14 is present in high-level nuclear fuel waste and also in many low-level wastes such as those generated from some medical research activities. Diffusion coefficients were measured for¹⁴C (in the form of carbonate) in bentonite compacted to a series of dry bulk densities, _b, ranging from about 0.9 to 1.6 Mg/m³. The clay was saturated with a Na-Ca-Cl-dominated groundwater solution typical of those found deep in plutonic rock on the Canadian Shield. Both effective,D _e, and apparent,D _a, diffusion coefficients were determined.D _e is defined asD _{0 a} n _e, where D₀ is the diffusion coefficient in pure bulk water, _a the apparent tortuosity factor, andn _e the effective porosity available for diffusion; andD _a is defined asD _{0 a} n _e/(n _e + _b K _d ), where K_d is the solid/liquid distribution coefficient. BothD _e andD _a decrease with increasing _b:D _e values range from about 10×10^–12 m²/s at _b0.9 Mg/m³ to 0.6×10^–12 m²/s at 1.6 Mg/m³, andD _a values vary from approximately 40×10^–12 to 4×10^–12 m²/s over the same density range. The decrease inD _e andD _a is attributed to a decrease in both _a andn _e as _b increases. The data indicate thatn _e is <10% of the total solution-filled porosity of the clay at all densities.K _d values for¹⁴C with the clay range from about 0.3 to <0.1 m³/Mg; this indicates there is a small amount of¹⁴C sorbed on the clay and/or some¹⁴C is isotopically exchanged with¹²C in carbonate phases present in the clay. Finally, theD _e values for¹⁴C are lower than those of other diffusants — I^–, Cl^–, TcO₄ ^–, and Cs⁺ — that have been measured in this clay and pore-water solution. This is attributed to lower values for bothn _e andD ₀ for¹⁴C species relative to those of the other diffusants.     

基于可控式被动阻尼的静电陀螺仪启动控制系统

静电陀螺仪(ESG)的启动阻尼是一个转子最大惯性主轴与转轴对准的过程。采用直流磁场的可控式被动阻尼方法有效地解决了转子极性倒置问题。中介绍了基于可控式被动阻尼ESG启动控制系统的设计和研制，该系统以浮点DSP芯片TMS320C32为核心电路，具有转子阻尼、极性识别与控制、故障检测、转速测定、恒速控制和RS232通讯等功能。在气浮装置上证实了所研制的系统能有效实现上述功能。     

THE CAUCHY INTEGRAL OF MANY COMPLEX VARIABLES PASSIVE OPERATORS AND MULTIDIMENSIONAL DISPERSION RELATIONS

This note illustrates the multidimensional dispersion relations that connect the realand imaginary parts of the matrix z(p):where(?)(p)is the boundary value of the impedance(?)(ζ).     

斜拉索振动控制中MR阻尼器选型的研究

以全索全时段振动响应的均方根(RMS)评价MR阻尼器对斜拉索的减振效果。计算结果表明MR阻尼器型号是影响斜拉索减振效果的最主要因素。斜拉索的减振效果在选用合适的MR阻尼器时达到最佳。进而研究了MR阻尼器型号与阻尼器安装位置、施加的电压、斜拉索基频(张力、索长、质量)、激励荷载(类型、频率、幅值)等各种因素的关系,为MR阻尼器合理选型提供了优化设计的方法。型号选用主要是与斜拉索基频和MR阻尼器安装位置有关。在引起索基频变化的因素中,索质量对型号的选取影响最大;而索长对型号影响不大。对于索质量较大、张力较大、MR阻尼器安装位置较低、外界激励较大、频谱特征多变、低频为主时需要较强的MR阻尼器。进一步研究表明,半主动控制与开环控制的最优MR阻尼器型号有较好的一致性,因此半主动控制所选用的MR阻尼器型号可参照被动控制时最优MR阻尼器型号。     

Experimental investigation of steel spheres as a passive enhancement technique for flash boiling of HCFC-22

An experimental investigation was conducted to study the influence of a layer of 3.6-mm-diameter steel spheres on the mass flow during flash boiling in a glass pressure vessel. It was observed that the steel spheres added numerous heterogeneous nucleation sites within the liquid and promoted abundant vapor bubble growth during depressurization. The steel spheres were in contact with each other and with the interior of the glass vessel. The data from these experiments were compared with baseline experimental results primarily with regard to the mass flow. Each test was run for 60 s, using controlled variables of orifice diameters (1.59 and 5.56 mm), initial refrigerant amounts (0.23, 0.45, and 0.68 kg), initial pressures (575 and 840 kPa), and vessel geometries (665 and 1110 ml). Pressures, temperatures, and mass flow rates, along with calculated saturation temperatures, amount of superheat, mass flux, and total mass flashed, were used to compare the baseline experiments with the enhanced boiling method. Results showed an increase in the total mass flashed at each test condition, ranging from an average of 22% to 81% with respect to baseline experiments.     

Multi-soliton management by the integrable nonautonomous nonlinear integro-differential Schrödinger equation

We consider a wide class of integrable nonautonomous nonlinear integro-differential Schrödinger equation which contains the models for the soliton management in Bose–Einstein condensates, nonlinear optics, and inhomogeneous Heisenberg spin chain. With the help of the nonisospectral AKNS hierarchy, we obtain the N-fold Darboux transformation and the N-fold soliton-like solutions for the equation. The soliton management, especially the synchronized dispersive and nonlinear management in optical fibers is discussed. It is found that in the situation without external potential, the synchronized dispersive and nonlinear management can keep the integrability of the nonlinear Schrödinger equation; this suggests that in optical fibers, the synchronized dispersive and nonlinear management can control and maintain the propagation of a multi-soliton.     

Full-Duplex Link Providing Alternative Wired and Wireless Broadband Access for the Wavelength-Division Multiplexing Passive Optical Network with a Uniform Converged Signal Format

Abstract

A full-duplex link implementing alternative wired and wireless access for wavelength-division multiplexing passive optical network is proposed with the uniformed three-tone converged optical signal, which provides a wired or wireless downlink access signal alternatively and an uplink optical carrier. The uplink optical carrier reversed by the converged optical signal makes the hybrid optical node unit free from the optical source. The simulation results show that the full-duplex link with a 10-Gb/s 16-quadrature amplitude modulation (16-QAM) downstream and 5 Gb/s binary upstream can provide both wired access with a bit-error rate below 10^?9 and radio-over-fiber-based wireless access with a bit-error rate below 10^?7 over 40 km of fiber without an optical source and optical amplifier in the hybrid optical node unit.     

全光纤光反馈环形腔结构多路激光被动相干合成

提出了基于全光纤光反馈环形腔结构的多路光纤激光相干合成方案,实现了多路激光的被动相干合成。全光纤结构避免了传统孔径拼接输出结构的旁斑能量耗散问题,保证了合成光束的光束质量。开展了实验研究,实现了4路光纤激光的相干锁相输出,获得时域、空域特性均十分稳定的合成光束,合成效率为96.1%,取得较好的合成效果。