一种高速多通道光纤阵列光开关

为了对短时间大视场一维光强信息进行采集,采用编码转换技术和自聚焦透镜矩形阵列设计了光开关,用小口径电光晶体实现了大视场的测量.采用MOS管级联的高压同步电路,使得系统具有结构紧凑、性价比高、寿命长等优点.实验结果表明:开关选通时间100±5 ns,前后沿小于25 ns,消光比1 100∶1.     

有机垃圾厌氧发酵过程的生物反应热模型研究

为了考察有机厌氧发酵过程生物热对发酵系统温度的影响,利用微生物生长动力学模型方程式和各组分的物料衡算方程式,建立了有机垃圾厌氧发酵生物反应热的动力学模型,并通过遗传算法对模型部分参数进行了优化.计算结果与文献中的实验值最大相对误差小于2%,表明所建立的生物反应热模型基本可信.本文模型和计算结果可为有机垃圾厌氧发酵过程保温装置的优化设计提供参考依据.     

传质特性对光纤生物制氢反应器性能的影响

光生物制氢反应器的传质特性是影响反应器特性的重要因素.本文通过构造新型的光纤生物制氢反应器,采用生物膜法细胞固定化技术,考察在连续产氢条件下,进口底物浓度和流速对与反应器产氢相关特性的影响.结果表明:高浓度下出现的底物抑制现象是限制反应器性能的原因;流速改变的传质特性对反应器性能的影响,反映在驱动势和反应时间两个方面.     

叶片开缝的离心风机流场研究

本文提出在离心叶轮轮盖与叶片之间开缝,使得叶片压力面侧的高压气体射流到吸力面侧的低速尾迹区,从而直接给叶轮内的低速流体提供能量,减弱了叶轮内由于二次流所导致的射流-尾迹结构,并可用于消除或解决部分负荷时常发生的离心叶轮积灰问题.对某离心风机整机的数值模拟表明,在设计流量和小流量情况下,叶轮开缝后使叶片表面分离区域减小,整个流道速度分布更为均匀,改善了叶轮内部流场的流动状况,提高了离心叶轮性能和整机性能.研究表明,本方法对于提高离心式流体机械性能是有效的.     

不同燃烧当量比对二甲醚燃烧的影响研究

利用分子束质谱结合真空紫外同步辐射光电离技术研究了低压层流预混二甲醚/氧气/氩气火焰.通过测量火焰物种的离子信号强度随燃烧炉位置的关系曲线,计算了主要火焰物种的摩尔分数曲线.分析了燃料当量比(φ)为0.8,1.0和1.5时主要火焰物种的摩尔分数曲线,阐述了燃烧当量比对低压层流预混二甲醚/氧气/氩气火焰化学结构的影响.研究为进一步认识二甲醚燃烧提供了实验数据.     

Darboux Transformation and Soliton Solutions for Inhomogeneous Coupled Nonlinear Schrodinger Equations with Symbolic Computation

With the aid of computation, we consider the variable-coefficient coupled nonlinear Schrodinger equations with the effects of group-velocity dispersion, self-phase modulation and cross-phase modulation, which have potential applications in the long-distance communication of two-pulse propagation in inhomogeneous optical fibers. Based on the obtained nonisospectral linear eigenvalue problems （i.e. Lax pair）, we construct the Darboux transformation for such a model to derive the optical soliton solutions. In addition, through the one- and two-soliton-like solutions, we graphically discuss the features of picosecond solitons in inhomogeneous optical fibers.     

Improved nonlinear optimization in the storage ring of the modern synchrotron radiation light source

In the storage ring of the third generation light sources, nonlinear optimization is an indispensable course in order to obtain ample dynamic acceptances and to reach high injection efficiency and long beam lifetime, especially in a low emittance lattice. An improved optimization algorithm based on the single resonance approach, which takes relative weight and initial Harmonic Sextupole Integral Strength （HSIS） as search variables, is discussed in this paper. Applications of the improved method in several test lattices are presented. Detailed analysis of the storage ring of the Shanghai Synchrotron Radiation Facility （SSRF） is particularly emphasized. Furthermore, cancellation of the driving terms is investigated to reveal the physical mechanism of the harmonic sextupole compensation. Sensitivity to the weight and the initial HSIS as well as dependence of the optimum solution on the convergent factor is analyzed.     

Periodic, Quasiperiodic and Chaotic Discrete Breathers in a Parametrical Driven Two-Dimensional Discrete Klein-Gordon Lattice

We study a two-dimensional lattice of anharmonic oscillators with only quartic nearest-neighbor interactions, in which discrete breathers can be explicitly constructed by an exact separation of their time and space dependence. DBs can stably exist in the two-dimensional Klein-Gordon lattice with hard on-site potential. When a parametric driving term is introduced in the factor multiplying the harmonic part of the on-site potential of the system, we can obtain the stable quasiperiodic discrete breathers and chaotic discrete breathers by changing the amplitude of the driver.     

Anion Mass Spectrometry Study of Ion-Pair Photodissociation of CO2 in the XUV Energy 19.70-22.24eV

We demonstrate anion mass spectrometry using the Hefei synchrotron radiation source to investigate the ion-pair dissociation processes of molecules. The efficiency curve of the O^- anionic product via ion-pair dissociations of CO2 is recorded with tunable extreme vacuum ultraviolet photons （energy： 19.70-22.24 eV） and compared with the spectrum available in the literature. The possible dynamics of CO2 ＋ hv → CO^＋＋ O^- in this energy range is discussed.