由复映射z←zα+c(α<0)所构造的广义M-集的研究

阐述了构造复映射z←z^α c(α<0)所构造的广义Mandelbrot集（简单称M－集或M－分形图）的逃逸时间算法。通过改变参数α,作出了一系列有趣的分形图,这些分形图为若干卫星群环绕中央恒星的星群结构,定量地研究了恒星和卫星群的几何结构,并对α取非整数时分形图的结构特点和卫星群胚胎出现的原因进行了分析,最后给出几点结论。     

备货型商品在三种销售价格下的利润函数（I）

本文考虑的是备货型商品的生产与优化管理。商品的生产过程是随机可控的。需求过程是一个根据销售价格高低来控制的随机过程。本文主要研究是这样一个系统的利润函数。     

Multi-scale Fractured Coal Gas–Solid Coupling Model and Its Applications in Engineering Projects

With coal mining entering the geological environment of “high stress, rich gas, strong adsorption and low permeability,” the difficulty of joint coal and gas extraction clearly augments, the risk of solid–gas coupling dynamic disasters greatly increases, and the underlying mechanisms become more complex. In this paper, based on the characteristics of coal’s multi-scale structure and spatiotemporal variation, the multi-scale fractured coal gas–solid coupling model (MSFM) was built. In this model, the interaction between coal matrix and its fractures and the mechanical characteristics of gas-bearing coal were considered, as well as their coupling relationship. By MATLAB software, the stress–damage–seepage numerical computation programs were developed, which were applied into Comsol Multiphysics to simulate gas flow caused by coal mining. The simulation results showed the spatial variability of coal elastic modulus and cross-flow behaviors of coal seam gas, which were superior to the results of traditional gas–solid coupling model. And the numerical results obtained from MSFM were closer to the measured results in field, while the computation results of traditional model were slightly higher than the measured results. Furthermore, the MSFM in a large scale was verified by field engineering project.     

Passive harmonic mode locked all-normal-dispersion Yb-doped fibre lasers

Passive harmonic mode-locking of dissipative solitons is demonstrated in all-normal dispersion Yb-doped fibre lasers.A difference equation model of the mode-locked fibre lasers is adopted to simulate the intra-cavity nonlinear dynamics.Hysteresis phenomena around the mode-locking threshold,and the effect of introducing linear phase bias are discussed.The passive harmonic mode-locking as one kind of multipulsing operations is revealed.Moreover,the simulation shows the bistability between multipulsing and single-pulse or period multiplication.     

颗粒堆的体积分数与制备流量关系的实验研究

通过实验研究发现,颗粒堆的体积分数随制备颗粒堆的颗粒流流量指数衰减,减小或增加流量到一定程度时,体积分数都达到饱和;出料口直径与颗粒粒径的比值小到一临界值时,随着流量的减小体积分数增加急剧变缓;颗粒粒径小到一临界值时,随着流量的增加,体积分数的减小急剧变缓.结合颗粒物质的强耗散性、空气作用、瓶颈效应和碰撞理论解释了实验现象,从连续性原理出发推出的颗粒堆体积分数随制备流量变化的函数与实验数据的拟合公式相同.     

光纤复合型油气井下压力温度测量系统

针对目前广泛使用的电子式油气井下压力温度测量系统可靠性低、高温环境漂移大的不足,设计了一种基于非本征型F-P干涉仪(EFPI)和光纤布喇格光栅(FBG)的复合型油气井下压力、温度测量系统,详细说明了其工作原理、传感器组成和信号解调方法,初步试验结果表明,该测量系统不仅克服了电子测量方式的不足,而且具有复用性好、测量精度高等优点.     

Concentric-ring structures in an atmospheric pressure helium dielectric barrier discharge

This paper performs a numerical simulation of concentric-ring discharge structures within the scope of a two-dimensional diffusion--drift model at atmospheric pressure between two parallel circular electrodes covered with thin dielectric layers. With a relative high frequency the discharge structures present different appearances of ring structures within different radii in time due to the evolvement of the filaments. The spontaneous electron density distributions help understanding the formation and development of self-organized discharge structures. During a cycle the electron avalanches are triggered by the electric field strengthened by the feeding voltage and the residual charged particles on the barrier surface deposited in the previous discharges. The accumulation of charges is shown to play a dominant role in the generation and annihilation of the discharge structures. Besides, the rings split and unify to bring and annihilate rings which form a new discharge structure.     

Dynamical measurements on viscoelastic behaviors of spiders in electro-dynamic loudspeakers

Spiders in electro-dynamic loudspeakers are most commonly concentrically corrugated fabric disks, and their viscoelastic behaviors affect the loudspeaker reproductions. A noncontact dynamic measuring technology is presented by a subwoofer closed box to excite the tested spiders pneumatically with a Laser Doppler Vibrometer (LDV) to measure the velocity of the moving spiders. Correlation techniques were employed to get an accurate and reliable acoustical transfer function between the measured velocity and sound pressure. The Young’s moduli of the tested spider composite materials were derived from the measured vibration modes. The creep effect and the level dependent behaviors of tested spiders were investigated. The results indicate that, the Young’s moduli of the tested spiders are frequency dependent. The mechanical stiffness increases with a small slope in low frequency range while a large slope in high frequency range. The loss factor exhibits the maximum around the resonance frequency, and after that it decreases with increasing frequency. The effective stiffness has a monotonic decrease with input voltage levels and the harder the spider, the less stiffness changes with input levels.     

一种新化合物K2Ti8O15纳米线

钛酸钾晶须通常是直径和长度在微米量级的无机晶须 ,可用Ｋ2 Ｏ·ｎＴｉＯ2 表示其组成 ,ｎ =1,2 ,4 ,6 ,8,[1] .六钛酸钾晶须具有耐高温、耐腐蚀、纤维拉伸强度高、导热系数小、红外反射率高 ,硬度低的特点 .在民用及工业方面有很多应用 .如催化剂载体、离子吸附交换材料、高温过滤器、绝热材料、耐摩擦材料等[2～ 5] .钛酸钾纳米线的合成尚未见报道 .我们在用电弧产生的Ｎ2 等离子体热解焦油时 ,生成了一种直径 9～ 2 0ｎｍ长约几百纳米线 .Ｘ射线能谱定量分析表明这种纳米线化学组成为Ｋ2 Ｔｉ8Ｏ15,是一种新的非化学计量化合物 .试验装…     

大面积染料敏化太阳电池的串联阻抗特性研究

在电子扩散微分方程的基础上,研究了染料敏化太阳电池光生电流和光生电压随光照强度不同的变化关系.提出敏化太阳电池串联阻抗功率损耗模型,理论模拟了大面积电池（有效面积>1 cm²）光电转换效率随多孔薄膜有效面积宽度变化的曲线、透明导电基底膜与银栅极的比接触电阻以及在不同入射光强下银栅极体电阻对大面积染料敏化太阳电池光伏性能的影响.结果表明透明导电基底膜的方块电阻和银栅极体电阻对大面积染料敏化太阳电池的性能有很大影响,而这种影响随光强的减弱逐渐减小. 关键词： 染料敏化 太阳电池 串联阻抗 光电转换效率