54 resultados para Moibanus, Ambrosius, 1494-1554.
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
叙述了高速可压缩边界层流动稳定性转捩点预报的数值计算法。特别是Rayleigh反迭代法与边界层渐近匹配方法的配合,有效地提高了计算精度,节省了存储和计算时间。该文的研究结果与已有的实验结果一致。
Resumo:
本文基于分层边坡在水位涨落时发生滑坡的模拟实验,简要描述了实验中的主要现象,计算了实验模拟的分层坡体内与水位变化直接相关的动态渗流场、孔隙水压力场与渗透速度场分布.根据计算结果,对水位变化导致坡体变形失稳的机理进行了分析,为这类分层边坡滑坡的治理提供了依据.
Resumo:
Cylindrical cellular detonation is numerically investigated by solving two-dimensional reactive Euler equations with a finite volume method on a two-dimensional self-adaptive unstructured mesh. The one-step reversible chemical reaction model is applied to simplify the control parameters of chemical reaction. Numerical results demonstrate the evolution of cellular cell splitting of cylindrical cellular detonation explored in experimentas. Split of cellular structures shows different features in the near-field and far-field from the initiation zone. Variation of the local curvature is a key factor in the behavior of cell split of cylindrical cellular detonation in propagation. Numerical results show that split of cellular structures comes from the self-organization of transverse waves corresponding to the development of small disturbances along the detonation front related to detonation instability.
Resumo:
本文利用基于非正交网格的二阶精度有限体积法,对氨热法生长过程中温度场和流场进行了模拟,其中隔板开孔率分别为10%(中心开孔5%,侧壁与隔板边缘开孔5%)和20%(中心开孔10%,侧壁与隔板边缘开孔10%).通过对流场和温度场的分析,了解了高压釜内部营养素的输运及溶液结晶的本质.结果显示在釜底的多孔介质层流动较弱,在流体层流动较强.在多孔介质层热量的输运主要通过热传导;在流体层中,流体与原料的分界处以及流体和高压釜的侧壁出现了大的温度梯度.
Resumo:
对串联的长周期光纤光栅(CLPFG)的透射谱特性进行了理论分析和实验研究。分析表明,长周期光纤光栅中纤芯模和包层模之间的马赫-曾德尔干涉效应导致在长周期光纤光栅谐振峰内的梳状滤波结构特性;其峰值位置和峰间距同串联区光纤的长度以及光纤的波导色散因子有关。测量了长周期光纤光栅的透射谱,并研究了其温度特性。根据测量数据,得到对应于1554nm波长处,所用单模光纤HE14模的波导色散因子γ为0.874;纤芯/包层有效折射率差的热光系数为4.8×10^-5℃^-1。并对这一测试方法和结果,以及长周期光纤光栅的应用进
Resumo:
星间激光通讯中,精跟踪起着十分重要的作用,而精密偏转镜(FSM)是精跟踪系统中最为关键的部件.基于光学矢量反射定律,推导得到了FSM的精确光学特性,这一特性为精跟踪控制系统提供了精确的理论依据.设计了基于FSM精确光学特性的精跟踪控制系统,对系统整定所用的单纯形法进行了两点重要改进,并对所设计的精跟踪系统进行了数字模拟,由此实现了对FSM的精确控制,提高了精跟踪系统的精确性;将光学衍射超分辨原理应用到星间激光通讯中.利用三区位相光瞳滤波器的超分辨性能,改变光学系统的点扩散函数,从而改变接收端焦平面上的光强
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A visual pattern recognition network and its training algorithm are proposed. The network constructed of a one-layer morphology network and a two-layer modified Hamming net. This visual network can implement invariant pattern recognition with respect to image translation and size projection. After supervised learning takes place, the visual network extracts image features and classifies patterns much the same as living beings do. Moreover we set up its optoelectronic architecture for real-time pattern recognition. (C) 1996 Optical Society of America
Resumo:
Based on the Mach-Zehnder effect between the core mode and the cladding modes, the interference fringes are formed by a pair of cascaded long-period fiber gratings (CLPFGs). Theoretical analyses show that the spectral spacing and the wavelength of these fringes are functions of the waveguide dispersion factor gamma, which is a characterizing parameter to LPFG and with theoretical and applicational significance. By measuring the characteristics of the transmission spectra of CLPFGs, the absolute value of gamma can be obtained. At the same time, the thermo-optic coefficient of effective refractive index difference between core and cladding modes, p, can also be obtained by measured the temperature sensitivity of these fringes. In the experiments, \gamma\ and mu were measured by this method to be 0.874 and 4.08 x 10(-5) degreesC(-1), respectively, for LPFGs with period of 450 mum and with a HE14 resonant peak at 1554 nm. (C) 2004 Elsevier B.V. All rights reserved.
Resumo:
We investigated the use of a deep-etched fused-silica grating with triangular-shaped grooves as a highly efficient polarizing beam splitter (PBS). A triangular-groove PBS grating is designed at a wavelength of 1550 nm to be used in optical communication. When it is illuminated in Littrow mounting, the transmitted TE- and TM-polarized waves are mainly diffracted in the minus-first and zeroth orders, respectively. The design condition is based on the average differences of the grating mode indices, which is verified by using rigorous coupled-wave analysis. The designed PBS grating is highly efficient over the C+L band range for both TE and TM polarizations (> 97.68 %). It is shown that such a triangular-groove PBS grating can exhibit a higher diffraction efficiency, a larger extinction ratio, and less reflection loss than the binary-phase fused-silica PBS grating. (C) 2008 Optical Society of America.
Resumo:
给出描述光波通过傍轴光学系统衍射的柯林斯公式及其逆运算表达式,然后将数字全息检测研究中的物平面及CCD探测平面视为ABCD系统的输入平面及输出平面,提出通过柯林斯公式的逆运算进行波面重构的一种计算方法。为便于该方法的实际应用,研究了参考光是球面波时全息图的频谱结构,并从理论上证明,全息图的频率空问中存在可以通过滤波器分离的物光及共轭物光的频谱。最后.通过理论模拟及实验研究证明了使用柯林斯公式的逆运算重构波面的可能性。
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制备了不同氟化物含量的(1-x)TeO2-AlF3(x=10%,20%,30%,按摩尔计)透明氟碲酸盐玻璃。利用差热分析和Raman光谱对玻璃的性质和结构进行研究。结果显示:当x达到30%时,氟化铝以Al-F多面体的形式进入玻璃网络结构。随着氟化物含量增加,玻璃在中红外区的透过率提高,玻璃结构单元从[Te(O,F)4]三方双锥向[Te(O,F)3]三方锥转变。Raman光谱显示:1个宽的强峰出现在750~840cm^-1,表明玻璃中Te-O键长介于0.185-0.196nm之间。
Resumo:
本研究运用JKLMNOP逆行追踪结合胆碱乙酰化酶免疫组织化学法研究了树鼠句内侧隔核M斜角带复合体向腹侧海马 的投射Q结果表明B)R+树鼠句腹侧海马接受内侧隔核M斜角带复合体的投射有三种形式B即来自内侧隔核B内侧隔核M斜角带垂直部 的外侧部和内侧隔核M斜角带垂直部的后部Q)G+腹侧海马来自内侧隔核和斜角带垂直部的投射主要是非胆碱能的B其非胆碱能 和胆碱能均主要来自内侧隔核Q)I+腹侧海马各亚区)SLRTSLGUSLI和齿状回门区或SLE+都主要接受内侧隔核的纤维传入B但 胆碱能和非胆碱能比例不同BSLRTSLGUSLI和SLE来自内侧隔核M斜角带垂直部的投射均主要是非胆碱能的B且主要来自内 侧隔核B其胆碱能几乎等量来自内侧隔核和斜角带垂直部Q内侧隔核M斜角带复合体@腹侧海马亚区胆碱能和非胆碱能投射比例 的不同B为认识内侧隔核M斜角带复合体@海马通路对记忆环路中的海马调节机制B提供了新的形态学依据Q
Resumo:
黄花蒿精油对米象、玉米象、绿豆象和蚕豆象等 4种仓库害虫具有很强的熏杀活性 ,其甲醇和乙醇提取物对小菜蛾、菜青虫、大菜粉蝶、银纹夜蛾和斜纹夜蛾幼虫也具有一定的杀虫活性。
Resumo:
通过实验现场采样及室内测试方法,对复合垂直流人工湿地-池塘养殖复合系统中的物理、化学、生物和生化指标进行因子分析,并在养殖周期、日变化上对碱性磷酸酶活性进行了研究。结果表明,循环池的水质明显好于对照池,影响系统水质的主要因子在循环池和对照池中是不同的,其中循环池主要影响因子是生物指标细菌,对照池主要影响因子是氮、磷等化学因子;碱性磷酸酶存在明显的日变化规律,20时达到一天的最高;循环池和对照池的碱性磷酸酶活性以及叶绿素a含量等方面存在显著性差异,其中循环池碱性磷酸酶的日变化范围是2.81~6.83mmol