强双折射光纤中暗孤子的传输特性研究

从光纤双折射参量、背景光宽度、孤子脉冲宽度三方面探讨暗孤子在双折射光纤中远距离传输特性研究表明:相对于亮孤子,暗孤子对光纤双折射的自适应能力较弱;背景光宽度越大,暗脉冲与背景光对比度越好,暗孤子越能保持原来黑孤子状态;暗孤子脉冲宽度越大,偏振脉冲之间的差分群时延越大,诱导的灰孤子震荡结构越明显,越不利于暗孤子远距离传输.     

DNA damage induced by laser-hematoporphyrin derivative

Irradiation caused DNA single-strand breaks in S180 cells in the presence oflaser-hematoporphyrin derivative(HPD).The number of single strand breaks was 3.69 ×10~(10)break dolton~(-1).The analysis of base composition of DNA showed that the effect of laser-HPDirradiation on guanine was the highest,being 5-12 times as high as those of the three others(adenine,cytosine and thymine).It was different from the nature of DNA damage caused by γ-ray irradiation.     

粘土空心砖的热物理性能分析

本文提出热物理性能应作为粘土空心砖的主要性能指标，并对粘土空心砖的传热过程和热导率进行了分析。     

高能不等核碰撞和弛豫时间的相对论动力论方程描述

本文用相对论动力论方程描述高能重离子碰撞时空演化,并用它分析在200A GeV的¹⁶O束流和³²S束流下,于快度中心区的末态粒子快度分布,确定了不同系统的弛豫时间.     

中药土鳖虫溶栓成分的分离纯化研究

对土鳖虫水浸醇沉提取物2号样品进行了离子交换柱层析，得组分Ⅰ、Ⅱ、Ⅲ。实验结果表明，组分Ⅲ的溶栓活性明显高于组分Ⅰ和组分Ⅱ，其蛋白质占量为88．9％，分子量约为38，018，效价为313UK／mg，比活力为352UK／mg蛋白。将组分Ⅲ再进行凝胶过滤柱层析，得组分Ⅳ、Ⅴ、Ⅵ。组分Ⅵ的生物活性高于组分Ⅳ和组分Ⅴ，蛋白质含量为89．3％，电泳呈现两条带，分子量约为34，623和39，811，效价为77UK／mg，比活力为86UK／mg蛋白。将组分Ⅵ进行反相高效液相色谱柱层析，收集保留时间为17min的洗脱峰，得到土鳖虫纯蛋白质，呈白色絮状，极易溶于水。再一次用反相高效液相色谱检查其纯度，保留时间为17．073min．无杂质峰。纤溶活性实验结果表明，组分Ⅵ既有直接降解纤维蛋白的作用，同时也有纤溶酶原激活剂样作用。     

图论在检修维护工期规划中的应用——关键路线法的证明与计算

本文证明出,在图G上一种新的求关键路线方法。该法便于编制程序与上机计算。通过工程实例检验证该实法简便及运算速度快。     

大气压微波等离子体炬的仿真设计与实验

设计了一个低成本、高稳定性的基于BJ22矩形波导的微波等离子体炬源。整个系统由1～10 kW主频2.45 GHz的磁控管微波功率源、环形器、调谐器和微波反应腔体组成。通过特殊设计的调谐装置,在气体喷嘴处产生高幅值的电场强度,使工作气体电离形成大气压开放式微波等离子体炬。对影响电场强度的几个关键因素进行了仿真,得出各个参数对场强的影响规律;根据仿真参数设计了微波反应腔体,该系统可以在大气压下激发和维持开放的稳定氩气、氦气、氮气和空气等离子体炬。对等离子体炬的基本特性和基本参数进行了研究,验证了设计参数的正确性,讨论了其可扩展性及潜在的工业应用。     

Generation of picosecond soliton pulses with tunable repetition rate by modulational instability

Picosecond soliton pulse train has been obtained from a passively mode locked erbium-doped ring fiber laser. The passive mode-locking mechanism that is at play in this laser relies on the modulational instability (MI) theory. By accurately adjusting the polarization setting of the circulating cavity light, the repetition rate can be tuned from 58 to 114 GHz. Theoretical explanations has also been given.     

Hopf bifurcation analysis of a density predator-prey model with crowley-martin functional response and two time delays

In this paper, a delayed density dependent predator-prey model with Crowley-Martin functional response and two time delays for the predator is considered. By analyzing the corresponding characteristic equations, the local stability of each of the feasible equilibria of the system is addressed and the existence of Hopf bifurcation at the coexistence equilibrium is established. With the help of normal form method and center manifold theorem, some explicit formulas determining the direction of Hopf bifurcation and the stability of bifurcating period solutions are derived. Finally, numerical simulations are given to illustrate the theoretical results.     

含步长加速变异算子的微粒群算法

提出了含步长加速变异算子的微粒群算法和它的一种变体———全局最优位置的步长加速变异微粒群算法,通过测试函数的对比分析,说明了这两种含变异算子的微粒群算法具有较好的收敛速度和稳定性.