含裂纹轴的有限元分析模型

通过对产生裂纹的圆轴局部的特殊处理,导出含裂纹单元的应力强度因子,建立了该单元刚度矩阵,进而建立了有限元分析的整体平衡方程。     

终端区交通态势识别研究

终端区交通态势日益拥挤,严重制约了航空运输业的快速健康发展。为了科学评估空中交通状态,提高空域资源的利用率,对终端区交通态势进行了研究。提取影响终端区的属性指标,运用模糊C-均值聚类(FCM)对数据进行分类离散化,采用粗糙集理论分析各属性的权重,并结合模糊关系矩阵构建终端区交通态势识别模型。采用FCM和FCM-粗糙集两种识别方法对终端区交通态势进行识别。结果表明FCM-粗糙集模型既可避免人为因素干扰,还可解决数据多属性冗余问题,使交通状态判断更加准确可信;终端区交通态势分四类时,效果最好。该模型为终端区交通态势识别提供了新的研究方法。     

基于监视数据修正的航空器飞行轨迹推算模型

飞行轨迹推算是空中交通流量管理的一个重要研究内容。在传统飞行轨迹推算方法基础上,针对航空器飞行路径的不确定性,构造了基于监视数据动态修正的航空器飞行轨迹推算模型。该模型综合航空器飞行性能和飞行计划、实时监视信息对航空器飞行轨迹、姿态进行推算。利用真实飞行轨迹进行验证,结果表明:本文模型推算的位置、高度信息更接近实际轨迹,并且符合实际飞行原则和空域使用规则,具有一定的参考价值和实用性。     

城市短历时暴雨强度公式参数率定

根据实测暴雨资料,用以最小二乘法为准则的高斯－牛顿迭代法,直接求解暴雨公式中的参数,算法简单,可以减少中间环节带来的计算误差,提高参数的精度．     

河南省少年儿童健康风险因素水平的现状调查

本以国家教委重点课题《义务教育阶段学校健康教育模械研究》总课题组设计的“青少年健康风险因素水平”问卷为依据,对河南省的郑州、新乡两座城市及郊区的６８６名中小学生进行了抽样调查。     

激光诱导荧光强度与被测样品温度的关系

研究一种应用较广的油的激光诱导荧光强度（ＬＩＦ）与其本身温度之间的关系。用输出波长为３５５ｎｍ的三倍频Ｎｄ：ＹＡＧ激光器做发光源,用多通道光谱分析仪妆收探测。用ＪＫＹ－１型控温仪水浴的方法控制没的温度,测量不同温度下油的激光诱导荧光强度,从量物理和荧光产生的机理入手对实验进行理论分析,结果表明,在发射光谱稳定不变的民政部下,荧光强度随温度的升高耐减弱。     

扩展准单色光杨氏干涉条纹的光强分布

用三种方法讨论部分相干光理论中,在既考虑光源线度又考虑谱线宽度情况下,扩展准单色光杨氏干涉条纹的光强分布。     

Attracted by the same sex,or repelled by the opposite sex?——Sexual segregation in P

Sexual segregation behavior has attracted deep interest of zoologists in recent years. People have put forward many hypotheses to explain the phenomenon. We recommended two indices for measuring the intensity of aggregation and sexual segregation in animals, and applied those measurements to the study of aggregation and sexual segregation in free-ranging Pere David's deer. We quantified the aggregation and segregation behavior with those methods and compared the intensities of sexual segregation in different seasons with statistic means. At the same time, the Nutritional Strategy Hypothesis, the Social-factor Hypothesis and Reproductive Strategy Hypothesis were tested in the study. We discovered that aggregation in free ranging Pere David's deer was high in winter but low in summer. Sexual segregation in free ranging Pere Danid's deer is caused by the reproductive strategy of different sexes, the highest degree of sexual segregation was found in the breeding season not the non-breeding season in the free ranging Pere David's deer.     

ATM网中的ABR业务及其拥塞控制和拥塞检测

ABR业务是ATM网络提供的新型业务 ,它的特点是能充分利用网络资源 ,同时又采用基于速率的闭环拥塞控制机制 ,从而保证了服务质量 .在控制机制中选择良好的检测方法又保证了控制的有效性     

Threshold effect of incident light intensity on the photorefractive light-induced scattering in double-doped lithium niobate crystals and its application

The formation mechanism of fanning noise in lithium niobate crystal is theoretically studied using the multi-wave mixing model. The threshold effect of incident light intensity for the photorefractive light-induced scattering in double doped lithium niobate crystal is explained by combining the multi-wave mixing model with the rwo-photorefrac-tive-sensitive-center model for single charge-carrier. Light amplification competition between the fanning noise and the signal beam in doped lithium niobate crystals is also studied. The existence of optimum photovoltaic field and optimum pump intensity is predicted theoretically.