基于结构层贡献率的沥青路面抗车辙措施

采用环道试验及德国汉堡车辙试验方法,研究在中面层使用改性沥青对路面结构和组合结构抗车辙性能的影响,包括对结构层贡献率和对沥青层剪切流动变形的影响;探讨在中面层添加纤维对路面结构抗车辙能力的影响.研究结果表明:中面层使用改性沥青,能提高路面结构的整体抗车辙性能;使剪切流动变形由95.2%下降至84.4%;中面层变形贡献率达到60%以上,应该重视提高中面层的抗车辙能力;对于中面层采用普通沥青的结构,在中面层添加纤维可明显减少整个结构车辙深度,但对于中面层已采用改性沥青的结构,添加纤维减少车辙的效果不明显.     

一类Turing模型的Hopf分歧分析

讨论Turing模型的三阶泰勒展开式的常微形式:u′=αu(1-r1v2)+v(1-r2u),t0,v′=v(β+αr1uv)+u(γ+r2v),t0,u(0)=u0,v(0)=v0,其中-1β0,0α1,r10,r1、r2分别是三次项、二次项的系数.通过考虑平衡解的稳定性,判断Hopf分歧发生的条件和分歧方向.     

一种环境激励下斜拉桥模型损伤识别方法

虚拟脉冲响应函数可表征环境激励下结构系统固有的动力特性,但桥梁试验模型空间变异的模糊性和测量过程中环境激励的随机性,使得虚拟脉冲响应函数同时具有随机不确定性和模糊不确定性,适用于随机-模糊统计原理处理.而Hilbert-Huang变换(HHT)是一种新的适用于非线性、非平稳信号且具有自适应性的数据处理方法.提出了基于HHT与虚拟脉冲响应函数随机模糊均值的结构损伤识别方法,并将4个Hilbert边际谱能量指标应用到室内斜拉桥模型的损伤识别中.结果表明:主梁损伤前后4种能量指标都发生了变化,且体现出相似的规律性,准确指示了较大程度损伤的损伤位置和程度,为大型桥梁结构在线监测提供了一种方法.     

压力下半导体GaAs的电子表面态

使用插值拟合近似获得晶格常数、带隙随压力的解析表示，采用变分法研究了流体静力学压力对半导体GaAs电子本征表面态的影响，数值结果表明，随压力增加电子表面态能级明显向上移动，且电子趋近表面。     

海子抒情诗中“秋”意象解析

海子诗歌意象丰富，意蕴深厚，极具艺术张力，例如“秋”意象。本文从三方面论述海子抒情诗中“秋”意象。首先，“秋”象征丰收而荒凉的人世；其次，论述“秋”的感伤；最后，“秋”是幻象丛生的国度。     

云南松优良家系超级苗选择研究

 为探讨云南松苗期选择的依据和标准,加速现有优良遗传资源的早期、短期开发利用,对20个家系1 a苗木的生长性状差异进行了分析.结果表明:家系之间以及同一家系不同个体之间的苗高、地径生长量存在极显著差异,且苗高生长量差异明显大于地径生长量.因此,以各家系平均高生长量加1倍标准差为最低标准进行超级苗选择,在11 331株育种群体中共选超级苗1 629株,入选率为14.3%.其中,超级苗平均高度为8.92 cm,比育种群体平均高度增加35.9%;超级苗平均地径为3.50 mm,比育种群体平均地径增加3.6%.     

Analysis of Ultra - wideband Wireless Communications Technology Development

超宽带无线通信技术是一种具有高速、低成本和低能耗特点的无线通信技术,该技术的发展对于解决短距离内数据高速度无线传输具有重要的意义.文章拟从概念、特点、发展等方面对之进行论述.     

Design of the signal processor for an ionospheric sounding system

On the basis of the analysis of the system sounding principle, this paper introduced a new type of ionospheric oblique backscattering sound system, which is based on the pseudo- random noise phase modulated pulse compression. According to the high requirements of real-time and a large amount of computation and echo characteristics, a high-speed real-time signal processing system was established and the design of system hardware and software was focused on. The sounding results indicate that the system is equipped to handle the data fast and has a high degree of software features. It is of great significance for the realization of fast, real-time ionospheric sounding means.      

我国电子政务的发展与研究

目前,电子政务已成为世界许多国家和地区政府追求的目标和关注的焦点,我国的电子政务同样也得到了党和国家的高度重视,并成为国家信息化建设中极为重要的组成部分。本为首先介绍了我国电子政务的发展历程,然后经过深入研究总结出我国电子政务存在的问题,并提出相应的解决措施。     

Coordinating production and recycling decisions with stochastic demand and return

In this paper, the joint production and recycling problem is investigated for a hybrid manufacturing and remanufacturing system where brand-new products are produced in the manufacturing plant and recycled products are remanufactured into as-new products in the remanufacturing facility. Both the brand-new products and remanufactured products are used to satisfy customer demands. Returns of used products that are recycled from customers are assumed to be stochastic and nonlinearly price-dependent. A mathematical model is proposed to maximize the overall profit of the system through simultaneously optimizing the production and recycling decisions, subject to two capacity constraints — the manufacturing capacity and the remanufacturing capacity. Based on Lagrangian relaxation method, subgradient algorithm and heuristic algorithm, a solution approach is developed to solve the problem. A representative example is presented to illustrate the system, and managerial analysis indicates that the uncertainties in demand and return have much influence on the production and recycling policy. In addition, twenty randomly produced examples are solved, and computational results show that the solution approach can obtain very good solutions for all examples in reasonable time.