铁路路基工后沉降的数值仿真分析

铁路路基是一种由多种材料组成的组合体,对其变形分析也是一个高度非线性问题.采用高级非线性有限元软件MSC.Marc模拟分析了路基的沉降变形情况,仿真结果与路基实际沉降变形趋势相一致.     

Materials for optical information processing

The goal for optical information processing is to use the unique characteristics of light which are not readily achieved with electronic devices, namely, ultrahigh speed (picoseconds), a high degree of parallelism (image processing), and conductor-free interconnection. The requirements of the nonlinear materials to perform such functions, using all-optical interactions, are discussed and the limitations of the nonlinear mechanisms are outlined.     

多元图论非线性映射分类及其在小麦研究中的应用

本文给出了一种将多元图论及非线性映射方法结合起来对样品进行分类研究的方法一多元图论非线性映射分类法,并应用此法探讨了41个小麦材料的最小支撑树及其在二维平面上的非线性映射分类图,与系统聚类法及主成分方法聚类相比,本方法有其特殊的优越性,能更直观形象而又比较准确地在二维平面上反映多维空间中小麦样品点的全部整体的亲疏关系,从而得到二维平面上直观的分类图。对遗传育种亲本选配研究有一定参考价值,对农业科学及其它领域的多元聚类问题都有参考意义。     

全光纤电流互感器的建模与仿真技术研究

在全光纤电流互感器物理模型的基础上,推导出了非线性动态模型,经过等效近似,建立了全光纤电流互感器的线性离散模型,并根据该模型对互感器的动态特性进行了仿真分析.同时,根据全光纤电流互感器的噪声特征建立了随机噪声模型,然后用不同的随机过程来模拟发生各种随机噪声.仿真结果表明：所建模型是合理的,模拟产生的随机噪声能够反映光纤电流互感器中噪声的统计特性.     

Optical materials

Optical technologies are becoming increasingly important in areas that were traditionally the domain of electronics. This trend is likely to continue into the foreseeable future with optics and electronics being integral, mutually compatible components of systems for consumer markets, industry, and defense. The basis of this progress is the development of materials that have the required purity, physical properties, and optical quality; glass fibers for optical transmission, semiconductors for lasers and detectors, and nonlinear materials for optical switching are examples. In this article, some of the materials of choice for a variety of applications are described and the frontiers of materials research for new areas of opportunity are discussed. Particular emphasis is placed on optical materials for the transmission and processing of information.     

一种求解不等式约束优化问题的光滑化算法

利用光滑函数建立了不等式约束优化问题KT条件的一个扰动方程组,提出了一个新的内点型算法. 该算法在有限步终止时当前迭代点即为优化问题的一个精确稳定点. 在一定条件下算法具有全局收敛性,数值试验表明该算法是有效的.     

All-optical nonlinearities in organics

Recognition that organic solids possess some of the largest all-optical nonlinearities of all known materials has resulted in an interdisciplinary effort directed at both the basic understanding and exploitation of these effects. Parallel efforts on ionrganic semiconductors have already reached a mature stage whereby the origin of the effects, together with the prospects for device applications, are well known and appreciated. In this article, a unified picture of nonlinear optical phenomena in both classes of materials is presented. The specific implications for organic-based optical devices are discussed.     

Polar orientation of dyes in robust multilayers by zirconium phosphate-phosphonate interlayers

Polar orientation of molecules in solids leads to materials with potentially useful properties such as nonlinear optical and electrooptical activity, electrochromism, and pyroelectricity. A simple self-assembly procedure for preparing such materials is introduced that yields multiple polar dye monolayers on solid surfaces joined by zirconium phosphate-phosphonate interlayers. Second harmonic generation (SHG) shows that the multilayers have polar order that does not decrease with increasing numbers (up to a large number) of monolayers in the film. The inorganic interlayers, as determined by SHG, impart excellent orientational stability to the dye molecules, with the onset of orientational randomization above 150 degrees C.     

Electrically controlled nonlinear generation of light with plasmonics

Plasmonics provides a route to develop ultracompact optical devices on a chip by using extreme light concentration and the ability to perform simultaneous electrical and optical functions. These properties also make plasmonics an ideal candidate for dynamically controlling nonlinear optical interactions at the nanoscale. We demonstrate electrically tunable harmonic generation of light from a plasmonic nanocavity filled with a nonlinear medium. The metals that define the cavity also serve as electrodes that can generate high direct current electric fields across the nonlinear material. A fundamental wave at 1.56 micrometers was frequency doubled and modulated in intensity by applying a moderate external voltage to the electrodes, yielding a voltage-dependent nonlinear generation with a normalized magnitude of ~7% per volt.     

偶氮苯衍生物的光致变色性及其应用

综述了一些偶氮苯衍生物(ABD)的结构类型、变色特性、变色机理以及在光色材料科学领域如液晶聚合物、自组装单分子膜、非线性光学材料等方面的研究进展及存在的困难。     

务川仡佬族苗族自治县中药材产业发展建议

结合务川县中药材产业统计数据,对务川县中药材产业现状进行了介绍,立足产业现状,分析当前务川县中药材产业发展中的优势和存在的问题,并提出快速发展务川县中药材产业发展的对策建议。     

河北省农资连锁经营的现状及发展探索

阐述了农资连锁经营的内涵及意义;以政策支持、模式、规模为切入点,分析了河北省农资连锁经营现状,并对其未来发展方向进行了探索。     

秸秆原料沼液预处理技术研究分析及评价

秸秆原料的结构组成复杂，阻碍了其有效厌氧消化。沼液预处理技术能有效改变秸秆类原料结构，促进其厌氧消化。本文在介绍秸秆类原料预处理方法的基础上，对秸秆原料沼液预处理技术研究现状进行了分析，总结了目前秸秆原料沼液预处理技术的处理对象、方法、评价指标等，同时针对现状分析评价了目前秸秆类原料沼液预处理技术存在的问题和不足，并进行了展望，以期为该技术的推广应用提供参考。     

青钱柳嫩枝扦插育苗的研究

以青钱柳当年生嫩枝为插穗,分别对不同的育苗基质、不同种类和浓度的生根剂及处理时间进行青钱柳插条生根效应的研究。试验结果表明:扦插时间以5月中旬至6月中旬为最佳时间;扦插基质以蛭石 珍珠岩最合适;生根剂以SJc l对青钱柳扦插苗生根有明显的促进作用,SJc l浓度为250 mg/L,浸泡时间3 h时生根率达最高,生根率为45.6%;健壮当年生的半木质化枝条是青钱柳理想的扦插材料。     

紫外光固化聚硅氧烷材料的研究进展

文章对紫外光(Ultraviolet Rays,UV)固化聚硅氧烷体系的种类及其在涂料、防黏隔离材料和有机-无机杂化材料等中的应用进行了综述,并对其研究方向进行了展望.     

Linking models of polymerization and dynamics to predict branched polymer structure and flow

We present a predictive scheme connecting the topological structure of highly branched entangled polymers, with industrial-level complexity, to the emergent viscoelasticity of the polymer melt. The scheme is able to calculate the linear and nonlinear viscoelasticity of a stochastically branched "high-pressure free radical" polymer melt as a function of the chemical kinetics of its formation. The method combines numerical simulation of polymerization with the tube/entanglement physics of polymer dynamics extended to fully nonlinear response. We compare calculations for a series of low-density polyethylenes with experiments on structural and viscoelastic properties. The method provides a window onto the molecular processes responsible for the optimized rheology of these melts, connecting fundamental science to process in complex flow, and opens up the in silico design of new materials.     

非线性植被-侵蚀动力学模型初探

植被-侵蚀动力学是一门研究流域植被与侵蚀在人类活动影响下演变规律的边缘学科.现有植被-侵蚀动力学模型是基于指数增长模型建立的,在多数时段具有较高精度,但在高植被覆盖度（V）、低侵蚀率（E）,以及低V高E等特殊时段精度略差.为提高模型模拟精度并扩大其适用范围,该文提出了一种基于Logistic模型的非线性模型,并将两种模型应用于北京西山地区、宁夏西吉黄家二岔、陕西长武王东沟以及广东惠州上杨试验站等小流域植被及侵蚀演变过程的模拟.结果表明,非线性模型在一般时段的模拟精度与线性模型相当,而在特殊时段,前者的精度明显高于后者.但是非线性模型求解复杂,引入的两个新参数需深入研究确定.同时,由非线性模型推出的植被-侵蚀状态图形式复杂且不完全符合实际情况,不如由线性模型得到的植被-侵蚀状态图简单实用.非线性模型还有待于进一步地修正和完善.      

基于Web教材管理系统的开发

首先说明目前教材征订流程,以此分析当前高校教材征订流程的缺点,然后设计了一个新的教材征订流程,通过将现有的流程分解为教材信息库维护及教材征订两个流程,解决现有流程所出现的问题.文章最后对新的流程进行讨论,并介绍了系统使用的情况.     

高校音乐资料的管理趋向分析

针对当今信息时代信息传播和管理现状、音乐资料的特殊性以及信息化管理模式所具有的优越性三个方面进行分析,得出高校音乐资料的管理趋向是进行信息化管理模式。     

我国家具材料的发展趋势探讨

通过对我国家具材料使用现状的调查,分析了大众对家具所用材料的意识及追求,预测未来家具材料的发展趋势,对家具材料的发展提出了建议.