Magnetic properties of highroad-side pine tree leaves in Beijing and their environmental significance

This is a report on magnetic properties of highroad-side tree (Pinus pumila Regel) leaves collected along an expressway linking Beijing City and the Capital International Airport and further focus on their environmental contributions. A series of rock magnetic experiments show that the primary mag-netic mineral of leaf samples was identified to be magnetite,in the pseudo-single domain (PSD) grain size range 0.2―5.0 μm. On the other hand,magnet-ite concentration and grain size in leaves are ascer-tained to decrease with increasing of sampling dis-tance to highroad asphalt surface,suggesting that high magnetic response to traffic pollution is localized within a distance of some two meters away from highroad asphalt surface. Although magnetic suscep-tibility is ordinarily regarded as a simple,rapid and low-cost method for monitoring traffic pollution,saturation isothermal remanent magnetization (SIRM) can be treated as a valid proxy for monitoring air par-ticulate matter (PM) when samples are magnetically weak. It is believed that a synthetic rock magnetic study is an effective method for determining concen-tration and grain size of ferromagnets in the atmos-pheric PM,and then it should be a rapid and feasible technique for monitoring atmospheric pollution.     

移动自组网中基于区域的多路路由算法

提出了一种适用于移动自组网的基于区城的多路路由算法。该算法将路由发现控制在一个预定区城内，不仅大量减少路由控制开销，而且确保最优路由。分析和仿真表明，选用合适的多径选取策略，在高移动、高动态网络环境下，该算法在路由开销、TCP吞吐量以及时延方面都有一定的提高。     

模糊评价法在东湖水环境质量评价中的应用

介绍了模糊数学评价法,以清徐东湖水质评价为例,说明了模糊数学评价方法在环境质量评价中的应用。     

A Poem of Exotic Tragic Beauty ——Appreciation of The Road Not Taken by Robert Frost

The Road Not Taken is one of the best known poems by Robert Frost.Simple and beautiful in form,it is profound in meaning.It reflects the tragedy of human beings as a whole and also the personal tragedy of the poet himself,and as a consequence,it is tinted with an exotic sense of tragic beauty.     

一般Hamilton图的DNA解

本文给出了一种用DNA化学反应的方法解决一般Hamilton图的问题。     

下一代分组交换网的SDL协议

SDL协议是一种新型的数据链路装帧协议 ,主要针对点对点信道中不定长或定长的分组。它对ATM中的 HEC装帧机制予以扩展 ,将之用于不定长数据报。SDL实现容易 ,特别适合于在基于波分复用的高速光纤传送链路中应用。 SDL中也易于实现下一代多业务光纤分组网络所需的很多 OAM& P功能。在高数据速率的环境下 ,与 ATM和 POS相比 ,SDL是一种颇具吸引力的方案。主要阐述了 SDL的成帧、数据链路的同步过程及性能评估     

大跨径钢桥面环氧沥青混凝土铺装研究

在国内外系统研究环氧沥青混凝土铺装材料组成设计，混合料材料特性和路用性能的基础上，采用复合梁疲功试验研究环氧沥青混凝土桥面铺装的抗疲劳性能等，研究表明，环氧沥青混凝土是较好的铺装材料，研究成果已应用于南京长江第二大桥钢桥面铺装中。     

南湖风景区开发过程中的水土流失及其防治对策

为了保护南湖水质，防止因环南湖游路建设造成的水土流失而引起南湖水质恶化，运用水土流失方程对环南湖游路建设的水土流失侵蚀强度及 流失量进行分析计算。结果表明：环南湖路的建设将造成一定量的水土流失，流失量可达904．15t/a，采用水土流失防治措施，如改进施工方法将大量减水土流失量，削减量可达867．44t/a。这为南湖风景区开发建设过程中的环境保护管理提供了参考依据。     

功率集成光激MOS控制交流多路开关模拟设计

介绍了一种新型功率集成光激MOS控制多路开关，它由双向晶闸管，MOS器件，光电器件组成。此开关通过光电转换来实现强电与弱电之间的隔离，可工作在交流状态，其通态压降低，约在1．5－3V之间，并对其阻断特性，电流特性，开关特性进行了全面的模糊分析，此开关适用于开发各种电源开关产品。     

网络最短路问题的极小代数解法

定义二个运算⊕,⊙,构成一个极小代数｛R,⊕,⊙｝,在其上定义矩阵运算,将网络最短路问题的求解转化为矩阵的乘积。该算法概念清晰明了,算法简明。