饮用水二次污染水质控制模拟研究

通过数学模拟及实验研究,给出二次污染水质模型参数反应动力学速率常数k、CODMn最大生成潜能ρmax的估计值,分析了水在管网流动的过程中污染物迁移转化过程,提出不同管材的极限水力停留时间,为输配水管网系统安全运营提供技术依据.     

单个粗糙裂隙中水流及溶质运移研究进展

文章回顾了有关单个粗糙裂隙中水流和溶质运移的理论、实验研究和数值模拟的成果,重点评述了对裂隙结构面粗糙度的分形特征、粗糙裂隙中描述水流的模型和溶质运移的弥散系数和穿透曲线,并对反映单个粗糙裂隙中水流特征的“局部立方定理“适用条件和溶质运移所呈现的“非费克”运移机理作了初步分析,在此基础上探讨了今后的研究趋势。     

Structural aspects of Golgi function

Since its discovery, the Golgi complex has attracted the attention of cell biologists because of its fashionable morphology and central position within the secretory system of the cell. Here, we discuss how the three-dimensional architecture of the Golgi complex relates to its multiple functions in protein sorting and processing, and how an analysis of the morphology of the Golgi complex can help to provide an understanding of the mechanisms involved in transport through this unique organelle.     

The ABC transporter structure and mechanism: perspectives on recent research

ATP-binding cassette (ABC) transporters are multidomain integral membrane proteins that utilise the energy of ATP hydrolysis to translocate solutes across cellular membranes in all phyla. ABC transporters form one of the largest of all protein families and are central to many important biomedical phenomena, including resistance of cancers and pathogenic microbes to drugs. Elucidation of the structure and mechanism of ABC transporters is essential to the rational design of agents to control their function. While a wealth of high-resolution structures of ABC proteins have been produced in recent years, many fundamental questions regarding the proteins mechanism remain unanswered. In this review, we examine the recent structural data concerning ABC transporters and related proteins in the light of other experimental and theoretical data, and discuss these data in relation to current ideas concerning the transporters molecular mechanism.Received 29 August 2003; received after revision 19 November 2003; accepted 28 November 2003     

渗透系数空间变异性对低渗透地层中地下水溶质运移的影响

以天津市北大港水库为例,通过野外勘探、现场取样、室内试验、数值模拟等方法,研究水库库底地层渗透系数空间变异性对地下水溶质运移的影响。结果表明:北大港水库库底地层渗透系数较小,且呈现出较强的空间变异性;地下水流通量随地层渗透系数空间变异程度的增加而增大,渗透系数均值对水流通量的影响大于其标准差;渗透系数均值越大,在地下水流的抑制作用下,溶质运移程度越弱,而渗透系数空间变异性越强,地下水流的抑制作用相对越弱,溶质运移程度越强。     

城市公交换乘查询系统的优化枚举算法研究与应用

该文针对目前我国城市公交查询系统存在的不足,提出了一种便于乘客进行路线选择的优化枚举算法,并探讨了以换乘次数最少为目标的公交查询方案。对n次公交换乘算法进行改进,引入紧邻站点和站站快表,提高公交查询系统的实用性和查询效率,从而吸引出行者优先选择公交车出行方式。     

一种多粒度传送网中的能量感知自适应疏导机制

在多粒度传送网中,可以通过业务量疏导将大量业务数据疏导进光层,从而有效提高带宽利用率和降低能耗。基于此,首先描述了一种能量感知的网络模型,并根据多粒度传送网的实际工作情况,引入网络行为的概念,分析了多粒度传送网的能耗情况。然后提出了能量感知自适应IP层优先疏导算法,引入了"旁观节点"的概念,旨在适当的时刻将网络中度数较低的节点调整为"旁观节点"状态,以使网络重载时新到来的业务能够不经过这样的节点。最后对所提出的算法进行了仿真实现,仿真结果表明所提算法与基准算法相比有明显的优势。     

我国高效运输技术与装备领域创新取得一系列标志性成果

随着我国经济社会的不断发展,交通运输业日益成为影响国民经济持续发展的因素.为此,2006年国家颁布了《国家中长期科技和技术发展规划纲要（2006-2020年）》（以下简称《纲要》）,将“交通运输业”列为重点领域,其中“高效运输技术与装备”是交通运输业的6个优先主题之一.围绕《纲要》对交通运输业领域科技工作的政策要求,国家各部位、各地方、相关企业积极响应,并就高效运输技术与装备主题进行了政策发布,机车列车、轨道交通及船舶方面进行了系统的部署.数年来,我国高效运输技术与装备业已取得显著成效.     

奇异迁移算子一阶余项的弱紧性

本文对一类具周期边界条件、连续能量、各向异性的奇异迁移方程进行了讨论。在L1空间,证明了奇异迁移算子Ak相应的奇异迁移半群V(t)(t≥0)的Dyson-Phillips展开式的一阶余项R1(t)的弱紧性。     

Water Transport Models of Moisture Absorption and Sweat Discharge Yarns

An important property of moisture absorption and sweat discharge yarns is their water transport property. In the paper, two water transport models of moisture absorption and sweat discharge yarns were developed to investigate the influence factors on their wicking rate. In parallel Column Pores Model, wicking rate is determined by the equivalent capillary radius R and length of the capillary tube L. In Pellets Accumulation Model, wicking rate is decided by the capillary radius r and length of the fiber unit assemble L0.