结合虚拟迭代技术的整车级道路模拟试验方法

目的 提出一种基于试验场实采道路载荷谱,通过虚拟迭代技术修正台架试验动力学模型,从而实现多系统的“整车级”道路模拟试验的方法。方法 围绕台架关联试验场坏路,基于累积损伤模型、四点雨流计数法和模态分析展开研究,通过道路载荷谱的采集,预处理、压缩,在台架上复现零部件于整车上的运动姿态、失效形式与模态振型。最终完成以整车道路载荷谱为期望信号的台架迭代,以虚拟迭代为指导的模型修正,建立车辆道路时序信号与试验台架加载谱的相关性转化映射关系,执行基于液压伺服七轴试验台的多轴耐久试验,并实现以计算机模态分析、疲劳分析为指导的联合验证。结果 各零部件的试验结果为合格,与试验场一致。实现了多系统的同时验证,准确复现待测系统的运动姿态、失效形式及模态信号。结论 该试验方法建立起了整车级道路模拟试验标准,即通过虚拟迭代试验技术调整台架试验的动力学模型,为多系统道路模拟试验迭代不收敛的情况提出了解决方案。     

浅析攀枝花市酸雨污染特征及成因

利用1996年至2000年大气降水监测数据，对攀枝花市酸雨污染特征及成因进行了分析。结果表明：攀枝花市大气降水酸化除受本地污染源影响外，还受地理环境、气候以及碱性物质等因素的影响。     

济南市城市扩展与城市暴雨洪灾

阐述了济南市城市扩展历程和城市暴雨洪灾概况,分析了济南市城市暴雨洪灾的成因.研究结果表明,浅盆地形和多暴雨的气候条件是济南市城市暴雨洪灾的自然致灾因素,而城市扩展后,城市雨岛效应增加了市区暴雨出现的频率与强度,城市外部排水变为内部排水,对下垫面性质及自然沟道、洼地的改造使城市洪量增大,滞时减小等,加剧了济南市城市暴雨洪灾的量级和频度.为应对严峻的城市暴雨洪灾,提出了排蓄结合的应对措施.即从源头上减少流经城区的洪水量,加强排水系统的整治,建立健全雨情、水情遥测网和城市防洪调度决策支持系统.     

IMPLEMENTATION OF BIORETENTION SYSTEMS: A WISCONSIN CASE STUDY1

ABSTRACT: The implementation of various bioretention systems was analyzed, including rain gardens, vegetated swales, trenches, and infiltration basins in the St. Francis subdivision, Cross Plains, Wisconsin. Through the examination of archival data and interviews with key participants, it was found that although regulatory and political pressures encouraged the inclusion of bioretention, current standards for storm water management prevailed. The developers had to meet both existing requirements and anticipated rules requiring infiltration. As a result, bioretention systems simply supplemented, rather than replaced, traditional storm water practices. The confusion surrounding dual standards contributed to substantial delays in the negotiations among relevant stakeholders in the watershed. It is concluded that the St. Francis subdivision serves as both a cautionary tale and a bioretention success story. As a caution, this situation demonstrates the need for careful review and refinement of existing storm water ordinances to incorporate water quality improvement technologies, such as bioretention. The demonstrated success of the St. Francis development, however, is that it became a positive prototype for best management storm water practices elsewhere in the region. In addition, the water quality monitoring data from the site has contributed to development of a new county ordinance, the first in Wisconsin to address both quantity and quality of storm water runoff.     

江苏省春季连阴雨和太平洋海温的响应关系研究

对太平洋海温和江苏省春季连阴雨进行相关普查,通过非线性最优化因子处理方法对太平洋海温因子进行变换,确定高相关区。结果表明:江苏春季连阴雨的发生与太平洋海温的变化显著相关,从相关区域的大小看,下半年各海区温度变化与江苏次年春季连阴雨的相互关系更为密切,苏南和江淮地区的显著性要优于淮北;而从海区的位置上看,淮北连阴雨的相关海区在冬春季主要集中在高纬地区,夏季在低纬地区;其它地区的相关海区则从春季开始由高纬度向低纬度地区过渡。通过t检验分析了ENSO现象对当年和次年的江苏省春季连阴雨发生的次数的影响,发现EI Nino事件对当年和次年的江苏春季连阴雨发生次数均呈正效应,La Nina事件对当年江苏春季连阴雨无显著影响,与次年的春季连阴雨呈负效应。     

江苏省近47年来的梅雨特征及灾害影响

利用江苏省气象台1954～2000年的梅雨期降水资料，采用趋势分析方法，对江苏省的梅雨变化特征进行了分析研究。结果表明：近47年来江苏省梅雨量年际变化大致可以分为少雨和多雨两个阶段；梅雨的区域分布特征是苏南及沿江地带梅雨量的年波动不及淮北地区；各年份梅雨持续的天数相差极为悬殊，而其降水极值除个别年份外大多低于800mm；梅雨量的丰歉常常决定了江苏省的旱涝总趋势，特别的丰梅年和枯梅年对江苏省农业生产和社会经济发展都带来显著的负面影响。     

SUMMER FLOODING AT CHICAGO AND POSSIBLE RELATIONSHIPS TO URBAN-INCREASED HEAVY RAINFALL1

ABSTRACT: : Studies of two measures of flooding in the Chicago metropolitan area reveal a wide range of floods with the magnitude related to recurrence interval expressions of rain intensity. Minor type floods (in basements and underpasses) usually result from localized heavy rains (≤ 3-hour duration) with return intervals of 1 to 2 years, and more major floods result from rains with return intervals of 2 to 5 years (or more). Urban-factors help lead to increases in warm season rain events in Chicago with 1- to 4-year return intervals. These apparently help lead to 10 to 100 percent more flooding events in Chicago than expected. The range of increase varies depending on locale and type of flood, but the increases in storms should be accounted for in drainage designs.     

DETERMINISTIC-SYSTEMIC RELATIONSHIPS IN OVERLAND FLOW ANALYSIS1

ABSTRACT: An analysis of storm runoff is presented, giving primary attention to deterministic-systemic relationships. So that system aspects can be emphasized, other aspects are kept simple; analysis is made for uniform rainfall on a strip of uniform width, limiting direct applicability to small areas. Two relationships between excess rain and time of concentration, one based on hydraulic parameters, the other on hydrologic characteristics, are combined in a solution for peak discharge. The hydraulic expression gives the interrelationship of time of concentration, excess rain, friction, length, and slope. The hydrologic relationship is achieved by converting ordinary intensity-duration curves to corresponding excess rain intensity-duration curves, thereby interrelating excess rain, time of concentration, and loss characteristics. The resulting solution for peak discharge allows for systemic feedback among both hydraulic and hydrologic parameters.     

The Relationship Between Road Accident Severity and Recorded Weather

Road accident severity may be influenced by a number of factors. This article investigates the relationship between weather and road accidents in England and Wales. The weather information recorded on Police Accident Report Forms was taken as the prevailing weather at the time of the accident. At the local authority level, accident severity for the various adverse weather categories of rain, fog, and high winds is compared with the nonhazardous condition of fine weather. Severity ratios are then calculated. Findings establish that accident severity decreases significantly in rain compared with fine weather, while severity in fog shows geographical variation. Evidence for accident severity in high winds remains inconclusive.     

无锡市酸沉降时空分布规律和特征

在大量监测数据的基础上，分析了无锡市降水酸化的现状及发展趋势，并对酸沉降的分布情况及相互关系等特征进行了探讨。