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201.
202.
1995年气候对交通系统的影响   总被引:1,自引:0,他引:1  
张清 《灾害学》1996,11(2):76-79
根据气象部门和交通部门的资料,对1995年气候条件对我国交通系统造成的影响进行了分析评述,其中影响最大的是暴雨洪水,其它气候灾害还有雾、雪、风及高温等,使我们对影响交通系统的气候灾害有了进一步的认识。  相似文献   
203.
本文利用光学中的Hugens-Fresnl原理和Kir-chof近似理论,建立了由点声源组成的随机车辆流模型,探讨声波通过屏障间狭缝的衍射,从而确定交通噪声对临街建筑群中某测点的贡献  相似文献   
204.
PROBLEM: The expected substantial increase in people aged 65 or older is important for those concerned about transportation injuries. However, much of the previous research concentrates on older drivers and overlooks the fact that vehicle and crash factors may provide significant explanations of older occupant injury rates. METHOD: Differences across age groups are explored using two nationwide travel surveys, crash involvement, fatalities, and injuries from crash databases and an ordered probit model of injury severity. RESULTS AND DISCUSSION: Two noticeable differences that help explain injury risk are that older people are more likely to travel in passenger cars than younger people who frequently use light trucks, and that seriously injured older occupants are more likely to be involved in side-impact crashes than their younger counterparts. IMPACT: Increased attention to vehicle engagement in side-impact crashes and to vehicle technologies that can help drivers avoid side collisions would be particularly helpful for older occupants.  相似文献   
205.
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Increased attentions to vehicle emission of NH3 have been paid since it is generally regarded as an important source in urban areas. Here, we developed a movable instrument based on Differential Optical Absorption Spectroscopy (DOAS) principle for detecting on-road NH3, which can avoid the losses in the sampling process attributed to the non-sampling methods. For this mobile DOAS, the temporal resolution, detection limit and relative error for NH3 were 1 min, 2.29 ppbv and 4.57% ± 2.44%, respectively. By employed to the on-road measurements along the arterial highway in Shanghai, the spatial distributions of NH3 and NO were obtained, and their dependence of traffic and road conditions were studied. The slopes of linear regression between NH3 and NO were 0.40, 0.02 and 0.07 on the Middle Ring Road, Outer Ring Road and Chongming Island Ring Road. It indicates that light gasoline vehicles (LGVs) were found to be the main contributor to NH3 emissions, while heavy-duty diesel vehicles (HDVs) mainly emitted NO. Based on the measured NH3 in the tunnel, the mileage-based NH3 emission factor per vehicle was estimated to be 17.9 ± 6.3 mg/km. The reported open-path instrument can be broadly used in on-road pollutant monitoring or vehicle emissions, and the measurements can reveal the real situation of emission characteristics, even find the abnormal operations of vehicle catalyst system.  相似文献   
206.
    
During the 2013 and 2015 Lanzhou International Marathon Events(LIME1 and LIME2),the local government made a significant effort to improve traffic conditions and air quality by implementing traffic restriction measures. To fill the gap in information on the effect of short-period(several hours)traffic control on urban air quality,submicron particle size distributions and meteorological data were measured simultaneously during June 2013 and June 2015 in urban Lanzhou. The number and surface area concentrations of particles in the100–200 nm range declined by 67.2% and 65.0% for LIME1 due to traffic control,while they decreased by 39.2% and 37.1% for LIME2. The impact of traffic restriction on air pollution near the sampling site lagged behind the traffic control period for LIME2. In addition,the effect of traffic restriction on air pollution near the sampling site was dependent on the distance between the relative orientation of the sampling site and traffic-restricted zones,as well as meteorological conditions such as wind direction. The influence of traffic restrictions on the particle concentrations differed for different particle sizes. The size range most affected by traffic restriction was 60–200 and 60–300 nm for number and surface area concentrations in the urban environment,respectively,while for the particle volume concentration it was the 100–600 nm range. This study will provide a basis for implementation of future urban traffic-induced particulate pollution control measures.  相似文献   
207.
对42名分属于典型外向稳定、内向稳定、外向不稳定、内向不稳定4种人格类型的受试者,进行30min、(90±2)dB(A)的交通噪声暴露,测定每搏左心室作功(LVSW)、总外周阻力(TPR)、每分心输出量(CO)、平均动脉压(MAP)等指标。结果表明:外向不稳定型组LVSW在噪声暴露中及暴露后均显著下降。4组受试者的TPR均显著上升,其中内向不稳定型TPR在噪声停止20min时依然处于显著的高水平。内向不稳定组CO在暴露中和暴露后均显著下降,其余3组CO在噪声暴露后下降。外向稳定型组的MAP在噪声暴露即刻、暴露中和暴露后均显著上升。结果提示:噪声暴露能够影响受试者的心功能,对不稳定型受试者的影响明显大于稳定型受试者。  相似文献   
208.
通过对温州市区5条主干道部分路段交通噪声的实地监测,在非交通高峰期,87.5%的测点监测值超过昼间70dB限值要求,其中31%的测点交通噪声属于重度污染.根据目前国内外噪声的各种控制方法,结合温州实际情况,提出了减轻噪声污染的一些措施和建议。  相似文献   
209.
通过在48条交通路段进行布点监测,监测数据采用模糊聚类分析的方法,优化出切合实际的铁岭市城市交通噪声的测点.  相似文献   
210.
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Traffic is a main source of air pollutants in urban areas and consequently daily peak exposures tend to occur during commuting. Personal exposure to particulate matter (PM) was monitored while cycling and travelling by bus, car and metro along an assigned route in Lisbon (Portugal), focusing on PM2.5 and PM10 (PM with aerodynamic diameter <2.5 and 10 µm, respectively) mass concentrations and their chemical composition. In vehicles, the indoor-outdoor interplay was also evaluated. The PM2.5 mean concentrations were 28?±?5, 31?±?9, 34?±?9 and 38?±?21?µg/m3 for bus, bicycle, car and metro modes, respectively. Black carbon concentrations when travelling by car were 1.4 to 2.0 times higher than in the other transport modes due to the closer proximity to exhaust emissions. There are marked differences in PM chemical composition depending on transport mode. In particular, Fe was the most abundant component of metro PM, derived from abrasion of rail-wheel-brake interfaces. Enhanced concentrations of Zn and Cu in cars and buses were related with brake and tyre wear particles, which can penetrate into the vehicles. In the motorised transport modes, Fe, Zn, Cu, Ni and K were correlated, evidencing their common traffic-related source. On average, the highest inhaled dose of PM2.5 was observed while cycling (55 µg), and the lowest in car travels (17 µg). Cyclists inhaled higher doses of PM2.5 due to both higher inhalation rates and longer journey times, with a clear enrichment in mineral elements. The presented results evidence the importance of considering the transport mode in exposure assessment studies.  相似文献   
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