Objective: With increasing traffic volume and urban development, increasing numbers of underground tunnels have been constructed to relieve conflict between strained land and heavy traffic. However, as more long tunnels are constructed, tunnel traffic safety is becoming increasingly serious. Thus, it is necessary to acquire their implications and impacts. This study examined 4,539 traffic accidents that have occurred in 14 Shanghai river-crossing tunnels for the period 2011–2012 and analyze the correlation between potential factors and accident injury severity.
Methods: An ordered logit model was developed to examine the correlation between potential factors and accident injury severity.
Results: Results show that increased injury severity is associated with male drivers, drivers aged 65 years or older, accident time from midnight to dawn, weekends, wet road surface, goods vehicles, 3 or more vehicles, 4 or more lanes, middle speed limits (50–79 km/h), zone 3, extra-long tunnels (over 3,000 m), and maximum longitudinal gradient.
Conclusions: This article aims to provide useful information for engineers to develop interventions and countermeasures to improve tunnel safety in China. 相似文献
Environmental Science and Pollution Research - As the largest developing country in the world, China has witnessed fast-paced urbanization over the past three decades with rapid economic growth. In... 相似文献
A total of 11 sediment samples were collected from the sites along Haihe River?CBohai Bay, with site 1 at the beginning of Haihe River and site 11 in Bohai Bay, about 150 km away from site 1. Quinone profiles were used for the analysis of microbial community as influenced by pollutants in water and sediments, such as heavy metals, and other environmental factors. Nineteen species of quinones were found at site 1 while only six species at sites 10 and 11. Both the diversity of quinone species (DQ) and the number of quinones were higher in the sediments from Haihe River and the near-sea area of Bohai Bay than in those from the deep-sea area. The ?? diversity values were significantly higher, while Jaccard indexes of similarity were much lower among non-contiguous pairs of sites as compared with the contiguous ones. Cluster analysis indicated that quinone profiles may be grouped into two main clusters (sites 1?C7 and sites 8?C11), and there were higher similarities within the groups than between groups. Quinone species composition varied at different sites. Ubiquinones such as UQ-8, UQ-9, and UQ-10 and menaquinones such as MK-6, MK-7, MK-8 were isolated from all the sites and accounted for the largest proportions. Pearson correlation analysis revealed that both the number of quinone species and DQ correlated positively with total organic carbon contents in water and sediments, but negatively correlated with salinity and electroconductivity and did not correlate significantly with heavy metal contents in water. 相似文献
Establishing protected areas is the primary goal and tool for preventing irreversible biodiversity loss. However, the effectiveness of protected areas that target specific species has been questioned for some time because targeting key species for conservation may impair the integral regional pool of species diversity and phylogenetic and functional diversity are seldom considered. We assessed the efficacy of protected areas in China for the conservation of phylogenetic diversity based on the ranges and phylogenies of 2279 terrestrial vertebrates. Phylogenetic and taxonomic diversity were strongly and positively correlated, and only 12.1–43.8% of priority conservation areas are currently protected. However, the patterns and coverage of phylogenetic diversity were affected when weighted by species richness. These results indicated that in China, protected areas targeting high species richness protected phylogenetic diversity well overall but failed to do so in some regions with more unique or threatened communities (e.g., coastal areas of eastern China, where severely threatened avian communities were less protected). Our results suggest that the current distribution of protected areas could be improved, although most protected areas protect both taxonomic and phylogenetic diversity. 相似文献
Environmentally friendly green composites were prepared by blending Wheat gluten (WG) as matrix, dialdehyde starch (DAS) as
filler and glycerol as plasticizer followed by compression molding of the mixture at 110 °C. The properties of the WG/DAS
composite are compared with those of the WG/native wheat starch (NWS) composites. While tensile strength and strain at break
decrease with increasing NWS content in the WG/NWS composites, a small content of DAS could improve tensile strength and strain
at break simultaneously in the WG/DAS composites. The WG/DAS composites exhibit reduced moisture absorption in comparison
with the WG/NEW composites. Formation of chemical bonding between DAS and WG is beneficial for the dispersion of DAS in the
WG matrix and WG/DAS composites exhibit improved mechanical properties and reduced moisture absorption over the WG/NWS composites. 相似文献
Permeable reactive barriers (PRBs) are an alternative technology to treat mine drainage containing sulfate and heavy metals. Two column experiments were conducted to assess the suitability of an organic carbon (OC) based reactive mixture and an Fe0-bearing organic carbon (FeOC) based reactive mixture, under controlled groundwater flow conditions. The organic carbon mixture contains about 30% (volume) organic carbon (composted leaf mulch) and 70% (volume) sand and gravel. The Fe0-bearing organic carbon mixture contains 10% (volume) zero-valent iron, 20% (volume) organic carbon, 10% (volume) limestone, and 60% (volume) sand and gravel. Simulated groundwater containing 380 ppm sulfate, 5 ppm As, and 0.5 ppm Sb was passed through the columns at flow rates of 64 (the OC column) and 62 (the FeOC column) ml d− 1, which are equivalent to 0.79 (the OC column) and 0.78 (the FeOC column) pore volumes (PVs) per week or 0.046 m d− 1 for both columns. The OC column showed an initial sulfate reduction rate of 0.4 µmol g (OC)− 1 d− 1 and exhausted its capacity to promote sulfate reduction after 30 PVs, or 9 months of flow. The FeOC column sustained a relatively constant sulfate reduction rate of 0.9 µmol g (OC)− 1 d− 1 for at least 65 PVs (17 months). In the FeOC column, the δ34S values increase with the decreasing sulfate concentration. The δ34S fractionation follows a Rayleigh fractionation model with an enrichment factor of 21.6‰. The performance decline of the OC column was caused by the depletion of substrate or electron donor. The cathodic production of H2 by anaerobic corrosion of Fe probably sustained a higher level of SRB activity in the FeOC column. These results suggest that zero-valent iron can be used to provide an electron donor in sulfate reducing PRBs. A sharp increase in the δ13C value of the dissolved inorganic carbon and a decrease in the concentration of HCO3− indicate that hydrogenotrophic methanogenesis is occurring in the first 15 cm of the FeOC column. 相似文献