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11.
The lethal toxicity of sediment porewater isolated from samples collected from six United Kingdom estuaries was tested using a Tisbe battagliai bioassay. A selection of Phase 1 toxicity identification evaluation (TIE) procedures was then used to characterise the substances responsible for the measured toxicity. In samples collected in 2000, cationic metals, ammonia, organic compounds were identified as the cause of toxicity in the most toxic sample collected. Some of the toxicity remained uncharacterised. It was shown that the toxicity in samples collected from the same locations in 2001 was due to ammonia. The successful application of the T. battagliai bioassay demonstrates that it is a suitable assay for marine sediment porewater TIE and that combined with simple characterisation procedures allow an initial assessment to be made on the type of substances responsible for the measured toxicity.  相似文献   
12.
OBJECTIVE: To explore the epidemiology of pedestrian deaths in Dallas County, Texas, and to compare factors associated with pedestrian deaths on expressways versus those that occurred on other roadways. METHODS: We studied all pedestrian deaths among persons 15 years of age or older in Dallas County, Texas, from 1997 to 2004 by linking data from Medical Examiner's office, the Fatality Analysis Reporting System, and local police records. Univariate and multivariate analysis compared various factors associated with death on an expressway. RESULTS: Among 437 pedestrian deaths who were 15 years of age or older, 197 (45%) occurred on expressways; the proportion that occurred on expressways was highest among 15- to 29-year-olds (65%) and was lower with advancing age group (p < 0.01, chi square for trend). At least 36% of these expressway-related pedestrian deaths were known to have been "unintended pedestrians," who had exited a vehicle after being on the roadway, compared with 11% of pedestrian deaths on surface streets (OR 4.6, 95% CI, 2.7-8.1), and this was also highest among younger age groups. Pedestrian deaths on an expressway, compared with deaths on surface streets, remained strongly associated with having been an "unintended pedestrian" (OR 6.2, 95% CI, 3.1-14.0), after controlling for several other variables, including age, sex, race, nighttime of crash, and alcohol involvement. CONCLUSIONS: Expressways are the predominant site of fatal pedestrian crashes among young adults in this urban area. Since many of these deaths were "unintended pedestrians," procedures for management of occupants of disabled vehicles on expressways could have a large impact on pedestrian deaths in young adults.  相似文献   
13.
Regional Environmental Change - Sea level is projected to rise over the coming decades, further increasing the extent of flooding hazards in coastal communities. Efforts to address potential...  相似文献   
14.
Environment Systems and Decisions - Rural areas face well known and distinctive health care challenges that can limit their resilience in the face of health emergencies such as the COVID-19...  相似文献   
15.
Objective: Survival risk ratios (SRRs) and their probabilistic counterpart, mortality risk ratios (MRRs), have been shown to be at odds with Abbreviated Injury Scale (AIS) severity scores for particular injuries in adults. SRRs have been validated for pediatrics but have not been studied within the context of pediatric age stratifications. We hypothesized that children with similar motor vehicle crash (MVC) injuries may have different mortality risks (MR) based upon developmental stage and that these MRs may not correlate with AIS severity.

Methods: The NASS-CDS 2000–2011 was used to define the top 95% most common AIS 2+ injuries among MVC occupants in 4 age groups: 0–4, 5–9, 10–14, and 15–18 years. Next, the National Trauma Databank 2002–2011 was used to calculate the MR (proportion of those dying with an injury to those sustaining the injury) and the co-injury-adjusted MR (MRMAIS) for each injury within 6 age groups: 0–4, 5–9, 10–14, 15–18, 0–18, and 19+ years. MR differences were evaluated between age groups aggregately, between age groups based upon anatomic injury patterns and between age groups on an individual injury level using nonparametric Wilcoxon tests and chi-square or Fisher's exact tests as appropriate. Correlation between AIS and MR within each age group was also evaluated.

Results: MR and MRMAIS distributions of the most common AIS 2+ injuries were right skewed. Aggregate MR of these most common injuries varied between the age groups, with 5- to 9-year-old and 10- to 14-year-old children having the lowest MRs and 0- to 4-year-old and 15- to 18-year-old children and adults having the highest MRs (all P <.05). Head and thoracic injuries imparted the greatest mortality risk in all age groups with median MRMAIS ranging from 0 to 6% and 0 to 4.5%, respectively. Injuries to particular body regions also varied with respect to MR based upon age. For example, thoracic injuries in adults had significantly higher MRMAIS than such injuries among 5- to 9-year-olds and 10- to 14-year-olds (P =.04; P <.01). Furthermore, though AIS was positively correlated with MR within each age group, less correlation was seen for children than for adults. Large MR variations were seen within each AIS grade, with some lower AIS severity injuries demonstrating greater MRs than higher AIS severity injuries. As an example, MRMAIS in 0- to 18-year-olds was 0.4% for an AIS 3 radius fracture versus 1.4% for an AIS 2 vault fracture.

Conclusions: Trauma severity metrics are important for outcome prediction models and can be used in pediatric triage algorithms and other injury research. Trauma severity may vary for similar injuries based upon developmental stage, and this difference should be reflected in severity metrics. The MR-based data-driven determination of injury severity in pediatric occupants of different age cohorts provides a supplement or an alternative to AIS severity classification for pediatric occupants in MVCs.  相似文献   
16.
Wetlands provide a variety of ecological services, but are attractive sites for many development activities. Between the mid-1950's and mid-1970's about 550,000 acres, or about 0.5 percent, of the vegetated wetlands remaining in the conterminous states were converted to other uses each year. About 80 percent of these losses involved draining and clearing of inland wetlands for agricultural purposes. Recent reductions in national wetland conversion rates are due primarily to declining rates of agricultural drainage and secondarily to government programs that regulate wetlands use. Several governmental policies and programs exist that either encourage or discourage wetland conversions. Section 404 of the Clean Water Act is the major tool for Federal involvement in controlling the conversion of wetlands to other uses. The 404 program, in combination with State regulatory programs, is responsible for reducing annual conversions nationwide by about 50 percent of what is applied for, or 50,000 acres of wetlands per year, primarily through project modifications. Coastal wetlands are reasonably well protected. Inland, freshwater wetlands are generally poorly protected. Efforts to protect wetlands, given a set level of resources, could be improved by categorizing wetlands according to their relative importance and focusing existing wetland programs on high value wetlands.  相似文献   
17.
Summary A model of risk-sensitive foraging based on a continuously foraging but interruptable predator is developed and tested in a simple choice experiment using common shrews.Given a choice of two feeding stations, shrews behaved in accordance with the broad predictions of the model. Having been trained below their estimated food requirement, shrewss preferred the station y elding the higher mean reward rate, but prefereence for a constant (constant reward rate) or risky variable reward rate) station was influenced by experience of variance in reward rate at the risky station.Preference was influenced most clearly by experience of reward rate variance during tests rather than training.  相似文献   
18.
Objective: Appropriate treatment at designated trauma centers (TCs) improves outcomes among injured children after motor vehicle crashes (MVCs). Advanced Automatic Crash Notification (AACN) has shown promise in improving triage to appropriate TCs. Pediatric-specific AACN algorithms have not yet been created. To create such an algorithm, it will be necessary to include some metric of development (age, height, or weight) as a covariate in the injury risk algorithm. This study sought to determine which marker of development should serve as a covariate in such an algorithm and to quantify injury risk at different levels of this metric.

Methods: A retrospective review of occupants age < 19 years within the MVC data set NASS-CDS 2000–2011 was performed. R2 values of logistic regression models using age, height, or weight to predict 18 key injury types were compared to determine which metric should be used as a covariate in a pediatric AACN algorithm. Clinical judgment, literature review, and chi-square analysis were used to create groupings of the chosen metric that would discriminate injury patterns. Adjusted odds of particular injury types at the different levels of this metric were calculated from logistic regression while controlling for gender, vehicle velocity change (delta V), belted status (optimal, suboptimal, or unrestrained), and crash mode (rollover, rear, frontal, near-side, or far-side).

Results: NASS-CDS analysis produced 11,541 occupants age < 19 years with nonmissing data. Age, height, and weight were correlated with one another and with injury patterns. Age demonstrated the best predictive power in injury patterns and was categorized into bins of 0–4 years, 5–9 years, 10–14 years, and 15–18 years. Age was a significant predictor of all 18 injury types evaluated even when controlling for all other confounders and when controlling for age- and gender-specific body mass index (BMI) classifications. Adjusted odds of key injury types with respect to these age categorizations revealed that younger children were at increased odds of sustaining Abbreviated Injury Scale (AIS) 2+ and 3+ head injuries and AIS 3+ spinal injuries, whereas older children were at increased odds of sustaining thoracic fractures, AIS 3+ abdominal injuries, and AIS 2+ upper and lower extremity injuries.

Conclusions: The injury patterns observed across developmental metrics in this study mirror those previously described among children with blunt trauma. This study identifies age as the metric best suited for use in a pediatric AACN algorithm and utilizes 12 years of data to provide quantifiable risks of particular injuries at different levels of this metric. This risk quantification will have important predictive purposes in a pediatric-specific AACN algorithm.  相似文献   

19.
Currently available compilations of methods of air analysis are listed. Collaborative testing is urgently needed to reconcile differences and to demonstrate the accuracy of these methods. The Analytical Methods Evaluation Service of the National Center for Air Pollution Control conducted a survey of the instruments and manual methods of analysis in use. Responses are tabulated from about 80 laboratories, in 28 states and 3 foreign countries. Sulfur dioxide was the most widely measured pollutant. The first collaborative study organized by the Analytical Methods Evaluation Service is described. The purpose was to evaluate the permeation tube technique as a primary standard method for generating known sulfur dioxide concentrations for instrument calibration and methods testing. Although a good beginning has been made, the testing of methods for measuring air pollutants has barely begun.  相似文献   
20.
Air pollution abatement policies must be based on quantitative information on current and future emissions of pollutants. As emission projections uncertainties are inevitable and traditional statistical treatments of uncertainty are highly time/resources consuming, a simplified methodology for nonstatistical uncertainty estimation based on sensitivity analysis is presented in this work. The methodology was applied to the “with measures” scenario for Spain, concretely over the 12 highest emitting sectors regarding greenhouse gas and air pollutants emissions. Examples of methodology application for two important sectors (power plants, and agriculture and livestock) are shown and explained in depth. Uncertainty bands were obtained up to 2020 by modifying the driving factors of the 12 selected sectors and the methodology was tested against a recomputed emission trend in a low economic-growth perspective and official figures for 2010, showing a very good performance.

Implications:?A solid understanding and quantification of uncertainties related to atmospheric emission inventories and projections provide useful information for policy negotiations. However, as many of those uncertainties are irreducible, there is an interest on how they could be managed in order to derive robust policy conclusions. Taking this into account, a method developed to use sensitivity analysis as a source of information to derive nonstatistical uncertainty bands for emission projections is presented and applied to Spain. This method simplifies uncertainty assessment and allows other countries to take advantage of their sensitivity analyses.  相似文献   
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