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181.
INTRODUCTION: Aggressive driving encompasses a continuum of behaviors that range from extreme acts, such as shootings, to less severe manifestations, such as arguments and gestures. It is clear from the available data that aggressive driving is not uncommon and very risky. However, little is known about the opinions and practices of drivers. The purpose of this study was to help bridge these gaps. METHODS: The data were gathered by means of a public opinion poll among a representative sample of 1,201 Canadian drivers. Univariate frequency distributions and 95% confidence intervals were calculated and logistic regression and generalized linear latent models were used to summarize the data. RESULTS: It was found that the issue of aggressive driving is a significant one as a considerable percentage of drivers admits to it. The results coming from the logistic regression and the generalized linear latent model suggest that male and younger drivers are more likely to behave aggressively in traffic and that behaving more aggressively is associated with a history of traffic tickets. DISCUSSION: When gauging people's attitudes, opinions, and behaviors, it becomes clear that aggressive driving is a considerable problem. There also seems to be a need for a better understanding of which specific behaviors respondents associate with the generic term "aggressive driving." IMPACT ON INDUSTRY: Results from this study further emphasize the need of increasing the aggressive driving knowledge base. 相似文献
182.
阐述了利用遗传算法优化污染损害指数评价模型中参数时的优点和不足,提出采用普适质数公式对污染损害指数评价模型中参数进行线性优化时,可以大幅简化优化过程,便于实际应用.将适用于大气质量评价的普适指数公式与通过GA优化的评价结果进行比对,证实了该公式在线性优化中的可行性. 相似文献
183.
Western European landscapes have drastically changed since the 1950s, with agricultural intensifications and the spread of
urban settlements considered the most important drivers of this land-use/land-cover change. Losses of habitat for fauna and
flora have been a direct consequence of this development. In the present study, we relate butterfly occurrence to land-use/land-cover
changes over five decades between 1951 and 2000. The study area covers the entire Swiss territory. The 10 explanatory variables
originate from agricultural statistics and censuses. Both state as well as rate was used as explanatory variables. Species
distribution data were obtained from natural history collections. We selected eight butterfly species: four species occur
on wetlands and four occur on dry grasslands. We used cluster analysis to track land-use/land-cover changes and to group communes
based on similar trajectories of change. Generalized linear models were applied to identify factors that were significantly
correlated with the persistence or disappearance of butterfly species. Results showed that decreasing agricultural areas and
densities of farms with more than 10 ha of cultivated land are significantly related with wetland species decline, and increasing
densities of livestock seem to have favored disappearance of dry grassland species. Moreover, we show that species declines
are not only dependent on land-use/land-cover states but also on the rates of change; that is, the higher the transformation rate from small to large farms, the higher the loss of dry grassland species.
We suggest that more attention should be paid to the rates of landscape change as feasible drivers of species change and derive
some management suggestions. 相似文献
184.
A significant number of pipeline operators use pipeline integrity management (PIM) to improve pipeline safety and reliability. Risk assessment is a critical step in PIM, because it determines the necessity of conducting the following steps in PIM for certain pipelines. Risk acceptance criteria are required in the process of risk assessment. Individual risk and societal risk are most frequently adopted as the two indicators of the risk acceptance criteria. To the best of the authors’ knowledge, quantitative societal risk acceptance criteria, especially for gas distribution pipelines, do not exit. The aim of this paper is to establish the societal risk acceptance criteria for gas distribution pipelines. Hence, FN curves were established using historical incident data from 2002 to 2017 provided by the U.S. Department of Transportation (DOT). Linear regression and the ALARP principle are used in evaluating the limits of the negligible line and intolerable line to obtain a graphical societal risk acceptance criterion for gas distribution pipelines. A line having a slope of −1.224, and an anchor point of (1, 8.413 × 10−7) is proposed as the negligible line. Further, the intolerable line has a slope of −1.224, and an anchor point of (1, 2.524 × 10−6). Both the negligible risk and the intolerable risk for the gas distribution pipeline are lower than the current societal risk acceptance criteria for hazardous installations. The reasons for these relatively lower risk acceptance criteria are discussed. 相似文献
185.
Mohammad Dadashzadeh Faisal Khan Kelly Hawboldt Rouzbeh Abbassi 《Process Safety and Environmental Protection》2011,89(5):295-299
Fugitive emission rate quantification in an oil and gas facility is an important step of risk management. There are several studies conducted by the United States Environmental Protection Agency (USEPA) and American Petroleum Institute (API) proposing methods of estimating emission rates and factors. Four major approaches of estimating these emissions, in the order of their accuracy, are: average emission factor approach, screening ranges emission factor approach, USEPA correlation equation approach, and unit-specific correlation equation approach. The focus of this study is to optimize the USEPA correlation equations to estimate the emission rate of different units in an oil and gas facility. In the developed methodology, the data available from USEPA (1995) is used to develop new sets of equations. A comparison between USEPA correlation equations and the proposed equations is performed to define the optimum sets of equations. It is observed that for pumps, flanges, open-ended lines, and others, the proposed developed equations provide a better estimation of emission rate, whereas for other sources, USEPA equations supply the better estimate of emission rate. 相似文献
186.
应用三维空气质量模型(Model-3/CMAQ)和积分过程速率(IPR)分析工具对2017年7月22~31日夏季4次台风持续影响下中山市7月首次出现的持续6d的O3污染事件进行了详细分析,识别了O3 8h浓度最大值时段主导的大气物理过程和大气化学过程,并计算了不同源、汇过程对本地O3浓度的贡献.研究结果表明,污染时段化学过程对O3的源贡献高于非污染时段,化学过程贡献增加,说明光化学反应过程更加活跃;台风带来的外来气团经过上风向高污染物排放区域时,化学过程贡献显著上升,与非经过高污染物排放区域相比,污染时段的化学过程对中山市O3源过程的浓度贡献高2.4%~6.5%;污染时段,水平输送对中山市大气O3源过程的浓度贡献在56.6%~92.6%之间.因此,污染期间强化本地排放源的管控,减少O3生成贡献的同时,结合区域气团路径分析,精准识别污染协同管控区域,上风向污染物高排放区域实施协同减排措施,实现区域联防联控. 相似文献
187.
Gervasio Pieiro Susana Perelman Juan P. Guerschman Jos M. Paruelo 《Ecological modelling》2008,216(3-4):316-322
A common and simple approach to evaluate models is to regress predicted vs. observed values (or vice versa) and compare slope and intercept parameters against the 1:1 line. However, based on a review of the literature it seems to be no consensus on which variable (predicted or observed) should be placed in each axis. Although some researchers think that it is identical, probably because r2 is the same for both regressions, the intercept and the slope of each regression differ and, in turn, may change the result of the model evaluation. We present mathematical evidence showing that the regression of predicted (in the y-axis) vs. observed data (in the x-axis) (PO) to evaluate models is incorrect and should lead to an erroneous estimate of the slope and intercept. In other words, a spurious effect is added to the regression parameters when regressing PO values and comparing them against the 1:1 line. Observed (in the y-axis) vs. predicted (in the x-axis) (OP) regressions should be used instead. We also show in an example from the literature that both approaches produce significantly different results that may change the conclusions of the model evaluation. 相似文献
188.
分光光度法测定余氯的线性范围探讨 总被引:3,自引:0,他引:3
用分光光度法测定水样中的余氯,按照国际GB11898-89中的要求,整个浓度范围内(余氯0-5.00mg/L)所制得的标准曲线的相关系数在0.99-0.999之间。经对其标准曲线的线性范围进行探讨发现,当余氯的浓度范围为0-1.00mg/L时,标准曲线的线性较好,相关系数>0.999;当余氯的浓度>1.00mg/L,所绘制的标准曲线呈负偏离现象,相关系数<0.999。 相似文献
189.
190.
The US Army Corps of Engineers, the US Bureau of Reclamation, and the Bonneville Power Administration initiated the Columbia River System Operation Review (SOR) in 1990. The SOR will assist agencies in comparing the benefits and risks to Columbia River uses and natural resources from alternative strategies for using Columbia River water. Focusing on 14 federal dams within the basin, the agencies are attempting to improve on the efficient and coordinated use of the Columbia River system. An initial screening of all potential strategies of reservoir operation was necessary to reduce the number of possibilities to a limited set for detailed analysis. To that end, the Resident Fish Work Group of the SOR developed spreadsheet models capable of assessing the impacts of different management strategies on resident fish at six storage reservoirs. The models include biological, physical, and hydrological relationships important to resident fish specific to each reservoir. Alternatives that kept the reservoirs near full pool and held stable during the growing season resulted in positive benefits to resident fish at all locations modeled. Conversely, alternatives designed to improve anadromous fish survival with increased instream flow generally had a negative impact on the resident fish in the reservoirs modeled. The models developed for resident fish in the screening analysis phase of the SOR were useful in assessing the relative impact to resident fish from a large number of alternatives. The screening analysis demonstrated that future analytical efforts must consider trade-offs among river uses/resource groups, among reservoirs throughout the basin, and among resident fish species within a reservoir.Pacific Northwest Laboratory is operated by Battelle Memorial Institute for the US Department of Energy under contract DE-AC06-76RLO 1830. 相似文献