首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   447篇
  免费   4篇
  国内免费   11篇
安全科学   26篇
废物处理   17篇
环保管理   93篇
综合类   51篇
基础理论   81篇
污染及防治   123篇
评价与监测   42篇
社会与环境   26篇
灾害及防治   3篇
  2023年   5篇
  2022年   12篇
  2021年   15篇
  2020年   4篇
  2018年   10篇
  2017年   9篇
  2016年   15篇
  2015年   11篇
  2014年   14篇
  2013年   48篇
  2012年   10篇
  2011年   24篇
  2010年   19篇
  2009年   16篇
  2008年   20篇
  2007年   22篇
  2006年   19篇
  2005年   11篇
  2004年   16篇
  2003年   17篇
  2002年   17篇
  2001年   7篇
  2000年   5篇
  1999年   4篇
  1998年   9篇
  1997年   10篇
  1996年   7篇
  1995年   3篇
  1993年   7篇
  1992年   6篇
  1991年   5篇
  1990年   4篇
  1989年   3篇
  1987年   3篇
  1986年   2篇
  1985年   5篇
  1984年   4篇
  1983年   2篇
  1982年   4篇
  1981年   2篇
  1979年   4篇
  1978年   2篇
  1975年   2篇
  1973年   2篇
  1964年   2篇
  1963年   2篇
  1958年   2篇
  1957年   2篇
  1956年   3篇
  1955年   3篇
排序方式: 共有462条查询结果,搜索用时 46 毫秒
451.
Potters and sculptors perform their work in very awkward postures. The purpose of this study was to analyse these postures. The modified Nordic questionnaire was used to analyse musculoskeletal discomfort. Rapid entire body assessment (REBA) and rapid upper limb assessment (RULA) were used to evaluate the subjects’ postures. There were no significant differences between times of discomfort and the group of subjects. However, there were significant differences in discomfort in different body parts. The analysis indicated that various body postures were harmful to the subjects and that there were profound deviations from natural curvature of various body parts due to awkward body postures. Ergonomics intervention was required to improve the quality of life.  相似文献   
452.
Environmental Science and Pollution Research - The rapid degradation, overexploitation, and encroachment of floodplain wetlands have led to considerable decline in fish diversity and production...  相似文献   
453.
The researchers collected and examined 10 years of petroleum-related accidents in the state capital of New York (NY) to develop a preliminary model (N = 1,005). The goal of the research was to propose an evidence-driven methodology to inform urban environmental policy making and emergency preparedness planning. Albany, NY, USA, was a preferentially selected sample site since it was a large city in an environmentally sensitive region with controversial oil–gas fracking policies being debated within government. The objective of the study was to develop a predictive model from petroleum accident data using nonparametric inferential statistical techniques to avoid the constraints inherent of normal distribution assumptions. A statistically significant model was formulated and tested, which indicated that the probability of petroleum accidents in the gas–oil industry was almost six times higher than their occurrence by people in other groups, such as electricity generation, transportation, hospitals, universities, warehouses, government, businesses, and residences.  相似文献   
454.
An experiment was conducted to determine the influence the time of brush-cutting can have on plant regrowth and attractiveness to herbivores that browse in linear corridors. The influence of cutting time on leaf flush and senescence, shoot morphometry, and biomass was measured for 3 consecutive years after initial brush-cutting. Results indicate that morphological and phenological attributes of three woody deciduous plants were influenced by the timing of brush-cutting for up to 3 years after initial cutting. Brush-cutting generally stimulated plants to produce larger than normal shoots and delay leaf senescence. The degree to which plants were affected, however, varied with the timing of initial cutting and the species in question. Generally, plants cut later in the year resprouted more vigorously and were taller in the third year after cutting but produced less overall biomass than when cut earlier. In the years following brush-cutting, plants cut earlier flushed leaves earlier in the spring but delayed leaf senescence in the fall when compared to uncut controls. Results of these trials suggest that brush-cutting time influences plant response and several plant attributes known to influence plant attractiveness to moose and other herbivores. We therefore recommend that roadside and railside vegetation management plans consider the influence of cutting time on plant regrowth. Such considerations can ensure that brush is cut to reduce the attractiveness of plant regrowth in these linear corridors, reduce the utilization of such brush by herbivores, and, as such, mitigate collision risk between motorists and herbivores such as moose.  相似文献   
455.
A high-efficiency particulate air (HEPA)-carbon filtration system was developed by the Access Business Group, LLC, to reduce the indoor levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The HEPA filter removes the particle-bound PCDD/Fs, and the carbon filter removes the gaseous fraction. Because of the toxicity of PCDD/Fs, it is very difficult to handle them in the laboratory. In this study, mathematical modeling was performed to evaluate the performance of the HEPA-carbon filtration system for PCDD/Fs removal and to optimize its design and operation. The model was calibrated with experimental data conducted with toluene in a sealed room. Model simulations with four selected congeners demonstrated that it takes approximately 1 hr for the indoor air treatment system to reach the maximum removal efficiency and that the carbon air filter has a life time of 10(7) yr for dioxin removal. Given a zero emission from the HEPA filter, the overall removal efficiency is 78.7% for 2,3,7,8-tetrachloro dibenzo-p-dioxins, 89.8% for octa-chlorodibenzodioxin, 78% for tetra-chlorodibenzofuran, and 89.8% for octa-chlorodibenzofuran. The larger the mass emission from the HEPA filter, the lower the overall removal efficiency, and the larger the ratio of the filter flow rate (Q(f)) to the room flow rate (Q), the higher the overall removal efficiency. When the ratio of Q(f)/Q is 15, an overall removal efficiency of 90% can be reached for all four of the selected compounds. The removal of the four selected compounds does not change as the relative humidity increases < or = 90%.  相似文献   
456.
Using a questionnaire derived from previous research, MBA students in a semester‐long negotiation course rated 30 deceptive negotiation tactics on a 7‐point appropriate–inappropriate scale. Factor analysis of these ratings yielded five primary factors (replicating previous findings) representing a lay model of unethical tactics in negotiation contexts. The emergent factors are: I, traditional competitive bargaining; II, attacking an opponent's network; III, misrepresentation/lying; IV, misuse of information; and V, false promises. The five factors may be reliably measured using a 16‐item questionnaire, introduced here, called the ‘Self‐reported Inappropriate Negotiation Strategies Scale’, (or SINS scale). Analyses of scale ratings by participant demographics yielded some interesting results including: a tendency for women to be more averse to questionable tactics than men; a greater willingness for self‐rated ‘competitive’ individuals to endorse such tactics; and differences in willingness to endorse tactics according to variables such as undergraduate major, years of work experience, and nationality. Willingness to endorse less ethical tactics did not directly relate to actual negotiation performance. Directions for future research, and further uses of the SINS scale, are discussed. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
457.
458.
Environmental Science and Pollution Research - This study analyzes the effects of credit constraints on technical efficiency of Boro rice growers in the district of Pabna in Bangladesh. Using a...  相似文献   
459.
Short-lived, fast-growing species that contribute greatly to global capture fisheries are sensitive to fluctuations in the environment. Uncertainties in exact stock–environment relationships have meant that environmental variability and extremes have been difficult to integrate directly into fisheries management. We applied a management strategy evaluation approach for one of Australia's large prawn stocks to test the robustness of harvest control rules to environmental variability. The model ensemble included coupled environmental-population models and an alternative catchability scenario fitted to historical catch per unit effort data. We compared the efficacy of alternative management actions to conserve marine resources under a variable environment while accounting for fisher livelihoods. Model fits to catch per unit effort were reasonably good and similar across operating models (OMs). For models that were coupled to the environment, environmental parameters for El Niño years were estimated with good associated precision, and OM3 had a lower AIC score (77.61)  than the base model (OM1, 80.39), whereas OM2 (AIC 82.41) had a similar AIC score, suggesting the OMs were all plausible model alternatives. Our model testing resulted in a plausible subset of management options, and stakeholders selected a permanent closure of the first fishing season based on overall performance of this option; ability to reduce the risk of fishery closure and stock collapse; robustness to uncertainties; and ease of implementation. Our simulation approach enabled the selection of an optimal yet pragmatic solution for addressing economic and conservation objectives under a variable environment with extreme events.  相似文献   
460.
Environmental Science and Pollution Research - Aulacoseira granulata (Ehrenberg) Simonsen 1979 are considered as the eco-variable species which varies in density and diversity along with their...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号